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Dry Flower Products

Dry flowers are aesthetically beautiful and they enhance the décor and liveliness of any room. They bring the fiery warmth and bounty of the season into the home with ease every fall. Much of fall’s beauty lies in the glorious changing colors of autumn leaves. These flowers are dried to use them in a wide range of products. Dried floral products are widely used for decoration and for adding zest to a room. Apart from that they are also used as an essential component of many products. They are widely used to make handmade paper, lampshades, candle holders, jute bags, photo frames, boxes, books, wall quilts, topiary, cards and several gifts. The use of dry flowers in the making of these products enhances the appearance and beauty of these products. They look sophisticated when gifted to someone or used as a décor of your own home.

23.1 Dry Flower Packing

Careful packing is one of the most important aspects of any product. Dry flower packing is the simplest way to capture the essence of summer flowers till long. Dry flowers should be packed nicely to avoid any damage. They should be packed alone in appropriate sized carton loosely cushioned with paper.They should be packed in a manner to keep them away from direct sunlight leaving some room for air. Packing material should be stable and firm to hold the dry flowers well without any damage during storage or transportation. Dry flowers can be packed in a variety of ways: in poly bags, window box, cardboard box, or in a sachet.

Driftwood is wood that has been washed onto a shore or beach of a sea or river by the action of winds, tides, waves or man. It is a form of marine debris or tide wrack.

In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides shelter and food for birds, fish and other aquatic species as it floats in the ocean. Gribbles, shipworm sand bacteria decompose the wood and gradually turn it into nutrients that are reintroduced to the food web. Sometimes, the partially decomposed wood washes ashore, where it also shelters birds, plants, and other species. Driftwood can become the foundation for sand dunes.

Preserving plant materials in a dried form is not a new idea. It has been considered as an art for hundreds of years. Fragrant dried herbs were placed in Egyptian pyramids. Dry flower arrangements have been popular in Europe for several centuries. During 1700 A.D, the early American settlers used dry flowers to brighten their homes. Any plant material can be preserved for use as dry flowers (Al Pertuit, 2004). Though enormous work is being done in this field, most of the literature is published by horticulture amateurs. Scientific work in this area is less. However, a review of the research work done in dry flower technology is discussed in detail.

World Trade Organisation

The World Trade Organisation (WTO) was the result of years of painstaking efforts on the part of governments and other bodies to establish a globally acceptable basis for a new economic order. It was established to correct the imbalances and disparities in international trade and bring about an evenly balanced world trade order that equally benefits the developed, developing and least developed nations. While there are several agreements under the WTO, the Agreement on Trade Related Aspects of Intellectual Property Rights (TRIPS Agreement) specifically represents the resolve of all member countries to use intellectual property as one of the means for achieving economic balance and diminishing the trade barriers.

Growth of horticulture is the cornerstone for augmenting employment opportunities in agriculture sector both directly and indirectly. Of late, there is a marked shift in the cropping pattern towards diversification into high value commercial crops in the country. To make horticulture viable and profitable, the thrust should be on improving the resource use efficiency, so that the relative profitability could be enhanced. Success in horticulture is more technology driven compared to other crops. The time bound removal of quantitative curbs on imports and other barriers to access domestic market under WTO, of which India is a signatory, will require Indian Horticultural produce / products to become competitive both in the domestic and international markets. This would call for use of Hi-tech horticulture technologies. The term Hi-Tech Horticulture was coined in recent years. There are no standard definitions for this. The Department of Agriculture and Co-operation,GOI in 1999 defined Hi-tech Horticulture as “any technology which is modern, less environment dependent, capital intensive and has the capacity to improve the productivity and quality of horticultural crops”.

In the backdrop of a predominantly agrarian economy, India has made tremendous advances in modern agriculture to meet both the food and nutritional security. In recent years, horticulture has assumed great importance mainly to augment nutritional security and secondarily as a highly cost-effective, remunerative and eco-friendly enterprise having vast export potential. To meet the challenges of research and development, tracer techniques have added the much needed fillip as they can be ingeniously applied to resolve issues which are not ordinarily possible using conventional techniques.

Horticultural crops are ideal and valuable assets of nature to mankind. They are popular among masses since time immemorial but their importance was realized only in the recent past due to their high nutritive value, good taste and pleasing quality. They provide essential nutrients and minerals for proper functioning of human body and aesthetic surroundings for peaceful living. India is an important centre of diversity and several horticultural crops  originated here.  The horticultural crops constitute 13.08% of total crop area and contribute about 28% to GDP. The sub-continent extends from 8° 04’ - 37° 06’ North latitude and 68° 07’- 97° 25’ East longitude and it has tropical, sub-tropical and temperate climates which favour successful growing of a large number of horticultural crops.  India has a wide variety of climate and soil on which a large number of horticultural crops like fruits, vegetables, potato and other tropical tuber crops, ornamentals, medicinal and aromatic plants, plantation crops, spices, cashew and cocoa are grown. Of late, major emphasis was laid on development of high yielding varieties and high production technologies and their adoption in areas of assured irrigation paved the way towards food security.

Vegetables are the most extensively utilized plants for  exploitation of heterosis for  development of hybrids. As the importance of heterosis breeding increased, male sterility proved an asset particularly in crops like onion and carrot which produce many but small sized flowers making hand emasculation tedious. Large scale hybrid seed production sometimes remains handicapped because of high labour cost, unavailability of trained labour at crucial times i.e. at blooming, bad weather conditions like continuous rains etc. The phenomenon of male sterility has always been of long term interest for  researchers of various disciplines of applied, strategic and basic sciences. It is of special interest for  plant breeders to produce more efficient and economic hybrid seed. Discovery of certain male sterile mutants which  eliminate more laborious operations of emasculation combined with various marker genes further facilitate identification of undesirable types even at seedling stage has widened the very basis of hybrid seed production. This technique has also reduced the total cost of hybrid seed production. Onion crop provides one of the rare examples of very early recognition of male sterility (Jones and Emsweller 1936), its inheritance and use in hybrid seed production (Jones and Clarke 1943). Since then male sterility is reported in fairly large number of crops including vegetables.

