宁夏枸杞鲜果采后病原菌的分离、鉴定及水杨酸的抑病效果研究

目的 分离、鉴定宁夏中宁地区引起枸杞鲜果采后病害的主要病原菌, 并研究水杨酸(salicylic acid, SA)的抑病效果。方法 采用常规方法从自然发病果实中分离病原真菌, 通过形态学和ITS(internal transcribed spacer)序列信息进行鉴定。使用不同浓度的水杨酸处理病原菌和果实, 观察SA对病原菌体外和体内的抑制效果。结果 共分离到4株病原真菌菌株, 它们均能引起枸杞鲜果的采后腐烂。其中, WB-1鉴定为梨黑斑链格孢(Alternariagaisen), WB-2鉴定为互隔链格孢(Alternariaalternata); WB-3和WB-4分别鉴定为镰刀霉属(Fusarium)和枝孢属(Cladosporium)真菌。SA对3种供试病原真菌的生长均有明显抑制作用, 且SA浓度越高抑制效果越明显。SA浸泡处理对常温和低温贮藏的枸杞鲜果病害有显著的控制效果, 并且SA处理对枸杞果实固形物含量(soluble solids content, SSC)无显著影响。结论 枸杞鲜果采后腐烂由多种病原真菌引起, SA处理对枸杞采后病害具有较好的控制效果, 具有潜在的应用前景。

Isolation and identification of postharvest pathogens in fresh wolfberry from Ningxia and the inhibitory effect of salicylic acid

Objective To isolate and identify the main pathogens causing postharvest decay of fresh wolfberry (Lycium barbarum L) fruits, and study the inhibitory effect of salicylic acid (SA). Methods Fungal pathogens were isolated from decayed wolfberry fruits by routine methods and identified according to morphology and ITS (internal transcribed spacer) sequence information. Different concentrations of salicylic acid were used to treat pathogens and fruits, and the inhibitory effects of SA on pathogens in vitro and in vivo were determined. Results A total of 4 fungal pathogen strains were isolated, all of which could cause postharvest decay in wolfberry fruits. Among them, WB-1 was identified as Alternariagaisen, WB-2 as Alternariaalternata, WB-3 and WB-4 as Fusarium spp. and Cladosporium spp., respectively. SA could inhibit the growth of 3 tested pathogen strains, and the inhibitory effects increased along with the concentration of SA. SA treatment showed significant control effect on postharvest decay in fruits stored at both room temperature and low temperature. Moreover, SA treatment had no significant effect on the soluble solids content (SSC). Conclusion Postharvest decay of fresh wolfberry fruits is caused by a variety of fungal pathogens. SA treatment has a good control effect on postharvest diseases of wolfberry and shows a potential application prospect.