eChapters

INTRODUCTION

Heterosis has contributed significantly towards increased crop production and it has become the basis of multibillion dollar agro-businesses in the world (Phillips, 1999). Hybridization is the important way that can create genetic variability and make new options. The F1 population is obtained from the crossing of two homozygous but genetically dissimilar gametes or individuals (purelines in self pollinated crops or inbred lines in cross pollinated crops) that shows increased or decreased vigour over the better or mid parent value. Heterosis is maximum in F1, generation which diminishes gradually in later generations. Hence, production of F₁, hybrid seeds of different flower crops is considered as the extreme focused area in floriculture industry.

Hybrid vigour is used as a synonymous of heterosis. In 1910, the term heterosis was first used by Shull who defined this phenomenon as the stimulus of heterozygous, and in his word, it has been the “interpretation of increased vigour, size, fruitfulness, speed of development, resistance to insect-pests and diseases or to the climatic rigors of any kind manifested by the out breeding organism as compared with corresponding inbreds as a specific result of the unlikeliness in the constitution of uniting parental gametes”. This definition is often interpreted as not implying a genetic basis for heterosis, because the definition basically describes the phenotypes that result from the crossing of two different inbred lines. Generally, heterosis is manifested as an increase in vigour, size, growth rate, yield, or some other characteristics but in some cases, the hybrid may be inferior to the weaker parent. This also represents as heterosis (average heterosis), and if heterosis is estimated over the superior parent, such an estimate is sometimes referred to as heterobeltiosis, hence, authors feel “heterosis refers a biological phenomenon in which the F₁ population obtained by crossing of the two genetically dissimilar gametes or individual shows increased or decreased vigour over better parent or over the mid-parental value. Earlier, Power (1944)also suggested that the term heterosis should be used only when the hybrid is either superior or inferior to both the parents. Other situation should be regarded as partial or complete dominance. It can be easily explained with the help of Table 5.1.

Heterosis, hybrid vigor, or outbreeding enhancement, is the improved or increased function of any biological quality in a hybrid offspring. The adjective derived from heterosis is heterotic.Heterosis is the occurrence of a superior offspring from mixing the genetic contributions of its parents. These effects can be due to Mendelian or non-Mendelian inheritance.

The commercial exploitation of heterosis started only after the rediscovery of Mendel’s law of inheritance and consequent understanding of the theoretical basis of hybrid vigour. Heterosis is considered as a major revolution in classical plant breeding era. Utilization of heterosis has substantial influence in genetics to provide hybrid vigour, consequently high yielding hybrids in different crops and plants. Yield increase from heterotic hybrids due to the expression of heterosis is up to 30% superior to conventional varieties. The term heterosis was first used by Shull (1914) and represents the increase or decrease in fitness and vigour of the F₁ hybrid over the mean or mid parent values, produced by crossing two genetically different individuals for one or more traits. Generally, positive heterosis is desirable but in some cases like maturity duration and presence of toxic substances, negative heterosis is condiderable as desirable. Heterosis can be estimated in three different ways. When the heterosis is estimated over mid parent, it is called as relative heterosis or mid parent heterosis. Estimation of heterosis over better parent out of the two parents involved in the cross is referred as “Heterobeltiosis”, the term which was coined by Fonseca and Patterson (1968). “Standard Heterosis”, often called as useful heterosis which was coined by Meredith and Bridge (1972) and denotes the superiority of F₁ over the standard commercial check.

