Isolamento e seleção de procariotos residentes de filoplano do tomateiro com potencial para o controle de doenças da cultura / Isolation of resident prokaryote of the tomato plant phylloplane with potential for the control of diseases of the culture

AUTOR(ES)

Roberto Lanna Filho

DATA DE PUBLICAÇÃO

2008

RESUMO

This work aimed to select tomato prokaryotic phylloplane residents for biocontrol purposes, by using Xanthomonas campestris pv. vesicatoria and Alternaria solani as challenging pathogens. Additionally, to perform a screening test using detached leaves. Consequently, leaves from healthy tomato plants were collected at Viçosa, MG and epiphytic prokaryote populations were extracted by shacking them in PBS (0,85% NaCl in 0,1M phosphate buffer saline, pH 7.0) following sonication (60Hz, 20 minutes) and serial dilution and plating in culture medium. Three hundred bacterial isolates were obtained and preserved in refrigerator, with periodical tubetube transfer, in a refrigerator. The screening was performed in two selection cycles. In the first selection in greenhouse, with three replicates per isolate and Xanthomonas campestris pv. vesicatoria as challenging pathogen, 79 isolates were able to reduce disease by 82%. In a second selection cycle, using 6 replicates per isolate, the 33 isolates were able to reduce severity by 50% in average. The 33 isolates had their antagonistic potential tested against the tomato fungal and bacterial pathogens Pseudomonas syringae pv. tomato, Pseudomonas corrugata, Xanthomonas campestris pv. vesicatoria, Clavibacter michiganensis subsp. michiganensis, Alternaria solani and Corynespora cassiicola in vitro conditions. Out of the 33 isolates, the isolate RFK-24 inhibited growth of Xathomonas campestris pv. vesicatoria, Clavibacter michiganensis subsp. michiganensis and Alternaria solani while isolate RFS-183 was able to inhibit Alternaria solani, Xanthomonas campestris pv. vesicatoria, Pseudomonas syringae pv. tomato e Pseudomonas corrugata, but none of them inhibited Corynespora cassiicola. Being RFK-24 and RFS- 183 the ones with a wider antagonistic potential out of the 33 previously selected, they were chosen for continuing the research with detached leaves and the challenging pathogens Alternaria solani e Xanthomonas campestris pv. vesicatoria. There was a positive correlation between disease severity reduction in plants the greenhouse and in detached leaves, for both antagonists. For situations involving large number of isolates to undergo mass screening, the approach with detached organs may replace the laborious and time consuming greenhouse screening.

ASSUNTO(S)

tomate pseudomonas syringae alternaria solani pests and diseases alternaria solani prokaryotes fitopatologia clavibacter michiganensis corynespora cassucola procariotos doenças e pragas xanthomonas campestris corynespora cassucola pseudomonas syringae clavibacter michiganensis xanthomonas campestris controle biológico biological control tomato

Documentos Relacionados

• Potencial de controle biológico da ferrugem do cafeeiro com bactérias residentes do filoplano
• Induction of systemic resistance in tomato by the autochthonous phylloplane resident Bacillus cereus.
• Induction of systemic resistance in tomato by the autochthonous phylloplane resident Bacillus cereus.
• Deliver and populational tendencies of the biocontrol agent Pseudomonas putida in the tomato phylloplane
• Eficiência de bactérias do filoplano no controle de doenças da parte aérea do tomateiro em condições de campo