糯米糍荔枝坐果与内源激素的关系

A Study of Fruit-set Physiology in Relation to Endogenous Hormones in Litchi(Litchi Chinensis Sonn. Nuomici) Fruits

授粉受精是糯米糍荔枝花后子房正常坐果的刺激因子，授粉受精后子房ＡＢＡ从开花当天的最高水平急剧下降，而ＩＡＡ、ＧＡｓ和ＣＴＫ水平都升高，并在花后１２天达最高值。坐果期内源ＡＢＡ水平有３次明显高峰，分别出现在３次生理落果高峰前１周左右；内源ＩＡＡ和ＧＡｓ则有２次明显较高水平，分别与果皮和假种皮的迅速生长有关；而ＣＴＫ在胚败育前保持高水平，胚败育后才降至较低水平。荔枝果实中ＧＡｓ类有ＧＡ３、ＧＡ（４＋７）、ＧＡ５、ＧＡ９，ＣＴＫ类有ＺＴ、ＺＲ、ｄｉＨＺ、ｄｉＨＺＲ，并分别有不同的变化特点，ＧＡｓ和ＣＴＫ的构成和含量在胚乳解体和胚中途败育期的急剧变化可能与糯米糍荔枝的连续性生理落果现象有关。

Contents of endogenous hormones in Litchi (Litchi chinensis Sonn. cv. Nuomici) fruits were determined during fruit development. The results revealed that pollination and fertillization stimulated the increase of CTK. IAA and GAs levels and decrease of ABA level in ovary after anthesis, which were the basis for fruit-setting. There were three peaks of ABA level which preceded separately the second to the fourth peak of physiological fruit drop, and two higher levels of IAA and GAs which were correlated with the rapid growth of pericarp and aril respectively during fruit development. The CTK level maintained higher before embryo abortion, after which it decreased.GA3, GA(4+7), GA5, GA9, ZT, ZR, diHZ, and diHZR.were also determined in litchi fruits, which changed greatly during fruit-setting period. The intense changes of Gas and CTK composition and contents, which was coincident with the endosperm disintegration and embryo abortion, seemed to be related to the continuous physiological fruit drop.