Changes in the Endogenous Hormones and Carbohydrate Contents in Crocus sativus L. during Floral Bud Differentiation

Purpose Mechanism research about the initiation and development of flower bud in Crocus sativus L., investigating the relationship between flower bud differentiation and the contents of endogenous hormones and carbohydrate metabolism, is of invaluable for production.

Method The methods of ELISA and anthrone colorimetry were used to study the changes of endogenous hormones and carbohydrate contents, and the activities of amylase in the terminal buds (flower buds).

Result The contents of IAA showed " falling-rising-falling” trends; the contents of GAs showed " falling-rising-falling-rising” trends; the contents of ABA and ZRs showed " rising-falling-rising” trends. The peak ratio of ABA/GAs, ABA/IAA and ZRs/GAs appeared in the stage of FD, then descended below the level of the stage of VP. The contents of soluble sugar showed the single-peak curve trends, the contents of starch showed the single-valley curve trends; the activities of α-amylase and β-amylase increased on a whole and reached the maximum value in the stage of DP, in the developing process of flower bud differentiation.

Conclusion In sum, low levels of IAA and GAs, and high levels of ABA and ZRs could help induce flower bud differentiation; high ratios of ABA/GAs, ZRs/GAs and ABA/IAA also were favorable for transition of flower bud from vegetative growth to reproductive growth; high levels of soluble sugar content and amylase activity also could promote the differentiation of flower bud and flower formation.