eChapters

Plant diseases, in spite of the various measures adopted to control them, continue to be a major cause of crop losses. At times these losses have been so heavy that they have caused severe famines. Diseases are caused by a wide variety of organisms such as fungi, bacteria, viruses, mycoplasma and nematodes. The diseases may be partially or completely controlled by chemical, cultural and genetic methods. When no single method is effective in controlling a disease, integrated control constituting a combination of the three methods of disease control (chemical, cultural, genetic) may be effective. If host resistance alone is sufficient to check a disease, then it is to be preferred to other methods because it is the least expensive, has no adverse environmental effects and involves no specific action on the part of the farmer, even when only partial, genetic resistance supplements chemical control and makes it more effective in comparison with chemical control on a completely susceptible cultivar.

Many plant diseases have been successfully controlled by exploiting genetic resistance especially where differentiation in the pathogen with respect to resistance genes in the host is lacking. In some cases, even when pathotype differentiation occurs in the pathogen, genetic resistance in combination with other methods has given adequate control. Breeding for resistance to highly variable air-borne fungal pathogens has claimed much time and effort of plant breeders and success has often been transient. The reasons for the shortlived success have become clear from research during the last quarter of a century.

The immediate and long-term objective of modern plant breeding in all countries irrespective of the state of their advancement is increasing the availability of food to meet the calorie-protein requirement of their people. In the past, breeders have concentrated their efforts on increasing the yield of the important crop species. Better adaptation to local environmental conditions, high production and better resistance to the major pests and diseases have been among the priority goals of genetic plant improvement. Yielding ability and stability undoubtedly deserve high priority but enough attention also needs to be paid to improving nutritional characteristics of the plant produce for their maximum utilisation. Awareness of nutritional requirements and the optimal characteristics of crop products to be utilised as food and feed, therefore, becomes an important parameter of breeding effort.

The main source of food in the developing world is cereals which provides 45 to 85 per cent of the total calories and 50 to 80 per cent of the total protein requirements. The consumption of animal proteins, which are nutritionally well balanced, is low and costly and beyond the reach of the low income groups. On the other hand, plant proteins are cheaper to produce and easier to store and transport. All these factors go in favour of increasing the quantity and quality of cereal proteins in order to improve the dietary and nutritional status of the masses in the developing world.

Proteins are made up of about twenty different amino acids. For man, eight of these amino acids, valine, methionine, leucine, isoleucine, threonine, phenylalanine, lysine and tryptophan, are essential (EAA) for constituting a well balanced diet. In impioving the grain quality of cereals consideration should, therefore, be given apart from the content of carbohydrates, fats, minerals and vitamins in the grains, to improving the protein content as also the amino acid composition of the protein.

Most varieties of fruit plants have originated as chance seedlings or through somatic mutation and have been maintained and multiplied through vegetative propagation by fruit growers. The improvement of fruit plants through breeding has not yet attracted the serious attention of the research workers. Unlike field crops, fruit plant breeding is time consuming and laborious. Studies on the mode of inheritance of important economic characters of fruit plants are difficult because of the heterozygous nature of the plants. Moreover, varying degrees of sexual incompatibility have complicated the situation. Due to a long juvenile phase, it takes a long time to identify a useful hybrid. This factor has become a serious handicap because most research workers leave or shift from the programme before tangible results are obtained.

During the last two decades, considerable useful information has been generated on breeding methodology for the improvement of some of the important fruit crops. In this chapter fruits like mango, banana and papaya have been included.

Introduction

Tree improvement through the application of genetic principles is directed towards modifying the heredity of tree populations so that they are able to meet the needs of the forester and the wood based industry. The breeder of annual crop plants resorts to hybridisation, selection, testing of the improved strains, multiplication of improved seeds and finally their release for commercial planting in that logical sequence. But the tree breeder, whose career may be shorter than the life cycle of the tree species taken up for improvement, tends to carry out the above operations in a modified form and often some of the operations are carried out concurrently.

Many of our tree species are wild unselected populations. They are, therefore, expected to exhibit considerable natural variability for many characters and also to respond well to selection for further improvement. Further, altitudinal and latitudinal variation in many characters between populations are expected for those tree species which have a wide geographical distribution. So, the selection of desirable seed sources or provenances is an essential step that is basic to all tree improvement programmes. The right provenance is identified through well laid out provenance trials at a number of locations in the area where the improved selection is to be grown. Further improvement is then planned and executed for exploiting the naturally available intrapopulation variation. The variation normally measured is the phenotypic variation which is the result of interaction of the genotype of the individual with the environment. However, what is essential for selection to be effective is genetic variation for the character under consideration. Genetic variation is assessed by appropriate progeny trials. Since many of the economically valuable characters of tree species are polygenically controlled and exbibit continuous variation, measurements have to be in metric units. The use of biometrical techniques for assessing and analysing this variation, therefore, becomes an essential requirement.

Forage crops are plant species used to feed domestic animals (such as cattle, sheep, goat, pig, and poultry). Both cultivated and wild plants can serve as forage. The domestic animals feed on forages either by grazing or stall feeding (cut fodder eaten in stalls).

Grazing, that is pasturing of animals, is cheaper and allows production of both livestock and dairy produce at a lower cost because no expense is involved in growing, cutting, transporting or feeding. In North and South America, Australia, New Zealand, and in many other temperate countries pastures are widespread and popular because sufficient land is available. While land is cheap and plentiful, labour is scarce and expensive; hence management of natural, and in recent years sown pastures has received much attention.

Until about fifty years ago, the natural grasslands in the Western countries met the minimum needs of the farmers and grassland management was operated at a level comparable to subsistence agriculture of many developing countries. In other words, emphasis was laid on exploitation of natural productivity of the grassland, using a low level of management based on minimum use of inputs like chemical fertilizers. However, it was soon realized that productivity of native grasslands will have to be greatly improved if the high demands for meat and milk were to be adequately met.

In India, however, out of a total cultivable area of about 131.11 million ha less than 2 per cent is utilized for forage crops because feeding the large human population takes the first preference for land use to produce grain and cash crops. It is, therefore, necessary to intensify efforts, particularly in over-populated countries, for a more efficient production of high yielding forage crops to get maximum return out of minimum land.

Breeding methods for vegetable crops are basically similar to those adopted in others like cereals, oilseeds or pulses. Certain aspects, peculiar to vegetables, however, require specific attention: (i) In many cases, the edible part of the plant is not the seed (as cauliflower, cabbage, carrot and onion) and hence while breeding for improved plant part that is used as vegetable, its seed production capacity needs due consideration, (ii) Vegetables like tomato, garden pea and onion are consumed in different forms (fresh or processed) and the end use of the product (like processing quality) has to be taken into account in breeding programmes, (iii) Consumer preferences (as for example in eggplant) size, colour and shape of the vegetable has to be given due emphasis, (iv) Being perishable in nature, keeping quality and suitability for long distance transportation are important attributes in vegetable crops unlike grain crops where bulk handling and haulage can be mechanised, (v) Another peculiarity with vegetable crops is that they vary widely in modes of reproduction necessitating appropriate choice of breeding methods. In addition to vegetatively propagated crops like potato, sweet potato, cassava (tapioca), garlic, pointed gourd or “Parwal (Trichosanthes dioica L.) and ivy gourd or ‘Kundru’ (Coccinia cordifolia L.), there are many seed propagated vegetable crops which are auto- or allogamous or intermediate (Table 1).

