PP333培育烟草壮苗及其生理基础

Culturing Strong Seedings of Flue-cured Tobacco by PP333 and Physiological Basis

在烟苗生长到３～４片叶时期，用不同浓度的ＰＰ３３３浓液喷施，结果以２００×１０－６的效果最好。株高降低１．６７ｃｍ，茎粗增加０．１３ｃｍ，单株干重增加０．４５ｇ，根干重增加０．１０ｇ，根／冠比值提高，叶片叶绿素含量增加４６．６％，净光合速率提高４８．７％。处理的烟苗抗逆性也有所提高。烟苗在０～２℃低温下，原生质结构遭受破坏程度减轻，外渗物质数量减少，处理的比对照电导度减少０．１２×１０－４～０．２２×１０－４ｓ／ｍ。喷施ＰＰ３３３的烟苗叶片包含水量有所下降，但差异不大，而束缚水含量则明显提高，蒸腾强度也明显下降。

Effects of PP333 on tobacco seeding and its physiological basis were researched. The results of experiments showed that the effects of spraying 200 ×10-6 PP333 solution was the best. The PP333 Solution was sprayed on the leaves of 3￣4 leaf-stage seedlings and the results obtained were summarized as follows: stem height of seedling decreased by 1. 67 cm, stalk diameter increased by 0. 1 3 cm, dry mass per plant and root dry mass increased by 0. 45 g and 1.0 g respectively. The root-top ratio increased either.The chlorophyll content increased by 46. 6%, the net photosynthetic rate increased by 48. 7% and the resistibility of treated seedlings enhanced to some extent. Under the lower temperature condition of 1￣2℃, the structure of protoplasm slightly damaged and the quantity of exudate reduced. The electric conductivity of treated seedlings was less from 0.12×10-4 to 0. 22×10-4sm-1 than control. Although no more difference between treatment and control, the moisture content of leaves decreased to some extent. Furthermore the bound water content raised obviously and transpiration decreased obviously.