Kirkuk University Journal For Agricultural Sciences

Abstract

Quantitative propagation of two local fungal isolates; Beauveria bassiana، Metarhizium anisopliae، improvement their bio-efficacy by ultra-violet irradiation was carried out in this study.The results showed the increase in the irradiation time affected negatively on the studied fungi growth. The un-irradiated conidia showed a high growth rate compared to irradiated conidia. The number of un-irradiated B.bassiana and M.anisopliae conidia was 159.01×102 /ml and 11.58×102/ml, respectively, then the colonies growth significantly decreased at irradiation time 15-105 min, while there is no growth in irradiated conidia at 120 min. The results showed, the highest percentage of mortality began at the first irradiation time in both fungi, resulting in 98.1 and 95.9% after 15 min. then the percentage of mortality was 100% at 120 min. The survival fungal strains are regarded as mutants owing to their variation in morphology, physiology and enzymology, the results showed the highest protease activity recorded in all B.bassiana mutants (except in B15-2,B30-1,B60-3,B75-3 and B90-2) .The mutant B105-1 showed highest protease activity which was 34.9 unit/ml compared to 14.86 unit/ml in control, in addition, all M.anisopliae mutants record high protease activity compared to wild strain, the highest protease was 7.16 and 7.05 unit/ml in mutants M30-2 and M45-2, respectively, compared to 4.6 unit/ml in wild strain. The result also showed increase in chitinase activity in all mutants. The highest activities were 0.34 and 0.7 unit/ml in mutants B105-1 and M75-2 compared to 0.09 and 0.11 unit/ml in wild B.bassiana and M.anisopliae, respectively.In compatibility study of insecticides Difuse and Matrixin (at recommended concentration) with wild and mutant strains, the results showed superior of all B.bassiana mutants growth in present of Difuse (except B15-2،B30-1 and B60-1) compared to wild strain. The highest growth was in mutants B105-3, B60-3 and B60-2 resulting in 84,85 and 84 mm, respectively, the results showed the effect of Matrixin Plus, was more than Difuse, however, the growth of all B.bassiana mutants was higher than wild strain which result lower growth (41.5 mm) while the highest growth was 59.5 and 60 mm in B90-2 and B105-3 ، respectively، while the M.anisopliea mutants, M15-2, M30-1, M30-3, M45-2, M45-3, M75-2, M75-3 and M90-3 showed highest growth reached to 85 mm in the present of Difnse without significant differences compared to control while both mutants M30-1 and M45-2 showed highest growth resulting in 85 and 84.16 mm in the present of Matrixin plus without significant differences compared to control.The results of evaluation of vitality of wild and mutants of B.bassiana and M.anisopliea when to grow in various media in store temperatures 30 oC,40 oC and 50oC showed the significant superior of B105-1 mutant growth compared to all other mutants،in which the number of colonies were 232,100 and 54×105 colony/gm, when stored at 30 days in rice hulls،wheat bran and Maize, respectively. The same mutant showed higher growth 208.6×105 colony/gm when stored at 50oC in rice hulls after 60 days. The mutant M15-2 of M.anisopliea recorded highest growth when stored for 30 days at 30 oC and 40oC in millet resulting in 833 and 443×106 colony/gm، the same mutant recorded highest growth 356×106 colony/gm، after stored for 60 days at 30oC