巨峰葡萄主梢和副梢坐果与内源激素的关系

巨峰葡萄副梢坐果率、有种子果粒率、果粒的平均种子数明显高于主梢。在小花发育过程中主梢的小花重、小花纵径、横径明显重于或大于副梢。主梢花的子房壁明显厚于副梢，子房壁的细胞层数也多于副梢，但子房壁的细胞大小两者之间没有差异。另外胚珠、珠心大小也没有差异。主梢小花中的IAA与细胞分裂素水平较高，ABA水平较低，副梢小花中的GA水平较高。开花前2～3周用高浓度的NAA与CPPU处理副梢小花则加重落花落果。由此可见，开花前小花中较高水平的IAA与细胞分裂素很可能是加快小花发育和引起落花落果的原因。

Relationship Between Berry Set and Endogenous Plant Growth Substances in Primary and Secondary Flowers of Kyoho Grapevine

The difference in berry set between primary flowers （PF） formed on the primary shoots and secondary flowers （SF） on lateral shoots of Kyoho grape variety was investigated ．The three year averaged percentage of berry set， number of seeded berries per cluster， and seeds per berry in secondary flowers were significantly higher than those in PF． Moreover， most of the seeded berries in the PF was one seed per berry， though the number of berries containing two， three or four seeds per berry increased in the SF． The sizes of florets and pistils in SF at anthesis were smaller than those in PF． This difference was related to the suppression of cell division in the ovary wall of florets in the SP． However， there was no significant difference in the ovule and nucellus sizes．Two or three weeks before anthesis， the levels of IAA and cytokinin in the florets of SF were significantly lower than those in the florets of PF． While ABA level， which is considered to inhibit IAA and cytokinin activities， was always higher in the SF than in the PF． GA level was some what higher until anthesis in the florets of SF． The treatments of NAA as an auxin and CPPU as a cytokinin like substance to SF about 2～3 weeks before anthesis significantly induced an enhanced flower shatter with increasing concentration of treatments． From these findings， it is suggested that the increase in berry set of SF may be attributed to the low levels of IAA and cytokinin．