Agronomic trait diversity in rice genotypes as a resource for crop improvement and food system resilience

Food security is a critical foundation for human development, particularly in Sub-Saharan Africa where rapid population growth demands increased food production. In rice breeding programs, early-stage diversity assessment is essential for guiding selection and advancement of genetic resources, yet it is often underutilized during observational yield trials (OYT). This study evaluated phenotypic diversity among early-generation rice genotypes to support breeding decisions. A total of 198 test lines and three check varieties were assessed under field conditions using an augmented design at Tanzania Agricultural Research Institute Dakawa Centre. Significant genotypic differences were observed for days to 50% flowering (X50) and empty grains per panicle (EGP) at the 1% level, and for panicle length (PL) and grain yield per row (GYR) at the 5% level. Cluster analysis grouped genotypes into four clusters, with Cluster 4 showing superior performance across key traits. Greater inter-cluster than intra-cluster distances indicated substantial diversity. These findings highlight the importance of phenotypic diversity analysis at OYT, though integration of molecular tools such as SNP markers is recommended to improve selection efficiency.