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Characterization of Isolates of Bacterial Blight of Cotton ( Xanthomonas campestris pv. malvacearum ) from Nicaragua
Author(s) -
Zachowski A.,
Rudolph K.
Publication year - 1988
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/j.1439-0434.1988.tb04486.x
Subject(s) - xanthomonas campestris , biology , bacterial blight , inoculation , pathogen , cultivar , germination , horticulture , bacteria , spots , xanthomonas , xanthomonas campestris pv. campestris , bacterial disease , botany , microbiology and biotechnology , biochemistry , genetics , gene
Seeds from cotton plants infected with Xanthomonas campestris pv. malvacearum were collected in different parts of Nicaragua in 1986. When the seeds were homogenized the pathogen could not always be identified by dilution plating. Therefore, an enrichment of bacteria on the natural host was induced before isolation. The cotton seeds were shaken with water and sand for 2 days and then sown in sand for germination. Rather often the developing cotyledons showed typical water‐soaked spots, from which the pathogen could be isolated easily. This new method needed more time but made it possible to detect a low level of bacterial infestation. Altogether, 42 bacterial isolates were obtained. For inoculation experiments suspensions with 5x10 5 CFU ‐ ml −1 were infiltrated into cotton leaves. Incubations of inoculated plants in growth chambers, but not in greenhouses, resulted in typical and uniform disease symptoms (water‐soaked leaf spots). Nine of the ten cotton differentials tested were highly susceptible to all the 42 bacterial isolates. Since only line 101‐102B proved to be resistant, the Nicaraguan isolates of bacterial blight of cotton were characterized as race 18, of the pathogen. The main cotton cultivars grown in Nicaragua (H‐373 and G‐286) were strongly affected by the isolated bacterial strains. In order to reduce the disease incidence in Nicaragua, the cultivation of resistant cotton varieties is suggested.