Polyembryony is the occurrence of more than one embryo in a seed. It includes all those instances in which there is a clear indication of the actual occurrence of two or more embryos in a developing ovule (Tisserat et al. 1979). The additional embryos in polyembryony result from the differentiation and development of various maternal and zygotic tissues associated with the ovule of seed. Earlier, polyembryony is said to have an abnormal feature but now it is considered as a desirable character in citrus, mango, jamun, almond, etc. to obtain true to type planting materials. The polyembryony is one of the apomictic processes which have been described to occur in the ovules of angiospermic species (Koltunow, 1993). Polyembryony in horticultural crops occurs as facultative apomixis wherein simultaneous growth of multiple embryos of somatic origin co-exist in the same seed containing sexual embryo resulting from either selfing or cross pollination.

Food irradiation involves exposure of food to short wave energy to achieve specific purposes like extension in shelf life, insect disinfestations and elimination of food-borne pathogens and parasites. Compared to heat or chemical treatment, irradiation is more effective and an appropriate technology to destroy food-borne pathogens without much loss to the quality of food. It offers a number of advantages to producers, processors, retailers and consumers. Irradiation is a cold process and can be used to pasteurize and sterilize foods without affecting freshness and texture of food. Unlike chemical fumigants, irradiation does not leave any harmful toxic residues in food and is more effective. It is efficient and can be used to treat prepacked commodities. The FAO estimates that about 25% of world’s total food production is lost due to insects, bacteria and rodents after harvesting. Use of radiation can play an important role in cutting these losses and reducing dependence on chemical pesticides. The food borne diseases claim millions of lives all over the world every year. Irradiation of food can reduce these incidences by destroying harmful microorganisms.

Plant diseases are mentioned in some of the oldest books available (Homer, C – 1000 B.C. mentioned about the therapeutic properties of sulphur and in Old testament – 750 B.C.) and were feared as much as human diseases and war.

The history of plant breeding is divided into 4 periods- knowledge of plant breeding before 1900, application of genetic principles (1900-1940), plant breeding research after 1940 and the recent developments in plant breeding. Emphasis is given on the land marks in genetic improvement of vegetable crops.

The major land marks  in genetics and breeding of crop plants are listed below.

India is a vast country with varied soil and agro-climatic conditions and therefore is able to grow a wide range of vegetables. In view of their productivity, diversification, nutrition, value addition and export, vegetables are an important component in Indian agriculture. Up to 1939, vegetable seeds were used to be imported from Australia, U.K., U.S.A., but after World War I and II, India started seed production of vegetables. In the recent past, the seed industry has made rapid strides over the past three decades and has contributed significantly to the quantum jump in agricultural production and India emerged as the second largest producer of vegetables, next to China in the world. During 2005-2006, India produced 113.5 million t of vegetables from 7.2 million ha with a productivity of 15.76 t/ha. The seed industry has increased certified and quality seed production and distribution by the organized sector to about 60 lakh quintal from 300q in 1964-65. India can be proud of having launched and managed both crop improvement and seed improvement as simultaneous and parallel programmes playing complimentary and synergistic roles.

Plant Growth Promoting Rhizobacteria (PGPR) are free-living bacteria  having beneficial effect on plants by root colonization. They stimulate plant’s growth. Intensive research work is carried out on use of various PGPR as plant growth promoters on various crops. There are reports which show that PGPR promoted growth and reproductive parameters of cereals, pulses, ornamentals, vegetable crops, plantation crops and even  tree species. The important PGPR used in vegetable crops are Azospirillum, Azotobactor, Pseudomonas fluorescens, Phosphate Solubilising Bacteria (PSB) and Bacillus subtilis.

The term DNA sequencing refers to methods for determining the order of the nucleotide bases, adenine, guanine, thymine and cytosine, in a molecule of DNA. In molecular terms ,the definitive understanding of a DNA molecule comes from determining its nucleotide sequence.The function of a gene can be deduced from its nucleotide sequence,for example by comparing the sequences of genes with known functions.

The first DNA sequences were obtained by academic researchers, using laborious methods based on 2 – dimensional chromatography in the early 1970s.  Following the development of dye-based sequencing methods with automated analysis, DNA sequencing has become easier and orders of magnitude faster.  Knowledge of DNA sequences of genes and other parts of the genome of organisms have become indispensable for basic research studying biological processes, as well as in applied field like diagnostic or forensic research.  The advent of DNA sequencing has significantly accelerated biological research and discovery.

Use of morphological markers has continued till today for characterization of several crops including horticultural crops with the Mendel’s principles of inheritance by following visible traits in the progenies of sexual crosses. Genetic markers play an essential role  in the study of variability and diversity, in the construction of linkage maps, and in the diagnosis of individuals or lines carrying certain linked genes. Within this context, the limitations of morphological markers became quickly apparent. They tend to be restricted to relatively a few traits, display a low degree of polymorphism, are often environmentally variable in their manifestation, and can depend on the expression of several unlinked genes. Furthermore, some may affect plant viability or seed set, distorting gene frequencies in the progeny. Morphological markers were largely supplemented by biochemical markers, particularly isoenzymes that could be easily scored by electrophoresis (Ganapathy and Scandalios 1973; Tanksley 1983). The limitations of isoenzmyes as markers, in particular both the limited number of polymorphic enzymes that can be conveniently stained and the environmental effects on expression pattern, were apparent already twenty years ago (Tanksley 1983).

