<div style="text-align:justify">Background: Genetically diverse parents give an increased chance of genetic recombination and superior expression of hybrid vigour. Mahalanobis D2 statistics is an important tool for calculating the amount of genetic diversity in the populations and for assessing the relative contribution of various components to the total genetic divergence. 
 
Methods: Thirty genotypes of mungbean [Vigna radiata (L.) Wilczek] were grown in a randomized block design with four replications at S.D.A.U., Gujarat during kharif, 2019 to study genetic diversity. By using Mahalanobis&rsquo;s D2 statistics, all possible 435 pairs of thirty genotypes were computed for ten characters. 
 
Result: D2 analysis indicated that material was genetically diverse. Twelve clusters were formed by dividing the genotypes. To become highly genetically diverse, the inter-cluster distance should be high (Distance between cluster XI and cluster IX; cluster XI and cluster X), which can be used for hybridization programme. Cluster X followed by cluster I found appropriate for within group hybridization due to the presence of most heterogeneous genotypes indicating high intra-cluster value. Cluster data revealed that genotypes in cluster X, cluster VIII and cluster IV had desirable traits for yield improvement. These clusters could be directly selected for breeding programme. Contribution to total divergence was higher from number of branches per plant, pod length and 100-seed weight.</div>

Estimation of Genetic Diversity in Mungbean [Vigna radiata (L.) Wilczek] Genotypes Grown in Gujarat

<div>Background: Faba bean (Vicia faba L.) is one of the oldest cool season food legume crops, stands next to soybean (Glycine max L.) and pea (Pisum sativum L.). A throughout knowledge of existing genetic variation among seed yield and its component traits is essential for developing high yielding varieties in faba bean. Realizing the importance of genetic diversity in key economic traits, the present investigation planned to assess the genetic diversity in faba bean germplasm for yield improvement in faba bean breeding programme.&nbsp; 
 
Methods: The experimental material comprised of 80 faba bean germplasm lines, grown in RBD with three replications at Research Farm of Department of Genetics and Plant Breeding, CCS Haryana Agricultural University, Hisar during Rabi 2015-16. The data on 10 quantitative traits was analysed for Mahalanobis D2 statistic, stepwise multiple regression and principle component analysis (PCA). 
 
Result: The present study has assessed the existed genetic variations traits among faba bean germplasm lines for seed yield and its component traits. This would certainly provide guidelines in the selection of parents as well as effective selection of promising faba bean genotypes in faba bean breeding programmes for developing high yielding varieties.</div>

<div>Diversity Analysis for Seed Yield and its Component Traits among Faba Bean (Vicia faba L.) Germplasm Lines</div>

<div style="text-align:justify">The present experiments were carried out at Department of Horticulture, Dr. PDKV, Akola and Regional Research Centre, Amravati during the years 2013-14 and 2014-15. Fifty five genotypes of cluster bean were assessed for genetic divergence&nbsp;using Mahalanobis D2 technique. Among the characters studied in all four environmental conditions, gum content in seed&nbsp;(63.50%), plant spread (17.17%), number of primary branches per plant (4.65%), days to first flower (3.77%), hundred&nbsp;seed weight (2.09%), days to 50 % flowering(1.95%), seed to husk ratio (1.68%) and ten dry pod weight (1.35%) contributed&nbsp;95 percent to the total divergence. Genotypes were grouped into 8 clusters using Tocher&rsquo;s method. Cluster V was the&nbsp;largest group, involving 17 genotypes followed by twelve genotypes were grouped in cluster IV, eleven genotypes in&nbsp;cluster III and six genotype each in cluster I and II. The remaining solitary clusters (VI, VII and VIII) contained only one&nbsp;genotype each. The genotypes from the solitary clusters showed high divergence and useful in breeding. The intra-cluster&nbsp;distance ranged from 0 to 9.15. Cluster V possessed the highest intra-cluster distance (D2=9.15), followed by cluster IV&nbsp;(D2=6.34), cluster III (D2=4.71), cluster II (D2=3.31), and cluster I (D2=2.65). The clusters comprised of only one genotype&nbsp;had zero intra-cluster distance (cluster VI to VIII). The average inter-cluster distance reveled&nbsp; the maximum divergence(D&sup2;)&nbsp;between cluster V and VIII (D&sup2;=37.26) followed by cluster III and V (D&sup2;=29.92), cluster VI and VIII (D&sup2;=25.51). On the&nbsp;basis of inter cluster distance and performance observed in the present study a breeding programme involving genotypes&nbsp;for a specific character has been selected using cluster mean.</div>

