Intra- and Inter-Specific Variation of Dormancy in the Seeds of Triticum and Aegilops

Abstract

In the seeds of wild type inTriticumandAegilopsdeveloped dormancy more strongly than the cultivated type in the diploid, tetraploid and hexaploid inTriticum. The dormancy in the seeds of cultivated type in the tetraploid and hexaploid widely varied not only with the difference in species, but also with the harvest year. The dormancy in the seeds of wild type, however, is hardly influenced by the environmental factors. The dormancy inTriticumandAegilopsseeds is released with the progress of after-ripening. The aged seeds ofTr. compactum (AABBDD, cultivated), Tr. macha (AABBDD, cultivated), andTr. aestivum (AABBDD, cultivated) with 48 months after harvest showed higher germination percentage than the seeds ofTr. boeoticum (AA, wild), Tr. dicoccoides (AABB, wild), Tr. timopheevi (AAGG, cultivated), Ae, bicornis (SbSb, wild) andAe, squarrosa (DD, wild) . The effects of GA₃or thiourea on germination in the seeds ofTriticumandAegilopscan be divided into two functions: 1) dormancy-releasing effect on dormant seeds, and 2) stimulating effect on aged seeds which have reduced their vitality.