土壤水分和种子大小对梭梭种子萌发、出苗和幼苗生长的影响

采用室内试验研究不同土壤含水量及种子大小对梭梭种子萌发和出苗及幼苗生长的影响。结果表明,除土壤含水量2%的处理时小粒种子不能萌发外，其他水分条件下大、小粒种子均可萌发，并均出现随含水量增加萌发率逐渐增大的趋势，含水量为30%时大、小粒种子均出现最大值。土壤水分含量>8%时，大、小粒梭梭种子均可实现快速萌发，萌发速率间无显著差异，但土壤含水量显著影响大、小粒种子的萌发指数及活力指数，两者呈随含水量增加而先增大后降低的趋势，在含水量为15%时达最大值。土壤含水量为2%和30%的处理中梭梭种子即使萌发但幼苗也难以存活。土壤含水量对大、小粒种子幼苗苗高、根长及生物量的影响与成活率相似。

Effects of Soil Moisture and Seed Size on the Germination,Sprouting and Sapling Growth of Haloxylon ammodendron

This paper studied the effects of soil moisture and seed size on the germination,sprouting and sapling growth of Haloxylon ammodendron in the laboratory.The results showed that except that the seeds with small size could not geminate under 2% moisture content,all the seeds either with small or big sizes could germinate normally under other moisture conditions,and the germination rate increased with moisture content.The maximum germination rates of both big and small sized seeds appeared when the moisture content was 30%.When the moisture content was higher than 8%,both the big and small-sized seeds could germinate fast without significant differences in germinate rates.Soil moisture presented significant effects on the germination index and vital index of both big and small-sized seeds with a trend of increasing first and then decreasing,and reached the maximum when moisture content was 15%.The effects of moisture content on sapling height,root length and biomass were similar with that of the survival rate.