中文摘要：

以中国特有种沙芥和濒危种斧形沙芥为试材,研究了人工控制的6个沙埋深度和4个供水量处理对沙芥与斧形沙芥幼苗出土的影响。结果表明：沙埋不同深度的沙芥、斧形沙芥出苗与供水量密切相关。当供水量为毛乌素沙地6月份平均降雨量的50%（22.5mm）时,沙埋各深度的果实都不能出苗;当供水量为毛乌素沙地6月份平均降雨量（50mm）时,浅层的沙芥（1-4cm）和斧形沙芥（1-2cm）均能顺利出苗;当供水量为毛乌素沙地7月份平均降雨量（100mm）时,沙芥沙埋1-4cm和斧形沙芥沙埋0-6cm均能出苗;当供水量为毛乌素沙地7月份平均降雨量增加50%（150mm）时,沙芥1-8cm和斧形沙芥0-8cm均能出苗。沙芥出苗速率随供水量的增加而增加,其中供水量为135mL时出苗最快,沙埋2cm出苗最快,且随着沙埋深度的增加,出苗时间推迟。斧形沙芥在供水量90mL出苗较快,出苗时间等于或早于供水量135mL,1cm沙埋深度出苗最快。结合毛乌素沙地降雨特点与该试验结果,沙埋1.0-2.0cm和100mm以上月平均降雨量是沙芥和斧形沙芥自然条件下出苗较好的重要条件。

英文摘要：

Taking P.cornutum a special species in China and P.dolabratumlisted an endangered species in 1992 as materials,the effect of water supplying and sand burial on seedling emergence of P.cornutumand P.dolabratum were studied,a set of experiments were conducted under six depths of sand burial and four kinds of continual water supply.The results showed that the buried depth was closely correlated with water supply.When the water supply was 22.5mm that would be 50%of the average rainfall of Mu Us Sandy Land in June,the seeds couldn＇t emerge.When the water supply was 50mm（the average rainfall in June）,the seeds could germinate on the superficial layer of P.cornutum（1-4cm）and P.dolabratum（1-2cm）.When the water supply was 100mm（the average rainfall in July）,a few seeds could emerge well in 1-4cm of P.cornutumand 0-6cm of P.dolabratum.When the water supply was 150mm（50%of water supply of the average rainfall in July）,the seeds could emerge in 1-8cm of P.cornutumand 0-8cm of P.dolabratum.The emergence rate of P.cornutum would be increase with water supply increasing.For P.cornutum,there was the fastest emergence rate in 135 mL in all sand burial,and 2cm in all the buried depth.For P.dolabratum,90 mL was faster than 135 mL in the water supply of the seedling emergence,and 1cm was the fastest seedling emergence in all sand burial depth.Based on our experiment results and precipitation characteristics of the Mu Us sandy land,there would be the important conditions for P.cornutum and P.dolabratumin 1.0-2.0cm buried depth and 100 mm average rainfall.