Grain morphological traits and genetic variability of upland rice genotypes

Grain shape is characterized by a combination of grain length, grain width, grain length-to- width ratio, and grain thickness diverge according to the rice cultivar. The aim of this work was to evaluate in grains of upland rice genotypes the morphological traits and identifying the genetic divergence between them, using hierarchical and non-hierarchical clustering techniques. The experiment was carried out in randomized blocks, with 42 upland rice genotypes. The following parameters were determined with digital caliper in a sample of 20 paddy rice grains per plot: grain width (greater side dimension), grain trickness (smallest side dimension), grain length (distance between tips) and GLGW= length-to-width ratio. The data were first submitted to the F-test (p<0.05) and to the Scott-Knott multiple comparison test at p<0.01 and p<0.05. Correlogram of Pearson's linear relationship was carried out and Cluster analysis was performed in two stages, using a hierarchical and non- hierarchical method in R Core Team software version 4.0.2. It is concluded that there is high genetic divergence among the upland rice genotypes. The genotypes OSVR15029 and OSVR15044 have similar traits to the cultivar IAC 202. The genotypes which have grains classified as long-thin, meeting national preferences and can be used for the breeding programs of upland rice crop.