水分调控对延迟栽培葡萄土壤碳源代谢及果实品质的协同作用机理

Extensive irrigation, poor quality of grape and degraded environment of soil microorganism are critical issues existed in the greenhouse delay-cultured grape in cold region of China. Based on the PCR and Biolog micro plate techniques, the effect mechanism of irrigation water on metabolic activity and carbon source utilization of rhizosphere microbial community is studied. In addition, from the point of the entire plant carbon metabolism, the effect mechanism of irrigation water on amount and distribution of carbon metabolite flow, enzymatic activity in root-stem-leaf-fruit system and the accumulation of main quality (sugar) of group is also investigated. Based on above systematic analysis of the regulation mechanism in soil and plant, the physiological mechanism of W-M-C-Q (the relationship among irrigation control, rhizosphere microbial activity, soil carbon source and grape carbon metabolism and quality accumulation in different stages) is formed. The results of this project can provide scientific evidence for quality control of delay-cultured grape in cold region of China and soil biological environment improvement, and also can be used for further molecular level studies to some hot problems, such as quality control and water saving for fruit trees, and soil environmental improvement.

针对我国冷凉地区延迟栽培葡萄灌水粗放、品质不佳及土壤微生物环境恶化问题，利用 PCR扩增和Biolog 微孔板技术，研究水分调控对葡萄根际土壤微生物活性及土壤碳源代谢能力的影响机制。在此基础上，从植物整体碳代谢角度，研究水分调控对根-茎-叶-果实之间碳代谢产物“流”的大小、分布规律、相关酶活性、果实主要品质（糖分）积累的影响机制。通过上述土壤与植物两大调控机制的系统分析，形成具有生理学基础的设施延迟培葡萄水分调控土壤碳源代谢及果实品质协同作用的“W-M-C-Q”（水分调控-根际土壤微生物活性-土壤碳源及葡萄树碳素代谢-主要品质形成过程）生理机制。本研究形成的成果可为我国冷凉地区延迟栽培葡萄品质调控及土壤微生物环境的改善提供依据，也可进一步为从分子水平上研究其它果树节水调质、土壤环境改良等热点问题积累经验。

针对设施延迟栽培葡萄灌水粗放、品质不佳及土壤微生物环境恶化问题，开展水分调控对葡萄根际土壤微生物活性、土壤碳源代谢和果实主要品质（糖分）积累及相关酶活性的影响研究，揭示水分调控对葡萄土壤碳源代谢及果实品质协同作用机制。.研究结果表明：（1）厚壁菌是设施葡萄根际土壤中对水分调控非常敏感的优势细菌门，梭菌是厚壁菌门中水分敏感性优势细菌目；短期水分胁迫可以提高土壤细菌群落丰度。（2）土壤淀粉酶、蔗糖酶活性和微生物量碳对水分胁迫响应敏感，在葡萄生育前期轻度水分胁迫能显著提高土壤淀粉酶活性；短期重度水分胁迫复水后对土壤酶活性和微生物量碳具有补偿效应。（3）全生育期轻度、中度水分胁迫有利于促进设施葡萄土壤微生物对单糖、糖苷、聚合糖类、氨基酸类、醇类、酸类碳源利用程度，提高土壤微生物利用碳源多样性和碳源代谢能力。（4）蔗糖合成酶(SS)是影响葡萄蔗糖积累的关键酶，酸性转化酶(AI)是调节葡萄糖的关键酶，中性转化酶(NI)是调节果糖、葡萄糖以及总糖的关键酶，短期轻度水分胁迫可提高葡萄三种酶活性，但长时段重度水分胁迫抑制果实中AI和NI活性。（5）土壤微生物量碳在葡萄碳代谢及果实糖分积累中发挥重要纽带作用，适度水分胁迫可提高土壤微生物量碳、碳源代谢能力、土壤淀粉酶和葡萄果实中AI活性，促进蔗糖向葡萄糖的转化，进而提高果实中葡萄糖的含量；同时较高的土壤微生物量碳及碳源利用水平可提高葡萄果实中SS活性、NI活性和蔗糖含量，并驱动蔗糖向葡萄糖和果糖的转化和积累，进而促进葡萄果实中总糖的积累，形成了水分调控(W)提高根际土壤微生物活性(M)、土壤碳源及葡萄碳素代谢水平(C)，促进果实糖分积累(Q)的“W-M-C-Q”生理机制。.本研究成果可为我国冷凉地区葡萄延迟栽培品质调控及土壤生物环境的优化提供依据，也可进一步为其它果树节水调质和改善土壤环境等热点问题积累经验。