Ethylene is a primary plant hormone involved in the senescence of plant tissues including flowers and leaves. In carnation flowers, inhibition of the synthesis or action of ethylene delays the onset of senescence symptoms and lengthens the vase life of flowers. Leaves of cut chrysanthemum of some cultivars frequently become yellow, sometimes prior to the onset of flower senescence, in response to exogenous ethylene. Generation of transgenic plants with suppressed production or action of ethylene is an excellent way to lengthen the longevity of these ornamental plants. This paper reviews our studies on generation and characterization of carnations with reduced ethylene production and chrysanthemum with reduced sensitivity to ethylene.

Root and Tuber crops are the most important food crops of man after cereals. Tuber crops are efficient producers of carbohydrates especially under suboptimal conditions of rainfall, fertility and low input conditions encountered in tropics. The group contributes about 6 % of the world’s dietary calories. In fact, one out of 6 kg of human food comes from roots and tubers. Tuber crops find an important place in the dietary habits of small and marginal farmers especially contributing to food security of tribal populations. Tuber crops grown in India include Cassava, Sweet potato, Dioscorea, Colocasia, Amorphophallus and minor tuber crops like Chinese potato, Arrowroot, Canna, Yam bean etc. The biotechnology can contribute to the solution of the major problems and realize greater benefits for tuber crops.

California’s Napa Valley, situated at the northern end of the San Francisco Bay 30 miles (48 kilometers [km]) from the Pacific Ocean, is the most famous wine appellation in the United States. This small valley, 56 km long and 8 km wide at its broadest point, has produced some of North America’s finest wine grapes from the 1850s to the present. Today it contains approximately 18,616 hectares [ha] of vineyards along the valley floor, in the foothills and mountains flanking the main valley and in the smaller valleys in the eastern part of Napa County [45].

The term Geographical Indications (GIs) attained significant status in trade agreement negotiations after the establishment of World Trade Organization (WTO).Under WTO, Agreement on the Trade Related aspects of Intellectual Property Rights (TRIPs) sets forth standards to regulate international intellectual property protection and enforcement and establishes international minimum standards for GIs. Geographical Indications identify goods that have a specific geographical origin and possess a quality, reputation or other characteristics which are due to that place of origin. Geographical Indications are now widely accepted as valuable marketing tools in the global economy and are useful to protect rights of communities. Geographical Indications are not granted to individuals but are granted to the group/association of producers as the symbol of collective ownership.

Biology, the science of living organisms, is linked with microscopes, test tubes and Petri dishes, but these conventional methods are changing with the advent of Bioinformatics. Due to the advancement in molecular biology and genome sequencing techniques, there is an overflow of biological information. This flood of information has led to a requirement for computerized databases to store and organize the data and to design specialized computational tools to view and analyze the data. Accordingly Bioinformatics can be defined as conceptualizing biology in terms of macromolecules (in the sense of physical-chemistry) and then applying “informatics” techniques (derived from disciplines such as applied maths, computer science and statistics) to understand and organize the information associated with these molecules on a large-scale (Tramontano, 2007).

Very little is known about the basic principles governing the chemistry of flavour or fragrance. In English, the term aroma chemicals is used for both fragrance and flavour compounds. Any compound with a sufficiently high vapour pressure will have an odour and this is normally of the molecular weight of around 300, a relatively low polarity granted (Frater et al., 1998). Generally only compounds with pleasant smell are considered to fall under the realm of fragrance chemistry, but purified individual components from a mixture may have a malodour. Almost all ancient civilizations had their tradition of making fragrances from natural materials, mostly of plant origin, but also of animal origin – these are mostly essential oils, exudates, balsam and resins (Arctander, 1969).
 
It was in the latter half of the 19th century that synthetic fragrance chemicals were experimented upon and brought into the market, examples being coumarin (Fig. 1) (in the year 1866), salicylaldehyde (Fig. 2) (1876), vanillin (Fig. 3) (1876), phenylacetaldehyde (Fig. 4) (1883), piperonal (Fig. 5) (1890), musk xylol (Fig. 6) (1891) and b-ionone (Fig. 8) (1893) (Frater et al., 1998).

Reasons for serious concern for food security in developing countries are, increasing food demand for the rapidly growing population, decline in productivity in high productive areas due to ‘Green revolution’ fatigue, and increasing vulnerability of agriculture to potential climate change. Climate scientists predict that global warming will make arable land in many developing countries less productive or unusable. Of all the parameters, abiotic environmental stresses contribute significantly to reduction in potential yield (Flowers and Yeo, 1995). Abiotic stresses arise from extremes of climate. The stress factors especially drought and salinity negatively effect plant growth and development, salt stress being one of the most serious environmental factors limiting productivity of crop plants (Ashraf, 1999). Therefore, extensive research into plant salt tolerance was carried out, with the aim of improving resistance of crop plants. With a large majority of the world’s population relying on crops like barley, maize and rice to survive, crop salt tolerance is globally important.

In general terms, dormancy can be defined as a period during the biological cycle of the plant in which growth of the whole organism (seed) or a plant organ (bud, tuber, corm etc.) is suspended eventhough the environmental conditions for growth may be favourable. More specifically, dormancy refers to a condition in which growth is inhibited by a restriction of essential metabolic processes, such as water uptake, gas exchange and cell division, either as a result of endogenous dormancy-controlling factors or in response to exogenous factors such as changes in the environment. It is distinct from a transient state of quiescence or rest imposed by an unfavourable environment in that dormancy persists even when the environment becomes favourable for growth whereas quiescence ceases.

For wild plants, dormancy has evolved as a means of enabling the plant to endure periods of stress due to drought or low temperatures and is therefore critical for the survival of the species. In cultivated arable or vegetable crops, breeding has generally led to a loss of dormancy or a reduction in the length of the dormant period. In arboreal crops of temperate climates, however, bud dormancy is still an essential feature of the annual growth cycle of the tree.

