Genetic analysis of plant regeneration ability in anther culture of rice (Oryza sativa L.)

The inheritance of regeneration ability in anther culture of rice (Oryza sativa L.) was studied using direct regeneration method (subcultureless anther culture) to evaluate the regeneration ability without any influence of the subculture of calli. In anther culture of 176 F-1 combinations, a positive coefficient of correlation between a regeneration rate per anther and coefficient of relationship to Sachikaze with F-1 hybrid was observed. A negative correlation between regeneration rate and coefficient of relationship to Norin 1 with F-1 hybrid was also observed. In 4 x 4 diallel analysis using Sachikaze (Nipponbare's maternal variety), Norin 1 (Koshihikari's paternal variety), Nipponbare and Koshihikari, different genetic effects were observed on different medium. Especially, on the Ns medium containing 0.l mu M 2,4-dichlorophenoxyacetic acid (2,4-D), 5 mu M naphthalene acetic acid (NAA), 70g/l sucrose and 2mg/l glycine, the relationship between Vr and Wr showed that the low regeneration ability was dominant. Nipponbare possesses recessive alleles at almost all the loci. On the contrary, Norin 1 and Koshihikari have dominant alleles at almost all the loci. Additive effect, mean dominance effect and dominance effect due to specific parent were significant. No epistasis was detected. Reciprocal effect was not significant in plant regeneration. In callus formation, there was no significance in both additive and dominant effects on any media tested. It was suggested that different genes were involved in regeneration ability from callus formation ability. No significance in any genetic effects in regeneration was observed on the medium with alanine, although the regeneration rare became higher as a whole by adding the amino acid into the medium. These results suggest that genes or effects of genes for regeneration were varied for different media.