不同品系油茶钾素营养响应差异及其生理机制研究

Camellia oleifera Abel is a unique edible oil woody plant in the southern of China, and the intensive and efficient nutrient management is necessary for getting high yield. Potassium is a quality elements, it affect the yield and quality of C. oleifera Abel, but it is lack in the soil of C. oleifera Abel forestry. At present, there are many different cultivars C. oleifera Abel strains, the research on the differences of their potassium nutritional efficiency was not enough.In this project, the test strains will be selected from current cultivars C. oleifera Abel. Base on soil and recipe testing, combined with sand culture testing, the amount of potassium needed for normal growth and deficit threshold of C. oleifera Abel will be determined, and the nutrient status of soil will be evaluated scientificly.Experimental treatments of potassium levels will be set base on deficit threshold and nutrient status.The differences of potassium growth and physiological effects of C. oleifera Abel will be focused on by analysing plant growth and biomass dynamic, photosynthetic efficiency and physiological substance.The law of distribution and use of potassium in the body will be analysed.In order to reveal the differences of potassium nutrient absorption of strains in physiological level, the root architecture, rhizosphere environment, root activity ,K+ absorption dynamic and kinetic parameters of root will be measured and analyzed.The another aim is to find out the morphological and physiological indicators that can indicates the potassium utilization with Principal Component Analysis.The research results will provide scientific evidences for the precise nutrient management, and establish theoretical basis for the selective breeding of excellent strains that resistant hypokalemia of C. oleifera Abel strains. It will have very significant positive effects in promoting C. oleifera Abel to increase efficiency,, reducing the waste of resources and the environmental pollution.

油茶是我国南方重点发展的木本食用油料树种，实现油茶高产必须进行集约高效养分管理，南方红壤区钾素极度缺乏，严重影响油茶生长与结实，而目前主栽油茶品系有多种，油茶品系的钾素营养效率差异缺乏研究。本项目以当前主栽的油茶优良品系为试材，在测土配方试验基础上，结合砂培试验，确定油茶正常生长需钾量及亏缺阈值，科学评价土壤养分状况，并针对钾素水平设置试验处理；通过植株生长动态及生物量分析、光合效率及生理物质分析，深入研究不同品系油茶的钾素生长和生理效应差异，分析钾素在树体中的分配和利用规律；分析根系构型和根际环境，测定根系活力及根系对K+吸收动态和动力学参数，从生理学层面揭示各品系对钾素营养吸收差异；通过主成分分析，寻找表征油茶钾素营养效率的形态和生理指标。研究结果可为耐低钾优良油茶品系的选育奠定理论基础，为油茶精准养分管理提供科学依据，对促进我国油茶增产增效、节约资源、减轻污染都具有非常重要的意义。

油茶是我国重点发展的木本食用油料树种，主栽品系众多，不同品系钾素营养效率差异缺乏研究。本项目以当前主栽的油茶品系为试材，分别于苗期、幼龄期、成熟龄期开展钾水平试验，通过测定和分析植株生长、生理、结实相关指标，研究了不同品系油茶钾素生长、生理效应差异及其响应机制。结果表明，无论在哪一生长阶段，不同品系油茶的生长速度、生物量积累、光合水分生理、抗性生理、养分吸收和利用、根系形态等均存在不同程度的差异，且这种差异的大小与所处的钾素水平条件有关；不同品系对钾水平的响应不同，有的品系施钾后表现更差，有的以K1水平更好，有的对则钾水平不敏感；因此，在油茶的养分管理中需要虑品系的养分需求差异。整体而言，根中钾养分含量高有利于树体生长，茎中养分含量高对生长和生物量积累不利；长势较好的油茶，夏季高温时产生的抗氧化保护物质较少，形成的渗透调节物质较多，冬季则相反。不同林龄的油茶对钾水平的响应规律及机制存在一些差异。对于成龄期油茶，适量施钾整体可促进地径和叶面积生长，提高果实产量和含油率；施钾没有从光合生理上影响生长与结实，而叶面积的增大能提高蒸腾速率，从而增加果实产量，但同时降低了种仁含油率；施钾促进了细根生长和抽稍期的茎、花、幼果中钾含量的增加，利于果实油脂转化。对于幼龄期油茶，根系是影响叶片生长和生物量积累最主要的因素，施钾促进了侧根极小细根生长、增强根系活力并进一步影响着地上部分的生长。对于苗期油茶，根表面积、根体积、茎中磷含量是直接或间接影响其生长和生物量主要因素，施钾使根表面积和根体积增大，促进植株生长。这些研究结果可为油茶良种选育奠定了理论基础，为油茶精准养分管理提供了科学依据，对促进我国油茶增产增效、节约资源、减轻污染都具有非常重要的意义。