南疆的埃及棉、皮马棉、中亚海岛棉棉籽油分蛋白蓄积机理研究

Cotton production in Xinjiang has contributed to approximately 50% of total cotton production in China. Cotton seeds have become the primary source for dietary oil provision. As the sole production region of Sea Island cotton in China, the role of Xijiang is irreplaceable in high quality fiber production. Weakness in the biological study on Sea Island cotton is one of the primary reasons that lead to China becoming the biggest importer and consumer of Sea Island cotton in globe trade and meanwhile posing a great challenge to the development of Sea Island cotton industry. Our team previously found that the Sea Island cotton in South Xinjiang deposited higher proportion of oil than protein in seeds. The average ratio of seed oil to seed protein content in over 300 accessions is 1.26. To uncover the underline mechanism of this phenotype, in this project we will evaluate the genetic variations and relationship of protein and oil content in seeds with the fiber quality in Sea Island cotton accessions that grow in precise cropping system. The seed oil and protein biosynthesis related C and N metabolism in single boll and single seed will also be concerned. The temporal and spatial dynamics of seed protein and oil formation will also be characterized in the development of seed in single cotton plant. The correlation of seed oil and protein deposit with leaf SPAD value will be analysis for different boll. Furthermore a quantitative analysis of the seed protein and oil accumulation with SMTR will be conducted and a mathematic model of cotton seed protein and oil accumulation will be established. The predictive power of the model will be assessed by using fiber quality parameters, SPAD value, and cotton seeds as attributes to predict the seed oil content. The results of this project will provide valuable information for synergic improvement of cotton seed and cotton fiber quality in Sea Island cotton breeding, accession assessment and comprehensive utilization of cotton seeds. Also the production of this project will provide guidelines for high yield and high quality cropping practice in Sea Island cotton growing.

新疆棉花产量已占全国总产的半壁江山，棉籽已上升为第一大食用油来源。南疆作为全国唯一的海岛棉基地，在保证优质纤维供给中的作用将无可替代。海岛棉基础研究的薄弱，是造成我国海岛棉进口量消费量全球第一，产业安全面临严峻挑战的重要原因之一。前期工作发现300份种质棉仁油分为蛋白含量的1.26倍。为探索南疆海岛棉高油低蛋白成因，在精准植棉模式下，开展中外品种资源棉籽油分蛋白含量的遗传变异与改良潜力及与纤维品质关系、单铃单籽油分蛋白蓄积的糖氮代谢、单株油分蛋白形成的时空动态、各铃位油分蛋白含量与叶片SPAD值关系的研究，揭示油分蛋白形成的规律，建立油分蛋白积累的模拟模型，解析油分蛋白积量与SMTR的量化关系，探讨纤维品质参数、SPAD值、棉籽性状作为指示含油率的可行性及高油育种的预见性。研究结果可为海岛棉籽-棉品质的协同改良、品种评价及棉籽综合利用等提供生理生化理论依据，对优质高产栽培也具有指导意义。

南疆是我国唯一的海岛棉基地。研究了中外海岛棉不同品种、不同铃室、不同开花期、不同节位棉子油分蛋白蓄积的静-动态规律及与其他因素的关系。结果表明：3年平均，中国、埃及、美国、乌兹别克、土库曼海岛棉品种棉子油产量为686.5、562.2、571.2、512.3和768.3 kg/ha，蛋白产量为606.5、549.2、512.8、535.5和693.1 kg/ha。101个品种2-4室棉铃油分产量为0.367、0.578和0.652 g/铃，蛋白产量为0.362、0.561和0.621 g/铃。141个品种的棉仁油分/蛋白比、油分指数、蛋白指数的改良潜力指数为24.58%、31.89%和34.39%。棉仁含油量、油分蛋白总含量分别与纤维的SCI、MR、UHML、UI、STR、RD呈显著、极显著正相关（r=0.160*-0.436***，n=172）；与ELO、SF、+b呈显著、极显著负相关；棉仁蛋白含量与10项纤维品质性状间无相关性。来自6个国家的42个品种1-3个开花期发育棉仁油分蓄积量与14-70 DPA呈“S”型曲线增长，用Logistic方程拟合，均达到极显著水平；20个品种8个开花期成熟棉子的12个性状与其平均值之间呈显著、极显著正相关。零式株型海岛棉品种不同节位棉仁、棉子油分蓄积过程呈现出随铃位升高而减小、随生育期的延续而增大的时空动态变化特征；4年测定的43个零式果枝品种和60个长果枝品种2301个节位铃棉仁含油率纵向和横向基本维持不变。3年219个品种的棉仁油分含量与叶片SPAD值间、42个品种不同节位棉仁含油量与叶片SPAD值间呈微弱的正相关、负相关、无相关，以SPAD值作为棉子含油量的指示指标还须谨慎。中外53个品种不同节位的棉仁油分、棉酚含量间呈显著正、负相关的有14、2个品种，37个品种不显著，12个品种呈负相关。表明棉仁棉酚含量的多寡并不能左右油分含量的高低，低棉酚海岛棉的培育并不会降低棉仁的含油量。测定101个品种2-4室铃棉朵的纤维可溶性糖含量发现3室铃显著低于4室铃。新疆海岛棉品种资源的棉仁、棉子含油量显著高于埃及棉、皮马棉、中亚海岛棉，在提高新疆海岛棉棉子含油量的遗传改良进程中将其作为首选亲本是适宜的。