兰州大学机构库 >生命科学学院
春小麦种群自疏指数的干旱效应及其气孔和光合基础研究
Alternative TitleEffects of Drought on Self-thinning Index and Its Stomatal and Photosynthetic Basis in Spring Wheat Population
张晓艳
Thesis Advisor王根轩
2003-05-29
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword春小麦 种植密度 土壤水分
Abstract植物种群自疏现象是植物种群生态学研究的重要内容之一 几十年来围绕自疏指数是否为-3/2进行了大量的研究 但是 这些研究基本上都是在水分条件较好的情况下进行的 也没有对不同水分条件下的自疏状况进行深入探讨 有研究表明 干旱条件下密度效应会有一定改变 因此 本文着重探讨干旱条件下自疏指数的变化及其气孔和光合基础 本实验以春小麦Triticum aestivum L. 为材料 设计2个水分处理和6个种植密度来进行研究 结果表明 1 干旱使平均个体根生物量-密度的自疏线显著降低 平均个体茎生物量-密度的自疏线虽然位于正常水分的下方 但是变得更陡 平均个体生物量-密度的自疏线略提高 土壤干旱条件下 千粒重 穗粒数和产量降低平均个体生物量和总生物量减小 随种植密度的升高 产量升高 但密度达到 1000 株·m-2以上时则不再发生明显变化 千粒重和穗粒数降低 平均个体生物量明显降低而总生物量增加 这说明 随种植密度的升高 春小麦种群竞争加剧 土壤干旱条件下 地上部的竞争减弱 自疏可能主要是因根竞争造成的 2 随种植密度的升高 气孔密度先增大后减小 气孔在叶片上的分布趋向均匀 干旱条件下 随种植密度的升高气孔密度及分布的变化趋势与正常水分条件下的一致 但趋势更为明显 说明种植密度增大导致气孔密度和分布的变化是单位土地面积内植物个体之间的竞争加剧造成的 干旱强化了密度效应 3 净光合速率 蒸腾速率 气孔导度均随种植密度的升高而降低胞间 CO2浓度先降低后升高 干旱条件下的变化趋势更为显著 说明水分亏缺突出了春小麦种群的密度效应
Other AbstractResearches on plant self-thinning are very important in plant population ecology. A large body of studies has been focused on whether self-thinning index is –3/2 or not, but most of the above work were performed under normal conditions and no further studies were done on self-thinning under different water conditions. It appeared that density effect would be different under water deficit conditions. So, the changes of self-thinning index and its correlations with stomata and photosynthesis were discussed in detail under drought condition here. Spring wheat (Triticum aestivum L.) was grown in six planting densities (1, 10, 100, 1000, 4000 and 10000 individuals·m-2) and two soil water levels (80±5% and 40±5% soil water capacity). The stomatal characters, photosynthetic characteristics, and yields were measured. The effects of drought on self-thinning, and its stomatal and photosynthetic basis were discussed. The yields increased with the increase of planting densities, while the weight of 1000-grain and the numbers of grains of a tiller decreased. Soil water deficit led to the decreases of yields, 1000-grain weight and number of grains of a tiller and weakened the speed that they changed with planting density increase. The mean individual biomass of lower planting densities was more than that of the higher ones, while for the total biomass, it was more for higher planting densities in the earlier lifetime and less in the later lifetime. Soil water deficit led to the decreases of both the mean individual biomass and total biomass, and weakened their change trends. Soil water deficit led to the increase of the self-thinning line of mean individual biomass vs. density, and it obviously heightened the line of shoot biomass vs. density, but significantly lowered the line of root biomass vs. density. It showed that the elevation of planting density promoted the competition of the populations, while drought weakened the competitions of the above ground part. And self-thinning was affected mainly by root competition in low soil water levels and shoot competition had no obvious effect on self-thinning. The planting densities not only affected stomatal densities but also stomatal distributions. Stomatal densities increased as the planting densities changed from 1 to 1000 individuals·m-2, then it decreased significantly. The maximum stomatal density was found in the leaf base, while the minimum, in the leaf apex. Stomatal distribution became more symmetrical...
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Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/221622
Collection生命科学学院
Recommended Citation
GB/T 7714
张晓艳. 春小麦种群自疏指数的干旱效应及其气孔和光合基础研究[D]. 兰州. 兰州大学,2003.
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