Assessment of Morphological and Molecular Genetic Diversity in Pigeonpea [Cajanus cajan (L.) Millspaugh]

Abstract

Background: The estimation of genetic diversity in pigeonpea is crucial for desiging breeding programmes and germplasm conservation. Morphological studies alone do not provide sufficient information to understand genetic diversity. Molecular analysis using SSRs can provide additional information on genetic diversity that can be used for selection of diverse parents. Methods: The experimental material for present study consisted of 50 diverse genotypes of pigeonpea. The fifty genotypes were planted in Randomized Complete Block Design consisted of three replications during the kharif 2020-21. The estimation of morphological genetic diversity was done by Mahalanobis D2 statistics. The molecular genetic diversity analysis was done by using 30 molecular markers in same genotypes. Result: The assessment of morphological diversity revealed that the fifty pigeonpea genotypes were grouped into four different clusters with cluster I as the largest cluster (33 genotypes). The molecular markers differentiated the 50 genotypes in five major clusters with cluster II as the largest cluster (24 genotypes). The results of present study suggested that morphological and molecular diversity in pigeonpea is different. On the basis of genetic distance, the genotypes RVSA 2014-1 and PA 406 were found most genetically distant and may be used in hybridization programme to create diverse progenies.

Assessment of Genetic Diversity using D2 Statistics among the Medium Maturity Pigeonpea [Cajanus cajan (L.) Millspaugh] Genotypes

“…The minimum diversity was contributed by pods/plant (2.38%) followed by primary branches/plant (4.76%), days to 50% flowering (6.19%) and plant height (8.10%). This is in conformity with Naing et al [12] when they reported that more contribution towards genetic diversity for pigeon pea are days to maturity, pods/plant, days to 50% flowering and seed yield; Ranjani et al [8] observed that maximum contribution towards the genetic diversity for the traits i.e., 100-seed weight and days to maturity; Sandeep et al [14] reported maximum contribution for seed yield, 100-seed weight and days to 50% flowering [15].…”

“…These results indicated that if hybridization is attempted between the genotypes included in these cluster, lot of genetic diversity will be produced in the segregating generation and the selection for desirable genotypes can be practiced. The greater intercluster distance as comparison to intra-cluster distance was also reported by previous workers Bisht et al [11], Naing et al [12] and Pushpavalli et al [13]. The maximum inter-cluster distance (16.54) between the cluster II and cluster VI followed by cluster IV and VI with the distance (14.34) and Cluster III and VI (13.22) indicating that genotypes from these clusters were highly divergent and hence selection of parents for hybridization from these clusters is suggested for realization of maximum heterosis.…”

Assessment of genetic diversity in blackgram [Vigna mungo (L.) Hepper] germplasm

“…Even though India is the largest producer of black gram, its average productivity and per cent contribution towards the total pulse production is less due to the lack of genetic variability, unavailability of potential ideotype, poor harvest index and lack of resistances to biotic and abiotic stresses (Devi et al, 2020). These constraints are due to ingeminate usage of related parents in hybridization programmes (Jayamani and Sathya, 2013) and breeding for few economic traits to reach the targets of market requirements (Naing et al, 2022). Hence, to develop the cultivars with wide genetic base, there is a need to estimate the genetic divergence among the available black gram germplam.…”