Qiannan Diao¹ , Yanyan Cao¹ , Xuejun Jiang² , Youyuan Chen¹ , Yongping Zhang¹

1 Horticultural Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai 201106, China
2 Jinshan District Agriculture Technology Extension Center, Shanghai 201599, China
Author    Correspondence author
International Journal of Horticulture, 2023, Vol. 13, No. 4   doi: 10.5376/ijh.2023.13.0004
Received: 21 Mar., 2023    Accepted: 28 Mar., 2023    Published: 06 Apr., 2023

This article was first published in Molecular Plant Breeding in Chinese, and here was authorized to translate and publish the paper in English under the terms of Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Diao Q.N., Cao Y.Y., Jiang X.J., Chen Y.Y., and Zhang Y.P., 2023, Effect of powdery mildew on physiological and biochemical indexes of different melon varieties, International Journal of Horticulture, 13(4): 1-8 (doi: 10.5376/ijh.2023.13.0004)

In order to study the effect of melon powdery mildew on the physiological indexes of different melon varieties, high resistant to melon powdery mildew variety ‘16-6’, medium resistant to melon powdery mildew variety ‘04-38’, and highly susceptible melon powdery mildew variety ‘15B-42’ were used as materials. The activities of antioxidant defense system enzymes, the contents of malondialdehyde (MDA), soluble protein and chlorophyll, and the photosynthetic indicators in leaves of melon seedlings were assayed after inoculated with powdery mildew 1 d, 3 d, 5 d, 7 d and 9 d. The results showed that after inoculation with powdery mildew, except for superoxide dismutase (SOD) activity, the defense enzyme activities, including peroxidase (POD), catalase (CAT), ascorbic acid peroxidase (APX), phenylalanine ammonialyase (PAL) and polyphenol oxidase (PPO) and the MDA content in leaves of the three melon varieties showed a trend of first increase and then decrease, and the increment amplitude of the resistant lines was larger than that of the susceptible lines ; the contents of chlorophyll and soluble protein, and the five photosynthetic indicators, including the net photosynthetic rate (Pn), the stomatal conductance (Gs), the intercellular CO₂ concentration (Ci), the transpiration rate (Tr) and the stomatal limitation (Ls) of leaves of the three melon varieties decreased with different amplitude after inoculation , and the decrement amplitude of the resistant lines was smaller than that of the susceptible lines.

Melon; Powdery mildew; Defense enzyme activity; Photosynthetic characteristics