不同授粉处理对沙田柚果实发育中内源激素水平变化的影响

沙田柚自花授粉果实的重量和体积均低于异花授粉处理。与未授粉子房相比,授粉子房迅速膨大。授粉处理可使子房内源激素(ＩＡＡ)、赤霉素(ＧＡ１＋３)、细胞分裂素(ＣＴＫｓ)和脱落酸(ＡＢＡ)水平急剧上升,异花授粉处理更明显。未授粉的子房内源生长促进类激素含量保持低水平,生长抑制类激素(ＡＢＡ)水平上升,这种激素水平的失衡最终造成未授粉子房的迅速凋落。果实生长发育初期,自花授粉幼果内源激素促进类激素含量低于异花授粉处理,ＡＢＡ水平明显高出后者,果实迅速增长期间,内源ＩＡＡ和ＧＡ１＋３有两个明显的高峰期,显示ＩＡＡ和ＧＡ１＋３含量与果实迅速膨大有密切关系。果实发育后期直至成熟,内源ＡＢＡ水平逐渐升高。测定果实发育整个过程的ＡＢＡ/(ＩＡＡ＋ＧＡ１＋３＋ＣＴＫｓ),未发现规律性的变化。

Effect of Pollination on the Change of Endohormones in the Fruit of Shatianyou Pomelo Variety

Observation showed that the fruit growth and development of shatianyou pomelo variety were expressed as a curve.The growth rate of fruit weight, vertical and horizontal diameter was fast at the mid-developing stage.The weight and volumeof self-pollinated fruit were smaller than cross-pollinated ones.Contrast to non-pollinated ovary,the pollinated ovary ex-panded rapidly.Pollination could increase endogenous IAA, GA1 3,CTKs,ABA contents, and the effect of cross-pollinationwas more remarkable;the endogenous promotive hormone contents in non-pollinated ovary kept in low level,but ABA con-tent was increased.The break of endogenous hormone balance led to rapid drop of non-pollinated ovaries.At the initial stageof fruit growth,promotive hormone contents of self-pollinated fruit were lower than cross-pollinate treatment,and ABA levelwas significantly higher than the latter,it may be the main reason of high fruit abscission rate of self-pollinated ones duringphysiological fruit drop period. During fruit fast-expanding period, the contents of IAA and GA1 3 reached twice peak, so it issuggested that there is a close relationship between fruit fast-swelling and GA1 3, IAA contents. The regular changes were notfound in ABA/(IAA GA1 3 CTKs) during fruit growth.