scholarly journals Antagonistic potential of native agrocin-producing non-pathogenic Agrobacterium tumefaciens strain UHFBA-218 to control crown gall in peach

2017 ◽  
Vol 97 (1) ◽  
pp. 1-11
Author(s):  
Aditi Sharma ◽  
A. K. Gupta ◽  
K. Khosla ◽  
Rishi Mahajan ◽  
Bharti ◽  
...  
Keyword(s):  
Biological Control ◽  
Agrobacterium Tumefaciens ◽  
Crown Gall ◽  
Room Temperature ◽  
Biological Control Agent ◽  
Control Agent ◽  
Stone Fruits ◽  
Copper Oxychloride ◽  
Antagonistic Potential ◽  
Different Doses

A non-pathogenic agrocin-producing native isolate ofAgrobacterium tumefaciensstrain UHFBA-218 was tested as a biological control agent against the peach crown gall. This strain was compatible with all the recommended pesticides used in stone fruits in the integrated pest management (IPM) module, except for copper oxychloride, which was detrimental to its growth. Upon artificial co-inoculation of 4-wk-old plants of tomato var. Solan Gola withA. tumefaciensstrain UHFBA-218 and tumorigenicA. tumefaciensstrain Peach 2E-10, out of the 27 isolates recovered, six were transconjugants showing selective acquisition of tumorigenic factors as made evident by amplification withiptandvirD2primers, whereas the rest of the isolates did not acquire any of these tumorigenic factors. A white stone powder-based formulation of this isolate (103.3 × 108cfu g-1) retained appreciable viability for up to 6 months at room temperature. When peach roots and seeds were soaked in cell suspensions of different doses of a white stone powder-based bioformulation of UHFBA-218 before planting in the field, the number of plants with tumours was reduced, with the lowest incidence of crown gall being observed in the 0.1% UHFBA-218 root dip treatment, i.e. 1.48% and 0.80% during the years 2013 and 2014, respectively. No incidence of crown gall was observed in the three seed dip treatments, i.e. 30-min dip in UHFBA-218 followed by 1 h of shade drying, stratified seeds dipped for 30 min in 0.1% suspensions of strains UHFBA-218 or K84 followed by 1 h of shade drying before sowing, as compared with 14.76% incidence in untreated plants.

scholarly journals Effects of Wounding, Inoculum Density, and Biological Control Agents on Postharvest Brown Rot of Stone Fruits

Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1210-1216 ◽  
Author(s):  
Chuanxue Hong ◽  
Themis J. Michailides ◽  
Brent A. Holtz
Keyword(s):  
Biological Control ◽  
Biocontrol Agent ◽  
Biological Control Agent ◽  
Brown Rot ◽  
Control Agent ◽  
Inoculum Density ◽  
Stone Fruits ◽  
Trichoderma Spp ◽  
Further Development ◽  
Spore Load

The effects of wounding, inoculum density, and three isolates (New, Ta291, and 23-E-6) of Trichoderma spp. and one isolate (BI-54) of Rhodotorula sp. on postharvest brown rot of stone fruits were determined at 20°C and 95% relative humidity (RH). Brown rot was observed frequently on wounded nectarine, peach, and plum fruits inoculated with two spores of Monilinia fructicola per wound, and occasionally on unwounded nectarine and peach fruits inoculated with the same spore load. Brown rot was observed on wounded plums only. A substantial increase in lesion diameter of brown rot was also recorded on wounded nectarines and peaches inoculated with suspensions of ≤20 spores and ≤200 spores per wound, respectively, compared with unwounded fruit. At concentrations of 107 and 108 spores per ml, all Trichoderma isolates substantially reduced brown rot on peaches (63 to 98%) and plums (67 to 100%) when fruits were inoculated with M. fructicola following the application of a biological control agent. Similarly, at 108 spores per ml, the yeast BI-54 also suppressed brown rot on peaches completely and on plums by 54%. Significant brown rot reduction was also achieved with the isolate New at a concentration of 108 spores per ml, even when the biocontrol agent was applied 12 h after inoculation with M. fructicola and under continuous conditions of 95% RH. The isolates Ta291 and 23-E-6 also reduced brown rot significantly under drier (50% RH) incubation conditions. These isolates provided the best control of brown rot on plums when they were applied 12 h earlier than inoculation with M. fructicola. Satisfactory control of brown rot on plums inoculated with M. fructicola at 8 × 104 spores per ml was achieved with New at 106 spores per ml and with Ta291 at 107 spores per ml. Measures taken to avoid injuring fruit will greatly reduce brown rot of stone fruit at any spore load for plum, but only at ≤50 spores per mm2 for peach, and at ≤5 spores per mm2 for nectarine. This study identifies two isolates (Ta291 and New) of Trichoderma atroviride, one isolate (23-E-6) of T. viride, and one of Rhodotorula sp. that show potential for further development as biocontrol agents of postharvest brown rot of stone fruits.

