湘南烤烟生理特性对生育前期烟田水分的响应

Physiological Characteristics of Flue-cured Tobacco Responding to Soil Moisture Content at Early Growth Stage in South Hunan

采用大田控水试验,分别将烟株生育前期烟田供水量控制为常规供水量的70%,50%和30%,研究了湘南烤烟生理特性对烟田不同水分条件的响应。结果表明:在按常规供水量的70%和50%供水条件下,烟株叶片发育、根系发育及综合长势明显优于对照;成熟期各处理的叶片超氧阴离子和过氧化氢均低于对照,叶绿素含量均高于对照;初始荧光(F0)略高于对照,而最大光化学效率(Fv/Fm)略低于对照。控水处理叶片的"日灼烟"现象显著减少,说明在湘南烟区气候条件下适当控制生育前期烟田的含水率有利于烟株的壮根壮苗和生长发育,可作为防控该烟区烟叶"高温逼熟"现象的有效措施之一。

The physiological characteristics of flue-cured tobacco responding to soil moisture content at early growth stage in South Hunan was studied with field experiments, when water supply was controlled at 70%, 50% and 30% of the normal level. The results showed that the leaf development, root development and general growth vigor of the plants watered at 70~/; and 50% of the normal level were much better than those of the control. For all the treatments, the superoxide anion and hydrogen peroxide in leaves were lower, and the chlorophyll contents were higher comparing with the control; initial fluorescence （F0） was slightly higher, while the maximum photochemical efficiency （Fv/Fm） was slightly lower than that of the control. The phenomenon of sunburn in leaves of all the treatments was much less than that of the control, which indicated that appropriate control of water supply at the early growth stage was beneficial to the development and growth of vigorous root systems and seedlings of tobacco plants, it could he used as an efficient measure to prevent tobacco from ＂heat-forced maturity＂.