凋落物浸提液对杉木种子萌发及幼苗的影响

为研究杉木凋落物对杉木种子萌发及酶活性的化感作用,采用室内培养方法,以杉木种子为研究对象,设置不同浓度的杉木凋落物浸提液处理,进行杉木种子发芽试验,通过对杉木种子萌发、幼苗生长及相关酶活性的测定,比较不同杉木凋落物浸提液的处理效果。结果表明:低浓度杉木凋落物浸提液对种子萌发及幼苗生长有促进作用,以10 g·L-1的浸提液处理的种苗综合指标最好,但随着浓度的增加,杉木种子的发芽率、发芽势以及幼苗的根长、茎长、叶长和鲜重受到的抑制作用增强,其中根长对杉木凋落物浸提液的反应最敏感;随着浸提液浓度的增加,杉木幼苗的SOD活性呈下降趋势,CAT活性和POD活性呈上升趋势,MDA含量整体表现出上升趋势,其中高浓度的MDA含量与对照组差异达显著水平。综合各项指标表明,不同浓度杉木凋落物浸提液对杉木种子萌发和幼苗生长总体上起到低促高抑的作用,且高浓度杉木凋落物浸提液导致杉木幼苗体内的抗氧化酶系统功能的絮乱,可见随着杉木凋落物浸提液浓度的上升,其对杉木种苗的化感作用也逐渐增强。

Effects of Chinese fir litter extracts on the seed germination and seedlings

To study the allelopathic effect of Chinese fir litter on seed germination and enzyme activity, Chinese fir seeds were treated with different concentrations of Chinese fir litter extracts using the laboratory incubation method and Chinese fir seed germination status, growth of seedlings and related enzyme activity were measured. Results showed that:low concentration (10 g·L-1) of Chinese fir litter extracts promoted seed germination and seedling growth, and general performance, however, with the increasing concentration, seed germination percentage, the germination potential and root length, shoot length, leaf length and fresh weight of seedlings were suppressed. Among these indicators, root length is the most sensitive one reacting to Chinese fir extracts; the SOD activity decreased and the MDA, CAT and POD activity increased with the concentration growing, when it up to the maximum concentration, MDA increased significantly compared with control. In general, extracts with low concentration improved the seed germination and growth of seedlings but inhibited and led to the disorder of the antioxidant enzyme system by high concentration of extracts. In conclusion, the allelopathic effect of Chinese fir litter extracts on seedlings gradually increased with the increasing concentration.