**6. Major forage legumes of India**

#### **6.1. Egyptian clover (***Trifolium alexandrinum* **L.)**

The genus *Trifolium* from the tribe *Trifolieae* of the family Leguminosae (Fabaceae) is important for its agricultural value. A few of the 237 species of this large genus have actually been cultivated [26], out of which 25 species are important as cultivated and pasture crops [27]. Egyptian clover or berseem (*T. alexandrinum* 2n = 16) is commonly cultivated as winter annual in the tropical and subtropical regions. Berseem is popular due to its multicut [4–8] nature, providing fodder for a long duration (November to May), very high quantum of green fodder (85 t/ha) and better quality of fodder (20% crude protein), high digestibility (up to 65%) and palatability. Berseem was introduced in India from Egypt in 1904, and has been established as one of the best *Rabi* (winter season) fodder crop in entire North West Zone, Hill Zone and part of Central and Eastern Zone of the country, occupying more than two million hectare [28].

Berseem being an introduced crop in India, the most important drawback in genetic improvement has been the lack of genetic variability [29, 30]. Variability in the existing gene pool has been induced through mutation, polyploidization and inter-specific hybridization. High biomass production potential along with extended growth period and resistance to biotic stresses specially root rot and stem rot have been the main target traits that were to be improved genetically. Different genetic improvement programmes carried out in various research institutes/universities by utilizing breeding approaches like selection, polyploidy and mutation resulted in the development of >15 varieties for different berseem growing regions of India. Inter-specific hybridization have been used to improve resistance to biotic and abiotic stresses and extended length of the vegetative period because genes for wide scale adaptability are widely distributed in several wild species of *Trifolium* (**Table 3**). Interspecific hybrids of berseem with *Trifolium apertum* [31], *T. constantinopolitanum* [32], *T. resupinatum* [33] and *T. vesiculosum* [34] were successfully developed and progenies of interspecific hybrids showed introgression of various desirable traits, including late flowering and resistance to root rot and stem rot diseases.

**5. Problems associated with breeding of tropical forage legumes**

or intra-specific variation.

130 Forage Groups

million hectare [28].

**6. Major forage legumes of India**

**6.1. Egyptian clover (***Trifolium alexandrinum* **L.)**

Tropical forage legumes breeding programmes are associated with certain unique problems. Most of the tropical pasture legumes still possess traits of wild plants that include seed shattering, small seed size, seed dormancy, relatively slow germination rates, etc. In most of the cases we have very little knowledge about the basic biology of the species. Some of the problems include overlapping of vegetative and reproductive growth phases, uneven pod setting, nonsynchronous maturity and seed shattering in forage legumes [24]. Inherent heterozygosity as most forage species are cross pollinated. Self-incompatibility limits the extent to which they may be inbred; small floral parts make artificial hybridization tedious; poor seed producers; or produce seed with low viability as well as inherently low seedling vigor and competitive ability. Many forage species produce weak seedlings and stands are not easily established. Strains may perform differently with different systems of grazing management. Persistence of perennial tropical forage legumes is not as a single trait, but rather as a complex of traits dependent on various factors, such as diseases, insects, abiotic stresses, or management stress. Fertility barriers of one sort or another are very common in tropical forage legume breeding *viz*., berseem [25], owing to the wild nature of the species and inadequate knowledge of inter-

The genus *Trifolium* from the tribe *Trifolieae* of the family Leguminosae (Fabaceae) is important for its agricultural value. A few of the 237 species of this large genus have actually been cultivated [26], out of which 25 species are important as cultivated and pasture crops [27]. Egyptian clover or berseem (*T. alexandrinum* 2n = 16) is commonly cultivated as winter annual in the tropical and subtropical regions. Berseem is popular due to its multicut [4–8] nature, providing fodder for a long duration (November to May), very high quantum of green fodder (85 t/ha) and better quality of fodder (20% crude protein), high digestibility (up to 65%) and palatability. Berseem was introduced in India from Egypt in 1904, and has been established as one of the best *Rabi* (winter season) fodder crop in entire North West Zone, Hill Zone and part of Central and Eastern Zone of the country, occupying more than two

