II.5. Test for allelism between Hiproly and notch mutants.
H. C. Bansal and S. Bhaskaran. Nuclear Research Laboratory, Indian Agricultural Research Institute, Delhi 12, India.
Two mutants designated notch-l and notch-2 were observed to show high DBC values and high protein content (BGN, 2:21, 1972). The results of further analysis have shown that they also contain high lysine. The percentage of increase in lysine at constant weight of protein was to the extent of 20% in notch-2 and 25% in notch-l as compared to the mother strain. The increase in lysine was more than 30% when compared with the standard varieties of recent origin. These mutants are comparable to Hiproly with regard to lysine and other essential amino acids but superior to Hiproly barley in their yielding abilities. Studies have also shown that the trait for increased protein content and quality can be incorporated into plump grains de-linking the undesirable notched character.
The crosses were made between notch-l x Hiproly and notch-2 x notch-l to ascertain the allelic nature of genes governing quantity and quality of protein and the results have shown that the genes for quality and quantity are different in these three genotypes. Positive transgression was, however, not obtained in these crosses. Negatively skewed transgression could be due to epistatic genetic interaction.
The results of these crosses also showed that the effects of genes of Hiproly and notch mutants could not be combined in an additive fashion even in the very much shrivelled grains. This suggests that there may be a threshold value beyond which no further increase in the grain protein and quality seems to be feasible. Further evidence in this direction was obtained when these three genotypes were further mutagenized with EMS (0.3%) and screened for quality employing DBC technique. There was no significant increase in the DBC values in the treated population over control, however, the spread of DBC values was in the negative direction. This aspect is being further tested in diverse crosses.