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India is the second largest producer of vegetables after China. Spectacular increase in vegetable production was envisaged in the country from 15 million metric tonnes during 1950 to 204.83 million metric tonnes from an area of 11.35 million ha at present. India also ranks second after China in manually produced hybrid seeds of different vegetable crops. Productivity of different vegetable crops has been enhanced markedly during the last 60 years mostly due to genetic improvement and availability of improved varieties and hybrids of different vegetable crops. Advanced production and protection technologies also helped in enhancing the productivity. The first part of the book "Genetics and Advance Breeding Methods of Vegetable Crops" has been structured with 17 chapters detailing history of vegetable breeding, origin and domestication, reproductive features and pollination control mechanisms, general breeding methods for sexually and asexually propagated crops, breeding for high temperature stress, disease resistance and product quality, heterosis breeding, mutation breeding, breeding through alteration of ploidy, ideotype breeding, procedure for release of a variety, intellectual property rights and biotechnological approaches for vegetable breeding.

History of plant breeding The process of plant breeding takes care of changing or modifying the genetically controlled characters of a particular variety or genotype of a crop. The practice of age-old agriculture uses the process of selection from the existing variability to save a particular quality of seed to grow better crops in the next harvest. Gregor Mendel who is known as the father of Genetics discovered the law of segregation in the middle of the 1800s. This theory forms the base for the process of plant breeding. The primitive ways used for plant breeding are very different than what modern technology has contributed to the process of plant breeding during the 20th century. Plant breeding is the science and art of purposeful manipulation of characters of crop species to create new varieties with a set of desired characteristics. Significance of plant breeding has been highlighted especially after the “Green Revolution”.

History of Agriculture Cultivation of crops is one of the oldest occupations of mankind and probably began when it was discovered that certain seeds spilled on disturbed ground, grew in some mysterious way into new plants. The seeds were then collected and spread into different regions. This is how origin and introduction of crop plants started. Development of agriculture about 12,000 to13,000 years ago changed the way humans lived. They switched from nomadic hunter-gatherer lifestyles to permanent settlements and farming. However, scientists are unable to explain why man took so long to discover agriculture. Agriculture began independently in different parts of the globe and included a diverse range of taxa. At least eleven separate regions of the Old and New world were involved as independent centers of origin however, there was no single factor or combination of factors that led people to try farming in different parts of the world. Farming could have been brought on by climate changes at the end of the last ice age that favoured different annual plants like wild cereals to grow. But whatever the reasons for its independent origins, farming sowed the seeds for the modern age. Archeological evidence for the origin of crops points to mountainous areas of both Old World (Asia, Europe and Africa) and New World (North and South America), which have pronounced wet and dry seasons. Under such climatic conditions seeds would need to germinate, grow quickly with the onset of rains, complete their reproductive cycles and go to seed formation before summer sets in such as we see in annual plants.

Mode of reproduction All the living organisms produce individuls of their own kind for the survival of their species which is called reproduction. Hence, reproduction is the biological process by which new individual organism (offspring) are produced from their “parents”. In vegetable crops, modes of reproduction may be sexual, asexual and both. Most of the vegetable crops viz., tomato, brinjal, chilli, sweet pepper, peas, cowpea, hyacinth bean, French bean, cluster bean, runner bean, fenugreek, lettuce, cabbage, cauliflower, knolkhol, Brussels sprouts, sprouting broccoli, radish, beet, turnip, carrot, onion, leek, amaranth, palak, spinach, asparagus, pumpkin, bottle gourd, watermelon, muskmelon, ridge gourd, snake gourd, wax gourd, summer squash, bitter gourd, cucumber, sweet corn, coriander, parsnip, etc. are exclusively propagated sexually for both commercial cultivation and breeding purpose. Some vegetable crops like, pointed gourd, teasle gourd, yam, taro, Jerusalem artichoke, globe artichoke, etc. are exclusively propagated through asexual mode of reproduction. On the other hand, some vegetable crops like, potato, sweet potato, cassava, annual moringa, etc. can be propagated by both sexual and asexual modes of reproduction however, they are generally propagated asexually for commercial cultivation and their sexual reproduction is employed for the purpose of breeding.

Male-sterility Normal development of the male reproductive organ (stamen) and male gametophyte (pollen grain) is essential for successful completion of sexual reproduction in angiosperms. Abnormalities at any stage of stamen and pollen development can result in male sterility. Male sterility in plants implies the inability to produce or to release functional pollen. Male sterility is caused due to failure in the formation or development of functional stamens, microspores or gametes and /or release of pollens from the anther. Male-sterility can result from mutations in nuclear genes alone or mitochondrial genes or mitochondrial genes coupled with nuclear genes. The resulting conditions are known as genic male sterility (GMS), cytoplasmic male sterility (CMS) and cytoplasmic-genic male sterility (CGMS), respectively. Classification of male-sterility 1. Genetic male-sterility This male-sterility is caused due to mutations in nuclear genes alone or mitochondrial genes or mitochondrial genes coupled with nuclear genes which results abnormalities at any stage of stamen and pollen development.

Plant breeding is the purposeful manipulation of characters in plants to create new genotype with a set of desired characters. Hence, it may basically be referred to as designed manipulation of the heritable variation for the character concerned. Living organisms possess the remarkable capacity to convert the non-living materials into living staff, which results in movement, growth, metabolism and reproduction, and thus continuity of living organisms from one generation to the next is accomplished. The continuity of life through transmission of characters is the subject of the study of heredity, while the resemblances and differences between individuals of the same or different generations is the concern of the study of variation. These two universal processes of continuity and of change, which are referred to as “Heredity” and “Variation” are primary consequences of all organisms. Organized study of these two biological processes is the science of Genetics. Plant breeding, which may be termed as evolution of plant type directed by the will of mankind, is basically the process of selection of character(s) from heritable variation. Desirable heritable variations can also be induced through some genetic consequences like, hybridization, segregation, mutation, changing the number of chromosomes, etc. So frame of plant breeding lay on three basics:

