BACKGROUND Anoectochilus roxburghii is known for its medicinal properties, culinary interests, and ornamental applications in Asian countries. Recent studies focus mainly on its phytochemical properties and little is known about its reproductive biology, especially seed and embryo development. This study documents the major developmental events in seed and embryo development of A. roxburghii upon pollination. RESULTS Morphological and histological studies revealed that upon pollination embryo and seed development is completed in 40 days. Ovular primordia are at the megaspore mother cell stage at the time of anthesis. Embryo development proceeds after a successful fertilization. A. roxburghii has a single cell suspensor. It elongates but not extended beyond the seed coat. A distinct cell gradient is present within the embryo proper with smaller cells located towards the chalazal end of the seed. Proteins and lipids are the major storage products within the embryo proper cells. At the stage of early globular embryo, the inner seed coat has degenerated and thus a carapace is absent at maturity. A limited deposition of lignin is detected in the mature seed coat. CONCLUSIONS The seed of A. roxburghii matures rapidly. At maturity, the embryo proper has a well-differentiated apical zone with little constraints impose by the seed coat. These characters indicate adaptations to fast germination that may ensure a successful colonization in the shaded forest understory.

中文翻译：

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金线莲的胚胎学：种子和胚胎发育。

背景金线莲在亚洲国家以其药用特性、烹饪兴趣和装饰应用而闻名。最近的研究主要集中在其植物化学特性上，而对其生殖生物学，特别是种子和胚胎发育知之甚少。本研究记录了刺梨授粉后种子和胚胎发育的主要发育事件。结果 形态学和组织学研究表明，授粉后胚胎和种子发育在 40 天内完成。花期时卵子原基处于大孢子母细胞阶段。成功受精后，胚胎发育继续进行。刺梨具有单细胞悬柄。它会拉长，但不会超出种皮。胚胎内部存在明显的细胞梯度，较小的细胞位于种子的合点端。蛋白质和脂质是胚胎固有细胞内的主要储存产物。在早期球形胚阶段，内部种皮已退化，因此成熟时没有甲壳。在成熟种皮中检测到有限的木质素沉积。结论 刺梨种子成熟迅速。成熟时，胚本身具有分化良好的顶端区，几乎不受种皮的限制。这些特征表明对快速发芽的适应，这可以确保在阴凉的森林林下成功地定殖。