陆川油茶现蕾期至谢花期主要器官中内源激素的变化规律

Change rules of endogenous hormones in main organs of Camellia vietnamensis from budding stage to flowering stage

【目的】内源激素对植物生长发育具有十分重要的调控作用,探究油茶现蕾期至谢花期内源激素含量及比值的变化规律,为油茶的开花调控提供理论参考依据。【方法】以7年生陆川油茶为试材,在其现蕾期至谢花期(7月中旬至翌年1月中旬)每隔15 d采集花蕾、叶芽、枝条、功能叶片样品各1次,采用酶联免疫吸附法(ELISA)测定各器官中吲哚-3-乙酸(IAA)、赤霉素(GA_(3))、玉米素核苷(ZR)、脱落酸(ABA)的含量,分析4种内源激素的变化规律。【结果】花蕾中的IAA含量呈下降趋势,8月15日达到最高值(155.96 ng/g);叶芽中的IAA含量先升后降,9月15日达到最高值(72.07 ng/g);枝条、功能叶中的IAA含量相差不大,其变化均较平缓,分别于12月15日、10月30日达到最高值(分别为35.53、32.58 ng/g)。花蕾、枝条中的ABA含量均先升后降,均于10月15日达到最高值(分别为213.39、110.41 ng/g);叶芽中的ABA含量先降后升,1月15日达到最高值(113.15 ng/g);功能叶中的ABA含量呈“双峰”变化趋势,12月30日达到最高值(34.98 ng/g)。4个器官中的GA_(3)、ZR含量均相对较少,均极显著低于其IAA、ABA含量,且均无明显的变化规律。花蕾中的IAA、GA_(3)含量,在多数情况下,均高于其营养器官中的IAA、GA_(3)含量。各器官中不同内源激素的比值均无明显变化趋势。初花期,花蕾、枝条、功能叶的GA_(3)/IAA值均极显著上升,而叶芽的GA_(3)/IAA值却无明显变化趋势。花蕾定型前,花蕾的IAA/ABA值极显著高于其他3个器官的IAA/ABA值;花蕾定型后,其IAA/ABA值由2.92迅速下降至0.43。在多数情况下,功能叶的GA_(3)/ABA、ZR/ABA、ZR/IAA值均极显著高于其他3个器官的比值。【结论】陆川油茶器官生长和构建不是受单种内源激素的影响,而是多种内源激素共同作用的结果,IAA/ABA之值高能够促进陆川油茶花蕾的形成和生长。花蕾中的IAA、GA_(3)对陆川油茶花蕾的形成及开花均有明显的促进作用,各器官中的IAA和ABA均存在拮抗作用。

【Objective】Endogenous hormones play a very important role in the regulation of plant growth and development.To explore the change rules of the content and ratio of endogenous hormones from bud stage to flowering period of Camellia oleifera,and provide theoretical reference for the regulation of flowering of C.oleifera.【Method】Taking 7-year-old C.vietnamensis as the test material,flower bud,leaf bud,branch and functional leaf samples were collected every 15 days from budding stage to flower withering stage(from mid July to mid January of the next year).The contents of indole-3-acetic acid(IAA),gibberellin(GA_(3)),trans-zeatin-riboside(ZR)and abscisic acid(ABA)in various organs were determined by enzyme-linked immunosorbent assay(ELISA).The changes of four endogenous hormones were analyzed.【Result】The content of IAA in flower buds showed a decreasing trend,and reached the highest value on August 15th(155.96 ng/g).The content of IAA in leaf buds increased firstly and then decreased,and reached the highest value on September 15th(72.07 ng/g).The content of IAA in branches and functional leaves had little difference,and the changes were gentle,reaching the highest value on December 15th and October 30th,respectively(35.53 ng/g,32.58 ng/g).ABA content in buds and branches increased firstly and then decreased,and reached the highest value on October 15th(213.39 and 110.41 ng/g,respectively).ABA content in leaf buds decreased firstly and then increased,and reached the highest value on January 15th(113.15 ng/g).ABA content in functional leaves showed a“double peak”trend,and reached the highest value on December 30th(34.98 ng/g).The contents of GA_(3)and ZR in the four organs were relatively small,and significantly lower than those of IAA and ABA,and there was no obvious change rule in all of them.The contents of IAA and GA_(3)in flower buds were higher than those in vegetative organs in most cases.There was no obvious trend in the ratio of endogenous hormones in different organs.GA_(3)/IAA of bud,branch and functional leaf increased significantly at the initial flowering stage,but there was no significant change in GA_(3)/IAA of leaf bud.The IAA/ABA value of the flower bud was significantly higher than those of the other three organs before bud setting.The IAA/ABA value decreased rapidly from 2.92 to 0.43 after bud formation.In most cases,the values of GA_(3)/ABA,ZR/ABA and ZR/IAA in functional leaves were significantly higher than those in the other three organs.【Conclusion】Organ growth and construction of C.vietnamensis was not affected by a single endogenous hormone,but the result of the joint action of multiple endogenous hormones.High IAA/ABA ratio could promote the formation and growth of C.vietnamensis buds.IAA and GA_(3)in flower bud promoted the formation and flowering of C.vietnamensis,while IAA and ABA in various organs had antagonistic effects.