Definition: Heterosis is defined as the percent increase in the performance of outbred animals over the average of their parents.
The mean superiority of hybrids over the average of their parental lines is called heterosis. Heterosis or hybrid vigor is the increased vigor of the offspring over that of the parents when unrelated individuals are mated. Hybrid vigor includes greater viability, faster growth rate, greater milk production and greater wool production in domestic animals. The amount by which the hybrids exceed the mean performance of better parent is called heterobeltiosis or Euheterosis. The term heterosis was coined by G.H. Shull (1914). Heterosis or hybrid vigour is synonym to each other. However, the heterosis is a phenomena exhibited by an individual or a group of individuals due to heterozygosity of genes. Heterosis in quantitative terms can also be defined as the non-additive gene action. While “hybrid vigour” is the resultant of heterosis phenomena expressed phenotypically by an increase in vigour, size, production, reproduction, survival rate, growth, and economic returns etc. the heterosis is a measure of extent magnitude of out breeding.
In livestock, hybrids may be produced by crossing between two species/breeds/ lines/strains. Technically, heterosis may be positive or negative. However, the desirability of a trait is more important than the sign of heterosis. In some cases, the negative heterosis could be a desirable one (e.g. age at first lay, age at first calving, calving interval, back fat thickness etc.). The amount of heterosis obtained usually depends upon the extent of heterozygosity attained by the hybrids, which in turn is based on the diversity of sire and dam lines crossed. It also depends upon the degree of dominance, over dominance and/ or for which the heterosis is exhibited. Thus, the main causes of heterosis are directional dominance, over dominance and epistasis.

Hybrid vigor or heterosis is opposite and complementary to inbreeding depression (reduction in fitness as a direct result of inbreeding). In theory, the heterosis observed after crossing is expected to be equal to the depression upon inbreeding, considering a large number of crosses between lines derived from a single base population. In practice, plant breeders are interested in heterosis expressed by specific crosses between selected parents, or between populations that have no known common recent origin. Furthermore, because heterosis is subject to the interactions between genotype and environment, it is desirable to describe the heterosis of a particular hybrid line for a specific trait at a specific location or under specified environmental conditions.

This alternative pathway for glucose oxidation has enzymes in the cytosol through which glucose is degraded to carbon dioxide. It is also called a shunt because carbon atoms from glucose 6-phosphate take a long route before they proceed down the EMP or glycolytic pathway. This pathway is anabolic in nature as it produces many intermediates. In this pathway, two NADPH are generated from one glucose 6-phosphate molecule. No ATP is generated or consumed.
Overall, this pathway needs three glucose-6-phosphate molecules to complete all the reactions. Therefore, one cycle run produces 2 mol of fructose-6- phosphate, 1 mol of glyceraldehyde-3-phosphate, and 3 mol of carbon dioxide from 3 mol of glucose-6-phosphate with the reduction of 6 mol of NADP+ to NADPH.
Overall reactions of the HMP pathway are as follows:
3 Glucose-6-P + 6 NADP+→ 3 ribulose-5-P + 3 CO2 + 6 NADPH
3 Ribulose-5-P → 2 xylulose-5-P + Ribose-5-P
2 Xylulose-5-P + Ribose-5-P → 2 fructose-6-P + Glyceraldehyde-3-P

Introduction

Flowers speak millions of unspoken words. Presenting a bouquet and making arrangements with flowers in most of the drawing rooms, offices, hotels and hospitals have become the style of the day in the fast – moving modern world where there is hardly any time for exchange of sweet memories. Since time immemorial, the importance of such a delicate creation of nature has always been appreciated. Tamil Nadu ranks first among the flower producing states of India, contributing 25% of the country’s flower production with an area of 31, 970 ha under flowers. Of this, around 700 ha are under protected cut flower cultivation. In Nilgiri district alone, it has an area of around 70 ha under protected cut flower production which is inclusive of around 11.2 ha of lilium.

The genus Lilium (Lilium spp.) is a herbaceous flowering plant normally grown from bulbs, about 110 species world over belongs to lily family Liliaceae. It is native of the northern temperate regions. The species in this genus are the true lilies while the other plants with lily in the common name are related to the other groups of plants. Lilies are usually erect leafy stemmed herbs. The majority of species form tunicless scaly underground bulbs from which they produce flowers. The large flowers have three petals along with three sepals, look like petals.

