VARIABILITY AND DIVERSITY STUDIES IN MAIZE (Zea mays L.) INBRED LINES

Abstract

Twenty nine inbred lines of maize were evaluated for ten parameters at the experimental field of Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh during November 2014-April 2015 to study the genetic variability and diversity in maize inbred lines. The experiment was laid out in randomized complete block design (RCBD) with three replications. Mean performance, variability, coefficient of variation and diversity analysis of yield and yield contributing characters namely plant height, cob height, cob length, cob diameter, number of cobs per plant, tassel length, number of kernel rows per cob, number of kernels per row, total number of kernels per cob, 1000 grains weight were performed. The highest weight of 1000 grains (376.333g) was obtained from ML8, the lowest weight of 1000 grains (307.8g) was recorded from ML19, 1000 grains weight of phenotypic variation (335.029) was higher than the genotypic variation (59.52) which indicates high environmental effect was supported by narrow difference between phenotypic (99.58) and genotypic (41.97) co-efficient of difference. Weight of 1000 grains had inherent potential among the genotype high heritability (17.766) for this trait along with high genetic advance in percentage of mean (36.29). All the genotypes were grouped into five clusters. Cluster I was the largest cluster comprising of nine maize genotypes followed by cluster II(6) and III (6). Cluster distance denotes by the average inter and intra cluster distance are the approximate measure of the cluster divergence. The maximum inter-cluster divergence was observed between the clusters I (32.84) and II (15.68) and it was minimum between clusters III (11.75) and IV (4.66). The maximum value of inter – cluster distances indicated that the genotypes belonging to the cluster II is far diverged from those cluster V. Both vectors (vector I and Vector II) were positive for plant height, cob height, cob length, cob diameter. So these four characters had the highest contribution towards the divergence among 29 maize inbred lines. Intra cluster distance was much lower than the inter cluster one, suggesting, heterogeneous and homogeneous nature between and within groups.