贮藏年限对不同居群白羊草种子活力的影响

目的]探究贮藏年限对不同居群白羊草（Bothriochloa ischaemum）种子活力的影响。方法]采用收获于2017年、2018年、2019年及2020年的5个居群（代县、平鲁、平定、柳林和太谷）白羊草种子进行发芽试验，分析其发芽率、发芽指数、平均发芽时间及幼苗活力指数随贮藏年限的变化规律，探讨不同居群白羊草种子的耐贮藏性差异。结果]贮藏年限、居群及两者的交互作用对白羊草种子发芽率、发芽指数及幼苗活力指数存在极显著（P<0.01）影响。不同居群白羊草种子发芽率、发芽指数及幼苗活力指数随贮藏年限的增加均呈下降趋势。太谷居群白羊草种子收获当年以及贮藏1和2年的发芽率、发芽指数差异不显著（P>0.05），贮藏3年时显著（P<0.05）下降，幼苗活力指数随贮藏年限的增加无显著（P>0.05）变化；其他居群白羊草种子收获当年的发芽率、发芽指数及幼苗活力指数均显著（P<0.05）高于贮藏1、2、3年。柳林居群白羊草种子在收获当年的发芽指数、幼苗活力指数均高于其他居群，平均发芽时间低于其他居群，发芽率较高。贮藏年限对白羊草种子的平均发芽时间存在极显著（P<0.01）影响，平均发芽时间随贮藏年限的增加而延长，且居群对白羊草种子平均发芽时间也存在极显著（P<0.01）影响，但贮藏年限与居群的交互作用对白羊草种子平均发芽时间的影响不显著（P>0.05）。结论]不同居群白羊草种子活力均在收获当年保持较高水平，其中，柳林居群白羊草种子活力水平最高。太谷居群白羊草种子活力在贮藏3年内保持较高水平，耐贮藏性最好；而其他居群均不适合长期贮藏。

Effects of Storage Years on Seed Vigour of Bothriochloa ischaemum of Different Populations

Objective] The aim of the present study was to explore the effects of storage years on seed vigour of Bothriochloa ischaemum of different populations. Method] Bothriochloa ischaemum seeds of five populations （Daixian, Pinglu, Pingding, Liulin and Taigu） harvested in the years of 2017, 2018, 2019 and 2020 were used as materials for the germination tests, respectively. The changes in seed germination rate, germination index and average germination time, as well as seedling vigour index with the variations of storage years were characterized. The difference in storage durability of Bothriochloa ischaemum seeds of various populations were assessed. Result] The seed germination rate and germination index as well as seedling vigour of Bothriochloa ischaemum were all extremely significantly （P<0.01） impacted by storage years, populations and their interactions. With the extension of storage years, the seed germination rate and germination index as well as seedling vigour index of Bothriochloa ischaemum of different populations showed a downtrend. For Taigu population, while there were no significant （P>0.05） differences in germination rate and germination index among the seeds currently harvested and stored for 1 and 2 years, significantly （P<0.05） decreased germination rate and germination index were observed in the seeds stored for 3 years; the seedling vigour index had no significant （P>0.05） changes as storage years increased. For the other populations, the seeds currently harvested had significantly （P<0.05） higher germination rate and germination index as well as seedling vigour index in comparison to those stored for 1, 2 and 3 years. In the year of harvest, the Liulin population had higher seed germination index and seedling vigour index as well as lower average germination time compared with the remaining populations, and showed a higher germination rate. Storage years extremely significantly （P<0.01） affected the average germination time of Bothriochloa ischaemum seeds, and the average germination time was prolonged with the increase of storage years. Populations also extremely significantly （P<0.01） influenced the average germination time of Bothriochloa ischaemum seeds. However, the interactions between storage years and populations had no significant （P>0.05） effects on the average germination time of Bothriochloa ischaemum seeds. Conclusion] Different populations of Bothriochloa ischaemum seeds maintained a higher level of vigour in the harvest year, with Liulin population being the highest. The Taigu population exhibited the best storage durability, maintaining high levels of seed vigour within 3 years of storage. The other populations were unsuitable for storage over a long period.