白菜型油菜品种萌发期的抗旱性鉴定与筛选

Identification and Screening of Resources with Tolerance against Drought Stress in Brassica rapa during Germination Stage

秋旱影响我国长江流域油菜的播种和生长。从遗传基础广泛的白菜型油菜资源中筛选抗旱材料,对于培育抗旱油菜品种具有重要意义。以不同浓度的PEG-6000溶液于萌发期对5份不同遗传背景的白菜型油菜进行模拟干旱胁迫处理,并测定种子萌发抗旱指数、相对发芽率、相对发芽势、相对根长、相对芽长。与对照相比,干旱胁迫下各指标均有显著差异,对各指标进行主成分分析,确定了抗旱性鉴定参数,并确立了白菜型油菜资源抗旱性筛选的工作液为200 g/L的PEG-6000。选用该工作液于萌芽期对203份白菜型油菜资源进行了抗旱筛选,结果表明,模拟干旱胁迫下,大部分材料的抗旱性与对照有显著差异,用隶属函数法和聚类分析对抗旱性鉴定指标进行分析,并对所有供试材料的抗旱性进行了排序,鉴定出了抗旱性最强的PI226505白菜型油菜,其来源为Iran,为油菜下一步抗旱性遗传改良奠定了基础。

Drought in autumn has negative effect on germination and growth of ley. It is critical to identify drought tolerance resource in Brassica rapa for rapeseed rapeseed in Yangtze River val- breeding. The drought tolerance among five B. rapa accessions with different genetic background were evaluated using seven treatments concentration of PEG-6000, ranging from 0 to 300 g/L during germination stage. Significant differences were detected for drought tolerance among seven treatments, and optimum concentration of PEG-6000 was 200 g/L based on the principal components analysis for five indexes related to drought tolerance, including drought resistance index, relative germi- nation rate, relative sprout potential, relative root length, and relative shoot length. Subsequently ,203 B. rapa collect- ed worldwide were screened for drought tolerance with 200 g/L PEG-6000. Based on the result of membership func- tion value analysis and cluster analysis, we prioritized all the experimental materials according to the drought stress. Additionally, PI226505 from Iran possessed the strongest drought tolerance,which would be helpful for drought tol- erance improvement in oilseed rape