Chapter 1
Vegetable Breeding : A Perspective 1. Introduction 2. Importance of vegetable 2.1. Food security 2.1.1. High productivity per unit area 2.1.2. Economic security 2.1.3. Employment opportunities 2.2. Nutritional security 2.2.1. Nutritive value 2.2.2. Therapeutic Value 2.2.3. Role in fighting malnutrition 2.2.4. Anti-nutritional factors 2.3. Role in sustainable agriculture 3. Vegetable breeding 3.1. Nature of vegetable breeding 3.2. Disciplines related to vegetable breeding 3.3. Objectives in vegetable breeding 3.4. Scope of vegetable breeding 4. Basis of vegetable breeding 5. References
1. Introduction
Vegetarianism has been characteristic of Indian food system. Contribution of vegetables to Indian diet remained low until recently and yet it stands at 175g per caput per day. It is lower than one recommended by FAO ( 300g per caput per day) for a balanced diet. India is the second largest producer of vegetables in the world, first being China. Production figures have been 59,120 and 456 million tons in 1992 for India, China and world respectively (FAO yearbook) which rose to 91.8, 367.9 and 798.2 million tones in 2003 (Rai, 2005). It indicates substantial increase in production but human population rise continues to broaden the supply demand gap. This looks for further enhancement in vegetable productivity. Breeding high yielding open pollinated varieties and hybrids and exploitation of location specific component of genotypic performance are the only options left to reduce this increasing gap in view of decreasing land resources.But the breeding efforts have been inadequate particularly in the Indian sub-continent where emphasis mostly remained towards production aspect (Ram 1998) Vegetables are herbaceous plants, which are consumed either raw or cooked. The use of vegetable plant or parts thereof varies with kind of vegetable ranging from root, stem, leaf, inflorescence, fruit, flower to grain ( immature or sprouted). Hence a precise definition for vegetables is difficult but may be defined as “edible herbaceous plants or their parts used for culinary
purpose either fresh or dried.” The dietary importance of vegetables is now recognized all over the world as evident from FAO/ WHO comments that fruits and vegetables are potential source to tackle spreading menace of malnutrition globally. At present more than 70 vegetables find cultivation on 42.6 million ha area in the world. Major vegetable producing countries are China, India, U.S., Turkey, Italy, CIS, Spain, Egypt, Mexico and Nigeria. 2. Importance of vegetables
Diversion of financial and manpower resources is related to socio-economic importance of a thing. Aryans appreciated very well the tempting succulence, pleasing flavor, high nutritive and protective values of vegetables. Recently, the world is tempted by invigorating values of vegetables. This indicates that vegetables have appreciable role in sustainable development through food and nutritional security (Sharma 2005, Bagchi and Hazra 2005). Therapeutic values of vegetables are also now well recognized. Economic significance of vegetable in light of latest researches is summed up below:2.1. Food security
Food security has two major dimensions namely availability of food, which is related production and second one is access to food, which is related to economic status or purchasing power of the people. With the rapid increase of population, per caput agricultural production is declining and food security is gaining socioeconomic importance. Countries like India where 58.9% workers depend upon agriculture for their livelihood, farming plays key role in sustaining socioeconomic status of human society. New technologies to raise food production and generation of employment opportunities are fundamental to human food security in India. Vegetables by way of high productivity, more diversity, variety of processed products and numerous ways of consumptions qualify to be the competent candidate for ensuring food security for millions. Some of the facts are briefly enumerated below:2.1.1. High productivity per unit area
With shrinking arable land resources and increasing human population, vegetable crops can ensure food security because of their high productivity per unit area (table1), Grain yield of cereals remain around 50 ±10 q/ha while in most of the vegetables it is around 150± 150 ±20 q/ha, leafy vegetables may yield as high as 600 to 700 q/ha, Much high yields are realized under protected cultivation conditions. For example in Denmark under glasshouse conditions, tomato yield of 202 ton is obtained (Kale et. al. 1986). Sharma (2002) has also reported tomato yield up to 85ton/ha from Ladakh region under protected conditions of polyhouse.
