【摘要】 采用聚乙二醇人工模拟水分胁迫进行种子发芽试验,研究了青檀、朴树和榔榆3个树种种子在干旱逆境下的种子发芽和成苗特性。结果表明,水分胁迫下3个树种的种子发芽率、成苗率、发芽速率和萌发幼苗胚根、胚轴伸长以及幼苗含水量均随环境水势的降低而下降,种子从发芽到成苗阶段对水分亏缺最敏感。3个树种种子发芽能忍耐的最低环境水势分别为-0.49、-0.32MPa和-0.15MPa,种子成苗能忍耐的最低环境水势分别为-0.32、-0.32MPa和-0.15MPa。水分胁迫解除后,具有生活力的种子能够恢复发芽,但水分胁迫对种子发芽的影响具有后续作用。3个树种种子发芽对水分胁迫的适应策略主要表现为耐旱发芽和避逆发芽。更多还原

【Abstract】 The seed germination and seedling establishment characters of Pteroceltis tatarinowii,Celtis sinensis and Ulmus parvifolia were studied by germination test under water stress condition(simulated by polyethylene glycol(PEG)).The results indicated that the germination rate,seedling establishment rate,germination speed,length of embryonal root and embryonal axis as well as seedling water content of three tree species were decreased with decreasing environment potential. It was most sensitive period from seed germination to seedling establishment to water stress. The lowest environment potential for seed germination of Pteroceltis tatarinowii,Celtis sinensis and Ulmus parvifolia was -0.49 MPa,-0.32 MPa and -0.15 MPa respectively,and the lowest environment potential of seedling establishment was -0.32 MPa,-0.32 MPa and -0.15 MPa respectively. The vigor seeds could germinate again after derogating water stress,but the effects of water stress to seed germination existed hysterotely. The adaptive strategies for seed germination of three tree species to water stress mainly displayed drought tolerance germination and drought avoidance germination.更多还原