Background and objective: Potato, the fourth important commercial crop in the world, is infected by brown rot disease, which is one of the most important bacterial plant disease worldwide. The current investigation aimed to study the influence of Saccharomyces cerevisiae on Ralstonia solanacearum and potato plant resistance to bacterial wilt disease. Methodology: The ability of S. cerevisiae to inhibit the growth of R. solanacearum in vitro was investigated. In pots experiment, potato slices were soaked in the three different treatments of S. cerevisiae (whole culture, cell-free extract and yeast cells), then cultivated in soil infested with R. solanacearum. The disease rating was recorded. Different systemic induced resistance parameters were estimated. The increase of the weight of tubers and the decrease of the percentage of infected tubers were calculated. The total count of bacteria, fungi and yeast of soil rhizosphere of potato plant were enumerated. The one-way randomized blocks design was applied in pots experiment Results: S. cerevisiae did not inhibit R. solanacearum in vitro. It was found to produce indole acetic acid, gibberellic acid and cytokinin in the amounts of 81.57, 464.56 and 4.37 µg/ml, respectively. In pots experiment, the three studied treatments of S. cerevisiae significantly increased (P ≤.0.05) the plant height and decreased the disease rating. The total phenols, flavonoids, polyphenol oxidase, peroxidase, ABTS, DPPH, reducing power and gibberellic acid were significantly increased as a response to the three studied treatments after 40 and 70 days of planting. Moreover, the antioxidant capacity and starch content were significantly increased. While sugar contents of potato tubers were significantly decreased. The rhizosphere microflora showed various responses. Conclusion It was concluded that the cell-free extract was the best treatment that could be recommended as a safe and economic bio-agent for the management of bacterial wilt disease of potato.
د زياد موسى عبد المعطي | Zeiad Moussa Abd El-Moati | 6749