Shifting over to vegetable from cereals means at least doubling of production. Considering the potential yield of cereals and vegetables, productivity of 4 times more in tomato over rice, 11 times more in green peas over Chickpea and 8 times more in bottlegourd over maize is possible (Table 1). Further boost in productivity of per unit area is possible because of short duration nature of vegetables and availability of mechanisms for exploitation of hybrid vigor. Most of the vegetables are ready for marketing in 80± 80±10 days and 85 F 1 hybrids have been released in different major vegetables for general cultivation in India by 2005. 2.1.2 Economic security
Capability of a crop to ensure economic security stems from providing enough food, good food, diverse food (dishes) and adequate availability round the year. 4000 species contribute to the world of vegetable crops and about 70 find cultivation on wider scale in different regions of the world encompassing temperate, tropical, sub-tropical and their intermediates. It reveals the importance of vegetable in diversification of agriculture. Due to diverse agro-climates, fresh vegetables are available round the year in India. More productivity as compared to field crops that too, in lesser time imparts stability to the economic status of farmers. Vegetables provide means of livelihood to many persons involved in transportation, retail sale, storage and post harvest processing etc. there by strengthening economic status of the society. 2.1.3 Employment opportunities
Vegetable farming is labor intensive and offers employment opportunities during production, handling, storage, post harvest processing and export etc. Vegetables have potential to feed billions. When unemployment has assumed global significance, various facets of this field need to be critically investigated Vegetables provide 20-30 times more foreign exchange per unit area and demand on average 860 person-days per ha per annum as against 143 persondays for cereals. Quality seed production is technical but offers good scope for business opportunity. Hybrid seed production has attracted private sectors. Thousands are earning their livelihood by producing and selling seedlings of several vegetables. Post harvest processing remains highly under-utilized in our country as only 1.80% of the total fruit and vegetables is processed. Post harvest losses are around 25% amounting to revenue loss of Rs 8000 crores per annum. Losses can be reduced by proper packing, storage, drying, and preservation and canning. All these aspects open avenue for employment. India is export market of both fresh and processed vegetables. During 2003-04, there was export of fresh and processed vegetable to tune of 1.9 and 211.2 lakh ton valued Rs.252.3 and Rs.520.5 crores respectively. Competition in international trade is growing and complicated by regulations of WTO. In addition, steady supply through stable and quality production are the only
prerequisite conditions that can lend survival at the global level and leading to enhanced business opportunities in vegetables export. Organic vegetable production in the light of growing global demand for organic food at the rate of 30% and consultancy are the other areas where technical expertise can be used for self-employment. 2.2. Nutritional security
Food hunger touches a mark of 850 million while the figure for malnutrition (over-nutrition and undernutrition) stands at 2.0 billion. Vegetables are staple food of many people living in the different regions of the world and FAO considers them a potential source to fight spread of micronutrient malnutrition (hidden hunger). Protective role of vegetables is now well documented against several diseases and nutritional deficiency disorders. 2.2.1. Nutritive role
Nutrient composition of many vegetables has been estimated and their nutritional classification has been done (table 2). They enrich dishes with minerals, vitamins (primarily vitamin A, and vitamin C) and dietary fibres. Dietary fibers of vegetable once considered unimportant components, has been now found of high therapeutic value. They prevent constipation by regulating bowl movement. Their role in prevention of appendicitis, colon cancer, diabetes, diverticulosis, gallstones and obesity is also advocated (Dreher 1987). Fibers are wide range of polysaccharides like cellulose, hemicelluloses, lignin, gums, pectins and mucin. It is better to take at least 50g of green vegetable such as spinach, amaranth, fenugreek, drumstick, kale, cabbage or methi etc because they are rich in betacarotene vitamin C, riboflavin, folic acid, calcium and iron (See chapter on quality improvement). However, Chauhan (1979) advocated that for a well balanced diet about 300 gm of vegetables were needed per capita per day comprising 90 g of root vegetables, 120gm green leafy vegetables and 90 gm other vegetables. 2.2.2 Therapeutic value
Epidemiological studies have revealed that diets rich in vegetables are associated with reduced incidence of lung cancer, beneficial effects on kidney function, reduced coronary disorders, and diabetes, slow down age-related declines in brain function. Intake of phytochemicals such as carotenoids, tocopherol, ascorbic acid, flavoniods etc (table3) have been implicated in protection against human cancers and cardiovascular diseases. Bagchi and Hazra (2005) have enlisted possible protective mechanisms of phytochemicals against the chronic diseases through such as:a) Quenching of singlet oxygen b) Scavenging of peroxyl radicals c) Modulations of carcinogen metabolism
d) e) f) g)
Inhibition of cell proliferation Enhanced cell differentiation differentiati on via retinoid Stimulation of cell to cell communication Enhancement of the immune response
Thus, the phytochemicals are strong anti-oxidants and act as scavengers of free radicals which are involved in cell damage and tumor proliferation. Whereas protective role of vitamin C, pro-vitamin A and dietary fiber are well established. Epidemiological evidences also support the protective importance of vegetable consumption in human health. 2.2.3. Role in fighting malnutrition st
According to reports of the Commission on the Nutrient Challenges of the 21 century, around 30 million infants are born each year in developing countries with intra-uterine growth retardation. Worldwide there are more than 150 million underweight pre-school children and more than 200 million with stunted growth. If this pace continues then by 2020 about one billion children will be with impaired mental development. Food based approaches like work for foods are the possible solution to meet the challenge of nutritional security. Besides productivity, it has dimensions of quality, diversity and food accessibility.
