Genetic Divergence and Heritability Study of Some NERICA Mutant Lines and Their Parents Using Microsatellites Marker and Morphological Traits in Rice

Abstract

New Rice of Africa (NERICA) is drought tolerant and early maturing inter specific rice variety which was introduced in Bangladesh from Uganda in 2009. But the field record of NERICA was not very promising. In order to develop NERICA varieties suitable for agro-climatic conditions of Bangladesh different variations in yield contributing characters are required.In the experiment, physical mutagen treated (250, 300 and 350 Gy Gamma-rays) 18 NERICA mutant lines were selected from M4 to M5 generations along with 3 parents (NERICA-1, NERICA-4, NERICA-10) for morphological and molecular evaluation in orderto identify desired mutant linesusing 12 yield attributing characters and 3 simple sequence repeat (SSR) markers. We also estimated heritability, genetic advance and correlation among the studied morphological traits to identify besttraits based on which further selection could be made. Pearson’s correlation co-efficient of 12 morphological traits indicated that yield per plant had significant positive correlation with the number of tiller, number of effective tiller, panicle length, number of filled grainsper panicle and 1000 grain weight but negative correlation with Plant height and days to maturity. Broad sense heritability ( ) ranged from 71% to 99% while genetic advances in percent mean (GA%) varied from 10% to 60%. Yield per plant, unfilled grains per panicle, number of total tiller, number of effective tiller showed high heritability along with genetic advance as percent of the mean (GA%) value. A total of 24 alleles were detected by 3 SSR markers. The mean gene diversity and Polymorphism Information Content (PIC) values was 0.821 and 0.797, respectively.  Dendrogram constructed based on SSR markers clustered the genotypes into six distinct clusters. Combining molecular and morphological evaluation data eight mutant lines, N10/300/P-2-3-5, N10/300/P-2-3-5, N10/300/P-2-3-5-2, N1/300/P-2-3-5, N1/300/P-2-3-5, N1/250/P-7-6-4-1, N10/300/P-2(1)-4-1 and N1/250/P-7-3-7-1were selected as desired mutant lines having good yield attributing characters and could be recommended for further evaluation in rice breeding program.