Pre-Harvest Sprouting and Dormancy in Diverse Wheat Genotypes

SUMMARY Fifty wheat genotypes have been sown in northwestern Croatia, in 1994/95 and 1995/96 in order to determine variation for pre-harvest sprouting susceptibility and dormancy. Sprouting susceptibility was tested at physiological maturity, using intact spikes in wet paper towels. Dormancy level was detected from simple germination tests on treshed seeds at three intervals after harvest . 24 genotypes in 1995 and 30 genotypes in 1996 had the same level of sprouting resistance at physiological maturity as the sprouting resistant standard RL.4137. By comparison, a smaller number of genotypes were ranked equal to RL.4137 on the basis of the level of dormancy measured at three intervals after harvest. More genotypes appeared similar to RL.4137 on the third than after the seventh day of germination. This was a consequence of the low level of germination at the third day combined with relatively high level at the seventh day in some genotypes. In addition to a lower germination percentage , dormancy in these genotypes was detected as delayed germination. Thus, dormancy measurements after both three and seven days of germination would appear to be useful for detection of this characteristic. High genotype by environment interaction observed for sprouting susceptibility as well as for dormancy suggests the need of testing genotypes in more environments.