Human food requires iron calcium, zinc, copper, arsenic, boron, chromium, fluorine, iodine, manganese, molybdenum, nickel, selenium, silicon and vanadium. Plant foods are adequately enriched with them, particularly the green leafy vegetables. They are the cheap and widely available sources. Awareness and popularization among rural masses is needed for their regular consumption. 2.2.4 Anti-nutritional factors
Wide varieties of anti-nutritional biomolecules are found in vegetables. They interfere with digestion and show toxicity at high concentrations. Examples are lectins, isoflavonones, S-methyl cysteine sulfoxide, glycoalkaloids, glycosinolates, nitrates, oxalates and furano-coumarins etc. Potato tubers produce toxic compounds solanin and chacoline when stored improperly. Leafy vegetables often show high concentration of oxalic acid, cucurbits contain glycosides, tomato contains tomatine, and asparagus show saponins which are toxic to human being. High nitrate level in vegetables may lead to formation of N-nitroso compounds with secondary or tertiary amines which are reported to be potent carcinogens. Nitrate and oxalate content are related to genotype of a variety, nitrogen status of soil and rate of fertilizer application, indicating that both breeding and management efforts are needed to reduce anti-nutritional factors in vegetables. 2.3. Role in sustainable agriculture
Sustainable agriculture is a system, which advocates judicious use of natural resources such as land, water and biological species. Vegetable crops can play role in sustaining productivity in following ways:a) Crop diversification: World wide more than seventy vegetables find cultivation on large scale. They are of comparatively short maturity duration and fit into several crop rotations. Thus, vegetables are an effective and economical source of diversification at the farm. Crop rotations not only increase productivity per unit area but also protect soil from health deterioration, prevent proliferation soil borne diseases and pests. Besides they add to the diversity of dishes which are diverse in taste, nutrition and palatability.
b) Provide adequate amount of plant residues that can be used as fodder for animals or can be used as raw material for making compost. c) Make the farming systems economical viable for small and marginal farmers because of higher productivity per unit area. d) Vegetables are adapted to wide variety of climates and can be grown as mixed, companion and intercropping crop. e) Vegetables have aesthetic value. 3. Vegetable breeding
Vegetable crops have been excelling other agricultural crops in per unit productivity. However, breeding efforts received well attention only in field crops both at national and international levels. Vegetables were taught in horticulture. It is very recently that the economical role of vegetable science is being taught as independent discipline in agricultural universities vegetable breeding is now receiving focal attention breeding in vegetables science. There is need to give this aspect an exhaustive treatment in relation to vegetables crops. Nonetheless vegetable breeding is an integral part of plant breeding but in this will be remodeled to suit to breeding for different vegetables crops. “ Vegetable breeding may be defined as” art and science for genetic improvement of vegetable crops.” Earlier efforts of breeding began with domestication of wild plants that resulted into several cultivated types. Introductions followed domestication whereby plants were distributed in different agro-climates and evolved further. In fact, all these efforts come under breeding so vegetable breeding is consisted of all principles and methods that favorably change the genetic constitution of plants. Now-a- days the focal point of vegetable breeding is evolving of new varieties which are better in economic traits. Thus in more practical ways “Vegetable breeding is the science involved in evolving of varieties superior to the existing ones”. The
success of whole gamut lies in systematic and effective reshuffling of genome so that genetic potential of a vegetable crop is realized. Vegetable breeding is still developing science where plant biotechnology, molecular biology and transgenic are the new aspects added to it . Conclusively, vegetable breeding activities range from crop domestication, introduction, conservation of genetic resources to genomic modifications that lead to genetic up-gradation of vegetable crops. These activities ultimately aim at enhanced economic utilization. 3.1. Nature of Vegetable breeding
