四种沙埋深度对羊草种子出苗和幼苗生长的影响

Effects of sand-burial depth on Leymus chinensis seedlings emergence and growth

模拟羊草种子自然埋藏深度状况,设计了0、1、2和3cm共4种沙埋深度实验,研究了其出苗率及幼苗生长对沙埋深度的响应。结果表明,羊草种子出苗率随埋深的增加呈下降趋势,0cm时出苗率最高为89.3%,1和2cm时分别为81.5%和78.5%,3cm时最低(73.5%),与前三者具有显著差异。埋深对地上株高生长动态的影响主要表现在,播种后25d,0～2cm处理的羊草幼苗地上株高均高于3cm处理;播种后36d,4种处理的地上株高没有显著差异。此外,随着埋深的增加,羊草幼苗的根长、根数、根冠比呈先上升后下降趋势,叶片数呈下降趋势,绝对株高则呈上升趋势。表明1～2cm沙埋深度更适宜于羊草种子出苗及幼苗生长,而0或3cm埋深不利于其出苗和幼苗生长。

To investigate the effects of burial depth on the Leymus chinensis seedlings emergence and growth under natural conditions, a simulation study was conducted with four sand-burial depths （0, 1,2 and 3 cm）. The results showed that the seedlings emergence rate decreased with increasing burial depth, being 89.3%, 81.5%, 78.5% and 73.5% when the burial depths were 0, 1, 2 and 3 cm, respectively. During the first 25 days of growth, the aboveground plant height was higher in the treatments of 0-2 cm burial depth than in that of 3 cm burial depth, but no significant difference was observed among the four treatments by the end of the experiment （36 days after growth）. With the increase of burial depth, the root length and number and the root/ shoot ratio increased first but decreased then, leaf number decreased, and seedlings absolute height increased. It could be concluded that a sand-burial depth of 1-2 cm could be more suit-able to the L. chinensis seedlings emergence and growth, while the burial depths of 0 and 3 cm could be unfavorable to the emergence and growth.