Department of Life Science and Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
Department of Agro-environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan.
Sci Rep. 2018 Nov 6;8(1):16417. doi: 10.1038/s41598-018-34772-2.
Positions of leaves along a stem usually adhere to a genetically determined, species-specific pattern known as a leaf phyllotaxis. We investigated whether the arrangement of lateral secondary veins along primary midveins adhered to a species-specific pattern that resembled an alternate or opposite phyllotaxis. We analyzed the venation of temperate dicotyledonous species from different taxonomic groups and chose 18 woody and 12 herbaceous species that have reticulated leaf venation. The arrangement of the lateral veins was neither alternate nor opposite for any of the species. Lateral vein arrangements were instead mixtures of symmetric and asymmetric patterns. Our results show that lateral vein arrangements are related neither to stem-level leaf phyllotaxis (alternate vs. opposite) nor to life form (woody vs. herbaceous). Our results are therefore generally consistent with the canalization hypothesis that the locations of lateral veins are not completely specified genetically prior to leaf formation.
叶片在茎上的着生位置通常遵循一种遗传决定的、物种特有的模式，称为叶序。我们研究了侧生二级脉沿主中脉的排列是否遵循一种类似于互生或对生叶序的物种特异性模式。我们分析了来自不同分类群的温带双子叶植物物种的脉序，并选择了 18 种木本和 12 种草本植物，它们具有网状叶脉序。对于任何一种植物，侧脉的排列都不是互生的，也不是对生的。侧脉的排列方式相反，是对称和不对称模式的混合。我们的结果表明，侧脉的排列方式既与茎生叶序（互生对生）无关，也与生活型（木本草本）无关。因此，我们的结果通常与通道假说一致，即侧脉的位置在叶片形成之前并非完全由遗传决定。
