小麦对Bipolaris sorokiniana黑胚病与苗期叶枯病抗性的相关性

Correlation Analysis between the Resisitance of Wheat to Black Point and Leaf Blight at Seedling Stage Caused by Bipolaris sorokiniana

为明确小麦抗麦根腐平脐蠕孢(Bipolaris sorokiniana)黑胚病与苗期叶枯病的相关性,以B.sorokiniana为致病菌,采用孢子液喷洒+套袋保湿的方法,于2018-2019年、2019-2020年连续2 a对50份黑胚病抗性不同的小麦品系进行黑胚病与苗期叶枯病的抗性鉴定,分析B.sorokiniana黑胚病发病率(黑胚率)与苗期叶枯病病叶面积占比(病叶面积)的相关性。结果表明,接菌鉴定条件下,50份小麦品系2 a平均黑胚率分别为15.9%与17.4%,2 a均表现抗病的品系有3个[山农5300709、温麦10号、11-253(LWX)],占供试品系的6.0%;黑胚率与叶枯病病叶面积占比呈显著负相关关系(P<0.01),相关系数为-0.914~-0.845;以相关系数最高的2020年叶枯病病叶面积占比与黑胚率进行回归分析(y=-0.585x+48.444,x、y分别为病叶面积占比、黑胚率),预测50个小麦品系的黑胚病抗性,预测结果与接菌鉴定的抗性一致率为90.0%。因此,可用苗期B.sorokiniana引起的叶枯病病叶面积占比预测小麦的黑胚率,为小麦育种中抗黑胚病小麦品系快速鉴定方法的建立提供依据。

To understand the relationship between the resistance to black point and leaf blight caused by Bipolaris sorokiniana in wheat,the correlation between black point incidence and the percentage of diseased leaf area under artificial inoculation with B.sorokiniana at seedling stage was analyzed based on the identification results of 50 wheat cultivars(lines)with different black point resistance,using the method of spraying spore suspension and bagging for moisture for two consecutive years in 2018-2019 and 2019-2020.The results showed that the average black point incidences were 15.9% and 17.4%in 2019 and 2020,respectively,under inoculation condition with B.sorokiniana,and only three germplasms[(SN5300709),Wenmai 10 and 11‑253(LWX)]showed resistance in both years,accounting for 6.0%of the cultivars(lines)tested.There was a significant negative correlation between black point incidence and the percentage of diseased leaf area(P<0.01),with the correlation coefficients ranging from-0.914 to-0.845.The concordance between resistance identification of 50 wheat cultivars(lines)under artificial inoculation with B.sorokiniana and speculation result was 90.0%,according to the regression equation(y=-0.585x+48.444,x and y represented percentage of diseased leaf area and black point incidence,respectively)between black point incidence and the percentage of diseased leaf area with the highest correlation coefficient in 2020.It suggests that black point incidence caused by B.sorokiniana could be predicted by the percentage of diseased leaf area of leaf blight at seedling stage,which provides a basis for the establishment of a rapid identification method of cultivars(lines)with black point resistance in wheat breeding.