BSSS53 as a Donor Source for Increased Whole‐Kernel Methionine in Maize

Increasing the whole‐kernel methionine [MET; 2‐amino‐4‐(methylthio)‐butyric acid] level of maize (Zea mays L.) would improve the quality of the grain for poultry feed. Our objective was to increase the MET levels of A632, B73, Mo17, A632/Mo17, B73/A632, and B73/Mo17, with the high‐MET inbred BSSS53 as a donor parent. Backcross‐derived lines were evaluated per se in trials during 3 yr, and hybrids among subsets of these lines were evaluated in three replicates during 1998. Methionine levels of the best A632 recoveries were increased by 17% after three backcrosses and 11% after four backcrosses. Methionine levels of the best B73 recoveries were increased by 20% after three backcrosses and 17% after four backcrosses. In the Mo17 genetic background, MET levels of the best recoveries were increased by 55% after three backcrosses and 31% after four backcrosses. Crosses among the highest MET backcross‐derived lines produced hybrids with significant 23 to 43% increases in whole‐kernel MET compared with corresponding control hybrids. Significant increases in the MET levels of experimental hybrids indicate that BSSS53 is a useful donor source of whole‐kernel MET and that selection within normal dent maize germplasm can be effectively utilized to produce high‐MET hybrids.