Vegetable breeding comprises wide range of activities that involves selection of useful variation whether present naturally or created artificially in vegetable crops. The process of selection is central to vegetable breeding and requires both artistic skill as well as scientific knowledge for effectiveness. From experiences of early breeding to modern approaches breeder’s skill and keenness seem important besides applications of scientific analytical techniques. The art is highly subjective where as science is highly objective. Science involves systematic gathering of information that consorts of observation, formulation of hypothesis, experimentation, analysis and conclusion indicating either rejection or acceptance of hypothesis. Earlier efforts of selection were based on visual observation where skill mattered much Man knew nothing about genes, their inheritance and interaction with environments. Gene transfer technologies were not known the approach was purely an art. However now techniques of genomic reshuffling, evaluation of inheritance of characters are very well known and vegetable breeding is now largely based on scientific knowledge that involves multidisciplinary approach. After the discovery of Mendel’s laws of heredity statistical treatment to the scientific observations became pivotal for directional and additive improvement in crop plants. Despite the various advanced techniques available, art continues to play the key role in identification of desirable plants in segregating generations of crosses. Mass selection the basic and most extensively used method for plants improvement demands breeder’s skill and observational keenness. Attempting of hybridization is much depended on breeder’s skill. Selection of plants in large population for recording observations is based on experience and visual efficiency of the vegetable breeder and then scientific treatment follows. Thus, modern vegetable breeding is largely scientific but is very well supported by the art of experiences, skill and keenness of breeder handling the plant population. A modern vegetable breeder ought to know more about his crops which demands knowledge about related disciplines. This will enable vegetable breeder to develop varieties that excel the existing varieties in yield and quality attributes.
3.2. Disciplines related to vegetable breeding
A vegetable breeder should have knowledge across the discipline to successfully achieve the targets related to genetic improvement of vegetables. Tailoring of vegetable crops seeks acquaintance with subjects such as :Botany: Vegetable improvement is ultimately assessed in terms of morphological change. Morphogenesis and reproduction are fundamental to phenotypic description. Taxonomy is needed to explore the possibility of gene transfer across the species or genera. Genetics: It is now well known that each character is determined by a gene. Its expression is influenced by various interactions among genes. Genetic modifications are basic to evaluation of diverse varieties. Knowledge about chromosomes gene structure and functions helps in genetic manipulation in a species. Plant biotechnology: Plant biotechnology mainly deals with foreign gene introduction through recombinant technology and referred as transgenic technology. Somaclonal variation, in vitro mutagenesis, gametoclonol variation, anther culture are some other aspects which have direct relevance to vegetable crop improvement. Hence, a modern vegetable breeder should be well versed with these techniques for generation of noble variation in vegetables with respect to economic traits. Plant pathology: Vegetables are host to several pathogens and breeding for disease resistance is an essential parameter for development of superior varieties. So knowledge of pathogens, their mass multiplication and inoculation techniques is essential for a vegetable breeder. Entomology: Several pests haunts after vegetable crops because of their soft and succulent nature. Vegetable are mostly eaten fresh or raw. Here pesticide contamination is serious concern in relation to human health. Breeding for pest resistance has assumed greater significance may it through conventional or innovative means. Pest rearing, multiplication multiplicati on and inoculation are central breeding methods for insect-pest resistance. Plant biochemistry: Besides yield, several vitamins, minerals and therapeutic compounds are improvement target in vegetables. Quality breeding has assumed a greater role in vegetables with the FAO notion that these are more amicable and natural means of tackling the menace of hidden hunger (malnutrition). Hence for chemical analysis of proteins, vitamins amino acids and other quality imparting organic compounds knowledge about plant biochemistry would be required. Statistics: Evaluation of high precision needs statistical application. Statistical designs like randomized block design, latin square and factorial etc are used to
find the best treatment. Various statistical tests, experimental designs and field plot techniques are required for interpretation of crop performance. Plant physiology: Plant performance is net outcome of how efficiently the physiological processes are sequenced, adaptation has physiological basis. Physiological alterations are also acknowledged in response to various abiotic and biotic stresses. Photosynthesis is key process of biomass production and subsequent metabolic manipulations and lead to more efficient plant type, the ultimate goal of vegetable improvement. Hence, a vegetable breeder must acquire adequate knowledge about physiological processes.
