烤烟生长发育的低温诱导研究 Ⅰ、苗期低温诱导对烤烟顶芽发育及激素含量的影响

Studies of low-temperature induction on the development of flue-cured tobacco The influence of low-temperature to the development and plant hormones in the apical budof tobacco at seedling stage

以烤烟(Nicotiana tabacum)K326为材料,研究了低温诱导下烟株顶芽发育及顶芽内激素含量的变化,研究结果表明烤烟(K326)到第6片真叶时才对低温敏感,而低温诱导只有持续到7叶期才能维持低温诱导的结果.各处理的烟苗4～10叶期顶芽的组织解剖特征没有明显差异,都处于营养分生组织阶段.但低温诱导影响了顶芽内几种激素的变化,苗期烟草顶芽内ZRs含量极低;各处理的烟苗在低温诱导期间,顶芽内IAA含量低于对照,低温诱导结束后,IAA含量高于对照,对照和6叶期前低温处理的烟苗顶芽内IAA变化不大,低温诱导到6叶、7叶、8叶、9叶、10叶的各处理顶芽内IAA含量在7叶期出现高峰;对照和低温诱导到7叶期前的各处理顶芽内GA3含量在6叶期出现峰值,低温诱导到7叶及7叶以后的各处理在6～7叶出现峰值,且在8叶之前GA3含量高于对照;ABA的峰值出现在8叶期,低温诱导使顶芽内ABA升高.

Using flue-cured tobacco K326 as the experiment material low-temperature competence and changes of plant hormones in the apical buds were studied. Tobacco seedlings do not respond to low-temperature signals until the sixth leaf stage. Only when the low-temperature treatment (11. 5-12. 5℃) lasted to the seventh leaf stage or longer could low-temperature affect the development of the apical buds. Before the tenth leaf, the meristem of apical buds were all in vegetative meristem phase in every treatment. But low-temperature induction influenced the changes of plant hormones in the apical buds of tobacco. During seedling stage ZRs content in the apical buds of tobacco was very low. During the process of low-temperature induction IAA content was lower than that of the controll treatment (28℃ ). The peak of IAA content of the treatments which low-temperature induction lasted to the sixth leaf stage or longer appeared in the seventh leaf stage. The content of GA3 was higher than that of the control before the eighth leaf stage. The peak of GA3 content of the treatments which low-temperature induction lasted to the seventh leaf stage appeared in the sixth to seventh leaf stage, but the peak of the control appeared in the sixth leaf stage. The peak of ABA appeared in the eighth -leaf stage, and low-temperature induction increased the content of ABA.