Vegetable breeding is the purposeful genetic manipulation of qualities in vegetable crops to create new varieties with a set of desired characteristics that are better suited for cultivation, give better yield, quality and are resistant to biotic and abiotic stresses. Vegetable breeding can be accomplished through many different techniques ranging from plant introduction, simply selecting plants with desirable characteristics, to more complex molecular techniques. Classical plant breeding includes hybridization followed by selection and mutation to develop the desirable plant types. With the advancements in genetics, molecular biology and in vitro culture, different molecular genetics tools are also being used in vegetable breeding. Sexually propagated vegetable crops 1. Plant Introduction The term “Plant introduction” describes the movement of crop plants, species, varieties, wild species, etc. from their original growing sites to other locations where it was not grown earlier. Plant introduction is essentially the method of cultivating crop plants in a new environments. The agro-climatic conditions can differ greatly depending on the origin of the plant species and the area where they are introduced. Plant introduction is a time-honored strategy for improving crop diversity.

Mutation breeding is a method that uses physical radiation or chemical means to induce genetic variation in plants to develop new crop varieties. Mutation can be defined as a sudden heritable change in the character of an organism which is not due to either segregation or recombination. Mutation is the source of most genetic variation and the motor of evolution. It is a natural process, which occurs spontaneously and slowly over generations in plants, animals and all living beings. It involves alteration of their DNA, leading to the development of changes within the organism. Mutation may be sped up through the treatment of physical or chemical mutagens to achieve alteration in characteristics that are useful for the development of new variety of a plant species. Spontaneous mutations Spontaneous mutations are the net result of all that can go wrong with DNA during the life cycle of an organism (Glickman et al., 1986). Thus, the types and amounts of spontaneous mutations produced are the resultant of all the cellular processes that are mutagenic and those that are anti-mutagenic. Spontaneous mutations occur naturally without any apparent cause however, there are two possible sources of origin of these mutations.

The term genome refers to a complete set of DNA, including all of its genes. Each genome contains all of the information needed to build and maintain that organism. In the nucleus of each cell, the DNA molecule is packaged into thread like structures called chromosomes and each species has specific chromosome number. Most of the plants are diploid and they show in each one of its body cell, twice the number of haploid chromosomes (n) found in the gametes. There are two main types of chromosomal variation that involve changes in the number. These are euploidy (in Greek “eu”means true or even and “ploid”means unit), which involves the variation of whole sets of chromosomes and aneuploidy(“aneu” means uneven), where a single chromosome within a set varies. This variation may be either increase or decrease in the chromosome number. The euploids include diploid (2n), triploid (3n), tetraploid (4n), hexaploid (6n) or even higher degree of polyploidy. Polyploidy, thus involves more than two genomes and is, therefore, a genometic mutation involving increase in the dose of whole genome. This condition of polyploidy is more common in angiosperms.

The effect of inbreeding and outbreeding was found in ancient time in animals and human beings since civilization. Hence, the phenomenon “Heterosis” was conceived since pre-Mendelian era. But in plants this phenomenon was recognized only 200 years ago. Koelreuter (1766) first published his scientific investigation on hybridization. Knight (1799) first recorded increased vigour following crossing. Mendel (1865) also observed increased vigour in pea hybrids. Charles Darwin (1876) suggested that cross-fertilization was beneficial whereas self-fertilization was injurious. However, the scientific concept of heterosis phenomenon was established in post-Mendellian era by the monumental work by East (1908) and Shull (1908). General concepts of Heterosis • Heterosis is the widely occurring genetically governed biological phenomenon involving both plants and animals. • It frequently occurs in plants and is found mostly in cross-pollinated plant species than in self-pollinated plants. • It is built in evolutionary mechanism favouring better survival of heterozygotes in nature.

In the changing Global scenario, food, nutrition, healthcare and livelihood security are the matter of great concern to human, social and economic development. The global community is increasingly looking towards finding means of sustainable nutrition for the growing population across all countries. The emphasis is on identifying lowresource strategies acceptable to the communities that do not put an unnecessary burden on the environment (FAO, 1993). Nutritional security denotes the consumption and equitable access to adequate quantities of healthy, safe, affordable and nutritious food by every member of the family essential for optimal health and well-being. Concern for improvement of nutritional quality of vegetables has arisen in the context of providing nutritional security to our everincreasing population because poor nutrition is linked with increased risk of obesity, diabetes, and heart disease as well as broader impacts including higher health care costs and decreased productivity. More than 1.0 billion people globally are hungry due to food insecurity problem and about 3.0 billion people are malnourished due to poor nutrition causing mainly micronutrient deficiency.

Vegetable crops are highly susceptible to biotic stresses incited by different diseasecausing micro-organisms (fungi, bacteria, phytoplasma, virus), insect pests, nematodes, arachnids and weeds. In contrast to abiotic stresses caused by the environmental factors such as drought, heat, soil salinity, alkalinity, etc., biotic stress-causing agents directly deprive their host of its nutrients leading to reduced plant vigour and, in extreme cases, death of the host plant. In vegetable crops, different biotic stresses are the major cause of pre- and post-harvest losses. Indiscriminate use of chemicals for the control of diseases, insect pests and nematodes has several disadvantages particularly, increasing cost involved in chemical control, residual toxicity of the chemicals (fungicides, antibiotics, insecticides) in food chain and development of resistance against pathogens and insect pests to different chemicals. Management of diseases and insect pests involve the use of resistant varieties and integration of cultural and chemical control measures.

Basic concepts of plant stress, acclimation and adaptation Energy is the absolute requirement for the maintenance of structural organization over the lifetime of the organism. Maintenance of such complex structural organization over time requires a constant flow of energy through all biological organisms, which provides the dynamic driving force for the performance of important maintenance processes (the processes which are essential for an organism to remain alive and continue as the species) such as respiration, assimilation, nutrition, cellular biosyntheses and transport to maintain its characteristic structure and organization as well as the capacity to replicate and grow. Maintenance of such steady-state results in a meta-stable condition called homeostasis. Thus, “Homeostasis” is defined as a selfregulating process by which a living organism can maintain internal stability while adjusting to changing external conditions. It is the state of balance among all the living systems needed for the organism to survive and function properly. Plant stress Any change in the surrounding environment may disrupt homeostasis. Environmental modulation of homeostasis may be defined as biological stress. Thus, plant stress implies some adverse effect on the physiology of a plant induced upon a sudden transition from some optimal environmental condition where homeostasis is maintained to some suboptimal condition which disrupts this initial homeostatic state.

