四倍体苦荞充实差的机理及调控技术研究

Tetraploid tartary buckwheat has such features as growing vigorously, big and good quality of seeds. As well as, it has a good potential of greater production. However, there has been problem for it, like poor grain plumpness. Yet, there are still no many researches on it. Therefore, with 12 high but different grain plumpness tartary buckwheats and their relative tetraploid with low grain plumpness as the experimental material, this paper works on the flowing aspects. First, it gives a dynamic analysis of grain filling for the diploid and tetraploid tartary buckwheat materials. Second, it defines the mechanism for poor grain plumpness of tetraploid tartary buckwheat, by researching on the morphological and physiological root system, the content and type of root exudates, the bleeding intensity in different part, the starch synthesis in grains, the content and proportion of endogenous hormone in different part, and different expressions for protein of the materials during their growth. Third, it conducts a further test and confirmation on the mechanism for poor grain plumpness of tetraploid tartary buckwheat, through different sowing dates, fertilizer management and chemical control and combined with its bleeding intensity in different part, starch synthesis in grains, the content and proportion of endogenous hormone in different part and different expressions for protein. These studies are valuable in further defining the mechanism for poor grain plumpness of tetraploid tartary buckwheat, working out technical methods for improving the grain plumpness of tetraploid tartary buckwheat, and guiding a high-production cultivation of tartary buckwheat.

四倍体苦荞具有生长势强、籽粒大、籽粒品质好等特点，隐含着更高的增产潜力，但是存在充实差等问题，目前相关研究缺乏。本项目以充实度不同的12份苦荞（高充实度）及其对应的四倍体材料（低充实度）为试验对象，主要研究：（1）二倍体和四倍体苦荞材料的灌浆动态分析；（2）通过对供试苦荞材料生长发育过程中根系形态生理、根系分泌物的种类和含量、不同部位伤流强度、籽粒淀粉合成、不同部位内源激素浓度及其比率、蛋白差异表达等方面的研究，明确四倍体苦荞充实差的机理；（3）通过不同播期、肥料管理及化学调控等措施，结合苦荞不同部位伤流强度、籽粒淀粉合成、各器官中内源激素浓度及其比率、蛋白差异表达等的变化，进一步验证四倍体苦荞充实差的机理。通过上述问题的研究，对于进一步明确四倍体苦荞充实差的机理，提出提高四倍体苦荞充实度的技术途径，指导苦荞高产栽培等，均有十分重要的意义。

四倍体苦荞具有生长势强、籽粒大等特点，隐含着更高的增产潜力，然而充实度却比较低，极大的限制了其在生产上的推广利用，针对这一实际问题，本项目系统的研究了荞麦的灌浆特性，探讨了四倍体苦荞充实差的机理，提出了调节四倍体苦荞充实度的调控措施，主要结果如下：. （1）明确了荞麦的灌浆特性。用Richards方程模型拟合了荞麦灌浆过程并对荞麦的灌浆期进行了划分；荞麦不同部位籽粒灌浆进程均呈“慢-快-慢”的生长规律，呈“S”型曲线增长；各灌浆时期对粒重的贡献率均表现为中期＞后期＞前期；高产荞麦品种需在灌浆中后期提高灌浆速率，低产荞麦品种需在灌浆前中期提高灌浆速率才能提高粒重。. （2）明确了四倍体苦荞充实差的机理。用Richards方程对四倍体苦荞的灌浆特性进行分析，发现在花后25天后百粒重几乎不再增加，实际最终百粒重在A±0.008-0.075之间波动；四倍体苦荞的灌浆起始势低于二倍体，达最大生长速率的天数和灌浆速率为最大时的生长量高于二倍体，这些导致四倍体苦荞的充实度较低。另外通过对根系伤流液强度、根系氧化力、根冠比、根系形态等的研究发现，四倍体苦荞充实度差还可能与其在苗期和开花期根系相对弱小、活力低，导致在灌浆期植株营养需求难以满足有关。. （3）提出了播期、肥料和化学调控等措施对四倍体苦荞充实度和产量的调节作用。适宜的播期（8月28日）能明显提高四倍体苦荞的充实度和产量。适宜的氮磷钾肥处理能改善四倍体苦荞根系结构，增加根系长度、表面积和体积等，增加伤流液强度，提高籽粒充实度和产量；有机无机肥复合处理对四倍体苦荞充实度和产量的提高效果最明显。适宜的外源激素组合处理（GA3 75mg•L-1, PPP333 150 mg•L-1, NAA75 mg•L-1）能提高充实度和产量。. 上述研究结果对于明确四倍体苦荞充实差的机理，指导荞麦高产栽培等具有重要的科学和实践意义。. 本项目发表论文13篇，其中SCI收录2篇；申请国家发明专利3件，授权实用新型专利2件；培养硕士研究生4名；获2017年贵州省科学技术进步奖二等奖1项。