入侵植物银胶菊对不同氮、磷水平的繁殖适应性

Reproductive Adaptability of the Invasive Weed Parthenium hysterophorus L.under Different Nitrogen and Phosphorus Levels

通过模拟野外生境,研究了入侵植物银胶菊(Parthenium hysterophorus L.)在不同氮、磷养分水平下的繁殖特征,探讨其对土壤养分增加的繁殖适应性及繁殖能力。结果表明:在一定范围内,随氮水平的增加,银胶菊分枝数、头状花序数、繁殖器官的生物量及其比例、结实率等显著增加;对于磷养分来说,仅株高和种子千粒重明显增加,其余参数未见明显增加。银胶菊主要通过提高种子产量适应氮养分丰富的生境,而通过提高种子质量才能适应磷养分丰富的生境。土壤氮、磷养分的增加,提高了其繁殖能力,使其具有根据环境养分调节繁殖特性的能力,实现对不同养分资源生境的入侵。

Parthenium hysterophorus L.is an aggressive herbaceous weed from the Asteraceae family.It invades disturbed environments of different nutrient levels such as arable land,waste land,and roadside.The reproductive adaptability of this weed to different nitrogen and phosphorus levels was studied.The results showed that SPAD value,branch and inflorescence number,total biomass,flower mass and its ratio,and seed set increased with increasing nitrogen levels.While height and 1000-seed weight increased with increasing phosphorus levels,other parameters showed no increase.This weed acclimated to a wide range of nitrogen environments through increased seed production,which was achieved by enhancing branch and inflorescence number,flower mass and its ratio,as well as seed set,and to phosphorous rich environments through improved seed quality.The addition of nitrogen and phosphorus in soil could,therefore,promote the reproductive ability of Parthenium hysterophorus,and increase its invasiveness in nitrogen and phosphorus rich environments.