短季棉与中熟棉生理特性的比较研究

Comparison of Physiological Char acteristics Between Short season and Mid matured Cotton (Gossypi um hirsutum L.)

短季棉 ( Gossypium hirsutum L.)与中熟棉生理特性的比较研究结果表明 ,蕾期～盛花期 ,短季棉功能叶中 SOD活性、叶绿素、全氮、钾含量和比叶重显著高于中熟品种 ,其中尤以浙 50 6最高 ,使 MDA积累延缓和减少 ,促进提高光合作用强度 ;细胞间隙 CO2 浓度显著低于中熟棉 ;短季棉光合作用强度的高峰提前在初花期 ,至盛花期仍维持在较高水平 ,促进提早并增加光合产物的积累。始絮后 ,功能叶中 MDA含量显著高于中熟棉 ,并伴随有叶绿素、全氮、钾含量的下降 。

The differences in development and physiological characteristics between short season and mid matured cotton varieties have been studied. The results showed that there was a same trend in the contents of nitrogen, potassium and chlorophyll at different growth stages. However, the contents of chlorophyll, nitrogen and potassium, SOD activity and as well as specific leaf weight of the functional leaves in short season cotton were significantly higher than that of mid matured cotton during squaring, early flowering and flowering peak stages. That was benefit to reduce the accumulation of MDA, and improve photosynthetic intensity (Pi). In addition, short season cotton reached the peak of Pi at early flowering stage, which was 30 days earlier than that of mid matured cotton, and the absolute value of Pi was higher than that of mid matured cotton, especially in the variety of Zhe506. Furthermore, it maintained relatively higher Pi until flowering peak stage. That could help enhance the accumulation of photosynthate for the boll setting and fibre development of the short season cottons. On the other hand, its stomatal conductance in functional leaf was significantly higher than that of the other varieties in this experiment. Furthermore, its MDA content was significantly increased over the mid matured cotton, at the beginning of boll opening stage, with decreasing in the contents of chlorophyll, total nitrogen and potassium and, thus, its potential productivity per plant was limited compared with mid matured cotton. Therefore, relative high plant density would be helpful to obtain high yield and good fiber quality.