Di Iorio Antonino, Lasserre Bruno, Scippa Gabriella S, Chiatante Donato
Department of Chemical and Environmental Sciences, University of Insubria, Via Valleggio 11, 22100 Como, Italy.
Tree Physiol. 2007 Mar;27(3):407-12. doi: 10.1093/treephys/27.3.407.
We investigated changes in the pattern of secondary thickening along first-order lateral roots of Quercus cerris L. (turkey oak), a dominant species in the mixed forests of the Mediterranean basin. The eccentricity of radial growth was analyzed relative to the gravimetric center of the root, a measure that is unaffected by year-to-year variation in growth ring width. In cross sections collected at the taproot-lateral root junction, radial growth was greatest on the upper side of the root. However, at a distance of 10 cm from the taproot-lateral root junction, radial growth was greatest on the lower side of the root. With increasing distance from the taproot-lateral root junction, the direction of the vector of radial growth eccentricity changed in an anti-clockwise direction as viewed from the distal face of the root cross section. These findings applied to all lateral roots of the studied root system, irrespective of root size, depth of origin and axial growth direction. Ring analysis indicated that most first-order lateral roots grew to a length of 1 m in the first year.
我们研究了地中海盆地混交林中的优势树种土耳其栎（Quercus cerris L.）一级侧根次生增厚模式的变化。相对于根的重心分析径向生长的偏心率，该测量不受年轮宽度逐年变化的影响。在主根与侧根交界处采集的横切面中，根的上侧径向生长最大。然而，在距主根与侧根交界处10厘米处，根的下侧径向生长最大。从根横切面的远端面看，随着距主根与侧根交界处距离的增加，径向生长偏心率矢量的方向沿逆时针方向变化。这些发现适用于所研究根系的所有侧根，无论根的大小、起源深度和轴向生长方向如何。年轮分析表明，大多数一级侧根在第一年生长到1米长。
