The exine is composed of tectum, columellae, foot layer and endexine.

花粉外壁由顶盖层、柱状层、底层及外壁内层所组成。

The pollen of the weed is the main sensibiligen of hay fever in human.

豚草花粉是人类枯草症主要致敏源。

Hay fever sufferers have a worse time when the pollen count is high.

花粉计数高时，枯草日子就更不好过了。

Hummingbirds have discovered that nectar and pollen are very nutritious.

蜂鸟发现花蜜和花粉是很有营养。

The big,empty and abortive pollen grains are abserred at the stage of uninuclear microspore.

单核期小孢子出现壁发育不良和巨大及空花粉现象。

Nectar and pollen are very nutritious.

花蜜和花粉是很有营养。

Pollen morphology of Plumbaginaceae in China.

中国白花丹科花粉形态研究.

He developed an allergy to pollen.

他花粉过敏。

Tapetum (pl. tapeta) A food-rich layer surrounding the spore mother cells in the anthers of vascular plants.

维管植物花粉囊内包围孢子母细胞富含营养物质一层结构。

The outer wall (extine) of the pollen grain is often diagnostic (see pollen) and very resistant to decay.

花粉粒外壁（花粉壁）通常为特异性并很难腐烂。

A mass of waxy pollen grains transported as a unit in many members of the Orchidaceae and Asclepiadaceae.

花粉块 Pollinium (pl. pollinia) 在许多兰科和萝藦科植物中，作为传粉单质花粉粒团。

The pollen morphology of 10 species of Scorzonera genus in the Mongolian Plateau was observed by scanning electronic microscope.

用扫描电子显微镜观察了蒙古高原鸦葱属植物10个种花粉形态。

Pollen mother cells undergo meioses through simultaneous cytokinesis and give rise to tetrads of microspores, which are tetrahedrally arranged.

花粉母细胞行减数分裂，细胞质分裂属同时型，产生小孢子四分体，为四面体形。

(2) The pantoporate pollen of P. merrilliana shows that the species has vital taxonomical and evolutionary significance in Primula.

(2) 安徽羽叶报春散孔型花粉显示其在报春花属中有重要系统意义和进化意义。

Generative nuclei The two gametic nuclei formed by the division of the generative cell in the pollen tube of angiosperms.

在被子植物花粉管中生殖细胞（应为雄原核译注）分裂成两个配子核。

The similarity of its heteropolar 3- or 6-aperturate pollen to the 3-aperturate pollen of Eudicots might result from convergent evolution.

其异极3沟或6沟型花粉与真双子叶植物3沟花粉相似是趋同演化结果。

These results indicate that callose metabolism is active and very important not only in microsporogenesis but also in microgametogenesis in rice.

营养细胞细胞质中继续积累胼胝质，花粉成熟胼胝质在小孢子形成和发育过程中功能进行了讨论。

But fed with oakery pollen,indices as above were 9. 59 days, 37. 17 days, 3. 89 days,and 0. 86 per day,respectively.

而用青杠花粉饲养，其发育历期长达9．59天，雌雄成螨寿命缩短为37．17天和3．87天，日平均产卵量仅0．86粒。

It indicated that the frequency of formation of the true pollen-derived plantletsw ere significantly low in the anther culture of B. napes.

这些结果说明在油菜花药培养中可能有一少数花粉植株形成。

As a result, this paper presents the 3D reconstruction segmentation display, and analysis results of pollen spore, chaperonin, head, cervical vertabra, tibia and carpale.

实现了花粉孢子、分子伴侣、以及头颅、颈椎、胫骨、腕骨三维重建分析测量与分割。