Morphological Variation Of Bipolaris Isolate From The Wheat Germplasms

Abstract

Wheat is cultivated worldwide, especially at the eastern plains of south Asia, constitutes a very important
source of food to a vast population. In India, it contributes nearly 31.50% of the total food grain basket. The
investigation included the screening of 600 genotypes with a broad genetic base. A symptom of the different variant
was collected. The pathogen was isolated from different genotypes from different plant parts; variations in the
isolates were documented along with in-vitro pathogenicity testing. The morphological study of both culture and
conidia was made on half-strength PDA and water agar, respectively. Singles spore cultures were made from all
those isolates for the studies for pathogenicity. The results of the morphological study comes with the findings that
the UBS-1 (Septation: 9.1±1.3, Length: 92.2 ± 25.7, Width:49.3± 37.8) and UBS-2 (Septation:
7.6±1.7,Length:85.3±19.1,Width:33.6±19.2 ) has higher in average septation.UBS-7,UBS-9,UBS-11,UBS-12 has
triangular shape conidia. USB -9 and USB-14 has two different types of septation euseptate and distoseptate. The
result of the pathogenicity shows that out of 14 isolates, UBS -1 and UBS-2 is the most virulent isolates in in-vitro
condition and the remaining are moderately virulent and a virulent isolates. The finding comes with the variability of
the pathogen depends on the host factor and environmental factor. Different degrees of host resistance lead to
evolving new characters in the pathogen to adjust with the respective genotype and environment. From the cluster of
different isolates, it was found that the potential virulent pathogen remains consistent in-vivo. In contrast, a virulent
or moderately virulent isolate shows different degrees of virulence based on morphological and physiological
characters in a different environment.