低温胁迫对不同烟苗叶龄花芽分化进程的影响

Effects of low temperature stress on flower bud differentiation of different tobacco seedling leaves

以当地主推品种吉烟9号为试材,采用人工气候箱对不同叶龄烟苗进行低温诱导处理,通过体视显微镜观察花芽分化进程,且对农艺性状、现蕾数及现蕾率进行调查。结果表明:各处理的总干重均随低温处理时间的增加不断减少,CK最大,其次为低温持续3d的6叶龄烟苗;根冠比大的处理分别为低温持续3d的3叶龄烟苗及CK,最小的为低温持续9d的3叶龄烟苗;株高及有效叶数上,CK均表现最佳,而低温持续9d的6叶龄烟苗表现最差。低温处理的6叶龄烟苗最早达到现蕾期,与3叶龄烟苗及对照相比均提前4~6d。花芽分化共分6个阶段,低温处理的6叶龄烟苗花芽开始分化到结束共经历14d,而低温处理的3叶龄与CK共经历17~19d;花芽分化提前程度与低温处理持续时间成正相关,低温处理9d花芽分化提前最早,其次为6d处理,最后是3d处理;不同叶龄上,6叶龄烟苗花芽分化显著早于3叶龄烟苗。总之,早花现象最明显的是低温处理9d的6叶龄烟苗,其次是低温处理6d的6叶龄烟苗。

The local major variety Jiyan No.9 as the material, low temperature stress on tobacco seedlings with different leaf ages was induced in the artificial climate chamber. The process of flower bud differentiation was observed by stereo microscope, and the agronomic traits, bud number and bud rate were investigated. The results showed that the total dry weight of each treatment decreased with the increase of low temperature treatment time, the control was the largest, followed by the 6-leaf-aged tobacco seedlings with low temperature for 3 days. The root-to-crown ratios of the control and the 3-leaf age seedlings with the low temperature treatment for 3 days were greater than the 3-leaf age seedlings with low temperature treatment for 9 days. The control expressed the best in plant height and effective leaf number, while the 6-leaf age seedlings with the low temperature treatment for 9 days expressed the worse performance. The 6-leaf age seedlings treated with low temperature was the first to reach the bud stage, 4-6 days earlier than the 3-leaf-age seedlings and the control. The flower bud differentiation of tobacco under the stereo microscope was divided into six stages. The flower buds of the 6-leaf age seedlings with the low temperature treatment experienced 14 days from beginning to ending of differentiation, while 3-leaf age seedlings and the control experienced 17-19 days. The early days of flower bud differentiation was positively correlated with the duration of low temperature treatment. The seedlings with the low temperature treatment for 9 days was the first to reach the flower bud differentiation stage, the next for 6 days, and followed by 3 days. For different leaf age seedlings, the 6-leaf age seedlings reached the flower bud differentiation stage significantly earlier than 3-leaf age seedlings. In summary, the 6-leaf-age seedlings with the low temperature treatment for 9 days was more obviously expressed early flowering than the 6-leaf age seedlings with the low temperature treatment for 6 days in tobacco.