Convergent recruitment of new pollinators is triggered by independent hybridization events inNarcissus

Abstract

SummaryHybridization can generate new species if some degree of isolation prevents gene flow between the hybrids and their progenitors. The recruitment of novel pollinators by hybrids has been hypothesized to be one way in which such reproductive isolation can be achieved.We tested whether pollinators contributed to isolation between two natural Narcissus hybrids and their progenitors using pollination experiments, observations, plus morphological and floral-volatile measurements. These hybrids share the same maternal but different paternal progenitors.We found that only the hybrids were visited by and pollinated by ants. The two hybrids exceeded their progenitors in floral-tube aperture size and nectar production. The emission of floral volatiles by hybrid plants was not only equal to or higher than the progenitor species, but also contained some new compounds not produced by the progenitors.The recruitment of ants as novel pollinators in the hybrids involved the combination of increased nectar secretion and the production of novel floral scent compounds. A breakdown of chemical defence against ants may also be involved. This study provides support for the hypothesis that the recruitment of novel pollinators can contribute to reproductive isolation between hybrids and their progenitors.

Reproductive isolation between Salvia elegans and S. fulgens, two hummingbird‐pollinated sympatric sages

“…), unless they are able to attract different pollinator species (Marques et al . ) or colonise new habitats (Rieseberg et al . ).…”

A three‐genome five‐gene comprehensive phylogeny of the bulbous genus Narcissus (Amaryllidaceae) challenges current classifications and reveals multiple hybridization events

“…Additionally, they have mostly been tested on simulated data and/or only on datasets of very limited size (Jones & al., 2014). Because of the size and complexity of our datasets, we analyzed the phylogenetic results together with our own independent evidence based on cytogenetic data, morphology and reproductive biology (Marques & al., 2010(Marques & al., , 2012b(Marques & al., , 2016, as well as with previous evidence from various sources (see introduction) in order to identify the causes of the underlying incongruence (Wendel & Doyle, 1998). Below we only present highly likely cases of hybridization in Narcissus revealed by phylogenetic incongruence and supported by independent data, but further specific studies are needed to support other potential "minor" cases of hybridization (e.g., N. bulbocodium subsp.…”

“…In particular, a considerable number of studies have focused on the evolution of heterostyly in this genus (e.g., Arroyo & Dafni, 1995;Barrett & al., 1996Barrett & al., , 2004Pérez & al., 2004Pérez & al., , 2006Barrett & Harder 2005;Medrano & al., 2005). Other subjects of plant evolution that have been addressed using Narcissus species include natural hybridization (Marques & al., 2007(Marques & al., , 2011(Marques & al., , 2012b(Marques & al., , 2016 as well as differentiation and other processes at the micro-evolutionary level (Jiménez & al., 2009;. In addition to being a model system for basic research, Narcissus has also been the subject of drug screening focused on diseases such as Alzheimer's (Heinrich & Teoh, 2004;Vrondeli & al., 2005;Rønsted & al., 2008;Berkov & al., 2014).…”

Is homoploid hybrid speciation that rare? An empiricist’s view

“…Furthermore, we think that if there is evidence that a hybridization event has given rise to an established, persistent, morphologically and ecologically distinct hybrid lineage, the recognition of this fact should not be compromised by whether or not we can demonstrate that hybridization was directly the cause of RI. Hybridization can be causative of mechanisms that contribute to enhancing RI in hybrid lineages, for example, the sorting of chromosomal rearrangements along the recombinational speciation model (Lai et al, 2005;Lukhtanov et al, 2015) or the occurrence of new traits that change mating patterns (Vereecken et al, 2010;Selz et al, 2014;Marques et al, 2016;Ma et al, 2016). In addition, intrinsic changes in the hybrids not directly causing RI between hybrid lineages and their progenitors may ultimately lead to external RI by facilitating the colonization of new niches (Grant, 1981;Gross and Rieseberg, 2005).…”