高温对棉花造成的热胁迫,影响其生长发育与产量。DNA甲基化是表观遗传调控的重要组成部分,在高等植物的基因组表达调控中发挥着重要作用。本试验以耐高温品种苏棉16号和高温敏感品种石185为供试材料,研究棉花花铃期高温胁迫前后DNA甲基化的变化,通过甲基化敏感扩增多态性(methylation sensitive amplified polymorphism,MSAP)技术,探讨了不同温度下棉花叶片DNA甲基化水平和甲基化模式变化。结果显示,经过高温处理后,耐高温棉花品种苏棉16号和高温敏感棉花品种石185的甲基化水平都表现为上升,苏棉16号半甲基化率高于全甲基化率,而石185全甲基化率高于半甲基化率;棉花在受到高温胁迫后,甲基化和去甲基化同时发生,但耐高温品种苏棉16号主要发生甲基化,高温敏感品种石185主要发生去甲基化。本研究结果表明高温能够诱导棉花甲基化水平的提高,同时DNA甲基化水平及状态变化与棉花耐热性存在重要关系。 High temperature on cotton caused by heat stress, affecting its growth and yield. DNA methylation is an important part of epigenetic regulation and plays an important role in the regulation of genomic expression in higher plants. In this study, the high temperature variety Sumian 16 and high temperature sensitive variety Shi 185 were used as materials to study the changes of DNA methylation during the cotton boll stage under high temperature stress. Methylation sensitive amplified polymorphism (methylation sensitive amplified polymorphism polymorphism and MSAP techniques were used to investigate the changes of DNA methylation and methylation patterns in cotton leaves under different temperatures. The results showed that the methylation level of high temperature cotton variety Sumao 16 and high temperature sensitive cotton variety 185 increased after the high temperature treatment, the half methylation rate of Su cotton 16 was higher than the full methylation rate, While the methylation rate of stone 185 was higher than that of the half-methylation rate. After high temperature stress, the methylation and demethylation of cotton occurred simultaneously. However, the high temperature resistant variety Sumian 16 was mainly methylated and hypersensitive Variety stone 185 occurs mainly demethylation. The results of this study indicate that high temperature can induce the enhancement of the cotton methylation level, and the DNA methylation level and the change of the state have an important relationship with the heat resistance of the cotton.