Agronomic performance, genetic variation and heritability of yield and related traits in rice genotypes under upland conditions

Abstract

Although rice production potential under rain fed ecology doubles that of irrigated lowland in Kenya, there has been little advancement in identifying suitable varieties adapted to upland rice ecology. This study was carried out to appraise the agronomic performance, heritability, grain yield components, genetic variability, and correlations for grain yield and identity of suitable varieties for the upland ecology. Eight rice genotypes were evaluated in a randomized complete block design alongside three replicates under upland conditions. Collection of data included days to 50% flowering, height of the plant, productive tillers-1, panicle length, grain length, panicle weight, grains panicle-1, spikelet fertility, grain yield weight of one thousand grains, grain breadth and breadth/ length ratio of the grain. Data analysis involved Analysis of variance, broad sense heritability estimates determination and principal component analysis. Genotype’s variation was significant for all traits measured. The first three principal components accounted for 94.67% of the sum variation among 12 traits under study. The outcome of heritability estimates and the PCA indicated that the characters 50% flowering days, weight of a thousand grains, spikelet fertility, length of the panicle, grain breadth, length of the grain and breadth/length ratio, accounted for most of variance in the variables observed and showed average to high broad sense heritability. Therefore, for these traits, early generation selection was effective in identifying superior genotypes following hybridization. From the eight cultivars used in the study, NERICA 10 and NERICA 2 varieties had better indicators for coastal lowlands of Kenya.