Genetic divergence studies in cluster bean genotypes

<div>Background: The genetic divergence analysis was done using Mahalanobis D2 statistics. The mean intra-cluster and inter-cluster D2 values are compared for drawing conclusions on superiority of cowpea genotypes for various plant yield and quality attributes. 
 
Methods: In the field of Vegetable Research Farm of Department of Horticulture, RPCAU, Pusa, Indiaduring 2018-19 (Rainy season) thirty-three cowpea genotypes were taken for genetic divergence analysis. The genotypes exhibited marked divergence and thus grouped into clusters following Tocher&rsquo;s method of clustering. The mean intra-cluster and inter-cluster D2 values among the clusters were compared for their superiority of yield and quality attributes.&nbsp; 
 
Result: All the selected genotypes displayed marked divergence. Among the five clusters, cluster I consisted eight, cluster II had three, cluster III had eleven, cluster IV had nine and cluster V had two genotypes. The clustering pattern had no parallelism between genetic diversity and geographical distribution, suggesting that the selection of parental genotypes for hybridization will be more appropriate based on genetic diversity. The intra-cluster D2 values ranged from 0.00 in cluster II, cluster III, cluster IV and cluster V to 16.12 in cluster I. The inter-cluster D2 values revealed that highest inter-cluster generalized distance (44.50) was between cluster V and cluster III, while it was the lowest (20.12) between cluster II and cluster I. From this study it can be concluded that for selection and heterotic recombinants emphasis may be given to attributes such as seed germination percentage, peduncle length and average pod weight to enhance the yield of cowpea. Similarly, with respect to the clusters for obtaining the heterotic recombinants, genotypes placed in cluster V, cluster II and cluster III may be used in the crossing program.&nbsp;</div>

Study of Genetic Divergence for Yield and Quality Traits in Cowpea [Vigna unguiculata (L.) Walp.]

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<div>Background: Clusterbean [Cyamopsis tetragonoloba (L.) Taub.] (2n=2x=14) is an under exploited legume belonging to family fabaceae. Clusterbean is a versatile legume crop cultivated mostly as animal feed, green manure green leaves as fodder, vegetable and cover crop. Clusterbean is a drought resistant, hardy, deep rooted annual legume crop. D2 statistics&nbsp; provides a measure of magnitude for divergence between two genotypes under comparison. For broadening the genetic base of cultivars, the genetic diversity present in cultivated and wild relatives must be explored. Generally, diverse germplasms are expected to give high hybrid vigor and hence, it necessitates studying genetic divergence among the existing varieties and genotypes for the identification of parents for hybridization programme. 
 
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<div>Methods: The present investigation was undertaken to study genetic variability in clusterbean [Cymopsis tetragonaloba (L.) Taub] with using a set of 40 genotypes at Agronomy Instructional Farm, Department of Agronomy, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar during Kharif 2019 in randomized block design with four replications. Mahalanobis (1928) D2 statistic was used for assessing the genetic divergence between different populations. Grouping of the genotypes in different clusters was done by using Tocher&rsquo;s method. The inter-cluster distance was calculated by measuring the distance between clusters I and cluster II, between clusters I and cluster III, between clusters II and cluster III and so on. Likewise, one by one cluster was taken and their distances from other clusters were calculated. 
 
