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Parameiosis in the entomopathogenic fungs Metarhizium anisopliae (Metsh.) sorokin

 

 

E. BagagliI,II; M.C.C. ValadaresI,III; J.L. AzevedoI

IInstituto de Genética, ESALQ-USP, Caixa Postal 83, 13400 Piracicaba, SP, Brasil. Send correspondence to J.L.A.
IIPresent address: Departamento de Microbiologia e Imunologia, UNESP, 18600 Botucatu, SP, Brasil
IIICENARGEN/EMBRAPA, S.A.I.N., Parque Rural, 70000 Brasilia, DF, Brasil

 

 

ABSTRACT

Variations in the parasexual cycle, especially in relation to diploid instability, have been described in several fungal species. The process has been designated "parameiosis"; it is characterized by the emergence, from heterokaryons, of haploid and diploid recombinants, as well as the typical diploids normally recovered in a parasexual cycle. In the present work the occurrence of a similar process in Metarhizium anisopliae has been investigated. Conidia from heterokaryons formed between well-marked mutant strains, when plated onto appropriate selective media, resulted in the recovery of at least three main groups of colonies. The first group consisted of very unstable diploids or hyperhaploids; these, on plating of their conidia, produced several types of recombinant haploids. The second group consisted of already stable haploid recombinants formed by the breakdown of diploid heterozygous nuclei before conidial formation; and a third group, heterokaryotic colonies, which segregate only parental types. Parameiosis has been found in several Deuteromycetes and may play an important role in increasing genetic variability in these fungi.

Keywords: Parameiosis; Entomopathogenic fungus; Metarhizium anisopliae.

 

 

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