Increase of maize harvest index to improve water und nutrient use efficiency for a more sustainable crop production

提高玉米收获指数，提高水和养分利用效率，实现更可持续的作物生产

• 批准号: 405581090
• 负责人: Professorin Dr. Birgit Hütsch
• 金额: --
• 依托单位: Institut für Pflanzenernährung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405581090?language=en
• 关键词: Increase; maize; harvest; index; improve

The harvest index (HI = grain yield/total aboveground biomass) of many agricultural crops has been strongly increased during the last decades. However, the HI of maize has only marginally increased since the introduction of hybrids. In maize, opposite to other crops, a close positive correlation exists between biomass production and grain yield. However, the production of vegetative biomass in grain maize requires high amounts of water and nutrients. The increase of the HI may thus improve water and nutrient use efficiency, allowing a more sustainable production. In future, this will be particularly important as water resources become scarce, and as applications of fertilizers have to be reduced to meet environmental limits.We suggest two ways for improvement of maize HI: increase in kernel setting and decrease of vegetative shoot biomass. For better kernel setting, the proposed research focuses on the effect of salt stress and the role of auxins in grain development. Our research group was the first to measure plasma membrane H+-ATPase activity in kernels shortly after pollination. This enzyme is the key driver for hexose uptake from the apoplast into the developing kernels via H+ cotransport. Thus, in the applied project maize plants will be grown under field-like conditions in large containers and treated with elicitors of plasma membrane H+-ATPase activity (auxin, fusicoccin) to improve kernel setting. In the first year, the optimal dosage has to be determined, whereas in the second year additional application dates will be tested. In both years, two days after controlled pollination an intermediate harvest will be conducted and sugar concentrations and H+-ATPase activity parameters in apical and basal parts of the cob will be measured. At final harvest (maturity) yield parameters will be analyzed and water and nutrient use efficiencies determined. In the third year the apoplastic pH in the developing kernels will be measured in vivo, as it is directly affected by plasma membrane H+-ATPase activity.In a second approach the effect of reduced vegetative shoot growth on maize HI and resource use efficiencies will be tested. By application of a gibberellin biosynthesis inhibitor it will be tested whether it is possible to affect vegetative shoot and cob growth differently and thus break the strong correlation between both parameters. To test cultivar-inhibitor interactions, the optimal dosage of paclobutrazol, which has already shown positive effects, will be determined with six maize cultivars. Application time will be varied as well in order to find the optimum growth stage for the treatment. Eventually three cultivars, which performed best in HI and grain yield, will be chosen and the effect of reduced fertilizer amendment on nutrient use efficiencies will be tested.

许多农作物的收获指数（HI =谷物产量/地上总生物量）在过去几十年中大幅增加。然而，自引进杂交种以来，玉米的HI仅略有增加。与其他作物相反，玉米的生物量生产与粮食产量之间存在密切的正相关关系。然而，谷物玉米中营养生物量的生产需要大量的水和营养。因此，HI的增加可以提高水和养分的利用效率，允许更可持续的生产。在未来，这将是特别重要的，因为水资源变得稀缺，并作为化肥的应用必须减少，以满足环境limits.We建议两种方法来改善玉米HI：增加在仁设置和减少营养枝生物量。为了更好地结实籽粒，建议的研究重点是盐胁迫的影响和生长素在籽粒发育中的作用。本研究组首次在授粉后不久测定了籽粒质膜H+-ATPase活性。这种酶是通过H+共运输将己糖从质外体吸收到发育中的籽粒中的关键驱动力。因此，在所应用的项目中，玉米植株将在大容器中在类似田间的条件下生长，并用质膜H+-ATP酶活性的激发子（生长素、梭孢菌素）处理以改善籽粒结实。在第一年，必须确定最佳剂量，而在第二年，将测试额外的应用日期。在这两年中，控制授粉后两天的中间收获将进行和糖浓度和H+-ATP酶活性参数的顶部和基部的穗轴将被测量。在最终收获（成熟）时，将分析产量参数，并确定水和养分利用效率。在第三年，将在体内测量发育中的籽粒的质外体pH，因为它直接受质膜H+-ATPase活性的影响。通过施用赤霉素生物合成抑制剂，将测试是否可能不同地影响营养芽和穗轴生长，从而打破两个参数之间的强相关性。为了测试品种抑制剂的相互作用，多效唑的最佳剂量，这已经显示出积极的影响，将确定与六个玉米品种。施用时间也将变化，以找到处理的最佳生长阶段。最后，将选择在HI和籽粒产量方面表现最好的三个品种，并测试减少肥料添加剂对养分利用效率的影响。