GERMINATION POTENTIAL OF SINAPIS-ALBA SEEDS COLLECTED IN ISRAEL

Seeds of Sinapis alba collected from the dry and hot southern regions of Israel had a lower per cent of germination and of emerging seedling s than seeds collected in northern regions, where a more normal level of rainfall occurs. These results were obtained when seeds were germin ated on germination paper, sterile sand or naturally infested soil. Th e presence of seed and/or soilborne pathogenic fungi did not seem to p lay a role in the decrease of germination. The inability to germinate resulted from dormancy, since exogenous GA(3) stimulated seed germinat ion. The intensity of dormancy depended on the origin of the seeds, be ing deeper in seeds which originated from the southern part of Israel than in those collected in the north. The dormancy of seeds collected at Sa'ad was expressed over a wide range of temperatures, while that o f seeds collected at the Ma'abarot, Bet Dagan and Quiryat Gat stations was expressed only at high temperatures (30 degrees C).