Berseem being an introduced crop in India, the most important drawback in genetic improvement has been the lack of genetic variability [29, 30]. Variability in the existing gene pool has been induced through mutation, polyploidization and inter-specific hybridization. High biomass production potential along with extended growth period and resistance to biotic stresses specially root rot and stem rot have been the main target traits that were to be improved genetically. Different genetic improvement programmes carried out in various research institutes/universities by utilizing breeding approaches like selection, polyploidy A major breakthrough in berseem breeding in India was achieved through induction of polyploidy. The work on polyploidization of berseem genome was started with the aim to induce greater leaf and stem size [35, 36]. Autotetraploid induced by using colchicine treatment, and selection at tetraploid level resulted in the development of first polyploid variety 'Pusa Giant' with more fodder production and good regeneration capacity, uniform and higher yield throughout the season than diploid varieties released for general cultivation in India [37]. Another big achievement in polyploidy breeding was achieved at IGFRI, Jhansi by developing an autotetraploid variety namely 'Bundel Berseem-3' through colchiploidy followed by recurrent single plant selection followed with mass selection [28]. Major success in Berseem breeding was achieved by induction of longer duration mutant in Mescavi variety through gamma ray treatment which resulted in 'BL-22' a variety released


**Table 3.** Desirable characters in berseem ecotypes and wild *Trifolium* species.

in 1988 for temperate and north west zone; and 'BL-180' released in 2006 for cultivation in north-west zone of India [28]. Protocol for in vitro plant regeneration from meristematic tissue and the establishment of regenerable callus culture have been developed in Berseem and related species viz., *Trifolium glomeratum*, *T. apertum*, *T. resupinatum* [38–40]. Embryo rescue technique has been effectively utilized to overcome the problems of post fertilization barriers in interspecific crosses of berseem with *Trifolium apertum*, *T. constantinopolitanum*, *T. resupinatum* and *T. vesiculosum* [31–34]. Recently, SSR based markers were developed for large scale utilization programme in Berseem [30]. Few studies on genetic diversity in Berseem and related *Trifolium* species were reported by using isozymes [29] and molecular markers [41].

(*S. hamata*, *S. scabra*, *S. humilis*, *S. viscosa* and *S. guianensis*) have been introduced primarily from Australia and evaluated at different sites in India [43–45]. This was in addition to the native perennial *S. fruticosa* Alston, which is widely distributed throughout the southern

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133

Testing and evaluation of wide germplasms carried out at IGFRI on acid and saline soil which contribute major part of the soils of India, indicated better adaptation of *S. hamata* and *S. seabrana* lines over other species in salinity. The potential of S*. seabrana* for tropical and subtropical regions of the country with clay and heavy soils, cool winters and distinct wet-dry seasonal conditions directed the use of this species in developing new breeding approach. The one could be based on the finding that it is the second progenitor of *S. scabra* which in turn elucidated the evolution of one of the most important *Stylosanthes* species, *S. scabra* may lead to important impacts on the efforts of improving *S. scabra* [47]. It may be possible to artificially synthesize *S. scabra* using pre-selected *S. viscosa* and *S. seabrana* accessions [48]. These artificial *S. scabra* genotypes could be used directly or more likely, be used in breeding programs. By doing so the genetic variation existing in the two diploid progenitor species would become available in improving the allotetraploid *S. scabra*. So far developed map and linked markers with anthracnose resistance also provide the opportunity to use them after converting them in sequence tagged sites (STS) or sequence characterized amplified region (SCAR) and then using them in direct breeding

