**3. Utilization**

For sustainable growth in agriculture production "Conservation through use" approach is the only way. Storing the genetic resources will not solve the purpose until it is utilized. In genebanks, genetic integrity is maintained over the periods with the aim to utilize this variability in the future and bring them to the mainstream breeding programs. More than 80% of genetic resources conserved in genebanks are without characterization and evaluation data. Huge collection size with large duplicates or triplicates is again a big constraint for systematic characterization and evaluation in multi-environment experiments. To tackle this situation, the concept of core collection [11] and mini-core collection [12] are considered as the best solution for characterization of samples that represent most of the variability of the germplasm collections. Core collection represents maximum genetic diversity with minimum repetitiveness of germplasm; hence, the size of germplasm became manageable without affecting the extent of genetic diversity of the germplasm (**Figure 2**).

A general procedure for the selection of a core collection can be divided into five steps, which are described in the following sections:

i.Identify the material (collection) that will be represented.

ii.Decide on the size of the core collection.

iii.Divide the set of material used into distinct groups.

iv.Decide on the number of entries per group.

v.Choose the entries from each group that will be included in the core.

Conventional core and mini-core collections have been developed in many legume crops. **Table 4** represents the core and mini-core developed in legumes.

Trait-specific reference set is also developed by various genebanks which offers huge opportunities to identify novel sources of variation for use in breeding program. Discovery of new traits is also possible during large-scale characterization program which resulted into unique genotypes for its further exploitation in breeding programs. For example, unique seed morphotype with extended funiculus was found during lentil characterization of 2600 accessions of lentil, and this trait is associated with fast water uptake [13].

**7**

**Table 4.**

*List of cores and mini-cores developed in legume crops.*

**Figure 2.**

*Legume Genetic Resources: Status and Opportunities for Sustainability*

*Field view of lentil characterization program at ICAR-NBPGR, India.*

**Sl. no. Crop Core/mini-core References** Soybean Core and mini-core [18–23] Peanut Core and mini-core [24–28] Chickpea Core and mini-core [12, 29, 30] Pigeonpea Core and mini-core [30, 31] Lentil Core [30, 32] Mungbean Core and mini-core [33, 34] Adzuki bean Core [35] Common bean Core [36–42] Cowpea Core [43] Moth bean Core [44] Pea Core [45] Hyacinth bean Core [46] *Medicago* spp. Core [47–49]

Crop wild relatives (CWR) are wild plant species genetically more or less closely related to a particular crop, but unlike the crop species has not been domesticated and remain untouched by humans. Being progenitors of crop, they contain enormous genetic variation, which are readily available to plant breeders to use in crop improvement programs and to meet the challenge of global food security along with enhancing agricultural production and sustainability in the context of a rapidly growing world population and accelerated climate change. CWRs can be categorized based on the genecology that explains the extent to which CWRs can exchange genes with the crop. The Taxon Group (TG) concept is as follows: TG1a comprises crop species; TG1b, the taxa within the same species as crop; TG2, taxa in the same series or section as crop; TG3, taxa within the same subgenus as crop; TG4, taxa

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

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

#### **Figure 2.** *Field view of lentil characterization program at ICAR-NBPGR, India.*


#### **Table 4.**

*Legume Crops - Prospects, Production and Uses*

become of utmost priority.

**3. Utilization**

plasm (**Figure 2**).

genebank in the world has been presented in **Table 3**.

steps, which are described in the following sections:

ii.Decide on the size of the core collection.

iv.Decide on the number of entries per group.

is associated with fast water uptake [13].

and diversify their production. For that, the use of diverse legume genetic resources in crop improvement is one of the most sustainable strategies and ways to conserve valuable genetic resources for the future. Crop improvement programs are always depending upon genetic diversity available in genebank. Globally, genebanks hold ~1 million accessions of leguminous crop. Legume germplasm conserved in major

A large number of genetic resources are conserved ex situ in genebanks; a considerable amount of diversity remains untapped in the nature. Hence it became a priority to collect maximum amount of diverse germplasm before it lasts forever. Crop wild relatives (CWR) are reservoir of genes for breeding [8–10]. To explore the potential of CWRs in today's changing climate, collection and conservation

For sustainable growth in agriculture production "Conservation through use" approach is the only way. Storing the genetic resources will not solve the purpose until it is utilized. In genebanks, genetic integrity is maintained over the periods with the aim to utilize this variability in the future and bring them to the mainstream breeding programs. More than 80% of genetic resources conserved in genebanks are without characterization and evaluation data. Huge collection size with large duplicates or triplicates is again a big constraint for systematic characterization and evaluation in multi-environment experiments. To tackle this situation, the concept of core collection [11] and mini-core collection [12] are considered as the best solution for characterization of samples that represent most of the variability of the germplasm collections. Core collection represents maximum genetic diversity with minimum repetitiveness of germplasm; hence, the size of germplasm became manageable without affecting the extent of genetic diversity of the germ-

A general procedure for the selection of a core collection can be divided into five

i.Identify the material (collection) that will be represented.

v.Choose the entries from each group that will be included in the core.

