作　　者： ; ; ; ; ;

机构地区： 华南农业大学

出　　处： 《生态环境学报》 2013年第7期1129-1135,共7页

摘　　要： 三叶鬼针草(Bidens pilosa)是一种入侵性较强的外来杂草,现已在我国华南地区广泛蔓延。采取野外调查与室内实验相结合的方法,研究了三叶鬼针草与土著种鬼针草(Bidens bipinnata)的繁殖特征与种子萌发特性。结果表明:与土著种鬼针草相比,三叶鬼针草的分枝能力强,分枝数量多,并能够产生数量更高、质量更轻的种子。三叶鬼针草、鬼针草的最适萌发温度分别为20～30℃、10～25℃,其萌发率均高达92.00%以上,高温(30～40℃)不利于两种杂草种子的萌发,但土著种受到的抑制作用更强。两种杂草种子均在全光处理下获得最高萌发率,除全黑暗处理外,环境光强变化对三叶鬼针草的种子萌发影响不明显,但25%弱光导致鬼针草的萌发率显著下降。轻度干旱(ρ(PEG)≤0.10 g.mL-1)对两种杂草种子的萌发影响不大,中度干旱(ρ(PEG)=0.15 g.mL-1)能够降低其种子萌发率,但相对而言,三叶鬼针草的萌发率降幅较小。两种杂草种子的萌发对pH的适应范围较广,只有pH 2.0的强酸性溶液才造成其种子萌发率显著下降。外界过高的N、P养分对两种杂草种子的萌发均产生不利影响,尤其是N素过高对土著种鬼针草种子萌发的抑制作用更强。掩埋处理能够抑制两种杂草种子的萌发,当埋藏深度达3.0 cm时,所有的种子均不能正常萌发与出苗,但在土壤表面,三叶鬼针草的萌发势要显著高于鬼针草。 Bidens pilosa is one of the noxious alien Asteraceae weeds with strong invasiveness, and is spreading widely in Southern China at present. We studied the reproductive traits and seed germination characteristics of invasive B. pilosa and native B. bipinnata by combining field investigations with laboratory experiments. The results showed that compared to native species, B. pilosa had higher ramification ability and branch numbers. One single mature plant could produce more than 13 thousands of seeds with smaller mass. Seed germinations of the two weed species were affected by environment factors. The optimum germination temperature for B. pilosa and B. bipinnata was 20-30 ℃ and 10-25 ℃, respectively. Both species had high germination percentages, above 92.00%. High temperature （30-40 ℃） caused harms to seed germination of the two species, but the inhibition effect of high temperature on native B. bipinnata was severer than that of B. pilosa. The seeds of two weeds reached maximum germination at full irradiance, and the changes of ambient light had no effects on B. pilosa germination except in the dark, but the germination of B. bipinnata was significantly decreased at 25%irradiance. Light drought （ρ（PEG）≤0.10 g？mL-1） had no significant effects on germination of the two weed species while moderate drought （ρ（PEG）=0.15 g？mL-1） could reduce their germination percentage, but the negative effect on B. pilosa was less than that of B. bipinnata. Both weed species germinated in a wide range of pH （3.0-7.0） and only pH 2.0 caused the seed germination to decrease significantly. High concentration of N and P nutrients had negative influences on the germination of both weed species, and excessive N concentration had more inhibitory effect on native B. bipinnata than on B. pilosa. Germination of both species could be inhibited by the buried treatment and no seedlings emerged when seeds were sowed 3.0 cm deep. But on the soil surface, germination rate of B. pilosa was significantly higher t

关 键 词： 生物入侵 三叶鬼针草 鬼针草 种子萌发

领　　域： [生物学]