Genus *Medicago* is one of the oldest forage legume comprising 60 perennial and 35 annual species, distributed mainly around the Mediterranean basin, cultivated throughout the world in diverse environments ranging both temperate and tropical environments [49]. It is generally agreed that the basic chromosome number for the genus *Medicago* are x = 7 and x = 8. Its ploidy varies from diploid (2n = 16) to polyploid (2n = 32, 48, 64). Perennial species are mainly tetraploids (2n = 4x = 32) and allogamous, however diploid (2n = 2x = 16) and hexaploid (2n = 6x = 48) cytotypes have also been reported [50]. *Medicago sativa* (alfalfa or lucerne) is widely cultivated as the most important forage legume in the temperate areas of the world. Lucerne is native to South West Asia as indicated by occurrence of wild types in the Cancasus and in mountainous region of Afghanistan, Iran. *M. sativa* complex, comprises of several members at the same ploidy level e.g., *M. falcata*, *M. media* and *M. glutinosa*, which

grown in Maharashtra, Gujarat, Andhra Pradesh, Karnataka, Tamil Nadu, Haryana, Madhya Pradesh, Rajasthan, Punjab. The major breeding objectives in the crop include vigorous tall growing plants, better branching, quick regeneration, and balance between seed and forage

Genetic resources for alfalfa improvement are limited and restricted to the *M. sativa* complex but tolerant sources for biotic and abiotic constraints are lacking in the complex [52].

or later generations [51]. In India, it is

peninsular regions [46].

programs.

**6.3. Alfalfa (***Medicago sativa* **L.)**

yield and persistence.

freely intercross, without any hybrid sterility in the F1

#### **6.2. Stylosanthes**

The genus *Stylosanthes* comprises approximately 40 species, distributed in the tropical [42], subtropical and temperate regions areas of America, Africa, and Southeast Asia. It can be grouped into two subgeneric sections, Stylosanthes and Stylosanthes. Most species are diploid (2n = 20) but polyploid species (2n = 40 and 2n = 60) also exist. Six species, namely *Stylosanthes scabra*, *S. seabrana*, *S. hamata*, *S. guianensis*, *S. humilis* and *S. viscosa*, are predominantly used as fodder legume in humid to semi-arid tropics of India (**Table 4**). These are very popular and have been widely adapted due to their ability to restore soil fertility, improve soil physical properties, and provide permanent vegetation cover as well as to provide nutritious fodder. The most specific problems associated with Stylosanthes are the limited variations of available germplasm and the susceptibility to anthracnose disease caused by the fungus *Colletotrichum gloeosporioides*. In the past, mainly five species of Stylosanthes


**Table 4.** Important *Stylosanthes* spp. with specific features.

(*S. hamata*, *S. scabra*, *S. humilis*, *S. viscosa* and *S. guianensis*) have been introduced primarily from Australia and evaluated at different sites in India [43–45]. This was in addition to the native perennial *S. fruticosa* Alston, which is widely distributed throughout the southern peninsular regions [46].

Testing and evaluation of wide germplasms carried out at IGFRI on acid and saline soil which contribute major part of the soils of India, indicated better adaptation of *S. hamata* and *S. seabrana* lines over other species in salinity. The potential of S*. seabrana* for tropical and subtropical regions of the country with clay and heavy soils, cool winters and distinct wet-dry seasonal conditions directed the use of this species in developing new breeding approach. The one could be based on the finding that it is the second progenitor of *S. scabra* which in turn elucidated the evolution of one of the most important *Stylosanthes* species, *S. scabra* may lead to important impacts on the efforts of improving *S. scabra* [47]. It may be possible to artificially synthesize *S. scabra* using pre-selected *S. viscosa* and *S. seabrana* accessions [48]. These artificial *S. scabra* genotypes could be used directly or more likely, be used in breeding programs. By doing so the genetic variation existing in the two diploid progenitor species would become available in improving the allotetraploid *S. scabra*. So far developed map and linked markers with anthracnose resistance also provide the opportunity to use them after converting them in sequence tagged sites (STS) or sequence characterized amplified region (SCAR) and then using them in direct breeding programs.

