几种板栗品种对链格孢菌的室内抗性比较及防治药剂筛选

Comparison of Resistance of Several Chestnut Varieties to Alternaria alternata and Fungicide Screening in Laboratory

为明确不同板栗品种对链格孢菌(Alternaria alternata)的抗性并筛选出抑制该病原菌的有效药剂,采用离体菌丝块有伤接种法对14个板栗品种进行抗病性鉴定,通过发病率、病斑平均直径法和系统聚类分析法对不同品种进行抗性分级,并利用菌丝生长速率法测定7种杀菌剂对A.alternata的毒力。结果表明,接种后9 d,板栗品种‘燕山短枝’‘大板红’的发病率和病斑扩展直径分别为44.45%、51.11%和0.13、0.20 cm;‘遵玉’为100%和0.90 cm。供试品种中以‘燕山短枝’‘大板红’对A.alternata的抗性相对较强;‘遵玉’对A.alternata的抗性相对较弱。药剂筛选结果表明,咯菌腈对A.alternata的抑制效果最佳,抑制率达到93.75%,EC50为69.94 mg•L^(-1)。以上结果为板栗在种植中筛选优质抗病品种及开展田间药效试验提供参考。

In order to clarify the resistance of different chestnut varieties to Alternaria alternata and screen out effective fungicides to inhibit the pathogen,the resistances of 14 chestnut varieties to A.alternata were identified by in vitro inoculation method.The resistance of different varieties was graded by incidence rate,average diameter of lesion and cluster analysis.The toxicities of 7 fungicides to A.alternata were determined by mycelium growth rate method.The results showed that the incidences and lesion diameters of‘Yanshanduanzhi’and‘Dabanhong’were 44.45%,51.11%and 0.13,0.20 cm after inoculation 9 d,respectively,while those of‘Zunyu’were 100%and 0.90 cm.Among the tested varieties,‘Yanshanduanzhi’and‘Dabanhong’had relatively strong resistance to A.alternata,while‘Zunyu’had relatively weak resistance to A.alternata.The results of fungicide screening showed that fludioxonil had the best inhibitory effect on A.alternata,which the inhibition rate and EC50 were 93.75%and 69.94 mg·L-1,respectively.Above results provided more references for screening high-quality disease-resistant varieties of chestnut in planting and carrying out field efficacy trials.