H.A. Mansour1, W. Nafaa2 and A.M. Mouhanna1,3*
(1) Plant Protection Department, Faculty of Agriculture, University of Damascus, Syria; (2) Faculty of Agriculture 2, Sweida Branch, University of Damascus, Syria; (3) Medical School, Syrian Private University, Syria.
*Email address of the corresponding author: [email protected]
Received: 4/1/2024; Accepted: 26/8/2024
This study aimed to use the resistance inducer BTH, and two PGPR strains “Bacillus subtillis FZB27 and Pseudomonas chlororaphis Ma342” for enhancing resistance of two tobacco cultivars (Virginia and Shak Al-Bint) to artificial infection with Peronospora hyoscyami f. sp. tabacina, which causes the downy mildew disease. Plants treated with both BTH and MA342 bacteria together showed a significant superiority over all other treatments in stimulating plant growth indicators of Virginia tobacco variety treated in both the nursery and the field, and only in the nursery, where leaves weight and area increased 98.1, 81.3, 52.8 and 42.0%, respectively, compared to the untreated control. Whereas, the same growth indicators of the local cultivar (Shak Al- Bint) plants treated with FZB27 in both the nursery and the field increased by 46.5 and 47.6%, however, such increase reached 29.1 and 29.4% for the plants treated in the nursery only, compared to the control. In both cultivars, the plants treated in both the nursery and the field showed a significant increase over the plants treated only in nursery. On the other hand, no symptoms were observed in the Virginia variety plants treated with BTH, BTH with MA342, BTH with FZB27 when treatment was carried out in the nursery and in the field. Furthermore, Virginia tobacco plants treated only in the nursery did not show any infection symptoms when treated with BTH, FZB27, or BTH + FZB27. Likewise, plants of the local cultivar (Shak Al- Bint) did not show any symptoms when treated with BTH, BTH + MA342 bacteria, BTH + FZB27 bacteria when treatment was made in both the nursery and the field. It is worth mentioning that the disease was not observed on the plants treated with BTH in the nursery.
Downy mildew, Tobacco, resistance inducers, growth parameters, Peronospora hyoscyami f. sp. tabacina
https://doi.org/10.22268/AJPP-001361