Patterns of mating for the European corn borer (
Crenate broomrape (
- NSF-PAR ID:
- 10370875
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecology and Evolution
- Volume:
- 12
- Issue:
- 3
- ISSN:
- 2045-7758
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
Abstract Ostrinia nubilalis ) moth depend in part on variation in sex‐pheromone blend. The ratio of (E )‐11‐ and (Z )‐11‐tetradecenyl acetate (E11‐ and Z11‐14:OAc) in the pheromone blend that females produce and males respond to differs between strains ofO. nubilalis . Populations also vary in female oviposition preference for and larval performance on maize (C4) and nonmaize (C3) host plants. The relative contributions of sexual and ecological trait variation to the genetic structure ofO. nubilalis remains unknown. Host‐plant use (13C/14C ratios) and genetic differentiation were estimated among sympatric E and Z pheromone strainO. nubilalis males collected in sex‐pheromone baited traps at 12 locations in Pennsylvania and New York between 2007 and 2010. Among genotypes at 65 single nucleotide polymorphism marker loci, variance at a position in the pheromone gland fatty acyl‐reductase (pgfar ) gene at the locus responsible for determining female pheromone ratio (Pher ) explained 64% of the total genetic differentiation between males attracted to different pheromones (male response,Resp ), providing evidence of sexual inter‐selection at these unlinked loci. Principal coordinate, Bayesian clustering, and distance‐based redundancy analysis (dbRDA) demonstrate that host plant history or geography does not significantly contribute to population variation or differentiation among males. In contrast, these analyses indicate that pheromone response andpgfar ‐defined strain contribute significantly to population genetic differentiation. This study suggests that behavioural divergence probably plays a larger role in driving genetic variation compared to host plant‐defined ecological adaptation. -
more » « less
Abstract Understanding the consequences of exotic diseases on native forests is important to evolutionary ecology and conservation biology because exotic pathogens have drastically altered US eastern deciduous forests.
Cornus florida L. (flowering dogwood tree) is one such species facing heavy mortality. Characterizing the genetic structure ofC. florida populations and identifying the genetic signature of adaptation to dogwood anthracnose (an exotic pathogen responsible for high mortality) remain vital for conservation efforts. By integrating genetic data from genotype by sequencing (GBS) of 289 trees across the host species range and distribution of disease, we evaluated the spatial patterns of genetic variation and population genetic structure ofC. florida and compared the pattern to the distribution of dogwood anthracnose. Using genome‐wide association study and gradient forest analysis, we identified genetic loci under selection and associated with ecological and diseased regions. The results revealed signals of weak genetic differentiation of three or more subgroups nested within two clusters—explaining up to 2%–6% of genetic variation. The groups largely corresponded to the regions within and outside the eastern Hot‐Continental ecoregion, which also overlapped with areas within and outside the main distribution of dogwood anthracnose. The fungal sequences contained in the GBS data of sampled trees bolstered visual records of disease at sampled locations and were congruent with the reported range ofDiscula destructiva , suggesting that fungal sequences within‐host genomic data were informative for detecting or predicting disease. The genetic diversity between populations at diseased vs. disease‐free sites across the range ofC. florida showed no significant difference. We identified 72 single‐nucleotide polymorphisms (SNPs) from 68 loci putatively under selection, some of which exhibited abrupt turnover in allele frequencies along the borders of the Hot‐Continental ecoregion and the range of dogwood anthracnose. One such candidate SNP was independently identified in two prior studies as a possible L‐type lectin‐domain containing receptor kinase. Although diseased and disease‐free areas do not significantly differ in genetic diversity, overall there are slight trends to indicate marginally smaller amounts of genetic diversity in disease‐affected areas. Our results were congruent with previous studies that were based on a limited number of genetic markers in revealing high genetic variation and weak population structure inC. florida . -
more » « less
Abstract Aim We used genome‐scale sampling to assess the phylogeography of a group of topminnows in the
Fundulus notatus species complex. Two of the species have undergone extensive range expansions resulting in broadly overlapping distributions, and sympatry within drainages has provided opportunities for hybridization and introgression. We assessed the timing and pattern of range expansion in the context of late Pleistocene–Holocene drainage events and evaluated the evidence for introgressive hybridization between species.Location Central and southern United States including drainages of the Gulf of Mexico Coastal Plain and portions of the Mississippi River drainage in and around the Central Highlands.