Conventional core and mini-core collections have been developed in many legume crops. **Table 4** represents the core and mini-core developed in legumes. Trait-specific reference set is also developed by various genebanks which offers huge opportunities to identify novel sources of variation for use in breeding program. Discovery of new traits is also possible during large-scale characterization program which resulted into unique genotypes for its further exploitation in breeding programs. For example, unique seed morphotype with extended funiculus was found during lentil characterization of 2600 accessions of lentil, and this trait

iii.Divide the set of material used into distinct groups.

**6**

*List of cores and mini-cores developed in legume crops.*

Crop wild relatives (CWR) are wild plant species genetically more or less closely related to a particular crop, but unlike the crop species has not been domesticated and remain untouched by humans. Being progenitors of crop, they contain enormous genetic variation, which are readily available to plant breeders to use in crop improvement programs and to meet the challenge of global food security along with enhancing agricultural production and sustainability in the context of a rapidly growing world population and accelerated climate change. CWRs can be categorized based on the genecology that explains the extent to which CWRs can exchange genes with the crop. The Taxon Group (TG) concept is as follows: TG1a comprises crop species; TG1b, the taxa within the same species as crop; TG2, taxa in the same series or section as crop; TG3, taxa within the same subgenus as crop; TG4, taxa


**9**

**Table 6.**

*Legume Genetic Resources: Status and Opportunities for Sustainability*

*C. echinospermum*, *C. pinnatifidum*, *C. bijugum*, *C. judaicum*, and

*C. pinnatifidum*, *C. bijugum*, *and* 

*V. aconitifolia*, *V. glabrascence*, *V. sublobata V. umbellate*

Cowpea *V. pubescence*, *V. vexillata*, *V. reticulata*, *V. oblongifolia*, *V. luteola*

*dekindtiana*

Pigeonpea *C. scarabaeoides*, *C. sericeus*,

*V. ambacensis*, *V. davyi*, *V. glabrescens*, *V. marina*, *V. mungo*, *V. oblongifolia*, *V. parkeri*, *V. racemosa*, *V. reticulata*, *V. vexillata*, and *V. unguiculata* subsp.

*C. acutifolius*, *C. lineatus*, *C. albicans*

**Crop Wild relative Trait Reference**

*C. judaicum*, *C. pinnatifidum* Gray mold resistance [60] *C. echinospermum Phytophthora* root rot [61]

resistant

*cajaninae*)

tolerance

resistance, salt tolerance

mosaic disease resistance, salt

cytoplasmic male sterility

*Phytophthora* blight resistance

mildew and *Ascochyta* blight

weevil, broomrape, powdery mildew, *Fusarium* wilt, root rot, *Ascochyta* blight and white wilt

*V. radiata var. sublobata* Bruchid resistant [62, 63] *V. luteola*, *V. trilobata* Salt stress resistant [64]

*V. mungo* var*. silvestris* Bruchid resistance [65]

*C. scarabaeoides*, *C. albicans* Pod wasp (*Tanaostigmodes* 

*C. acutifolius* Sterility mosaic disease

*C. cajanifolius* Nuclear male sterility,

Pea *P. fulvum* Pea weevil, rust, powdery

*Wild genetic resources as trait donor in few pulse crops [70–77].*

*C. sericeus* Cytoplasmic male sterility,

*P. sativum* subsp. *elatius* Resistant to nematodes,

*C. albicans* Pod borer resistance, sterility

(*Helicoverpa armigera)*

*Ascochyta* blight resistance [58, 59]

*Fusarium* wilt resistance [59, 60]

Cyst nematode [59]

Insects Resistance [65]

Resistance to *Striga gesnerioides* [66]

Pod fly (*Melanagromyza obtusa*) [67]

*Cercospora* leaf spot disease

(MYMV) resistance

[57]

[62]

[65]

[68]

[68]

[68]

[68]

[68]

[69]

[69]

Chickpea *C. microphyllum* Resistant to legume pod borer

Black gram *V. mungo* var. *silvestris* Mungbean yellow mosaic virus

within the same genus as crop; and TG5, different genus to the crop [8]. CWRs have been categorized into three gene pools as primary gene pool (GP1) contains close relatives that readily intercross with the crop. Secondary gene pool (GP2) contains

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

*C. montbretii*

*C. reticulatum*

Green gram

*C. bijugum*, *C. judaicum*, *C. pinnatifidum*, *C. reticulatum*, *C. echinospermum*, and *C. cuneatum*

