Fusarium wilt of cotton (Gossypium spp.) is caused by a soil- and seed-borne fungal pathogen Fusarium oxysporum f. sp. vasinfectum (FOV). Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) is a significant threat to cotton production in the United States. The effect of temperature and soil on disease symptoms in cultivars with a range of susceptibility to FOV4 was examined in growth chamber trials. Three upland (G. hirsutum L.) and three pima (G. barbadense L.) cultivars were planted in three types of soils (potting mix and farm soils with and without FOV4 preinfestation) and maintained at four constant temperature regimes (20, 23, 26, and 29 °C). After seedling emergence, each pot was inoculated with conidial suspensions of FOV4 and scored for resistance based on disease incidence (DI), foliar disease severity rating (DSR), and mortality rate (MR) at 7, 14, 21, and 28 d post-inoculation (dpi). The area under the disease progress curve (AUDPC) based on DSR across the four evaluation dpi was also analyzed. Among the six cultivars tested, Pima PHY 841 RF, Pima S-6, and the uplands Acala 1517-08 and FM 2334GLT were the most resistant, whereas upland PHY 725 RF and Pima S-7 were the most susceptible. The genotypic responses to FOV4 were not significantly (P > .05) affected by differences in temperature regime or soil type. Cotton seedlings manifested more severe symptoms and higher mortality when maintained at 23 °C, followed by 20/26 °C and 29 °C in descending order. The mycelial growth rate was greater at 23/26 °C, whereas plants grew slower at 20/23 °C. There were no differences (P > .05) in DI, DSR, MR, and AUDPC between the inoculated farm soil (with no FOV4 preinfestation) and the inoculated FOV4-preinfested farm soil, suggesting the unnecessity of using the latter in artificial inoculations. However, the potting soil produced higher (P < .05) DI and DSR at 7 and 14 dpi but lower (P < .05) AUDPC. This growth chamber study demonstrated that 23 °C produced the highest DI, severity, and plant death, providing an important piece of information for screening cotton for FOV4 resistance in breeding and FOV4 disease management in cotton production.

中文翻译：

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温度在评估棉花对尖孢镰刀菌引起的枯萎病抗性方面的重要性。sp. 血管炎种族 4

棉花枯萎病 ( Gossypium spp.) 是由土壤和种子传播的真菌病原体Fusarium oxysporum f 引起的。sp. 血管炎（FOV）。尖孢镰刀菌f. sp. vasinfectum Race 4 (FOV4) 是美国棉花生产的重大威胁。在生长室试验中检查了温度和土壤对 FOV4 易感性范围的品种的疾病症状的影响。三高地 ( G. hirsutum L.) 和三皮马 ( G. barbadenseL.) 栽培品种被种植在三种类型的土壤中（盆栽混合物和农场土壤，有和没有 FOV4 预侵染）并保持在四种恒温状态（20、23、26 和 29 °C）。幼苗出苗后，每个盆都接种 FOV4 分生孢子悬浮液，并根据发病率 (DI)、叶病严重程度等级 (DSR) 和发病后 7、14、21 和 28 天的死亡率 (MR) 对抗性进行评分。 - 接种 (dpi)。还分析了基于四个评估 dpi 的 DSR 的疾病进展曲线下面积 (AUDPC)。在测试的六个品种中，Pima PHY 841 RF、Pima S-6 和高地 Acala 1517-08 和 FM 2334GLT 的抗性最强，而 upland PHY 725 RF 和 Pima S-7 最易感。对 FOV4 的基因型反应不显着（P > .05) 受温度状况或土壤类型差异的影响。棉花幼苗在维持在23°C时表现出更严重的症状和更高的死亡率，其次是20/26°C和29°C，降序排列。在 23/26 °C 时菌丝体生长速度更快，而在 20/23 °C 时植物生长较慢。接种的农田土壤（没有 FOV4 预侵染）和接种的 FOV4 预侵染的农田土壤之间的 DI、DSR、MR 和 AUDPC没有差异（P  > .05），表明没有必要在人工接种中使用后者。然而，盆栽土在 7 dpi 和 14 dpi 时产生较高 ( P  < .05) DI 和 DSR，但较低 ( P < .05) AUDPC。该生长室研究表明，23 °C 产生最高的 DI、严重程度和植物死亡，为筛选棉花育种中的 FOV4 抗性和棉花生产中的 FOV4 病害管理提供了重要信息。