结球甘蓝霜霉病抗性鉴定与遗传分析

Identification and Genetic Analysis of Downy Mildew Resistance in Brassica oleracea var. capitata L.

在经过高代自交选育出结球甘蓝高抗霜霉病自交系R103和感霜霉病自交系S101的基础上,根据苗床田间自然发病的S101病害症状,以及病原物镜检和回接鉴定,明确该病害的病原是十字花科霜霉菌。经过苗期田间自然诱发和十字期人工室内接种抗性鉴定,以感病亲本为回交亲本的BC1群体中抗病株和感病株的比例,田间是0.91∶1,室内为0.96∶1,经卡平方适合性检测均符合1∶1分离比例;F2分离群体中自然鉴定和人工鉴定抗病单株和感病单株的比例分别为2.93∶1和3.01∶1,检测结果经卡平方分析证明均符合3∶1的分离比例,2种抗性鉴定方法都表明这些群体中结球甘蓝霜霉病抗性受单基因显性控制,为了缩短抗性鉴定时间,可采用人工接种鉴定代表整个苗期结球甘蓝霜霉病抗性。

We confirmed that the pathogen of cabbage downy mildew was obligate cruciferae Hyaloperonospora parasitica,according to the symptom of the susceptive S101 in filed,and the result of pathogen microscopical examination and re-inoculating on susceptive materials having no disease.Then did the genetic analysis by natural induction in field and artificial inoculation in greenhouse,the proportions of resistant plants and susceptive plants were 0.91 ∶ 1（in field）and 0.96 ∶ 1（in greenhouse）in the backcross population constructed by F1 crossing susceptive parent S101,as are in accordance with 1 ∶ 1 separation rate assayed by the Chi-square test.In the F2 separation population,the proportions were 2.93 ∶ 1（in field）and 3.01 ∶ 1（in greenhouse）,being in accordance with 3 ∶ 1 separation rate by the same test.Two kinds of resistance identification methods show that the resistance to downy mildew of these population is monogenic inheritance,so we could use the artificial inoculation in cross stage to identify the resistance to cabbage downy mildew in entire seedling stage simply and fastly.