加拿大一枝黄花(Solidago canadensis L.)水浸提液对小麦的化感作用及机制

Allelopathic effect and mechanism of extract solution from Solidago canadensis L.on wheat( Triticum aestivum)

为了阐明加拿大一枝黄花(Solidago canadensis L.)对小麦的化感作用机制,研究了加拿大一枝黄花新鲜茎叶的水浸提液对小麦(Triticum aestivum)种子萌发和幼苗生长的影响,以及对小麦种子中α-淀粉酶活性、叶片中脂质过氧化作用及根系活力的影响。整个试验在完全随机情况下进行,一组质量浓度0.025、0.05和0.1 g·mL-1水浸提液用于对小麦化感作用的研究,在此基础上,设置另一组质量浓度0.01、0.02和0.03 g·mL-1水浸提液用于作用机制随水浸提液处理7和14 d时的变化研究,均用蒸馏水作空白对照。结果表明:在水浸提液质量浓度为0.025、0.05和0.10 g·mL-1时,加拿大一枝黄花水浸提液对小麦种子萌发和幼苗生长表现出很强的抑制作用,而且抑制强度随水浸提液质量浓度的增加而增强。水浸提液抑制小麦种子α-淀粉酶的活性,0.03 g·mL-1时达到显著水平(P<0.05)。水浸提液处理小麦7 d后,小麦叶片中SOD、POD和CAT活性均受到抑制,MDA含量显著升高,作用强度随水浸提液质量浓度的增加而增强。处理14 d后,SOD与CAT活性呈现出不规律性波动,MDA含量仍呈上升趋势,总体水平低于7 d时的试验结果;POD活性呈下降趋势,但与对照无显著差异,总体水平高于7 d时的试验结果。水浸提液处理后,小麦根系活力升高,随着处理时间延长,根系活力有所下降。结论:加拿大一枝黄花水浸提液对小麦种子萌发的抑制作用与α-淀粉酶活性的变化有关,对小麦幼苗生长的抑制作用与脂质过氧化作用和根系活力的变化有关。

To clarify allelopathic potential and its preliminary mechanism of Solidago canadensis L. on wheat （Triticum aestivum）, allelopathic effects of fresh S. canadensis stems and leaves extract solution on seed germination and seedling growth were assessed in wheat. Subsequently, study on α-amylase activity,lipid peroxidation and root activity of wheat treated by S. canadensis extract solution was carried out. The experiments were carried out under completely randomized design with 4 replications and 4 treatments （0.025,0.05 and 0.1 g. mL-1 extract solutions for allelopathy, and based on it ,0.01,0.02 and 0.03 g· mL-1 extract solutions for mechanism after 7 and 14 d treatments,and water as control,respectively）. The results showed that extract solutions from the concentration of 0.025,0.05 and 0.1 g· mL-1 of S. canadensis inhibited the seed germination and seedling growth of wheat significantly, and the inhibitory intensity increased with enhancing extract concentration. S. canadensis extract inhibited α-amylase activity and reached significant level at the concentration of 0.03 g·mL-1 （P〈0.05）. After 7 d treatment, all of SOD, POD, CAT activities were inhibited,while MDA content was increased remarkably. The inhibitory intensity and MDA content increased with enhancing extract concentration. After 14 d treatment, SOD and CAT activities changed erratically,while MDA content was still on the rise, and the levels were lower than 7 d results;POD activity reduced but not significantly and the level was higher than 7 d results. Wheat root activity rose with the concentration of S. canadensis extract. As the treating time was longer, root activity reduced. This study supported the assumption that the changes of or-amylase activity and lipid peroxidation, root activity were associated with the inhibitory effects on wheat seed germination and seedling growth of S. canadensis extracts, respectively.