Changes of endogenous hormones in Lilium davidii var. unicolor bulbs during bulb development and storage at low temperature for dormancy release

Abstract

Changes of endogenous hormones in mother scales and in daughter scales of bulbs in Lilium davidii var.unicolor were studied during bulb development and 101 days storage at 2,6 and 10℃ in moist sawdust.The results indicated that ABA concentration both in mother and daughter scales and GA_(3) concentration,ZR concentration in mother scales increased during bulb development,but IAA concentration in all scales and GA_(3) concentration,ZR concentration in daughter scales declined.During the low temperature storage, GA_(3) and IAA level in different parts of bulb had the increase phase, but ABAcontent decreased, and ZR content in daughter scales declined, but which in mother scales had the increase as well as. The notable changes in content of endogenous hormones occurred in the earlier 34 d of storage. Compared among different storage temperature, ABA content had little difference, but GA_(3) content decreased with the rising of temperature. In daughter scales which having plentiful starch, a significantly negative correlation was observed between GA_(3) and ABA content, but had no any correlations in mother scales which had little starch. Path analysis of results showed that metabolism mechanism in mother scales and in daughter scales were different markedly during bulb development and storage at low temperature for dormancy release. Substances changes in mother scales were regulated by endogenous GA_(3), but mostly by endogenous ABA in daughter scales.