Genetic diversity analyses of rice germplasm using morphological traits

The study of genetic diversity of any germplasm helps to facilitate its use and management. This experiment was carried out to determine the genetic diversity among 87 rice accessions from six countries. Seventeen quantitative traits were recorded based on the internationally accepted standard evaluation system for rice from IRRI. Analysis of variance, principal component analysis (PCA) and correlation amongst quantitative traits were carried out. Highly significant (P<0.001) differences were observed among the accessions for all the quantitative traits. The first five principal components accounted for 75.01% of the total genetic variance among the accessions. Some of the morphological traits had significant positive correlations with grain yield. At 21% similarity coefficient, the 87 accessions from six countries were grouped into seven clusters based on the morpho-agronomic traits. Accessions from these seven clusters have tiller number of 10-20, erect culm angle, no awn, 90-120 days to 50% flowering, semi erect flag leaf, well exserted panicle and grain width of 2-3.5 mm respectively. This experiment has proven that morphological markers are effective in assessing genetic diversity in rice. The genetic diversity revealed by the morpho-agronomic traits in this study would be very important in selecting appropriate genotypes for rice improvement in Africa and elsewhere. Key words: Genetic diversity, morpho-agronomic traits, principal component analysis, rice.