02464naa a2200181 a 450000100080000000500110000800800410001910000190006024501620007926000090024152018810025065300230213165300200215465300140217470000160218870000180220477300600222211249102016-02-25       2014    bl uuuu     u00u1 u    #d1 aMOREIRA, R. R.  aBacillus spp. and Pseudomonas putida as inhibitors of the Colletotrichum acutatum group and potential to control Glomerella leaf spot.h[electronic resource]  c2014  aThe control of Glomerella leaf spot (GLS) in Brazil is solely based on fungicide sprays and new alternatives are needed. In apple, few biological control methods have been evaluated, and most have focused on post-harvest pathogens. Therefore, the objectives of this work were to study the mode of action of three bacterial strains and the commercial product Serenade (Bacillus subtilis) against the Colletotrichum acutatum group, the causal agents of GLS, and to evaluate the influence of bacterial isolates and Serenade on the development of the first cycle of infection disease under controlled conditions. To assess the mode of action of the bacterial isolates against strains of the C. acutatum group, in vitro tests were performed. It was tested the effect of the bacteria on conidial germination and mycelial growth, using three methodologies, (i) fungal-bacterial co-cultivation, (ii) bacterial thermostable metabolites and (iii) bacterial volatile compounds. The influence of the bacterial isolates on the GLS development was assessed using apple seedlings. The seedlings were first sprayed weekly with bacterial suspension for 5 weeks, and were then inoculated with conidia suspensions (104 conidia mL1) of C. acutatum group isolates. Seedlings were maintained in chambers (CONVIRON) at 25 C and a 12-h light regime. Disease severity of GLS was evaluated daily by counting typical lesions caused by C. acutatum group on all leaves during 12 consecutive days. The disease progress curve was fitted to nonlinear models for incidence and severity data. The treatments were compared by contrasting epidemiological parameters. Bacillus sp. isolated from the apple phylloplane inhibited more than 60% of the C. acutatum group conidial germination. The mode of action of Bacillus sp. and Bacillus alcalophilus on the C. acutatum group was through the production of fixed and  aBiological control  aMalus domestica  aMonocycle1 aNESI, C. N.1 aMIO, L. L. M.  tBiological Control, Europagv. 72, n. , p. 30-37, 2014.