苹果坐果的激素调控

以红富士苹果为试材，花朵数为5的花序，其坐果率明显高于花朵数为4的花序。开花前，花朵数为5的花序，其花朵子房内GAs，、Z浓度明显高于后者；开花后，后者GAs仍然低于前者，但Z浓度、Z／GAs比值则迅速增加并明显高于前者。蕾期喷施GA4 7DCPTA、Glu、SA可以明显提高花朵数为4的花序的坐果率。

Study on the Hormonal Regulation of Fruit Setting in Apple Tree

Both 11- and 12-year-old ' Red Fuji, apple trees (Malus domestica Mill) were used as materials to test the relation between the number of flowers per inflorescence and fruit set and the contents of endogenous hormones in the ovary . The results showed tha higher thet sets related to number of flowers per inflorescence were obtained in the order of 6-flower inflorescence > 5-flower inflorescence > 4-flower inflorscence (Fig.1). From 4 d before full bloom (Bre)to 1 d after full bloom (AFB), the contents of both GAs and Z, in the ovary of 5-flower inflorescence were higher than tha of 4-flower inflorescence. Lower content of GAs or both higher Z contents and higher Z/GAs ratio were fomed in the ovaries of 4-flower-inflorescence than in tha of 5-flower-inflorescence in 2 ~ 3 d AFB. No remarkable difference between 4-and 5-flower inflorescences was observed in the contents of either IAA or ANA from 4 d BFB to 3 d AFB (Fig. 2).Foliar sprays of both GA4 7 200mg/L, 6-BA 100 mg/L, paclobutrazol 200 mg/L, Glu 100 mg/L, or DCPTA 500 mg/L in 1995 on 11-year-old' Red Fuji' apple trees and 6-BA 100 mg/L,Glu 100mg/L, or SA 160mg/L in 1997 on 10-year-old' Red Fuji' apple trees were made at balloon flower. Treaments with GA4 7 and DCPTA significantly increased fruit set of 4- or 5-flower iaflorescence in 1995. 6-BA treatment also increased fruit set of 4-flower infloresecence in 1995. In 1997, all treatments with 6-BA, Glu and SA increased fruit set of the treated trees, particularly with the 4-flower inflorescences.