Within these broad groups, variations in the extent of cross- or self-pollination, namely, 15-20 per cent natural cross-pollination in chillies and 20-25 per cent natural self-pollination in muskmelon have been recorded.

Since genetic variability is essential for any crop improvement programme, the creation and management of genetic variability becomes central to crop breeding. Experimentally induced mutations provide an important source of variability. An advantage of such created variability is that the starting point can be an agronomically accepted cultivar rather than a genetic stock of no direct commercial value with many undesirable attributes. It should, however, be realized that none of the imposed treatments in a plant system has so far been able to direct a specific change. As a result, following mutagenic treatments, a mixed bag of induced variants is found and many of these may not be of any value. Also, many events take place concurrently in a treated cell to produce variation at several loci within a genome. Because of these reasons it will be unrealistic to expect miracles out of a mutation breeding programme. The desired results can be achieved only when the objectives are clearly defined and the experiments are specifically designed to achieve those objectives. When a mutant of the required type is obtained, we only reach the step of identification of a desired recombinant in a conventional breeding programme and all the succeeding steps of evaluation of the mutant are in no way different from those in the conventional breeding procedures.

Genetic resources deal with germplasm of a given species that provides the necessary genetic variation for the improvement of that species in terms of particular products, increased efficiency and higher levels of productivity. Genetic resources are, in this sense, the building blocks, fundamental not only to a crop improvement programme, but also for the very survival of the species in time and space (Swaminathan, 1983).

As agriculture is becoming more and more intensive and location-specific, plant breeding objectives are becoming more and more complex. Besides high yield, a modern variety is often expected to combine specific duration, nutritional attributes, adaptation to varying soil and water regimes, and resistance to ever-multiplying pests and diseases—to mention only a few of the character combinations. To meet these objectives, a wide range of germplasm must exist, and the plant breeder should have an easy access to the genetic resources.

In conventional breeding for genetic upgradation of yield and other desirable attributes of crop plants, favourable assemblages of genes from two or more parents are made to develop a commercial variety. The important steps of this exercise are: locating the right kind of parents that possess the desired characteristics; making crosses between or among them; handling the segregating generations in an appropriate manner so as to identify the required recombinants; stabilizing the recombinants and finally evaluating their performance in a series of trials. This approach has been very successful in the sense that it has provided increments in productivity continuously. In an analysis done by the American Society of Agronomy on the genetic contributions to yield gains of five major crop plants, it was concluded that sorghum yields increased due to genetic improvements at the rate of 1.2 per cent per year between 1950 and 1980. For corn, the corresponding yield increase was 90 kg/ha/year between 1930 and 1980, which is equivalent to a rate of increase of 1 per cent per year. It was also estimated that 70 per cent of the total gains in corn yields are attributable to genetic improvement and 30 per cent of the yield gains are due to non-seed inputs like fertilizers, pesticides and cultural practices.

In India also, the improvement of productivity of the major food, fibre and several cash crops has been very impressive. The success is due to intensive research in plant breeding resulting in the evolution of varieties with very high genetic yield potentials and the concurrent support from other disciplines that has provided the package of practices which help in the realization of the created potential. In all crop plants, where the breeding efforts have been intensive, the phenomenon of plateauing of yields has become apparent. Wheat provides, perhaps, the best example of the situation. Since the 1970s, when the gains from genetic restructuring of the plant type had been established, major yield increases have not occurred. Since the demands of the future will be undoubtedly much larger, and additional cultivable land will not be available, ways will have to be found for a sizable increase in productivity per unit area in the immediate future. This requirement calls for the development of strategies and procedures that will make dramatic yield gains possible. For meeting the challenge, a continuous search is being made for innovative methods which will give yield increments of a much higher order than those provided by the conventional approach. In this chapter, an attempt has been made to introduce some such promising approaches.

Horticultural plants present a kaleidoscopic scenario from small herbs to very big deep rooted perennial trees. The associated rhizospheres present variable conditions as to supply of nutrients, water and air. The principles governing their physical, chemical and biological properties along with their relationship with plants need to be understood clearly. The plants differ in their requirements at various stages of growth; hence their tissues require constant monitoring of nutrient status for better productivity and quality. As nutrient behavior in soils is governed by soil properties and environmental conditions, measurement of such properties is often required. These include pH, salinity, organic matter, CaCO₃ and texture in drier areas the presence of Na and gypsum (CaSO₄2H₂O) is also of concern.The irrigation water is a source of dissolved salts which are also nutrients and in excess impede water and nutrient relations of soil and plant. It requires a thorough understanding of the principles underlying methods of collection, characterization of water, air and nutrient relations of soil-plant system, monitoring of plant nutrient status, quality of irrigation water and soil and water pollution for effective management of nutrients avoiding pollution.

Soil and plant analysis is a diagnostic instrument for soil fertility and basis for fertilizer recommendation; to know where and where not fertilizer is to be applied. Obtaining accurate and precise values has always being the basis of soil analysis.

Introduction

The objective of soil sampling is to obtain reliable information about a particular soil. The value of laboratory data in soil studies largely depends on effective sampling. Soil sampling is one of the most important aspects in the determination of the properties of the soil. Care in preparation and analysis can overcome the damages of careless or inappropriate sampling in the field (Bates, 1993). Errors arising from sampling are mainly related to spatial variability of the soil. While keeping in mind financial constraints, sampling procedures should be adopted properly to minimize the influence of spatial variability and to maximize the accuracy of mean plot values for the measured soil variables. The obtained soil data should be representative for the whole observation plot, taking into consideration the spatial variability of the soil within the plot.

Importance of soil sampling

Soil sampling and testing are done to provide an estimate of the capacity of the soil to supply adequate amount of nutrients to meet the needs of growing crops and information to its nature and problem. Traditionally, the goal of soil sampling is to develop a representative estimate of a field. A few grams of soil are actually used for the laboratory analysis. That small amount must represent the entire area for which the recommendation is to be made. The samples should be collected in such a way that it would represent the area for which recommendation is to be made.

Introduction

Plant analysis can be defined as the quantitative determination of the concentration of an element or extractable fraction of an element in a sample from a particular part or portion of a crop. From the nutritional standpoint, plant analysis is based on the principle that the concentration of a nutrient within the plant is an integral value of all the factors that have interacted to it. Plant analysis is used as an index of available nutrient element supply. Plant growth or yield are compared with the elemental concentrations contained in the dry matter of the entire plant or plant structures such as leaves, petioles, fruit or grain sampled at different times during their development. Plant analysis gives the overall picture of the nutrient levels within the plant at the time the nutrient was taken. The use of plant analysis is based on the principle that the nutrient level present is as a result of all factors affecting the growth of the plant.

Plant analysis involves the determination of nutrient concentration in diagnostic plant part(s) sampled at recommended growth stage(s) of the crop. In a way plant analysis complements soil analysis. There are reliable sampling criteria and procedures for most of the world’s commercial crops.

