濒危植物中甸刺玫种子休眠及其生态学意义

对中甸刺玫Rosa praelucens种子结构及其透水性，赤霉素处理对胚的影响，果壳、种皮、胚乳的粗提物活性进行研究。结果表明：(1) 中甸刺玫外种皮是由多层排列紧密的厚壁细胞组成，内种皮为坚硬致密的栅栏组织；(2) 种皮对种子的吸胀阻碍较大, 未处理的种子吸水率较低，吸水13 d后增加量为18.82%；(3) 果实结籽率为0.69%，多数果实中没有饱满的种子；(4) 赤霉素100 mg·kg-1预处理种子可加快胚的萌发速率；(5) 胚乳、种皮、果壳中存在内源抑制物。中甸刺玫种子的休眠是由其形态和生理特点引起的综合休眠。

Seed Dormancy Mechanism and Its Ecological Significance of Endangered Species Rosa praelucens

Seed structure and its water permeability of Rosa praelucens were studied, and the effects of GA3 treatment on embryo were determined. Meanwhile, the activities of crude extract from shell, testa and endosperm were carried out. The results showed that: (1) The testa of R. praelucens is composed of multiple thick-walled cells, arranging compactly, endopleura is composed of hard and dense palisade tissue. (2) The testa has a greater resistance to seed expansion, and the water absorption rate of untreated seed is low. The increment after water absorption 13 d is 18.82%. (3) The average seed setting rate of fruit is 0.69%, and there are no full seeds in most fruits. (4) Pretreatment with 100 mg·kg-1 GA3 can accelerate the germination rate of embryo; (5) Endogenous inhibitors are found in shell, testa and endosperm. The seed dormancy of R. praelucens is a combinational dormancy caused by its morphological and physiological characteristics.