根系提取物对烤烟的自毒作用研究

Study of autointoxication of tobacco root in the crude extract

为了明确连作烤烟的自毒作用,研究了烤烟根系提取物对烤烟种子萌发、烟苗干物质积累、烟苗根系生长发育及烟苗光合参数的影响。结果表明,随着根系提取物浓度的增加,烤烟种子发芽率、烟苗根系总根长、总根面积、总根体积、根尖数、气孔导度、胞间CO2浓度、蒸腾速率逐渐降低;平均根系直径,烟苗地上部干、湿重,地下部干、湿重及总干、湿重,总叶绿素含量,净光合速率均表现为先升高后降低的趋势;气孔限制值逐渐升高。烟草根系提取物对烤烟种子萌发及烟苗生长发育具有明显的抑制作用。

In order to study the autotoxicity of flue-cured tobacco in continuous cropping, effects on seed germination, seed-ling dry matter accumulation, growth of root and seedlings, and seedling photosynthesis parameters in different concentrations of crude extract of tobacco root were conducted in this paper. Results presented that with the enhancement of the concentrations of root extract, germination rate of flue-cured tobacco seeds reduced gradually;Total root length, total area of root, total vol-ume of root and root number of tobacco seedling also decreased gradually;While the average diameter of root increased first and then decreased. Dry and fresh weight of shoot and root showed the trend of increasing firstly and then decreasing;Total chloro-phyll, net photosynthetic rate increased first and then decreased;Stomatal conductance, intercellular CO2 concentration, tran-spiration rate decreased, and stomatal limiting value increased gradually. These results confirmed the inhibitory effect of root extract on tobacco seed germination and on growth of flue-cured seedlings.