西甜瓜蔓枯病菌致病力测定与品种抗病性分析

【目的】研究不同西、甜瓜蔓枯病菌株的致病力差异和不同西、甜瓜品种的抗病性，为指导广西西、甜瓜生产提供科学依据。【方法】采用离体叶片接种法对104个西、甜瓜蔓枯病菌株进行致病力差异分析，并对14个西、甜瓜品种进行抗病性测定。【结果】不同蔓枯病菌菌株致病力存在差异，104个菌株中强致病力菌株、中等致病力菌株和弱致病力菌株分别占31.73%、57.69%和10.58%。不同西、甜瓜品种对同一蔓枯病菌菌株的感病性也存在差异，强致病力菌株WTMK-76对不同西、甜瓜品种病情指数为38.14~86.92，中致病力菌株BHMK-59对不同西、甜瓜品种病情指数为26.88~76.40。10个西瓜品种中以绿美人的抗病性最强，黑美人次之；4个甜瓜品种中以广蜜1号的抗病性最强。【结论】不同的蔓枯病菌菌株致病力存在差异，但菌株致病力强弱与菌株分布的地理位置无关；不同西、甜瓜品种抗病力也存在差异，其中以绿美人、黑美人和广蜜1号的抗病性最强，这3个西、甜瓜品种可在广西推广种植。

Determination on virulence of stem blight (Didymella bryoniae) strains to watermelon and melon and their resistance analysi

【Objective】The present study was conducted to discover the differences in virulence of different  Didymella bryoniae strains to watermelon and melon and their resistance to stem blight in order to provide references on watermelon and melon productions. 【Method】Detached leaves inoculation were used as test materials to study the virulence of 104 strains of Didymella bryoniae to watermelon and melon， and the disease resistance of 14 watermelon and melon varieties was determined. 【Result】Different Didymella bryoniae strains had different virulence to the same watermelon and melon variety. The strong， moderate， and weak virulence strains accounted for 31.73， 57.69， and 10.58% out of the 104 strains of Didymella bryoniae， respectively. Different watermelon and melon varieties produced obviously different disease resistance to the same strain. The disease indexes of strong virulence strain WTMK-76 ranged from 38.14 to 86.92， while that of moderate virulence strain BHMK-59 were 26.88-76.40. Amongst the 10 watermelon varieties， Lümeiren presented the strongest resistance， followed by Heimeiren; and amongst the 4 melon varieties， Guangmi 1 showed the strongest resistance. 【Conclusion】Different Didymella bryoniae strains produce different virulences to watermelon and melon varieties， and there were no correlations between the strain virulence with geographical origin. The resistance of different watermelon and melon varieties were also different trom Didymella bryoniae. Exhibiting the strongest resistance， Lümeiren， Heimeiren， and Guangmi 1 could be widely introduced and planted in Guangxi.