Marketing, post harvest technology and value addition are the other fields concerned to a vegetable breeder. A single person may not be able to acquire knowledge about so many disciplines, as a result modern vegetable breeding is a team effort where scientists from pathology, entomology, biochemistry plant physiology, plant biotechnology need to work in association. 3.3 Objectives of vegetable breeding
Vegetables breeding aims to improve the plant characters that have economic importance. The changes in plant morphometry have genetic basis and are thus permanent. Alterations desired in crops vary from place to place depending upon local preferences. Objectives in a crop vary with time, needs and cultivation practices. Some general objectives in vegetable breeding are described below:3.3.1. Higher productivity
More yields per unit area remain even today the major objective in vegetables, particularly in the developing world. Hybridization is commonly adopted approach to develop better superior open pollinated varieties or F 1 hybrid. Till date 87 F1 hybrid varieties have been released in India for general cultivation in addition to more than 350 open pollinated varieties. 3.3.2. Better quality
Growing health consciousness among masses is shifting people’s preference for better food products. Quality in general perception includes all those parameters that affect its marketing, shelf life, edibility and nutrition as well. Fruit shape, size, color, firmness, flavor, pigments, vitamins, proteins, essential amino acids and minerals are quality attributes in various vegetables. Important quality characters of some vegetables have been discussed separately in chapter on quality breeding. 3.3.3. Maturity duration
Short duration varieties now dominate the production scenario. Early maturing varieties production scenario. Early maturing varieties are available in cauliflower, radish, knol khol, tomato, peas, potato and onion etc. Varieties suitable for different seasons or different date of planting are also available. Round the year cultivation of knol khol and radish has been possible in some parts of Jammu of J&K. 3.3.4. Breeding for resistance against pests and diseases
Pest attack many a time plant part that is directly consumed by human being. Sprays of chemical for pest control often lead to pesticide contamination causing health hazards so resistant breeding in vegetables is especially endowed with socio-economic consequences and holds more promise. In some vegetables like tomato, potato, brinjal and soybean pest resistant transgenic varieties have been developed. Pest resistance varieties give safe and stabilized production. 3.3.5. Photo-insensitivity
Development of photo-thermal insensitive varieties has considerably the area of cultivation in several vegetables. Breeding of high temperature tolerance strains in temperate vegetables has enabled their cultivation in intermediate as well as subtropical areas. Conversely cold tolerance in tropical vegetables is helping in development of strains for temperate areas. 3.3.6 Determinate growth
Along with short maturity duration, emphasis has been on determinate growth. Determinant types are physiologically more efficient. Example are determinant strains in tomatoes, peas etc. 3.3.7. Drought resistance
Vegetables are the crops that need small quantity of water in the form of light irrigations periodically for continuous moisture regime and this is the reason that vegetables are considered crops of assured irrigation area. Varieties with resistance to moisture stress have been developed but few. 70% cultivated area of our country is rain fed and is adjudged unfit for vegetable cultivation. However vegetables like green peas, some leafy vegetables and melons in cucurbits offer scope for cultivation under rainfed farming. Breeding for drought resistance varieties is needed in vegetables to make them important component of rainfed agriculture. 3.3.8. Reduction in anti-nutritional factors
Trypsin inhibitor, oxalic acid, phenolic contents, nitrate context, bitter principle of cucurbits are some of the undesirable molecules in vegetables. Breeding efforts are used to reduce or eliminate them. Lowering of anti-nutritional factors adds to nutritional value, enhances marketing avenues of vegetables. 3.3.9. Cold tolerance
