Analysis of 50 Cucumber Accessions by RAPD Markers

Genetic diversity of 50 cucumber (Cucumis sativus L.) accessions from American, Holland, Japan and China was detected and evaluated using RAPD markers. 25 selected primers produced 215 scorable polymorphic RAPD bands and the ratio of polymorphism is 86.98%. Four main groups of cucumber accessions could be distinguished from UPGMA analysis: Occidental cucumber, South-China cucumber, North-China cucumber and Xishuangbanna cucumber. Our result confirmed that cucumber is a narrow-based germplasm, nevertheless RAPD analysis was stili useful in cucumber genotypic differentiation. More significantly, Xishuangbanna cucumber (Cucumis sativus L. Var Xishuangbannanesis Qi et Yuan), a mutation of cucumber, was clustered together to a special group in the study, which implied its special status in cucumber germplasm.

几种化学诱导物对黄瓜白粉病抗性的诱导作用

在建立简单、有效、准确的叶圆片检测黄瓜白粉病抗性的基础上 ,系统地比较了 7种化学诱导物及其组合对黄瓜白粉病抗性的诱导作用。结果表明 ,草酸、水杨酸、苦参碱、苯基硫脲、复合磷均能显著诱导黄瓜对白粉病的抗性。其诱导效果为草酸 >水杨酸 >苦参碱 >苯基硫脲 >复合磷 ,氯化钾和硫酸锰的诱导效果不明显。当苯基硫脲、苦参碱与硫酸锰、氯化钾和复合磷分别组合时与单一诱导物相比 ,诱导效果明显增强 ;而当水杨酸、草酸与之组合时诱导效果明显减弱 ,这可能与离子间相互作用有关。

西双版纳黄瓜群体遗传多样性的SSR分析

西双版纳黄瓜（Cucumis sativus L.var. xishuangbannanesis Qi et Yuan）是我国特有的黄瓜变种。以20世纪70年代末收集的30份西双版纳黄瓜种质273个样本为研究对象,利用SSR技术从群体水平分析其遗传多样性。273个样本的多态位点百分率、Nei s基因多样性指数（H）和Shannon信息指数（I）分别为92.86%、0.1818和0.2972。比较30份种质的遗传多样性指标,显示种质间遗传变异54.06%,种质内遗传变异45.94%。17号种质的遗传多样性最高（H=0.1376,I=0.2032,多态位点百分率37.21%）。聚类分析结果显示,大多数种质的分组与瓜皮色和瓜肉色基本一致。按不同来源地将种质分为5个群体,其中景洪群体的遗传多样性最高,其多态位点百分率、H值和I值分别为76.19%、0.1562和0.2516。群体间遗传一致度在0.9071～0.9889之间。聚类分析结果显示不同来源地的西双版纳黄瓜在遗传组成上存在差异。群体遗传分化系数和基因流分别为0.2201和1.7718,表明西双版纳黄瓜群体间基因分化不明显,基因交流基本顺畅。