Abstract: In order to elucidate the effect of zinc on the growth and development of potato under drought stress, the tissue culture seedlings of potato cultivar “Atlantic” , and the medium with different zinc contents (0, 8.6, 17.2, 25.8, 34.4 and 43 mg/L) were used as the test material. After cultured for 15 d, the medium was replaced with medium containing 20% PEG6000 to simulate drought stress for 15 d. The phenotype, antioxidant enzyme activity and osmotic adjustment substance content of the tissue culture seedlings were determined, and the drought resistance was analyzed. The results showed that zinc had a significant effect on the growth of potato tissue culture seedlings under PEG stress. The tissue culture seedlings performed best when the zinc content of the medium was 17.2 mg/L. Among them, the fresh weight and plant height increased by 50% and 34.66% respectively when the zinc content of the medium was 17.2 mg/L compared with that of the normal MS treatment; the activities of catalase (CAT), superoxide dismutase (SOD) and Pro Compared with that of the normal MS treatment, the content increased by 9.88%, 10% and 3.88% respectively, and the MDA content decreased by 21.86% compared with that of the normal MS treatment. The results showed that exogenous application of an appropriate amount of zinc could promote the growth and development of tissue culture seedlings, and when the zinc content of the medium was 17.2 mg/L, the drought tolerance of potato tissue culture seedlings could be significantly improved. The results provided a basis for further elucidating the mechanism of zinc regulation of potato drought resistance.

Key words: potato, zinc, drought stress, antioxidant enzyme activity, phenotype