Floral biology of large-flowered Thelymitra species (Orchidaceae) and their hybrids in Western Australia
Floral biology of large-flowered Thelymitra species (Orchidaceae) and their hybrids in Western Australia
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DOI：
10.7751/telopea2013020
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发表时间：
2013-11
期刊：
影响因子：
0.7
通讯作者：
Retha Edens-Meier;Eric Westhus;P. Bernhardt
中科院分区：
文献类型：
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作者：
Retha Edens-Meier;Eric Westhus;P. Bernhardt
在历史上，只有少数的大花属Thelymitra物种被确定为专性的远系繁殖。比较了两个居群的花器形态、花粉-雌蕊相互作用、传粉生态和种间杂交。macrophylla的花期与T. antennifera（Tenterden）和T. crinita（Lesmurdie）。利用温室收集的T. crinita和T.在国王公园和植物园（珀斯，华盛顿州）。T.大叶种在不同地点间差异显著。气候条件对T. crinita vs.大叶而所有三种Thelymitra spp.在温暖、阳光明媚的早晨开放，下午晚些时候关闭，T。在Lesmurdie的crinita与T.大叶T. macrophylla和T.在柱头表面施用Thelymitra花粉后，毛被显着减少，但不减少花粉囊的去除。这两个物种的花都是自交亲和的，但两个物种都不进行机械自花授粉（自花受精）。荧光显微镜也表明，这两个物种是相互兼容的。在这两个网站的所有三个物种的自然率花粉清除昆虫都很低。T.花粉在受体柱头上的自然沉积率显着较高。crinita vs.但两种植物的花粉沉积量均小于12%。传粉昆虫的观察和收集是罕见的，传粉媒介仅限于少数的多效性，雌蜂在家庭蜜蜂，Colletidae，和Halictidae。我们发现了大量的T. antennifera和T.在Tenterden的T. macrophylla中，T. crinita和T. Lesmurdie的macrophylla。正如预期的那样，所有的杂种都表现出介于两个假定的亲本物种之间的特征，包括T。海百合大叶种标本。由于脊柱畸形，大多数T。Antennifera X T. macrophylla花似乎不能将它们的花粉粒附着到它们各自的小喙上。
Historically, only a few large flowered species in the genus Thelymitra were identified as obligate out-breeders. We compared floral presentation, pollen-pistil interactions, pollination ecology, and interspecific hybridization in two populations of T. macrophylla where its flowering periods overlapped with T. antennifera (Tenterden) and T. crinita (Lesmurdie) respectively. Pollen-pistil interactions were studied using glasshouse collections of T. crinita and T. macrophylla at the Kings Park and Botanic Garden (Perth, WA). The number of flowers/inflorescence in T. macrophylla varied significantly between sites. Climatic conditions influenced flower opening and closing regimes differently in T. crinita vs. T. macrophylla. While all three Thelymitra spp. opened on warm, sunny mornings and closed by late afternoon, T. crinita at Lesmurdie was significantly more likely to open its perianth segments on cool days compared to the co-blooming, sympatric flowers of T. macrophylla. The floral lifespans of individual flowers of T. macrophylla and T. crinita were reduced significantly following application of Thelymitra pollen onto the stigmatic surface but were not reduced by pollinarium removal. Flowers of both species were self-compatible but neither species self-pollinated mechanically (autogamy). Fluorescence microscopy also showed that both species were inter-compatible. Natural rates of pollinarium removal by insects were low in all three species at both sites. Natural rates of pollen deposition on receptive stigmas were significantly higher in T. crinita vs. T. macrophylla but pollen deposition was less than 12% in both species. Observations and collections of pollinators were infrequent and pollinaria vectors were restricted to a few polylectic, female bees in the families Apidae, Colletidae, and Halictidae. We found a large number of hybrids between T. antennifera and T. macrophylla at Tenterden but few obvious hybrids between T. crinita and T. macrophylla at Lesmurdie. As expected, all hybrids showed characteristics intermediate between their two putative parent species, including pollen configuration in the T. crinita X T. macrophylla specimens. Due to malformations of the column, the majority of T. antennifera X T. macrophylla flowers appeared unable to attach their pollinia to their respective rostella.