1. INTRODUCTION

Today’s technological advancement have reached a level where a farmer can have access to information and tools to manage his mechanized field operations. They can now measure, evaluate and deal variability with infield (e.g. soil fertility, water availability and yield) that was known to exist previously but was not manageable, to his advantage. The ability to handle variations in productivity within a field and maximize financial return, reduce waste and minimize impact on the environment has always been the objective of an enterprising farmer, especially those with limited land resources and those who advocate sound agriculture practice.

This concept is not new. What is new is the ability to automate data collection and documentation and the utilisation of this information for strategic farm management decision in the field operations through mechanisation, sensing and communication technology. Such an approach in agriculture production management gives rise to what is now termed as Precision Farming (PF), Precision Agriculture (PA), Prescription Farming (Precision farming), Site Specific Agriculture (SSA), Soil Specific Crop Management (SSCM), Spatially Variable Crop Production (SVCP) etc.

• It is the technology of intensive production system.
• In which modern, less environmental dependent and capital–intensive but with a capacity to improve productivity and farmer income.
• Use of plastics, protected cultivation, precision farming, high density planting (HDP), integrated nutrient management (INM), integrated pest management (IPM), mechanization etc., are important facets of hi-tech horticulture. There are many practices which helps to enhance horticulture production:

Introduction to Hi-Tech Horticulture Greenhouse area in different countries

1. Japan - 42,000 (ha)
2. Holland - 10,000 (ha) 3) Italy - 20,000 (ha)
3. USA - 4,000 (ha)
4. India - 700 (ha)
   • Crops are grown in the greenhouse Strawberry, grapes, citrus, banana, papaya, melons.
   • Salt affected soils in different states: UP - 2,375 °
     • Gujarat - 1,334
     • W.B. - 1,150
     • RJ - 458
     • Punjab - 749 Haryana - 636

Introduction

Rose, acclaimed as the “Queen of Flowers”, is one of the most popular cut flowers in the global floriculture trade. Popularly referred to as ‘Dutch rose’ in the international market, cut rose occupies a prominent place among the cut flowers owing to its exquisite form, size and attractive colours. Apart from cut flower it is used for making various value added products such as rose oil, rose water, garland, gulkhand, rose attar etc and also in landscaping as pot plant and garden plant. The present day rose (Rosa hybrida) combines all desirable qualities such as, productivity, attractiveness of buds, a variety of colours and forms of the typical species of Rosa.

The major cut rose producing countries of the world are the Netherlands, Colombia, Kenya, Israel, Italy, United States, and Japan. In India, roses are mostly grown under cover (poly house) in Nasik, Pune, Hosur, Kalimpong, Darjeeling, Bangalore, Solan, Palampur, Shimla, Srinagar, Delhi, Ludhiana and Calcutta. The roses grown for export should be popular varieties of that region and maintain high quality standards with respect to bud size and stem length and should have lush green leaves and be free of pests and diseases. These high quality standards can be achieved and maintained only when grown inside poly house or greenhouse, which gives protection against inclement weather conditions and pests and diseases.

Malvaceae, the mallow family, carries herbs, shrubs or trees comprising about 75 genera and perhaps as many as 1,500 species. Hibiscus and Abelmoschus are two important genuses under this plant family. Several species of plants of potential uses come under these two genera about which limited publications are available. 

Hibiscus

Hibiscus is a large genus of about 200-220 species of flowering plants in  Malvaceae, native to warm temperate, subtropical and tropical regions throughout the world. The genus includes both annual and perennial herbaceous plants and woody shrubs and small trees. The leaves are alternate, simple, ovate to lanceolate, often with a toothed or lobed margin. The flowers are large, conspicuous, trumpet-shaped, with five petals, ranging from white to pink, red, purple or yellow, and from 4-15 cm broad. The fruit is a dry five-lobed capsule, containing several seeds in each lobe, which are released when the capsule splits open at maturity.

