Abstract

This work aimed to evaluate the genetic divergence among 16 sunflower hybrids. Experiment was developed in Umuarama County, Parana State, Brazil, in 2010/2011 cropping season. Experimental design used was randomized complete block with four replications. The characteristics evaluated were: Final stand, plant height, chapter curvature, chapter size, grain yield, weight of 1000 achene’s and oil content. Significant differences were detected for grain yield, chapter size and chapter curvature (1%). For final stand and oil content, significant differences (5%) was observed, suggesting that evaluated characters are important for genetic divergence characterization. Based on Mahalanobis Generalized Distance it was established that genetic dissimilarity measures, SULFOSOL and SYN 045 genotypes were the most dissimilar with D²_ii’ of 134.54%. Clustering by Tocher method by using D²_ii, divided hybrids into two groups. Grain yield and chapter size contributed significantly in genetic divergence observed between hybrids and it was possible to identify divergent genetic materials for obtaining lines and/or formation of new populations.

Key words: Genetic variability, plant breeding, Helianthus annuus L., D²ii' analysis.