沙棘属植物果实大小变异的遗传机制研究

胡颓子科沙棘属的中国沙棘和肋果沙棘，是多年生、雌雄异株落叶灌木或乔木，分布于我国黄土高原和青藏高原，抗旱寒、抗风沙、耐盐碱、可用于水土保持和土壤改良，果实药食同源。沙棘营养丰富，种间果实大小差异显著，是研究果实大小进化发育的良好试材。本项目拟从进化发育生物学的角度出发，开展中国沙棘与肋果沙棘果实发育过程中的细胞学观察、转录组的比较研究、候选基因的筛选及其分子生物学特性分析和功能研究，以及分子进化分析等研究内容，着重对调控沙棘果实大小的关键候选基因进行比较研究。通过研究两种沙棘发育过程中细胞分裂和细胞延伸活动以及基因表达变化的规律，阐明基因表达变化与果实大小之间的联系，初步揭示关键候选基因在不同沙棘中的功能分化、作用机理和演化模式，从而探讨沙棘属植物果实发育调控网络在进化上的保守性与多样性。同时，这一研究为野生沙棘的大规模栽培、有效保护和合理开发利用沙棘资源提供理论基础和技术支持。

Hippophae rhamnoides subsp. sinensis and Hippophae neurocarpa, two species of the genus Hippophae in Elaeagnaceae, are perennial, dioecious and deciduous shrubs or trees, which are mostly distributed in the Loess Plateau and the Qinghai-Tibet Plateau of China, have great environmental adaptation of the high tolerance to drought, cold, wind-blown sand and saline-alkaline, can be used for water and soil conservation as well as soil improvement, and also have medicinal and edible value. Abundant active ingredients are contained in Hippophae, and they are good materials to study the evolution and development of fruit size because there are significant variations in fruit size between species. From the perspective of evolutionary developmental biology, this project intends to carry out cytological observation of H. rhamnoides subsp. sinensis and H. neurocarpa berries at different developmental stages, comparative analysis of transcriptome, target genes screening, molecular biological characteristics analysis and function research of candidate genes, and molecular evolutionary analysis and so on. Among them, we mainly focus on comparatively studying the key genes regulating fruit size of H. rhamnoides subsp. sinensis and H. neurocarpa in detail. By studying cell division and cell extension activities along with the rules of genes expression changes in the development of two kinds of Hippophae berries, we want to illuminate the relationship between the changes of genes expression and fruit size, to reveal preliminarily functional divergence, molecular mechanism and evolutionary pattern of key candidate genes in different Hippophae, and to further investigate evolutionary conservation and diversity of regulatory networks underlying the fruit development in angiosperms. Moreover, this study provides theoretical basis and technical support for the large-scale cultivation, the effective protection and the rational development and utilization of Hippophae resources.