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<div>Result: The genetic diversity analysis revealed the formation of nine clusters suggested the presence of considerable genetic diversity among the 40 genotypes. The clustering pattern indicated that geographic diversity was not associated with genetic diversity. The analysis of per cent contribution of various characters towards the expression of total genetic divergence indicated that, the&nbsp; number of branches per plant followed by gum content, days to maturity, days to flowering contributed maximum towards total genetic divergence. On the basis of inter cluster distances, cluster IX was found to be more divergent. Therefore, it was concluded that the genotypes belonging to these cluster should be inter crossed in order to generate more variability.</div>
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​Genetic Diversity for Seed Yield and its Components in Clusterbean [Cymopsis tetragonaloba (L.) Taub]

<div>Background: Rice (Oryza sativa L.) gets affected by more than seventy diseases by the infection of bacteria, fungi and viruses. Among, bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv oryzae (Xoo) is the important disease around the rice cultivated areas and causing drastic yield losses ranging between 20 and 30 per cent. Among very few options for increasing yield potential in rice, genetic diversity among the genotypes plays an important role in selection of parents having wider variability for disease resistance.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
 
Methods: The rice genotypes were screened using PDI for bacterial leaf blight (BLB) and subjected to D2 analysis for nine quantitative traits viz., plant height, number of productive tillers per plant, panicle length, days to fifty per cent flowering, number of grains per panicle, thousand grain weight, grain length, grain breadth and single plant yield.&nbsp; 
 
Result: On the basis of Mahalanobis D2 statistics, the thirty five genotypes are grouped into VIII clusters. The highest intra cluster distance was recorded for cluster II (41.16) followed by cluster VI (37.73). Out of thirty five genotypes screened under field condition using percentage disease index (PDI), CR 1009 found to be resistant with the lowest PDI value of 9.67 per cent. The genotypes Karsamba, TPS 4 and Kaivara samba registered highest PDI value of 70.67, 67.22 and 66.67 respectively. The BLB resistance in genotype dependent and not cluster based. The resistant genotype CR 1009 under field screening was positioned in VI cluster. The cluster II had susceptible genotypes karsamba and kaivarasamba. Thus, the identified genotypes can be utilized in recombination breeding to provide BLB resistance segregants.</div>

​​Genetic Diversity Analysis for Bacterial Leaf Blight Disease Resistance in Rice (Oryza sativa L.)

Background: JS335 is a leading variety of soybean in central India with high stability, but YMV susceptible. These leads to the incorporation of the YMV resistance in the elite genotypes of soybean variety JS335. 
 
Methods: 45 breeding lines obtained from a cross between two parents SL525 (YMV resistant) and JS335 (YMV susceptible) along with two parents and a check SL958 were analysed for diversity using Mahalanobis D2 and 19 polymorphic SSR markers. These lines were evaluated for yield and component traits and YMV, during 2020 at two locations viz. Ludhiana and Gurdaspur, India. 
 
Result: Diversity analysis based on Mahalanobis D2 statistics divided genotypes into five clusters. The maximum (288464.1) and minimum (15103.7) inter-cluster distance were observed between clusters 4 and 5 and clusters 2 and 5, respectively. SSR marker analysis grouped a total of 48 genotypes into three major clusters. The mean for agronomic traits of genotypes was categorised and SLJS 41-2 was found YMV resistant and exhibited a high yield (32.1 g/plant). The contribution of JS 335 towards SLJS 41-2 was found to be 62.5%. This line could further be tested at multilocation to evaluate adaptability and subjected to different yield trials for varietal release or used as a potential YMV donor.

Morphological and SSR Marker based Selection for an Elite YMV Resistant Breeding Line from a Segregating Population of Soybean [Glycine max (L.) Merrill]

<div>Background: Pigeonpea has remarkable contribution in flourishing the Indian agricultural economy but over the decades, its productivity has remained stagnant. Presence of genetic diversity in breeding population is the key to develop high yielding varieties. Therefore the current study was aimed to explore genetic divergence among pigeonpea genotypes. 
 
Methods: A set of 178 pigeonpea germplasm lines were evaluated in randomized block design to assess the genetic divergence and clustering pattern of pigeonpea genotypes. Observations on various yield component traits were recorded. For the estimation of the Fe and Zn content ICP-OES (Perkin Elmer USA) was used. Mahalanobis D2 analysis was carried out to assess the genetic divergence. 
 
