Effects of Flooding Stress on Growth and Root Physiology and Biochemistry of Grafted Red-seed Watermelon Seedlings.

[Objectives] This study was conducted to explore how to improve the waterlogging tolerance of red-seed watermelon through grafting, to provide a theoretical basis for its cultivation in rainy season. [Methods] The effects of flooding stress on the growth and root physiological and biochemical characteristics of grafted and own-rooted red-seed watermelon seedlings were studied using Luffa as rootstocks and "Zhongxin 1" red-seed watermelon as scions. [Results] After flooding stress, the biomass and root activity of grafted seedlings of red-seed watermelon were significantly higher than those of own-rooted seedlings. With the prolongation of flooding stress time, the soluble sugar and proline content showed a trend of first increasing and then decreasing, and the grafted seedlings had a larger increase and a smaller decrease, and were always significantly higher than own-rooted seedlings in the same period. The content of malondialdehyde in the root system of grafted seedlings increased first and then decreased, while it continued to increase in own-rooted seedlings, and the increase in own-rooted seedlings was significantly greater than that in grafted seedlings during the same period. [Conclusions] Grafting on Luffa rootstocks could improve waterlogging tolerance of red-seed watermelon. [ABSTRACT FROM AUTHOR]