Limanska N, Korotaeva N, Biscola V, Ivanytsia T, Merlich A, Franco BDGM, Chobert JM, Ivanytsia V and Haertlé T
Inhibition of crown gall on test plants in case of co-inoculation with lactic acid bacteria (LAB) has been investigated. From nine LAB strains tested, eight reduced amount of galled carrot explants by 36.4-87.7% and decreased the intensity of disease manifestation. The antagonistic activity against Agrobacterium tumefaciens, in vitro, was due to the low pH of organic acids produced by LAB. However, in the same pH, different LAB cultures displayed various levels of inhibition in vivo. Lactobacillus plantarum ONU 12 with the best results in tumor inhibition on carrots, showed high antagonistic activity on surfaces of kalanchoe and grapevines. Depending on the method of inoculation, the culture of L. plantarum ONU 12 could protect from 72.7% to 100% of wounded kalanchoe tissues. Evaluation of number of surviving cuttings and amount of buds that grew indicated that co-inoculation with agrobacteria and LAB removed completely the negative influence of phytopathogen on grapevines and reduced the number of infected cuttings by approximately 80%. One-hour treatment with L. plantarum ONU 12 helped to decrease the number of infected plants by approximately 68%. The studied strain L. plantarum ONU 12 can be proposed for further evaluation of possibility of practical use in plant protection.