Combining abilities and heritability of callus formation and plantlet regeneration in wheat (Triticum aestivum L.) anther cultures.

Frequency of callus formation in wheat (Triticum aestivum L. em. Thell) anthers cultured in vitro and the frequency of subsequent plantlet formation from such calli were examined in a diallel population produced from five inbred spring wheat cultivars. Two of the five cultivars were believed to possess relatively high frequencies of response and the other three relatively low response frequencies, based on previous studies. General and specific combining abilities were estimated and found to be highly significant for both traits. Reciprocal effects were also estimated and were highly significant for both traits. Of the 25 entries, the largest mean callus formation frequency was observed on anthers of 'Kitt' x 'Olaf', while the largest mean plantlet formation frequency was observed using anthers of the cultivar, 'Fielder'. No significant correlation was observed between the two traits. Heritability estimates in the range of 0.6-0.7 suggested, however, that both traits were highly heritable, so that rapid gain from selection for these traits should be possible. Current limitations due to genetic variation in responses therefore may not constitute a major obstacle to application of in vitro techniques by wheat breeders.