9种禾本科草本植物的耐旱能力

草本植被过滤带在控制农田氮磷面源污染方面起着重要的作用,但在北方地区其生长易受春季干旱的影响。为了筛选农田氮磷截留草地过滤带适宜草种,本研究通过室内水分控制试验对9个多年生候选草本植物的耐旱能力进行了评价研究。结果表明,1)9个植物材料的生长特性存在明显的差异,黑麦草(Lolium perenne)和新麦草(Psathyrostachys juncea)分蘖能力最强,偃麦草(Elytrigia repens)两个品种生长速度最快;2)干旱胁迫下9个植物材料的分蘖能力和试验初期的茎生长速率受到了限制,因而生物量受到了影响,但在中度和重度干旱胁迫下,狼尾草(Pennisetum alopecuroides)、京草1号偃麦草和京草2号偃麦草分蘖数显著高于其它植物。3)干旱胁迫下,京草1号根系长度显著高于对照,柳枝稷(Panicum virgatum)根长与根表面积较对照均呈现增加的趋势。4)9个植物材料耐旱性能顺序为狼尾草京草2号柳枝稷细叶芒(Miscanthus sinensis)无芒雀麦(Bromus inermis)京草1号披碱草(Elymus dahuricus)和黑麦草新麦草。

Drought tolerance of nine types of herbal grasses

Establishing perennial herbaceous vegetation buffer adjacent to a stream is considered to be an effective management to prevent nitrogen and phosphorus losses in croplands.In northern China,however,growth of herbaceous vegetation,such as herbal grasses,is affected by drought.In this study,a drought resistance experiment was conducted to evaluate nine grass materials (Pennisetum alopecuroides.Panicum virgatum,Miscanthus sinensis,Lolium perenne,Bromus inermis,Psathyrostachys juncea,Elymus dahuricus,and Elytrigia repens) under water stress during tillering stage.The results showed:1) The growth characteristics of the nine grasses were significantly different.The tiller of L.perenne and P.juncea was the best,whereas the growth rate of E.repens was fast among these nine grasses.2) The tillers and growth of all nine grasses were affected by drought,reducing their biomass.At the same time,under medium and heavy drought stresses the tiller number of P.alopecuroides and E.repens was significantly higher than that of other grasses.3) The root length of Beijing No.1 (E.repens) was significantly greater relative to the control.The root length and surface area of P.virgatum also increased.4) The drought-tolerance of the nine grasses was in the following order:P.alopecuroides ＞Beijing No.2 (E.repens) ＞ P.virgatum ＞ M.sinensis ＞ B.inermis ＞ Beijing No.1(E.repens)＞E,dahuricus and L.perenne＞P,juncea.