RECOMBINING DORMANCY AND WHITE SEED COLOR IN A SPRING WHEAT CROSS

Abstract

Wheat, Triticum aestivum, with white seed coat color has traditionally been considered susceptible to sprouting. A study was undertaken to recombine white seed color with resistance to sprouting. RL 4137, a spring wheat (Triticum aestivum L.) genotype with a long, stable dormancy period and three genes for red seed color, was hybridized with 7722, a white-seeded wheat. In both the F3 and F5 generations a positive relationship existed between red seed color and sprouting resistance (SR). The six white-seeded F3 lines exhibited a range in SR from susceptible to as resistant as some red-seeded control cultivars. The mean SR of two white-seeded F4 families was intermediate to both the red-seeded and white-seeded controls at both T0 (20% grain moisture) and T10 (T0 + 10 days). Some white-seeded F4 lines had lower sprouting at T10 than the red-seeded controls Pitic 62, Neepawa, and Glenlea. The dormancy of six white-seeded F5 families derived from F3 lines was greater than the midparent value. There were significant differences among the white-seeded F5 families for mean dormancy. The results indicate that some of the dormancy of RL 4137 has been recombined with white seed coat color. The evidence suggests that RL 4137 has a genetic mechanism for SR associated with red seed color and one or more mechanisms not associated with seed color.Key words: Triticum aestivum, dormancy, white seed color