THE CONSEQUENCES OF SELF-POLLINATION IN ASCLEPIAS-EXALTATA, A SELF-INCOMPATIBLE MILKWEED
THE CONSEQUENCES OF SELF-POLLINATION IN ASCLEPIAS-EXALTATA, A SELF-INCOMPATIBLE MILKWEED
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DOI：
10.2307/2445118
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发表时间：
1993-01-01
影响因子：
3
通讯作者：
WYATT, R
中科院分区：
文献类型：
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作者：
BROYLES, SB;WYATT, R
我们研究了自花授粉对马利筋（一种自交不亲和的马利筋）结实和结实的影响。在五个处理中的每个处理中，对138朵花进行了总共1,380次人工授粉。在每个处理中，将两个花粉粒放置在相邻的柱头室中，其将花粉管传递到同一子房。处理1和2涉及同时将两个自花授粉（处理1）或两个异花授粉（处理2）到相邻的柱头室。自花授粉后没有果实产生，但23%的异花授粉花成熟果实。剩下的三个实验授粉处理是在异花授粉之前24小时的自花授粉（处理3），同时自花和异花授粉（处理4），以及在自花授粉之前24小时的异花授粉（处理5）。处理3-5的坐果率分别比对照降低81%、49%和29%。在异花授粉前24小时接受自花授粉的花，结实率也显著降低。使用遗传标记，我们观察到只有0.6%的种子来自自花授粉。我们的数据强烈表明，马利筋自花授粉不仅浪费花粉，而且大大减少了胚珠和子房的数量，否则可能成熟的果实和种子异花授粉后。
We investigated the effect of self-pollination on fruit- and seed-set in Asclepias exaltata, a self-incompatible milkweed. A total of 1,380 hand-pollinations were performed on 138 flowers in each of five treatments. In each treatment, two pollinia were placed in adjacent stigmatic chambers, which transmitted pollen tubes to the same ovary. Treatments 1 and 2 involved simultaneous placement of two self-pollinia (treatment 1) or two cross-pollinia (treatment 2) into adjacent stigmatic chambers. No fruits were produced after self-pollinations, but 23% of the cross-pollinated flowers matured fruits. The three remaining experimental pollination treatments were self-pollination preceding cross-pollination by 24 hr (treatment 3), simultaneous self- and cross-pollination (treatment 4), and cross-pollination preceding self-pollination by 24 hr (treatment 5). Compared with that in flowers receiving only cross-pollen, fruit-set in treatments 3-5 was reduced 81%, 49%, and 29%, respectively. Seed-set was also significantly reduced in flowers receiving self-pollen 24 hr in advance of the cross-pollen. Using genetic markers, we observed that only 0.6% of seeds resulted from self-pollination. Our data strongly suggest that self-pollination in milkweeds not only wastes pollen but also greatly reduces the number of ovules and ovaries that might otherwise mature fruits and seeds after cross-pollination.