重庆市核桃炭疽病的病原鉴定及化学药剂筛选

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中图分类号：S433 文献标识码：A文章编号：2097-1354（2025）06-0022-10

Abstract： Walnut anthracnose， caused by Colletotrichum species， poses a severe threat to walnut production in Chongqing，China. It has occurred frequently in recent years， causing symptoms of leaf necrosis，fruit rot and branch cankers，and resulted serious economic losses. To identify dominant pathogens and screen effective fungicides，95 trains were isolated from 93 diseased samples collected from 14 regions of Chongqing. Morphological characterization，molecular identification，and multigene （ITS-ACT-GAPDH-Tub2-CAL） phylogenetic analysis confirmed that the predominant pathogens are Colletotrichum nymphaeae and Colletotrichum gloeosporioides. In vitro toxicity assays with 1O fungicides revealed that carbendazim （benzimidazole） exhibited the highest inhibition effect against C ： gloeosporioides （ ′EC50=0.056μg/mL ）， while boscalid （nicotinamide） showed the highest activity against C . nymphaeae （ EC50=0.015 （20 μg/mL ） and the targeted drug screening strategy was proposed，which provided a scientific basis for the precise prevention and control of regional diseases and drug resistance management. The results of study revealed that walnut anthracnose in Chongqing is primarily caused by the combined infection of C . nymphaeae and C . gloeosporioides. A targeted fungicide selection strategy was proposed， providing a scientific basis for precise regional disease management and resistance governance.

Key words： Juglans regia ; anthracnose; pathogen identification; Colletotrichum nym phaeae ; Colletotrichum gloeosporioides ； fungicide screening

核桃（Juglans regia L.）是胡桃科（Juglandaceae DC.ex Perleb）胡桃属（Juglans L.）多年生落叶乔木，是我国重要的“木本粮油"树种，兼具生态保护和经济价值，其栽培历史可追溯至7000 年前[1]。（剩余8750字）