ASSESSMENT OF GENETIC DIVERSITY IN BORO RICE GENOTYPES

Abstract

An experiment was carried out at Sher-e-Bangla Agricultural University in Boro season with thirty two local varieties of Boro rice to identify the diversity among the genotypes. The varieties were examined for eighteen yield and yield contributing characters. Significant variation was observed among all the genotypes for all the characters under studied. High heritability along with high genetic advance in percentage of mean were observed for culm diameter and yield/plant. High heritability along with moderate genetic advance in percentage of mean were observed for 50% heading, plant height and1000 seed weight. High heritability along with low genetic advance in percentage of mean were observed for 1 st heading and days to maturity. Highly significant positive correlation of yield per plant observed for 1 st heading (r g =0.538, r =0.422,), 50% heading (r g =o.529, r p =0.440), days to maturity (r g =0.603, r =0.413), culm diameter (r g =0.258, r p =0.216), length of flag leaf (r g =0.214, r =0.226), no. of filled grain of main tiller (r g =0.617, r p =0.502) and 1000 seed weight (r p g p =0.386, r =0.286) at both genotypic and phenotypic level. Path analysis indicated that, yield per plant had positive and direct effect through 50% heading, culm length, culm diameter, length of flag leaf, no. of effective tiller/plant and no. of filled grain of main tiller and 1000 seed weight. On the basis of D 2 -value the genotypes were grouped into six clusters. Cluster V was the largest and containing twelve genotypes followed by cluster II with seven genotypes and cluster III with only five genotypes. The highest inter cluster distance was observed between cluster III and cluster IV (13.985). The intra cluster distance was maximum (0.367) in cluster IV. The lowest inter-cluster distance was recorded between cluster II and VI (1.486). Cluster I showed maximum performance for no. of effective tiller/plant (13.64). Cluster II showed maximum performance for 1 st heading (114), 50% heading (120) and culm diameter (0.60 cm). Cluster III recorded highest mean performance for days to maturity (161.33), length of flag leaf (27.980 cm), no. of filled grain of main tiller (198.67), 1000 seed weight (30.33 g) and yield/plant (33.01 g). Cluster IV showed maximum performance for plant height (123.28 cm) and culm length (72.510 cm). Cluster V did not show maximum performance for any character. Cluster VI showed maximum performance for length of panicle (25.65 cm). Considering the degree of variability, heritability, genetic advance in percent of mean, correlation with grain yield, path analysis, magnitude of distance, contribution of different characters towards the total divergence, magnitude of cluster means for different characters and performance, the genotypes G15, G26, and G27 for yield per plant from cluster III; G20 for earliness from cluster IV might be considered better parents for efficient hybridization program. p p