Sorghum grown in semi-arid regions is often exposed to stresses during reproductive development, leading to decreased grain yield. In field studies using irrigation, here we (1) evaluated 45 sorghum genotypes in a randomized complete block design with three replications for 3 years for tolerance to high temperature (HT) and resistance to Fusarium stalk and charcoal rots, (2) identified traits conferring tolerance to HT and resistance to two stalk rot diseases, and (3) studied the relationship between Fusarium stalk and charcoal rots with HT. The fungi Fusarium thapsinum and Macrophomina phaseolina were injected into stalks during anthesis. Relative chlorophyll content, photosystem II quantum yield (F_v/F_m), leaf temperature, lesion length, and grain yield were measured. Year had a significant effect on plant height, chlorophyll, F_v/F_m, leaf temperature, lesion length, and seed yield. HT stress decreased chlorophyll and F_v/F_m. For inoculated plants, physiological traits were not related to lesion length or seed yield. However, the chlorophyll index had a significant, negative correlation with leaf temperature. Genotypes PI533946, IS23992, IS26749, SC35, and RTx7000 had the maximum F_v/F_m. Inoculated plants and controls differed significantly in lesion length and seed yield. Genotypes SC35, IS27912, IS19262, and PI576380 had resistance to both pathogens. Principal component analysis indicated that there was no relationship between chlorophyll, F_v/F_m, and leaf temperature with lesion length or seed yield.

中文翻译：

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高温下田间高粱基因型的抗茎腐性和生理特性的变化

在半干旱地区生长的高粱通常在生殖发育过程中承受压力，导致谷物减产。在使用灌溉的田间研究中，我们（1）在随机完整区组设计中评估了45个高粱基因型，并进行了3次重复试验，连续3年，以耐受高温（HT）以及对镰刀柄和木炭腐烂的抵抗力，（2）确定了赋予的性状对HT的耐受性和对两种茎腐病的抵抗力，以及（3）研究了镰刀菌茎与HT引起的木炭腐烂之间的关系。真菌镰刀thapsinum和Macrophomina phaseolina开花期间注入秸秆。相对叶绿素含量，光系统II量子产率（F _v / F _m），叶片温度，病灶长度和籽粒产量均已测量。一年对植物高度，叶绿素，F _v / F _m，叶温度，病斑长度和种子产量有显着影响。高温胁迫降低了叶绿素和F _v / F _m。对于接种的植物，生理特性与病灶长度或种子产量无关。但是，叶绿素指数与叶片温度呈显着负相关。基因型PI533946，IS23992，IS26749，SC35和RTx7000具有最大的F _v / F _m。接种的植物和对照的病灶长度和种子产量差异显着。基因型SC35，IS27912，IS19262和PI576380对两种病原体均具有抗性。主成分分析表明，叶绿素，F _v / F _m和叶温与病灶长度或种子产量之间没有关系。