入侵植物蒙古苍耳种子萌发对环境因子的响应

Responses of the seed germination of invasive plants Xanthium mongolicum to environmental factors

本研究通过对室内受控条件下入侵植物蒙古苍耳种子对各环境因子(温度、光照、土壤水分、土壤盐分及土壤酸碱度)处理下种子萌发率及萌发指数的比较分析,探讨了蒙古苍耳种子萌发对于环境因子的响应。结果表明:在温度为10-35℃时,种子均可萌发,而其适宜温度为20-30℃。光照对种子萌发没有显著影响;在相对湿度为30%-100%的土壤环境中,超过70%的种子可以正常萌发,表现出其对土壤水分有极宽泛的耐受幅度;随土壤盐分浓度的升高,其种子萌发率呈下降趋势,但在280 mmol/L的高浓度土壤Na Cl环境中,可以萌发的种子仍达到17%;在土壤环境为pH 4-10时,其种子萌发率高达70%以上,表现出对土壤酸碱度有较强的耐受性。这表明蒙古苍耳种子对各环境因子都有极强的耐受性,在种子萌发阶段对各环境因子都有较宽泛的耐受幅度,高原山区、荒漠、盆地和盐碱地等复杂多变的环境都是其种子萌发的适宜生境,这为预测蒙古苍耳的适生区域及制订有效的防除策略提供了科学依据。

We studied the responses of Xanthium mongolicum seed germination to the environmental factors： temperature, light, soil moisture, soil salinity, and soil pH. The results showed that： The seeds could germinate at 10-35 ℃, and the optimal temperature was 20-30 ℃. The germination percentage was higher than 70% under both light and dark conditions, suggesting that light had no significant effect on seed germination of X. mongolicum. Many seeds germinated at 30%-100% relative soil humidity, suggesting that X. mongolicum seeds also had a strong tolerance to soil moisture. The germination rates decreased with the increase of soil salinity. However, at a high concentration soil environment of 280 mmol/L NaCl, the seed germination could still reach 17%. Many seeds were able to germinate in a wide range of soil pH values, and the germination rates was above 70% with soil pH 4-10. These results show that X. mongolicum seed was highly tolerant to environmental fluctuations, X. mongolicum have strong adaptability to temperature, light, soil moisture, soil salinity and soil pH in the germination stage. Those results suggest that X. mongolicum seeds can germinate energetically in a wide variety of drastically different habitats such as high-altitude mountains, arid desert, basin desert and alkali soil. The data obtained from this study can help predict its potential spread area and facilitate the development of effective weed control programs.