Root cap removal increases root penetration resistance in maize (Zea mays L.)
Root cap removal increases root penetration resistance in maize (Zea mays L.)
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DOI：
10.1093/jxb/erg226
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发表时间：
2003-09-01
影响因子：
6.9
通讯作者：
Bengough, AG
中科院分区：
文献类型：
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作者：
Iijima, M;Higuchi, T;Bengough, AG
根冠通过粘稠的粘液分泌和外部细胞的脱落来帮助根部通过土壤。对去顶玉米(Zea Mays L.cv.)根的穿透阻力进行了研究。在松散(干容重1.0g cm(-3)，渗透阻力0.06 Mpa)和紧实土壤(1.4g cm(-3)，渗透阻力1.0 Mpa)条件下，评价盖帽对降低根系生长阻力的作用。在疏松土壤中生长时，去根和完整根的伸长率和直径相同。而在紧实土壤中，去根的伸长率仅为完整根的一半左右，而直径却增加了30%。在紧实土壤中生长时，完整和去掉精子轴的根系穿透阻力分别为0.31和0.52 Mpa。这些结果表明，根冠的存在在很大程度上减轻了对根渗透的机械阻抗，并使根在压实土壤中生长得更快。
The root cap assists the passage of the root through soil by means of its slimy mucilage secretion and by the sloughing of its outer cells. The root penetration resistance of decapped primary roots of maize (Zea mays L. cv. Mephisto) was compared with that of intact roots in loose (dry bulk density 1.0 g cm(-3); penetration resistance 0.06 MPa) and compact soil (1.4 g cm(-3); penetration resistance 1.0 MPa), to evaluate the contribution of the cap to decreasing the impedance to root growth. Root elongation rate and diameter were the same for decapped and intact roots when the plants were grown in loose soil. In compacted soil, however, the elongation rate of decapped roots was only about half that of intact roots, whilst the diameter was 30% larger. Root penetration resistances of intact and decapped seminal axis were 0.31 and 0.52 MPa, respectively, when the roots were grown in compacted soil. These results indicated that the presence of a root cap alleviates much of the mechanical impedance to root penetration, and enables roots to grow faster in compacted soils.