It is especially desired in summer vegetables at seedling or early vegetative growth stage. For instance, Cold tolerance in chilli, tomato and brinjal help in their nursery raising during mid-winter or else the seedlings have to be provided protection. Tolerance against frost is required even in winter vegetables. 3.3.10. Plant type
Modification in plant type is basic to vegetable breeding. Agronomic features are changed depending on climate. It includes change in growth habit, plant canopy, plant height, lodging resistance and fertilizer response etc. Desirable characters for a vegetable in an ecosystem may be identified and efforts are made to bring these characters in a genotype. This approach is known as ideotype breeding. Objectives are usually need based and a vegetable breeder has to arrange them in relation to economic significance. Hence objectives keep on depending on the changing situation. 3.4. Scope of vegetable breeding
Per unit land resources are decreasing globally. In India, the figure stands at 0.12 ha. It demands promotion of cultivation of those crops which give maximum productivity per unit area. Vegetables excel cereals at least twice and also in gross yield of caloric value, they are comparable to them. For instance, wheat yields on an average8, 700, 000 K cal per ha whereas tomato yields 12,540,000 K cal and that cabbage yields 6,000,000 K cal per hectare. Further role of vegetables in food and nutritional security described earlier reflects considerable scope of vegetable breeding. Periodical studies carried by ICMR, New Delhi and National Institute of Nutrition, Hyderabad show that deficiencies of iron, vitamin A and Vitamin C are common and are responsible for several diseases. They attributed it to low intake of fruit and vegetables. Vegetables are the cheapest source of protective foods like dietary fibers, minerals and vitamins. Role of vegetables in balanced diet is well established and their consumption is described essential as per recommended dietary allowances (RDA) given by ICMR for Indian people (table 3). Medicinal applications of
vegetables appear to be future area which will further enhance scope for breeding vegetables for therapeutic uses. Most of the agricultural systems in the developing world are incapable to supply enough micronutrients (14 trace elements and 13 vitamins) to meet human needs. Besides farm management, Graham et al (2001) describes that breeding approaches like varietal selection, molecular-genetic crop transformation, inheritance of nutritional traits, genotype environment interactions, needed to be studied for their yield and quality improvement. Vegetable breeding for nutritional balance is the need of the hour if we want to achieve target set by World Food Summit 1996 in Rome Declaration on world food security (We pledge our political will and our common and national commitment to effort to eradicate the hunger in all countries with an immediate view to reduce the number of undernourished people to half their present level not later than 2015). Genetic manipulations in vegetables will receive priority considerations in the following areas:
Breeding for antioxidants (β ( β-carotene, vitamin C, selenium, magnesium, and zinc etc.) Developing transgenic varieties possessing pest resistance (Purposely to reduce number of pesticide sprays) Genetic built- in capacity to tolerate moisture stress (so that acreage under vegetables increases via promotion of rainfed cultivation). Breeding for shelf-life and value addition quality traits. Pyramiding genes of economic importance.
4. Basis of vegetable breeding
Like begets like is justified by constancy of factors stated by Mendel. However the off springs are not exact replica of parents. They usually differ in magnitude of several biometrical traits from their parents. This fact was very well recognized by Charles Darwin and described as organic evolution in his treatise ‘origin of species’. The studies basically disclosed two universal facts about the biological world namely, heredity and variation. Heredity preserves the individuality of species while variation endows a genetic plasticity to species to adapt to changing environment and progressively evolved towards better types. Variation in a character is a prerequisite to its improvement. Absence of variation means no improvement is possible. Once the variation is present in a species it is utilized both by man and nature for the species advantage. Man has superceded nature so far utilization of variation for improvement of cultivated plants is concerned. Figure 1 depicts the various means of evolution in cultivated plants. The whole program comprises the following steps:-
