小麦条锈菌ZS有性与无性菌系毒性差异初步分析

小麦条锈病是小麦生产上最主要的病害,条锈菌毒性不断变异是造成小麦条锈病频繁发生和小麦品种抗病性丧失的主要原因。对小麦条锈菌新菌系开展品种抗病性评价,并探明条锈菌有性菌系、无性菌系间的毒性差异,为科学、超前指导小麦抗病育种和抗病品种的合理布局应用提供技术支撑。2017 — 2021年从454个小麦条锈菌有性菌系和1 728个无性菌系中,获得ZS有性菌系35个和无性菌系167个,占比分别为7.71%和9.66%;其中已归类ZS-1、ZS-18、ZS-52类型中有有性菌系14个、无性菌系72个,占比分别为3.08%和4.17%。2022年选择ZS有性与无性菌系重要类型混合菌,对76个甘肃省内小麦生产品种进行苗期、成株期接种鉴定,结果发现,有性ZS菌系与无性ZS菌系对供试小麦品种苗期致病力分别为97.37%、92.11%,相对寄生适合度分别为0.353 0、0.248 7;成株期致病力分别为 72.37%、71.05%,相对寄生适合度分别为0.362 7、0.184 0。表明有性菌系致病性和寄生适合度均高于无性菌系。建议在陇南越夏区,及早调整小麦抗病育种目标,以持续控制条锈病的发生流行,保障粮食安全。

Analysis of Virulent Difference of Sexual and Asexual ZS type of Puccinia striiformis f.sp. tritici

Wheat stripe rust is a major disease in wheat production, the continuous variation of stripe rust virulence is the main reason for the frequent occurrence of wheat stripe rust and the loss of resistance in wheat varieties. Analysis of virulent difference of sexual and asexual types of Puccinia striiformis f.sp. tritici is the foundation of disease-resistance breeding in wheat. 454 sexual isolates and 1 728 asexual isolates of Puccinia striiformis f.sp. tritici(Pst) were collected during 2017 to 2021. 35 single sexual isolates and 167 asexual isolates were obtained of ZS Pst, which accounted for 7.71% of sexual isolates and 9.66% of asexual isolates, respectively. The major known types included ZS-1, ZS-18 and ZS-52 with 14 sexual isolates and 72 asexual isolates included, which accounted for 3.08% of sexual isolates and 4.17% of asexual isolates, respectively. In 2022, inoculation of typical sexual isolates and asexual mixed isolates of ZS Pst to 76 commercial wheat varieties of Gansu Province at seedling and adult stages was conducted. The results showed that the pathogenicity was 97.37% and 92.11% at seedling stage, and was 72.37% and 71.05% at adult stage for sexual isolates and asexual isolates of ZS Pst, respectively. The relative parasitic fitness was 0.353 0 and 0.248 7 at seedling stage, and was 0.362 7 and 0.184 0 at adult stage for sexual isolates and asexual isolates of ZS Pst, respectively. The value of pathogenicity and relative parasitic fitness of sexual isolates of ZS were higher than those in asexual isolates of ZS. Therefore, adjusting the target in wheat breeding in Longnan over-summering area of Pst ought to be encouraged to ensure the safety of wheat production in Gansu and China in the future.