Bacterial extracts and bioformulates as a promising control of fruit body rot and root rot in avocado cv. Hass  

作　　者：David GRANADA Lorena LÓPEZ-LUJAN Sara RAMIREZ-RESTREPO Juan MORALES Carlos PELÁEZ-JARAMILLO Galdino ANDRADE Juan Carlos BEDOYA-PEREZ 

机构地区：[1]Phytosanitary and Biological Control Unit,Corporation for Biological Research,Medellin 050034,Colombia [2]Faculty of Health Sciences,Institution University Colegio Mayor de Antioquia,Medellin 050034,Colombia [3]Department of Agronomic Sciences,National University of Colombia,Medellin 050034,Colombia [4]Faculty of Exact Sciences,University of Antioquia,Medellin 050010,Colombia [5]Department of Microbiology,Londrina State University,Londrina 86051-990,Brazil

出　　处：《Journal of Integrative Agriculture》2020年第3期748-758,共11页农业科学学报（英文版）

基　　金：the Faculty of Health Sciences from the Institution University Colegio Mayor de Antioquia and the General System of Royalties from Antioquia,Colombia,for funding this project;the National University of Colombia and the Doctoral Fellowship Program(567)from Colciencias

摘　　要：At least 20-40% of annual losses of avocado crops are caused by pathogenic fungi.The chemical treatments of these diseases are inefficient,cause environmental pollution and are increasingly restricted by international laws.This work aimed to assess the biocontrol capacity of a bacterial extract to protect avocado fruits and plants from pathogen infections.Extracts from the bacterial isolate Serratia sp.ARP5.1 were obtained from liquid fermentations in a biorreactor.A body rot postharvest infection model with Colletotrichum gloeosporioides on fruits was developed.Moreover,packaging conditions were simulated using the bacterial extract and the commercial fungicide prochloraz as a positive control.Additionally,seedlings infections with Phytophthora cinnamomi were performed on two types of avocado(West Indian race and cv.Hass).The Area Under Disease Progress Curve(AUDPC) was recorded using the bacterial extract and a commercial product with fosetyl-aluminium as treatments.The bacterial extract significantly reduced infections by C.gloeosporioides on injured avocado fruits at 31.1 μg mL^-1.Intact fruits were also protected against body rot infections at the same concentration and showed no significant differences with the commercial fungicide.On the other hand,AUDPC in the seedlings was significantly reduced with the extract treatment at 3 μg mL^-1 compared to the control.However,a possible phytotoxicity effect of the extract was evidenced in the seedlings and confirmed by pathogen recovery and tests on Raphanus sativus seedlings.Finally,formulations of the extracts(emulsion and emulsifiable concentrate) were prepared,and bioactive stability was assessed for 8 wk.The emulsion formulates demonstrated very stable bioactivity against P.cinnamomi.The extract and the emulsion formulate showed promising results for the control of avocado pathogens.New bioproducts based on this type of active principles could be developed for the benefit of avocado industry.At least 20–40% of annual losses of avocado crops are caused by pathogenic fungi. The chemical treatments of these diseases are inefficient, cause environmental pollution and are increasingly restricted by international laws. This work aimed to assess the biocontrol capacity of a bacterial extract to protect avocado fruits and plants from pathogen infections. Extracts from the bacterial isolate Serratia sp. ARP5.1 were obtained from liquid fermentations in a biorreactor. A body rot postharvest infection model with Colletotrichum gloeosporioides on fruits was developed. Moreover, packaging conditions were simulated using the bacterial extract and the commercial fungicide prochloraz as a positive control. Additionally, seedlings infections with Phytophthora cinnamomi were performed on two types of avocado(West Indian race and cv. Hass). The Area Under Disease Progress Curve(AUDPC) was recorded using the bacterial extract and a commercial product with fosetyl-aluminium as treatments. The bacterial extract significantly reduced infections by C. gloeosporioides on injured avocado fruits at 31.1 μg mL–1. Intact fruits were also protected against body rot infections at the same concentration and showed no significant differences with the commercial fungicide. On the other hand, AUDPC in the seedlings was significantly reduced with the extract treatment at 3 μg mL–1 compared to the control. However, a possible phytotoxicity effect of the extract was evidenced in the seedlings and confirmed by pathogen recovery and tests on Raphanus sativus seedlings. Finally, formulations of the extracts(emulsion and emulsifiable concentrate) were prepared, and bioactive stability was assessed for 8 wk. The emulsion formulates demonstrated very stable bioactivity against P. cinnamomi. The extract and the emulsion formulate showed promising results for the control of avocado pathogens. New bioproducts based on this type of active principles could be developed for the benefit of avocado industry.

关 键 词：Colletotrichum gloeosporioides Phytophthora cinnamomi Serratia sp. antagonistic microbes secondary metabolites BIOFUNGICIDE 

分 类 号：S436.67[农业科学—农业昆虫与害虫防治]