AUTHOR=Armstrong-Cho Cheryl , Sivachandra Kumar Nimllash Thangam , Kaur Ramanpreet , Banniza Sabine 

TITLE=The chickpea root rot complex in Saskatchewan, Canada- detection of emerging pathogens and their relative pathogenicity

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1117788

DOI=10.3389/fpls.2023.1117788

ISSN=1664-462X

ABSTRACT=<p>Chickpea fields in Saskatchewan, one of the three Canadian prairie provinces, have suffered from major health issues since 2019, but no definitive cause has been determined. Field surveys were conducted in Saskatchewan in 2020 and 2021 in order to develop a better understanding of root rot pathogens associated with chickpea. Root samples were analyzed for the presence of 11 potential chickpea root rot pathogens using end-point PCR. <italic>Fusarium redolens</italic>, <italic>F. solani</italic> and <italic>F. avenaceum</italic> were the most prevalent pathogen species detected in both survey years. The cause of Fusarium wilt in chickpea, <italic>F. oxysporum</italic> f. sp. <italic>ciceris</italic>, was not detected in either year, nor were <italic>Phytophthora</italic> spp. and <italic>Verticillium albo-atrum</italic>. <italic>Berkeleyomyces</italic> sp. was detected in one field in each year, and <italic>Verticillium dahliae</italic> was detected in several fields sampled in 2021. These two pathogens have not been reported previously on chickpea in Saskatchewan. The prevalence of <italic>Fusarium</italic> species obtained from 2021 root isolations was similar to that determined by molecular tests, with frequent isolation of <italic>F. redolens</italic>, <italic>F. oxysporum</italic>, <italic>F. avenaceum</italic> and <italic>F. solani</italic>. A series of indoor pathogenicity testing compared root disease severity caused by a selection of 16 isolates of six <italic>Fusarium</italic> species and single isolates of <italic>V. dahliae</italic>, <italic>Berkeleyomyces</italic> sp. and <italic>Macrophomina phaseolina</italic>. Results showed that select isolates of <italic>F. avenaceum</italic> were the most aggressive of the <italic>Fusarium</italic> isolates on chickpea. Despite relatively low inoculum density, a highly aggressive isolate of <italic>F. avenaceum</italic> caused severe stunting and more root rot symptoms than single isolates of <italic>V. dahliae</italic>, <italic>Berkeleyomyces</italic> sp. and <italic>M. phaseolina</italic> under the test conditions.</p>