AUTHOR=Brauna-Morževska Elīna , Stoddard Frederick L. , Bankina Biruta , Kaņeps Jānis , Bimšteine Gunita , Petrova Irina , Neusa-Luca Ingrīda , Roga Ance , Fridmanis Dāvids 

TITLE=Evaluation of pathogenicity of Botrytis species isolated from different legumes

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1069126

DOI=10.3389/fpls.2023.1069126

ISSN=1664-462X

ABSTRACT=<p>Fungi of genus <italic>Botrytis</italic> are important pathogens of legumes, causing gray mold and chocolate spot diseases. The use of molecular methods to identify pathogens has resulted in the discovery of several new <italic>Botrytis</italic> species and new associations of pathogens with diseases. Thus, chocolate spot of faba bean is now associated with at least four species: <italic>B. fabae</italic>, <italic>B. cinerea</italic>, <italic>B. pseudocinerea</italic> and <italic>B. fabiopsis</italic>. Species of <italic>Botrytis</italic> differ in host plant, pathogenicity, fungicide resistance and other relevant properties that affect disease control. The aim of this study was to identify the species of <italic>Botrytis</italic> isolated from different legume crops and to evaluate their <italic>in vitro</italic> pathogenicity. Between 2014 and 2019, 278 isolates of <italic>Botrytis</italic> were obtained from infected legumes in Latvia. A phylogenetic analysis was carried out by sequencing three nuclear genes, RPB2, HSP60, and G3PDH, considered to be diagnostic for species in this genus. A set of 21 representative isolates was selected for pathogenicity tests on detached leaves of faba bean, field pea, lupin and soybean using 5-mm mycelium-agar plugs. The diameter of the formed lesions under the inoculated plug was measured crosswise each day. The datasets were subjected to analysis of variance with the split-plot design of the experiment and repeated-measures model. Six species were identified: <italic>B. cinerea</italic>, <italic>B. fabae</italic>, <italic>B. pseudocinerea</italic>, <italic>B. fabiopsis</italic>, <italic>B. euroamericana</italic> and <italic>B. medusae</italic>. In addition to the expected combinations of host and pathogen, naturally occurring infections of <italic>B. fabiopsis</italic> were found on chickpea, <italic>B. euroamericana</italic> on faba bean and <italic>B. medusae</italic> in lupin seeds. Species and isolate had significant effects on pathogenicity on all crops tested. Several isolates were pathogenic on two or more host species: two of <italic>B. pseudocinerea</italic>, two of <italic>B. cinerea</italic>, two of <italic>B. fabiopsis</italic> and the one of <italic>B. medusae</italic>. One isolate of <italic>B. pseudocinerea</italic> and two of <italic>B. fabiopsis</italic> caused primary lesions on all five host species. The results show that these <italic>Botrytis</italic> species have a broad host range that should be borne in mind when planning crop sequences and rotations.</p>