Genetic divergence in sunflower (Helianthus annuus) inbreds

Abstract

Increase in seed yield is the main objective of sunflower breeding programs. Genetic variability is the basic prerequisite for each breeding program. Determination and knowledge of genetic variability facilitate the selection of superior genotypes in different generations of selfing. In breeding programs, much effort is expended each year to find superior lines among a large number of tested lines. Genetic divergence has been analyzed in 125 sunflower inbred lines for the following traits: 1) number of florets per plant, 2) number of seeds per plant, 3) percentage of pollination per plant, 4) autofertility and 5) autocompatibility. The selected lines differed in the values of the analyzed traits. Relationships between and within groups of lines were analyzed by a discriminant analysis, which uses mean values of individual plants, and groups of plants and lines. Mahalanobis squared distance served as a measure of similarity. Based on the analyzed traits, it was concluded that 23 inbred lines do not belong to the groups they were allocated in on the basis of the pedigree method of selection. The accuracy of classification varied from 68 to 88%.