Abstract: Ornamental hibiscus (shoe flower) is native of Asia, probably China, but now conspicuous in all warm countries. Hibiscus is cross pollinating, evergreen shrub and progeny can segregate widely for traits due to heterozygosity. High polyploid constitution of species predominant vegetative reproduction and rampant hybridization irrespective of chromosome number are features of this crop. The important traits for continuous crop improvement include plant with good growth habit, floriferous nature, desirable flower colour, size, shape and good keeping quality. A variety of flower forms, flower colours and growth forms exist. Very little genetic information and trait heritability has been established for this crop. Use of somatic hybridization, mutation breeding and marker assisted breeding are discussed. The continuous use of these techniques will ensure creation of new phenotypes for the market.

Hibiscus a well known member of the family Malvaceae, grows as an evergreen shrub plant. The plant is extensively cultivated as an ornamental plant that bears large flowers on the bushy hedges. These enormous flowers are usually dark red in colour and are not usually fragrant. The huge size and the reddish colour and hues attract humming birds (Kumar and Singh, 2012). The generic name is derived from the Greek word “hibiskos” which was the name Pedanius Dioscorides gave to Althaea officinalis. Hibiscus rosa-sinensis was named by Carolus Linnaeus. The Latin term “rosa-sinensis” literally means “rose of China”, though it is not closely related to the true roses. Member species are often noted for their showy flowers and are commonly known simply as hibiscus, or less widely known as rose mallow. The hibiscus is used as an offering to goddess Kali and Lord Ganesha in Hindu worship. Hibiscus is an important flowering and garden plant. It has various medicinal values (Chopra et al., 1996 and Sayed et al., 2012).

ORIGIN AND DISTRIBUTION

The ancestors of the modern exotic hibiscus were originally native to Mauritius, Madagascar, Fiji, Hawaii, China and India. Ornamentally most important species is Hibiscus rosa-sinensis. There is no known record of the history of the domestication of Hibiscus rosa-sinensis. In one view it is believed that the species is a native to China and was first cultivated by the Chinese for its showy flowers (Kimbrough, 1997). No extant wild populations of the species have however, been reported from that country. Another view holds that the species is a native of the South Indian Ocean islands of which Madagascar, the Mascarene Islands and the Rodriguez Islands are a part (Borssum Waalkes, 1966). This view is strengthened by the fact that three Hibiscus species genetically compatible with H. rosa-sinensis are native to this area (Singh and Khoshoo, 1989). It is thought that the species was collected and domesticated on these islands by far easterner during their westward migration.

Hibiscus a well known member of the family Malvaceae, grows as an evergreen shrub plant. The plant is extensively cultivated as an ornamental plant that bears large flowers on the bushy hedges. These enormous flowers are usually dark red in colour and are not usually fragrant. The huge size and the reddish colour and hues attract humming birds (Kumar and Singh, 2012). The generic name is derived from the Greek word “hibiskos” which was the name Pedanius Dioscorides gave to Althaea officinalis. Hibiscus rosa-sinensis was named by Carolus Linnaeus. The Latin term “rosa-sinensis” literally means “rose of China”, though it is not closely related to the true roses. Member species are often noted for their showy flowers and are commonly known simply as hibiscus, or less widely known as rose mallow. The hibiscus is used as an offering to goddess Kali and Lord Ganesha in Hindu worship. Hibiscus is an important flowering and garden plant. It has various medicinal values (Chopra et al., 1996 and Sayed et al., 2012).

Hibiscus (Hibiscus rosa-sinensis) is a vigorous tropical evergreen flowering shrub valued for its large, colourful and attractive blooms. In India, its flowers are widely used for religious offerings, particularly in temple worship, as well as for ornamental and loose flower purposes. The chapter introduces its origin, distribution, genetics, botanical characteristics and important varieties. It also highlights the crop’s medicinal and food-related importance, including the use of hibiscus products in herbal beverages and processed foods. Detailed production practices cover climate, soil, propagation, field preparation, nutrient management, irrigation and cultural operations. Major pests and diseases, harvesting, postharvest management and yield are also included for commercial cultivation.

