Peterson Megan L, Miller Timothy J, Kay Kathleen M
Ecology and Evolutionary Biology, University of California Santa Cruz, 1156 High Street, Santa Cruz, California 95064 USA.
Am J Bot. 2015 Mar;102(3):396-406. doi: 10.3732/ajb.1400415. Epub 2015 Mar 11.
•
Ultraviolet (UV) floral patterns are common in angiosperms and mediate pollinator attraction, efficiency, and constancy. UV patterns may vary within species, yet are cryptic to human observers. Thus, few studies have explicitly described the distribution or ecological significance of intraspecific variation in UV floral patterning. Here, we describe the geographic distribution and pattern of inheritance of a UV polymorphism in the model plant species Mimulus guttatus (Phrymaceae). We then test whether naturally occurring UV phenotypes influence pollinator interactions within M. guttatus.•
We document UV patterns in 18 annual and 19 perennial populations and test whether UV pattern is associated with life history. To examine the pattern of inheritance, we conducted crosses within and between UV phenotypes. Finally, we tested whether bee pollinators discriminate among naturally occurring UV phenotypes in two settings: wild bee communities and captive Bombus impatiens.•
Within M. guttatus, perennial populations exhibit a small bulls-eye pattern, whereas a bilaterally symmetric runway pattern occurs mainly in annual populations. Inheritance of UV patterning is consistent with a single-locus Mendelian model in which the runway phenotype is dominant. Bee pollinators discriminate against unfamiliar UV patterns in both natural and controlled settings.•
We describe a widespread UV polymorphism associated with life history divergence within Mimulus guttatus. UV pattern influences pollinator visitation and should be considered when estimating reproductive barriers between life history ecotypes. This work develops a new system to investigate the ecology and evolution of UV floral patterning in a species with extensive genomic resources.
研究前提：紫外线（UV）花部图案在被子植物中很常见，可介导传粉者的吸引、效率和专一性。UV图案在物种内可能存在差异，但对人类观察者来说是隐蔽的。因此，很少有研究明确描述UV花部图案种内变异的分布或生态意义。在这里，我们描述了模式植物黄花沟酸浆（透骨草科）中一种UV多态性的地理分布和遗传模式。然后，我们测试自然出现的UV表型是否会影响黄花沟酸浆内的传粉者相互作用。
方法：我们记录了18个一年生和19个多年生种群的UV图案，并测试UV图案是否与生活史相关。为了研究遗传模式，我们在UV表型内和表型之间进行了杂交。最后，我们在两种环境下测试蜜蜂传粉者是否能区分自然出现的UV表型：野生蜜蜂群落和圈养的凤蝶熊蜂。
主要结果：在黄花沟酸浆中，多年生种群呈现出小的靶心图案，而两侧对称的跑道图案主要出现在一年生种群中。UV图案的遗传符合单基因孟德尔模型，其中跑道表型是显性的。蜜蜂传粉者在自然和受控环境中都对不熟悉的UV图案有歧视。
结论：我们描述了一种与黄花沟酸浆生活史差异相关的广泛存在的UV多态性。UV图案影响传粉者的访问，在估计生活史生态型之间的生殖障碍时应予以考虑。这项工作开发了一个新系统，用于研究具有丰富基因组资源的物种中UV花部图案的生态学和进化。
