赤霉素诱导甘蔗节间伸长与内源激素变化的关系

探讨外源赤霉素对甘蔗节问伸长的效果及其与茎尖内源激素的变化关系.试验以新台糖22号为材料,在伸长初期以200 mg/L浓度的赤霉素进行叶面喷施,对照喷清水.结果表明,赤霉素处理的株高在各个时期显著高于对照,而且在处理后7,14和28 d分别比对照提高了17.32%、14.50%和8.35%.赤霉素处理引起植株表现的高度优势一直保持到后期,节间伸长效果主要集中在中部.赤霉素处理的CA,含量显著高于对照:ABA含量则相反,赤霉素处理的均显著低于对照.赤霉素处理的乙烯释放量稍低于对照,IAA含量从第7 d开始稍高于对照的;赤霉素处理对ZR含量的影响不明显.赤霉素处理的ABA/LAA的比值显著下降,ZMAA和EH.IAA的比值也有一定程度的下降,而提高了GA_3/IAA的比值.这说明外源赤霉素促进甘蔗节间的伸长可能主要通过调节ABA和赤霉素含量,其次是乙烯释放量和生长素含量,最终达到调节节间伸长效果.

Relationship Between Gibberellin-induced Internode Elongation and Endogenous Hormone Changes in Sugarcane

The sugarcane cultivar ROC22 was treated with giberrellin to investigate the relationship between intemode elongation and the changes of endogenous hormone in sugarcane. The ROC22 plants were sprayed with 200mg/L of gibberellin at the early elongation stage, with water spray as control. The results showed that the plant height at different stages was significantly higher in the gibberellin treatment than in the control, increasing by 17.32%, 14.5% and 8.35% respectively at days 7, 14 and 28 after spraying. The plants treated with gibberellin maintained taller than the control until at the late stage, and the internode elongation induced by gibberellin was mainly concentrated in the central part of the stem. The content of GA_3 in the stem tip was significantly higher in the gibberellin treatment than in the control, whereas opposite changes were observed for the content of ABA, which decreased by 4.94% in the gibberellin treatment and was significantly lower than that in the control. The ethylene production was slightly lower in the gibberellin treatment than in the control, while the content of IAA was slightly higher in the gibberellin treatment since the 7th day after treatment, and the content of ZR were not significant between the control and the gibberellin treatment. After gibberellin treatment, the ratio of ABA/IAA was significantly lower than that of the control, and the ratios of ZR/IAA and EH/IAA were a bit lower than those of the control, but the ratio of GA3/IAA was increased in the treatment than in the control. These results suggest that the internode elongation might mainly be regulated by the contents of ABA and gibberellin, followed by the content of IAA and ethylene releasing rate in sugarcane.