Importance

Plant analysis assesses nutrient uptake while soil testing predicts nutrient availability. The two tests are complementary to each other as crop management tools. Plant analysis will detect unseen hidden hunger and confirm visual deficiency symptoms. Toxic levels may also be detected. If it is done early, plant analysis will allow a corrective fertilizer application in the same season.

Three types of water movement within the soil are recognized. They are

1. Saturated flow
2. Unsaturated flow
3. Water vapour movement

Saturated flow

This occurs when the soil pores are completely filled with water. This water moves at water potentials larger than 33 kPa. Saturated flow is water flow caused by gravity’s pull. It begins with infiltration, which is water movement into soil when rain or irrigation water is on the soil surface. When the soil profile is wetted, the movement of more water flowing through the wetted soil is termed percolation.

Hydraulic conductivity can be expressed mathematically as

Soil air, its composition, gaseous exchange

Soil air is a continuation of the atmospheric air. It is in constant motion from the soil pores into the atmosphere and from the atmosphere into the pore space. The circulation of air in the soil and renewal of component gases like oxygen and carbon dioxide is known as soil aeration. Soil aeration is essential for the respiration and survival of soil organisms and plant roots.

Composition of soil air

Soil air contains gases like nitrogen, oxygen, carbon dioxide, water vapour and others. The composition of soil air is different from atmospheric air. Soil air contains more carbon dioxide and less oxygen than atmospheric air. It also contains more water vapour than atmospheric air. The nitrogen content of soil air is almost equal to atmospheric air. (Table below)

Measurement of soil aeration

Oxygen Diffusion Rate (ODR) - the rate at which O₂ in soil air is replenished. ODR decreases with soil depth.

Measurement of ODR in soil

Lemon and Erickson (1952) devised a method for measuring oxygen diffusion in the soil system with the help of platinum micro electrode

Principle

When a certain potential is applied across the platinum electrode and a reference electrode inserted in the soil, oxygen is reduced at the platinum surface. The electric current flowing between two electrodes is proportional to the rate of oxygen reduction. The later, in turn, is related to the rate of oxygen diffusion to the electrode. The oxygen diffusion rate (ODR) is calculated from the measured electric current with the following equation.

In nature there are nearly 300 nuclei, consisting of different elements and their isotopes. Isotopes are nuclei having the same number of protons but different number of neutrons. These techniques are now being used in almost all the areas of plant physiology, soil chemistry and plant biochemistry. In agriculture, radioisotopes are used in the nutritional studies of major and minor elements, plant metabolism, mechanism of photosynthesis studies, and uptake of nutrients and ions mobility in soil. In applying this technique, a minute quantity of radioisotope element is usually mixed with ordinary element of the same kind, the whole batch is termed “tagged” and their role in chemical reactions is traced. The radio labeled fertilizer has been used to study the uptake, retention and utilization of fertilizers.

Radioisotopes are used for determining the function of fertilizer in different plants. The tracer technique is used to study the rate and direction of movement of an element in a plant. For this a radioisotope of that element is injected in the ground near the plant. After a few days the plant is laid on a photographic paper to produce an autoradiograph. The dark areas in the radiograph show the positions reached by the element. This technique gives valuable information regarding the optimum season for fertilizing crops and for poisoning weeds. Use of N¹⁵ in organic fertilizer studies has significantly advanced the understanding of N release from organic materials. Crop residue or green manure studies are relatively simple. These techniques have been extremely useful in determining how residue quality parameters affect mineralization values. Because of the attention focused on nutrient cycling and management studies in recent years, a number of new P isotope techniques have been developed.

Microorganisms being minute and microscopic are ubiquitous. Besides supporting the growth of various biological systems, soil and soil microbes serve as a best medium for plant growth. Soil fauna & flora convert complex organic nutrients into simpler inorganic forms which are readily absorbed by plants.

Soil microbes as nitogen fixers-Symbiotic (Associative): The organisms involved are Rhizobium, Bradyrhizobium in legumes(aerobic): Azospirillum, Azotobacter (grasses), Actinonycetes- Frantkia (with Casuarinas, Alder).

Soil microbes as biocontrol agents: Several ecofriendly bioformulations of microbial origin are used in agriculture for the effective management of plant diseases, insect pests, weeds etc. eg: Trichoderma sp and Gleocladium sp are used for biological control of seed and soil borne diseases. Fungal genera Entomophthora, Beauveria, Metarrhizium and protozoa- Maltesia grandis. Malameba locustiae etc.- are used in the management of insect pests. Nuclear polyhydrosis virus (NPV) is used for the control of Heliothis/American boll worm. Bacteria like Bacillus thuringiensis, Pseudomonas are used in cotton against Angular leaf spot and bollworms.

Degradation of pesticides in soil: Soil receives different toxic chemicals in various forms and causes adverse effects on beneficial soil micro flora / micro fauna, plants, animals and human beings. Various microbes present in soil act as the scavengers of these harmful chemicals in soil. The pesticides/chemicals reaching the soil are acted upon by several physical, chemical and biological forces exerted by microbes in the soil and they are degraded into non-toxic substances and thereby minimize the damage caused by the pesticides to the ecosystem. For example, bacterial genera like Pseudomonas, Clostridium, Bacillus, Thiobacillus, Achromobacter etc. and fungal genera like Trichoderma, Penicillium, Aspergillus, Rhizopus, and Fusarium play important role in the degradation of the toxic chemicals / pesticides in soil.

Biodegradation of hydrocarbons: Natural hydrocarbons in soil like waxes, paraffins, oils etc are degraded by fungi, bacteria and actinomycetes. E.g. ethane (C2 H6) is metabolized and degraded by Mycobacteria, Nocardia, Streptomyces Pseudomonas, Flavobacterium and several fungi.

There are four major tracts where salt affected soils are commonly met within India. These are:

1. The Semi-arid Indo-Gangetic alluvial tracts (mainly in Punjab, Haryana, Uttar Pradesh and a part of Bihar)
2. The arid tracts of Rajasthan and Gujarat.
3. The arid and semi arid tracts of southern states, particularly of the irrigated rigor (Vertisols) soils.
4. The coastal alluvium

Earlier it was estimated that about 7 million hectares of land have been affected by salinity/sodicity conditions in India. The area under these soils increased and reached to the level 10 million hectares at present.

Chemistry of vegetable crops

Vegetables play an important role in human nutrition supplying some of the materials, which other food materials are lacking. Vegetables are important in neutralizing the acidity formed during digestion. They also serve as roughages in human nutrition and thus helping digestion.

They are the important sources of minerals like Ca, P and Fe. They also form an important source of vitamins, especially vitamin A. Green and yellow vegetables like carrot, turnip, spinach, beans, etc. contain appreciable amounts of vitamin A. Direct seed of beans, peas, and legumes contain appreciable amounts of proteins. Vegetables also contain sufficient amounts of vitamin C and also appreciable quantities of thiamine, niacin and folic acid. Tomatoes and potatoes contain fairly high amounts of vitamin C.

Leaf analysis and its importance

Improved fertilizer management for crops is important in view of today’s need to reduce production costs, conserve natural resources, and minimize possible negative environmental impacts. These goals can be achieved through optimum management of the fertilizer applied. Understanding the crop nutrient requirements and using soil testing to predict fertilizer needs are keys to fertilizer management efficiency.