a) Variation
Causes of variation are known. Mutation and recombination following hybridization generate a lot of variation. Introduction and domestication are carried with objectives of encouraging use of desirable variations. Variation can be of two types, genetic and environmental. Environmental variation is nonheritable and eludes the selection process. It is not of much use. Genetic variation is heritable and is used in vegetable improvement program. Every effort has to be made to keep the plant population rich in genetic variation. In case of its low magnitude, some artificial means are used to create more genetic variability (Fig 1). c) Selection
Selection is the process of isolating superior genotypes or culling of the inferior types. Effectiveness of selection corresponds to the amount of variation due to genetic factors. As the selection is based on phenotype which represents both genotypic and environmental variation so various selection methods have been developed to reduce the environmental component of variation in the selected plants. b) Evaluation
Evaluation is done to know the performance of selected plants or entries in comparison to standard varieties. The process may be repeated over years, over many locations to find out the stability of the selected strains. Three year evaluation at various locations is the routine procedure followed in all India coordinated Research projects on vegetable crops. c) Minikit trials
A selected entry performing good for three years is put to minikit trials. Minikits of the selected entry alongwith standard check are conducted in farmer’s fields for one or two years. This step is not essential for identification of an entry at national level but very much required when the entry is to be released at state level. e) Seed multiplication
As a norm breeder seed of the identified variety or entry is produced by the sponsoring institute under the supervision of concerned breeder. Foundation and certified seeds are produced by concerned developmental agencies or by the progressive farmers under the supervision of state seed certifying agency. Continuity is must in the above steps for successful vegetable breeding programme. Personally involved and dedicated efforts can
only land at destination. Negligence at only one step means breakage in the chain of variety development process and amounts to wastage of resources. The progress of such programs must be periodically reviewed and problems should be immediately addressed to ensure steady progress. 5. References
Bagchi, D.K. and Hazra, P.2005. Role of vegetable in food and nutritional security and poverty alleviation. In, souvenir, 23rd Annual group Meeting, AICRPon vegetable crops. BCKVV, Mohanpur,(W.B.)Pp.1-6. Chauhan, D.V.S. 1979. Vegetable production in India. Ram Prasad and sons, Agra (U.P.).Pp.352. (U.P.).Pp.352. Dreher, M.L.1987. Handbook Handbook of dietary fiber . Marcel Dekker, New York. P.205. Graham, R.D.,Welch, R.M. and Bouis, H.E.2001.Adddressing micronutrient malnutrition through enhancing the nutritional quality of staple foods. Principles, perspectives and knowledge gaps. Adv. Agron. 70:77-141. Kale, P.B., Dod, V.N. and Gonge,V.S.1986. Importance of vegetable and its prospects for improvement in India. In, Vegetable crops in India (Bose ,T.K. and Som, M.G. eds.) NayaProkash Calcutta-6. Pp.1-20. Rai, Mathura. 2005. Recent advances in vegetable research and development in rd India. In, Souvenir , 23 Annual group Meeting, AICRP on vegetable crops, BCKVV, Mohanpur (W.B.) Pp.7-26. Ram, H.H. 1998. Vegetable breeding, principles and practices. Kalyani Publishers, Ludhiana. Sharma, Jag Paul. 2005. Role of vegetables in human food and nutritional security. Paper presented at Ist J&K state science congress held at university of Jammu from Feb.7-9,2005. Sharma, Jag Paul. 2002. Crop production technology for cold arid region. Kalyani Publishers, Ludhiana. Pp.226. Singh, B.D.1983. Plant breeding, principles and methods. Kalyani Publishers, Ludhiana Pp.620.
Natural means
Artificial means
Domestication Germplasm collection Introduction Mutation
Hybridization Mutation Polyploidy Somaclonal variation Transgenics
Genetic variation in plant population
Selection
Evaluation
Minikit Trials
Identification
Seed multiplication and distribution
Figure 1. Elements of vegetable Breeding. Modified from Singh (1983)
Table 1. Comparative productivity of field crops vs. vegetables
Crop
