研究了画眉草种子在不同贮藏条件以及光照、温度和降雨等环境因素下的萌发对策.结果表明,画眉草新种子具有较强的内在休眠;4个月的干藏和冷藏处理对解除种子休眠作用不明显,但较长时间的贮藏(干藏1年)则能促进种子成熟.画眉草种子在光照和黑暗条件下都能萌发,但较强的光照更有利于种子萌发.种子萌发适宜温度是28 ℃,温度升高和降低都会导致画眉草种子萌发率下降;变温条件下(16~28 ℃)种子萌发率高于恒温28 ℃条件,但两个处理间的萌发率没有显著差异.种子萌发降雨阈值是10 mm,种子萌发率和萌发持续时间均随降雨量的增加而增加.画眉草种子具有迅速萌发和推迟萌发时间超过1年以上两种萌发对策.根据种子形态特征和萌发策略,推断画眉草具有持久土壤种子库.
The study on the germination strategy of Eragrostis pilosa under different storage and environmental conditions showed that freshly collected E.pilosa seeds had a stronger innate dormancy.Chilling and dry storage for 4 months had no obvious effect on releasing from dormancy,while longer time storage could facilitate seed maturation.The seeds could germinate either in light or in darkness,and stronger light was in favor of germination.The optimal temperature for germination was 28 ℃,while higher or lower temperature could result in the decrease of germination.The germination percentage of seeds under changed temperature (16 to 28 ℃) was higher than that under constant temperature (28 ℃),but with no significant difference.The critical amount of rain for seed germination was about 10 mm,and the germination percentage and duration all increased with increasing rainfall.E.pilosa had two germination strategies,i.e.,quick germination and dormancy for more than one year.Based on the seed morphological characters and germination strategies,it could be concluded that E.pilosa had a persistent soil seed bank.
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