微咸水灌溉方式对番茄果实糖积累及蔗糖代谢影响机理

To aim at the problems of the scare freshwater resources in northwest regions, and the rich underground brackisk water resources with relatively low utilization, 4-year field experiment was designed to investigate the effect mechanism of brackisk water irrigation modes on tomato fruit sugar accumulation and sucrose metabolism in this project. Using tomato as material, irrigation with brackish water will be used as control, irrigation with purified water, mix irrigation with brackish water and purified water (1: 1), and rotation irrigation with brackish water and purified water according to times and growth stage will be served as treatments, respectively. The synthesis and distribution of photosynthate in the tomato leaves and fruits will be tested using carbon isotope label. Dry mater accumulation, and composition and content of sugar during tomato fruit development in different treatments will be analyzed by HPLC. Transcriptomics will be used to analyze differentially expressed genes associated with fruit sugar accumulation and surcrose metabolism in tomato fruits, to built the network of sucrose metabolism, to excavate transcription factor of key regulators and sugar transporters, and to explore the relationship between these spatio-temporal expression and fruit sugar accumulation and surcrose metabolism. The mineral elements and ion content of soil, leaves and fruits will be analyzed with the aim to explore the correlation of these and fruit sugar accumulation and surcrose metabolism. The successive data will help to understand the continuous effect of brackish irrigation modes on sugar accumulation and sucrose metabolism. Eventually the study will clarify the physiological and molecular mechanisms of the effect of brackish irrigation modes on tomato fruit sugar accumulation and sucrose metabolism, which will provides a theoretical basis for using of brackish water reasonably, developing of high quality tomato production, and promoting tomato industry sustainable development.

针对西北淡水资源匮乏，地下微咸水资源丰富而利用率低问题，以番茄为材料，微咸水直灌为对照，净化水灌溉、微咸水与净化水（1:1）混灌、微咸水与净化水按次和生育期轮灌为处理，通过4年的田间定位试验，利用14C标记光合产物在番茄叶片和果实内的合成与运输分配特性；利用HPLC分析各处理不同发育期番茄果实干物质累积、糖分组成及含量；利用转录组测序分析各处理番茄果实中与糖积累和蔗糖代谢相关的差异表达基因，构建蔗糖代谢网络，发掘关键调控转录因子、糖转运蛋白，探索其时空表达规律与番茄果实糖积累和代谢的关系；分析微咸水介入下的土壤、叶片和果实内的矿质元素和离子含量，探究其与番茄果实糖积累、蔗糖代谢的关联；通过连年数据揭示微咸水灌溉方式对糖累积和蔗糖代谢影响的连年效果，最终阐明微咸水灌溉方式对番茄果实糖积累和蔗糖代谢影响的生理和分子机理，为合理利用微咸水、发展高品质番茄生产，促进番茄产业可持续发展提供理论依据。

针对西北淡水资源匮乏，地下微咸水资源丰富而利用率低问题，以番茄“京番301”为试材，微咸水直灌为对照，净化水灌溉、微咸水与净化水（1:1）混灌、微咸水与净化水按次和生育期轮灌为处理，完成了4年的田间定位试验研究，主要研究内容和结论如下：①通过微咸水灌溉对设施番茄果实糖积累及蔗糖代谢相关酶活性的影响研究，发现微咸水直接灌溉和微咸水淡水按次轮灌可以提高果实各部位葡萄糖、果糖和蔗糖的含量，从而改善番茄果实品质；②通过微咸水灌溉方式对设施番茄根区土壤矿质元素及离子含量的影响研究，发现微咸水、淡水按次轮灌能在一定程度上提高土壤中全量养分和速效养分含量，土壤盐分离子积累最少，为微咸水较为合理、安全的利用方式；③微咸水灌溉方式对不同生育期设施番茄矿质元素含量的影响，发现短期微咸水灌溉或降低微咸水的矿化度灌溉( 轮灌、混合水灌溉) 不仅能够节约淡水资源，而且可以有效避免微咸水直接灌溉对植株生长的不利影响，并补充植物所需的 N、Ca、Mg、Fe、Mn、Cu 等营养元素；④通过微咸水灌溉对日光温室番茄产量及果实各部位蔗糖代谢的影响研究：得出结论：结合番茄产量和土壤盐分、养分积累情况，认为微咸水和淡水按次轮灌为最佳灌溉方式；⑤通过微咸水灌溉方式对光合产物在番茄果实内的分配的影响研究，发现在微咸水灌溉处理中以微咸水、淡水按次轮灌的番茄果实的生物量分配比最高，其次为微咸水、淡水按生育期轮灌。⑥通过微咸水灌溉对番茄成熟期转录组和果实糖含量的影响研究，发现用微咸水与淡水按生育期轮灌会导致对整体基因表达的重新编码，此外，该处理中上调的DEGs加强了信号传导，激素代谢和逆境耐受性，促进了信号传导和植物激素的协调作用。研究最终阐明了微咸水灌溉方式对番茄果实糖积累和蔗糖代谢影响的生理和分子机理，为合理利用微咸水、发展高品质番茄生产，促进番茄产业可持续发展提供理论依据。