新疆变色石竹土壤种子库特征及其对种子萌发的影响

Characteristics of Soil Seed Bank of Dianthus versicolor and Their Effects on Seed Germination

采用野外样方调查、种子鉴定及种子发芽等相结合的方法,对新疆变色石竹2个自然种群种子库进行研究,以期揭示变色石竹不同种群土壤种子库特征及与种群更新之间的关系。A种群分布于天山西部新源县境内海拔1 100m的砾石山坡,地理坐标为82°28′E,43°03′N,B种群分布于天山西部尼勒克县境内海拔2 093 m的山坡草地,地理坐标为84°05′14″E,43°43′23″N。结果表明,变色石竹种群土壤种子库比较丰富,平均密度为50粒/m2;A种群种子主要存在于枯枝落叶层及0～2cm土层中,占总量的92%;B种群种子主要存在于0～2cm及2～4cm的土层中,占总量的96%。种子萌发试验结果表明：室内萌发率显著高于自然种群萌发率,A种群的山坡上部自然种子萌发率最高,山坡上部、山坡中部、山坡下部和山坡底部室内萌发率显著高于自然萌发率（P〈0.01）。B种群的山坡中部自然种群种子萌发率最高,山坡上部、山坡中部、山坡下部和山坡底部室内萌发率显著高于自然萌发率,自然条件下,变色石竹以种子繁殖,土壤种子库是其自然更新及种群恢复的重要基础。

In this research,the seed bank of two natural populations of D.versicolor from Xinjiang were studied with methods of field sampling investigation,seed identification and seed germination so as to reveal the relationship between characteristics of soil seed bank of different populations and population regeneration.The results showed that the soil seed bank of D.versicolor population was relatively abundant,with an average density of 50grains/m2;the seeds of population A mainly existed in the litter layer or the soil layer of 0-2cm,accounting for 92%,while the seeds of population B chiefly existed in the soil layer of 0-2cm and 2-4cm,accounting for 96%.The result of seeds germination test showed that the indoor germination rates of population A and B were significantly higher than their natural germination rates（P〈0.01）,the natural germination rate of seeds of population A growing in the upper part of the hill was the highest.The indoor germination rates of the seeds growing in the upper part,middle part,lower part and at the bottom of the hill were significantly higher than their natural germination rates.This paper indicated that D.versicolor was propagated from seeds,and the soil seed bank was a basic necessity for the natural regeneration and population restoration of D.versicolor,which has provided theoretical foundation for exploring the natural regeneration mechanism and restoring the population.