#### **6.3. Alfalfa (***Medicago sativa* **L.)**

in 1988 for temperate and north west zone; and 'BL-180' released in 2006 for cultivation in north-west zone of India [28]. Protocol for in vitro plant regeneration from meristematic tissue and the establishment of regenerable callus culture have been developed in Berseem and related species viz., *Trifolium glomeratum*, *T. apertum*, *T. resupinatum* [38–40]. Embryo rescue technique has been effectively utilized to overcome the problems of post fertilization barriers in interspecific crosses of berseem with *Trifolium apertum*, *T. constantinopolitanum*, *T. resupinatum* and *T. vesiculosum* [31–34]. Recently, SSR based markers were developed for large scale utilization programme in Berseem [30]. Few studies on genetic diversity in Berseem and related *Trifolium* species were reported by using isozymes [29] and molecular

The genus *Stylosanthes* comprises approximately 40 species, distributed in the tropical [42], subtropical and temperate regions areas of America, Africa, and Southeast Asia. It can be grouped into two subgeneric sections, Stylosanthes and Stylosanthes. Most species are diploid (2n = 20) but polyploid species (2n = 40 and 2n = 60) also exist. Six species, namely *Stylosanthes scabra*, *S. seabrana*, *S. hamata*, *S. guianensis*, *S. humilis* and *S. viscosa*, are predominantly used as fodder legume in humid to semi-arid tropics of India (**Table 4**). These are very popular and have been widely adapted due to their ability to restore soil fertility, improve soil physical properties, and provide permanent vegetation cover as well as to provide nutritious fodder. The most specific problems associated with Stylosanthes are the limited variations of available germplasm and the susceptibility to anthracnose disease caused by the fungus *Colletotrichum gloeosporioides*. In the past, mainly five species of Stylosanthes

*S. scabra* 2n = 4x = 40 Adapted in low rainfall areas (325 mm rainfall), suitable for semi-arid areas of

*S. viscosa* 2n = 2x = 20 Early emergence and highly stickiness of the leaves and stems, drought

properties

*S. fruticosa* 2n = 4x = 40 Allotetraploid, drought tolerant

**Table 4.** Important *Stylosanthes* spp. with specific features.

tolerant of Al and Mn

*S. viscosa* are known progenitor of *S. scabra*

*S. humilis* 2n = 2x = 20 Tolerance for salinity, susceptible to anthracnose, hairs on stems and leaves are

*S. guianensis* 2n = 2x = 20 Suitable for humid and higher rainfall regions, adapted to acid infertile soils,

(Curtis et al., 1995), highly palatable, grazing tolerant

Maharashtra, Andhra Pradesh, Karnataka and Tamil Nadu, *S. seabrana* and

Diploid *S. hamata* and *S. humilis* are the two progenitors of this species

tolerant, grows on poor soils, some resistance to anthracnose, acaricidal

some of the important features helpful in identifying the species

markers [41].

132 Forage Groups

**6.2. Stylosanthes**

**Species Chromosome Specific features**

2n = 4x = 40

*S. hamata* 2n = 2x = 20

Genus *Medicago* is one of the oldest forage legume comprising 60 perennial and 35 annual species, distributed mainly around the Mediterranean basin, cultivated throughout the world in diverse environments ranging both temperate and tropical environments [49]. It is generally agreed that the basic chromosome number for the genus *Medicago* are x = 7 and x = 8. Its ploidy varies from diploid (2n = 16) to polyploid (2n = 32, 48, 64). Perennial species are mainly tetraploids (2n = 4x = 32) and allogamous, however diploid (2n = 2x = 16) and hexaploid (2n = 6x = 48) cytotypes have also been reported [50]. *Medicago sativa* (alfalfa or lucerne) is widely cultivated as the most important forage legume in the temperate areas of the world. Lucerne is native to South West Asia as indicated by occurrence of wild types in the Cancasus and in mountainous region of Afghanistan, Iran. *M. sativa* complex, comprises of several members at the same ploidy level e.g., *M. falcata*, *M. media* and *M. glutinosa*, which freely intercross, without any hybrid sterility in the F1 or later generations [51]. In India, it is grown in Maharashtra, Gujarat, Andhra Pradesh, Karnataka, Tamil Nadu, Haryana, Madhya Pradesh, Rajasthan, Punjab. The major breeding objectives in the crop include vigorous tall growing plants, better branching, quick regeneration, and balance between seed and forage yield and persistence.

