Quantitative inheritance in sunflower (Helianthus annuus L.)

Abstract

This study was conducted in order to estimate the gene effects which determine the inheritance of certain characters and to search the genetic structure of each group in a 9 x 9 diallel cross group established by crossing inbred lines of sunflower. (1) Significant positive heterotic effects were observed for all the characters studied but for different number of crosses. According to the results obtained, two to three parents were observed to be good general combiners for seed yield and eight hybrids were promising crosses for seed yield and plant height. (2) Both additive and dominance genetic variances were significant for all characters. Also, the overall mean dominance effect of heterozygous loci, h2was significant for all characters. It was found that positive and negative alleles at these loci were not in equal proportions in the parents (i.e., H1>H2). The average degree of dominance showed overdominance for all characters. © 2002, by Walter de Gruyter Berlin/Boston. All rights reserved.