黄瓜白粉病菌在不同抗性黄瓜材料上的侵染过程

白粉病是黄瓜生产中发生普遍,危害严重的主要病害之一。pm5.1和PM5.2是黄瓜上的2个白粉病抗性位点,本文对7份不同抗病基因型的黄瓜自交系进行了黄瓜白粉病抗性鉴定,并开展了黄瓜白粉病菌侵染过程的研究,对侵染后12、24、72 h的萌发率、菌丝形成率及菌落形成率等进行了分析。结果表明,当基因型为PM5.1PM5.1 pm5.2pm5.2时,黄瓜病情指数最高,表现为高感白粉病;当基因型为PM5.1PM5.1PM5.2 PM5.2和pm5.1pm5.1pm5.2pm5.2时,表现为中感白粉病;当基因型为pm5.1pm5.1PM5.2PM5.2时黄瓜自交系病情指数最低,表现为抗白粉病。分生孢子在抗、感黄瓜自交系植株叶片上均能萌发,但只能在感病黄瓜材料上完成整个无性生长周期,产生分生孢子。此外,黄瓜白粉病菌分生孢子在感病材料上的萌发率、菌丝形成率及菌落形成率均高于抗病材料。

The infection process of Sphaerotheca fuliginea on different resistant cucumber materials

Powdery mildew caused by the infection of Sphaerotheca fuliginea is one of the severe diseases in cucumber production. pm5.1 and PM5.2 confer the resistance to powdery mildew in cucumber. Here, the resistance to powdery mildew of seven cucumber inbred lines with different disease-resistant genotypes were characterized firstly, and then the infection process of S.fuliginea on these inbred lines were studied in detail. The germination rate, the formation rate of hyphae and the formation rate of colony at different time courses (12, 24, 72 h) after infection were analyzed. The results showed that, when the genotype was PM5.1PM5.1pm5.2pm5.2, the disease index of cucumber was the highest, showing high susceptibility to powdery mildew; when the genotypes were PM5.1PM5.1PM5.2PM5.2 and pm5.1pm5.1pm5.2pm5.2, the resistance improved, showing moderate susceptibility to powdery mildew, and when the genotype was pm5.1pm5.1PM5.2PM5.2, the disease index was the lowest, showing resistance to powdery mildew. Conidia of S.fuliginea could germinate on both resistant and susceptible cucumber materials, but the whole asexual growth cycle could be completed only on susceptible cucumber materials, and conidia could be produced only on susceptible cucumber materials. In addition, the germination rate, hyphal formation rate and colony formation rate of S.fuliginea conidia on susceptible materials were higher than those on resistant materials.