Submitted to: American Phytopathological Society Abstracts
Publication Acceptance Date: August 12, 1999
Publication Date: N/A
Abstract only

Technical Abstract: To explore microbial persistence and coexistence during tuber storage, colonization of tuber wounds, periderm, and eyes was monitored for dry rot biocontrol bacteria Pseudomonas fluorescens bv. V P22:Y:05 (Y05), Enterobacter cloacae S11:T:07 (T07), and P. fluorescens bv. V S11:P:12 (P12). Strains T07 and P12 also inhibit potato tuber sprouting. Tubers were inoculated with one strain or two strain combinations. Populations were monitored for 84 days. In wounds, inoculated bacteria peaked at 6.45 log cfu/cm(^2) after 7 days and gradually declined by 84 days to 4.22 log cfu/cm(^2), but initial populations of 6.21 log cfu/cm(^2) on eyes dropped to stable values of ~3 log cfu/cm(^2) after only 21 days. After 7 days, bacterial inoculants comprised 41% of wound bacteria but only 5% and 3% of eye and periderm bacteria, respectively. Inoculated singly, T07 and Y05 reached higher wound populations than P12. T07 had the highest population on eyes (P=0.05). Strain P12 had higher populations in wounds when combined with Y05 than with T07 (P=0.05). This difference in colonization success by P12 was not associated with carbohydrate or amino acid utilization profiles of the strains.