黑果枸杞种子萌发及幼苗生长对盐胁迫的响应

研究不同浓度(0、1、2、3、6、9、14、18g.L-1)的盐溶液(NaCl、MgSO4、盐渍土壤)对河西走廊中部荒漠边缘的黑果枸杞种子吸胀、萌发和幼苗生长的影响,并观察胁迫解除后种子的反应。结果表明:黑果枸杞种子吸胀速率随NaCl、MgSO4和土壤溶液浓度的增大呈先升后降的趋势,吸水速度随胁迫时间的延长而减慢;种子萌发率随3种盐浓度的增大而降低,盐胁迫解除后种子仍具有较高的萌发率;发芽指数、活力指数、根长、下胚轴随3种盐浓度的增大而降低或先升后降,根轴比随盐胁迫的增强先升后降;随3种盐浓度的增大,种苗损害率增大,3种盐的胁迫效应依次NaCl>MgSO4>盐渍土壤溶液。黑果枸杞种子萌发和幼苗生长对NaCl胁迫较为敏感,其耐受的临界阈值是6g.L-1;种子萌发能耐受较高浓度的MgSO4的胁迫,幼苗生长对MgSO4胁迫较敏感,其耐受的临界阈值是9g.L-1;种子萌发和幼苗生长对生境盐渍土壤具有较强的耐受能力和适应性。

Responses of seed germination and seedling growth of Lycium ruthenicum to salt stress

Lycium ruthenium seeds were collected from the desert edge of middle Hexi Corridor,Gansu Province of Northwest China to study their water absorption and swelling rates and germination potential and the seedling’s growth in 0,1,2,3,6,9,14,and 18 g·L-1 of NaCl,MgSO4,and salted soil solutions,and to observe the responses of the seeds after the stress released.With the increasing salt concentration,the water absorption and swelling rates of the seeds decreased after an initial increase,and the water absorption rate was slowed down with the increasing salt stress duration.The seed germination percentage decreased with increasing salt stress,but still maintained at a higher level after the stress released.The seed germination index,seed vigor index,root length,and hypocotyl length decreased or decreased after an initial increase,and the ratio of root length to hypocotyl length increased first and decreased then with the increasing salt stress.The damaged percentage of the seedlings increased with the increasing salt concentration,and the stress effect was in the order of NaCl > MgSO4> salted soil solution.The seed germination and seedling growth of L.ruthenium were more sensitive to NaCl stress,with the tolerance threshold being 6 g·L-1.The seed germination could tolerate higher concentration MgSO4 stress,but the seedlings growth was more sensitive to MgSO4 stress,with a threshold of 9 g·L-1.Both the seed germination and the seedlings growth had higher tolerance and adaptability to salted soil.