Genetic Variability and Diversity Pattern for Agromorphological Traits in Indian Mustard Germplasm

Abstract

Genetic diversity studies were carried out on 302 indigenous accessions of Indian mustard [Brassica juncea (L.) Czern & Coss] for variability assessment and identification of trait-specific germplasm. The Indian mustard germplasm was evaluated for eight important morpho-agronomic traits. Geographic information system (GIS), principal component and cluster analysis were carried out to analyse major clusters. Four principal components were identified explaining more than 74% of total variation. Three promising germplasm accessions (IC342781, IC570320 and IC426354) identified with maximum number of seeds per siliqua (>18.0 seeds) were collected from districts Patna (Bihar) and Adilabad (Andhra Pradesh). Similarly, three promising accessions (IC426398, IC521376 and IC395557) were identified with high oil content (>40%) from districts Nizamabad (Andhra Pradesh), Godda (Jharkhand) and Gorakhpur (Uttar Pradesh) respectively. The cluster analysis grouped mainly in two major clusters I and II and further sub-divided into a and b sub-groups. In cluster I sub-group b which indicates a close relationship between traits-the days to mean flowering and days to mean maturity while the plant height was grouped individually. In cluster II, number of primary branches and number of seeds/siliqua showed close relationship with oil content as compared to other traits. GIS based grid maps using Shannon-Weaver diversity index (0–4.0) were generated for showing high variability areas (light red/dark red grids) in different agro-ecological regions of India. The results indicated that Indian mustard germplasm collected by NBPGR from different parts of India has broad genetic base. Thus, promising genotypes identified for various economically important morpho-agronomic traits can be utilized to develop improved varieties of Indian mustard.