India produces 9.2% of world’s vegetables and fruits, nearly 109 million tons of vegetables and 57.69 million tons of fruits. The production of horticultural commodities is expected to grow to 300 million tons in near future (Kaur, 2008). India accounts for 18.2% of global trade in vegetables and 0.5% in fruits. The overall food wastages are very high amounting to around Rs. 10.4 lakh million. India wastes more fruits and vegetables than what U.K consumes. It is estimated that cumulative wastage of fruits and vegetables, on the farm, during procurement, storage and at the retail outlets, is worth about Rs.422250 million. 

Grafting is a horticultural technique. It is used commercially for many woody plants and some herbaceous plants. The purposes of grafting include asexual propagation, obtaining resistance to soil borne diseases, nematodes and unfavorable conditions, and improving fruit quality. Although there are advantages to grafting, graft incompatibility often prevents its practical use. Graft incompatibility occurs when the combination of scion and rootstock is inappropriate. The enormous range of genotype varieties used in grafting results in a wide range of physiological, biochemical and anatomical interactions between graft partners. Therefore, the causes and mechanisms of graft incompatibility vary according to graft combinations. Garner (1979) defined graft incompatibility as the failure to unite into a strong union, the failure to grow in a healthy manner, or premature death, when such failures could be attributed to differences between rootstock and scion.
 
The purpose of this review is to understand graft incompatibility as an aid to solving graft incompatibility problems. The symptoms and types of graft incompatibility are described, the causes and mechanisms of graft incompatibility are explored, and directions for future research are identified.

Micronutrients play an active role in the plant metabolic processes from cell wall development to respiration, photosynthesis, chlorophyll formation, enzyme activity, hormone synthesis, nitrogen fixation, etc. Micronutrient requirements of crops are relatively small. Use of chemical fertilizers with accompanied changes in soil management practices resulted in steady decrease in micronutrient content in soil. The future of agriculture depends on sustainable management of land, water, flora, fauna and the atmosphere. In order to produce 240 m tones of food grains by the end of twentieth century, removal of major nutrients from soil will be to the tune of 7 m tones N, 2.7 m tones P2O5 and 11.2 m tones K2O. Similarly, a good amount of secondary (Ca, Mg, S) and micronutrients would also be removed proportionately which should be compensated through application of well rotten FYM or micronutrient fertilizers in soil.

Bioinformatics encompases the use of tools and techniques from three separate disciplines; molecular biology (the source of the data to be analyzed), computer science (supplies the hardware for running analysis and the networks to communicate the results), and the data analysis algorithms, which strictly define bioinformatics. So the list below incorporates events from these areas into a brief history of the field.

Entomology, a Greek word entomoV, entomos, “ that is cut in pieces or engraved/segmented”, hence “insect”; and -logia, logia -study, is the scientific study of insects , a branch of arthropodology. The arthropods made their appearance during the earliest Devonian period while humans appeared only in Quarternary. Insects possess an immense degree of evolutionary maturity as against man, account for more than two-thirds of all known organisms, date back some 400 million years, and have many kinds of interactions with humans and other forms of life on earth. Entomology is a speciality within the field of biology and it is rooted in all human cultures from prehistoric times.

In India, insects were known from Vedic era and records of insects in India were evident from India’s mythological epics, the Ramayana and Mahabharatha. 

Horticultural crops play an important role in Indian agricultural economy. Though only 2.4% of cultivated area is under these crops, they contribute about 21% to the Agricultural GDP. Though horticultural crops contribute more for the national economy, its contribution could be further increased by minimizing 30% loss of horticultural crops due to pests and diseases. Continuous and unrestricted use have dictated the need for development of ecologically safer pest management technologies. Among the non-chemical methods, resistant varieties, cultural practices, plant derivatives and biocontrol agents are important and these methods can be integrated successfully. In recent years, interest among regulatory authorities, agricultural advisors and growers has forced to seek for alternative solution of plant disease management. It has encouraged intensive research of microbial products as agents for plant disease management. This resulted in commercialization of a number of microbial biocontrol products.

India is predominantly an agriculture based country and 65% of the Indians depend on agriculture. To meet the ever increasing nutritional demands of Indian population, production and productivity of vegetables have to be increased manifold within the limited available land and other resources. Seed is the basic and critical input in which the expected dividends from all other inputs depend and it plays a crucial role for enhancing the stability of productivity. With the ever increasing demands for a mechanized, energy efficient type of agriculture, each seed is expected to produce a vigorous plant, which would develop. uniformly under a wide range of environmental conditions.

Seed enhancement technologies have historical basis dating back hundreds to thousands of years. Seed coating was being practiced by ancient Chinese farmers who coated seeds of rice with mud balls to anchor the seeds in water saturated soil . The Greeks presoaked the cucumber seeds in milk or water to make them germinate quicker. Keeping the seeds in moist cloth or soaking in water prior to sowing was a common practice among the farmers of India from time immemorial.

Fruits are living commodities which continue to respire and transpire even after harvest. The storage life of fresh fruits is indirectly proportional to the rate of their respiration which in turn depends on the atmospheric gas composition in which they are stored. Normal air contains about 20.9% oxygen (O2), 78.0% Nitrogen (N₂) and 0.03% carbondioxide (CO₂). Lower levels of O₂ and higher levels of CO₂ in the storage environment result in reduced rate of respiration, delayed ripening and increased storage life. The reduction in O₂ concentration and increase in CO₂ concentration in the storage room with precise control and maintenance of these gases throughout the storage period is generally referred as controlled atmosphere (CA) storage.

CA storage is generally used for long term storage or long distance transportation of fruits in combination with low temperature storage. The use of CA storage for extending the post harvest life of fruits has increased steadily worldwide during the past 60 years. This trend is expected to continue with the advancement of technologies in attaining and maintaining CA during transport, storage and marketing of fresh fruits.

