Hulless barley (Hordeum vulgare L.) resistance to pre-harvest sprouting: diversity and development of method for testing of breeding material
State Priekuli Plant Breeding Institute, Zinātnes str. 1a, Priekuli LV-4126, Latvia;e-mail: firstname.lastname@example.org
Pre-harvest sprouting significantly reduces grain yield and quality of hulless barley (HB). In field conditions pre-harvest sprouting resistance can be scored rarely. The objective of the research was to develop appropriate testing method for barley breeding material in laboratory conditions and to estimate genetic diversity in pre-harvest sprouting resistance among various HB genotypes. The amount of seeds with visible germination symptoms were determined in days 4, 7 and 10 after initiation of laboratory test; it was started in ripening stage and after 4 weeks of storage of harvested spikes. The average amount of germinated grains differed significantly between the three estimation days (p < 0.001) in all years and both if tested in ripening stage or during storage. The effect of genotype on the number of germinated grains was the highest in the 10th testing day. Germination was significantly higher if the test was started after 4-week storage of harvested spikes. The correlation between amounts of germinated grains with the sprouting scores obtained in field conditions was significant in most of the cases; the highest values of correlation coefficient were obtained in estimation days 7 and 10 if the test was started in ripening stage. As more suitable for performing laboratory test of pre-harvest sprouting in barley breeding program can be suggested testing in ripening stage with estimation day 10 or 7. A noticeable variation of amount of germinated grains among the genotypes was found (CV = 49.8%, 10th estimation day). It approves the possibility for improvement of this trait by breeding.