徐彦刚　姚协丰　李良俊　徐锦华　任润生　张曼　刘广　娄丽娜　朱凌丽　侯茜　徐建　羊杏平

摘要： 為探究不同西瓜种质资源对蔓枯病的抗性特性，试验通过对80份不同地域来源的西瓜种质资源进行蔓枯病抗性鉴定，并利用SSR标记技术对该材料群体进行基因分型和群体结构分析。结果表明，供试80份材料对亚隔孢壳菌（Stagonosporopsis citrulli）均无免疫性，但不同西瓜品种（品系）间对蔓枯病抗性却存在较大差异，采用欧式距离进行病情指数聚类分析，可将供试西瓜材料依据蔓枯病病情指数分为高抗材料、抗性材料、中抗材料、感病材料和高感材料5组，其中筛选到高抗材料2份，平均病情指数分别为7.13和8.01; 抗性材料19份，平均病情指数23.04～40.10;中抗材料 21份，平均病情指数41.56～57.74; 感病材料24份，平均病情指数59.14～72.33; 高感材料14份，平均病情指数75.03～84.46。基于贝叶斯统计划分的遗传群体构成分析结果可知，4个不同亚群在病级类型和病情指数这2个特性上存在一定差异，其中亚群POP4整体抗病性水平最高，且抗性材料的占比达到33.34%，而亚群POP2抗性材料占比最低。

关键词： 西瓜;蔓枯病;亚隔孢壳菌（Stagonosporopsis citrulli）;抗性评价

中图分类号： S651 文献标识码： A 文章编号： 1000-4440（2021）01-0106-10

Identification and evaluation of the resistance to gummy stem blight caused by Stagonosporopsis citrulli of some watermelon varieties （strains）

XU Yan-gang1，2， YAO Xie-feng1， LI Liang-jun2， XU Jin-hua1， REN Run-sheng1， ZHANG Man1， LIU Guang1， LOU Li-na1， ZHU Ling-li1， HOU Qian1， XU Jian1， YANG Xing-ping1

（1.Institute of Vegetable Crops， Jiangsu Academy of Agricultural Sciences， Nanjing 210014，China;2.College of Horticulture and Plant Protection， Yangzhou University， Yangzhou， 225009，China）

Abstract： To explore the resistant characteristics of different watermelon germplasm resources to gummy stem blight caused by Stagonosporopsis citrulli， 80 watermelon germplasm resources from different regions were used to evaluate their resistance， and simple sequence repeat （SSR） was used to analyze the genotypes and population structure of the samples. The results showed that none of the 80 materials showed immunity to Stagonosporopsis citrulli， but there was difference of the resistance to gummy stem blight between different watermelon varieties （strains）. The testing watermelon materials could be divided into five groups， consisting of highly resistant material， resistant material， medium resistant material， susceptible material and highly susceptible material based on the disease index of gummy stem blight， using Euclidean distance in cluster analysis of disease index. Two highly resistant materials were identified with the average disease index of 7.13 and 8.01 respectively， 19 resistant materials were identified with the average disease index distributed between 23.04 and 40.10， 21 medium resistant materials were identified with the average disease index distributed between 41.56 and 57.74， 24 susceptible materials were identified with the average disease index distributed between 59.14 and 72.33， 14 highly susceptible materials were identified with the average disease index distributed between 75.03 and 84.46. The analysis results of the genetic population structure divided by Bayesian statistics showed that there were some differences in disease level types and disease indices in the four different subgroups. The overall disease resistant level of POP4 subgroup was the highest and resistant materials accounted for 33.34%， but the proportion of resistant materials in POP2 subgroup was the lowest.

Key words： watermelon;gummy stem blight;Stagonosporopsis citrulli;resistance evaluation

西瓜[Citrullus lanatus （Thunb.） Matsum.]是世界上重要的园艺经济作物，其生产规模仅次于葡萄、香蕉、柑橘、苹果，位居第5位[1]。自21世纪以来，中国西瓜产量就一直居世界第一，其中栽培面积达到世界西瓜总面积的60%以上，且产量占据全球西瓜总产量的70%左右[2-3]。近年来随着中国西瓜栽培产区的东移及高效农业的快速发展，设施瓜类栽培已成为中国西瓜生产的重要形式。……