Genetic resources for alfalfa improvement are limited and restricted to the *M. sativa* complex but tolerant sources for biotic and abiotic constraints are lacking in the complex [52]. The annual and perennial species of the genus *Medicago* are the reservoir of several useful agronomic traits, including disease and insect resistance and potential salt and drought tolerance having direct implication in cultivated alfalfa improvement (**Table 5**). Most of the lucerne cultivars grown in the country and worldwide are susceptible to many diseases and insect pests and the most serious constraint is the alfalfa weevil (*Hypera postica* Gyll.) [53]. Resistance to weevil has been reported in several annual species such as *M. scutellata*, *M. prostrata*, *M. turbinata* and *M. intertexta* [54–57]. Genes conferring resistance to aphid have been identified in *M. rugosa*, *M. scutellata* and *M. littoralis* [58]. Similarly, three woody species *viz*. *M. arborea*, *M. strasseri* and *M. citrine* of the section *Dendrotelis* have been reported as excellent sources for incorporating drought and salt tolerance in *M. sativa* [59–61]. However, due to post fertilization barrier, interspecific hybridization is difficult, so we may need to use biotechnological tools like ovule-embryo culture and electroporation.

**Species Annual/**

*M. dzhawakhetica* Bordz.

*M. suffruticosa* Ram.

*M. cancellata* M.B.

*M. prostrata* Jacq.

*M. scutellata* (L.) Miller

*M. turbinata* (L.)

*M. intertexta* (L.)

All.

Miller

*M. littoralis Rohde* ex Lois

*M. arborea* Hutch.

*M. strasseri* Greuter et al.

*Medicago citrine* (*Font Quer*) Greuter

*M. truncatula* Gaertner

**perennial**

**Chromosome number (2n)**

Annual 30 Mediterranean

Annual — Mediterranean

Annual — Mediterranean

*M. lupulina* L Annual Excellent species for

Perennial 32 Mediterranean

Annual 16 Mediterranean

**Table 5.** Annual and perennial *Medicago* species and their desirable characters.

Annual 16 West

*M. rugosa Desr.* Annual 30 Mediterranean

*M. polymorpha* L Annual 14 Europe, North

Mediterranean region

Perennial — — Resistance to *Phoma* 

Perennial 48 Russia Resistance to *Stemphyllium*

Perennial Resistance to alfalfa weevil

Basin, Southern Ukraine

Mediterranean Basin

Basin, East Europe, Caucasus

Africa, Middle East, Ukraine, Georgia, Central Asia

Basin

Basin

region

Perennial 32 Crete Iceland Woody species, drought

Perennial 48 Balearic Islands Highly drought and salt

Russia

Basin, East Europe,

Perennial 32 Western

**Distribution Desirable traits References**

http://dx.doi.org/10.5772/intechopen.81186

Tropical Forage Legumes in India: Status and Scope for Sustaining Livestock Production

Cold tolerance and resistance to *Phoma medicaginis*

*medicaginis*, deep taproot system and high

and potato leafhopper

High biomass production, Resistance to alfalfa weevil

Resistance to alfalfa weevil [54, 56]

Resistance to alfalfa weevil [54, 57]

Resistance to aphid [58]

Plant height, high seed production potential

sustainable agriculture, reported to improve soil health, reduce diseases and

Woody species, ornamental value, drought and salt

tolerant species within the section *Dendrotelis*

Genes possessing broad spectrum resistance to anthracnose, stay green

save moisture

and salt tolerance

tolerant

genes

Resistance to aphid [58, 83]

palatability

leaf spot

and aphid

[81]

135

[81]

[82]

[54]

[83]

[83]

[59, 61]

[60]

[86]

[84, 85]

