Vol. 11, Issue 7 (2022)

Author(s):
RK Mandal, UK Singh and Rajesh Kumar

Abstract:
Genetic diversity is one of the most basic prerequisites in any crop improvement programme. It acts as a reservoir for identifying superior genes influencing quantitative traits of the crops and use of rice genetic resources. Genetic divergence study was carried out at research farm of Dr. Rajendra Prasad Central Agricultural University Pusa, Samastipur, with 24 diverse lowland rice genotypes. Which were shown in R.B.D. design and were analysed for genetic divergence with the help of Mahalanobis’s D² statistics. The 24 rice genotypes were grouped into eight clusters. Cluster II was found to be largest comprising of 13 genotypes followed by cluster III having 3 genotypes, cluster I and cluster VIII having 2 genotypes each and cluster IV, cluster V, Cluster VI and cluster VII having 1 genotype each. The highest intra cluster distance was observed in cluster VIII (5.75) followed by Cluster II (5.70). Maximum inter cluster distance (18.03) was observed between cluster I and Cluster VII followed by inter cluster distance (14.57) between cluster I and cluster VI. The pattern of distribution of genotypes from different geographical regions into various clusters was at random indicating that geographical diversity and genetic diversity were not related. Per cent contribution of all ten characters towards total genetic divergence was found maximum for plant height followed by days to flowering, grain filling rate. It was observed that plant height ranked 1st maximum times followed by days to flowering, grain filling rate, 1000 grain weight. The genotype in cluster I and cluster VII due to maximum inter cluster distance between them, exhibited high degree of genetic diversity and thus may be utilized in future for heterosis breeding programme for getting high yielding recombinants.