Selection of interspecific hybrids for anther culture of indica rice

The low percentage of callus induction and green-plant regeneration has limited the application of anther culture techniques in indica rice breeding programmes. The aim of this work was to investigate the inheritance of the two characters and to determine whether good combinations with high-frequency callus induction and green-plant regeneration could be selected by sexual hybridization of suitable parents. So, a 3 x 4 incomplete diallel crosses were conducted between 7 parental lines. Three of them were believed to possess relatively high callus induction capacity and the other four relatively high green-plant regeneration capacity, based on our previous studies. Analysis of combining abilities and heritabilities revealed that both additive and non-additive effects were found to be important in the genetic control of callus induction. In case of green-plant regeneration, non-additive effects were predominant. Broad sense heritability values of 0.92 for callus induction and 0.98 for green-plant regeneration suggested that more than 90% of the observed variation was due to genetic effects, with just less than 10% attributed to non-genetic or environmental effects. In addition, the moderate narrow sense heritability values of 0.49 for callus induction, 0.29 for green-plant regeneration showed that the potential to introduce high responding ability into low lines was moderate. It was therefore conceivable that the frequency of anther culture response might be improved by suitable hybridization and selection strategies. A hybrid combination of code no. 67/107 incorporating high callus induction and high green-plant regeneration ability was selected in which genotype with high values of general combining ability (GCA) and positive effects of specific combining ability (SCA).