关键词: 多效唑, 烟苗, 生理特性, 漂浮育苗

Abstract: In the conditions of floating seedling system, this paper studied the seedling quality changes of tobacco with spraying paclobutrazol in the period of three and a primary leaves in South Anhui. The results showed that: ① Spraying paclobutrazol had significant affection on the agronomic traits, root activity, chlorophyll content, NR activity, matters of anti-adversity and MDA content of tobacco seedlings, the effect was related to different concentration. ② Compared with CK, after sprayed paclobutrazol with 100 mg/kg and 125 mg/kg, the height of stem decreased by 45.25% and 52.94%, the dry weight of stem and leaf decreased by 37.02% and 39.45%, the diameter increased by 19.42% and 27.30%, dry weight of root increased by 19.53% and 28.62%, root activity increased by 10.59% and 14.32%, the SPAD content of chlorophyll increased by 18.12% and 27.68%, the NR activity increased by 54.51% and 73.17%, the soluble sugar content increased by 24.66% and 40.54%, the soluble protein content increased by 24.26% and 28.82%, the free proline content increased by 8.47% and 10.77%, the MDA content decreased by 7.54% and 8.70%, seedling characteristics was improved and the effect was better.

Key words: paclobutrazol, tobacco seedling, physiological characteristics, floating seedling