Genetic variability in oilseed rape DH line population developed from F 1 hybrids obtained by crossing black-and yellow-seeded DH lines. I. yield and yield components

The aims of this study were to estimate the diversity of doubled haploid population of winter oilseed rape ( Brassica napus L.) in terms of yield, yield structure and seed colour, to determine the correlation between the studied traits and their heritability, and to select the best yellow-seeded genotypes. We studied 44 doubled haploids, obtained from F 1 hybrids of a cross between a black-seeded DH H 2 -26 line and a yellow-seeded DH Z-114 line, as well as the parental forms. The greatest variation in DH line populations was observed for seed colour, seed yield and the number of pods per plant, while the smallest variability was obtained for thousand seed weight. Seed yield was positively correlated with the number of pods per plant and the number of seeds per pod, but negatively correlated with yellow seed colour. The broad-sense heritability coefficient was highest for seed colour and number of seeds per pod, and lowest for the number of pods per plant. When divided into 4 homogeneous groups according to seed colour, the genotypes differed significantly with respect to all the studied traits. A group of DH lines with black seed colour was characterized by the highest seed yield as well as highest thousand seed weight. The lowest yielding DH line group, that with yellow–brown seeds, had on average the highest number of seeds per pod and the lowest thousand seed weight. The best yellow-seeded genotypes were selected. Four yellow-seeded lines gave significantly higher yields than the yellow-seeded parental line.