Plant tissue testing is another tool for use in achieving a high degree of precision in fertilizer management. Timely tissue testing can help diagnose suspected nutrient problems or can simply assist in learning more about fertilizer management efficiency. Leaf analysis (also called stem leaf analysis, tissue analysis or foliar analysis) is the most precise method of monitoring plant nutrient levels. While soil analysis reveals the levels of essential soil nutrients, leaf analysis shows the grower exactly what the plant has successfully absorbed. Leaf analysis is especially helpful in detecting nutrient deficiencies before they affect plant health and yield.

The crop growth and productivity is conditioned by many factors of which, the nutrient status (Content) of plant parts such as leaf, stem, etc play a critical role. Moreover the leaf and stem are considered as the indicator parts of plants for assessing the nutrients content of plant. Each crop plant requires the essential element at a specific concentration at different growth stages and it is known as ‘critical level’. When the nutrient content of plant depletes below the critical level the plants may exhibit some symptoms. The requirement or otherwise the availability of nutrients can be assessed by i) plant diagnosis ii) soil analysis and iii) plant analysis by two methods a) by qualitative test and b) by quantitative estimation. Based on the plant or soil tests, the required nutrients can be applied for crops to sustain the growth and rectify the deficiency disorders. The rapid tissue test would pave way for rectifying the nutritional problems for quick recovery, however the quantitative estimation of both plant and soil for nutrients concentration will be more useful and economic for applying fertilizers either as basal or foliar and would be the long term strategy to cope up with nutritional problems.

For rapid tissue test to assess the nutrient status, different parts of plant should be taken as indicator tissue and some of the representative crops are furnished below:

Introduction

It is necessary to ascertain the quality of irrigation water so as to gauge the possible effects of this water on the soil. The irrigation water often results in water logging, salinity and alkalinity problems. It is therefore very important to know its quality. Following are the basic criteria or characteristics on which irrigation water quality is judged.

1. Presence of total soluble salts in irrigation water.
2. Proportion of carbonates and bicarbonates in relation to calcium and magnesium in irrigation water.
3. Proportion of sodium in relation to other cations in irrigation water.
4. Concentration of specific ions in irrigation water.

Several parameters are employed to judge the quality of irrigation waters No parameter in complete in judging the quality of irrigation water. Further the quality of water should be judged by considering the crop and soil factors. Any judgment without considering the above factors may not be useful. Researchers devised many parameters by following above said criteria. Some of the commonly adopted parameters used to judge the quality of irrigation water are:

Introduction

In classification of irrigation water, it is assumed that the water will be used for average conditions with respect to soil texture, infiltration rate, drainage, quantity of water used, climate and salt tolerance of the crop. Large deviations from the average for one or more of these variables may make it unsafe to use what, under average conditions, would be a good water; or may make it safe to use what, under average conditions, would be a water of doubtful quality. The relationship to average conditions must be kept in mind in connection with the use of any general method for the classification of irrigation water.

However, the quality of irrigation water is evaluated, mainly by the quantity of dissolved salts, proportion of anions, monovalent and divalent cations, sodium adsorption ratio, residual sodium carbonate, potential salinity, specific ion toxicity, proportion of magnesium, calcium in water etc.

Soil pollution is any physical or chemical change in soil that adversely affects the health of plants and other organisms living in and on it.

Soil pollution is important not only in its own right but because so many soil pollutants tend to move into surface water, groundwater, or air.

The chief soil pollutants are salts, petroleum products, heavy metals, and agricultural chemicals. Point source releases of industrial solvents (both LNAPLs and DNAPLs) and feedstock chemicals (e.g., for making plastics) often occur as the result of LUSTs (leaking underground storage tanks).

Salinization, a common problem in irrigated arid and semiarid regions, makes soil unfit for growing most crops. It is extremely difficult to remove excess salts from salinized soils.

A variety of techniques are used for soil remediation, which is cleaning up contaminated soil.

1. These include physical techniques such as
   1. Soil vapor extraction (SVE), moving air through the soil.
   2. Thermal conduction heating, heating the soil before SVE.
2. Bioremediation methods include
   1. Landfarming, fertilizing, liming, and repeatedly plowing contaminated soil to stimulate bacterial decomposition of high molecular weight hydrocarbons like those in diesel oil.
   2. Bioventing, pumping air at low rates through soil to provided O₂.
   3. Biosparging, pumping air into aquifers to provided O₂.
   4. Phytoremediation, particularly useful for removing heavy metals.

1. Introduction

The remains of almond, found in several archeological sites, show the importance of this crop since centuries. Being storable after drying, the fruits can be transported everywhere, this is the reason why, these nutritious nuts have followed the human migration. The easy adaptability of this species to poor soils has favored their spread. It is an elixir for good health and a panacea for all ills. Almonds have long been an integral part of India’s cultural heritage, especially during festive seasons and weddings. In an increasingly health-conscious nation like India, the demand for almonds is ever increasing. However, several problems plague production and limit output which has led to high import.

1.1. Nutritional value

Almonds are good source of fat, in which 80% is in the form of monounsaturated fatty acids (MUFA) which decreases unwanted cholesterol of body. Almonds contain omega-6 fatty acid which is good for heart. The amount of saturated fat is very less in almonds. Almonds have high amount of phosphorus and calcium which is required for bone growth. Magnesium, manganese, vitamin B6 and Vit. E are also available in almonds. Almond oil contains glucosides, minerals, vitamins and is rich in protein. Nutritive value of almond has been presented in Table1.

1. Introduction

The cultivated apple (Malus × domestica Borkh.), is the most important fruit in temperate regions of the world. Apples were frequently used in different mythologies as symbols of immortality or reincarnation. One of the most popular stories attached to apple is that of Adam and Eve, who ate the forbidden fruit from the tree of good and evil which was in the center of the garden of Eden. The Latin word Malus has two meaning i.e. apple and evil, which has probably stemmed from this story from bible. In Greek mythology, mother earth or Gaia, presented a tree with golden apples to Zeus and his bride Hera on their wedding day. These golden apples were later indicated with many stories of love, bribery and temptation ranging from the abduction of Helen of Troy to the defeat and marriage of Atlanta. Goddess Pomona was deity of fruit trees in Rome. In many cultures, garden of paradise and pleasure is symbolized as the place with fruit-laden apple trees. Apple is popular because of its delicious taste and pleasant aroma.

1. Introduction

Apricot is among the highly nutritious fruits of Rosaceae family and appreciated for its health promoting contents. Studies have shown that apricot fruit is effective in preventing stomach ulcers and oxidative damages of living systems (Enomoto et al., 2010; Miyazawa et al., 2006). Apricot tree belongs to genus Prunus in the Rosaceae (rose) family. Apricot (Prunus armeniaca) is categorized under ‘stone fruits’, along with peaches, plums, almonds, and some cherries, due to its seed being enclosed in a hard, ‘stone’ like endocarp. This fruit is native to temperate Asia, first discovered growing wild on the mountain slopes of China, and long cultivated in Armenia later.