High temperature stress Abiotic stresses either individually or in combination cause morphological, physiological, biochemical and molecular changes that adversely affect plant growth and ultimately yield. The major forms of abiotic stress plants are exposed to in nature are heat, drought, cold and salinity. Of these abiotic stresses, heat stress has an independent mode of action on the physiology and metabolism of plant cells. High temperatures above optimal have generally damaging effects on plant development which has led to the prediction that Global warming have a negative effect on plant growth. High temperature regimes may cause severe yield reduction leading to even famine. High temperature stress has wide range of effects on plant in terms of physiology, biochemistry and gene regulation pathways. The susceptibility to high temperatures in plants varies with the stage of plant development and genotype. Mechanisms of heat tolerance Heat tolerance is generally defined as the ability of the plant to grow and produce economic yield under high temperature conditions. Several plant physiological parameters and mechanisms that contribute to heat tolerance in the field include:

Concept of Ideotype breeding In the breeding programme, elite crop varieties are developed through combination of relatively low-frequency alleles which are of known agronomic / horticultural importance (Lyu et al., 2013). During breeding programme, these elite varieties are developed targeting different main objectives, such as yield, product quality, resistance to abiotic and biotic stresses and agronomic suitability. A crop ideotype is defined as an idealised structural model, combining both morphological and physiological traits, with the potential to maximise yield and quality within a defined environment (Donald, 1968). Ideotype generally include factors that increase the survivability of the plant such as drought resistance, resource use efficiency, root architecture and disease resistance (Arraiano et al., 2006; Rezzouk et al., 2022). Definition of “Ideotype” may be broadened through combination of morphological and physiological traits (or their genetic bases) conferring to satisfying adaptation of a crop to a particular biophysical environment, crop management and end use.

Introduction Improved varieties, hybrids and quality seeds are considered as the basic and key inputs for the development of agriculture and horticulture. High quality seed production has been the major concern in the Indian sub-continent till 1960s. Before that, India was mostly dependent on USA for food grain. After 1960, Government of India established State Agricultural Universities in different states following “Land grant model” of USA, different ICAR Research institutes and All India Coordinated Crop Research Projects in a systematic manner to give the boost to develop large number of improved varieties with assured seed quality in all major agricultural and horticultural crops. The ultimate intention was to introduce the newly developed high yielding varieties for broad spectrum cultivation in the area of their adoption. Importance of variety and system of its release There are several ways and means to increase the crop production and productivity, however using genetically pure and high-quality seed is first and prime objective in agriculture/ horticulture. Govt. of India acknowledged seed as an essential commodity under essential commodities Act, 1955.

Intellectual Property Rights (IPR) There are two types of properties viz., i) Tangible, physical or material property and ii) Intangible or intellectual property. Intellectual property (IP) pertains to any original creation of the human intellect such as artistic, literary, technical or scientific creation. The tangible or physical properties are protected by the laws of land. In contrast, intellectual property is an idea, a formula, an invention, a design, a variety, etc. which= may give rise to a useful product. For obvious reasons the inventors would like to be rewarded and their inventions be protected from imitation. Such a right of an inventor to obtain economic benefit and protection of the invention from imitation is known as Intellectual Property Right (IPR). Thus, Intellectual property rights (IPR) refers to the legal rights given to the inventor or creator to protect his invention or creation for a certain period of time (Singh, 2008). Why Intellectual Property needs to be protected? Intellectual property rights (IPR) encourage innovation and protect the rights of the inventors in legalized form. It is an inevitable tool in today’s globalized economy. The invention of such things would require intellectual capacity, innovativeness and creative ability of the concerned person(s).

Old and Modern biotechnology Agriculture has evolved since the dawn of human civilization, first as a means to guarantee food supply and then, as a source of family income and improved profitability. Domestication of plants and animals that were found in the wild combined with gradual, long-term changes in their quality and quantity were the first signs of what is now collectively termed “Agriculture”. At that time, agriculture replaced the former nomadic habit of food collection for immediate consumption. Domestication of plants and animals, followed by food storage, coincided most probably unintentionally, with the growth of microorganisms. Thus, was born the classical food fermentation, the earliest known application of biotechnology, focusing on the use of microorganisms to produce food products. Gradual improvements in agricultural techniques, domestication of additional plant and species from the wild, step-by-step selection of better performing and more adapted genotypes, along with intuitive breeding continued at a slow pace. Mendel’s discoveries and laws revolutionized genetics, and led at the beginning of the 20th century, to planned and controlled breeding experiments. Breeding or the “old biotechnology” was harnessed as a most successful tool, resulting in better crops and farm animals, and “Green Revolution” of the 1960s was achieved. Many achievements are still being successfully implemented since then.

Origin, domestication and adaptation in India Tomato was classified under Lycopersicon for several years although, initially Linnaeus (1753) classified it in the genus Solanum. Recently, molecular studies provided new data on the relationships of tomato-potato and based on these results, tomato has been again assigned to the genus Solanum. Solanum section Lycopersicon includes the cultivated tomato (Solanum lycopersicum) and its wild relatives, Solanum lycopersicum being the only domesticated species. The wild cherry tomato, Solanum lycopersicum var cerasiforme, the ancestor of the modern cultivated tomato has been originated in Peru-Ecuador-Bolivia region of the Andes. The Veracruz-Puebla region of Mexico is the centre of domestication of the cultivated tomato. From Mexico, tomato was taken to Italy, Spain, Portugal and other European countries, Africa and Middle East by the explorers in the 16th century. It was taken to Philippines after its discovery by Magellan in 1521, and from there it was taken to other Asian countries. Tomatoes did not have an easy passage even in Europe. The fruit got tagged as the “poison apple” in Britain, France, Spain and other European countries. Tomato moved to the USA from northern Europe around 1781 where it was first grown by Thomas Jefferson in Virginia.