Fruit ripening is a highly coordinated, genetically programmed and an irreversible phenomenon involving a series of physiological, biochemical and organoleptic changes which finally lead to the development of a soft edible ripe fruit with desirable quality attributes. Ripening is the process where changes take place in the fleshy fruit and make it edible. It represents the unique coordination of developmental and biochemical pathways leading to changes in colour, texture, aroma and nutritional quality of mature seed-bearing plant organs (Barry and Giovannoni, 2007). Physiologically mature fruit is transformed from an unfavourable state of firmness, texture, colour, flavour and aroma to favourable state for consumption. It is the final phase in the development of fruit and involves major metabolic changes and it is normally an irreversible event. The ripening phase does not start until the fruit has developed considerably from the tissues present at anthesis and it is difficult to stimulate ripening before it attains maturity. The ripening changes which are common during softening are accumulation of pigments and changes in cell wall.

Floriculture is increasingly regarded as a viable diversification from traditional field crops due to increased per unit returns and increasing habit of “saying it with flowers” during all the occasions. All over the world, the floriculture sector is experiencing rapid changes. Opening up to the world market in the WTO regime paving way to free movement of floricultural products world wide, globalization and its effect on income generation have all contributed to increase in per capita consumption of flowers in most countries. Noticeable feature of global floriculture is the development and expansion of floriculture in non traditional areas. Netherlands, Italy, Germany, and Japan had strong tradition for growing and consumption of flowers. The concept of commercial floriculture was perpetuated across the world from those regions. Now production centers are developing in Latin America, Africa and also in Asia to meet the demand of consuming countries and also to expand domestic market, commensurate with improved economic conditions, These countries provide highly qualitative floricultural products with low cost price which is finding a favourable place in markets of Western Europe, America and Japan. Emergence of new production centers has made floriculture more competitive and this in turn is benefiting the ultimate consumers.

Plant breeding/genetic improvement aims at altering plant genotypes in a way that they suit human needs for food, feed and industrial raw products and support sustainable plant production. In that sense, plant breeding may be regarded as the evolution of plant type by the will of mankind. Plant breeding/genetic improvement is important because an improved cultivar is the most-economic and least laborious input for farmers.

Plant breeding is one of the early accomplishments of humankind. Many of the cultivated plants are the result of slow and involuntary improvement from wild progenitors by human being over centuries. In fact, the process of domestication of wild plants is one of the most fascinating chapters in the history of humankind. Concept of plant breeding came in the being through domestication as it involved selection of the most desirable types. Among the ancient domesticates, some of the vegetable crops are front-runners, like peas, radish, muskmelon, watermelon, etc. Other present day popular vegetable crops were domesticated later in the Neolithic times. Some species including certain vegetables are still undergoing the domestication process. However, for all practical purposes, the breeders have given up domestication of wild relatives of the cultivated species. Today, breeders often incorporate important characters, like resistance to biotic stresses, adaptability to environments, etc. to the cultivated forms from their wild relatives.

Selection from the available variations is the oldest and the most effective breeding procedure. However, genetic recombination at present forms the basis of modern plant breeding approach. In this respect, Josef Kolreuter’s extensive crossing experiments between 1755 and 1806 were essentially the first attempts to scientifically-reconstruct naturally occurring species and types by combining their characters. Any way, no matter what method is adopted in the breeding approach, it inevitably involves selection, which is the most difficult part of overall breeding process.

The industrial revolution in Western Europe and concomitant flourish of capitalism and increasing commercial agricultural production stimulated breeding activities as a profitable venture of capitalistic economy. Throughout the 19th century, thousands of large and small seed companies were developed in Germany, England and the United States out of this impetus.

Dietary constitution of Indian people is mostly cereal based. However, the cereals supply chiefly carbohydrates. Therefore, there is deficiency of protein, minerals and vitamins, especially vitamin A, riboflavin, vitamin C, etc. in the diet. The dieticians advocate the intake of 125 g leafy vegetables, 75 g other vegetables and 100 g root and tuber vegetables (total 300 g) everyday because vegetables provide all the nutrient components like carbohydrates, protein, fat, minerals, vitamins and water along with roughages, which are the essential constituents of a balanced diet.

India has attained food security by increased cereal production due to green revolution. In case of vegetables, although there has been increase in production from 15 million tonnes during 1950 to 94 million tonnes in 2005 but still more vegetables are needed to meet the minimum requirement of at least 250 g per day per capita. There has also been increasing demand for fresh export and for processing industries. Moreover, there is a pressure for increasing vegetable supply caused by constantly increasing population in a world of limited acres.

Addition of new agricultural land is of course not possible. In this situation, plant breeding can be expected to contribute substantially to greater vegetable productivity. This can be accomplished not only by the breeding of basically higher yielding varieties but also by the development of varieties that help to stabilize production through resistance to various biotic and abiotic stresses.

Vegetables are cheaper source of carbohydrates, proteins, minerals, vitamins and dietary fibers, and hence, assume a place of very great importance in the diet of individuals. All kinds of vegetable are grown almost universally. India occupies the prime position in the production of vegetable crops and is the second largest producer of vegetables in the world. The area and production of vegetables in India have been increasing during the post-green revolution period, and the country is heading towards another revolution in the form of Golden Revolution. However, there is an utmost requirement for genetic improvement of vegetable crops in terms of productivity, qualitative characters and resistance to biotic and abiotic stresses. For any genetic improvement programme, the presence of genetic variation is pre-requisite and mutation is the ultimate source of this heritable variation.

