STUDY ON GENETIC VARIABILITY AND DIVERSITY IN MAIZE (Zea mays)

Abstract

The field experiment was conducted in the experimental field of Department of Genetics and Plant Breeding, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh, during the period from October 2009 to March 2010 to study the genetic variability and diversity in hybrid maize. In this research work, the seeds of 10 maize genotypes were used viz. G,: Durga, G:: CML-492, G;: CML-503, Gy: Kanak, Gs: BHM-5, Ge: BHM-3, G7: NK-40, Gg: Bijoy, Go: Seed tee740 and Gio: NT-6323. The experiment was laid out in the Randomized Complete Block Design (RCBD) with three replications. Mean performance, variability, correlation coefficient, path analysis and divergence analysis were done on yield and yield contributing characters namely, days to male flowering, days to female flowering, days to maturity, plant height, tassel length, cob length, cob diameter, distance between tassel and cob, number of grains per cob, weight of 1000 grains and grain yield per plant. The highest grain yield per plant (211.18 g) was recorded from Gg (Seed tee-740) again, the lowest (135.26 g) was found from G3; (CML-503). Grain yield per plant in terms of phenotypic variation (835.21) was higher than the genotypic variance (575.71) which was supported by narrow difference between phenotypic (16.09%) and genotypic (13.36%) co-efficient of variation. Very high heritability (68.93%) for grain yield per plant attached with high genetic advance (52.59%) and low genetic advance in percentage of mean (29.28). Grain yield per plant of maize genotypes showed positive significant association with days to male flowering (0.589), days to female flowering (0.574), plant height (0.508), tassel length (0.673), cob length (0.703), cob diameter (0.510), distance between tassel and cob (0.400), number of grains per cob (0.506) and weight of 1000 grains (0.558) grain yield per plant in maize genotypes whereas insignificant positive association was recorded with days to maturity (0.289). All the genotypes were grouped in 4 clusters. Cluster II was the largest cluster comprising of 4 maize genotypes followed by cluster IV with 3 genotypes and cluster III comprises only 1 maize genotype. Cluster distances denoted by the average inter and intra-cluster distances are the approximate measure of the cluster divergence. Cluster IV had the highest intra-cluster distance (0.806) followed by cluster IIT (0.706). Cluster I had the lowest intra cluster distance (0.339) followed by cluster II (0.421). Inter cluster distance was maximum (7.665) between clusters III and IV, followed by clusters II and IV (6.195).