Brinjal is the fifth most economically important Solanaceous crop after potato, tomato, chilli, and tobacco. Apart from the well-known brinjal species (Solanum melongena L.), two other under-utilized species, the scarlet eggplant (S. aethiopicum L.) and the gboma eggplant S. macrocarpon are also cultivated. Brinjal, also known as aubergine or eggplant, under the family Solanaceae (Chromosome No.: 2n = 2x =24) is one of th important vegetables of the tropical countries particularly India, Bangladesh, Pakistan, China, Japan, Indonesia, Thiland, Malaysia and the Philippines. Brinjal is the most common, popular and principal vegetable crop grown widely in India for its various shape, size and colour of fruits. Brinjals are rich sources of potential antioxidants: anthocyanin and phenolic compounds. Origin, domestication and adaptation in India Brinjal (Solanum melongena) is believed to have been originated in Indo-Burma region and perhaps China is the secondary centre of origin of this crop. Various data indicate, that from the several species that evolved in Africa, one (S. insanum), gave rise to a distinct species which spread to South-East Asia as the wild ancestor of S. melongena (Lester 1998; Ranil et al., 2017). This wild progenitor of the cultivated species has wide distribution in at least 10 habitats in India which amply suggests India being the centre of origin of brinjal.

Chilli or hot pepper, the Capsicum species (principally Capsicum annuum) under the family Solanaceae (Chromosome No. 2n =2x =24) is a tropical vegetable-cum spice crop commonly used throughout the world as spice for its pungency and red colour of ripe dried fruits and also for its green fruits for pungency and flavour. Origin, domestication and adaptation in India It is generally accepted that the Capsicum genus belonging to the family Solanaceae was originated in Bolivia which consists of 25–30 species. Five of these Capsicum species viz., C. annuum, C. baccatum, C. chinense, C. frutescens, and C. pubescens were domesticated. The largest group of varieties is found under C. annuum which is grown worldwide. Both hot pepper and sweet pepper belonging to the same species Capsicum annuum originated from the wild and weedy Capsicum annuum var. minimum distributed from the southern United States to the northern South America. The primary centre of origin of chilli is in southern and central America and secondar centre in Guatemala.

Sweet pepper or bell pepper, a cultivar group of the species Capsicum annuum under the family Solanaceae (Chromosome No. 2n =2x =24) is grown worldwide as green vegetable for its thick and fleshy fruits having delicate taste, pleasant flavour and colour. Sweet pepper requires slightly cooler climate than hot chillies. The fruits are generally non-pungent hence, it is commonly known as sweet pepper. It is also popular as bell pepper because of blocky fruit shape. China is the largest producer of sweet pepper in the world. Origin, domestication and adaptation in India Hot chillies and sweet pepper have originated from the wild and weedy species Capsicum annuum var. minimum whose domestication occurred in Mexico and distributed from the southern United states to northern south America. Domestication, cultivation and human selection brought about changes in fruit size and shape and fruit position from erect to pendant. It also resulted in more self-pollinating character due to inserted stigma unlike the exserted stigma in the wild types.

Potato, Solanum tuberosum L. under the family Solanaceae (Chromosome No. 2n = 4x = 48) is the world’s most important vegetable crop and the fourth most important food crop after rice, wheat and maize. They contain a wealth of health benefits that make them essential as a staple dietary item for much of the world’s population. It is valuable both as a fresh product and as a processed product, and the current trend is for rapid growth in processed forms, mainly chips and French fries. It is now grown in nearly 150 countries. It is extensively cultivated in China, Russia, Ukarine, Poland, Ireland, Great Britain, Germany, Netherlands, France, Spain, South America, India and USA. Origin, domestication and adaptation in India Potato is a native of tropical South American region where it grows wild in nature and presents the widest diversity of forms like, tuber shape, size, colour, taste, etc. Cultivated diploid potatoes are believed to have originated in the high plateau region of Peru and Bolivia in South America, more specifically the Lake Titicaca basin in the Peru-Bolivian region (Simmonds, 1976).

Sweet potato, Ipomoea batatas under the family Convolvulaceae (Chromosome No. 2n = 6x = 90) is an important tuber crop grown mostly in tropical and subtropical regions of Asia, Latin America, the Pacific islands, Papua New Guinea and Africa. India and China are the leading sweet potato growing countries in the world. In India, it is largely grown in Uttar Pradesh, Bihar, Odisha, Madhya Pradesh, Maharashtra, Tamil Nadu, Kerala, Karnataka and Andhra Pradesh. Its large, swollen, starchy, sweet-tasting, adventitious roots are used as tuberous vegetable. Orange-fleshed sweet potato, in particular, with high β carotene content has become a prominent example of the effectiveness of biofortified staple crops to combat vitamin A deficiency. Sweet potatoes are rich in dietary fibers and are also known for improving gut health and digestion. It also contains a high amount of phytosterol that has a protective effect on the digestive system. Sometimes, tender leaves and shoots are consumed as a green leafy vegetable. Sweet potato tubers are used in agro-industry for the preparation of starch, alcohol and animal feed. Origin, domestication and adaptation in India Sweet potato has probably been originated between the Yucatán Peninsula of Mexico and the mouth of the Orinoco River in Venezuela.

