Morphological Characterization of Native Isolates of Hypocreale Fungi Metarhizium rileyi (Farl.) Samson from Maize Fall Armyworm

Abstract

The Present studies indicates the collection of entomopathogenic fungi from the roving survey in Northeastern region of Karnataka, India to know the diversity of M. rileyi distribution and also its growth pattern. Different morphological parameters used for describing the growth pattern which indicates diversity and uniqueness of M. rileyi i.e., colony colour which was white during initial stage and then during sporulating stage the colour changed into malachite green colour. The conidiophores were in compact patches. Conidia were aseptate, hyaline, round or ovoid in shape and elongate by forming chains. Conidiophores were short, which bears round to ovoid aseptate conidia in different isolates. The conidia size on its ratio found that, the highest size ratio was recorded in UASRBC Mr-20 2.19 then remaining isolates which has shown less than 2.0. The radial growth found only in Mr-20 and Mr-22nd Isolates, colony diameter ranged from 0.3 to 2.23 cm, concentric rings of colonies found in all the isolates except Mr-19 and Mr-20th isolates. The colony surface layer was white cottony growth to pale yellow color was found in all the isolates, the colony pigmentation in most of the isolates was light brown colored pigmentation. The growth appearance was irregular patchy growth was observed in most of the isolates. Among six different isolates the highest width was recorded in isolate UASRBC Mr-20 (6.46) followed by UASRBC Mr-22 (5.73) which was significantly superior than remaining isolates. The highest colony diameter was recorded in UASRBC Mr-18 (19 mm).