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Oxygen‐rich culture conditions enhance the conidial infectivity and the quality of two strains of Isaria fumosorosea for potentially improved biocontrol processes
Author(s) -
MirandaHernández Francisco,
SaucedoCastañeda Gerardo,
AlatorreRosas Raquel,
Loera Octavio
Publication year - 2014
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.3605
Subject(s) - infectivity , biological pest control , microbiology and biotechnology , biology , virology , botany , virus
BACKGROUND In addition to high production levels of conidia, the success of entomopathogenic fungi as biological control agents depends both on their prevalence under the environmental conditions found in open fields (resistance to stress) and on the capacity of these conidia to infect pests. This study compares conidium production, infectivity and resistance to thermal and osmotic stress in two strains of Isaria fumosorosea ( ARSEF 3302 and CNRCB1 ) grown either under a normal atmosphere (21% O 2 ) or using enriched oxygen pulses (26% O 2 ) . RESULTS After 180 h, the ARSEF 3302 strain with 26% O 2 pulses increased conidium production nearly fivefold compared with the normal atmosphere, while conidium production by the CNRCB1 strain decreased by 50% under O 2 pulses, relative to the values measured with the normal atmosphere. The conidia obtained with 26% O 2 pulses had a greater germination rate and resistance to thermal and osmotic stress, in addition to improved infectivity against Galleria mellonella (Lepidoptera) larvae. These findings were associated with an increase in catalase activities for both strains . CONCLUSION An enriched oxygen atmosphere increases the quality of conidia of both strains of I. fumosorosea , with a variable effect on conidium production. © 2013 Society of Chemical Industry