Patterns of Mating in Wild Sunflower Hybrid Zones

Evolution ◽  
1998 ◽  
Vol 52 (3) ◽  
pp. 713 ◽  
Author(s):  
Loren H. Rieseberg ◽  
Stuart J. E. Baird ◽  
Andree M. Desrochers
Keyword(s):  
Hybrid Zones ◽  
Wild Sunflower

scholarly journals PATTERNS OF MATING IN WILD SUNFLOWER HYBRID ZONES

Evolution ◽  
1998 ◽  
Vol 52 (3) ◽  
pp. 713-726 ◽  
Author(s):  
Loren H. Rieseberg ◽  
Stuart J. E. Baird ◽  
Andrée M. Desrochers
Keyword(s):  
Hybrid Zones ◽  
Wild Sunflower

scholarly journals Landscape resistance constrains hybridization across contact zones in a reproductively and morphologically polymorphic salamander

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillermo Velo-Antón ◽  
André Lourenço ◽  
Pedro Galán ◽  
Alfredo Nicieza ◽  
Pedro Tarroso
Keyword(s):  
Contact Zone ◽  
Environmental Heterogeneity ◽  
Evolutionary Dynamics ◽  
Morphological Differentiation ◽  
Phenotypic Traits ◽  
Hybrid Zones ◽  
Landscape Resistance ◽  
Phenotypic Differentiation ◽  
Contact Zones

AbstractExplicitly accounting for phenotypic differentiation together with environmental heterogeneity is crucial to understand the evolutionary dynamics in hybrid zones. Species showing intra-specific variation in phenotypic traits that meet across environmentally heterogeneous regions constitute excellent natural settings to study the role of phenotypic differentiation and environmental factors in shaping the spatial extent and patterns of admixture in hybrid zones. We studied three environmentally distinct contact zones where morphologically and reproductively divergent subspecies of Salamandra salamandra co-occur: the pueriparous S. s. bernardezi that is mostly parapatric to its three larviparous subspecies neighbours. We used a landscape genetics framework to: (i) characterise the spatial location and extent of each contact zone; (ii) assess patterns of introgression and hybridization between subspecies pairs; and (iii) examine the role of environmental heterogeneity in the evolutionary dynamics of hybrid zones. We found high levels of introgression between parity modes, and between distinct phenotypes, thus demonstrating the evolution to pueriparity alone or morphological differentiation do not lead to reproductive isolation between these highly divergent S. salamandra morphotypes. However, we detected substantial variation in patterns of hybridization across contact zones, being lower in the contact zone located on a topographically complex area. We highlight the importance of accounting for spatial environmental heterogeneity when studying evolutionary dynamics of hybrid zones.

scholarly journals Microsatellites and petal morphology reveal new patterns of admixture in Orchis hybrid zones

2021 ◽  
Vol 108 (8) ◽  
pp. 1388-1404
Author(s):  
Leif Bersweden ◽  
Juan Viruel ◽  
Bertrand Schatz ◽  
Joanna Harland ◽  
Roberta Gargiulo ◽  
...  
Keyword(s):  
Hybrid Zones

Hybrid Zones and the Genetic Architecture of a Barrier to Gene Flow Between Two Sunflower Species

Genetics ◽  
1999 ◽  
Vol 152 (2) ◽  
pp. 713-727 ◽  
Author(s):  
Loren H Rieseberg ◽  
Jeannette Whitton ◽  
Keith Gardner
Keyword(s):  
Genetic Study ◽  
Genetic Architecture ◽  
Chromosomal Rearrangements ◽  
Pollen Sterility ◽  
Model Organisms ◽  
Hybrid Zones ◽  
Reproductive Barriers ◽  
Natural Hybrid ◽  
Generation Times ◽  
Helianthus Petiolaris

Abstract Genetic analyses of reproductive barriers represent one of the few methods by which theories of speciation can be tested. However, genetic study is often restricted to model organisms that have short generation times and are easily propagated in the laboratory. Replicate hybrid zones with a diversity of recombinant genotypes of varying age offer increased resolution for genetic mapping experiments and expand the pool of organisms amenable to genetic study. Using 88 markers distributed across 17 chromosomes, we analyze the introgression of chromosomal segments of Helianthus petiolaris into H. annuus in three natural hybrid zones. Introgression was significantly reduced relative to neutral expectations for 26 chromosomal segments, suggesting that each segment contains one or more factors that contribute to isolation. Pollen sterility is significantly associated with 16 of these 26 segments, providing a straightforward explanation of why this subset of blocks is disadvantageous in hybrids. In addition, comparison of rates of introgression across colinear vs. rearranged chromosomes indicates that close to 50% of the barrier to introgression is due to chromosomal rearrangements. These results demonstrate the utility of hybrid zones for identifying factors contributing to isolation and verify the prediction of increased resolution relative to controlled crosses.

Geographic variation in the structure of oak hybrid zones provides insights into the dynamics of speciation

2011 ◽  
Vol 20 (23) ◽  
pp. 4995-5011 ◽  
Author(s):  
YAN-FEI ZENG ◽  
WAN-JIN LIAO ◽  
RÉMY J. PETIT ◽  
DA-YONG ZHANG
Keyword(s):  
Geographic Variation ◽  
Hybrid Zones

Chloroplast DNA polymorphism reveals geographic structure and introgression in the Quercus crassifolia × Quercus crassipes hybrid complex in Mexico

Botany ◽  
2008 ◽  
Vol 86 (3) ◽  
pp. 228-239 ◽  
Author(s):  
E. Tovar-Sánchez ◽  
P. Mussali-Galante ◽  
R. Esteban-Jiménez ◽  
D. Piñero ◽  
D. M. Arias ◽  
...  
Keyword(s):  
Parental Species ◽  
Diversity Index ◽  
Hot Spot ◽  
Haplotype Diversity ◽  
Hybrid Zones ◽  
Chloroplast Microsatellite ◽  
Colonization Routes ◽  
Allopatric Populations ◽  
Genetic Structure Of Populations ◽  
Hybrid Complex

Quercus crassifolia H. & B. and Quercus crassipes H. & B. are two common temperate forest species in Mexico that form hybrids when they occur in mixed (sympatric) areas. In this study, we used chloroplast microsatellite haplotypes to infer phylogeographic patterns onto the genetic structure of populations of both parental species, thus defining probable colonization routes throughout Mexico. Haplotype diversity in seven hybrid zones and four allopatric sites with nonmixed (allopatric) populations of both putative parental species was analyzed. To determine the expansion and colonization routes for the two species, we carried out a nested clade phylogeographic analysis that would allow us to infer the haplotype correspondence to a phylogeographical approach. In spite of sharing many common populations, we determined that there is a different genetic historical colonization for Q. crassipes and for Q. crassifolia. Hybrid populations had the highest levels of genetic variation (Gv), Shannon diversity index (H), and haplotype number (nh) in comparison with nonmixed/allopatric populations of their putative parentals. Furthermore, populations of hybrid zones showed the highest values of genetic differentiation FST, RST . Moreover, both species share four distinctive cpDNA haplotypes, which were most likely acquired by introgression through hybrids located in several populations throughout the Eje Neovolcánico area. This last region was confirmed to be a “hot spot” for oak diversity, a place in which different maternal lineages merged.

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