Cauliflower Cauliflower, Brassica oleracea L var. botrytis under the family Brassicaceae (Cruciferae) having chromosome No. 2n = 2x =18 is the most popular vegetable among the cole crops, particularly in Asia. It is grown in all continents of the world,= of which Asia is the leading one followed by Europe and covers small acerages in North America, South America, Africa, Australia and New Zealand. India and China together have about 60 % of total cauliflower area of the world. Cauliflower is used in different curry and fry preparations with potato, garden pea, sweet pepper and other vegetables. It contains high quality proteins and good in stability of vitamin C after cooking. Frozen products are also prepared from cauliflower. It is rich in minerals such as potassium, sodium, iron, phosphorus, calcium, magnesium, etc. Origin, domestication and adaptation in India The cole crops have originated from the wild diploid species Brassica oleracea var. sylvestris mainly by mutation, human selection and adaptation. This wild species, a leafy kale-like plant which occurs in the northern shore of the Mediterranean Sea an along the lime cliffs in north-eastern England and North Sea is the progenitor of th cultivated kale and leafy non-heading cabbage. Probably kale was the first cole crop to have selected and adapted by man. From this leafy kale-like plant (Brassica oleracea var. sylvestris), other cole crops viz., kale, collard, broccoli, cauliflower and cabbage have been descended.

Onion, Allium cepa under the family Alliaceae (Amarylidaceae) having chromosome No. = 2n × 2x = 16 is an important vegetable cum spice crop grown in almost all parts of the world. The four major onion growing countries in the world are China, India, USA and Turkey. Other important onion growing countries are Iran, Italy, Egypt, The Netherlands, Russia, Thailand, Indonesia, Korea, Japan and Brazil. Onions are the fundamental ingredient in many dishes of the Asian countries. In India, important onion growing states are Maharashtra, Karnataka, Tamil Nadu, Andhra Pradesh, Gujarat, Punjab, Haryana, Rajasthan, Uttar Pradesh, Bihar and Madhya Pradesh. In India, onions are cooked for the preparation of stews, curries and as a base for rice pilafs or pilau or used fresh as salads. Onions are widely used in American cuisine, from burgers and sandwiches to soups and stews. Fried onion rings are a popular side dish. Onions are healthy whether consumed as raw or cooked however, raw onions have higher levels of organic sulfur compounds that provide many health benefits. Origin, domestication and adaptation in India The geographic origin of the onion is uncertain because the wild onion is extinct andancient records of using onions span western and eastern Asia. However, it is presumed that domestication of onion likely took place in Southwest or Central Asia comprising Iran, Afganistan, western Pakistan Tadzhikistan and Uzbekistan. Its secondary centre of origin is in the Mediterranean region. Its cultivation has spread in Western Asia from Palestine to India. It entered northern Europe through Italy and north Africa during 500 AD. It was introduced in the USA by the early Spanish explorers around 1625 AD.

Carrot, Daucus carota L. under the family Apiaceae (Umbelliferae) having chromosome numbers 2n = 2x = 18 is a root vegetable, grown in spring, summer and autumn in temperate regions and during winter in tropical and sub-tropical regions all over the world. It is important root crop of the European countries, USA, China, Japan, Korea and India. It is grown in almost all parts of India, both in plains and hills. Most of the carrots are typically orange in colour, though purple, black, red, white and yellow cultivars are also available. It is consumed fresh as salad or cooked as vegetable. It is also used for fresh juice, pickles and for the preparation of sweets. Leaves are used as fodder. Essential oil from the seeds is used for flavouring liquors and foods. It contains highest amount of β carotene (pro-vitamin A) among the common vegetables. It is also a good source of vitamin K, and vitamin B6. Origin, domestication and adaptation in India Carrot probably originated in Afghanistanin, the region where the Himalaya and Hindukush mountains are confluent. The secondary centres of diversity are probably Ehiopia and north America. Its domestication occurred in Afganistan and adjacent regions of Russia, Iran (previously called Persia), India, Pakistan and Anatolia (Van der Vossen and Sambas, 1993). From its centre of origin in Afghanistan, it was taken by the Arabs to eastern Mediterranean and Spain in 12th century. It was introduced in China in 13th or 14th century, in England during 15th century, in Japan in early 17th century and in the USA in 1620 AD.

Radish, Raphanus sativus under the family Brassicaceae (Crucifereae) having chromosome No. 2n = 2x =18 is grown mainly for fleshy taproot roots in both tropical and temperate regions throughout the world. Radish is cultivated widely in China, Japan, Korea, India, Europe and USA. It is grown throughout India and particularly in Uttar Pradesh, Bihar, West Bengal, Punjab, Haryana, Himachal Pradesh, Assam and Gujarat. Radish is mostly eaten raw as a crunchy salad or cooked as a vegetable. Leaves are sometimes eaten as cooked leafy vegetable. Immature pods of rat-tail radish, Raphanus sativus var. caudatus are also consumed as vegetable. Origin, domestication and adaptation in India Radish, one of the ancient root vegetables was domesticated in Asia prior to Roman times. Varieties of radish are now broadly distributed around the world, but almost no archeological records are available to help determine their early history and domestication. However, different research works have tentatively located the origin of Raphanus sativus in Southeast Asia, as this is the only region where truly wild forms have been discovered. This radish might be Oriental or Asiatic radish. India, Central China, and Central Asia appear to have been the secondary centers where different forms were developed. However, according to other hypothesis, eastern Mediterranean region, China and middle Asia are considered to be the origin of radish where wild radish still exists.

Garden pea, Pisum sativum var. hortense under the family Fabaceae (Leguminosae) having chromosome No. 2n = 2x = 14 is an all-time favourite vegetable in the world. As a cool season crop, it is extensively grown in early spring season in temperate zone and winter season in the tropics and subtropics. The immature/green peas are used as fresh vegetable as well as frozen or canned. Green peas are quite nutritious and contain high amount of protein and a fair amount of vitamin C, zinc, fibre and antioxidants. Diet containing green pea may improve the functionality of the gut. Origin, domestication and adaptation in India Discovery of the carbonized pea seed remains indicated that the smooth-seeded field pea was cultivated in the Near East and Europe as early as 7000 B. C. The earliest archaeological finds of peas come from Neolithic Syria, Turkey and Jordan. In Egypt, evidence of peas dates from ca. 4800–4400 BC. The wild pea was restricted to the Mediterranean basin and the Near East. Central Asia (Kazakhstan, Uzbekistan, Tazikistan, Turkmenistan, Kyrgyzstan, Afghanistan), Abyssinia (Ethiopia) and the Mediterranean basin are the primary centres of origin of pea with the near-east (Syria, Lebanon, Israel, Jordon) as the secondary centre of origin. In another view, Pisum is considered to have been originated in Ethiopia and from where it spread during prehistoric times to Mediterranean region, Central Europe, the Near East and subsequently to rest of the world. The wild progenitor of Pisum sativum is unknown.

