Jingjuan Zhang

By using bioinformatics, the barley semi-dwarfing gene, sdw1, was found to be similar in its structure to that of the semi-dwarfing gene, sd1, in rice. Part of exon1, whole of exon2 and intron 1, and part of exon3 of this gene sequence was isolated from barley and the sequences of twelve barley varieties were compared in intron1 and exon2 regions. The similarity and differences of DNA and protein sequences between sdw1 (barley) and sd1 (rice) were compared. The most likely GA20-oxidases in wheat, barley and rice were analysed and discussed. The sequences of intron1 and exon2 obtained from these experiments indicates that the respective regions are most unlikely to be the source of the differences in sdw1 status between the varieties tested. Further experiments will be used to develop a diagnostic marker to distinguish different sdw1 alleles in order to modify pleiotropic effects on other traits such as long coleoptile, strong initial vigour combined with suitable kernel shape and size.