Effect of Temperature on Seed Dormancy of Wheat1

Publisher Website
Google Scholar
Abstract
In wheat (Triticum aestivum I.) the level of seed dormancy expressed depends on the temperatures encountered during the grain‐filling period. Because of the significant role of seed dormancy in preharvest sprout damage of wheat cultivars, this study was undertaken to determine the levels of seed dormancy induced in wheat cultivars ‘Hyslop’, ‘Yamhill’, ‘P.I. 178211’, ‘Brevor’, and ‘Tom Thumb’ grown at controlled temperatures at 15 and 26°C in growth chambers during the grain‐filling period and in the field‐grown plants. The degree of dormancy was measured in terms of weighted germination percentage (WGP) that takes into account the rate and number of seeds that germinated at controlled germination temperatures of 15, 20, and 26°C. Yamhill and Hyslop exhibited the least potential for producing dormant seeds. Seeds of P.I. 17(1211, Brevor, and Tom Thumb acquire some dormancy when developed at 26°C, but the greatest degree of dormancy was measured in seeds developed at 15°C. It appears that the maximum potential a cultivar possesses for producing dormant seeds can be revealed by determining the germination of seeds developed at 15°C and germinated at 15, 20, and 26°C.