Mutation technique that holds promise of generating a much wider desirable variability than classical breeding has been refined. Out of 2275 mutant varieties worldwide in all crops, as many as 66 mutants are in vegetables. In terms of percentage, China, India, USSR, The Netherlands, The United States of America and Japan account for 26.8, 11.5, 9.3, 7.8, 5.7 and 5.3%, respectively of mutagen varieties in all crops. Such varieties are 3% in case of vegetables. After mutation treatment by a mutagen to a specific plant, DNA alterations (deletion, duplication, inversion, translocation, or transposition of larger DNA fragments, or simple basic pair changes) occur and lead to the DNA sequence change. Hence, new characteristics of that plant are established. In fact, induced mutations supply us with many new plant lines, which may be used as primary materials for crop breeding. Hence, mutation breeding seems to be an effective and ultimate option to improve vegetable crops in the shortest possible time. A large number of new promising varieties in different crops, including vegetables, have successfully been developed worldwide using various mutagens (Chopra, 2005).

Vegetables have always been looked upon as an essential part of diet and are necessary for human health and well-being. Vegetables supply many kinds of nutrients, e.g., carbohydrates, proteins, minerals, vitamins, fibers, phytochemicals, etc. and also add flavour, colour and crispness to foodstuffs. For developing modern day vegetables, breeders have utilized an understanding of genetic principles and applied them for the improvement of these crops. They often make crosses (hybridization) between a crop plant and a related or wild species (a wide cross) enabling valuable genes to be used for genetic improvement of the crops. Over the last few decades, molecular breeding is supplementing plant breeder’s efforts for accelerated genetic enhancement bringing about a revolution in this area. This approach demands efficient procedures for the routine introduction of foreign DNA into plant genomes and utilizing them for the production of novel types of vegetable. In this chapter, attempts have been made to review most of the available molecular breeding techniques, which can routinely be employed in various aspects of vegetable improvement.

Cultivars are developed by selecting for desired traits or by removing undesirable traits that are controlled by genes (the blueprint for all characteristics in living organisms) from existing varieties or breeding lines. The plant species, varieties and clones are identified or selected by their physical features since olden times. However, these traits would change with respect to environmental and climatic conditions. The biochemical parameters like enzymes, proteins, alkaloids, etc. are also likely to change due to the stages of development of plant tissue. Successful selection strategies are dependent on the breeder’s ability to distinguish genetic effects from environmental effects on a visible or measurable trait. Therefore, the scientists resorted to use ‘genetic marker’, i.e., any stable and inheritable variation that can be measured or detected by a suitable method and can be used subsequently to detect the presence of a specific genotype or phenotype, which otherwise is very difficult to detect. Presently, the breeders and scientists all over the world are pursuing mostly DNA or molecular markers.

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.

Diseases of plants are produced by a variety of organisms from plant and animal kingdoms viz., fungi, bacteria, viruses, nematodes and insects. The diseases reduce total biomass (dry matter) production and consequently yield of the crop by general stunting, damage to the leaf tissues, fruits and seeds or by killing the plants. The degree of damage would depend upon the intensity of infection but both need not be proportional. One serious effect of disease is the disappearance from cultivation of otherwise excellent but susceptible varieties.

Vegetable crops have been found to be highly susceptible to biotic stresses from the disease causing microorganisms and insects-pests. The ability of pathogen and insect-pests to attack and proliferate in the host plant is highly specific. There are wide differences in the host plants in response to the attack by pathogens and insects. Although control of the diseases and insects by the use of chemicals is possible to certain extent but indiscriminate use of fungicides or insecticides over the crop has several disadvantages. Besides increasing cost involved in chemical control, residual toxicity of the chemicals such as fungicides, antibiotics and insecticides in food chain and development of resistance against pathogens and insect-pests to different chemicals are serious problems.

Genetic improvement of host plants conferring resistance to diseases and insect-pests is considered to be the best approach in the management of diseases and insect-pests, and this is more particularly true in case of vegetable crops. Indiscriminate use of chemicals in the vegetable sector has led to health hazard. This has resulted in switching towards organic vegetables. However, cost of production of organic vegetables naturally will not permit the common people to consume these products. Therefore, the best option is to induce resistance in the host varieties. The resistant varieties could in turn be an important component in the organic vegetable farming, thereby reducing cost of production to certain extent.

Concern for improvement of nutritional quality of vegetables has arisen in the context of providing nutritional security to our ever-increasing population. Nutritional security denotes the consumption and physiological use of adequate quantities of safe and nutritious food by every member of the family and encompasses the process of equitable distribution among members of household and communities (Nandi and Bhattacharjee, 2002). This would entail the need to ensure a varied food intake, comprising all the essential macro-and micronutrients (protein, carbohydrates, minerals and vitamins), plant pigments (lycopene, beta-carotene, anthocianin, lutein, capsanthin, zeaxanthin, etc.) and other functional phytochemicals (secondary metabolites, like flavonoids, isothiocyanates, glucosinolates, etc.) through a diversified diet. In this regard, production and consumption of vegetables that are the valuable source of micronutrients, beneficial phytonutrients and highly functional phytochemicals hold the key in assuring nutritional security.

Implication of vegetables in diet has been well conceived among the high-income group in the world since human health in recent years has assumed an unprecedently important status. Increased interests in nutrition, fitness and beauty have exaggerated concerns over diet and human health. A new diet-health paradigm is evolving which places more emphasis on the positive aspects of diet. Foods have now assumed the status of functional foods, which should be capable of providing additional physiological benefits, such as preventing or delaying the onset of chronic diseases as well as meeting basic nutritional requirements so with high-income elasticity, the demand for vegetables and perception of diversified diet have been growing steadily, hence, both access and consumption of vegetables have been increasing in the urban and peri-urban population groups. However, meeting the requirements for macro- and micronutrients for most of the population groups in households and communities of South Asia, Latin America and African countries seems far off because of meager presence of vegetables in the diet. In south Asia where meat intake is low, ascorbic acid emerges as one of the most important enhancers of iron absorption. This is attributed to the fact that foods containing vegetables may provide an optimal mix of minerals, vitamins, antioxidants, dietary fibers and other non-nutrients bioactive compounds.

