Intermittent pollen-tube growth in pistils of alders (Alnus).
Intermittent pollen-tube growth in pistils of alders (Alnus).
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DOI：
10.1073/pnas.0503081102
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发表时间：
2005-06
影响因子：
11.1
通讯作者：
A. Sogo;H. Tobe
中科院分区：
文献类型：
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作者：
A. Sogo;H. Tobe
在赤杨，授粉后约8周受精，花粉管(雄配子体)分四个阶段间歇生长，与子房及其胚珠的发育密切相关。花粉管在花柱、子房室和合点(胚珠)停止生长，然后到达胚囊受精。当子房发育成胚珠原基时，许多花粉管在柱头上萌发，少数花粉管到达花柱，并保持约7周。此后，单管恢复生长；在卵巢室的上部空间短暂停留，当它发育成两核胚囊时，它到达两个胚珠中较老的一个。除了最后一步，管子从合点生长到胚囊(雌配子体)，雌蕊中的花粉管不需要八核成熟胚囊来引导。虽然间歇性的花粉管生长在从多个花粉管中选择单个花粉管和从两个胚珠中选择一个花粉管的过程中起着重要的作用，但它的检测为研究花粉管引导的机制提供了线索。
In alders, where fertilization occurs approximately 8 weeks after pollination, the pollen tube (male gametophyte) grows intermittently in four steps in close association with the development of the ovary and its ovules. Pollen tubes stop growing in the style, at the ovarian locule, and at the chalaza (ovule), before reaching an embryo sac for fertilization. At the stage when the ovary develops an ovule primordium in each of the two locules, many pollen tubes germinate on the stigma, and a few of them reach the style, where they remain for approximately 7 weeks. Thereafter, a single tube resumes growing; with a short stop in the upper space of the ovarian locule, it reaches the older of the two ovules when it has developed a two-nucleate embryo sac. Except in the last step, where the tube grows from the chalaza to an embryo sac (female gametophyte), an eight-nucleate mature embryo sac is not necessary for pollen-tube guidance in the pistil. Although the intermittent pollen-tube growth appears to play an important role in the selection of a single pollen tube from many and one ovule from two, its detection provides insight into the study of the mechanism of pollen-tube guidance.