设施条件下4个中熟砂梨品种果实发育及 糖酸含量的变化

对秋荣、圆黄、幸水和雪青4个砂梨在大棚设施栽培条件下的果实发育规律和糖酸含量变化规律进行研究。结果表明：秋荣、幸水和雪青3个品种均在7月上旬成熟，以秋荣最早，圆黄7月中旬成熟。果实发育过程中，4个中熟品种糖的动态变化基本一致，圆黄果实中总酸含量的变化与其它3个品种有明显差异，糖酸比以6月27日采摘的幸水最高，达到77.96。圆黄、幸水和秋荣都是优良的大棚适栽中熟品种，可在生产上推广应用。

Changes in Fruit Development and Contents of Sugar and Acid of Four Mid-Maturity Sand Pears in Protected Cultivation

The law of fruit development and changes in contents of sugar and acid of four mid-maturity sand pears in protected cultivation was studied. It was showed that Akibae, Kousui and Xueqing all matured in the first ten days of July, among of them, Akibae matured at first and Wonwhang matured in the middle ten days of July. The dynamic changes of sugar of four mid-maturity cultivars basically accorded with each other; there was evident difference between the changes of the contents of total acid of Wonwhang and other three cultivars during fruit development. The ratio of sugar and acid of Kousui picked on June 27 was 77.96 and the biggest of the four cultivars. As a result, Wonwhang, Kousui and Akibae are good mid-maturity cultivars, fitting to be grown in greenhouse and may be extended and applied widely.