India is contributing about 10% of the world’s vegetables, and in terms of production, the country stands second after China. The existing area under vegetable cultivation in India is around 6.89 million hectare with a production of about 96.54 million tonnes. There will be a demand of 151-193 million tonnes of vegetables in India by 2030 (Dhaliwal et al., 2006). There are extensive crop losses in vegetable crops due to increased insect infestations. Since vegetables are grown round the year, there is carry over of insect-pests across the seasons and also from sowing until harvesting. Vegetables also invite more pest problems because of their cultivation under high fertility conditions leading to high plant succulence. High yielding varieties and hybrids are further more prone to the attack of insect-pests. Insect infestation affects the quality and market value of vegetables adversely and it is estimated that 30-40% of the total production is lost due to the attack of pests (Lal et al., 2004). A large number of pesticides are being used repeatedly to manage the insect-pests in India. Indiscriminate use of pesticides has led to many problems like toxic residues in edible parts of the vegetables, adverse effects on non-target organisms and beneficial insects, resurgence of secondary pests and development of resistance in major pests to pesticides and also environmental pollution. Therefore, latest approach has been to minimize the use of highly toxic insecticides by integrating different strategies of pest control like use of biological control agents, pesticides of plant origin, insect resistant varieties and other cultural practices. In this chapter, efforts have been made to highlight the distribution, host range, identifying characters, biology and nature of damage of important insect-pests of vegetables and also the methods of their management crop or pest wise.

Introduction

Agricultural soils harbour a rich variety of nematode fauna, where they coexist with a myriad of other microorganisms. It has been estimated that one cubic meter soil of highly fertile field may contain as many as 3×10¹⁴ bacterial cells (300 g), 5×10⁸ protozoa (39 g), 1×10⁷ nematodes (12 g) and fungi (400 g), besides other organisms. The nemic fauna comprises of free-living (saprophagous and microbivorous), predatory forms and plant parasites (phytophagous). In addition, certain animal and insect parasitic forms may spend a part of their life cycle in soil. Plant parasitic nematodes (PPNs) exist in poly-specific communities and attack all types of plants- cultivated or wild. They possess a needle-like stylet or spear at their anterior end, which is used to puncture the plant cells and ingest the cell contents. Majority of PPNs dwell in soil and draw their nutrition from plant roots. Only a few forms attack the above ground plant parts such as stem, leaves, inflorescence and seeds. PPNs may be ectoparasites (feed from outside and do not enter plant tissues) or endoparasites (enter inside the plant tissues). The endoparasites spend a part of their life cycle in soil or may come out into the soil to re-infect the other roots. These may be further categorized into migratory or sedentary types. The migratory forms keep on moving, feeding and laying eggs that are scattered in soil or plant tissues. The sedentary nematodes are more harmful and a particular stage of their life cycle infects the plant and establishes a feeding site by modifying plant tissues by their enzymatic secretions. The females of sedentary nematodes usually attain swollen shapes upon maturity and lay hundreds of eggs in clusters.

Plant parasitic nematodes are ubiquitous, and so far, more than 1800 species have been recorded. They are obligate parasites and must feed upon plant hosts, thus, debilitating the plants to some extent. The extent of direct damage by the nematodes to plants depends on several factors viz., nematode density in soil, nature of parasitism (ectoparasite or endoparasite), host susceptibility, cropping pattern, edaphic factors (mainly soil texture and moisture) and ambient climatic conditions (like temperature and relative humidity). Nematodes, by themselves, rarely kill the plants to ensure their own survival. Nematodes also inflict considerable indirect damage to crops by interacting with other plant pathogens (fungi, bacteria and viruses) to cause disease complexes in which nematodes act as incitants, aggravators, or vectors.

Vegetables being good source of carbohydrates, proteins, minerals, vitamins and dietary fibers constitute important component of human diet. These are the cheapest source of natural protective food and increase the palatability. India is the second largest producer of vegetables next to China. Diseases are inherent component of agro-ecosystem, which must be dealt with continuous and knowledgeable basis. Diseases in the standing crop from the seedling stage until harvest and spoilage caused by microorganisms during transit, storage and marketing are major constraints in increasing production and availability of vegetables. At different stages of vegetable production, disease management requires several approaches, and it is more successful, if it is integrated into crop production system. Since vegetables are mostly grown year after year in the same fields especially near towns and cities, therefore, concerted efforts are required to manage the diseases. More than 300 diseases have been reported to occur on vegetable crops and it is beyond the scope of this chapter to discuss all the diseases. However, brief description of etiology, diagnostic symptoms and management practices being adopted are presented here for the economically important fungal and bacterial diseases of vegetable crops.

Plant viruses, like all other viruses, are obligate intracellular parasites that do not have the molecular machinery to replicate without the host. The plant viruses are defined as viruses pathogenic to higher plants. The discovery of plant viruses causing disease is accredited to Beijerinck who determined in 1898 that the plant sap obtained from tobacco leaves with the mosaic disease remained infectious even after passing through a filter. This was in contrast to bacteria, which were retained by the filter. Beijerinck referred to the infectious filtrate as a contagium vivum fluidum, thus, he used modern term virus.

