种植密度和施氮水平对垂穗披碱草生物量分配的影响

Reproductive allocation of Elymus nutans under different planting densities and nitrogen fertilizing treatments

基于盆栽试验,研究海北高寒地区垂穗披碱草(Elymus nutans)生长特性、生殖分配格局对不同种植密度和不同施氮水平处理的响应。结果表明,1)不同种植密度垂穗披碱草的株高、叶长、穗长、分蘖数及各器官生物量均表现出竞争―密度效应;各器官生物量分配规律均受密度效应影响,且生殖生物量分配在中低密度(20粒·m-2)下达最大值(10.46%)。2)高氮肥(2g·m-2)对垂穗披碱草各器官生物量影响较大,氮肥作用后对垂穗披碱草生殖生物量分配的影响表现先增大后减小的趋势;3)相关性分析表明,密度、氮肥单因子作用下株高、叶长、穗长、分蘖数及各器官生物量之间均呈极显著(P<0.01)正相关。4)线性回归分析表明,密度、氮肥单因子处理下,各器官的资源分配方面都存在"此消彼长"的权衡关系。

A pot experiment was conducted to study the response of the growth characteristics,reproductive allocation pattern of Elymus nutans to competition density and nutrient addition.The plant height,leaf length,panicle length,tiller number and each organ biomass of E.nutans had competition-density effects under different planting densities.Biomass allocation of each organ were constrained by the density and the reproductive biomass allocation reached the highest of 10.46% under lower density(20seed·m-2).There were significant effects of high nitrogen fertilizer on each organ biomass.Meanwhile,the effects of nitrogen fertilizer on reproductive biomass showed the trend of the inverted'V'type.Each growth index of E.nutans was significantly positive(P<0.01)correlated with each other under individual treatment of planting density or nitrogen fertilizer.There was'shift'trade-off relationship for resource allocation of each organ of E.nutans.