Hides and skin are the important and widely used animal by-products of slaughter house industry. Human beings are utilizing animal skins since time immorial and nomadic people still depend upon them for shelter, clothing, weapons, food containers etc. In general on live weight basis yield of hide is 7 percent while skin is around 11 percent.  Though it is also obtained from the fallen animals but the superior quality hide is always of slaughtered animals. Source wise slaughtered animals account 20-25 percent of hide and 80 percent of skin whereas fallen animals contributes around 75-80 percent of hide and 20 percent of skin. So the major sources for hide are fallen animals and skin is from slaughtered animals.

Classification involves grouping organisms into a series of hierarchical categories. Actual method of establishing a classification consists in defining groups or categories on a hierarchical scale. The animals can be classified in a taxonomic hierarchy consisting of a series of categories of ascending ranks from species to kingdom. Each of these categories includes one or more groups from the next lower level. Therefore, all animals can be classified in a taxonomic hierarchy consisting a series of categories in ascending order from species to kingdom such as species, genus, family, order, class, phylum and kingdom.

According to the history of biological classification, Aristotle, a Greek philosopher classified different animals based on the habitat, characteristics etc. Later Swedish botanist Carolus Linnaeus introduced taxonomic hierarchy categories during 18th century and this system is followed globally.

Taxonomic hierarchy refers to the sequence of categories in increasing or decreasing order. Kingdom is the highest rank and species is the lowest rank in hierarchy. Taxonomic hierarchy is the process of arranging various organisms into successive levels of biological classification. Each of the level of the hierarchy is called taxonomic category or rank.

Abstract

High altitudes may be cold and humid or cold or arid ones making the requirements of protected cultivation entirely different in both the conditions. The present chapter is based on the environmental conditions existing in Leh region. Near sub-zero temperature with snow in higher altitudes makes vegetable production tough without use of techniques of protected cultivation. Protected cultivation has witnessed gradual developments from riverbed cultivation practices to use of several types of plastics (PP, PE, PVC etc.) and UV stabilized polythene sheets. Area under protected cultivation is spread worldwide mainly in countries like Holland, Spain, Isaral, China , Japan etc. Protected cultivation technology provides favorable climate for production of vegetable &/or their seedlings of superior quality even in the extreme adverse climate outside. Such structure exploits solar thermal energy to improve photosynthetic efficiency of the plants grown inside. This green house effect is very helpful in winters at high altitudes. Similarly, some modifications in these structures are needed to low the temperature during summers. A number of advantages with some limitations can be listed that are associated with the protected cultivation. At high altitudes, three methods viz. Polyhouse/Greenhouse /Net /shaded house, Low tunnels or row covers and plastic mulching can be used. Polyhouse is a framed structure with 200 micron UV stabilized low density cladding forming a greenhouse effect. Underground trench type polyhouse can also be made with polyethylene supported on wooden poles or GI pipes. Though a combination of above two known as polyench was found performing better in Ladhak area. Low tunnels or row cover use transparent plastic films or net over low hoops to cover rows of plants. Mulching is covering the soil around plants to conserve soil moisture, temperature, preventing weeds etc. using transparent and black plastics of 10-25micron thickness. Double colored plastic mulches are being tested for different crops and different seasons. In arid high altitudes, DRDO (through DIHAR, Leh) has worked extensively on protected cultivation and developed production technologies in the service of nation. Its contribution includes making possible the production of nursery, cucurbits and several other vegetables and their seeds in sub zero climatic conditions. Now, there is a need to develop more area specific, more appropriate, efficient and economic protection structures. Simultaneous development of tools, machinery and vegetable varieties suitable for use in protected conditions are among the major aspects of future work to be done in this field.