【摘要】 以粤东地区4种菊科入侵植物三叶鬼针草(Bidens pilosa)、微甘菊(Mikania micrantha)、南美蟛蜞菊(Wedelia trilobata)、藿香蓟(Ageratum conyzoides)和1种本土植物醴肠(Eclipta prostrata)为材料,研究了种子扩散时的萌发率以及种子经历低温(15℃、湿润)和常温(25℃和25/15℃、湿润)后的萌发响应特点。结果表明:种子扩散时,三叶鬼针草、醴肠、藿香蓟种子萌发率分别为100%、98%和62%~78%,微甘菊为44%~52%,南美蟛蜞菊为2%(25℃)和86%(25/15℃);5种菊科植物种子在15℃培养期间,平均萌发率由高至低依次是三叶鬼针草(82%~91%)、微甘菊(19%~26%)、醴肠(9%~12%)、南美蟛蜞菊(0~1%)、藿香蓟(0);在25℃和25/15℃下,藿香蓟种子萌发率为35%~49%,醴肠为58%~68%,南美蟛蜞菊为4%(25℃)和55%(25/15℃)。种子快速萌发、高萌发率,以及宽泛的萌发温度需求是1年生草本入侵种的主要入侵特性。更多还原

【Abstract】 Seed germinations of five Asteraceae species including Bidens pilosa,Mikania micrantha,Wedelia trilobata,Ageratum conyzoides and Eclipta prostrata( a native species) from eastern Guangdong were studied following wet-storage at 15 ℃ for 30 days and then incubation at 25 ℃or 25 /15 ℃ for 30 days,to reveal the response of germination to temperature. The result showed that B. pilosa,E. prostrate,A. conyzoides,M. micrantha and W. trilobata seeds germinated to100%,98%,62%- 78%,44%- 52%,2%( at 25 ℃)- 86%( at 25 /15 ℃) after seed dispersal,respectively. At the first stage( at 15 ℃ under wet condition),the germination percentages of five Composite plants were 82%- 91%( B. pilosa),19%- 26%( W. trilobata),8. 7%- 12%( E. prostrata),0- 1%( W. trilobata),0%( A. conyzoides). At the second stage( at 25 ℃ and 25 /15 ℃),seeds of A. conyzoides germinated to 35% and 49%,E. prostrate to 58%- 68%,W. trilobata to 4%( at 25 ℃) and 55%( at 25 /15 ℃). Quick germination,high germination percentages,and broad temperature adaptation of germination may be important characters of these alien invasive plants.更多还原