烟草凋萎叶早期腐解液对莴苣的化感作用

Allelopathy of Inchoate Decomposing Liquid of Tobacco Withered Leaves on Lettuce

为了研究烟草凋萎叶早期腐解液及其不同组分的化感作用,以对化感物质具有高敏感性的莴苣(Lactuca sativa)为指示材料,对烟草品种K326凋萎叶早期腐解液及其分离后的各组分分别进行了化感潜力的生物测定。结果表明:1)早期腐解液及其组分随处理浓度的增大对莴苣种子萌发的抑制效应逐渐增强,且显著降低了种子萌发速率,并延长了种子的平均萌发周期;2)早期腐解液及其组分对幼苗生长和物质积累表现出"低浓度促进,高浓度抑制"的双重浓度效应;3)综合化感效应绝对强度大小表现为酸溶性组分>腐解原液>碱溶性组分>中性组分,酸溶性组分是早期腐解液产生化感抑制作用的主体,而中性和碱溶性组分在一定浓度范围内具有微弱的促进作用。实验证明烟草凋萎叶早期腐解液存在化感作用,且各组分化感作用存在较大差异。

To study the allelopathic effects of inchoate decomposing liquid of tobacco withered leaves and its compositions,lettuce（Lactuca sativa） seeds,as a sensitive species to allelopathy,were exposed to the withered leaf decomposition of flue-cured tobacco K326 and its compositions.Results showed that the germination of lettuce seeds were inhibited by tobacco withered leaf decomposition and its compositions,and the allelopathic effects became stronger as the treatment concentration increased.The germination rates were reduced,and the median germination time was prolonged.The growth and mass accumulation of lettuce seedlings was promoted at lower treatment concentrations,but inhibited at higher concentrations.Comprehensive allelopathy effect of decomposing liquid of tobacco withered leaves and its compositions followed the order of acidic compositionraw withered leaf decompositionalkaline compositionneutral composition.The acidic composition is the main contributor to inhibitive allelopathy effect in the tobacco withered leaf decomposition,whereas the neutral composition and alkaline composition could weakly facilitate the germination and growth of lettuce seeds in certain concentration range.It is indicated that inchoate decomposing liquid of tobacco withered leaves could exert allelopathic effects on lettuce,and its different compositions demonstrated different allelopathic effects.