Use of Taxon-Specific Competitive-Priming PCR to Study Host Specificity, Hybridization, and Intergroup Gene Flow in Intersterility Groups ofHeterobasidion annosum

1996 ◽  
Vol 86 (5) ◽  
pp. 543 ◽  
Author(s):  
Matteo Garbelotto
Keyword(s):  
Gene Flow ◽  
Host Specificity ◽  
Intersterility Groups

Relative abundance and potential dispersal range of intersterility groups of Heterobasidion annosum in pure and mixed forests

2001 ◽  
Vol 79 (9) ◽  
pp. 1057-1065 ◽  
Author(s):  
Paolo Gonthier ◽  
Matteo Garbelotto ◽  
Giovanna Cristina Varese ◽  
Giovanni Nicolotti
Keyword(s):  
Gene Flow ◽  
Host Specificity ◽  
Mixed Forest ◽  
Abies Alba ◽  
Heterobasidion Annosum ◽  
Silver Fir ◽  
Airborne Spores ◽  
Forest Pathogen ◽  
Limited Gene Flow ◽  
Intersterility Groups

In Europe the forest pathogen Heterobasidion annosum (Fr.) Bref. includes the S, P, and F intersterility groups (ISGs), each displaying a preferential specialization on Norway spruce (Picea abies (L.) Karst.), pine, and silver fir (Abies alba Mill.), respectively. In this paper, we present data about (i) H. annosum ISGs frequency in different forest types, (ii) the degree of host specificity of each ISG, (iii) the significance of the potential movement of airborne spores among forests, and (iv) the occurrence of S–P chimeras in the northwestern Alps. Using woody spore traps, we sampled natural pure spruce and fir forests and a mixed spruce-fir forest. The ISG of 582 spores was determined by ISG-diagnostic taxon-specific competitive priming (TSCP) polymerase chain reaction (PCR) combined with PCR-mediated detection of ISG-specific introns in the ML5–ML6 DNA region of the mitochondrial large ribosomal RNA (mt LrRNA). All three ISGs were found, and a strong correlation was observed between the F ISG and fir and the S ISG and spruce. In the mixed forest, no clear relationship between tree host species and host-specialized ISGs was found. In spite of a relative dominance of fir in the overstory of the mixed stand, the fir-associated F ISG represented only 11% of the total number of spores collected. This discrepancy was explained by the recent establishment of firs at this site. No S–P nuclear-mitochondrial chimeras were found. This suggests limited gene flow between these ISGs.Key words: Heterobasidion annosum, host specificity, ISGs, gene flow, PCR, Alps.

Asymmetric hybridization and gene flow between Joshua trees (Agavaceae:Yucca) reflect differences in pollinator host specificity

2012 ◽  
Vol 22 (2) ◽  
pp. 437-449 ◽  
Author(s):  
Tyler N. Starr ◽  
Katherine E. Gadek ◽  
Jeremy B. Yoder ◽  
Ramona Flatz ◽  
Christopher I. Smith
Keyword(s):  
Gene Flow ◽  
Host Specificity ◽  
Joshua Trees

scholarly journals The European S and F intersterility groups of Heterobasidion annosum may represent sympatric protospecies

1998 ◽  
Vol 76 (3) ◽  
pp. 397-409 ◽  
Author(s):  
Matteo Garbelotto ◽  
William J Otrosina ◽  
Fields W Cobb ◽  
Thomas D Bruns
Keyword(s):  
Host Specificity ◽  
Abies Alba ◽  
Pcr Primers ◽  
Eastern Alps ◽  
Heterobasidion Annosum ◽  
Pcr Analysis ◽  
Close Relative ◽  
Restricted Gene Flow ◽  
Length Polymorphisms ◽  
Intersterility Groups

