摘要:胜红蓟为我国南部低海拔区域农田和果园恶性杂草。为揭示胜红蓟环境适应规律、明确其危害性，评价和分析了胜红蓟种子萌发对光照、温度、pH、盐度、渗透势等环境因子的响应特征。结果表明：胜红蓟种子在10-30℃内均能萌发，最适萌发温度为20℃，交替温度处理可提高种子的萌发率。胜红蓟种子萌发对光照敏感，无光照处理种子不萌发。土壤相对湿度在50%-100%范围内，种子出苗率均高于55%，最适相对湿度为70%。胜红蓟种子仅能在土壤表面萌发，1 cm的播种深度完全抑制种子萌发。pH值在5-10之间，种子萌发率高于85%，最适pH值为7。NaCl浓度在0-80 mmol/L以内种子萌发率超过88%，浓度为160 mmol/L时萌发率接近30%。渗透势在-0.40-0 MPa以内种子萌发率高于70%，渗透势为-0.6 MPa时种子不能萌发。由此可见，胜红蓟种子萌发具有广阔的环境适生范围，对农作物具有较强的早期危害性。



Abstract:Ageratum conyzoides is a detrimental weed in the low-altitude farmland and orchards of south China. To elucidate the adaptive ability of A. conyzoides in the environment and its perniciousness, studies were conducted to evaluate the influence of different environmental factors, including light, temperature, pH, humidity, and osmotic potential, on seed germination and seeding emergence of Ageratum conyzoides. The results showed that: (1) seeds could germinate from 10 ℃ to 30 ℃ with the optimum temperature being 20 ℃. Additionally, alternating temperature could increase the rate of seed germination. (2) Seeds of A. conyzoides were sensitive to light, and it was difficult for seeds to germinate without light. (3) The rate of seed germination was higher than 55% when the soil relative humidity was in the range of 50%-100%, with the optimum relative humidity being 70%. (4) Seeds could germinate at the soil surface, and emergence was inhibited if seeding depth reached 1 cm. (5) The seed germination rate reached 85% when pH was in the range of 5-10, with the optimum pH being 7. (5) When the concentration of NaCl was at 0-80 mmol/L, seed germination rate was above 88%, while germination was 30% at salinity level of 160 mmol/L. (6) When osmotic potential was -0.40-0 MPa, the germination rate reached 70%, but no germination occurred at osmotic potentials of -0.6 Mpa. Therefore, it could be inferred that A. conyzoides showed strong adaptiveness to the different environments. As such, it could cause early damage to crops.





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