Viruses occasionally cause significant problems in vegetable crops. However, the prevalence and severity of viral diseases differ from year to year. Aphids spread many of the viral diseases observed in vegetables. There are two types of viral transmission by aphids, i.e., persistent and non-persistent transmission. It is important to understand the difference between these two because persistent and non-persistent viruses differ both in their uptake and behaviour within the insect vector, consiquently, tactics used to limit their and spread vary considerably. In persistent transmission, the aphid usually carries the virus for life. Uptake of virus requires extended feeding and after an incubation period of several hours or days, the virus replicates and circulates within the insect. Because of the time required for feeding before acquisition by an insect vector, the spread of persistent virus is favoured by colonizing aphid species that spend time in the crop. Controlling the aphid vectors with insecticides can reduce the spread of persistent plant virus significantly. In contrast, aphids can acquire non-persistent viruses (NPV) within a few seconds after sampling an infected plant. Winged migratory aphids can move quickly from infected plants onto healthy ones, transmitting the virus in the process. Aphids rapidly lose the virus particles from their mouthparts, which are cleaned when they feed on the next available plant and are unable to transmit disease to additional plants. Because of the speed in which aphids acquire and transmit non-persistent viruses, insecticides are not usually effective in controlling their spread. One of the most common viruses found in many vegetable crops is cucumber mosaic virus (CMV). This is transmitted by several aphid species in a non-persistent manner. There are several strains of CMV that can infect over 775 different plant species in 85 families including snap bean, peppers, tomato, lettuce, tobacco and sugar beets. Symptoms vary depending upon the plant species infected but range may be from yellow-green mottling on leaves and fruits to severe stunting of plants. The viral diseases affecting different vegetable crops are being discussed below:

Post-harvest deterioration primarily means the loss of commodity after harvest. It is one of the serious problems for producers, distributors and consumers. Post-harvest deterioration of perishables is the spoilage of fruits and vegetables after harvesting. Perishables are the feed commodities with moisture content between 50 and 90%. Fruits with the size of 5 g to 5 kg or more, high to very high rate of respiration, high generation of heat, soft texture, easily damageable nature and shorter shelf life are more prone to the microbial damage. The post-harvest losses are caused either by pathological, physiological and mechanical means or combination of all these. These perishables because of having minerals, vitamins, and photochemicals (essentially required for the human health) become victim to the several biotic and abiotic factors easily. Once these fruits are detached from the plant are deprived of essential ingredients as hormones, nutrients, water and other requisites. These biotic and abiotic factors apart from rendering the produce unfit for human consumption reduce the aesthetic value, substantial decrease in food value and also organoleptic quality of the vegetables. The fleshy produce are prone to the exogenous agencies such as fungi, bacteria, etc. as well as other endogenous factors such as respiration, senescence, etc. which may lead to poor quality of the produce and also affect market quality. These perishables continue to respire and may carry out various biochemical activities, leading to ripening subsequently to senescence and making them more susceptible to microbial damage. In addition, tropical conditions prevailing in India, which are characterized by high temperature conditions, are optimal for fungal and bacterial infections. In India, the post-harvest losses of fresh fruits and vegetables are estimated to be about 30%. The post-harvest losses have been recorded are 5-20% at farmer’s field due to pre-harvest infection and sorting, 15-20% due to faulty packaging, 30-40% during transportation and 30-40% during marketing.

In spite of late introduction, different forms of chilli (Capsicum spp.) did spread throughout the length and breadth of India. Diverse soil and climatic conditions prevailing in different parts of Kerala have contributed to the development of different ecotypes in chilli. Warm humid climate in the coastal belts, dry and arid climate in the central eastern parts and mild subtropical to temperate climate in the high ranges provide ideal condition for development, maintenance and spread of different ecotypes in the crop. Plethora of chilli varieties capturing the markets of Kerala comprise of different species.

Capsicum chinense commonly known as Ney Mulaku, Karanampotti Mulaku is gaining popularity in the state due to increasing demand from Maldives during Ramzan period. Hence the crop is also known in yet another name Mali Mulaku. This species is characterized by perennial and spreading nature with medium sized oblong to round, fleshy and highly pungent fruits. It  yields substantially higher under shaded condition and there is less incidence of diseases like bacterial wilt and collar rot. Hence the species is ideal for homestead cultivation. Due to its tolerance to shade, the species can be successfully grown as an inter crop in coconut, rubber, pepper and banana plantations.

Greens and salad crops are grown for their foliage and are used since antiquity in soups, boiled, pickled or eaten raw and are recognized as important ingredients in the diet. Stephen Switzer, in Practical Kitchen Gardner (1727) identified 30-40 species as raw salads. Plants like Purslane, Burdock, Orache, Borage, Salad Burnet, Sea Kale, Dandelion, French Sorrel, Alexanders and many other plants are used as greens.
 
Greens and salads are very well represented in the garden works of John Randolph and Joseph Prentis in Williamsburg who  described that markets carried a wide selection of greens making available to the general public. But the salad greens were not mentioned in local diaries as often as common vegetables like cauliflowers, artichokes or melons, because they were used more as a garnish than as a main dish.
 
The popularity of individual varieties of greens changed over time. Many of the minor greens, like Purslane and Alexanders were common in the 17th century and before, but largely disappeared by the 18th century. Rocket, or Arugula, was listed by all authors in 16th and 17th century works but fell out of favor in England by the middle of  18th century.

India is the second largest producer of vegetables in the world. Indian Council of Medical Research, New Delhi recommends intake of 125g leaf vegetables, 100g roots and 75g other vegetables/ day / adult for a balanced diet. Green leaf vegetables occupy an important place among the food crops as these provide adequate amounts of many vitamins and minerals for humans. Besides this, leaf vegetables are easy to grow and readily fit in any cropping system owing to its short duration. They are rich sources of carotene, ascorbic acid, riboflavin, folic acid and minerals like calcium, iron and phosphorus (Ramdasmurthy and Mohanram, 1984).
 
In nature, there are many greens of promising nutritive value, which can nourish the ever increasing human population. In spite of their nutritional importance, in India, leaf vegetable production is limited to kitchen gardens and market gardens due to various reasons. Although they can be raised comparatively at lower management costs even on poor marginal lands, they have remained underutilized due to lack of awareness and popularization of technologies for utilization.