Throughout its history, apricot has been noted for delicious flavor, delicate velvety fruit surface, and early flowering and fruiting. The name apricot is a corruption of the Arabic and Greek al-paraecox which means the early fruit. The old spelling ‘apricock’ is retained in English until the 17^th century. The fruits are mainly consumed fresh but are also cooked and often stuffed. The high sugar content makes them suitable for drying. In china they were also preserved by salting and smoking. Other uses include fruit leathers, nectars, and liquors (Janick, 2005).

1. Introduction

Cherry is the common name of several Prunus species that include sweet cherry (P. avium), tart or sour cherry (P. cerasus), Duke cherry (hybrids between P. avium and P. cerasus). Sweet cherries are believed to have originated from the area between the Black and Caspian seas of Asia Minor. Birds probably carried the seed to Europe prior to human civilization. Cultivation was probably started by the Greeks and continued by the Romans. Its distribution and naturalization have proved extensive, for it is now found wild in areas as widely spaced as northern India, the southern plains of Europe and even on isolated islands such as Madeira. Climatic conditions are the most important limitations on cherry production. Being a deciduous tree, it needs a period of dormancy, which is initiated in temperate regions mainly by a fall in average temperatures in late autumn (Mir et al., 2017). Sweet cherry is grown almost everywhere in the temperate zone. It is a composite genus. Due to its origin, this genus needs warm and light conditions, but can also endure cold winter weather. It requires 550-600 mm precipitation annually. Sweet cherry prefers medium light (pH= 5.5–7.5), deep-layered soil, which is rich in nutrients. The root system of sweet cherry requires aeration and cannot tolerate slack water (Simon, 2004). Many areas of the world, although environmentally suited to cherry production, are currently unsuited to profitable cherry production due to high perishable nature of the fruit.

1. Introduction

Hazel nut also called as European filbert or Bhotia badam (Corylus avellana L.). Apparently the word ‘filbert’ has been derived from Middle English which in turn was a derivation of Philbert - the Saint Philibert, whose feast day in late August coincides with the ripening of the nut. Others believe that the term filbert came from the nut’s long husk being referred to as a full beard in Old English. The name “Hazel” comes from the Anglo-Saxon word for bonnet, “Haesel”; this probably derives from the greek “korys” (as in Corylus), for helmet or hood. The term “filbert” may have derived from “full beard”, descriptive of the long, leafy husk. The scientific name avellana derives from the town of Avella initially and was selected by Linnaeus from Leonhart Fuchs’s De historia stirpium commentarii insignes (1542), where the species was described as “Avellana nux sylvestris” (“wild nut of Avella”). Hazelnut is the 4^th economically important nut crop (748,000 MT/yr) of world after cashew, almond and walnut.

1. Introduction

Kiwifruit (Actinidia deliciosa Chev.) is among the most recently domesticated of all fruit plants. The kiwifruit of international commerce are large – fruited selections of Actinidia deliciosa Planch and Actinidia deliciosa (A. Chev.) C F Liang et A. R. Ferguson, belongs to family Acitinidiaceae. A. chinensis has been cultivated commercially for little more than 20 years, however, A. deliciosa for about 70 years. This is known as “China’s miracle fruit” and “Horticulture wonder of New Zealand”. Although this fruit vine originated in China, yet its full economic potential was exploited by the New Zealanders, which accounts for over 70 per cent of world trade (Franco, 1990). Kiwifruit has completely replaced the older name of ‘Chinese gooseberry’. In China, ‘Mihoutao’ (monkey peach) is used for all Actinidia species, but as A. chinensis and A. deliciosa are by far the most important economically of the various Actinidia species in China, they are often simply referred to together as Mithoutao. More explicitly, the two species are sometimes referred to together as Zhonghua (Chinese) Mihoutao. In other countries of the world, its cultivation gained momentum after 1960s and now is cultivated on a commercial scale in USA, Italy China, Japan, France, Germany and Australia.

In India, it was first introduced in 1960 at Lalbagh garden, Bangalore, but the plant did not come into bearing due to lack of chilling requirement during winter for its bud break. Later on, in 1963, it was introduced in Shimla hills, where the plant came into bearing in 1969. In order to assess the performance of kiwifruit cultivation in different agro-climatic conditions of state its plantation were done at different locations. After evaluation, this fruit was recommended for commercial cultivation in mid and low hills of the state. It can also be grown in mid hill of Jammu and Kashmir, Uttrakhand, Sikkim, Arunachal Pradesh, Meghalaya, Nagaland and Nilgiri hills of south India.

1. Introduction

Olive (Olea eurpaea L.) is an evergreen species commonly grown in the Mediterranean basin. The oil extracted from the fruit is a predominant component of the ‘Mediterranean diet’, which has documented heart- and cancer-protective benefits. These derive from the lipid composition and from biologically active molecules that accumulate during olive fruit development. The oil can reach up to 30% of the total fruit fresh weight at full ripening and is highly present in the mesocarp and at lower levels in seeds. Oil increase reaches a plateau in pulp after varaison. A marked triacylglycerol accumulation in seed and pulp occurs after endocarp lignification, when about 40 mg of oil per fruit per week can be synthesized. The fatty acid profile of the oil accumulating in the fruit is important in relation to its nutritional properties. The main fatty acid is oleic acid (C18:1), which represents about 75% of total fatty acids, followed by linoleic (C18:2), palmitic (C16:0), stearic (C18:0) and linolenic (C18:3) acids (Martinelli and Dandekar, 2014).

The olive, Olea europaea L, is the only species of the botanical family Oleaceae with edible fruit. The tree blooms with small white flowers in May, and fruit set begins almost immediately afterward in May or June. Ripening is complete toward the end of November or December, depending on the variety. Its cultivation began more than 6000 years ago in the Middle East, and spread west on both sides of the Mediterranean Sea.

1. Introduction

The peach [Prunus persica (L.) Batsch] is an important fruit crop of temperate regions, all over the world. Important centers of commercial production usually lie between latitudes 30° and 45° North and South. At higher latitudes, minimum winter temperatures and spring frosts are the limiting factors. The peach flower bud is hardy and can tolerate minimum temperature of about -23 to -26° C. Its northern range is extended where minimum temperature are ameliorated by large bodies of water, as western continental seaboards, the great Lakes in the U.S.A. and Canada and the Caspian and Black seas of Eurasia. Mid continental areas are characterized by lower winter temperatures and usually more severe spring frost hazards. Most peach cultivars require 500 to 1000 chill hours below 7.2° C to foliate and bloom. At lower altitudes, the winter requirement is not met. The peach with its smooth skin mutant is known as nectarine. Nectarines can be used in the same way as peaches, and may be considered as substitutes for peaches.

1. Introduction

Pear is among the oldest of the world’s fruit crops, figuring in both Bible and the tales of Homer. They are by far the most important of the deciduous tree fruits, are widely grown in temperate and increasingly, in tropical regions, and figure prominently in world trade. The fruit is primarily grown for the fresh fruit market, which is much more remunerative than that for processing.

