野生茶树雄性不育株细胞学及生理生化特性研究

The wild tea plant germplasms have unique adaptability and genetic diversity, the emergence of male sterile in wild tea plant, it provides an important basic material for the study of genetic variation and heterosis utilization. Study on male sterility of tea plant is not only helpful to understand the biological mechanism of pollen development, but also has important significance in agricultural production practice. In this study, the difference of cytology characteristics and physiological & biochemical properties between male sterile and fertile plant in same species of wild tea plants(Camellia crassicolumna) would be analyzed. First, the floral morphology and field character of male sterile and fertile plants would be investigated by using morphological methods, and the phenotypic characteristics of the male sterility in wild tea plant will be found. Secondly, the meiosis pollen mother cell, anther structure and developmental condition of microspore would be studied on cellular level and the distribution characteristics of fluorescent substances, cytological mechanism of anther abortion of male sterile in tea plant will be elucidated. Last, the contents of endogenous hormones, basal substance metabolism, protein content and antioxidant enzyme activity of male sterile and fertile in wild tea plants would be assayed by using ultraviolet spectrophotometry and HPLC. The relations of the physiological & biochemical characters and the male sterility of wild tea plant will be discussed during different developmental stages. To further reveal the mechanism of anther abortion in tea plant. According to the study of this project, the vital abortion periods of the anther development of male sterile, and the relationship between male sterility and drug wall tissue and physiological and biochemical characteristics in wild tea plant will be elucidated. This project will provide a theoretical basis with breeding, utilization and further study on the mechanism of male sterility in tea plant.

野生茶树资源具有独特的适应性和遗传基因多样性，其雄性不育株的出现为茶树遗传变异研究和杂种优势利用提供了重要的基础材料。研究茶树雄性不育不仅有助于了解茶树花粉发育的生物学机理，而且在农业生产实践中也具有重要的意义。本项目以野生茶树（C. crassicolumna）雄性不育及可育株为材料，拟进行以下研究：从形态学特征入手，调查花器形态和田间性状，明确茶树雄性不育表型特征；从细胞水平及荧光物质的分布特性等方面研究花粉母细胞减数分裂、花药组织结构和小孢子发育情况，阐明茶树花药败育的细胞学机制；测定不同发育时期花蕾中的内源激素含量、物质含量及抗氧化酶活性，动态比较分析生理生化指标差异与茶树雄性不育的关系，从生理生化角度进一步揭示茶树花药败育的机制。通过本项目研究，可望明确茶树雄性不育花药败育发生的时期及其雄性不育与药壁组织和生理生化特性间的关系，为茶树雄性不育系的选育、利用及机理研究提供理论参考。

野生茶树为栽培茶树的野生近缘植物，可采叶制茶饮用。野生茶树雄性不育种质是茶树遗传变异研究和杂种优势利用的重要遗传材料。本项目以国家种质勐海茶树圃保存的野生茶树雄性不育株和可育株花器官为研究材料，从形态学、细胞学与生理生化等层面探讨了野生茶树雄性不育发生的可能机制。植物形态学观察表明，雄性不育株花冠开展度小，花丝弯曲，花药合生粘连、皱缩干瘪、不裂药，花粉粒畸形、无活性、不萌发，染色为典败和圆败。不育株花瓣完整，雌蕊发育良好，花柱长柱型，正常异交结实。野生茶树雄性不育性与花瓣和花柱的发育没有明确关系，但与花药和花丝的发育密切相关，属于雄蕊萎缩型和花药异常型。细胞学观察表明，野生茶树具有2n=30条染色体，不育株花粉母细胞在减数分裂I、减数分裂Ⅱ和四分体时期分别存在环状单价体、滞后染色体、染色体桥、染色体缺失、不均等分离、微核和多分体等多种异常行为，染色体异常频率达38.40%，显著高于可育株。不育株减数分裂期绒毡层细胞异常增生、排列混乱，单核至双核花粉期绒毡层延迟降解；小孢子形状不规则、细胞核散乱模糊，花粉粒凹陷、内含物降解、空包化。野生茶树雄性不育花药和花粉败育主要发生在单核花粉期，绒毡层异常发育和延迟降解，染色体行为异常，小孢子和花粉发育异常可能是其败育的主要原因。生理生化检测表明，花蕾发育中后期不育株可溶性蛋白、可溶性糖和游离脯氨酸含量较可育株偏低，MDA含量较可育株偏高。不育株POD活性呈上升趋势，各发育期均显著高于可育株；不育株SOD和CAT活性呈下降趋势，在单核花粉期和成熟花粉期显著低于可育株；各发育期不育株IAA、ZR和JA含量均显著低于可育株，ABA含量显著高于可育株；ABA/IAA、GA/IAA、ZR/IAA、ABA/GA、ABA/ZR、ABA/JA、JA/GA、JA/ZR和GA/ZR等激素含量比值在不育株与可育株间的变化趋势明显不同，且差异较大。这些生理生化特性变化可能与其雄性不育的发生相关。研究结果为深入认识野生茶树雄性不育机理积累了细胞形态学和生理生化方面的资料，丰富了茶树生殖发育体系研究。本项目已发表研究论文6篇，培育茶树雄性不育系新品种1个，授权发明专利1项，完成了预期研究结果。