Abstract: Soil drought and salinization have serious effects on plant growth and development. It is very important to screen genes suit-able for evaluating drought resistance and salt tolerance of cotton. Two drought-resistant and salt-tolerant cotton varieties and two drought-sensitive and salt-sensitive cotton varieties were used as materials to detect the expression difference of stress-resistant related transcrip-tion factorsGhHsfA7,GhbZIP15andGhNAC2at transcriptional level by qRT-PCR. The expression differences of stress-resistant related transcription factorsGhHsfA7,GhbZIP15andGhNAC2were detected at transcriptional level. At that same time, the changes of five com-mon physiological indexes for stress resistance identification, and the correlation between the expression of these three genes and physio-logical indexes were analyzed. The results showed that the relative expression levels ofGhHsfA7,GhbZIP15, andGhNAC2were predomi-nantly in sensitive cotton under 6 h PEG stress and 3 h NaCl stress, Which were significantly lower than those in the tolerant varieties.Under drought and salt stress, there were significant or extremely significant differences in physiological indexes between cotton and thecontrol, and the relative changes of Pro, SOD and POD in tolerant cotton varieties were greater than those in sensitive cotton varieties,while the relative changes of MDA and EL were smaller than those in sensitive cotton varieties. Correlation analysis showed thatGhHsfA7,GhbZIP15,GhNAC2had significant or extremely significant correlation with MDA, Pro, SOD, POD, and EL. Therefore, the expression of the transcription factorsGhHsfA7,GhbZIP15andGhNAC2can be used as molecular markers for the identification of drought resistanceand salt tolerance of cotton, which lays a foundation for the study of stress resistance mechanism of cotton.

Key words: cotton, PEG stress, NaCl stress, transcription factors, physiological index, correlation