Taxon Topminnows, Genus
Fundulus , subgenusZygonectes —Fundulus notatus, Fundulus olivaceus, Fundulus euryzonus .Methods We sampled members of the
F. notatus species complex throughout their respective ranges, including numerous drainage systems where species co‐occur. We collected genome‐wide single nucleotide polymorphisms (SNP s) using the genotype‐by‐sequencing (GBS ) method and subjected data to population genetic analyses to infer the population histories of both species, including explicit tests for admixture and introgression. The methods employed includedSTRUCTURE , principal coordinates analysis, TreeMix and approximate Bayesian computation.Results Genetic data are presented for 749 individuals sampled from 14
F. notatus , 20F. olivaceus and 2F. euryzonus populations. Members of the species complex differed in phylogeographic structure, withF. notatus exhibiting geographic clusters corresponding to Pleistocene coastal drainages andF. olivaceus comparatively lacking in phylogeographic structure. Evidence for interspecific introgression varied by drainage.Main conclusions Populations of
F. notatus andF. olivaceus exhibited contrasting patterns of lineage diversity among coastal drainages, indicating interspecific differences in their Pleistocene southern refugia. Phylogeographic patterns in both species indicated that range expansions into the northern limits of contemporary distributions coincided with and continued subsequent to the Last Glacial Maximum. There was evidence of introgression between species in some, but not all drainages where the species co‐occur, in a pattern that is correlated with previous estimates of hybridization rates. -
more » « less
Abstract The Hengduan Mountains region is a biodiversity hotspot known for its topologically complex, deep valleys and high mountains. While landscape and glacial refugia have been evoked to explain patterns of interspecies divergence, the accumulation of intra‐species (i.e., population level) genetic divergence across the mountain‐valley landscape in this region has received less attention. We used genome‐wide restriction site‐associated DNA sequencing (RADseq) to reveal signatures of Pleistocene glaciation in populations of
Thitarodes shambalaensis (Lepidoptera: Hepialidae), the host moth of parasiticOphiocordyceps sinensis (Hypocreales: Ophiocordycipitaceae) or caterpillar fungus” endemic to the glacier of eastern Mt. Gongga. We used moraine history along the glacier valleys to model the distribution and environmental barriers to gene flow across populations ofT .shambalaensis . We found that moth populations separated by less than 10 km exhibited valley‐based population genetic clustering and isolation‐by‐distance (IBD), while gene flow among populations was best explained by models using information about their distributions at the local last glacial maximum (LGML, 58 kya), not their contemporary distribution. Maximum likelihood lineage history among populations, and among subpopulations as little as 500 m apart, recapitulated glaciation history across the landscape. We also found signals of isolated population expansion following the retreat of LGMLglaciers. These results reveal the fine‐scale, long‐term historical influence of landscape and glaciation on the genetic structuring of populations of an endangered and economically important insect species. Similar mechanisms, given enough time and continued isolation, could explain the contribution of glacier refugia to the generation of species diversity among the Hengduan Mountains. -
more » « less
Abstract Genetic diversity provides populations with the possibility to persist in ever‐changing environments, where selective regimes change over time. Therefore, the long‐term survival of a population may be affected by its level of genetic diversity. The Mexican howler monkey (
Alouatta palliata mexicana ) is a critically endangered primate restricted to southeast Mexico. Here, we evaluate the genetic diversity and population structure of this subspecies based on 83 individuals from 31 groups sampled across the distribution range of the subspecies, using 29 microsatellite loci. Our results revealed extremely low genetic diversity (H O = 0.21,H E = 0.29) compared to studies of otherA. palliata populations and to otherAlouatta species. Principal component analysis, a Bayesian clustering method, and analyses of molecular variance did not detect strong signatures of genetic differentiation among geographic populations of this subspecies. Although we detect small but significantF STvalues between populations, they can be explained by a pattern of isolation by distance. These results and the presence of unique alleles in different populations highlight the importance of implementing conservation efforts in multiple populations across the distribution range ofA. p. mexicana to preserve its already low genetic diversity. This is especially important given current levels of population isolation due to the extreme habitat fragmentation across the distribution range of this primate.
