**Abstract**

Legumes are one of the most valuable gifts of nature to man, animal, and environment. These are sustainable, affordable, water-efficient, and low-carbon footprint crop. Globally, the share of grain legume accessions is 15% of 7.4 million accessions conserved in genebanks, of which more than half of germplasm in genebanks are without characterization and evaluation data which ultimately limit the utilization of germplasm in legume improvement programs. Characterization of all genebank accessions should be of utmost priority for enhancing the utilization. The development of core, mini-core, reference sets, and trait-specific germplasm has provided route to crop breeders for mining genebanks. Identification of new sources of variation became easy with these subsets, but the entire collection also needs to be evaluated for unique and rare traits. In crop species with narrow genetic base, utilization of crop wild relatives as well as new resources aids to widen the genetic base of legume cultigens.

**Keywords:** core collection, crop wild relatives, diversity, genetic resources and legumes

### **1. Introduction**

One of the biggest challenges in the twenty-first century is to produce sufficient nutritious food in the face of climate change, population explosion, and rapid urbanization and to do so in an environmentally sustainable manner. The United Nations Sustainable Development Goal number 2 explicitly recognizes the pivotal role that genetic diversity plays for food security, nutrition, and sustainable agriculture. Legumes, together with cereals, played a prominent role to the development of modern agriculture. The legume family, Fabaceae, is the third largest family of flowering plants, with 946 genera and 24,505 species [1]. Few domesticated ones have incontestably proven to be of crucial nutritional value for both humans and animals due to their protein content, causing them to be recognized as the second most valuable plant source of nutrients [2]. Legumes are extensively distributed in diverse agroclimatic zones globally, from alpine and arctic regions to the equatorial tropics.

The peculiar characteristics of the family are taproot system; bipinnate leaves; flower with corolla, standard petal (1), wing petal (2), and keel (2) (**Figure 1**); and

#### **Figure 1.**

*Floral dissection of* papilionaceous *family (*Vigna vexillata*): (a) standard petal, (b) wing petal, and (c) keel petal.*


*a, number of species present globally; b, number of species present in India; c, percentage of species found in India. Source: [15].*

#### **Table 1.**

*List of important tribes with number of species.*

root nodules that facilitate nitrogen fixation in the soil. The family is divided into three subfamilies, namely, Caesalpinoideae, Mimosoideae, and Papilionoideae [3]. Among them, subfamily Papilionoideae is economically very important as it contains most of the commercial leguminous crops. Among pulse crops, *Lathyrus* and *Vicia* are the largest genus comprising 160 species, which are naturally distributed

**3**

*Legume Genetic Resources: Status and Opportunities for Sustainability*

**Sl. no. Botanical name Pulses Oilseeds Vegetable Seed** 

√

√

√

**spice**

√ √

√ √ √

√ √

√ √ √

√ √ √

√ √ √

√ √ √

√ √ √

√ √

√ √ √

√ √ √

√ √ √ √

**Root/ tuber**

√

**Forage**

√

√

√

√

√

√

*DOI: http://dx.doi.org/10.5772/intechopen.91777*

1 *Arachis hypogaea* L. (peanut)

2 *Cajanus cajan* (L.)

3 *Canavalia ensiformis*

5 *Codariocalyx motorius* (Houtt.) H. Ohashi (telegraph plant)

7 *Flemingia procumbens* Roxb. (Sohphlang)

8 *Glycine max* (L.) Merr. (soybean)

9 *Lablab purpureus* (L.)

10 *Lathyrus sativus* L. (grass pea)

11 *Lens culinaris* Medik. (lentil)

> *uniflorum* (Lam.) Verdc. (horse gram)

12 *Lupinus mutabilis* Sweet (tarwi)

14 *Medicago sativa* L. (lucerne)

15 *Melilotus indicus* (L.) All. (sweet clover)

16 *Periandra mediterranea* (Vell.) Taub. (sweet

tuber)

17 *Phaseolus lunatus* L. (lima bean)

18 *Phaseolus vulgaris* L. (common bean)

19 *Pisum sativum* L. (garden pea)

21 *Psoralea esculenta*

22 *Pueraria tuberosa*

Kudzu)

*tetragonolobus* (L.) DC. (winged bean)

Pursh (bread root)

(Willd.) DC. (Indian

20 *Psophocarpus* 

13 *Macrotyloma* 

Sweet (hyacinth bean)

4 *Cicer arietinum* L. (chickpea)

6 *Cyamopsis* 

Millsp. (pigeonpea)

(L.) DC. (jack bean)

*tetragonoloba* (L.) Taub. (cluster bean)


#### *Legume Genetic Resources: Status and Opportunities for Sustainability DOI: http://dx.doi.org/10.5772/intechopen.91777*

*Legume Crops - Prospects, Production and Uses*

**2**

*Source: [15].*

*List of important tribes with number of species.*

**Table 1.**

**Figure 1.**

*petal.*

root nodules that facilitate nitrogen fixation in the soil. The family is divided into three subfamilies, namely, Caesalpinoideae, Mimosoideae, and Papilionoideae [3]. Among them, subfamily Papilionoideae is economically very important as it contains most of the commercial leguminous crops. Among pulse crops, *Lathyrus* and *Vicia* are the largest genus comprising 160 species, which are naturally distributed

