GENETIC-DIVERGENCE AMONG THE PARENTS OF THE IRRIGATED RICE POPULATIONCNA-IRAT-4

Multivariate techniques were utilized to evaluate the genetic divergen ce among ten parents of the irrigated rice population CNA-IRAT 4. Ten selected characteristics were evaluated in a field experiment conducte d in Goianira, GO, adopting a randomized block design with four replic ations. Canonical variate analysis and cluster analysis using Tocher's aglomerative method and hierarchical method (nearest neighbour) were applied. The dissimilarity measure used was generalized Mahalanobis di stance (D-2). There is significant genetic divergence among parents, i ndicating variability in various useful characteristics of the populat ion. The Tocher's method detects a higher number of groups compared to the nearest neighbour or canonical variate methods. The highest diver gence is observed between Nanicao and CNA4840, whereas CNA3848 and CNA 3887 show the highest similarity. Plant height, days to flowering and grain weight explain the majority of the genetic divergence among pare nts. By other hand, grain size and number of spikelets contribute leas t to divergence.