Relationships Between Endogenous Hormone Contents and Cytoplasmic Male Sterility in Sugarbeet

【Objective】This study was designed to elucidate the relationship between endogenous hormone contents and cytoplasmic male sterility of sugarbeet. 【Method】Enzyme-linked immunosorbent assays (ELISA) was used to determine indoleacetic acid (IAA), cytokinin, abscisic acid (ABA) and gibberellin (GA3) contents and the ratio of these endogenous hormones to ABA, respectively. These endogenous hormones were taken from functional leaves and buds of two pair of monogerm cytoplasmic male sterile (CMS) lines with significant different phenotype and O-type line sugarbeet during vegetative and reproductive period. 【Result】ABA, IAA and GA3 contents in leaves of O-type line were significantly higher than those of CMS lines, except DHZR, IPA, ZR, during vegetative period, to the early stage of flower, IAA, ABA, DHZR, ZR, GA3 contents of CMS lines were higher than those of O-type line, except IPA; while in buds IAA, ABA, ZR and GA3 contents of CMS lines were lower than those of O-type line. The regular changes of theses endogenous hormones contents in organs were found in leaves during vegetative period and at early stage of flower, and in buds during florescence. For the three periods, compared with O-type line, the ratios of IAA, ZR and GA3 to ABA for CMS lines were 0.55, 1.43, 1.64; 2.66, 1.55, 1.49; and 1.14, 1.60, 1.53 times, respectively. 【Conclusion】The changes ofendogenous hormones contents and CMS are closely connected. Decrease in ratio of IAA to ABA, while increase in ratios of ZR and GA3 to ABA in bud, and increase in ratios of IAA, ZR and GA3 to ABA in leaves during vegetative period and early stage of flower were important factors involved in CMS. This study has provided a fundamental basis for further research on physiological mechanism and regulation of cytoplasmic male sterility in sugarbeet.