不同建植密度对松嫩平原肥披碱草无性系种群构件结构的影响

Effect of different estabished densities on module structure of Elymus excelsus clone populations in Songnen Plain of China

采用大样本随机挖掘整个分蘖丛的取样方法,对松嫩平原栽培条件下实生苗建植的5个密度和分蘖苗建植的2个密度的肥披碱草无性系种群构件数量和生物量结构以及生殖分配进行了定量分析,以揭示不同建植密度肥披碱草无性系种群的生长规律。结果表明,在9月末停止生长期,经过2个生长季的营养繁殖,在第二个生长季末,不同建植方式的种群生殖株、营养株、冬性苗数量和生物量,RAⅠ(生殖分蘖株生物量与地上部分构件总生物量的比值)、RAⅡ(花序生物量与地上部分构件总生物量的比值)以及RAⅢ(成熟饱满子粒生物量与地上部分构件总生物量的比值),以及地上部分构件总数量和生物量均随密度升高呈下降的趋势(P<0.05);与高密度相比,低密度肥披碱草种群将更多的资源分配给生殖分蘖株、花序和成熟饱满子粒等有性生殖构件。同为密度45株·m-2,分蘖苗建植的种群生殖分蘖株数量和生物量、RAⅠ、RAⅡ、RAⅢ均高于实生苗建植的种群(P<0.05);而营养分蘖株、冬性苗数量和生物量,地上部分构件总数量皆小于实生苗建植的肥披碱草种群(P<0.05);两种建植方式地上部分总生物量之间没有显著差异(P<0.05)。3种构件中,实生苗建植的5个密度数量和生物量皆以冬性苗所占比率最大,而分蘖苗建植的2个密度数量以冬性苗所占比率最大,而生物量以生殖株所占比率最大。

Number structure,biomass structure of modules and reproductive allocation of five densities （16,25,45,100,400 plants·m-2） established by seedlings and two densities （9,45 plants·m-2）established by tillers were quantitatively analyzed by the sample method of digging up the whole tiller tuft randomly in Puccinellia tenuifora clones in its growth stopping period at the end of September under the cultural conditions to disclose growth rule of of Elymus excelsus clone populations different estabished densities by large sample in Songnen Plain.The results showed that numbers and biomasses of reproductive tillers,vegetative tillers and winterness seedlings,above-ground biomasses,and RAⅠ,the ratio of biomass of reproductive tiller to total biomass of above-ground module,and RAⅡ,the ratio of spike biomass to total biomass of above-ground module,and RAⅢ,the ratio of ripe seed biomasses to total biomass of above-ground module,and total number and biomass of above-ground module of clones in two eatablishment ways all decreased with increasing density （P0.05） at the end of the second growing season after two growth seasons of vegetative reproduction.More resources were allocated to reproductive modules,such as reproductive tillers,spikes and ripe seeds in low densities in contrast with high densities.Some quantity characters of the clones in the same density,which was 45 plants·m-2,in the two establishment ways were different.The numbers and biomasses of reproductive tillers,RAⅠ,RAⅡ and RAⅢ of the clones established by younger tillers were all higher than the ones of clones established by seedlings （P0.05）,and numbers and biomasses of vegetative tillers and winterness seedlings,total number of above-ground module were lower than that of clone established by seedlings （P0.05）.There were no differences in biomass of above-ground module between the two establishment ways （P0.05）.Percent of winterness seedling of number and biomass were all the largest in five densities,while percent of winterness seedling of number and reproductive tiller of biomass were all the largest in two densities established by tillers.