Rice Maize Wheat Chickpea Urdbean Mustard Tomato Potato Onion Cauliflower Methi Bottle gourd Peas Okra Brinjal
Realized/ Potential Yield (q/ha) 50 40 40 20 10 12 300 250 110 150 304 370 150 180 200
Comparative percentage increase Tomato over rice Potato over wheat Bottle gourd over maize Peas over chickpea Onion over mustard Okra over maize Okra over rice
Increase/Decrease over base 100 -50 -60 -60 -80 -90 -88 +200 +150 +10 +50 +104 +270 +50 +80 +100
600 620 825 750 816 450 360
Table 2. Nutritional classification classification of vegetables
Carbohydrates Protein Fat Pro-vitamin A ( β-carotene) Vitamin C (Ascorbic acid) Folic acid (Vitamin B9) Thiamine ( Vitamin B1) Niacin ( Vitamin B3) Riboflavin ( Vitamin B2) Iron Calcium Phosphorus
Potato, sweet potato, dry beans, yam, plantain, cassava Beans, sweet corn, peas, leafy legumes Mature seed of legumes and cucurbits Carrot, Squash, tomato, pepper, green peas, green leafy vegetables, sweet potato Crucifers, tomato, pepper, melons, immature bean seed, leafy vegetables, bean sprouts Spinach, leafy vegetables and beans Peas, cauliflower, muskmelon, yam, spinach, potato Peas, potato, brinjal, yam, cabbage, cauliflower Cabbage, garlic, spinach, brinjal, French bean, peas, okra Spinach, lettuce, Peas, bitter gourd, cucumber, okra, muskmelon, garlic Spinach, okra, French beans, cassava, cabbage, onion, carrot Garlic, peas, bitter gourd, cauliflower, okra, onion, brinjal
Table 3. Therapeutic properties of vegetables
Biological Compound Flavoniods ( Flavonones, flavones, flavonols, anthocynanis, catchins and biflavins): wide spread in vegetable crops
Therapeutic property Anti oxidants Stabilize the biological activity of ascorbic acid Anti-carcinogenic activity due to cellostatic activity Vitamin C Antioxidant Increases biomembrane stability Reduces hypercholesterolemia Caroteniods Reduce cancer risk by enhancing tumor surveillance by the immune system Ellagic acid Antimutagen Anticarcinogen Allicin, allistin, garlic, diallyl -Hypocholesterolaemic action disulphide, diallyl tirsulphide and -Antibacterial essential oils(onion and garlic) -antifungal Cheratin (bitter gourd) -Lower blood sugar Diosgenin( Yam) -Cortisone hormone -Contraceptive drugs Indoles (Cole crops) -Prevention of colon, rectum and breast cancer Dietary fiber (cellulose, hemi -Essential for bowel movement cellulose, lignin, gums, pectins and - Prevent appendicitis, colon mucilages cancer, diabetes, diverticulosis, - Gallstones, obesity - Gums and pectins owe to slower gastric emptying - Protects enzymes against degradation
Table 4. Recommended daily dietary allowances for Indians
Group
Particulars
Man
Sedentary work Moderate work Heavy work Sedentary work Moderate work Heavy work Pregnant woman Lactation 0-6months 6-12 months
Woman
Infants Children
Boy Girl Boy Girl Boy Girl
0-6months 6-12months 1-3years 4-6years 7-9years 10-12 years 10-12 years 13-15 years 13-15 years 16-18years 16-18years
Body wt. kg
Net energy Kcal/d
Protein g/day
Fat Calcium g/day mg/day
Iron mg/d
60
2425
60
20
400
28
50
2875 3800 1875
50
20
400
30
+15
30
1000
38
50
2225 2925
+25 +18
45
1000
30
+300 50 +550 +400 5.4 8.6 12.2 19.0 26.9 35.4 31.5 47.8 46.7 57.1 49.9
108/Kg 98/Kg 1240 1690 1950 2190 1970 2450 2060 2640 2060
2.05/Kg 1.65/Kg 22 30 41 54 57 70 65 78 63
500 25
400
22
600
22
600
22
500
12 18 26 34 19 41 28 50 30
Source: Nutrient requirements and recommended dietary allowances for Indians (1998), National Institute of Nutrition Hyderabad.
Table 5. Recommended daily vitamin vitamin requirement requirement for Indians
Group
Particulars
Retinol
ßcarotene
Thiamin
Ribofla vin mg/d
Nicotinc acid mg/d
Pyridoxin mg/d
Ascorbic acid ug/d
Folic acid ug/d
Vit.B12 ug/d
Man
Sedentary work Moderate work Heavy work Sedentary work Moderate work Heavy work Pregnant Woman Lactation 0-6 months 6-12 "
600
2400
1.2 1.4 1.6
1.4 1.6 1.9
16 18 21
2.0
40
100
1
600
2400
0.9
1.1
12
2.0
40
100
1
1.1
1.3
14
1.2
1.5
16 2.5
40
400
1
+0.2
+0.2
+2 2.5
80
150
1.5
Woman
2400 600 3800 950
+0.3 +0.2
+0.3 +0.2
+4 +3
Infants
0-6 months 6-12 months
350
1200
55ug/kg 50ug/kg
65ug/kg 60ug/kg
710ug/kg 650ug/kg
0.1 0.4
25
25
0.2
Children
400 400 600 600
1600 2400
0.7 1.0 1.2 1.3 1.2
8 11 13 15 13
40
1.6
40
30 40 60 70
0.2.1.0
2400
0.6 0.9 1.0 1.1 1.0
0.9 1.6
Boy Girl0
1-3 years 4-6 years 7-9years 10-12 years 10-12 years
Boy Girl
13-15 years 13-15 years
600
2400
1.2 1.0
1.5 1.2
16 14
2.0
40
100
0.2.1.0
Boy Girl
16-18 years 16-18years
600
2400
1.3 1.0
1.6 1.2
17 14
2.0
40
100
0.2.1.0
0.2.1.0
