Dataset Information

Natural hybridization between two butterfly bushes in Tibet: dominance of F₁ hybrids promotes strong reproductive isolation.

ABSTRACT:

Background

It has been recognized that a certain amount of habitat disturbance is a facilitating factor for the occurrence of natural hybridization, yet to date we are unaware of any studies exploring hybridization and reproductive barriers in those plants preferentially occupying disturbed habitats. Buddleja plants (also called butterfly bush) generally do grow in disturbed habitats, and several species with hybrid origin have been proposed, based solely on morphological evidence.

Results

In the present study, we test the hypothesis that B. × wardii is of natural hybridization origin in two sympatric populations of three taxa including B. × wardii and its parents (B. alternifolia and B. crispa) plus 4 referenced parental populations, using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii is likely to be a hybrid between B. alternifolia and B. crispa, and moreover, we confirm that most of the hybrids examined are F₁s. That these plants are F₁s is further supported by morphology, as no transgressive characters were detected. B. crispa was found to be the maternal parent in the Bahe (BH) population, from cpDNA evidence. However, in the Taji (TJ) population, the direction of hybridization was difficult to establish due to the shared cpDNA haplotypes between B. alternifolia and B. crispa, however we still predicted a similar unidirectional hybridization pattern due to results from cross-specific pollination treatments which supported the "SI × SC rule".

Conclusions

The presence of mainly F₁ hybrids can successfully impede gene flow and thus maintain species boundaries in parental species in a typical distribution of Buddleja, i.e. in disturbed habitats.

SUBMITTER: Liao R

PROVIDER: S-EPMC7945306 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature

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Publications

Natural hybridization between two butterfly bushes in Tibet: dominance of F<sub>1</sub> hybrids promotes strong reproductive isolation.

Liao Rongli R Sun Weibang W Ma Yongpeng Y

BMC plant biology 20210310 1

<h4>Background</h4>It has been recognized that a certain amount of habitat disturbance is a facilitating factor for the occurrence of natural hybridization, yet to date we are unaware of any studies exploring hybridization and reproductive barriers in those plants preferentially occupying disturbed habitats. Buddleja plants (also called butterfly bush) generally do grow in disturbed habitats, and several species with hybrid origin have been proposed, based solely on morphological evidence.<h4>Re ...[more]

PMID: 33691631

Similar Datasets

Project description:Gene flow between populations that are adapting to distinct environments may be restricted if hybrids inherit maladaptive, intermediate phenotypes. This phenomenon, called extrinsic postzygotic isolation (EPI), is thought to play a critical role in the early stages of speciation. However, despite its intuitive appeal, we know surprisingly little about the strength and prevalence of EPI in nature, and even less about the specific phenotypes that tend to cause problems for hybrids. In this study, we searched for EPI among allopatric populations of the butterfly Euphydryas editha that have specialized on alternative host plants. These populations recall a situation thought typical of the very early stages of speciation. They lack consistent host-associated genetic differentiation at random nuclear loci and show no signs of reproductive incompatibility in the laboratory. However, they do differ consistently in diverse host-related traits. For each of these traits, we first asked whether hybrids between populations that use different hosts (different-host hybrids) were intermediate to parental populations and to hybrids between populations that use the same host (same-host hybrids). We then conducted field experiments to estimate the effects of intermediacy on fitness in nature. Our results revealed strong EPI under field conditions. Different-host hybrids exhibited an array of intermediate traits that were significantly maladaptive, including four behaviors. Intermediate foraging height slowed the growth of larvae, while intermediate oviposition preference, oviposition site height, and clutch size severely reduced the growth and survival of the offspring of adult females. We used our empirical data to construct a fitness surface on which different-host hybrids can be seen to fall in an adaptive valley between two peaks occupied by same-host hybrids. These findings demonstrate how ecological selection against hybrids can create a strong barrier to gene flow at the early stages of adaptive divergence.

Dataset Information

Natural hybridization between two butterfly bushes in Tibet: dominance of F₁ hybrids promotes strong reproductive isolation.

Background

Results

Conclusions

Publications

Natural hybridization between two butterfly bushes in Tibet: dominance of F<sub>1</sub> hybrids promotes strong reproductive isolation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Natural hybridization between two butterfly bushes in Tibet: dominance of F1 hybrids promotes strong reproductive isolation.

Background

Results

Conclusions

Publications

Natural hybridization between two butterfly bushes in Tibet: dominance of F<sub>1</sub> hybrids promotes strong reproductive isolation.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Natural hybridization between two butterfly bushes in Tibet: dominance of F₁ hybrids promotes strong reproductive isolation.