#### **Table 5.**

*Gene pool of major legumes.*


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

*Legume Crops - Prospects, Production and Uses*

Lentil *L. culinaris*, *L. orientalis*, *L. tomentosus*

Cowpea *V. unguiculata* var*.* 

*V. radiata* var*. radiata*, *V. radiata* var. *sublobata*, *V. radiata* var*. setulosa*

*V. mungo* var. *mungo*, *V. mungo* var. *silvestris*

*unguiculata* (L.) Walp (cv. *unguiculata*, cv. *biflora*, cv. *sesquipedalis*, cv. *melanophthalmu*s, cv*. textilis*), *V. unguiculata* var. *spontanea* (Schweinf.), *V. unguiculata* subsp*. alba*, *V. unguiculata* subsp. *dekinditiana* (Harms.), *V. unguiculata* subsp. *pubescence*, *V. unguiculata* subsp. *stenophylla*, *V. unguiculata* subsp. *tenuis*

Faba bean *— V. narbonensis*,

Pigeonpea *C. cajanifolius C. lineatus*,

*V. angularis* var. *nipponensis* and wild

Rice bean *V. angularis V. dalzelliana*,

types of *V. umbellata*

Cluster bean

Green gram

Black gram

**Crop Gene pool References**

*C. senegalensis* — — [50]

*L. lamottei*, *L. odemensis*

*V. mungo* var. *mung0*, *V. mungo* var*. silvestris*, *V. aconitifolia*, *V. trilobata*

*V. radiata* var*. radiata*, *V. radiata* var. *sublobata*, *V. radiata* var. *setulosa*, *V. aconitifolia*, *V. trilobata*

*V. unguiculata* subsp. *aduensis*, *V. unguiculata* subsp. *baoulensis*, *V. unguiculata* subsp. *burundiensis*, *V. unguiculata* subsp. *letouzeyi*, *V. unguiculata* subsp. *pawekiae*

*V. hyaeniscyamus*, *V. galilaea*, *V. johannis*, *V. bithynic*

*C. sericeus*, *C. scarabaeoides*, *C. albicans*, *C. trinervius*, *C. reticulatus*, *C. confertiflorus*, *C. latisepalous*

*V. dalzelliana*, *V. glabrescence*, *V. minima*

*V. glabrescence*, *V. minima*

*C. pinnatifidum*, *C. bijugum*, *C. cumeatum*, *C. chorassanicum*, and *C. yamashitae*

*V. angularis*, *V dalzelliana*, *V. glabrescens*, *V. grandis*, *V. umbellata*, *V. vexillata*

*V. angularis*, *V. dalzelliana*, *V. glabrescens*, *V. grandis*, *V. umbellata*, *V. vexillata*

*C. platycarpus*, *C. lanceolatus*, *C. acutifolius*

*V. aconitifolia*, *V. mungo*,

*V. aconitifolia*, *V. mungo*,

*V. radiata*, *V. trilobata*, *V. grandis*

*V. radiata*, *V. trilobata*, *V. grandis*

*L. ervoides* [51]

[50]

[14, 52–55]

[14, 52, 53]

[55]

[56]

[57]

[14]

[14]

**GP1 GP2 GP3** Chickpea *C. reticulatum C. echinospermum C. judaicum*,

**8**

**Table 5.**

*Gene pool of major legumes.*

Adzuki bean

#### **Table 6.**

*Wild genetic resources as trait donor in few pulse crops [70–77].*

within the same genus as crop; and TG5, different genus to the crop [8]. CWRs have been categorized into three gene pools as primary gene pool (GP1) contains close relatives that readily intercross with the crop. Secondary gene pool (GP2) contains

all the biological species that can be crossed with the crop but where hybrids are usually sterile. Tertiary gene pool (GP3) comprises those species that can be crossed with the crop with difficulty and where gene transfer is only possible with radical techniques. Another way is taxonomic which is based on taxonomic relationship of CWR with the crop [12]. Gene pools of some of the major legumes are represented (**Table 5**).

CWRs have provided vital genetic diversity for crop improvement since the twentieth century. They imparted resistance to numerous pests and diseases and tolerance to many abiotic stresses, viz., extreme temperatures, drought, and flood, and to improve nutrition, flavor, color, texture, and yield stability [13]. Almost all modern varieties of crops contain one or more genes derived from a CWR and contributed significantly to the agricultural and horticultural industries and to the world economy [14]. Furthermore, being components of natural ecosystems, they also play a role in functioning and maintaining the ecosystem services. However, many of CWRs remain unexplored. To explore the unexplored potential of CWRs, collection, conservation, characterization, and evaluation are the only powerful ways. Some examples of the use of CWRs in providing resistance to abiotic and biotic stress yield and quality improvement are listed in **Table 6**.