scholarly journals Complete Genome Sequence Data of Nonpathogenic Strain Rhizobium vitis VAR03-1, a Biological Control Agent for Grapevine Crown Gall Disease

2020 ◽  
Vol 33 (12) ◽  
pp. 1451-1453
Author(s):  
Yoshiteru Noutoshi ◽  
Atsushi Toyoda ◽  
Tomoya Ishii ◽  
Kirara Saito ◽  
Megumi Watanabe ◽  
...  
Keyword(s):  
Biological Control ◽  
Genome Sequence ◽  
Crown Gall ◽  
Complete Genome ◽  
Sequence Data ◽  
Biological Control Agent ◽  
Suppressive Effect ◽  
Control Agent ◽  
Crown Gall Disease ◽  
Nonpathogenic Strain

Crown gall disease in grapevine is caused by pathogenic strains of Rhizobium vitis with a tumor-inducing (Ti) plasmids. A nonpathogenic strain, VAR03-1 of R. vitis, has been isolated from the grapevine root of nursery stock and it was shown to act as a biological control agent to crown gall disease. Its disease-suppressive effect was observed even when it was coinoculated with the pathogen in a 1:1 ratio. Here, we present the complete genome data of R. vitis VAR03-1, assembled by sequencing reads obtained by both PacBio and Illumina technologies with annotation. This genome sequence could contribute to investigations of the molecular basis underlying the biocontrol activity as well as the root-colonization ability of this bacterial strain. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Biological Control of Crown Gall of Grapevine, Rose, and Tomato by Nonpathogenic Agrobacterium vitis Strain VAR03-1

2008 ◽  
Vol 98 (11) ◽  
pp. 1218-1225 ◽  
Author(s):  
A. Kawaguchi ◽  
K. Inoue ◽  
Y. Ichinose
Keyword(s):  
Biological Control ◽  
Crown Gall ◽  
Biological Control Agent ◽  
Inhibitory Effect ◽  
Control Agent ◽  
Inhibitory Effects ◽  
Agrobacterium Vitis ◽  
Colony Forming Units ◽  
Nonpathogenic Strain ◽  
A Cell

A nonpathogenic strain of Agrobacterium vitis VAR03-1 was tested as a biological control agent for crown gall of grapevine (Vitis vinifera). When roots of grapevine, rose (Rose multiflora), and tomato (Lycopersicon esculentum) were soaked in a cell suspension of antagonists before planting in soil infested with tumorigenic A. vitis, A. rhizogenes, and A. tumefaciens, respectively, treatment with VAR03-1 significantly reduced the number of plants with tumors and disease severity in the three plant species. The inhibitory effects of treatment with VAR03-1 and the nonpathogenic A. rhizogenes strain K84 on crown gall of rose and tomato were almost identical, and the inhibitory effect of VAR03-1 on grapevine was superior to that of K84. Moreover, VAR03-1 greatly controlled crown gall of grapevine due to tumorigenic A. vitis in the field. VAR03-1 established populations averaging 106 colony forming units (CFU)/g of root in the rhizosphere of grapevine and persisted on roots for 2 years. VAR03-1 was bacteriocinogenic, producing a halo of inhibition against those three species of Agrobacterium. This is the first report that a nonpathogenic strain, VAR03-1, can effectively control crown gall caused by tumorigenic A. vitis, A. rhizogenes, and A. tumefaciens.

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