French bean, Phaseolus vulgaris under the family Fabaceae (Leguminosae) and having chromosome No.2n = 2x = 22 is an important leguminous vegetable crop grown worldwide for its tender fruit (pod) as vegetable and dry seeds as pulse. French beans are unique among plant foods due to their high protein content. It is a highly variable species that has a long history of cultivation. Most of the bean varieties for processing (canned, frozen, and freeze-dried) are round podded, while fresh market cultivars are often flat or oval shaped. French bean is a valuable source of the amino acids lysine and tryptophan; minerals likes, iron, copper and zinc; and beneficial phytochemicals, antioxidants and flavonoids. Origin, domestication and adaptation in India French bean is thought to have been originated in South and Central America. Southern Mexico and Central America are considered to be the primary centre of origin, while secondary centres lies in Peru-Bolivia-Ecuador region of American continent. It was actually domesticated in Mesoamerica first and travelled south, probably along with squash (Cucurbita species) and maize. Multi-locus sequence data have indicated that the domestication of common bean was initiated 8000 years ago. Cultivation of French beans started by the American Indian tribes settled in Tehuacan Valley of Mexico and in Callejon de Huaylas, Peru. When Christopher Columbus returned from his second voyage to the New World in the year 1493 he brought French beans with him in the Mediterranean region. French beans were considered to be rare to find and expensive but soon became one of the commonly used beans in the 19th century. In France, French beans were introduced in the year 1597 by the Conquistador (Spanish explorers). In Europe, the French bean spread rapidly in the 16th and 17th centuries and reached England by 1594.

Cowpea, Vigna unguiculata under the family Fabaceae (Leguminosae) and having chromosome no. 2n = 2x =22 is in cultivation from ancient times in the tropics of old world. Cowpea is grown for green edible pods, immature seeds, dry grains and edible leaves as leafy greens. The immature pods and seeds as well as dry seeds besides being widely used as fresh vegetable and pulse are also frozen and canned. Immature pods are good source of protein, fibre, minerals, calcium and vitamins particularly vitamin A, B and C. It covers large areas in South Asia including India, Bangladesh, Pakistan, Myanmar and Sri Lanka besides Southeast Asian countries, like Indonesia, Malaysia, Thailand and Philippines. It is also grown extensively in Brazil and other countries of Latin America. In Africa, it is commonly eaten as a pulse along with sorghum and millets while in India it is used both as pulse and vegetable almost throughout the country. Cowpea is also grown for hay or forage and green manure crop. Origin, domestication and adaptation in India Cowpea is one of the most ancient human food sources and has probably been used as a crop plant since Neolithic times. All evidence points to its originating in Africa because of the presence of conspecific wild forms, although where the crop was first domesticated is uncertain. Among the African countries, Ethiopia, Central and South Africa and West Africa are considered to be the probable centre of origin. Although, there is no archaeological evidence for early cowpea cultivation in the centre of diversity, there was early consensus regarding West Africa being the centre of origin and place of early domestication. However, later research using molecular markers has suggested that domestication may have instead occurred in East Africa and currently both the theories carry equal weight.

Dolichos bean or Hyacinth bean, Lablab purpureus (L).Sweet. (Syn. Dolichos lablab Roxb.) under the family Fabaceae (Leguminosae) and having Chromosome No.: 2n = 2x = 22 is one of the most ancient among the cultivated plants. Young, immature pods are cooked and eaten like green beans. It is grown throughout the tropical regions of Asia, Africa and America. In India, it is grown extensively in the cool season in Tamil Nadu, Andhra Pradesh, Karnataka, Madhya Pradesh, West Bengal and Maharashtra. The pods are one of the rich sources of protein and it also provides fair amount of carbohydrates, calcium, phosphorus sodium, magnesium and iron, b-carotene, riboflavin, thiamine and nicotinic acid. Origin, domestication and adaptation in India Dolichos bean or Hyacinth bean has been originated in India as wild forms of this bean are found in this country. From India, it was introduced to China, Western Asia, Egypt and other tropical countries of South and South-east Asia and Africa. Vegetable and pulse type dolichos bean belong to two distinct botanical varieties under Lablab purpureus viz., Lablab purpureus var. typicus and Lablab purpureus var. lignosus, respectively. Various forms and cultivars of both the cultivated types are available in India.

The genus Amaranthus is rather unique in having species which are used for vegetable, grain and ornamental purposes. Vegetable amaranth, Amaranthus spp. under the family Amaranthaceae (Chromosome No.: 2n = 2x = 32, 34) is the most common tropical leafy vegetable in Southeast Asian countries especially India, Malaysia, Indonesia, southern China and hot and humid regions of Africa. It is an excellent source of β carotene, vitamin C, iron, calcium, potassium, magnesium, phosphorus, folic acid and dietary fibre. Its protein content (20-38% based on dry matter) includes methionine and other sulphur-containing amino acids. It is cultivated throughout India however, it is a common leafy vegetable in southern states viz., Tamil Nadu, Kerala, Karnataka, Telangana and Andhra Pradesh. Origin, domestication and adaptation in India The phylogenetic relationship and taxonomic delimitation in the genus Amaranthus under the family Amaranthaceae are still not resolved with extreme clarity. Phylogenetic analysis revealed clear separation of vegetable and grain amaranths. The derivation of grain and vegetable amaranths represent two lines of descent from the weed progenitor. Amaranthus hybridus L. This species has spread to different tropical countries like Mexico, Thailand, Malaysia, Indonesia and the Philippines. Amaranthus is a cosmopolitan genus of annual or short-lived perennial plants collectively known as amaranths. Vegetable amaranth is the most common leafy vegetable crop grown in India. Several kinds of vegetable amaranths under the genus Amaranthus and belonging to different species are grown in India.

