番茄果腐病拮抗菌的筛选及对番茄的防腐保鲜作用

Screening of Antagonist Against Tomato Fruit Rot and Their Preservation Qualities on Tomato

从储藏期间番茄果实中分离到1株果腐病病原菌,为明确其分类地位,寻找合适的生防菌菌株,对其进行形态鉴定和系统发育分析,同时进行了拮抗链霉菌的筛选、鉴定和防腐保鲜作用研究。结果表明,导致番茄采后果腐病的病原菌Qyg16-2为葡萄座腔菌(Botryosphaeria dothidea);从番茄健康植株根际土壤筛选获得对Qyg16-2有良好拮抗作用的放线菌X13,经形态学、生理生化特征及16S rDNA序列鉴定为桑氏链霉菌(Streptomyces sampsonii)。X13能抑制病原菌孢子萌发和菌丝生长,显著提高番茄抗性酶多酚氧化酶(PPO)、过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性,降低储藏番茄的腐烂指数,延缓果实硬度、可溶性固形物、可滴定酸及VC的降低。桑氏链霉菌(S.sampsonii)X13对病原菌葡萄座腔菌(B.dothidea)抑菌效果显著,对储藏番茄具有良好的防腐保鲜作用。

A strain of fruit rot pathogen was isolated from storing tomatoes.In order to clarify the taxonomic status and investigate the suitable biocontrol strain,its morphology and phylogenetic analysis were conducted.The antagonistic Streptomyces was isolated and identified,and its effect on the preservation of tomato was studied.The results showed that the pathogen Qyg16-2 that caused the fruit rot of tomato was Botryosphaeria dothidea.The actinomecetes X13 with good antagonistic effects from healthy tomato rhizospheric soil on Qyg16-2 was identified as Streptomyces sampsonii by morphology,physiological and biochemical characteristics and 16S rDNA sequence.X13 significantly inhibited the colony extension and spore germination of pathogen B.dothidea,its cell-free fermentation filtrate significantly increased the activity of PPO,POD and PAL,decreased the decay index of stored tomato,and delayed the decline of post-harvest tomato fruit firmness,soluble solid content,titration acid content and vitamin C content.Conclusively,S.sampsonii X13 has significant antagonistic effects on B.dothidea,and has promising preservation effect in storing tomato fruit.