烟草残体腐解液及其组分的化感潜力研究

以对化感物质具有高敏感性的莴苣(Lactuca sativa)种子为指示材料，研究了烟草品种K326形成的顶、腋芽等残体腐解液的化感潜力，同时将残体腐解液(各组分)分离后分别进行化感潜力的生物测定。结果表明:1）烟草残体腐解液对莴苣种子萌发及幼苗生长具有显著的抑制作用，且表现出低促高抑的双重浓度效应；2）腐解液及其组分对种苗各部分生长的抑制强度表现为:胚根＞胚轴＞子叶；3）将烟草残体腐解液分离后进行的生物测定表明，其酸溶性组分的生长抑制作用强度＞碱溶性组分＞中性组分，在烟草残体腐解液中酸溶性组分的化感物质是形成生长抑制作用的主体，而中性及碱溶性组分中的化感物质在一定浓度范围内对生长具有促进效应。 

Allelopathic potentional of decomposing tobacco residues and its constituents

Common allelopathy bioassay system lettuce seeds (Lactuca sativa) were germinated in presence of terminal bud and axillary bud decomposition and its constituents of flue-cured tobacco K326 to evaluate the allelopathic effects. Results showed that allelopathic effects existed during decomposition of tobacco residues. Germination of lettuce seeds and seedlings growth were promoted in low concentration while inhibited by high concentrations of the residues. Each part of lettuce seedling that restrained by decomposing tobacco residues and its constituents was radicle＞hypocotyl＞cotyledon. The inhibiting intensities of three components of decomposing tobacco residues was acid soluble constituents > neutral constituents > alkali constituents. Acid allelochemicals were the main factors causing inhibition effects in decomposing tobacco residues, and certain concentrations of neutral and alkali constituents on seedling growth had some promotion effects.