Bajwa Ali Ahsan, Chauhan Bhagirath Singh, Adkins Steve
School of Agriculture and Food Sciences, The University of Queensland, Gatton, Queensland, 4343, Australia.
The Centre for Plant Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Gatton, Queensland, 4343, Australia.
Environ Sci Pollut Res Int. 2017 Jul;24(19):16186-16194. doi: 10.1007/s11356-017-9176-1. Epub 2017 May 24.
Parthenium weed is a problematic invasive species in several countries around the world. Although it is considered to be a highly invasive species within Australia, not all biotypes of parthenium weed exhibit the same ability in regard to aggressive colonization and distribution. Differences among biotypes, particularly in regard to environmental ranges as a possible basis for this variation, have not always been elucidated. To determine whether drought tolerance could be a factor in biotype demographics, we quantified the biological responses of two Australian parthenium weed biotypes known to differ in invasive ability Clermont ("high") and Toogoolawah ("low") to 100, 75 and 50% of soil water holding capacity (WHC). The Clermont biotype had greater vegetative growth, seed production and chlorophyll content than Toogoolawah, across all moisture levels. Net photosynthesis, stomatal conductance, internal CO concentration, seed production per plant, 1000 seed weight and subsequent germination percentage were also higher for Clermont than for Toogoolawah and were maximum at 75% WHC. Clermont plants also had higher total soluble sugar, phenolics and free proline content than Toogoolawah, and a significant increase in the levels of all of these biochemicals was observed at 50% WHC. In conclusion, Clermont grew and reproduced better than Toogoolawah across all moisture regimes consistent of enhanced invasive ability of this biotype. Overall, the ability of parthenium weed to maintain good growth, physiology and seed production under moisture stress may enable it to colonize a wide range of Australian environments.
银胶菊是世界上多个国家的一种有问题的入侵物种。尽管它在澳大利亚被认为是一种高度入侵性物种，但并非所有银胶菊生物型在积极定殖和分布方面都表现出相同的能力。生物型之间的差异，特别是关于环境范围作为这种变异的可能基础，尚未完全阐明。为了确定耐旱性是否可能是生物型种群统计学的一个因素，我们量化了两种已知入侵能力不同的澳大利亚银胶菊生物型——克莱蒙特（“高”）和图古拉瓦（“低”）对土壤持水量（WHC）的100%、75%和50%的生物学响应。在所有湿度水平下，克莱蒙特生物型的营养生长、种子产量和叶绿素含量均高于图古拉瓦。克莱蒙特的净光合作用、气孔导度、胞间CO浓度、单株种子产量、千粒重和随后的发芽率也高于图古拉瓦，且在75%WHC时最大。克莱蒙特植株的总可溶性糖、酚类和游离脯氨酸含量也高于图古拉瓦，并且在50%WHC时观察到所有这些生化物质的水平显著增加。总之，在所有湿度条件下，克莱蒙特的生长和繁殖都比图古拉瓦好，这与该生物型增强的入侵能力一致。总体而言，银胶菊在水分胁迫下保持良好生长、生理和种子生产的能力可能使其能够在澳大利亚的广泛环境中定殖。
