不同抗旱性春小麦品种资源利用效率及其权衡

发布时间：2018-12-13 17:23

【摘要】：植物对资源的高效利用及权衡策略是植物生态学和农业生态学领域的研究热点问题之一。光能、水分和氮素作为植物生长的必需资源,其环境供给水平与植物获取能力、利用效率的关系,植物冠层与根系结构、生物量分配对水氮水平的响应等问题尚待进一步研究。本研究应用抗旱性不同的三个春小麦品种为材料,设置不同水分和氮素供应水平,通过田间试验探讨春小麦冠层、根系结构与功能、生物量积累与分配对水分和氮素水平的响应,分析了春小麦品种氮素、水分和光能利用率及其权衡关系。取得以下主要结果:(1)三个春小麦品种间表型(冠层高度、比叶面积、叶倾角、根长、根尖数、根平均直径、根体积、根表面积、根投影面积)可塑性有明显差异。比叶面积、叶倾角、可溶性糖、可溶性蛋白、脯氨酸与冠层氮素含量在冠层垂直水平上差异显著。抗旱性品种和尚头与西旱2号根系大、冠层高、叶片渗透调节物质含量高、蒸腾速率低,对土壤水分和氮素吸收和保持能力强。不抗旱性品种宁春4号群体株型紧凑、冠层氮素垂直分布梯度明显、光资源捕获利用能力强、光合电子流向光化学反应方向的分配比例高、净光合速率高。增加灌水和适量施氮(和尚头与西旱2号在施氮150kg·hm-2、宁春4号在施氮225kg·hm-2时)可以通过改变小麦冠层、根系结构功能,促进春小麦光能截获和水氮吸收能力的提高。(2)宁春4号繁殖分配、籽粒产量、灌溉水利用效率及产量构成因素(有效穗数、穗粒数、千粒重)明显高于抗旱品种。西旱2号生物产量及各器官生物量积累最大,光能利用效率最高。和尚头生物量水分利用效率最高。抗旱性品种和尚头与西旱2号对土壤水分敏感性低、对氮素敏感性高,不抗旱品种宁春4号相反。减少灌水对不抗旱品种的生物量水分利用效率提高效果明显,提高氮素水平对抗旱品种的生物量氮素利用效率和籽粒氮素贡献率更高。灌水量增加后,三个小麦品种生物量水分利用效率明显降低。增加施氮水平,小麦植株氮素获取量增加,氮素利用效率(氮素干物质生产效率、氮素收获指数、氮肥农学利用效率、氮肥偏生产力)显著下降。(3)氮素干物质生产效率与光能利用效率、生物量水分利用率极显著负相关,光能利用率与生物量水分利用率显著正相关。所以,春小麦氮素利用率与光能、水分利用效率间存在明显的权衡关系。本研究探讨了不同抗旱性小麦品种资源利用效率及其对水氮水平的响应,为更好地理解植物光能、水分与氮素利用效率间的权衡关系提供了科学依据,明确了有利于提高不同抗旱性品种资源利用效率的灌水和施氮水平,对绿洲灌区农业资源高效利用具有重要实践指导意义。
[Abstract]:The efficient utilization and tradeoff strategy of plant resources is one of the hot issues in plant ecology and agroecology. Light energy, water and nitrogen are essential resources for plant growth. The relationship between environmental supply level and plant acquisition capacity, utilization efficiency, plant canopy and root structure, and the response of biomass allocation to water and nitrogen levels need to be further studied. In this study, three spring wheat varieties with different drought resistance were used as materials, different water and nitrogen supply levels were set up, and the canopy, root system structure and function of spring wheat were studied through field experiments. The responses of biomass accumulation and allocation to water and nitrogen levels were analyzed. The utilization efficiency of nitrogen, water and light energy and their trade-offs were analyzed in spring wheat varieties. The main results were as follows: (1) there were significant differences in phenotype (canopy height, specific leaf area, leaf inclination, root length, root tip number, root mean diameter, root volume, root surface area, root projection area) among the three spring wheat varieties. Specific leaf area, leaf inclination, soluble sugar, soluble protein, proline and nitrogen content in canopy were significantly different at vertical level. The drought-resistant varieties had large root system, high canopy, high content of leaf osmotic regulator, low transpiration rate and strong ability to absorb and maintain soil water and nitrogen. Ningchun 4, a non-drought-resistant variety, has compact plant type, obvious vertical distribution gradient of nitrogen in canopy, strong ability to capture and utilize light resources, high distribution ratio of photosynthetic electron to photochemical reaction direction and high net photosynthetic rate. The increase of irrigation water and appropriate amount of nitrogen application (when applying nitrogen 150kg hm-2, Ningchun 4 at N 225kg hm-2) could change the structure and function of root system by changing the canopy of wheat. (2) the reproductive allocation, grain yield, irrigation water use efficiency and yield components of Ningchun No. 4 were significantly higher than those of drought-resistant varieties (number of effective panicles, number of kernels per ear, 1000-grain weight). The biological yield and biomass of each organ of Xihan 2 were the largest, and the light energy utilization efficiency was the highest. The biomass water use efficiency of Heshantou was the highest. Drought resistant cultivar HeShangtou and Xihan 2 had low sensitivity to soil moisture and high sensitivity to nitrogen, but the non-drought-resistant cultivar Ningchun 4 was opposite. The effect of reducing irrigation on the biomass water use efficiency of drought resistant varieties was obvious, and the increase of nitrogen level to the biomass nitrogen use efficiency and grain nitrogen contribution rate of drought-resistant varieties was higher than that of non-drought resistant varieties. The biomass water use efficiency of the three wheat varieties decreased significantly after the increase of irrigation amount. With the increase of nitrogen application level, the amount of nitrogen in wheat plants increased, and the nitrogen use efficiency (nitrogen dry matter production efficiency, nitrogen harvest index, agricultural efficiency of nitrogen fertilizer) was increased. (3) nitrogen dry matter production efficiency was negatively correlated with light energy use efficiency, biomass water use efficiency, and light energy use efficiency was positively correlated with biomass water use efficiency. Therefore, there is an obvious trade-off relationship between nitrogen use efficiency and light energy, water use efficiency of spring wheat. In this study, the resource utilization efficiency of wheat varieties with different drought resistance and their responses to water and nitrogen levels were discussed, which provided a scientific basis for better understanding of the trade-offs among plant light energy, water use efficiency and nitrogen use efficiency. It is clear that irrigation and nitrogen application level are beneficial to improve the resource utilization efficiency of different drought-resistant varieties and have important practical guiding significance for the efficient utilization of agricultural resources in oasis irrigation area.
【学位授予单位】：甘肃农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S512.12

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