水分胁迫对豌豆种子萌发和幼苗生长发育的影响

利用PEG溶液(水势梯度为0～-0.50 MPa)模拟水分胁迫,研究了协豌一号种子萌发能力的变化及对萌发环境的最低水分需求。结果显示,PEG水分胁迫通过限制种子有效水分的吸收而抑制其萌发,且随着胁迫强度的增加,萌发能力减弱,主要表现为:萌发率、吸水速率、萌发活力、萌发胁迫指数随胁迫强度的增加而下降,根芽比则随之增加。环境水势对发芽率和种子吸水能力的影响不一致,表现为在PEG溶液梯度为-0.50 MPa时,其显著低于对照(P<0.05),其余梯度下差异不显著;PEG各处理梯度下萌发活力、萌发胁迫指数、根芽比、幼苗鲜质量及物质贮藏转运率与对照相比,差异显著(P<0.05)。豌豆苗期对水分的变化较为敏感,高浓度PEG会抑制其生长发育。

Seeds Germination Characteristics and Drought Tolerance of Pea Seedling under Water Stress

We investigated the seeds germination capability and the minmiunm water requirment in pea cultivars Xiewan 1 under water stress mimicked by PEG-6000 solution(Ψw=0～-0.50 MPa).The results showed that the inhibition of seed germination capability was dependent on impairing water efficient uptake under PEG stress,including declines of germination ratio,water content,vigor index and germination stress index and increase of radicle to embryo ratio and so on.Especially,germination capability was more weakened when water stress changed more severe.There were different responses of the accumulated germination and seed water uptake of pea seedlings to external water potential,indicating that between-0.50 MPa and CK treatment there were significant difference(P<0.05),but others not significant;GI,VI,R/P,GSI and TR of pea seeds were significant different under PEG treatment(P<0.05).