Population dynamics of Erwinia carotovora subsp. atroseptica on the surface of intact and wounded seed potatoes during storage.
Vuurde, J.W.L. van. and De Vries, P. M.
The Journal of Applied Bacteriology. Volume 76, Number 6, June 1994. Pages 568-575.
1994
บทคัดย่อ
Population dynamics of Erwinia carotovora subsp. atroseptica (Eca) on the tuber surface during storage (2-4 degrees C) and pregermination, were studied by plating extracts of 6 mm2 point samples on crystal violet pectate medium. To investigate the effect of harvest damage on Eca survival, intact, skinned (epidermis removed), and peeled (complete peel removed) tubers from a dry (pF 3.4) and from a wet (pF 2.0) soil were inoculated either immediately after harvesting or after air drying for 4 h. Eca numbers on intact tuber surface decreased rapidly after inoculation, whereas at the skinned and peeled surface numbers were significantly increased 2 d after harvest. Tubers peeled and inoculated with Eca were rotted by 2 d after harvest while tubers peeled and dried before inoculation did not rot; however, populations were significantly increased 2 d after harvest. For all treatments Eca numbers per point sample decreased to below detection limits 180 d after harvest. Examination of 600 mm2 surface samples of the various treatments 222 d after harvest showed that Eca populations were still present. The number of tubers contaminated with colony-forming units (cfu) of Eca was significantly lower for intact surface inoculated tubers from dry soil than for those of the other treatments. Drying for 4 h before inoculation resulted in a significant reduction of the number of Eca cfu positive tubers compared to all other treatments. The ELISA OD values of the 600 mm2 surface samples at day 222 were almost all positive and showed only a slight difference between the average of the tubers containing culturable Eca cells and those without culturable Eca cells.