Macrophomina phaseolina is the causal agent of charcoal rot disease of melons causing significant losses worldwide. Use of resistant cultivars is a desirable method for controlling this disease, but there is no information about the influence of temperature on the resistant behavior found in melon accessions. The purpose of the present study was to assess the effect of temperature on the reaction of six melon accessions selected previously for their resistant response to M. phaseolina. Accessions were inoculated with M. phaseolina isolate CMM-1531 and grown under accurately controlled environmental conditions at different temperature regimes (25, 28, 31, and 34 °C) in a replicated experiment. The increase in temperature increased the severity of symptoms in most genotypes, but this effect was less pronounced in the highly susceptible control, the cultivar ‘Piel de sapo’, and in the most resistant accession, the wild African agrestis Ag-15591Ghana, that remained resistant even at 34 °C. The use of several screening temperatures allowed a better characterization of accessions that behaved similarly as highly resistant at 25 °C (Con-Pat81Ko, Dud-QMPAfg, Can-NYIsr and Ag-C38Nig), but in which resistance breaking was observed with temperature rises. Temperatures of 28 °C and 31 °C were sufficient to make Dud-QMPAfg, Ag-C38Nig and Can-NYIsr moderately resistant, whereas Con-Pat81Ko remained highly resistant. All these genotypes were susceptible at 34 °C, which suggest that are not suitable for hot-climate growing areas. The most promising accession was Ag-15591Ghana, whose resistance was confirmed in two greenhouse experiments under stressful temperatures (>34 °C). The behavior of these sources should be confirmed in naturally infested fields, but the controlled screening methods presented here are essential to characterize new resistance sources and to conduct genetic studies when a high number of plants must be managed under controlled environmental conditions.

菜豆巨噬菌是瓜类木炭腐烂病的病原体，在世界范围内造成重大损失。使用抗性品种是控制这种疾病的理想方法，但是没有关于温度对甜瓜品种抗性行为影响的信息。本研究的目的是评估温度对先前选择的六个甜瓜对菜豆的抗性反应的反应的影响。将部分接种了菜豆分枝杆菌在重复实验中，分离出CMM-1531，并在不同温度范围（25、28、31和34°C）的精确控制的环境条件下生长。温度的升高而增加的大部分基因型症状的严重程度，但这种影响在高感的控制不太明显，该品种“彼尔德SAPO”，并在最能抵抗加入，野生非洲蛞蝓Ag-15591Ghana，即使在34°C时仍具有抗性。使用多个筛选温度可以更好地表征在25°C时表现出高抗性的种质（Con-Pat81Ko，Dud-QMPAfg，Can-NYIsr和Ag-C38Nig），但随着温度升高观察到电阻断裂。28°C和31°C的温度足以使Dud-QMPAfg，Ag-C38Nig和Can-NYIsr具有中等抵抗力，而Con-Pat81Ko仍然具有高度抵抗力。所有这些基因型均在34°C时易感，这表明它们不适合热气候生长地区。最有前途的登录号是Ag-15591Ghana，其抗性在两次温室试验中均在胁迫温度（> 34°C）下得到证实。这些来源的行为应在自然出没的田野中确认，