AUTHOR=Ivanović Žarko , Blagojević Jovana , Jovanović Gordana , Ivanović Borko , Žeželj Danica 

TITLE=New Insight in the Occurrence of Early Blight Disease on Potato Reveals High Distribution of Alternaria solani and Alternaria protenta in Serbia

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.856898

DOI=10.3389/fmicb.2022.856898

ISSN=1664-302X

ABSTRACT=<p>Early blight is an economically important disease of potato worldwide. Understanding which fungal pathogens are the causal agents of early blight and their distribution on the same host is essential to finding the best strategy for the control of this disease. Previous studies have shown that <italic>Alternaria solani</italic> is the main early blight pathogen parasitizing potato. Here, we analyzed genetic and phenotypic diversity in isolates of <italic>Alternaria</italic> spp. covering all potato production areas in Serbia. We showed that the four species of <italic>Alternaria</italic> were found in areas with different distributions of the species. The occurrence of <italic>Alternaria</italic> spp. was studied by analyzing isolates from symptomatic potato leaves during multiyear sampling. In addition to <italic>Alternaria solani,</italic> we detected three more large-spored species identified as <italic>A. linariae</italic> (syn. <italic>A. tomatophila</italic>), <italic>A. protenta,</italic> and <italic>A. grandis</italic> that were involved in early blight disease on naturally infected potato leaves in Serbia. Differentiation of species was supported by phylogeny obtained from the DNA sequences of the <italic>GAPDH</italic>, <italic>calmodulin</italic> and <italic>Rpb2</italic> genes. Our findings present a new perspective into the population structure of large-spored <italic>Alternaria</italic> species associated with early blight disease. Within the groups of large-spored <italic>Alternaria</italic> present in Serbia, evidence of <italic>A. protenta</italic> at high frequency reveals new insight into the contribution of <italic>Alternaria</italic> species in early blight disease. This work opens new perspectives for early blight management, while the distribution of different species on the same host suggests that the etiology of disease could depend on crop organization and the presence of other <italic>Alternaria</italic> hosts in close proximity to potato plants.</p>