花粉直感效应对香梨幼果脱萼宿萼期内源激素含量的影响

Effect of metaxenia on content of endogenous hormones in young fruit of fragrant pear during persistent calyx and dropping calyx periods

采用4个梨品种(A、B、C、D)花粉为香梨授粉,利用气相和液相(HPLC)色谱技术测定脱萼/宿萼香梨幼果果萼离层部位/顶部和果心部位内源乙烯(ETH))、生长素(IAA)、赤霉素(GA_3)、脱落酸(ABA)含量,研究花粉直感效应对香梨幼果萼片发育过程中萼片脱落/宿存关键期内源激素含量变化与萼片脱落/宿存的影响。结果显示:A、B、C 3个脱萼花粉授粉后,香梨幼果发育初期离区内源ETH急剧升高,并形成2个峰值,对冲了同期离区IAA,诱导离层形成,同期相同部位的ABA与ETH协同促进萼片脱落,脱萼幼果顶部和果心ETH、ABA含量均呈现"M"型波动,且显著高于IAA,GA3,而IAA、GA_3又在幼果发育关键期抑制了ETH、ABA过高水平而可能导致落果,最终形成"母梨";D宿萼花粉授粉后,香梨幼果无论果萼顶部还是果心的IAA、GA_3均呈现"N"型波动,且水平显著高于ETH、ABA,从而促进香梨幼果向"公梨"发育。

The pollen of four pear cultivars（A,B,C and D） and fragrant pear were used to study the effect of metaxenia on the content of endogenous hormones in young fruit of fragrant pear during persistent calyx and dropping calyx periods.The contents of ETH,IAA,GA_3 and ABA in fruit core and calyx abscission layer on the top were determined by high performance liquid chromatography（HPLC）.The result indicated that the content of ETH was higher in the early stage of fruit development pollinated with A,B and C pollen and induced abscission zone development to abscission layer,then calyx abscission was controlled by higher level ETH and ABA endogenous hormones together.IAA and GA_3 inhibited the contents of ETH and ABA to lead to the abscission of fruits.So the young fruit would develop into the female pear.For the treatment pollinated with D pollen,the contents of IAA,GA_3 in calyx abscission layer of fruit tip and fruit core appeared an ＂N＂- type fluctuations,and were higher than the contents of ETH and ABA obviously.This case was beneficial to the development of male pear.