番茄早疫病菌抗啶酰菌胺菌株的适合度及生物学特性
Fitness and biological characteristics of Alternaria solani with boscalid resistance

为了评价番茄早疫病菌Alternaria solani对啶酰菌胺的抗性风险,采用菌丝直径法和孢子萌发法探讨番茄早疫病菌抗啶酰菌胺菌株的适合度变化和生物学性状差异。结果表明:番茄早疫病菌对啶酰菌胺的抗性可稳定遗传;与敏感菌株相比,抗性菌株的菌丝生长减慢,产孢量明显增多,病斑直径达8.5 mm以上,致病力显著增强,产毒量也有增加的趋势,但孢子萌发率显著差异;啶酰菌胺对抗性菌株的防效显著下降为64.17%~33.49%;抗性菌株的最适pH范围变宽为5~9;中抗菌株的最适温度(25℃)、最佳碳源(淀粉和乳糖)和氮源(蛋白胨)没发生变化,但高抗和极高抗菌株的最适温度范围变宽为25~30℃,最适碳、氮源发生了变化。其中,高抗菌株的最适碳、氮源分别为乳糖和大豆粉;极高抗菌株的最适碳源为淀粉,最适氮源为玉米粉和蛋白胨。表明番茄早疫病菌对啶酰菌胺产生抗性后,较易存活而形成优势群体,因此需采取一定措施延缓抗性的发展、延长啶酰菌胺的使用期限。
To assess the resistance risk of Alternaria solani to boscalid, the fitness and biological characteristics of boscalid-resistant strains were tested by measuring colony diameter or spore germination. The results showed that the boscalid-resistance of A. solani could be inherited steadily. The mycelial growth of resistant strains declined, but the sporulation increased significantly. The diameters of disease lesion of resistant strains were more than 8.5 mm and their pathogenicity also increased obviously. The toxin production of resistant strains tended to increase, but their spore germinations did not vary apparently. The control efficacy (64.17%-33.49%) of boscalid to resistant strains went down significantly. The range of optimum pH (5-9) for resistant strains became wider. The optimum growth temperature (25℃), the optimum carbon source (starch and lactose) and the optimum nitrogen source (peptone) of moderately resistant strains did not change, but the range of optimum growth temperature (25-30℃) of highly and very highly resistant strains became wider, and the optimum nutrient of them changed. The optimum carbon and nitrogen sources of highly resistant strains were lactose and soybean flour, respectively. The optimum carbon source of very highly resistant strains was starch, and the optimum nitrogen sources were peptone and corn flour. Therefore, the boscalid-resistant strains could survive well in the nature and become the dominant population easily. Thus, more control strategies should be considered to postpone the development of resistance and prolong the use of boscalid.