Genetic Diversity Analysis for Yield and Morpho-physiological Traits in Elite Rice (Oryza sativa L.) Genotypes under Semi-dry System Through D2 Statistics

Abstract

Genetic divergence is a useful tool for choosing the parents to employ in a hybridization program. The current study was conducted at Agricultural College, Aswaraopet, Telangana, to evaluate genetic diversity among 30 rice genotypes during Kharif 2021 using D2 analysis under a semi-dry system. Based on the analysis, thirty genotypes were divided into ten clusters based on D2 values. Cluster II was found largest with twelve genotypes followed by cluster I with ten genotypes and clusters III, IV, V, VI, VII, VIII, IX, and X had one genotype each, indicating that there was a sizable amount of variation among the genotypes. Cluster II (284.13) had the highest intra-cluster D2 value, followed by cluster I. (242.63) while the highest inter-cluster distance was found between Cluster VIII and IV (1503.42) followed by cluster VI and IV (1316.83), cluster VI and III (1316.15), cluster IX and IV (1303.55), cluster VIII and X (1261.09), cluster VIII and IX (1132.95), V and III (1113.91), and cluster VII and V (1101.7) suggesting that crosses involving lines from these clusters would produce wider and more desirable recombination. The average inter-cluster distance for Cluster VIII and VI was the lowest (231.01), followed by Cluster IX and X (394.3) and Cluster III and IV (397.72). The genotypes of these clusters have the most gene complexes, as shown by the shortest inter-cluster distance. The findings revealed that root biomass contributed the most to genetic divergence (24.59 percent), ranking first followed by total biomass (21.60%), root length (17.70%) and grain yield/plant (14.02%), culm strength (8.04%), plant height (5.74%), 1000 grain weight (4.36 %). The traits viz., root biomass, total biomass, root length, grain yield/plant, and culm strength contributed 85.95% of the total deviation and need to be exploited to develop varieties suitable for the semi-dry system in rice. The genotypes BPT 5204, WGL 697, RNR 21278, RNR 28361, WGL 915, PR 126, and JGL 28545 were to be better for further hybridization programs to develop varieties for the semi-dry system.