Palak or spinach beet or beet leaf, Beta vulgaris var bengalensis under the family Amaranthaceae (previously under Chenopodiaceae) (Chromosome No. 2n = 2x = 18) is one of the most common leafy vegetables of the tropical and subtropical regions of the world. Its tender, soft and succulent leaves are used as a leafy vegetable. It is a rich and cheap source of β carotene, iron, essential amino acids, ascorbic acid, thiamine, riboflavin, pyridoxine, minerals like, calcium, iron, phosphorus, magnesium, potassium and zinc and fibre. It is very common vegetable in India, particularly in eastern and northern plains of Uttar Pradesh, Bihar, West Bengal, Rajasthan, Punjab and Haryana. It is also grown in Maharashtra, Gujarat and Madhya Pradesh however, it is not common in southern states. Origin, domestication and adaptation in India Palak originated from Indo-Chinese region. The Romans used this crop as food for humans and animals. The crop was introduced to USA in 1800 AD (Campbell, 1976). However, it is not known when it was introduced into India. Mentioning of palak in the medical treatise, Charak Samhita, c. 600 BC is the testimony of its long history of cultivation in India. Perhaps it was first cultivated in Bengal. In India, earlier improvement through natural selection by the farmers might have been in the direction of larger succulent leaves, late bolters and ability for regeneration after repeated cuttings. However, despite such a long history of cultivation genetic variability recorded in this species is not wide enough, commensurate with outcrossing breeding behaviour.

Okra, Abelmoschus esculentus under the family Malvaceae (Chromosome No.: 2n 126, 130, 132, 144) is an important vegetable in the tropical and sub-tropical parts of the world. Okra is mainly used for its tender green fruits as vegetable in many countries. In India, tender fruits are used as fried and boiled or in curry and sambar. It is also frozen, dehydrated and canned. Tender fruit contains appreciably high potassium, vitamin B, vitamin C, folic acid and calcium. It is a popular vegetable crop of low in calories and high in dietary fibre and protein contents, rich in essential amino acids, lysine and tryptophan. Origin, domestication and adaptation in India Okra has been regarded as of African origin. Perhaps it has been originated in Ethiopia and upper Nile region of Sudan. However, according to Zeven and Zhukovsky (1975), the genus Abelmoschus is considered to be of Asiatic origin. In fact, its cytotaxonomy confused that Abelmoschus might be of Asiatic origin and at least part of the cultigen. Joshi and Hardas (1976) believed that either the cultigen might have originated in Asia or it was present in Africa and India as a polyphyletic species. Significant native diversity of okra and its allied species in India points towards its secondary diversity here. Indian geneticists and cytologists reported that the wild relative A. tuberculatus which grows wild in India is one of the ancestors of cultivated okra, A. esculentus which is considered to be a natural amphidiploid species. Okra has been mentioned in ancient Sanskrit literature in the name “tindisha” and “gandhamula” which indicated very old association of this genus and its different species with India.

Muskmelon, Cucumis melo under the family Cucurbitaceae (Chromosome number: 2n = 2× = 24) is a highly relished crop because of its attractive flavour, sweet taste and refreshing effect. It is an important crop of Africa, Middle East, Asia, Southeast Asia, Japan, USA, South and Central America, France, Spain, Israel and many eastern European countries. Mature fruits are eaten fresh as a dessert fruit, canned or used for syrup or jam. Muskmelon is quite rich in ß carotene, vitamin B9, vitamin C and minerals like potassium and low in calorie content. Origin, domestication and adaptation in India The genus Cucumis, which includes cucumber (Cucumis sativus) and melon (Cucumis melo), has numerous wild African species, and it has therefore been assumed that melon originated in tropical Africa in eastern region, south of Sahara Desert. This proposition is supported by the presence of true wild melons which can still be found in some African countries. Some botanists consider melons native to the Levant and Egypt, while others place their origin in Iran, India, Afghanistan or Central Asia. Sebastian et al (2010) reported that the wild progenitor of C. melo occurs in India, and they confirmed that the Southeast Asian Cucumis hystrix is the closest relative of cucumber and most surprisingly, the closest relative of melon, Cucumis picrocarpus was from Australia. The wild forms of muskmelon reported from India are feral escapes derived from local cultivars.

Cucumber, Cucumis sativus under the family Cucurbitaceae (Chromosome No: 2n = 2× =14) is grown throughout the world for consumption of fresh and tender fruits as slicing cucumber, and for pickles as pickling cucumber. Slicing cucumbers are usually larger and have thicker skins, while pickling cucumbers are usually smaller and have thinner skins. The flesh of cucumbers is rich vitamin C, and folic acid, fibre and a range of minerals including magnesium, molybdenum and potassium. Origin, domestication and adaptation in India The genus Cucumis, which includes cucumber (Cucumis sativus) and melon (Cucumis melo), has numerous wild African species, and it has therefore been assumed that melon originated in Africa. For cucumber, this seemed less likely because wild cucumbers exist in India and a closely related species, Cucumis hystrix is available in the Eastern Himalayas. Using DNA sequences from plastid and nuclear markers for some 100 Cucumis accessions from Africa, Australia, and Asia, Sebastian et al (2010) concluded that melon and cucumber are of Asian origin and have numerous previously overlooked species-level relatives in Australia and around the Indian Ocean.