Pear (Pyrus communis, Rosaceaea family), is a deciduous fruit, grown under a wide variety of climatic regimes, ranging from cold dry temperature hilly conditions to warm humid subtropical conditions. It is grown in many places of India like Jammu and Kashmir, Himachal Pradesh, Karnataka, Tamil Nadu, Kerala, Utter Pradesh. Sandy pear plants were brought to Amritsar by travellers from China who settled at Harsha Chinna village near Amritsar about 2,500 years ago. The Kashmir valley represents one of the major Pear (Pyrus communis.L.) growing areas of the world. Pear was introduced in India from China. The time at which Pear was introduced to Kashmir is not precisely known, however Yukteshwar Kumar writes in his book “A History of SinoIndian Relations” that peach and pear came to India during the early years of the Eastern Han period (25 AD to 220 AD). This pre historic fruit has been under cultivation both in Europe and Asia for about 3000 years (Hedrick et al., 1921). Between 16^th and 18^th centuries, many European writers travelling Kashmir noted fantastic royal gardens of the Mughals, mentioning the abundance of peach, pear, plum and cherry trees, with fountains spouting cold, icy water. Pear (Pyrus communis. L), originating from the German word ‘peer’ meaning fruit, is a fascinating fruit steeped in rich history. This fruit is known as ‘tang’ in Kashmiri language. Low chill requiring pears are being cultivated in plains of North India. Cultivars requiring high chilling hours (900-1000) are cultivated at higher hills of Jammu and Kashmir, Himachal Pradesh and Uttarakhand. Majority of the Pear production is actually limited to Kashmir however, low chilling cultivars grow in subtropical regions.

1. Introduction

Pecans (Carya illinoensis) are one of the most desirable trees to plant in home yards. Their size and natural beauty as a shade tree and its capacity to produce a nutritious food make them valuable. Pecan is the most widely cultivated and the most economically important member of the North American hickory group. Beyond its native range, pecan is commercially grown from the southeastern USA to the south-west (California) (Hanna, 1987, Peterson, 1990, Harlow et al., 1991). Pecan is from an Algonquian word, meaning ‘a nut requiring a stone to crack’. In Mexico, pecans and walnuts share the same Spanish name, neuz, which is a cognate of the English word nut. In the USA, pecan is considered the queen of nuts because of its value both as a wild and as a cultivated nut and acceptable quality of meats (Woodroof, 1979). Pecan is also considered as ‘queens of nuts’ because of its value both a wild and as a cultivated nut and acceptable quality of meats. As compared with other nut fruits which have been grown since time immemorial, pecan has been under cultivation only for about one hundred years but has gained enormous popularity.

1. Introduction

The pistachio nut tree, Pistacia vera L. has been extensively cultivated since ancient times in the Middle Eastern and Mediterranean countries; in India, Afghanistan. The climatic conditions favorable to pistachio culture are similar to those for almond and olives, and prevail in extensive regions of the western United States also. Pistachio is a nut which comes originally from Iran and has the history of 4000 to 5000 years. Pistachio is a drought-tolerant, slow-growing, deciduous tree that reaches to a height of 30 ft. The tree survives in arid regions where summers are hot and the winters cold. Rocky, poor terrain with little rainfall is no problem as long as there is good drainage. The fruits grow in clusters. Although called a nut, botanically, pistachios are actually drupe. The pistachio consists of a bone ivory shell that encases the edible meat portion, called the seed.

1. Introduction

Plum is one of the important stone fruit crops of temperate region throughout the world. The Japanese group of plum is native to China but was domesticated in Japan and subsequently was introduced to different parts of the world. In India, Japanese plums were introduced by European settlers and missionaries around 1870. Plum grows well in areas ranging from 900 m to 1600 m above mean sea level.

1.1. Uses

Among deciduous fruits, plum is widely distributed in the world, because of wider adaptability among different species and cultivars of plum to varied agro-climates and soil conditions. Plum is consumed as dessert, dried and processed products. Plum fruit is considered best to overcome the jaundice. Its fruit use for a preparation of juice and squash. It ranks next to peach in commercial production. It is widely cultivated in several countries in Europe, Asia and in the America.

1. Introduction

Quince is a highly nutritious underutilized fruit of sub-Himalayan region which has great economics and medicinal potential and it belongs to the group of the oldest cultural plants. Quince is known with different names, Urdu name ‘Bahee Dana’, Farsi name ‘Beh’, Greek name ‘Strythion’, Kashmiri name ‘Bamchunth’ and Hindi name ‘Bihi’ (Torkelson, 1995, Khoubnasabjafari and Jouyban, 2011). Quince is very much like pear in shape and gets a golden yellowish outer layer when mature. Quince fruit is a valuable dietary product and even then it less suitable for the direct consumption (Hricovsky et al., 2003) and for that reason they are mostly used either cooked (Alvarenga et al., 2008) or preserved (Kyzlink, 1990). However, as compared with other species, this fruit tree species is less popular throughout the world. Its predisposition to turning brown and decay is a limiting factor in the long-term storage of this fruit (Gunes, 2008). The nutritional value of the fruit is high (Bucsek et al., 1996; Kopec and Balik 2008). It is well known that quince fruit shows antioxidant effects (Silva et al., 2002) which result from the presence of a number of polyphenolic substances (Fattouch et al., 2007), e.g. flavonoids quercetin, rutin, kaemp ferol etc. (Silva et al., 2005), and also from increased levels of vitamin C (Tetera, 2006). Quince has the important nutritional and flavor composition more than many fruits. Vitamin C content of quince is nearly two times higher than in apple (Biro and Lindner, 1999).

1. Introduction

The modern cultivated strawberry (Fragaria x ananassa Duch.) is one of the most delicious, refreshing and soft fruits of the world. Worldwide it is also the most widely distributed fruit-crop due to its genotypic diversity, highly heterozygous nature and broad range of environmental adaptation. The plant is cherished in gardens and in commercial fields for its beautiful red fruit that has a tentalizing aroma (Sharma, 2002; Sharma and Sharma, 2004). Being a rich source of vitamins and minerals coupled with delicate flavour, strawberry has now become an important table-fruit of millions of people around the globe. It is amongst the few fruit crops, which gives quicker and very high returns per unit area on capital investment, as the crop is ready for harvesting within 6 months of planting. However, due to several technological advances in its cultivation like, introduction of day-neutral cultivars, and protected cultivation, strawberries remain available as fresh fruit throughout the year.

At present, strawberry is grown in wide climatic zones, extending to temperate, Mediterranean, sub-tropical and taiga zones (Sharma, 2002; Sharma and Sharma, 2004). Its cultivation is influenced by the specific regional adaptations due to critical photoperiods and temperature requirements and thus its cultural systems are highly variable. Due to the constant efforts of strawberry breeders, the world-wide interest for strawberry cultivation has boosted its production tremendously, which has resulted in widespread popularity of strawberry in the last 50 years.

1. Introduction

Persian walnut is of great importance across worldwide where nuts are harvested from wild stands, backyard gardens and rarely from commercial orchards that vary considerably in their size due to degree of management. The walnut is an old tree cultivated before the Greek age and appreciated for centuries for its fruits, wood and other parts utilized in several ways. Before the discovery of the phenomena of allelopathy, someone considered the walnut an un-healthful tree, since peasants used to wake up with migraine or fever after they had slept under a walnut tree. Some others considered the walnut a cursed tree, and in fact in Italy an old walnut tree growing in Benevento, has long been considered the place where the witches used to dance during the night of Saint John and, therefore, that tree was named “Tree of the Witches” (Avanzato, 2010).