Inter specific hybrids of *M. sativa* with some of the perennial species viz. *M. cancellata*, *M. glomerata*, *M. papillosa*, *M. prostrata*, *M. rhodopea* and *M. saxatilis* have been recovered by conventional crosses [51]. However, pollen and embryological studies demonstrated that there exist strong post fertilization barriers for recovering hybrids between *M. sativa* and annual species [62]. Utilizing embryo culture and fertilized pod culture techniques interspecific hybrids were obtained between *M. sativa* and many other annual species however, no hybrids were produced between *M. sativa* and weevil resistant *M. scutellata* [63, 64]. Bauchan and Elgin [65] reported chromosomal incompatibility and presence of two SAT chromosomes in *M. scutellata* as the major barriers for getting interspecific hybrids between *M. sativa* and *M. scutellata*. Utilizing protoplast fusion technique S<sup>1</sup> plants were obtained between *M. sativa* and *M. rugosa* and it was confirmed by genomic *in situ* hybridization (GISH) that small portions of *M. rugosa* chromosomes were present in the hybrid however, it is not clear that in which chromosome the resistance genes are present [50].

A lot of molecular information has been generated across species. However, information from *M. truncatula* on marker-trait association is unlikely to be exploitable in lucerne, considering the large differences between annual and perennial [66]; in addition to the differences due to the ploidy level which may further contribute to the inconsistent genetic control of some morpho-physiological traits between the two species [67]. Some breeding goals such as region-specific adaptation; drought-tolerance; improvement for forage quality should be considered [68]. Attempts have been made to produce transgenic alfalfa containing fungal chitinase gene for resistance against fungal pathogens [69], tolerance to abiotic stresses such as salt and cold [70, 71], improved forage quality [72], and sulfur-containing amino acids [73], value addition by making it an edible forage vaccine [74]. In recent years the breeding strategies for Lucerne are more towards utilizing potential of polycross methods followed with phenotypic selection. It has resulted in development of a few cultivars in recent years. The future strategies should include development of cold and drought hardy lucerne with degree of persistence for pasture and meadows, increasing genetic base, high seed production, stress tolerance, diseases and pest resistance etc.


**Table 5.** Annual and perennial *Medicago* species and their desirable characters.

The annual and perennial species of the genus *Medicago* are the reservoir of several useful agronomic traits, including disease and insect resistance and potential salt and drought tolerance having direct implication in cultivated alfalfa improvement (**Table 5**). Most of the lucerne cultivars grown in the country and worldwide are susceptible to many diseases and insect pests and the most serious constraint is the alfalfa weevil (*Hypera postica* Gyll.) [53]. Resistance to weevil has been reported in several annual species such as *M. scutellata*, *M. prostrata*, *M. turbinata* and *M. intertexta* [54–57]. Genes conferring resistance to aphid have been identified in *M. rugosa*, *M. scutellata* and *M. littoralis* [58]. Similarly, three woody species *viz*. *M. arborea*, *M. strasseri* and *M. citrine* of the section *Dendrotelis* have been reported as excellent sources for incorporating drought and salt tolerance in *M. sativa* [59–61]. However, due to post fertilization barrier, interspecific hybridization is difficult, so we may need to use biotechnological tools like ovule-embryo culture and

Inter specific hybrids of *M. sativa* with some of the perennial species viz. *M. cancellata*, *M. glomerata*, *M. papillosa*, *M. prostrata*, *M. rhodopea* and *M. saxatilis* have been recovered by conventional crosses [51]. However, pollen and embryological studies demonstrated that there exist strong post fertilization barriers for recovering hybrids between *M. sativa* and annual species [62]. Utilizing embryo culture and fertilized pod culture techniques interspecific hybrids were obtained between *M. sativa* and many other annual species however, no hybrids were produced between *M. sativa* and weevil resistant *M. scutellata* [63, 64]. Bauchan and Elgin [65] reported chromosomal incompatibility and presence of two SAT chromosomes in *M. scutellata* as the major barriers for getting interspecific hybrids

