Morphology, Physiology, and Virulence of Bipolaris sorokiniana Isolates

Abstract

Bipolaris sorokiniana is a phytopathogenic fungus that causes diseases in cereal crops. The high morphological, physiological, and genetic variability makes the control of this fungus a difficult task. The aim of this work was to study the virulence, morphological, and physiological variability of B. sorokiniana isolates. For this, 35 B. sorokiniana isolates from different geographic regions in Brazil and other countries were used. The isolates were evaluated for their morphological variability, considering mycelium color, sector formation, and growth rate. Based on these morphological characteristics, the isolates were grouped in five different morphological groups. Extracellular enzymes activity in solid medium, virulence in wheat seeds and seedlings, and analysis of total proteins by SDS-PAGE were evaluated for all isolates. Variations among the isolates were found for enzymatic activity, and esterase was the enzyme that showed the highest activity indices. The results obtained from infection of seeds and seedlings showed that isolates from the same geographical region and morphological group had different degrees of virulence. The total protein profile shown by the isolates varied in the number of bands and intensity, where some of them may be used to characterize the specie.

Evaluation of certain Penicillium frequentans isolates against Cercospora leaf spot disease of sugar beet

“…Inoculated plates were incubated at 25°C for one week. Pectinolytic and cellulolytic activities were determined by averaging diameters of clear zones around fungal colonies (Poloni et al 2009). …”

Morphological, pathological and genetic variations among isolates of Cochliobolus sativus from Nepal

“…A high morphological variability among isolates of C. sativus has been reported from South America (Oliveira et al 1998;Poloni et al 2009). The 35 isolates of C. sativus from Brazil (n028), Mexico (n04), Bangladesh (n01), Denmark (n01) and Vietnam (n01) were classified into five morphological groups based on the mycelia colour, sector formation, and growth rate on culture medium (Poloni et al 2009). High pathological variability among isolates of C. sativus has been previously reported (Ghazvini and Tekauz 2007;Oliveira et al 1998;Poloni et al 2009;Valjavec-Gratian and Steffenson 1997;Zhong and Steffenson 2001).…”

“…Morphology of C. sativus has been characterized on the basis of colony colour and growth patterns such as zonation, sectoring, and mycelia colour (Jaiswal et al 2007;Pandey et al 2008). A high morphological variability among isolates of C. sativus has been reported from South America (Oliveira et al 1998;Poloni et al 2009). The 35 isolates of C. sativus from Brazil (n028), Mexico (n04), Bangladesh (n01), Denmark (n01) and Vietnam (n01) were classified into five morphological groups based on the mycelia colour, sector formation, and growth rate on culture medium (Poloni et al 2009).…”

“…Morphological, pathological and molecular approaches have been used to identify and investigate the variability among isolates of C. sativus (Ghazvini and Tekauz 2007;Jaiswal et al 2007;Oliveira et al 1998;Poloni et al 2009;Valjavec-Gratian and Steffenson 1997;Zhong and Steffenson 2001). Morphology of C. sativus has been characterized on the basis of colony colour and growth patterns such as zonation, sectoring, and mycelia colour (Jaiswal et al 2007;Pandey et al 2008).…”

“…The 35 isolates of C. sativus from Brazil (n028), Mexico (n04), Bangladesh (n01), Denmark (n01) and Vietnam (n01) were classified into five morphological groups based on the mycelia colour, sector formation, and growth rate on culture medium (Poloni et al 2009). High pathological variability among isolates of C. sativus has been previously reported (Ghazvini and Tekauz 2007;Oliveira et al 1998;Poloni et al 2009;Valjavec-Gratian and Steffenson 1997;Zhong and Steffenson 2001). Genetic structure of C. sativus has been investigated using random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP) and URP-based primers (Aggarwal et al 2009;Jaiswal et al 2007;Zhong and Steffenson 2001).…”