Watermelon, Citrullus lanatus under the family Cucurbitaceae (Chromosome number: 2n = 2× = 22) is an important and popular summer season crop of the USA, Middle east, Japan, Africa and India. Watermelon is primarily consumed fresh for their sweet, juicy and slightly grainy flesh and are often eaten as desserts. Watermelon is actually a nutrient dense food. It provides high levels of vitamins, minerals, andantioxidants particularly lycopene and relatively low in calories. Origin, domestication and adaptation in India The origin of watermelon was in tropical Africa perhaps in Kalahari Desert, now in Botswana. The progenitor species, Citrullus colocynthis is endemic to Africa. Wide variation of this progenitor species is also found in Rajasthan and Gujarat in India. Wild watermelon seeds have been found in Uan Muhuggiag, a prehistoric site in Libya that dates to approximately 3500 BC. Watermelon was domesticated in Africa and later it was introduced in India. From India it spread to Near East and Asia. The watermelon which was domesticated in Egypt by 2000 BC were not the sweet modern variety. The fruit flesh of wild watermelons is watery, but typically hard-textured, pale-coloured and bland or bitter. The familiar sweet dessert watermelons, C. lanatus, featuring non-bitter, tender, well-coloured flesh have a narrow genetic base, suggesting that they originated from a series of selection events in a single ancestral population.

Pumpkin (Cucurbita moschata) Duch. ex Poir. and summer squash (Cucurbita pepo) under the family Cucurbitaceae (Chromosome No. 2n = 2× = 40) are important tropical vegetable crops grown all around the world. The term “squash” is generally employed to designate the forms of C. pepo for immature fruits, all baking cultivars of C. maxima and the cushaw-type cultivars of C. mixta whose matured fruits are consumed. The term “pumpkin” is normally applied to the edible fruit of Cucurbita moschata, C. maxima and C. argyrosperma utilized when ripe as boiled or cooked vegetable or in pie. However, pumpkin is mostly associated with Cucurbita moschata Duch. ex Poir. Pumpkin cultivars are generally more tolerant to hot, humid weather than cultivars of C. maxima or C. pepo. It is extensively cultivated in India, Africa, Latin America, Southern Asia and United States. Among the five  domesticated cucurbita species, C. moschata, C. pepo and C. maxima are economically most important and among them summer squash, C. pepo is the most important in the world. However, of the different species of Cucurbita, pumpkin (C. moschata) is the most popular and grown throughout India. Pumpkin fruits are rich in ß carotene, flavonoid, polyphenolic antioxidants such as lutein, xanthin and different minerals viz., calcium, potassium and magnesium. Pumpkins help in keeping the heartbeat regular and blood pressure low. The fibre in pumpkin can also play a part in lowering blood pressure as well as cholesterol. Pumpkin occupies a prominent place among the vegetables owing to its high productivity, nutritive value, good storability, long period of availability and better transport potentialities.

Ridge gourd, Luffa acutangula and sponge gourd, Luffa cylindrica under the family Cucurbitaceae (Chromosome number: 2n = 2× = 26) is an important warm season fruit vegetable crop. Ridge gourd is widely cultivated in India, Southeast Asia, China, Japan, Egypt and other parts of Africa. Sponge gourd is now cultivated in all tropical regions of the world. It was an important crop used for industrial filters until World War II and Japan cultivated the best crop for this purpose. The main commercial production areas of sponge gourd today are China, Korea, India, Japan, Central America and Brazil. Immature fruits of ridge gourd and sponge gourd are eaten as a vegetable and at maturity both become very fibrous. The word luffa or ‘loofah’ is of Arabic origin and the sponge characteristic of the crop has been described in old Egyptian writings. Fruits are good sources of vitamin C, riboflavin, zinc and antioxidants. It is effective in balancing blood sugar levels, help eliminate toxic waste and prevent fat accumulation. Ridge gourd also helps reduce excessive body heat during summers which can prevent many ailments.  

Bitter gourd or Bitter melon, Momordica charantia L under the family Cucurbitaceae (Chromosome no. 2n = 2× = 22) is widely grown in India, Indonesia, Malaysia, Singapore, Thailand, China, Japan, East Africa, the Caribbean and South America for its edible fruit. Tender fruits are widely used as cooked vegetables in a number of ways. Bitter gourd is an excellent source of vitamin C, iron, magnesium, potassium, calcium and ß carotene. The fruits contain non-toxic glycoside momordicin, which gives it bitterness and also health benefits. It also contains an insulin-like compound called Polypeptide-p or p-insulin and steroidal compound “Charantin” having hypoglycemic property. Origin, domestication and adaptation in India Wild or semi-domesticated variants spread across Asia in prehistorical period, and it was probably domesticated in Southeast Asia. It has probably originated in eastern India or Indo-Burma area or southern China. Uncarbonized seed coat fragments have been tentatively identified from the spirit cave in northern Thailand however, there have been no archeological reports of bitter gourd remains in China (Marr et al, 2004).Population resequencing revealed the divergence between wild and South Asian cultivars about 6,000 years ago, followed by the separation of the Southeast Asian cultivars about 800 years ago, with the latter exhibiting more extreme trait divergence from wild progenitors and stronger signs of selection on fruit traits.

Bottle gourd, Lagenaria siceraria under the family Cucurbitaceae (Chromosome No: 2n = 2× = 22) is commonly grown vegetable crop of India, Africa, Central America and other warmer regions of the world. Tender fruits are widely used as cooked vegetables in a number of ways. Bottle gourd is a good source of vitamin C and zinc that may offer several skin benefits. It also contains minerals like calcium, magnesium, iron, and zinc. Its dietary fibre enhances gastro-intestinal health and promotes bowel movements and prevents constipation. Origin, domestication and adaptation in India It is the only crop known to have been cultivated in pre-Columbian times in both the Old and New World. Bottle gourd is indigenous to the tropical Africa. It has bihemispheric distribution in Africa, the old world and America, the new World. Its utilization by man is about 16,000 years in the Old World and 12,000 years in the New World. It was independently domesticated in the two hemispheres. It was one of the world’s first cultivated plants grown not primarily for food, but for the use of hardshelled fruit as containers. The apparent wild plant produces thinner-walled fruit that, when dried, would not endure the rigors of use on long journeys as a water container. Today’s bottle gourd may owe it’s tough, waterproof wall to selection pressures over its long history of domestication. The bottle gourd was theorized to have drifted across the Atlantic Ocean from Africa to South America.