Effects of Exogenous Polyamine Application on Flower Bud Differentiation and Flower Development in Muskmelon
QI Hong-yan，HUANG He，ZHANG Duo-jiao
College of Horticulture，Shenyang Agricultural University，Key Laboratory for Protected Horticulture，Ministry of Education，Key Laboratory of Liaoning Province for Protected Horticulture，Shenyang 110866，Liaoning，China
Abstract：In order to investigate the influence of exogenous polyamine application on the flower bud differentiation and flower development muskmelon（Cucumis melo L. var. makuwa Makino），‘Yongtian No. 3’was used in this experiment．The flower bud differentiation and flower development were investigated with spraying different concentrations of putrescine（Put）and spermidine（Spd）after the cotyledon just came out of the soil．The process of flower bud differentiation and the morphological observation were studied in muskmelon by means of paraffin-cut section．The contents of endogenous hormones and polyamine in flower bud and leaves were examined．The results showed that spraying Put and Spd increased the ratio of female flowers of the first node on the sub-vine，promoted the flower bud differentiation，and advanced the florescence．After spraying high concentration of Put and low concentration of Spd，IAA content increased in leaves，but ZT content decreased，and ABA content reached peak in advance．The Spd content in flower bud reached its peak earlier after spraying polyamine|while the level of spermine（Spm）was relatively low and changed irregularly．Three kinds of endogenous polyamine contents in flower buds were higher than that in the leaves．The appropriate concentration of Put and Spd is 1×10-3 mol•L-1 and 1×10-4 mol•L-1，respectively．