Nuts are collected for home consumption, sale at local roadside stands and markets and for shipping to cities. Walnut trees are further utilized for their high quality timber to make a wide array of products. The leaves, bark and other plant parts are used for medicinal remedies and trees are grown and maintained for soil conservation purposes (Mamadjanov, 2006b). A diverse mix of seedlings, local selections, and advanced cultivars are grown for nut production, many with unknown origins, including some of which are the direct result of selection from the wild.

In domestic animals, skeleton (Fig. 1-1) is a framework that is formed of bones, cartilages and ligaments binding together giving the specific shape, form and support to the body. In addition, the skeletal framework surrounds the major cavities of the body giving protection to other soft visceral organs of the body. There are three major parts of skeleton in the animal body (1) the axial skeleton (2) the appendicular skeleton and (3) the splanchnic skeleton.

The axial skeleton consists of the skull, vertebral column, ribs, and sternum. The appendicular skeleton consists of the bones of fore limb and hind limb

The splanchnic skeleton includes some of the bones embedded in the substance of visceral organs in the body such as os cordis in ox and os penis in dog.

Bones

The bones forming the skeleton of the body are of different shape, size, form and the constituting tissue material. The number of different types of bones of any species may differ in various stages of the growth of the animal. So also the numbers of various bones differ from species to species.

A branch of anatomy that deals with joints or articulations in the body is termed as arthrology or syndesmology. A joint is an articulation or union formed by two or more bones or cartilages with the help of connective tissue. To form a joint, the long bones meet at their extremities e.g. joints of fore limb and hind limb. Joints of flat bones are formed by their borders or edges e.g. joint of bones of skull, the cranial and facial bones. The short bones and irregular bones form a joint by uniting at any of their parts or surfaces e.g. intervertebral joints.

Classification of joints

Joints are classified on the basis of their structure i.e. the kind of tissue material by which the bones are united, the other constituent parts that help in uniting the bones and the kind of movement performed at that joint. On this basis, the following three major types of joints exist in the skeleton of animal body.

A branch of anatomy that deals with muscles and their accessory structures is called as myology and the body system concerned with myology is called muscular system. The muscular system is composed of specialized cells called muscle fibres because of their shape in the form of fibre or spindle. The plasma of these cells contains myofibrils which are contractile elements that cause contraction of muscles in a definite manner under the influence of a stimulus which is a unique property of muscles. These cells together constitute the distinctive muscular tissue.

Classification of muscles

Based on their morphological and functional characteristics, there are three types of muscles in the body.

Smooth muscle: The muscular tissue in this type of muscles is constituted by masses of spindle shaped cells and they occur mainly in the walls of hollow visceral organs including glands, the vessels, eye ball and hair follicles. These are nonstriated muscles. Contraction in these muscles is weak but sustained and mostly consistent and rhythmic. The action of this muscle is involuntary i.e. not under the will.

Cardiac muscle: The muscle fibres of this muscle are arranged in irregular masses and they form cross striations. The ends of some fibres come in contact with the sides of others forming a kind of syncytium. This is a striated muscle and its action is involuntary. This muscle occurs only in the wall of the heart and the immediate proximal ends of the major blood vessels like aorta, venacava and the pulmonary veins.

The digestive system consists of organs concerned with prehension and digestion of food, absorption of digested food and expulsion of unabsorbed food. The digestive system extends from lips to the anus and consists of the primary and accessory organs of digestion. The primary organs include the mouth, pharynx and the alimentary canal (gastrointestinal tube) in that order of sequence. The accessory organs include the tongue, teeth, salivary glands, liver and pancreas. The alimentary canal extends from pharynx to anus and consists of the oesophagus, the stomach, the small intestine and the large intestine. The wall of the alimentary canal consists of, from within outward, the mucous membrane, the muscular layer and the serous layer forming the visceral peritoneum.

Mouth

The mouth is bounded dorsally (roof) by hard palate and behind that the soft palate, ventrally by the body of the mandible along with the mylohyoideus muscles and laterally by the cheeks. The entrance of the mouth cavity is bounded by the lips and it is called as rima oris, while its caudal opening into the pharynx is called as aditus pharyngis. The cavity of the mouth (cavum oris) is subdivided into two parts by the teeth and alveolar processes (the alveoli) of the mandible. The inner part i.e. the space within the teeth and alveoli is termed as mouth cavity proper, while the space between the cheeks and lips and the teeth and alveoli is called the vestibule of the mouth. The mucous membrane of the mouth cavity is continuous with the margin of the lips and the common integument and caudally it continues with the mucous membrane of the pharynx.

The respiratory system is a complex biological system comprised of several organs that facilitate the inhalation of oxygen and exhalation of carbon dioxide (breathing) in living organisms. The major functions of the respiratory system is providing oxygen to the body cells and removing carbon dioxide from the body. In addition to this, the respiratory system helps in controlling body temperature (especially in dogs), eliminating water (as vapour) and assisting in voice production. The organs of respiratory system extend from nose to lungs. These consist of two major parts, the upper respiratory tract and the lower respiratory tract. The upper respiratory tract is comprised of nose, nasal cavity, the part of mouth, and the part of pharynx. The lower respiratory tract is comprised of the larynx, trachea, bronchi and lungs.

Nose

The nose is the externally visible part of the respiratory system. It forms the part of the face of the animal extending from the transverse level of eyes to the rostral end of the head. Exteriorly it is formed by the bones, muscles, cartilages and the skin. Internally it encloses the nasal cavity which is lined by the mucous membrane. The dorsal part of the nose (roof of the nasal cavity) is termed as dorsum nasi. It is formed by the nasal and frontal bones of the skull. The lateral parts are formed by the incisive, maxillary, lacrimal and zygomatic bones. Covering these bones externally is a muscular layer formed by the facial muscles running over these bones and acting on the upper lip and nostrils. The muscular layer is externally covered by the skin. The skin on the nose bears fine hairs except at the tip of the nose that is formed by the nostrils. The rostral end of the nose is formed by nostrils which provide entrance to the nasal cavity. The nostrils are supported by cartilages which are the dorsal and ventral extensions of the cartilage of the nasal septum. The main aim of the nose is to support and protect the nasal cavity.

Urinary system is relatively simple and consists of a pair of kidneys, a pair of ureters, the bladder and the urethra. The kidneys are the main organs that filter the blood and produce the urine while the rests of the organs of this system are simply accessory structures that are used for transport and storage of urine. For proper functioning of the metabolic processes of the body, it is essential to constantly maintain the chemical composition and volume of the tissue fluid. This is called the homeostasis. This particular task is performed by the urinary system and in particular by the kidneys.

Kidneys

The kidneys right and left, are bean shaped red brown relatively large glands situated in the abdominal cavity. These are placed retroperitoneal against the dorsal wall of the abdomen on either side of the spine. The right kidney is about half of its length ahead of the left kidney and it fits into the renal impression on the caudate lobe of the liver. An indentation at about the middle of the medial border is the hilus of the kidney through which pass the renal vessels, nerves and ureters. Both the kidneys are covered by a thin capsule formed of fibrous tissue which surrounds the parenchyma of the kidneys. The capsule can be easily striped away from the kidney. The function of the kidneys is to maintain the volume and composition of the plasma,regulate water, ion, and pH levels, retain nutrients and excrete fluid wastes, toxins and excess electrolytes. The kidneys achieve these functions through glomerular filtration, solute reabsorption, tubular secretion, water balance and acid-base regulation.

