A novel mold was devised to embed microcores extracted from stems of trees in epoxy resin, which has been widely used for optical and electron microscopic analysis of xylem formation. The embedding mold of a tight cylindrical shaped tube was designed to avoid displacement of microcores from the right position during the process of resin embedding. Microcores of a ring-porous hardwood species, Quercus crispula, with higher wood density and much larger differentiating vessel elements laid down on the boundary between the current xylem and the previous one, which generally cause difficulty in thin sectioning and breaks in sections, respectively, were embedded in the cylindrical molds full of epoxy resin. Locations of the three principal planes of wood anatomy could be determined in cylindrical resin-embedded microcores as follows: the transverse plane could be found on their side of cylinder, the radial one was vertical to the transverse, and the tangential ones were their circular ends of cylinder. The present embedding mold, therefore, can provide all three principal sections for microscopic wood anatomy from the side or ends of the same cylindrical microcore in principle. To confirm the usefulness of the resin-embedded microcores, we examined the differentiation of vessel elements during the period of earlywood formation on their transverse sections under microscopes, consequently could observe cell division in the cambial zone and sequential stages of vessel element differentiation, including cell expansion and deposition of the secondary cell wall. The present embedding mold for epoxy resin is simple but highly useful and innovative for a wide range of applications of microcores in microscopy for studies on tree-ring formation.

设计了一种新型模具，将从树木茎中提取的微核嵌入环氧树脂，已广泛用于木质部形成的光学和电子显微分析。紧密圆柱形管的嵌入模具旨在避免在树脂嵌入过程中微芯从正确位置移位。一种环孔硬木的微核，Quercuscrissula，具有更高的木材密度和更大的差异容器元件放置在当前木质部和前一个木质部之间的边界上，这通常分别导致薄切片困难和断面，分别被嵌入充满环氧树脂的圆柱形模具中。在圆柱形树脂嵌入微芯中，木材解剖学的三个主平面的位置可以确定如下：横向平面位于圆柱体的侧面，径向平面与横向垂直，切线平面为其圆形端气缸。因此，本嵌入模具原则上可以从同一圆柱形微芯的侧面或末端提供用于微观木材解剖结构的所有三个主要部分。为了确认树脂嵌入微核的有用性，我们在显微镜下观察了早材形成期间血管元件的横切面的分化，从而可以观察到形成层区域的细胞分裂和血管元件分化的连续阶段，包括细胞扩张和次生细胞壁的沉积。目前的环氧树脂嵌入模具简单但非常有用和创新，适用于微芯在显微镜中的广泛应用，用于研究树木年轮的形成。