In those regions of Europe where they coexist, the F and S intersterility groups (ISGs) of Heterobasidion annosum (Fr.) Bref. are primarily found on Abies spp. and Picea abies (L.) Karst., respectively. Eighty-three isolates of H. annosum were collected from Abies alba Mill. from 19 sites in Italy, including 10 Abies-Picea mixed conifer stands in the eastern Alps. The ISGs of a subsample of 34 isolates were determined by ISG-diagnostic arbitrary-primed (AP) PCR primers. For a subsample of 16 isolates, including two S isolates from Norway and one S isolate from California, nuclear markers generated by AP-PCR analysis, and mitochondrial markers generated by restriction fragment length polymorphisms and sequencing of the ML5-ML6 region of the mitochondrial large ribosomal RNA gene indicated that, in Europe, (i) the F and S ISGs can be found in the same forest stand but they are two genetically distinct units with restricted gene flow between them; (ii) each of the two ISGs is monophyletic and may lack strong genetic substructuring in subpopulations; and (iii) the two ISGs are closely related to each other and their nearest common close relative is the allopatric S ISG from North America. By combining these results with paleobotanical information and results from previous studies, we postulate a recent sympatric divergence of these two groups driven by differential host specificity and mating barriers.Key words: species complex, protospecies, sympatric, mating barriers, host specificity.

Population genetic structure and phenotypic diversity of Aspidodera raillieti (Nematoda: Heterakoidea), a parasite of Didelphini marsupials in Brazil’s South and Southeast Atlantic Forest

2021 ◽  
Author(s):  
Karina Varella ◽  
Roberto do Val Vilela ◽  
Rosana Gentile ◽  
Thiago dos Santos Cardoso ◽  
Sócrates Fraga da Costa-Neto ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Host Specificity ◽  
Atlantic Forest ◽  
Host Species ◽  
Population Genetic ◽  
Fixation Index ◽  
The South ◽  
Genetic Structuring ◽  
Morphometric Variation

Abstract Background: Population genetics of parasites may be influenced by host specificity, life-cycle, geographical distance, evolutionary history, and host-populations structure. The nematode Aspidodera raillieti infects different marsupial and rodent hosts in the Nearctic and Neotropical regions, implying a presumably significant gene flow among populations. However, niche diversification of A. raillieti main hosts in superimposed areas may provide conditions for population genetic structuring within this parasite species. We examined the genetic structuring of A. raillieti infecting three marsupial species co-occurring along South and Southeast Brazilian Atlantic Forest, a hotspot of biodiversity.Methods: We employed morphometric analyses and partial mitochondrial cytochrome c oxidase I gene sequences (MT-CO1) to characterize populations via phylogenetic and phylogeographic analyses.Results: Among 175 A. raillieti specimens recovered from marsupial hosts Didelphis aurita, D. albiventris, and Philander quica, we identified 99 MT-CO1 haplotypes forming four groups in phylogenetic trees and networks. Clades I and II encompassed parasites of D. albiventris from the South region, Clade III comprised parasites of D. aurita from the South and Southeast regions, and Clade IV encompassed parasites of D. aurita and D. albiventris from the South and Southeast regions and parasites of Philander quica from the South region. High genetic differentiation between clades, with a high fixation index and greater genetic variation in the analysis of molecular variance (AMOVA), indicated low gene flow between clades. Haplotypes shared among host species revealed a lack of host specificity. Significant correlation in the Mantel test, suggested parasite isolation by distance, although there was no evidence of geographic structure between populations. Negative values in neutrality tests for Clades III and IV suggested recent population expansion. Morphometric differentiation between A. raillieti specimens recovered from different host species, as well as from different localities, was more evident in males.Conclusion: The genetic structure of A. raillieti populations in the South and Southeast Atlantic Forest resulted from historical events rather than from current geographical distribution or host specificity. We also demonstrate morphometric variation associated with host species and localities, suggesting phenotypic plasticity to host attributes and to spatial variables.

Great Wall blocks gene flow

Nature ◽  
2003 ◽  
Author(s):  
HelenR. Pilcher
Keyword(s):  
Gene Flow ◽  
Great Wall
Sign in / Sign up

Export Citation Format

Share Document