光合产物运输效率对空中甘薯源和库的反馈作用机制研究

The relationship among source, translocation and sink is a part of the hotspots in high yield physiological research of sweetpotato. Currently researchers are mainly focussed on the interaction between source and sink, but lack the research of translocation, while photosynthate translocation is a key bridge between the source and sink. This project is based on overhead-sweetpotato cultivation system of roots function separation with inexpensive and easy operation, which was constructed in former project of National Natural Science Foundation of China, the absorbing roots and storage roots of sweetpotato would be separated in space and function. To reveal the relationship between photosynthate translocation efficiency and yield and its feedback mechanism of that, the research model of the relationship between photosynthate translocation efficiency and yield based on the spatial division of roots function of sweetpotato would be constructed through induced into sink in different translocation distance from photosynthetic source. Then analyze it through the research in biology yield, physiology, biochemistry, photosynthetic characteristics, transcriptome, and gene expression. To prove these results, there is another analysis will be held, which is the research of photosynthetic translocation mode in different vine length varieties, and research the regulation rules among photosynthate synthesis, translocation and accumulation under these modes. After that, a model of vine length type will be concluded and built, which has the best harmony of source-sink relationship and best economize and high-performance for photosynthate transportation.Thus, the question of which kind of vine length type varieties that what we need in sweetpotato cultivation and production solved in theory. It will provide a theoretical support and guidance for the sweetpotato vine length breeding, and provide a theoretical basis for the establishment of ideal plant architecture of sweetpotato.

甘薯"源流库"关系是甘薯高产生理研究的热点之一，目前包括水稻在内的粮食作物都主要集中在"源""库"互作的研究上，缺乏对"流"的研究，而"流"是"源""库"互作的桥梁。本项目拟用上一青年科学基金项目中建立的价廉且易操作的空中甘薯根系功能分离栽培技术体系，使储藏根--吸收根在空间和功能上分离，在距光合"源"不同的运输距离上诱导成"库"，建立光合产物运输距离和效率与产量的关系的模型，在生物学产量、生理生化、光合特征、转录组和相关基因表达等不同层次，从"流"的角度揭示光合产物运输效率与产量的关系以及这种关系对"源""库"的反馈作用机制，并通过不同蔓长类型品种光合运输模式和不同模式下光合产物合成、运输及积累规律的分析进行验证，得出"源""库"最协调、"流"最经济和高效的蔓长模型，从而在理论上阐明甘薯最佳蔓长类型的问题，为甘薯蔓长育种提供理论支撑和指导，同时为建立甘薯理想株型模型提供理论依据。

蔓长是甘薯的重要遗传性状，不同品种的蔓长差异很大，生物量差异也很大，因而产量相当不同蔓长的品种，光合运输效率有着明显的差异。减少植株冗余生长，提高光合运输效率获取高产是重要的途径之一，这需要通过构建甘薯理想蔓长来解决。本项目使用甘薯根系功能分离栽培技术体系，使储藏根--吸收根在空间和功能上分离，在距光合“源”不同的运输距离上诱导成“库”，构建了同一遗传背景下的光合产物运输效率与产量关系模型，通过在生物学产量、光合生理、相关基因表达等不同层次实验证据横向比较分析，初步证明了在同一遗传背景下，光合产物运输储存距离越近，藤蔓冗余生长越少，运输效率越高，因而产量也越高，得到了理想蔓长的理论数据，研究结果直接为甘薯育种和高产栽培提供理论支撑。