Contribution of root cap mucilage and presence of an intact root cap in maize (Zea mays) to the reduction of soil mechanical impedance
Contribution of root cap mucilage and presence of an intact root cap in maize (Zea mays) to the reduction of soil mechanical impedance
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DOI：
10.1093/aob/mch166
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发表时间：
2004-09-01
期刊：
影响因子：
4.2
通讯作者：
Barlow, PW
中科院分区：
文献类型：
--
作者：
Iijima, M;Higuchi, T;Barlow, PW
9背景和目的土壤对根生长的阻碍作用可以通过粘液分泌和根冠边缘细胞脱落来降低。本研究的目的是量化的贡献，这两个因素对玉米根系生长在紧密的土壤。（处理I -完整）和根冠（处理D -去帽）从根尖，然后通过向完整（处理IM -完整加粘液）和去帽（处理DM -去帽加粘液）的根中添加回2穆尔粘液。根生长在松散（0.9 Mg m（-3））或紧凑（1.5 Mg m（-3））壤质砂土。还研究了在三个土壤容重（1.3，1.4和1.5毫克m（-3））根穿透阻力的影响，开盖。关键结果在治疗1，粘液可见12小时后移植到紧凑的土壤。去盖和粘胶处理既不影响。在疏松土壤中生长12 h，根伸长率和根增粗率均无显著性差异。在紧实土壤中，D、DM、I和IM处理的种子轴根系生长压力分别为0.328、0.288、0.272和0.222MPa（1.5 Mg m ~（-3））密度;结论根帽中的粘液和无粘液的完整根帽对根帽润滑作用的贡献（由去盖引起的根穿透阻力的降低百分比）分别为43%和58%。根冠的润滑效果约为30%，且不受土壤压实度的影响（对于0.52、1.20和1.59 MPa的压阻）。(C)2004年《植物学年鉴》（Annals of Botany Company）
9 Background and Aims The impedance to root growth imposed by soil can be decreased by both mucilage secretion and the sloughing of border cells from the root cap. The aim of this study is to quantify the contribution of these two factors for maize root growth in compact soil.Methods These effects were evaluated by assessing growth after removing both mucilage (treatment I - intact) and the root cap (treatment D - decapped) from the root tip, and then by adding back 2 muL of mucilage to both intact (treatment IM - intact plus mucilage) and decapped (treatment DM - decapped plus mucilage) roots. Roots were grown in either loose (0.9 Mg m(-3)) or compact (1.5 Mg m(-3)) loamy sand soils. Also examined were the effects of decapping on root penetration resistance at three soil bulk densities (1.3, 1.4 and 1.5 Mg m(-3)).Key Results In treatment 1, mucilage was visible 12 h after transplanting to the compact soil. The decapping and mucilage treatments affected neither the. root elongation nor the root widening rates when the plants were grown in loose soil for 12 h. Root growth pressures of seminal axes in D, DM, I and IM treatments were 0.328, 0.288, 0.272 and 0.222 MPa, respectively, when the roots were grown in compact soil (1.5 Mg m(-3) density; 1.59 MPa penetrometer resistance).Conclusions The contributions of mucilage and presence of the intact root cap without mucilage to the lubricating effect of root cap (percentage decrease in root penetration resistance caused by decapping) were 43% and 58%, respectively. The lubricating effect of the root cap was about 30% and unaffected by the degree of soil compaction (for penetrometer resistances of 0.52, 1.20 and 1.59 MPa). (C) 2004 Annals of Botany Company.