生物源杀菌剂及其与戊唑醇复配对苹果主要炭疽菌的室内活性评价分析

Laboratory activity evaluation of biological fungicides and their combination with tebuconazole to major species from Colletotrichum spp.causing apple bitter rot

苹果免套袋生产已经成为苹果产业转型升级的必然趋势,然而去袋后,主要由胶孢刺盘孢和尖孢刺盘孢侵染引起的苹果炭疽病会引发烂果、落果,严重影响苹果产量和品质,且面临果面农药残留的问题。为此,筛选可用于防控上述病害的生物源杀菌剂至关重要。采用菌丝生长速率法首先测定了8种生物源杀菌剂对2种病菌菌丝生长的抑制效果,结果表明,50亿cfu/g多粘类芽孢杆菌、100亿cfu/g枯草芽孢杆菌、300亿cfu/g解淀粉芽孢杆菌对2种病菌菌丝生长的抑制效果较好,对胶孢刺盘孢的EC_(50)值分别为1.489×10^(-5)、5.911×10^(-1)、1.717×10^(-5)μg/mL,对尖孢刺盘孢的EC_(50)值分别为2.810×10^(-4)、1.302×10^(-1)、1.110×10^(-2)μg/mL。进而分析了上述药剂与常用化学药剂43%戊唑醇的最佳复配比,结果表明,100亿cfu/g枯草芽孢杆菌与43%戊唑醇按1∶1比例复配时,对胶孢刺盘孢的抑制效果最好,增效比为1.093×10;300亿cfu/g解淀粉芽孢杆菌与43%戊唑醇按1∶1比例复配时,对尖孢刺盘孢的抑制效果最好,增效比为1.542×10^(2)。综上,推荐选用50亿cfu/g多粘类芽孢杆菌、100亿cfu/g枯草芽孢杆菌和300亿cfu/g解淀粉芽孢杆菌作为防治苹果炭疽病的生物源杀菌剂,1∶1配比的100亿cfu/g枯草芽孢杆菌与43%戊唑醇以及1∶1配比的300亿cfu/g解淀粉芽孢杆菌与43%戊唑醇对病害防控具有明显的增效作用。该研究对化学农药减施和病害绿色防控提供了重要依据。

Apple bag-free production has become an inevitable trend.However,Colletotrichum gloeosporioides and C.acutatum will cause rotten and falling fruit,seriously affect the yield and quality of apples when the apples are produced without bagging,together with a high risk of pesticide residues on fruit surface.Thus,screening biological fungicides that could be used to control these diseases is critical.In this study,the inhibition effect of 8 biological fungicides on the mycelium growth of C.gloeosporioides and C.acutatum was analyzed,respectively.The results showed that 5 billion cfu/g Bacillus polymyxum,10 billion cfu/g B.subtilis and 30 billion cfu/g B.amyloliquefaciens had the best inhibition effect on the mycelium growth of the two pathogenic fungi.Among them,the EC_(50)values of 5 billion cfu/g B.polymyxum,10 billion cfu/g B.subtilis and 30 billion cfu/g B.amyloliquefaciens to C.gloeosporioides were 1.489×10^(-5),5.911×10^(-1),1.717×10^(-5)μg/mL,respectively;the EC_(50)values to C.acutatum were 2.810×10^(-4),1.302×10^(-1),1.110×10^(-2) μg/mL,respectively.Further,the indoor toxicity was determined by compounding the above-mentioned three biological fungicides with 43%tebuconazole.It was found that when the ratio of 10 billion cfu/g B.subtilis and 43%tebuconazole was 1∶1,the inhibition effect on C.gloeosporioides was the best,and the synergistic ratio was 1.093×10.When the ratio of 30 billion cfu/g B.amyloliquefaciens and 43%tebuconazole was 1∶1,the inhibition effect on C.acutatum was the best,and the synergistic ratio was 1.542×10^(2).In conclusion,5 billion cfu/g B.polymyxum,10 billion cfu/g B.subtilis and 30 billion cfu/g B.amyloliquefaciens are expected to be candidate biological fungicides against C.gloeosporioides and C.acutatum.10 billion cfu/g B.subtilis and 43%tebuconazole in 1∶1 ratio could be used to control C.gloeosporioides,and 30 billion cfu/g B.amyloliquefaciens and 43%tebuconazole in 1∶1 ratio could be used to control C.acutatum.The results provided important basis for chemical fungicide reduction and green disease control.