Mycobiology.  2012 Jun;40(2):111-116. 10.5941/MYCO.2012.40.2.111.

Evaluation of Strains of Metarhizium anisopliae and Beauveria bassiana against Spodoptera litura on the Basis of Their Virulence, Germination Rate, Conidia Production, Radial Growth and Enzyme Activity

• Petlamul W
• Prasertsan P

• KMID: 2052899
• DOI: http://doi.org/10.5941/MYCO.2012.40.2.111

Abstract

Ten strains of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were evaluated to find the most effective strain for optimization studies. The first criterion tested for strain selection was the mortality (> 50%) of Spodoptera litura larvae after inoculation of the fungus for 4 days. Results on several bioassays revealed that B. bassiana BNBCRC showed the most virulence on mortality S. litura larvae (80% mortality). B. bassiana BNBCRC also showed the highest germination rate (72.22%). However, its conidia yield (7.2 x 10(8) conidia/mL) was lower than those of B. bassiana B 14841 (8.3 x 10(8) conidia/mL) and M. anisopliae M6 (8.2 x 10(8) conidia/mL). The highest accumulative radial growth was obtained from the strain B14841 (37.10 mm/day) while the strain BNBCRC showed moderate radial growth (24.40 mm/day). M. anisopliae M6 possessed the highest protease activity (145.00 mU/mL) while M. anisopliae M8 possessed the highest chitinase activity (20.00 mU/mL) during 96~144 hr cultivation. Amongst these criteria, selection based on virulence and germination rate lead to the selection of B. bassiana BNBCRC. B. bassiana B14841 would be selected if based on growth rate while M. anisopliae M6 and M8 possessed the highest enzyme activities.

Keyword

Beauveria bassiana; Enzyme activities; Germination rate; Metarhizium anisopliae; Radial growth; Spodoptera litura; Virulence

MeSH Terms

Beauveria
Biological Assay
Chitinase
Fungi
Germination
Larva
Metarhizium
Patient Selection
Spodoptera
Spores, Fungal
Sprains and Strains
Chitinase