盐胁迫和温度对桑树种子萌发及幼苗生长的影响

Effects of Salt Stress and Temperature on Seed Germination and Seedling Growth of Morus alba

以16年生桑树种子为试验材料,研究了不同NaCl浓度和温度对种子萌发、幼苗生长及根系生长的影响。结果表明:随盐浓度增加,发芽率、发芽指数、活力指数、幼苗干质量、根干质量和根冠比、根长和根表面积降低,平均发芽时间和根平均直径增加。随温度的上升,发芽率和发芽指数逐渐升高,平均发芽时间变小,但幼苗生物量、根系生物量、根冠比、根长和根表面积都是先增加再降低,30℃时最大。NaCl浓度和温度在平均发芽时间、根系生物量和根冠比上有着显著的交互作用,适度的高温缓解了桑树种子萌发时的盐胁迫程度。幼苗生物量与根系生物量、根冠比、根长和根表面积成极显著正相关,根系生长是反应幼苗受胁迫的敏感指标。

Seeds from 16-year-old Morus alba trees were used to investigate the effects of NaCl concentrations and germination temperatures on seed germination,seedling growth and root development.Results showed that the germination percentage,germination index,vigor index,seedling biomass,root biomass,root/shoot ratio,root length and root surface area decreased with the increase of salt concentration,mean germination time and root diameter increased.With the increase of temperature,G and GI increased,MGT decreased,but SB,RB,R/S,RL and RSA increased first and then decreased,and reached the maximum at 30℃.NaCl concentration and temperature had significant interaction on MGT,RB and R/S,and the appropriate increase of temperature alleviated the salt stress of the above indexes.SB was significantly positive correlated with RB,R/S,RL and RSA,and root growth was a sensitive index to reflect the stress of seedlings.