Pollination ecology and maintenance of species integrity in co-occurring Disa racemosa L.f. and Disa venosa Sw. (Orchidaceae) in South Africa
Pollination ecology and maintenance of species integrity in co-occurring Disa racemosa L.f. and Disa venosa Sw. (Orchidaceae) in South Africa
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DOI：
10.2307/2992007
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发表时间：
1998-01-01
影响因子：
1.9
通讯作者：
Vogelpoel, L
中科院分区：
文献类型：
--
作者：
Johnson, SD;Steiner, KE;Vogelpoel, L
兰花Disa racemosa被发现由木蜂和花蜂（Xylocopa和Amegilla spp.）在南非开普花卉区的几个地点。一个精确的开花机制确保花粉囊总是附着在传粉者的中间一对腿上。D的花朵总状花序是没有回报的，但仍然吸引蜜蜂寻找新的食物来源。授粉和结果的成功率很低，从4到48%之间的8个研究群体。总状Disa通常与其非常相似的姐妹种Disa venosa同域共花，但更为罕见。唯一的特点是一贯不同的分类群是宽度的萼片。虽然这两个物种似乎有相同的传粉者，但它们之间的自然杂交从未被发现过。实验杂交的结果表明，不育障碍，而不是行为学或机械障碍，是负责维持混合种群的物种完整性。
The orchid Disa racemosa was found to be pollinated by xylocopine and anthophorine bees (Xylocopa and Amegilla spp.) at several sites in the Cape Floral Region of South Africa. A precise floral mechanism ensures that pollinaria are always attached to the middle pair of legs on the pollinator. Flowers of D. racemosa are nonrewarding, but nevertheless attract bees searching for new food sources. Levels of pollination and fruiting success were low, varying from 4 to 48% among the eight study populations. Disa racemosa is often sympatric and co-flowering with its very similar, though much rarer, sister species Disa venosa. The only character that is consistently different between the taxa is the width of the sepals. Although the two species appear to have the same pollinators, natural hybrids between them have never been found. The results of experimental crosses indicated that a sterility barrier, rather than ethological or mechanical barriers, is responsible for the maintenance of species integrity in mixed populations.