HAPLOIDIZATION ANALYSIS OF HETEROZYGOUS DIPLOIDS OF THE ENTOMOGENOUS FUNGUSMETARHIZIUM ANISOPLIAE

Abstract

All stages of the parasexual cycle required for genetic analysis by haploidization have been demonstrated for Metarhizium anisopliae Metsch. (Sor). Heterokaryons have been synthesized from strains carrying complementing markers, and heterozygotic diploid colonies have been isolated from the heterokaryons. After exposure to benlate or botran, diploid colonies gave rise to a large number of haploid segregants. Analysis of the segregation of eight mutations in three crosses assigned these genes to five possible linkage groups. Use of the parasexual cycle should facilitate genetic analysis of pathogenesis and enhance the usefulness of this fungus for the control of insect pests.

Epistatic relationships and linkage among colour markers of the imperfect entomopathogenic fungus Metarhizium anisopliae

“…2. Data concerning linkage are consistent with those obtained by Bergeron and Messing-Al-Aidroos ( 1982).…”

“…Thus, ,the four colour mutations, lemon (lem), tan (tan), yellow (ylo), and brown (brn), are recessive and nonallelic. Gene action for spore-colour determination is nonautonomous, as reported by Messias and Azevedo (1980), and confirmed by Bergeron and Messing-Al-Aidroos (1982). Acr2 and ACRS were confirmed semidominant and dominant for acriflavine resistance, respectively, as earlier reported by Bergeron and Messing-Al-Aidroos (1 982).…”

“…Some heterokaryotic nuclei fuse to give heterozygous diploids. Following mitotic recombination in diploids, recombinant genotypes can be obtained (Bergeron and Messing-Al-Aidroos 1982;Magoon and Messing-Al-Aidroos 1984;Magoon 1984).…”

“…It could be due to selection against auxotrophic markers and epistasis of colour markers. Because diploids of M. anisopliae are relatively unstable (Bergeron and Messing-Al-Aidroos 1982), more vigorous sectors (prototrophs) could be favored.…”

Genetic variability in Metarhizium flavoviride revealed by telomeric fingerprinting

“…Evidence against this, however, is the fact that band intensity in CG291 was consistent, meaning that this strain could be a stable heterokaryon. Metarhizium is a Deuteromycete and has no recognised sexual cycle [16,17]. Parasexuality [18] and parameiosis [19], however, have been demonstrated to occur in M. anisopliae in the laboratory, but the frequency of recombination in the ¢eld in the absence of selection pressure is currently unknown.…”