Induction of resistance in potato plants against bacterial wilt disease under Egyptian condition.
Gado E. A. M.
Author Affiliation: Plant Pathol. Dept., Fac. of Agric., Ain Shams Univ., Cairo, Egypt.
Journal of Applied Sciences Research 9 : 170-177
Abstract : Potatoes are widely cultivated in Egypt. This crop considers one of the most important vegetable either for local consumption and exportation. Bacterial wilt causing by Ralstonia solanacearum became endemic in Egyptian soil awing to the ability of such bacteria to hebetate as saprophyte and parasite on many plants. This study was carried out to find out any chemical or natural agent could induce resistance in potato plant against these bacteria as preplanted tuber treatment. In this respect water solution of plant material extracts and chemical agents were tested either in pots or under field conditions. Data obtained clear by indicated that bacterial infection led to dramatic decrease of plant productivity (determined as No. of tuber/plant and total weight of such tuber/plant). All tested agents reduced disease incidence on plant foliage and also decreased the percentage of affected tubers (visible and latent infection). Jasmonic acid treatment decreased disease severity from 36.6% to 10.9% followed by coconut milk solution, mango malformed inflorescence extract, ethyl salicylic acid, Agrispon® and Sincocin® in descending order. Under field condition, Jasmonic acid came in the priority followed by coconut milk. Both agents significantly reduced infection of yield tubers. In peels of tubers previously treated by tested agents, isozymes of soluble peroxidase were electrophoretically separated. In control tubers (treated by water) only two bands (p1 and p2), Sincocin® led to elicitation of third band (p3). Other tested agents elicited additional bands (P1, P2, P3 and P4) the obtained results revealed that tested agents elicit additional peroxidase bands in treated potato tuber peels which may affect bacterial penetration of tuber wound or natural openings.