The timetable for development of maternal tissues sets the stage for male genomic selection in Betula pendula (Betilaceae)
The timetable for development of maternal tissues sets the stage for male genomic selection in Betula pendula (Betilaceae)
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母体组织的发育时间表为白桦（Betilaceae）雄性基因组选择奠定了基础
DOI：
10.1002/j.1537-2197.1996.tb12782.x
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发表时间：
1996
影响因子：
3
通讯作者：
M. Fredrikson
中科院分区：
文献类型：
--
作者：
Å. Dahl;M. Fredrikson
本文研究了白桦（Betulaeriaau）母体组织发育顺序对雄配子选择潜力的影响，并确定了两个胚珠中一个胚珠的固定败育时间。我们使用扫描电子显微镜、共聚焦激光扫描显微镜和蓝光显微镜。柱头在整个雄花期内保持新鲜，也可能持续到花期结束后，这取决于环境温度。萌发花粉的存在不会引起柱头坏死，并且谷粒可能在不同的时间到达。在雌蕊开花期结束前，花粉管顶端一直留在柱头基部内。胚珠在柱头坏死后才发育。因此，不管它们到达的时间和花粉粒在柱头表面的原始位置如何，花粉管都有一个公平的胚珠起点。因此，不同的小配子体之间的竞争是可能的，尽管低授粉强度。我们的研究结果表明，当第一个花粉管穿透一个胚珠，这个胚珠开始超过另一个，即使另一个也被穿透，它的维管支持很快萎缩，雌配子体将萎缩。在本研究中从未观察到两个胚珠的受精。
The influence of the sequence of maternal tissue development inBetula pendulaupon the potential for male gamete selection was investigated, and the timing of the fixed abortion of one of the two ovules was determined. We used scanning electronic microscopy, confocal laser scanning microscopy, and blue light microscopy. The stigmas remain fresh throughout male anthesis, and may also last after its end, depending on ambient temperatures. The presence of germinated pollen does not induce stigmatic necrotization, and grains may arrive at different times. The pollen tube tips remain within the stigma base until the end of female anthesis. The ovules will not develop until after necrotization of the stigmas. The pollen tubes thus have a fair start to the ovules, regardless of their different arrival times and of the original positions of the pollen grains at the stigma surface. Therefore, competition among different microgametophytes is possible, in spite of low pollination intensity. Our results indicate that when the first pollen tube penetrates an ovule, this ovule starts to outgrow the other one, and even if the other is also penetrated, its vascular support soon atrophies and the megagametophyte will shrivel. Fertilization of both ovules was never seen in this study.