obtained between *M. sativa* and *M. rugosa* and it was confirmed by genomic *in situ* hybridization (GISH) that small portions of *M. rugosa* chromosomes were present in the hybrid however, it is not clear that in which chromosome the resistance genes are present [50]. A lot of molecular information has been generated across species. However, information from *M. truncatula* on marker-trait association is unlikely to be exploitable in lucerne, considering the large differences between annual and perennial [66]; in addition to the differences due to the ploidy level which may further contribute to the inconsistent genetic control of some morpho-physiological traits between the two species [67]. Some breeding goals such as region-specific adaptation; drought-tolerance; improvement for forage quality should be considered [68]. Attempts have been made to produce transgenic alfalfa containing fungal chitinase gene for resistance against fungal pathogens [69], tolerance to abiotic stresses such as salt and cold [70, 71], improved forage quality [72], and sulfur-containing amino acids [73], value addition by making it an edible forage vaccine [74]. In recent years the breeding strategies for Lucerne are more towards utilizing potential of polycross methods followed with phenotypic selection. It has resulted in development of a few cultivars in recent years. The future strategies should include development of cold and drought hardy lucerne with degree of persistence for pasture and meadows, increasing genetic base, high seed production, stress tolerance, diseases

plants were

between *M. sativa* and *M. scutellata*. Utilizing protoplast fusion technique S<sup>1</sup>

electroporation.

134 Forage Groups

and pest resistance etc.

#### **6.4. Cowpea (***Vigna unguiculata* **(L.) Walpers)**

Cowpea (2n = 2x = 22, genome size = 620 Mb) also known as 'black eye pea' or 'hungryseason crop' is an annual food and forage crop mostly grown throughout the semi-arid tropics in parts of Asia, Africa, Southern Europe, Southern United States, and Central and South America (Singh 2005). It can be grown throughout the year due to its short duration and fast growing nature. It is suitable for inter, mixed and relay cropping system. Cultivated cowpea, which is in subspecies *unguiculata*, is divided into five cultivar groups namely *Unguiculata*, *Sesquipedalis* (yard-long-bean), *Textilis*, *Biflora* and *Melanophthalmus* [75]. The commonly cultivated cowpea belongs to cultivar group *Unguiculata* the most widespread and economically important group of the species. They are pulse and vegetable and forage types. Other cultivar group *Biflora* also known as 'catjang cowpea' mainly cultivated in South Asia (India, Sri Lanka) as a pulse or as forage for hay and silage, and as a green manure crop. In Australia and Asia cowpea is primarily a fodder crop, but is also used for green manure or as a cover crop [76]. In India, the crop is cultivated around 6.5 lakh ha with 3 lakh as fodder crop in Rajasthan, Gujarat, Maharashtra, Karnataka and Tamil Nadu [24].

**Author details**

Ajoy Kumar Roy

**References**

Tejveer Singh, Srinivasan Ramakrishnan\*, Sanat Kumar Mahanta, Vikas C. Tyagi and

Tropical Forage Legumes in India: Status and Scope for Sustaining Livestock Production

http://dx.doi.org/10.5772/intechopen.81186

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\*Address all correspondence to: srinivasmic@gmail.com

ICAR-Indian Grassland and Fodder Research Institute, Jhansi, India

Cowpea was first introduced to India 1000–1500 years ago and now Indian-subcontinent appears to be a secondary centre of diversity. In India a large numbers of varieties for vegetable, pulse and fodder purpose have been developed. The breeding objectives have focused around developing lines with terminal drought tolerance, early maturity, erect growth to fit in cropping systems and enabling improved radiation use efficiency, high harvest index and resistance to diseases. The desirable traits in forage cowpea varieties are leafiness with indeterminate growth to get green fodder for a longer period. International Institute of Tropical Agriculture (IITA) has developed several dual purpose cultivars of cowpea with high grain and biomass yields and erects habit for intercropping/mixed farming purposes. In future development of cowpea lines against various forms of root-knot nematode, cowpea aphids and *Fusarium* wilt, is required. Further, development of transgenic cowpea lines with resistance to major insect pests can also be a breakthrough in cowpea breeding.
