STUDIES ON GENETIC DIVERGENCE IN COWPEA (VIGNA UNGUICULATA) BY USING D2 SATISTICS UNDER SEMI-ARID CONDITIONS
NGOC VU NGUYEN, R. K. ARYA, RAVISH PANCHTA, AND JAYANTI TOKAS
Southern Horticultural Research Institute,
Tien Giang, Viet Nam
*(e-mail : email@example.com)
(Received : 14 December 2017; Accepted : 28 December 2017)
The field experiment was carried out by using the 30 genotypes of cowpea during Kharif season, 2017 at Directorate of Farms, CCS Haryana Agricultural University, Hisar, Haryana, India. Based on D2 analysis, these genotypes were grouped into six clusters. Cluster pattern revealed that cluster I and II were the largest groups, each has the eight genotypes, followed by cluster III (6 genotypes), cluster V (4 genotypes), cluster IV (3 genotypes) and cluster VI (1 genotype). The maximum intra-cluster D2 value was shown by cluster V (19.85) followed by cluster III (19.35), cluster IV (18.49) and cluster I (15.63). The intra-cluster D2 values ranged from 15.63 (cluster I) to 19.85 (cluster V). Highest inter-cluster D2 values among genotypes existed between clusters III and VI (52.08), followed by clusters III and V (45.99), clusters IV and V (43.62) and clusters II and III (41.21). There were high variations of mean values among six clusters for all characters which, cluster V revealed the highest mean value for almost desirable seed yield characters i.e. seed yield per plant, number of clusters per plant, number of pods per plant, harvest index, seed protein content and early in maturity). Cluster III had exhibited superior characters of biological yield and plant height. On the contrary, cluster VI had smallest mean values for almost important characters. It can be concluded that, the crossing between the genotypes of most divergent clusters i.e. cluster III (KBC-8, GC 901, VCP 09-019, KBC-6, PTB-1, UCP 12-007) and cluster VI (TC 150) could able to produce highest seed yielding transgressive segregants. Moreover, high seed yield would be achieved by hybridization between genotypes of clusters V and II which having greater mean values for seed yield and its component traits.
Key words: Genetic divergence, cowpea, Vigna unguiculata, D2 satistics, transgressive segregants