不同胁迫条件对滇龙胆种子萌发的影响

目的]探讨环境胁迫对不同贮藏条件滇龙胆种子萌发的影响,为滇龙胆人工栽培和规范化种植提供指导.方法]以不同年份、不同贮藏方式滇龙胆种子为材料,探讨不同pH、水分胁迫和茶叶水提液对种子发芽率、萌发时间和胚芽长度的影响.结果]干藏1年种子在所有处理下均未发芽.在pH为7.0时,冷藏1年和当年种子发芽率最高（71.0％和58.5％）,胚芽长度最长（5.46和4.90 mm）.在5％ PEG处理下,冷藏1年和当年种子发芽率最高（73.0％和60.0％）;PEG对种子胚芽长度的抑制作用最明显;10％～15％ PEG对当年种子的萌发时间影响显著;在相同水分胁迫条件下,冷藏1年种子的发芽率均高于当年种子,而平均萌发时间均显著低于当年种子.在茶叶水提取物处理中,冷藏1年和当年种子的发芽率和胚芽长度均随茶叶水提取物质量体积分数的上升而下降,种子发芽率、萌发时间和胚芽长度均以对照最高;茶叶水提取物对当年种子的化感作用更明显.结论]弱酸、适度水分胁迫环境有利于滇龙胆种子萌发,低质量体积分数的茶叶水提取物对滇龙胆种子化感作用较小,冷藏可以打破滇龙胆种子的休眠.

Impact of different stress conditions on seed germination of Gentiana rigescens

Objective]The impacts of environmental stress on seed germination of Gentiana rigescens Franch. ex Hemsl. under different storage conditions were investigated to provide references for its artificial cultivation and standardized planting. Method]In this study, germination rate, mean germination time and plumule length of G. rigescens seeds with different harvest years and different storage conditions were tested under different treatments （pH, water stress and tea leaves extract liquid）. Result]The results showed that, after dry storage for one year, G. rigescens seed could not germinate under any treatment. For the seeds after cold storage for one year and new seeds, the highest germination rate （71.0% and 58.5%） and plumule length （5.46 and 4.90 mm） were found at pH 7.0, and the highest germination rate （73.0% and 60.0% ） was found when treating at 5% PEG. PEG had the most obvious inhabitation on plumule length. The 10%-15% PEG significantly affected the germination time of new seeds. Under the same water stress conditions, the germination rate of the seeds after cold storage for one year was higher than that of the new seeds, while the mean germination time of the seeds after cold storage for one year was remarkably lower than that of the new seeds. In the treatment of aqueous extract of tea, the germination rate and plumule length of G. rigeseens seeds after cold storage for one year and new seeds decreased with increasing extract concentration of tea. The germination rate, germination time and plumule length of G. rigescens seeds after cold storage for one year and new seeds were lower than those of the control. The aqueous extract of tea had stronger allelopathic effects on new seeds. Conclusion ] Weak acid and moderate water stress could improve the seed germination of G. rigescens. Low concentrations of tea leaves extract liquid had weak allelopathic activity on G. rigescens seeds, and cold storage condition could break seed dormancy of G. t~gescens.