Pollen Organ Telangiopsis sp. of Late Devonian Seed Plant and Associated Vegetative Frond.
Pollen Organ Telangiopsis sp. of Late Devonian Seed Plant and Associated Vegetative Frond.
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花粉器官Telangiopsis sp。泥盆纪晚期植物和相关的营养叶。
DOI：
10.1371/journal.pone.0147984
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Guo Y
中科院分区：
文献类型：
--
作者：
Wang DM;Meng MC;Guo Y
花粉器官 Telangiopsis sp.，与营养叶相关但不附着，是从中国安徽省东至县上泥盆统（法门纪）五通组采集的。具有末端花粉器官的能育轴二歧2-4次，并且可能由碎片小羽片近端附着。花粉器官是合囊的，长在短茎的顶部。孢子囊呈放射状对称，每个孢子囊由 4-8 个在基部融合的细长小孢子囊组成。小孢子囊具有纵向开裂线并显示锥形顶端。相关的茎有刺，并有营养叶，在基部分叉一次。叶轴具有交替排列的一序羽片。小羽片交替生出，平坦，高度解剖，同样二歧2-3次。晚泥盆世种子植物之间的比较认识到带有末端花粉器官的可育叶/轴中的几种分枝模式。毛毛藻属 sp.证实晚泥盆世花粉器官通常与基部融合的小孢子囊是合胞体。有人认为，花粉器官径向对称性和双边对称性的进化分歧可能发生在法门纪，当时最早的种子植物进化出扁平状，有时进化出层状小羽片。
Pollen organ Telangiopsis sp., associated with but not attached to vegetative fronds, has been collected from the Upper Devonian (Famennian) Wutong Formation, Dongzhi County, Anhui Province, China. Fertile axes with terminal pollen organs are dichotomous for 2–4 times and may be proximally attached by fragmentary pinnules. Pollen organs are synangiate and borne on the top of a short stalk. Synangia are radial in symmetry and each consists of 4–8 elongate microsporangia fused at base. Microsporangia have a longitudinal dehiscence line and show a tapered apex. The associated stem is spiny and bears a vegetative frond which bifurcates once at the basalmost part. Frond rachises possess one order of pinna arranged alternately. Pinnules are borne alternately, planate, highly dissected, and equally dichotomous for 2–3 times. Comparisons among Late Devonian seed plants recognize several branching patterns in the fertile fronds/axes bearing terminal pollen organs. Telangiopsis sp. reinforces that the Late Devonian pollen organs are synangiate usually with basally fused microsporangia. It is suggested that the evolutionary divergence of radial and bilateral symmetries of pollen organs may have occurred in the Famennian, when the earliest seed plants evolved planate and sometimes laminate pinnules.