Premium
Recombination within sympatric cryptic species of the insect pathogenic fungus Metarhizium anisopliae
Author(s) -
Bidochka Michael J.,
Small CherrieLee N.,
Spironello Michael
Publication year - 2005
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-5822.2005.00823.x
Subject(s) - biology , species complex , monophyly , internal transcribed spacer , reproductive isolation , metarhizium anisopliae , sympatric speciation , insect , phylogenetic tree , ribosomal dna , concerted evolution , zoology , botany , genetics , evolutionary biology , gene , biological pest control , clade , sociology , population , demography
Summary Metarhizium anisopliae is an insect pathogenic fungus with a worldwide distribution. It is being developed and used as a biocontrol agent against a wide range of insect pests but relatively little is known of the life history of this fungus. We tested hypotheses concerning reproductive isolation and recombination in a sample of heat‐active (ability to grow at 37°C) and cold‐active (ability to grow at 8°C) sympatrically occurring isolates of M. anisopliae from Ontario, Canada by assaying nucleotide sequence variation at six polymorphic loci: the internally transcribed spacer (ITS) region of the nuclear ribosomal DNA repeat, and portions of calmodulin (CAL), chitin synthase (CHS), subtilisin‐like protease (PR1), neutral trehalase (NTL) and actin (ACT)‐encoding genes. The most parsimonious trees constructed showed a topology consistent with the heat‐active and cold‐active isolates as two monophyletic groups. We then applied Genealogical Concordance Phylogenetic Species Recognition (GCPSR) to the genealogical trees and concluded that the transition from concordance among branches to incongruity among branches delimited two species of M. anisopliae within Ontario. The GCPSR of two species was supported by intraspecific incongruity within each species when tested using the Partition Homogeneity test, indicating recombination. The GCPSR of two species also corresponded to the heat‐active and cold‐active groups. As the groups are morphologically indistinguishable we applied the term ‘cryptic species’. Therefore, the sympatrically occurring heat‐active and cold‐active isolates represent different cryptic species with a history of recombination among isolates within each species.