生防菌+恶霉灵最优组合的筛选及对苦瓜枯萎病的防治效果研究

Screening of Optimum Combination of Biocontrol Bacteria+Hymexazol and Studies on Its Control Effect on Bitter Gourd Fusarium Wilt

苦瓜枯萎病是由尖孢镰孢菌苦瓜专化型(Fusarium oxysporum f.sp.momordicae)侵染引起的一种土传病害,目前市场上缺乏防治效果较好的农药或生防菌剂。为了更好地防治苦瓜枯萎病,通过盆栽试验筛选出绿针假单胞菌(Pseudomonas chlororaphis)G5与恶霉灵复配施用的最优组合,并在苦瓜枯萎病发病样地对盆栽试验筛选出的最优组合进行防效验证。试验结果表明:菌药组合B+0.75Hym(1×10^9cfu·mL^-1G5菌悬液+187.5mg·L^-1恶霉灵)处理对盆栽苦瓜枯萎病的防病效果为81.60%,明显高于其他处理;同时该组合对苦瓜幼苗的促生作用最为明显。接种苦瓜枯萎病菌后,菌药组合B+0.75Hym的苦瓜叶片中PAL、PPO、POD防御酶活性较高。田间防效验证试验中苦瓜苗移栽30、60d后菌药组合B+0.75Hym对苦瓜枯萎病的防治效果较高,分别达到了52.59%、32.13%,且苦瓜产量也高于其他处理。表明盆栽试验筛选出的菌药最优组合B+0.75Hym不仅能够降低农药的使用量,而且能够有效防治苦瓜枯萎病,提高苦瓜产量,有一定的生产实用价值。

Bitter gourd Fusarium wilt is a soil-borne disease caused by Fusarium oxysporum f. sp. momordicae.At present,better pesticides or biocontrol agents are in urgent need in market.In order to control bitter gourd Fusarium wilt with better effect,this paper conducted pot cultivation experiment,screened the optimal combination of Pseudomonas chlororaphis G5+hymexazol.The control effect of the optimal combination screened by pot experiment was verified in the pathogenic area of bitter gourd Fusarium wilt.The results showed that the combination B+0.75Hym(1×10^9 cfu · mL^-1 G5 suspension+187.5 mg · L^-1 hymexazol)had 81.60% disease control effect on potted bitter gourd Fusarium wilt,which was higher than that by the other treatments.At the same time,the combination had the most obvious growth promoting effect on bitter gourd seedlings.After inoculation with Fusarium oxysporum,the activities of PAL,PPO and POD defense enzymes in bitter gourd leaves treated with combination B+0.75Hym were higher.The control effect in field experiment of combination B+0.75Hym on bitter gourd Fusarium wilt was 52.59% and 32.13%,respectively 30 days and 60 days after transplantation.And the yield of bitter gourd was also higher than that by the other treatments. These results showed that the optimum combination B+0.75Hym screened from pot experiment could not only reduce the application amount of pesticides,but also effectively control bitter gourd Fusarium wilt and increase bitter gourd yield.It has certain practical value in production.