TITLE:
Biological Control of Erwinia carotovora ssp. carotovora by Streptomyces Species
AUTHORS:
Tinatin Doolotkeldieva, Saykal Bobusheva, Ayzat Suleymankisi
KEYWORDS:
Potato Tubers, Soft Rot Disease, Erwinia carotovora ssp. carotovora, Biological Control, Streptomyces diastatochromogenes
JOURNAL NAME:
Advances in Microbiology,
Vol.6 No.2,
February
24,
2016
ABSTRACT: Ten isolates of Erwinia carotovora ssp. carotovora (Ecc) were isolated from infected
potato tubers of Picasso, Sante, and Nevskiy varieties collected from different
regions in Kyrgyzstan. Isolates were identified as Erwinia carotovora ssp. carotovora (Ecc) by
standard bacteriological techniques and pathogenicity tests on tubers and also
by PCR analyses. Tests on the pathogenicity of E. carotovora ssp. carotovora (Ecc)
strains to host plants by artificial inoculation have shown a high sensibility
of the Picasso variety. As a result, five isolates were chosen, three isolates
(EcPo1, EcPo2, and Eco3) were highly pathogenic, while two
isolates (Eco4 and Eco5) were weakly pathogenic. The antagonistic
bacteria, Streptomyces diastatochromogenes strain sk-6, and Streptomyces
graminearuss strain sk-2, have
a highly significant effect on soft rot bacteria isolates (Ecc), more
than the other tested antagonistic organisms in vitro screening biotests. The Streptomyces diastatochromogenes
sk-6 was selected for the control assay of storage potatoes against the
most common soft rot bacterial strain in Kyrgyzstan, Erwinia carotovora sp. carotovora EcPo2. The
pretreatment of potato tubers with antagonistic bacteria successfully prevented
the initial infection multiplication of soft rot bacteria and reduced soft rot
disease of potatoes in storage. These results justify selection of the dose 106 cells/ml of bacteria Streptomyces diastatochromogenes sk-6 for use in powdering the infected
or non-infected potato tubers to suppress the development soft rot during
storage. Streptomyces diastatochromogenes sk-6 as a biological disinfectant could destroy surface and
internal infections, protect the tubers from the growth of phytopathogenic
bacteria in the early period of their reproduction, and improve the
overwintering of winter crops.