Result: Wide range of genetic diversity was revealed among lines for eleven traits studied. Mahalanobis D2 analysis grouped all the genotypes into eleven non-overlapping clusters. The inter cluster D2 values indicated that cluster IV and XI (21046.45) were the most diverse and cluster V and cluster VII (60.67) were the less diverse. Out of the eleven characters studied days to maturity, plant height and yield per plot contributed 93.32 per cent of the total divergence. Based on mean performances, cluster XI and cluster II were found to be beneficial for early flowering and early maturity genotypes, cluster V and cluster VII for number of pods per plant and yield per plot, respectively. The highest mean value for grain iron and zinc content was recorded in cluster III rendering simultaneous improvement for these traits. Therefore, trait-wise selection of diverse parents from different clusters would be desirable and beneficial.</div>

Genetic Divergence for Seed Yield Enhancing and Quality Traits in Pigeonpea [Cajanus cajan (L.) Millsp.]

Background: The insight concerning genetic diversity and relationship among the rice genotypes is a basic contribution to the crop improvement programs. The present field experiment was conducted to study the level of diversity present in 47 rice genotypes using both morphological and molecular analysis. 
 
Methods: The experiment was carried out at Agricultural Research Farm, Banaras Hindu University, Varanasi (U.P.), during Kharif-2019 with 47 rice genotypes. Mahalanobis&rsquo; D2 analysis was carried out to evaluate the morphological diversity present among the genotypes and 24 polymorphic SSR markers were used for molecular analysis using the NTSYSpc software. 
 
Result: Mahalanobis&rsquo; D2 grouped 47 rice genotypes into 6 clusters based on the inter-se genetic distance. The highest inter-cluster distance (1134.14) was observed between clusters II and IV indicating the genotypes present in these clusters to be highly divergent. Molecular diversity analysis grouped the 47 rice genotypes into 3 main clusters i.e., cluster I, cluster II and cluster III, which were further divided into sub-clusters. Polymorphic Information Content varied from 0.12 to 0.86, with an average of 0.465. The highest PIC value was observed for locus RM 507 (0.86). All the 24 primers showed polymorphism and the number of alleles was common for all i.e., 2. Together, the morphological and molecular diversity analysis revealed that Desi Dhan and IR 91143-AC 293-1, Desi Dhan and BD 105, IR 85850 and Lal Sundiya, Chauli and Swarna were the most diverse genotypes among the 47 rice genotypes included in the study.

Morpho-molecular Diversity Analysis in Rice (Oryza sativa L.) Genotypes using Microsatellite Markers

<div>Background: Dolichos bean is an important leguminous vegetable having a wide range of variation in different quantitative characters. Assessing genetic diversity among dolichos bean accessions can ensure development of suitable high-yielding and adapted varieties with suitable maturity period.&nbsp; 
 
Methods: Fifteen genotypes were evaluated for different characters in Dolichos bean at two locations of Dr. Rajendra Prasad Central Agricultural University viz. Vegetable Research Farm, Pusa and Krishi Vigyan Kendra, Birauli, Samastipur, Bihar during the year 2018-19 and pooled data was analyzed. The genotypes were evaluated for genetic variability and genetic divergence for 14 characters. For the assessment of genetic diversity among the fifteen genotypes of dolichos bean, Mahalanobis (D2) statistic (Mahalanobis, 1936) was used, following the procedure given by Rao, 1952. Grouping of genotypes into clusters was done using Tocher&rsquo;s method as described by Rao, 1952. 
 
Result: Phenotypic Coefficient of Variation (PCV) was slightly higher than Genotypic Coefficient of Variation (GCV) for all the characters indicated that the characters were less influenced by environment. The characters having high heritability and high genetic advance include harvesting duration, number of pods per plant, pod length, pod diameter, individual pod weight, weight of seeds per pod, 100 fresh green seed weight, pod yield and percent incidence of yellow mosaic virus. Therefore, selection for above characters is highly effective. Genetic diversity analysis evaluated that all genotypes could be placed into 6 clusters. Genotypes grouped in Cluster III and I have highest mean value for all characters as well as highest inter-cluster distance.&nbsp;&nbsp;</div>

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