外源一氧化氮对苹果采后黑斑病的控制

在离体条件下研究了NO供体硝普钠(sodium nitroprusside,SNP)对苹果黑斑病菌互隔交链孢(Alternaria alternata)生长、菌落形态及其超微结构的影响,并在体内条件下研究了其对苹果黑斑病的治愈作用。结果表明SNP处理能显著的抑制A.alternata的孢子萌发和菌丝生长,存在浓度依赖效应,当浓度为1 g/100 m L SNP,与对照相比,其对菌丝生长和孢子萌发的抑制率分别达到70%和75.9%;扫描电镜和透射电镜观察发现SNP处理的A.alternata菌丝表面粗糙,粗细不均匀,部分出现塌陷;孢子细胞受到不同程度的破坏,细胞膜发生破裂。同时发现外源SNP处理对损伤接种的苹果黑斑病具有治愈作用,其中0.5 g/100 m L SNP处理效果最佳。可见外源NO作为代替化学合成药物的防腐剂在采后病害控制中具有潜在的应用前景。 

Control over exogenous NO on black spot of apple

Effect of nitric oxide(NO) donor sodium nitroprusside(SNP) on the growth,colonial morphology and microstructure of Alternaria alternata were studied in vitro,and its curative and preventative effect for apple black spot control were also evaluated. The results showed that SNP could significantly inhibit spore germination and mycelia growth of A. alternata and the effect was in dose dependent manner. The inhibitory ratios of spore germination and mycelia growth reached to 70%,and 75.9% respectively when treated with 1 g/100 m L SNP.Rough surfaces,uniform thickness,distorted cell and ruptured cell membrane were observed after treatment with SNP by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Meanwhile,SNP treatment not only could cure the black rot on inoculated apple,but also induce the increase of fruit resistance to prevent disease developmemt,the optimum inhibitory concentration was 0.5 g/100 m L SNP. Results suggested that NO,as a safe preservative alternative to synthesis fungicide,might have potential application for postharvest disease control.