Genetic analysis of shoot regeneration from cotyledonary explants in Brassica napus

Genetic analysis of shoot regeneration from cotyledonary explants of Brassi ca napus was carried out by 7x7 diallel crosses using cultivars showing a d ifferent ability for regeneration. Both additive and dominant effects were significant, with the additive effect being more important than the dominan t one. Dominant genes had a positive effect on shoot regeneration. Non-alle lic interaction and average maternal effects were not detected, while speci fic the maternal one was significant. In the 5x5 sub-diallel table, the mat ernal effect became nonsignificant. The mean degree of dominance was 0.759, Broad- and narrow-sense heritabilities were 0.973 and 0.819, respectively, indicating that shoot regeneration ability can be easily transferred into economically important cultivars showing a low or an unresponsive ability.