紫梗籽银桂种子发育过程中内源激素含量的动态变化研究

Changes of Endogenous Hormone Contents in Seed Development of Osmanthus fragrans ‘Zigengziyin’

[目的]通过分别测定紫梗籽银桂种子发育过程中胚和胚乳的4种内源激素含量的变化,探讨该过程中内源激素的变化规律。[方法]以紫梗籽银桂种子为研究材料,分别测定其种子发育过程不同时期胚和胚乳内源激素生长素(IAA)、赤霉素(GA_(3))、玉米素核苷(ZR)、脱落酸(ABA)含量的变化。[结果]紫梗籽银桂种子发育过程中胚的GA_(3)含量整体呈下降趋势,ABA含量呈不断上升的趋势,IAA、ZR含量均呈先上升后下降再上升的趋势;GA_(3)/ABA比值不断下降,IAA/ABA、ZR/ABA的比值先下降后上升,胚中GA_(3)/ABA比值的变化幅度大于IAA/ABA、ZR/ABA的比值变化;胚乳中GA_(3)、IAA、ZR含量总体呈下降的趋势,ABA含量呈先下降、后上升并保持平稳的趋势;GA_(3)/ABA、IAA/ABA、ZR/ABA_(3)个比值总体均呈现下降趋势,胚乳中GA_(3)/ABA比值的变化幅度大于IAA/ABA、ZR/ABA的比值变化。[结论]紫梗籽银桂种子发育过程中胚和胚乳的4种内源激素含量的动态变化呈现一定的规律性,胚及胚乳中GA_(3)/ABA比值均呈下降趋势,变化幅度均大于IAA/ABA、ZR/ABA的比值变化,GA_(3)/ABA水平的高低可能是影响种子发育的关键因素。

[Objective]To investigate the changes in the content of four endogenous hormones in the em-bryo and endosperm during the development process of Osmanthus fragrans‘Zigengziyin’seeds,and to explore the patterns of endogenous hormone changes during this process.[Method]Osmanthus fragrans‘Zigengziyin’seeds were used to measure the contents of endogenous hormones auxin(IAA),gibberellin(GA_(3)),zeatin nucleoside(ZR)and abscisic acid(ABA)in embryo and endosperm during different periods in seed development.[Result]During the development of seeds,GA_(3) contents in embryo decreased,but the ABA contents in embryo increased.IAA and ZR contents in embryo increased firstly then decreased and increased finally.The Ratio of GA_(3)/ABA also decreased continuously.Both the ratios of IAA/ABA and ZR/ABA decreased firstly then increased.The change in GA_(3)/ABA in the embryo was greater than the change in the ratios of IAA/ABA and ZR/ABA.The contents of GA_(3),IAA,and ZR in the endosperm de-creased during the development,while the content of ABA first decreased,then increased,and remained stable.The ratios of GA_(3)/ABA,IAA/ABA,and ZR/ABA decreased,and the variation amplitude of GA_(3)/ABA ratio in endosperm was greater than that of IAA/ABA and ZR/ABA.[Conclusion]The dynamic changes in the content of four endogenous hormones in the embryo and endosperm during the seed development process of O.fragrans‘Zigengziyin’exhibite a certain regularity.The ratio of GA_(3)/ABA in embryo and endo-sperm both decrease,and the changes are greater than of the changes in IAA/ABA and ZR/ABA.The ra-tio of GA_(3)/ABA may be the key factor affecting seed development.