白柿果实发育及落果生理

白柿是近几年新引进的一种新兴热带和南亚热带果树。为给白柿花果管理和生长期调控等提供理论依据和实践指导，本文以主栽品种‘W4’白柿为材料，对其生长发育期间的落果规律和果实生长动态进行观测，并分析了落果与正常发育果实中碳素水平和内源激素的含量差异。结果表明：‘W4’白柿在广州地区种植表现出的开花期是在1月下旬至2月初，整个花期约为16天。果实生长发育过程中存在三次落果高峰分别在3月中旬、4月中旬及5~6月，果实的生长符合单S型生长曲线。在果实发育期间，发现正常果及脱落幼果的可溶性总糖含量都呈上升趋势，但正常果的可溶性总糖含量显著高于脱落幼果。同时正常果的赤霉素（GA3）和玉米素（tZ）高于脱落幼果,其脱落幼果中的抑制生长激素脱落酸（ABA）和1-氨基环丙烷-1-羧酸（ACC）显著高于正常果，正常果与脱落幼果的IAA含量在不同时期呈先下降再上升的趋势。在整个果实发育期间正常果的（ ABA+ACC)/(GA3+IAA+tZ)之值曲线变化平稳，而脱落果的（ABA+ACC）/ (GA3+IAA+tZ)之值曲线呈波动变化的趋势,但脱落果中（ ABA+ACC)/(GA3+IAA+tZ)之值显著高于正常果。

Fruit development and fruiting physiology of White sapote

White sapote is a new tropical and subtropical fruit tree introduced in recent years. In order to provide theoretical basis and practical guidance for flower and fruit management and growth period regulation of white persimmon, the main cultivar ''W4'' white persimmon was used as material to observe the fruit dropping rule and fruit growth dynamics during growth and development, and to analyze the difference of carbon content and endogenous hormone content between falling fruit and normal fruit. The results showed that the flowering period of ''W4'' white persimmon in Guangzhou was from late January to early February, and the whole flowering period was about 16 days. There were three peak periods of fruit dropping in mid-March, mid-April and May-June, respectively. The fruit growth was in line with single S-shaped growth curve. During fruit development, it was found that the total soluble sugar content of both normal and shed fruit increased, but the total soluble sugar content of normal fruit was significantly higher than that of shed fruit. At the same time, GA3 and zeatin in normal fruit were higher than those in abscisic acid (ABA) and 1-aminocyclopropane-1-carboxylic acid (ACC). IAA content in normal fruit and abscisic acid showed a trend of first decreasing and then increasing in different periods. The curve of (ABA+ACC)/(GA3+IAA+tZ) of normal fruit changed smoothly during the whole fruit development period. The value of (ABA+ACC)/(GA3+IAA+tZ) in exfoliated fruit fluctuated, but the value of (ABA+ACC)/(GA3+IAA+tZ) in exfoliated fruit was significantly higher than that in normal fruit.