玄参、川明参枯落物水浸液对烤烟的化感效应

Allelopathic Effects of Leaf-Stem Litter Aqueous Extracts of Scrophularia ningpoensis and Chuanminshen violaceum on Tobacco Growth

为探讨玄参、川明参茎叶枯落物对烟草种子萌发和幼苗生长的化感作用,选择烟草K126为研究对象,研究质量浓度为0.01, 0.02, 0.05, 0.10 mg/L的玄参、川明参茎叶枯落物水浸液处理下烟草种子的发芽率和发芽特性,以及烟草幼苗叶绿素a、叶绿素b、类胡萝卜素和抗氧化酶系统活性.结果表明,玄参水浸液低质量浓度(0.01～0.05 mg/L)处理下,种子萌发率、萌发指数显著升高,叶绿素a、叶绿素b、类胡萝卜素、丙二醛(MDA)与对照相比差异无统计学意义, 3种抗氧化酶SOD,CAT,POD活性升高,而高质量浓度(0.10 mg/L)下, MDA累积,叶绿素a、叶绿素b、类胡萝卜素质量分数显著降低,表现出对烟草"低促高抑"的化感效应;川明参在所有水浸液质量浓度(0.01～0.10 mg/L)下,种子萌发率、萌发指数、活力指数、叶绿素a、叶绿素b、类胡萝卜素质量分数升高, 3种抗氧化酶SOD,CAT,POD活性和MDA有一定降低,表现出对烟草化感正效应.

Allelopathic effect is one of the most important reasons resulting in continuous cropping obstacle. There have been relatively few studies on allelopathy between tobacco and the Chinese herbal medicinal plants Scrophularia ningpoensis and Chuanminshen violaceum . In order to investigate the allelopathic effect existing in the process of intercropping tobacco and Chinese herbal medicinal plants, this study selected the flue-cured tobacco cultivar K126 as the research object. The aqueous extract of 1-year-old leaf-stem litter of S.ningpoensis and C.violaceum (LES and LEC) at a concentration of 0.01, 0.02, 0.05 or 0.10 mg/L was used to treat the tobacco plants. The results showed that compared with the untreated control, LES at lower concentrations (0.01-0.05 mg/L) significantly raised the germination percentage of K126 and enhanced its SOD, CAT and POD activities, while no significant differences were observed in the contents of chlorophyll a, chlorophyll b, carotenoids and MDA. In contrast, LES at the highest concentration (0.10 mg/L) significantly decreased the contents of MDA, chlorophyll a, chlorophyll b and carotenoids of the tobacco plants. LEC of all concentrations exerted a positive allelopathic effect on these parameters.