**S. no. Tribe Genus a/b/c Primary center of diversity** 1 Phaseoleae *Vigna* 107/26/24.3 Africa, Asia

*Floral dissection of* papilionaceous *family (*Vigna vexillata*): (a) standard petal, (b) wing petal, and (c) keel* 

2 Cicereae *Cicer* 44/5/8.8 Central Asia, Southwest Asia and

3 Fabeae *Lathyrus* 160/8/20 Europe, Asia and North America

*a, number of species present globally; b, number of species present in India; c, percentage of species found in India.* 

*Dolichos* 67/3/4.47 Africa, East Asia *Phaseolus* 50/3/6 America

*Macrotyloma* 25/4/6.25 Tropical Africa and Asia

*Cajanus* 32/16/50 South Africa, South East Asia, and East Africa

*Vicia* 160/15/10.6 Europe, Asia, and North America *Lens* 5/0/nil Mediterranean countries and Central Asia *Pisum* 3/0/nil Southern Europe, Mediterranean region, and

Mediterranean countries, and Himalayas

West Asia


#### **Table 2.**

*List of important legume crops having diversified importance.*

across temperate region of Europe, Asia, and America. *Vigna* has six subgenera. Ceratotropis is mostly referred to as Asiatic *Vigna*. Primary centers of diversity of major pulse genera are presented in **Table 1**.

Legumes play a major role in fulfilling human, animal food, and nutritional needs. The major grain legumes include dry beans, chickpea, cowpea, faba bean, lentil, field pea and pigeonpea, green gram, and black gram. Soybean and peanut are predominantly oil-producing legume. Beans, yard long bean, and garden pea where immature seeds and pods are eaten are vegetable types of legumes. Lucerne, berseem, grass pea, and cowpea are the forage legumes, while tuber legume includes zombi pea, winged bean, Sohphlang, etc. *Abrus precatorius* is having poisonous seeds which contain toxin *abrin.* In addition to these primary grain legumes, several underutilized potential legumes like cluster bean, horse gram, moth bean, and pillipsera, primarily grown in the Indian subcontinent, China, and South East Asia, are also equally important for ensuring food and nutritional security.

**5**

*\* Ref. [16]. \*\*Ref. [17].*

**Table 3.**

Bambara groundnut

*Legume Genetic Resources: Status and Opportunities for Sustainability*

Legumes are the reservoir of the protein, carbohydrate, fiber, and minerals. In addition to that, low glycemic index (GI) makes them super food that provides long-term health benefits. The isoflavone content of legumes plays a role in plant defense [4] and root nodulation and is also beneficial in human health. In addition to the human health, legumes also serve as fodder for livestock. The best advantage of legumes is nitrogen fixation, through which they enrich soil fertility and improve soil texture for other crops, and, hence, plays an important role in cropping system

Despite their significant contribution in global food and nutrition security, it has also been reported that their production rate becomes static mainly due to biotic factors like viruses, insects, parasitic weeds, nematodes, fungi, bacteria, and abiotic factors, viz., extreme temperatures, drought, flood, mineral imbalance, etc. [6, 7]. Therefore, there is a need to explore sustainable alternative strategies to improve

**Crop USDA NBPGR\*\* VIR CGIAR institutes SGSV\***

Chickpea 7000 14,626 15,246 20,764 47 Pigeonpea 4806 11,321 13,783 13,177 Green gram 3931 3935 856 8620 Pea 6161 4436 6113 11,929 Cowpea 1287 3671 1493 15,933 19,355 French bean 17,223 3919 42,314 Cluster bean 4051 61 Horse gram 2557 47

Zombi pea 32 1 460

Black gram 304 2200 220 363 Soybean 33,208 4779 4575 28,034 Grass pea 2613 4220 2537 Clovers 606 5152 — Lentil 2515 12,477 13,591 Faba bean 866 10,029 4154 Groundnut 13,406 15,622 14,583

Wild *Vigna* 565 1878 — Adzuki bean 187 1562

**ICARDA ICRISAT IITA**

2 1890 1528

[5]. Legumes with their economic use are presented as follows (**Table 2**).

*DOI: http://dx.doi.org/10.5772/intechopen.91777*

**2. Conservation**

Rice bean 2032

Lucerne 1748 230

*Legume germplasm holdings in major genebanks.*

*Legume Genetic Resources: Status and Opportunities for Sustainability DOI: http://dx.doi.org/10.5772/intechopen.91777*

Legumes are the reservoir of the protein, carbohydrate, fiber, and minerals. In addition to that, low glycemic index (GI) makes them super food that provides long-term health benefits. The isoflavone content of legumes plays a role in plant defense [4] and root nodulation and is also beneficial in human health. In addition to the human health, legumes also serve as fodder for livestock. The best advantage of legumes is nitrogen fixation, through which they enrich soil fertility and improve soil texture for other crops, and, hence, plays an important role in cropping system [5]. Legumes with their economic use are presented as follows (**Table 2**).
