Root foraging capacity depends on root system architecture and ontogeny in seedlings of three Andean Chenopodium species
Root foraging capacity depends on root system architecture and ontogeny in seedlings of three Andean Chenopodium species
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DOI：
10.1007/s11104-014-2105-x
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发表时间：
2014-07-01
期刊：
影响因子：
4.9
通讯作者：
Joffre, Richard
中科院分区：
文献类型：
--
作者：
Alvarez-Flores, Ricardo;Winkel, Thierry;Joffre, Richard
根系结构的形态和个体发生变异具有生态学意义，特别是在资源匮乏的生境中，土壤生根对幼苗的形成和水分和养分的吸收都至关重要。为了评估不同农业生态背景下的差异，本研究比较了安第斯山脉地区hircinum Chenopodium、pallidicaule Chenopodium和两种生态型（干湿生境）藜麦Chenopodium quinoa的根构型和生根模式。在控制水分和养分利用率的条件下，将幼苗生长在根茎中。在萌发后6周内测定根分枝和伸长动态，并在试验结束时测定叶面积、地上和地下生物量和比根长度。尽管地上生物量差异较大，但所有种群均表现出相似的人字形根系。干旱生境藜麦根系性状值普遍最高，主根伸长快，根系粗，根节长，根系总长度高，根系增殖深。尽管它们的农业生态背景不同，但所研究的藜足类动物显示出相似的根系拓扑结构。然而，从发育早期开始，它们就表现出差异的根系觅食模式，表现为两个极端：干旱生境奎奴亚藜快速而旺盛的深层根系，以及适应浅土和高海拔生境的白斑藜浅而细的根系。
Morphological and ontogenetic variation in root system architecture holds ecological significance, particularly in low-resource habitats where soil rooting is critical for both seedling establishment and water and nutrient uptake. To assess this variation under contrasted agroecological backgrounds, root architecture and rooting patterns were compared in Andean populations of Chenopodium hircinum, Chenopodium pallidicaule and two ecotypes (wet- and dry-habitat) of Chenopodium quinoa.Seedlings were grown in rhizotrons under controlled water and nutrient availability. Root branching and elongation dynamics were characterized during 6 weeks after germination, while leaf area, above and below-ground biomass, and specific root length were determined at the end of the experiment.Despite large differences in aboveground biomass, all populations showed similar herringbone root systems. The dry-habitat C. quinoa had generally the highest root trait values, with fast taproot elongation, thick roots and long root segments resulting in high total root length and deep root proliferation.Irrespective of their contrasting agroecological background, the studied chenopods displayed a similar root system topology. However, from very early development stages, they showed differential root foraging patterns with two extremes: fast and vigourous rooting at depth in the dry-habitat C. quinoa, and shallow and thin root system in C. pallidicaule adapted to shallow-soil and high-altitude habitats.