Abstract:

[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.

Key words: Bothriochloa ischaemum, storage years, populations, seed vigour