摘要
以中国特有种沙芥[Pugionium cornutum(L.)Gaertn.]和濒危种斧形沙芥(Pugionium dolabratum Max-im.)的种子为研究材料,利用自然生境的沙土在室内进行种子萌发人工模拟试验,研究沙芥和斧形沙芥种子萌发、幼苗出土和幼苗生长对土壤含水量的适应性。结果表明:沙芥和斧形沙芥果实适宜萌发的土壤含水量范围均为6%~12%,适宜出苗的土壤含水量范围均为6%~16%。当土壤含水量低于2%时,果实不能萌发;当土壤含水量低于3%时,幼苗不能出土定居;当土壤含水量为6%~12%时,最有利于幼苗的生长。当土壤含水量分别为3%~8%和4%~8%时,沙芥和斧形沙芥植株根冠比最大。因此,沙芥和斧形沙芥种子萌发机制对沙生环境有着极强的适应性;植株将更多的同化物用于根系生长,以吸收更深层次的水分,从而适应含水量低的土壤。
Pugioniurn cornutum is a special species in China and Pugionium dolabratum was listed an en- dangered species in 1992. Took sand from the natural habitat of P. dolabratum and used for indoor artificial simulation test, we investigated the adaptation of seed germination, seedling emergence and seedling growth in P. cornutum and P. dolabratum to sand moisture content. Results showed the optimal sand moisture con- tent for seed germination was from 6% to 12%for both P. cornutum and P. dolabratum. The optimal sand moisture content for seedling emergence was from 6%to 16%. When sand moisture content was under 2%, seeds could not germinate; when sand moisture content was under 3 %, seedling could not emerge and settle. The optimal sand moisture content was from 6% to 12% for P. cornutum and P. dolabratum's seed- ling development. From 3 % to 8 % for P. cornutum and from 4 % to 8 %, for P. dolabratum have their sig- nificantly highest root-top ratio. The seed germination mechanism of P. cornutum and P. dolabratum has strong adaptability to sand environment. In order to adapt to low sand moisture content, seedling allocated more biomass to root to absorb deeper level of water.
出处
《西北植物学报》
CAS
CSCD
北大核心
2012年第2期355-361,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家自然科学基金项目(31160393
30460080
30260067)
内蒙古自然科学基金项目(20038025013)
内蒙古人才基金项目
关键词
毛乌素沙地
十字花科
沙芥属
沙芥
斧形沙芥
种子萌发
土壤含水量
Mu Us Sandy Land
Cruciferae
Pugionium Gaertn.
Pugionium cornutum
Pugionium dolabraturn
seed germination
sand moisture conlent