Faiz Ahmad

Rice varieties that exhibit the early-flowering (EF) trait are of growing relevance to modern agricultural practices, enabling multiple cropping cycles per year (Waha et al. 2020; Aisya et al. 2024...

Genetic diversity has been pivotal in unleashing the roles of genes and traits in crop productivity and resistance ability against multiple stresses. In this study, the main objective was to investigate the genetic variation of six local aromatic rice varieties in Malaysia for twelve agronomic characters by using multivariate analysis, viz., genetic parameters, correlation analysis, path coefficient analysis and cluster analysis. The results illustrated that the phenotypic coefficient of variance (PCV) was higher than the genotypic coefficient of variance (GCV) for all characters, despite small differences in values among them. All the characters also revealed a high heritability index (h2 b) except for the length of the panicle. Five characters, namely plant height, number of tillers, number of panicles, weight of 1000 grains and number of unfilled grains per panicle, possessed both a high heritability index and genetic advance as percentage of mean (GA%). These five characters could be used as primary selection criteria for future rice hybridisation or improvisation of the sole aromatic variety. As for the correlation analysis, the number of filled grains per panicle and the length of the seed illustrated a strong correlation and a positive direct effect on the yield rate per plant. According to UPGMA cluster analysis, the varieties were clustered into three groups. Rice variety in Cluster III (MRQ 76 and MRQ 104) and II (MRQ74, MRQ88 and MRQ103) could be considered for further hybridisation to attain a wide spectrum of variation as well as the greatest performance in agronomic performance.

Coloured rice genotypes have greater nutritious value and consumer demand for these varieties is now greater than ever. The documentation of these genotypes is important for the improvement of the rice plant. In this study, 42 coloured rice genotypes were selected for determination of their genetic divergence using 25 simple sequence repeat (SSR) primers and 15 agro-morphological traits. Twenty-one out of the 25 SSR primers showed distinct, reproducible polymorphism. A dendrogram constructed using the SSR primers clustered the 42 coloured rice genotypes into 7 groups. Further, principle component analysis showed 75.28% of total variations were explained by the first—three components. All agro-morphological traits showed significant difference at the (p≤0.05) and (p≤0.01) levels. From the dendrogram constructed using the agro-morphological traits, all the genotypes were clustered into four distinct groups. Pearson’s correlation coefficient showed that among the 15 agro-morphological traits, the yield contributing factor had positive correlation with the number of tillers, number of panicles, and panicle length. The heritability of the 15 traits ranged from 17.68 to 99.69%. Yield per plant and harvest index showed the highest value for both heritability and genetic advance. The information on the molecular and agro-morphological traits can be used in rice breeding programmes to improve nutritional value and produce higher yields.