The renal capsule provides a stiff outer shell to maintain the shape and protect the inner soft parenchyma. Deep to the capsule is the soft, dense vascular cortex. Several cone shaped pyramids form the medulla deep to the cortex. The pyramids are aligned with their bases facing outward towards the cortex and their apices point inward towards the centre of the kidney. Each apex connects to a minor calyx, a small hollow tube that collects urine. The minor calyces merge to form three major calyces, which further merge to form the hollow renal pelvis at the centre of the kidney. The urine collected into the pelvis drains into the ureter that exits through the hilus of the kidney.

Reproduction is the physiological process by which organisms produce offspring. Sexual reproduction involves production of gametes. The gametes are produced by the gonads. The rest of the process of converting the gametes into the offspring involves other reproductive organs. The male and female animals have different genital organs that contribute to reproduction. The organs of reproduction (genital organs) in male include a pair of male gonads the testes (sing.-testis), the epididymis, ductus deferens, the seminal vesicles, a prostate gland, a pair of bulbourethral glands (Cowper’s glands), the male urethra, and the penis. In female the genital organs include a pair of gonads the ovaries, the fallopian tubes, the uterus, the vagina, the vulva and the mammary glands.

Male genital system

The overall function of the male genital organs is to continuously produce and store the male gametes the sperms, to maintain the continuous supply of semen, to detect estrus in female, and to inseminate and fertilize the female gametes. While the testes are the site for production of sperms, the epididymis, vas deferens and the accessory glands like prostate, seminal vesicles, and bulbourethral glands are responsible for the production of different secretions which mix together and are known as seminal plasma or seminal fluid. The seminal fluid provides a source of energy, buffers, antioxidants and other compounds needed for sperm survivability, maturation and motility. Once spermatozoa are mixed with the seminal fluid, the combined product is called the semen.

Pituitary gland

The pituitary gland (hypophysis) lies at the base of the skull and is housed within a bony structure called the sella turcica in the body of the basisphenoid bone. It is a small pea shaped gland which is attached to the hypothalamus by the pituitary stalk. The pituitary gland has two distinct parts called the lobes. These are the anterior lobe (adenohypophysis) and the posterior lobe (neurohypophysis). The anterior lobe which is also called as anterior pituitary consists of five types of cells, each of which secretes different hormone or hormones. The types of cells, the hormones secreted by each type and the functions performed by them are narrated below.

Heart

The heart is a cone shaped thick walled and four chambered muscular organ. It lies obliquely craniocaudal in the middle mediastinum in between the left and right lungs and is covered by pericardium inside the thoracic cavity. The major part of heart (about 60 per cent) lies to the left of the middle mediastinum. The broad upper end is the base of the heart. It lies at the junction of the dorsal and middle third of the dorsoventral diameter of thorax at the level of about third to sixth rib and it faces craniodorsally. The narrow lower end is the apex. It lies just dorsal to the sternum at the level of about sixth rib and it faces caudoventrally. The surfaces, right and left are convex. They meet cranially at the right ventricular border and caudally at the left ventricular border. The right (cranial) border is strongly convex. It runs ventrally and caudally. The greater part of this border lies parallel to the sternum. The left (caudal) border is much shorter and nearly vertical. The surfaces of the heart are marked by grooves which indicate the division of the heart into four chambers the two atria dorsally and the two ventricles ventrally. The atria are separated internally by the interatrial septum. The ventricles are separated by interventricular septum. The circular coronary groove indicates the division of the heart in to atria dorsally and ventricles ventrally. It encircles the heart in its upper third part except at the level of the origin of pulmonary artery. The coronary groove is quite deep and wide. It provides passage for the coronary artery and vein. Apart from these, it is deeply filled with fat. The right (subsinuosal) interventricular groove and left (paraconal) interventricular groove indicates the line of separation between the two (right and left) ventricles by the interventricular septum. Both of these grooves run downward from the coronary groove towards the apex parallel to the respective borders and terminate just above the apex. The right and left ventricular grooves are occupied by the respective coronary vessels along with the fat.

The great vessels that leave and enter the chambers of the heart include the Aorta, the Pulmonary Artery and the Pulmonary Veins.

Aorta

The Aorta is the main systemic arterial trunk. It begins as ascending aorta at the base of the left ventricle, passes craniad and dorsad between the pulmonary artery on the left and the right atrium on the right and then turns caudad inclining slightly to the left, thus describing a curve called the aortic arch with its convexity directed upward and forward and the concavity facing downward and backward. From here it proceeds caudad on the ventrolateral surface of the thoracic vertebrae and the longus colli muscle as the descending aorta. At its origin from the base of left ventricle, the caliber of the aorta is greatest forming the bulbus aorta and here it presents three dilatations called the aortic sinuses. As the descending aorta reaches the level of the seventh thoracic vertebra it continues behind as thoracic aorta running through the middle and caudal mediastinum between the left and right lungs. The thoracic aorta first lies to the left of the median plane and then gradually inclines inwards medially and becomes median in position when it reaches to the diaphragm. It then passes through the hiatus aorticus of the diaphragm and enter the abdominal cavity as abdominal aorta. From here it passes caudad below the bodies of the lumbar vertebrae and the psoas major muscle. After reaching at the level of the sixth lumbar vertebra, the abdominal aorta terminates in the iliac quadrification by dividing into two external and two internal iliac arteries.

The lymphatic system is a part of circulatory system and a vital part of the body’s immune system. It is comprised of lymph vessels, lymph ducts, and lymph nodes that move the lymph from tissues to the blood stream and the organs such as the spleen, thymus and bone marrow that produce the lymphocytes and white blood cells. Lymph is very similar to blood plasma. During circulation through the body, the blood reaches to the capillaries at the interstitial spaces. The plasma of the blood is filtered through the capillary wall. The fresh oxygen along with nutrients, hormones and other necessary fluid matters from this plasma are released in to the interstitial fluid and about 85 per cent of the plasma along with the carbon dioxide and metabolic wastes, return into the circulation through the capillary walls. The remaining 15 per cent of the plasma along with the debris of other waste products and the lymphocytes constitutes the lymph which is returned to the circulation through an accessory route of lymphatic vessels and lymph nodes constituting the lymphatic system.

Lymph Vessels: The lymph vessels start as finger-like blind ending thin walled lymph capillaries in the interstitial connective tissue. These capillaries form a network and drain into the thicker walled collecting lymph vessels, lymph ducts and lymphatic trunks. Finally the larger lymph trunks and ducts empty their content the lymph into the cranial vena cava at the thoracic inlet. The lymph vessels contain numerous valves with one or two leaflets preventing the back flow of lymph through the lymph vessels. During its course in a centripetal direction through the lymph vessel, the lymph of each lymph vessel has to pass through at least one lymph node prior to its entry into the blood circulation. As a result there lies a chain of lymph nodes on the pathway of lymph vessels in the body.