Plant Pathology (2021) 70, 922-931

Pollyane da Silva Hermenegildo, Lúcio Mauro Silva Guimarães, Jorge Luis Badel, Abi S.A. Marques, Acelino Couto Alfenas and Marisa A.S. Velloso Ferreira (2021)
Improved evaluation of the genetic variability of Brazilian strains of Erwinia psidii with newly developed microsatellite markers
Plant Pathology 70 (4), 922-931
Abstract: Erwinia psidii is the causal agent of bacterial blight of guava, and wilt and dieback of eucalypt in Brazil. Previous studies using repetitive sequence-based PCR (rep-PCR) revealed limited genetic diversity in E. psidii populations. Here, the draft genome sequence of the type strain IBSBF435 was probed for variable number of tandem repeats (VNTRs) that could be used to study E. psidii genetic diversity by multilocus variable number of tandem repeat analysis (MLVA). Eleven selected VNTRs were used to assess genetic relatedness among 108 E. psidii strains from guava (36) and eucalypt (72), of different geographic origins and years of collection. A total of 79 haplotypes were detected in the strain collection. The number of alleles per locus ranged from 3 to 15. A minimum spanning tree indicated the occurrence of nine clonal complexes, of which two contained only guava strains, five only eucalypt strains, and two contained guava and eucalypt strains. The three oldest strains collected from guava in the 1980s (IBSBF435, IBSBF454, and IBSBF493) exhibited distinct haplotypes. IBSBF435 was genetically more closely related to some eucalypt strains than to guava strains, which supports previously reported lack of host specificity. IBSBF454 grouped with guava strains more recently collected from different states, suggesting that it could have been disseminated to different Brazilian areas. The implication of the lack of differentiation between guava and eucalypt strains is discussed in relation to the detection of E. psidii affecting eucalypt more than 25 years after the first description of guava bacterial blight.
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Link to article at publishers website
Database assignments for author(s): Acelino C. Alfenas, Marisa A.S.V. Ferreira

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Erwinia psidii	Guava (Psidium)
	Erwinia psidii	Eucalypt (Eucalyptus)