Research Progress on Waterlogging Tolerance of <i>Cucurbit</i> Crops

Abstract

As one of the most frequent natural disasters in China, flooding seriously affected the plant growth and development, decreased the yield and quality of  Cucurbit crops seriously, and thus led to huge economic losses. Here, we reviewed the effects of waterlogging stress on root growth, respiration, leaf photosynthesis and reactive oxygen species metabolism in  Cucurbit  crops. In order to response to waterlogging, the plants promote the formation of adventitious roots mediated by ethylene, lower the aerobic respiration, and induce the activity of antioxidant enzymes and the synthesis of antioxidant substances. Moreover, we summarized the identification indexes of waterlogging tolerance such as the loss rate of chlorophyll. In addition, we reviewed the progress of genetic breeding for waterlogging tolerant cultivars from three aspects, including traditional breeding, molecular marker-assisted breeding and genetic engineering breeding. Besides, we highlighted the future research direction. The purpose of this review was to understand the mechanism of waterlogging tolerance and to provide a theoretical basis for the breeding of waterlogging resistant cultivars in  Cucurbit  plants.