采后葡萄果实营养对灰霉菌致病性的影响

 以采后巨峰葡萄果实（Vitis vinifera L.cv.Kyooho）为试材，从葡萄的营养、pH、贮藏期生理状态以及环境温度对灰霉菌（Botrytis cinerea）生长发育和致病性影响方面进行了研究。结果表明，葡萄果实的营养和pH值适于灰霉菌的菌丝生长和分生孢子萌发。在葡萄营养培养基上灰霉菌与葡萄的其它采后致病菌，如链格孢菌（Alternaria alternata），镰刀菌（Fusarium sp.）、芽枝霉（Cladosporium sp.）和粉红单端孢菌（Trichotecium roseum）相比具有显著的生长优势。在pH 3.46的葡萄果汁上，灰霉菌分生孢子在0～35 ℃的温度范围内都能萌发， 最适萌发温度为15～24 ℃，0 ℃培养48 h后分生孢子仍然有8.7%的萌发率。灰霉菌分生孢子在低温下萌发需要较低的pH条件， 在pH 4的葡萄果汁中，4 ℃培养72 h后萌发率可达90%以上，高于pH 5～7的果汁。葡萄果实贮藏期的生理衰老状态与灰霉菌的侵染力存在着时序关系，即灰霉菌的侵染力随着葡萄果实贮藏期的延长而加强。受灰霉菌侵染后的葡萄果实产生过氧化物酶（POD）和几丁质酶的活性均低于链格孢菌诱导的活性。

Effects of Grape Berry Nutrition on Postharvest Pathogenicity of Botrytis cinerea

The postharvest grape berries (Vitis vinifera L. 'Kyoho') were used to investigate effects of the nutrition, pH and physiological condition of grape，and environmental temperature on the conidia development and the hypha growth of Botrytis cinerea. The results indicated that the nutrition and pH value of the grape extract were very suitable for the conidia germination and hypha growth of B.cinerea. Compared with other postharvest pathogens, such as Alternaria alternata, Fusarium sp., Cladosporium sp. and Trichotecium roseum, B.cinerea had significant growth predominance on the grape extract medium. The spores of B. cinerea germinated between 0～35 ℃ when incubated in the medium of grape juice at pH 3.46. The optimal germination temperature of spores was 15～24 ℃ and the germination rate of B. cinerea spores was 8.7% even cultured at 0 ℃ for 48 h. The germination rate at pH 4 was above 90% when cultured at 4 ℃ for 72 h and was higher than at pH 5-7. This suggests that the spore germination of B.cinerea need low pH at low temperature. The invasiveness of B. cinerea enhanced with the extension of storage. B. cinerea reduced the POD and chitinase activity of the host during the infection process. The results suggest that B.cinerea is more compatible with postharvest grape berries than A.alternata.