稻曲病菌无性孢子萌发及在不同培养基上生长特性

Characteristics of asexual spore germination and growth of Ustilaginoidea virens in different media

采用不同的培养基研究稻曲病菌孢子萌发及病菌生长特性。结果表明,稻曲病菌厚垣孢子和分生孢子在蒸馏水和2%蔗糖溶液中3h不能萌发;6h时分生孢子、厚垣孢子分别萌发产生次生分生孢子和分生孢子;新采集的黄色和黑色稻曲球上的厚垣孢子在2%蔗糖溶液中的萌发率均高于其在蒸馏水中的萌发率。供试的9种固体培养基中,以马铃薯蔗糖琼脂培养基(PSA)最适于病原菌生长,生长速率为2.54mm/天;病菌在7种培养液中振荡培养7天后,在马铃薯葡萄糖培养液(PDB)中菌丝干重最大,达24.5mg/mL,在大米汁和马铃薯蔗糖培养液(PSB)中产生的分生孢子量最多,孢子浓度分别为2.63×107和2.28×107个/mL;而固、液态的Czapek、稻秆汁和胁本哲氏培养基均不适宜于稻曲病菌的培养。

In order to elucidate the characteristics of asexual spore germination and screen suitable media for pathogen＇ s growth and sporulation, the germination and growth characteristics were studied in different culture media. The results showed that the chlamydospores of the pathogen and conidia was not germinated after 3 h in distilled water or 2% sucrose solution, and primary conidia and chlamydospores could germinate and produce secondary conidia and conidia by 6 h, respectively. Chlamydospores with yellow or black galls have higher germination rate in 2% sucrose solution than that in distilled water. Among the solid culture media tested, PSA （potato sucrose agar） supported fastest mycelial growth at 2.54 mm/d. In liquid culture, dry weight of mycelia was highest in PDB （potato dextrose broth） at 24.5 mg/mL. The number of conidia was the largest in the rice extract medium and PSB medium with 2.63×10^7 spores mL^-1 and 2.28×10^7 sporesmL^-1, respectively. However, both solid and liquid media with Czapek, rice stalk extract and wakimoto toceshi were not suitable for mycelial growth.