荔枝胚珠中多胺含量变化与胚胎发育的关系

荔枝胚胎发育与胚珠中３种多胺（ＰＡｓ）含量及其比例变化关系密切。试验结果表明：正常发育的胚珠中腐胺（Ｐｕｔ）、亚精胺（Ｓｐｄ）和精胺（Ｓｐｍ）的含量在胚胎发育的各个阶段均高于败育胚珠，并在花后７ｄ即达到最高值，其中Ｐｕｔ的含量最高，随后都呈下降趋势。但正常胚珠中Ｓｐｍ含量在花后２２至３１ｄ（球形胚至心形胚发育阶段）均有所回升，而败育胚珠无此现象。败育胚珠中的Ｓｐｄ和Ｓｐｍ在胚胎败育期的下降速度显著

CHANGES IN POLYAMINE CONTENT IN RELATION TO EMBRYO DEVELOPMENT IN LITCHI OVULES

Three cultivars of 15 to 20-year-old litchi (Litchi chinensis Sonn.) trees grown at Zhangzhou, Fujian Province, were chosen for the experiment. Cultivar Wuye is normal in embryo development, cv. Luhebao being abortive, and cv. Lanzhu having both normal and abortive embryo development. Polymine (PAs) contents in the ovules were tested at 7, 14, 22, 31, 41 and 52 days after anthesis, i.e. from the stage of polar nuclei division to cotyledonary embryo stage, which coincided respectively with each stage of embryo development. The results showed that the contents of putrescine (Put), spermidine (Spd) and spermine (Spm) in normal ovules were all higher than those in abortive ones during the whole embryogenetic process, and reached highest level on the 7th day after anthesis, with Put content being the richest. The contents of these PAs appeared subsequently a downward tendency. However, Spm content increased slightly from the 22nd day to 31st day after anthesis (from globular to heart stages) in normal ovules. But such a phenomenon did not appear in the abortive ones. The contents of Spd and Spm evidently dropped more rapidly in the abortive ovules than those in the normal, which indicats that lower contents and more rapid decrease of Spd and Spm during embryogenetic process might have a close relationship with embryo abortion. The studies also showed that low ratios of (Spd Spm)/Put and Spm/PAs might hindered embryo development. PAs contents hit the peak before the contents of DNA and protein reached maximum, which suggests that PAs might affect embryo development by regulating the synthesis of biomacromolecules.