Comparison of Physiological Properties Between Dwarf and Vine-type Cucumbers (Cucumis sativus Linn.)

Dwarfism is one of the most important traits in crop breeding. In this study, a dwarf cucumber D0462 and a vine NA129 were taken as experimental materials. The metabolism of hydrogen peroxide (H2O2) and superoxide anion radical (O2−•), activities of antioxidant enzymes, and the levels of endogenous hormones of the two cultivars were compared. In the whole growth period, D0462 maintained higher H2O2 and O2−• levels than NA129. The activities of SOD (superoxide dismutase), CAT (catalase), APX (ascorbate peroxidase) and IAAO (indoleacetic acid oxidase) in D0462 were found higher than those in NA129. The contents of gibberellic acid (GA3), indole-3-acetic acid (IAA), zeatin riboside (ZR) and jasmonic acid (JA) in internode were determined by enzyme-linked immunosorbent assay (ELISA). The internode of D0462 remained lower levels of GA3, IAA, and ZR. In contrast, JA level in internode of D0462 was higher than that of NA129. Compared with NA129, the cell mumbers in internode of D0462 did not change, but cell size evidently decreased. The chloroplasts in mature mesophyll D0462 exhibited swollen filled with starch grains instead of regular oval ones, and thylakoids of chloroplast swelled and became ambiguous.