Abstract
ABSTRACT Bacterial black spot, caused by Xanthomonas campestris pv. mangiferaeindicae, is an important disease of mango (Mangifera indica). Several other plant genera of the family Anacardiaceae were described as host species for xanthomonads. We studied pathological variations among strains in a worldwide collection from several Anacardiaceae genera. Strains were classified into three pathogenicity groups. Group I strains (from the Old World) multiplied markedly in leaf tissue of mango and cashew (Anacardium occidentale). Group II strains (from Brazil) multiplied markedly in cashew leaf tissue, but not in mango. Moreover, mango leaves inoculated with group I and group II strains exhibited lesions with different morphologies, consistent with variations in symptomology previously reported on mango under field conditions. Group I strains produced black, raised lesions, consistent with the original description of the pathovar, whereas group II strains produced brownish, flat lesions. Group III strains produced a unique syndrome on ambarella (Spondias dulcis) and mombin (Spondias mombin). Based on evolutionary genome divergence derived from amplified fragment length polymorphism (AFLP) data, the three groups were genetically distinct and were related to groups 9.5, 9.6, and 9.4 of X. axonopodis identified by Rademaker, respectively. As each group was characterized by unique symptomology and/or host range, we propose that X. campestris pv. mangiferaeindicae be split into three pathovars of X. axonopodis: X. axonopodis pv. mangiferaeindicae, X. axonopodis pv. anacardii, and X. axonopodis pv. spondiae. Within pv. mangiferaeindicae sensu novo, AFLP data were consistent with that previously published for restriction fragment length polymorphism groups and suggested long-distance movement of the pathogen, likely through propagative material.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
