鳢肠种子萌发及出苗条件的研究

Study on the environmental factors affecting seed germination and seedling emergence of Eclipta prostrata

通过萌发试验研究了温度、光照、pH、水势、盐分对鳢肠种子萌发以及埋土深度对其出苗的影响。结果表明:鳢肠种子萌发适宜温度为25～40℃,最适35℃;鳢肠为光敏感性种子,在光照条件下才能萌发,在黑暗中萌发受到抑制,但不同光照周期对种子萌发率没有明显影响;鳢肠种子对pH具有广泛的适应性,在pH为4～10范围内均可萌发;鳢肠种子对水势非常敏感,随着溶液水势从0下降至-0.5 MPa,萌发率从97.78%降低为4.44%;对盐分不敏感,当NaCl浓度为0.15mol.L-1时,萌发率为42.22%。表土层的鳢肠种子出苗率最高,当埋土深度大于0.5 cm时不能出苗。该研究表明:耕作将种子带入土层,可有效治理鳢肠的危害。

Experiments were conducted to evaluate the effects of temperature,light, pH, osmotic stress, salt stress and seed burial depth on seed germination and seedling emergence of Eclipta prostrata. It was found that seed germinated at a range of temperatures from 25 to 40℃. Seed germination was strongly stimulated by light, suggesting that seeds of this species are photoblastie positively. Seeds could germinate（ 93% to 100% ） at pH ranged from 4 to 10. Also seed could tolerate wide ranges of salt stress, and germination occurred even at 0.15 tool＂ L-1 （42.22%） , while it was highly sensitive to water stress, under which the germination rate would decrease from 97.78% to 4.44% with the descending of water stress from 0 to -0.5 MPa. Seeds sown on the soil surface gave the greatest seedling emergence rate（92.50% ）in plastic trays,and no seedlings emerged when seeds were buried in soil at depths of 0.5 cm. This study illustrates the role of seed burial by tillage as one important tool for the management of E. prostrata.