Genetic divergency among the parents of the irrigated rice population CNA-IRAT 4

Abstract

Multivariate techniques were utilized to evaluate the genetic divergence among ten parents of the irrigated rice population CNA-IRAT 4. Ten selected characteristics were evaluated in a field experiment conducted in Goianira, GO, adopting a randomized block design with four replications. 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 distance (D²). There is significant genetic divergence among parents, indicating variability in various useful characteristics of the population. The Tocher's method detects a higher number of groups compared to the nearest neighbour or canonical variate methods. The highest divergence is observed between Nanicão and CNA4840, whereas CNA3848 and CNA3887 show the highest similarity. Plant height, days to flowering and grain weight explain the majority of the genetic divergence among parents. By other hand, grain size and number of spikelets contribute least to divergence.