GENETIC DIVERSITY OF ERWINIA AMYLOVORA STRAINS DETERMINED BY DNA POLYMORPHISMS AMPLIFIED BY PCR USING ARBITRARY PRIMERS

The genetic diversity among 16 strains of Erwinia amylovora, chosen to represent different geographic regions and host plant origins, was assessed by RAPD analysis.
One strain of Erwinia herbicola and one of Agrobacterium vitis were used as outgroups.
Six ten-mer primers resulted in the detection of 98 different RAPD fragments.
RAPD banding profiles were found that enabled all 16 of the E. amylovora strains to be distinguished from one another.

Nei-Li similarity coefficients were computed for every pair of strains from data on fragment presence or absence.
Relatedness between strains was evaluated by UPGMA clustering.
Strains of E. amylovora isolated from the subfamily Pomoideae formed a single group.
Two strains from Rubus (subfamily Rosoideae) formed a second group.
Two strains isolated from Asian pear in Japan (Hokkaido) formed a third group.
Sets of RAPD fragments were identified that enabled each of the three groups to be unambiguously distinguished from one another and from the outgroups.

Based on these results the level of heterogeneity within E. amylovora should be examined more extensively using additional strains in RAPD analysis, and other molecular, biochemical and host range tests.
This study shows that RAPD analysis is a useful technique to identify individual strains of E. amylovora and to study their relatedness.

VII International Workshop on Fire Blight

M.T. Momol, E.A. Momol, J.L. Norelli, H.S. Aldwinckle, S.V. Beer, W.F. Lamboy

https://doi.org/10.17660/ActaHortic.1996.411.56