Germination potential of Sinapis alba seedscollected 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 seedlings than seeds collected in northern regions, where a more normal level of rainfall occurs. These results were obtained when seeds were germinated on germination paper, sterile sand or naturally infested soil. The presence of seed and/or soilborne pathogenic fungi did not seem to play a role in the decrease of germination. The inability to germinate resulted from dormancy, since exogenous GA3 stimulated seed germination. The intensity of dormancy depended on the origin of the seeds, being deeper in seeds which originated from the southern part of Israel than in those collected in the north. The dormancy of seeds collected at Saʹad was expressed over a wide range of temperatures, while that of seeds collected at the Maʹabarot, Bet Dagan and Quiryat Gat stations was expressed only at high temperatures (30°C).