生物多样性 ›› 2018, Vol. 26 ›› Issue (11): 1158-1167.DOI: 10.17520/biods.2018213

• 研究报告 • 上一篇    下一篇

降雨年型变化及竞争对反枝苋和大豆生长的影响

姜佰文1, 李静1, 陈睿1, 鲁萍1,*(), 李琦1, 肖同玉1, 白雅梅1, 张险峰2, 李亦奇1   

  1. 1 东北农业大学资源与环境学院, 哈尔滨 150030
    2 东北农业大学实验实习与示范中心, 哈尔滨 150030
  • 收稿日期:2018-08-03 接受日期:2018-10-27 出版日期:2018-11-20 发布日期:2019-01-08
  • 通讯作者: 鲁萍
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    国家自然科学基金(31770582)、黑龙江省自然科学基金(C2017018)和东北农业大学学术骨干项目(17XG08)

Effects of annual precipitation pattern variation and different cultivation modes on the growth of Amaranthus retroflexus and Glycine max

Baiwen Jiang1, Jing Li1, Rui Chen1, Ping Lu1,*(), Qi Li1, Tongyu Xiao1, Yamei Bai1, Xianfeng Zhang2, Yiqi Li1   

  1. 1 College of Resources and Environment, Northeast Agricultural University, Harbin 150030
    2 Experiment Practice and Demonstration Center, Northeast Agricultural University, Harbin 150030
  • Received:2018-08-03 Accepted:2018-10-27 Online:2018-11-20 Published:2019-01-08
  • Contact: Lu Ping
  • About author:

    # Co-first authors

摘要:

为探索不同降雨年型及栽培方式下外来杂草与本地作物的竞争机制, 为未来全球变化背景下控制外来杂草提供理论依据, 本研究以广泛入侵东北农田生态系统的外来杂草反枝苋(Amaranthus retroflexus)和本地作物大豆(Glycine max)为研究对象, 在遮雨棚内人工模拟正常、欠缺、丰沛三种降雨年型, 采用盆栽实验的方法, 研究两种植物在单种和混种条件下的生长季节动态。结果表明, 降雨丰沛年两种植物的株高和总生物量均大于降雨正常年, 降雨欠缺年则均小于降雨正常年。生长季初期两种植物的根冠比均在降雨欠缺年最高, 说明两种植物均可通过增大根系的生物量分配, 减少地上生物量的分配来适应干旱环境。在三种降雨年型下, 混种时大豆的株高、相对生长速率及总生物量均显著小于单种大豆, 而反枝苋则相反, 尽管有时不显著, 说明种间竞争抑制大豆生长而促进反枝苋的生长, 两种植物之间的竞争是不对称竞争。总的来看, 降雨增加有利于提高大豆的竞争能力, 降雨减少有利于提高反枝苋的竞争能力, 随着生长发育的推移, 这种现象更明显。反枝苋可以在较广的降雨变化范围内保持较高的株高、相对生长速率及生物量, 这很可能是其成为全球范围成功入侵的外来杂草的重要原因之一; 干旱更有利于反枝苋入侵大豆田。

关键词: 外来杂草, 本地作物, 降雨年型, 栽培方式, 生长

Abstract:

Global climate change will alter temporal and spatial distributions of precipitation patterns. The effects of precipitation changes on crop seed germination and growth have been previously investigated, however, there has been limited research on effects of precipitation changes on how invasive weeds compete with crops. Exploring competition between exotic weeds and native crops under different annual precipitation patterns and cultivation modes will provide a theoretical basis to control alien weeds with impending changes to the global climate. In this study, we assessed how precipitation alters competitive dynamics between two plants, Amaranthus retroflexus, a widespread invasive weed in agricultural ecosystem in Northeastern China, and Glycine max, one of the most important native crops in China. We conducted pot experiments under three patterns of annual precipitation: the average annual precipitation pattern (the average total precipitation amount of growing season of the recent 30 years), the deficient annual precipitation pattern (20% lower than the average value), and the plentiful annual precipitation pattern (20% higher than the average value). The pots were placed underneath a rainout shelter, and the two plants were seeded as two plants of the same species per pot (sole species) or two plants of different species per pot (mixed species). We found that the plant height and total biomass of A. retroflexus and G. max in the average precipitation annual pattern were higher than those of deficient precipitation annual pattern, but lower than those of the abundance precipitation annual pattern. The root to shoot ratio of the two plants at the early growing season were all highest in the deficient precipitation annual pattern, indicating that both plants could adapt to the arid environment by increasing the root biomass allocation and decreasing the shoot biomass allocation. Under all the annual precipitation patterns, plant height, relative growth rate and total biomass of mixture G. max were significantly less than sole planted G. max, while A. retroflexus showed the opposite trend. These results indicate that interspecific competition significantly inhibited the growth of G. max, but promoted the growth of A. retroflexus, suggesting asymmetric competition between the species. In general, the competitive ability of G. max increased with higher precipitation, while that of A. retroflexus increased when precipitation declined. The results indicated that A. retroflexus can successfully invade G. max cropland under all three precipitation scenarios, and maintain a high plant height, relative growth rate, and biomass over a wide range of annual precipitation variation. These biological characters of A. retroflexus may allow it to become a successfully globally invasive weed, and drought may favor its invasion of G. max cropland.

Key words: exotic weed, native crop, annual precipitation pattern, cultivation mode, growth