Department of Horticulture and Crop Science, Ohio Agricultural Research and Development Center, The Ohio State University, 1680 Madison Avenue, Wooster, Ohio 44691 USA.
Am J Bot. 2002 Dec;89(12):1859-66. doi: 10.3732/ajb.89.12.1859.
The vascular tissue of higher plants is organized into a continuous and unified system that undergoes a transition between two highly differentiated structures, the root and the shoot. This transition was studied in tomato by investigating the genetic basis of morphological variation between Lycopersicon esculentum and L. hirsutum LA407. Our analysis concentrated on morphology in stem cross sections, and we detected heritable genetic differences in an inbred backcross population having L. esculentum as the recurrent parent and LA407 as the donor parent. Inbred backcross line (IBL) 2353 contained a donor segment from chromosome 2 and retained features of the LA407 stem vascular morphology. Marker-trait analysis of vascular structure in a cross between IBL 2353 and L. esculentum showed significant (0.0001 ≤ P ≤ 0.0375) associations between markers on chromosome 2 and the size of primary vascular bundles, the shape of the vascular system, and the thickness of the secondary vascular tissue. Families with LA407 DNA for the markers on chromosome 2 had larger primary vascular bundles, more developed secondary vascular tissue, and a triangular vascular shape. These results suggest that the distal portion of chromosome 2 in LA407 contains a locus or loci affecting vascular morphology and development.
高等植物的维管组织组织被组织成一个连续统一的系统，在根和茎之间发生两种高度分化结构的转变。通过研究番茄中 Lycopersicon esculentum 和 L. hirsutum LA407 之间形态变异的遗传基础，对这种转变进行了研究。我们的分析集中在茎横切面上的形态上，并在具有 Lycopersicon esculentum 作为轮回亲本和 LA407 作为供体亲本的自交回交群体中检测到了可遗传的遗传差异。自交回交系（IBL）2353 含有来自染色体 2 的供体片段，并保留了 LA407 茎维管形态的特征。在 IBL 2353 和 Lycopersicon esculentum 之间的杂交中对维管结构的标记-性状分析表明，染色体 2 上的标记与初生维管束的大小、维管系统的形状和次生维管组织的厚度之间存在显著（0.0001≤P≤0.0375）关联。具有染色体 2 上标记的 LA407 DNA 的家系具有更大的初生维管束、更发达的次生维管组织和三角形的维管束形状。这些结果表明，LA407 染色体 2 的远端部分包含一个或多个影响维管形态和发育的基因座。
