This work was carried out to confirm and/or evaluate the efficacy of three Pseudomonas spp. strains against fire blight (Erwinia amylovora), southern bacterial wilt of tomato (Ralstonia solanacearum), bacterial spot/canker of stone fruits (Xanthomonas arboricola pv. pruni) and grapevine crown gall (Agrobacterium vitis). In the laboratory, there was a trend towards a higher colonisation of apple and pear flowers when Na-alginate (0.5%) was added to suspensions of freeze-dried cells of wild-types and rifampicin-resistant mutants of IPV.-BO G19 (P. putida) and IPV.-BO 4027C (a non-fluorescent Pseudomonas sp.) strains; E. amylovora populations on apple flowers were significantly reduced by strain IPV.-BO 4027C. In a field experiment, performed on actively growing shoots of pear scions ‘Abbé Fétel’ during Spring-Summer 2005, different treatments were also tested, including copper compounds the resistance inducers prohexadione-Ca (Regalis) and acibenzolar-S-methyl (Bion), and Serenade and BS-F4 (both based on Bacillus subtilis) etc. The strain IPV.-BO G19 plus Na-alginate was the most effective in reducing shoot blight incidence by 65% six weeks after wound inoculation with E. amylovora. A virulent R. solanacearum bv. 2, race 3 strain was inhibited by both these antagonists in vitro. When the pathogen was inoculated 48 h after their application (approx. 108 cfu/ml) to the root apparatus of tomato plants grown in a climatic chamber, bacterial wilt progression rate was clearly reduced; in particular, the strain IPV.-BO G19 was able to delay symptom expression and to reduce disease incidence by 100% and 37%, 9 and 21 days after inoculation, respectively. Under glasshouse conditions, BS-F4, Bion and IPV.-BO G19 reduced relative incidence of grapevine crown gall by 58%, 54% and 48%, respectively. The IPV.-BO G19 strain was also effective against X. arboricola pv. pruni: when sprayed on plum fruitlets it reduced disease incidence by 90% eight days after experimental inoculation with the pathogen.
Biondi E., Bini F., Lancioni P., Anaclerio F., Brunelli A., Bazzi C. (2006). Biological control agents as tools against some emerging bacterial plant diseases in Italy: a concrete perspective?. BERLINO : Herausgegeben von der B.B. fur Land.
Biological control agents as tools against some emerging bacterial plant diseases in Italy: a concrete perspective?
BIONDI, ENRICO;BINI, FEDERICA;LANCIONI, PIETRO;BRUNELLI, AGOSTINO;BAZZI, CARLO
2006
Abstract
This work was carried out to confirm and/or evaluate the efficacy of three Pseudomonas spp. strains against fire blight (Erwinia amylovora), southern bacterial wilt of tomato (Ralstonia solanacearum), bacterial spot/canker of stone fruits (Xanthomonas arboricola pv. pruni) and grapevine crown gall (Agrobacterium vitis). In the laboratory, there was a trend towards a higher colonisation of apple and pear flowers when Na-alginate (0.5%) was added to suspensions of freeze-dried cells of wild-types and rifampicin-resistant mutants of IPV.-BO G19 (P. putida) and IPV.-BO 4027C (a non-fluorescent Pseudomonas sp.) strains; E. amylovora populations on apple flowers were significantly reduced by strain IPV.-BO 4027C. In a field experiment, performed on actively growing shoots of pear scions ‘Abbé Fétel’ during Spring-Summer 2005, different treatments were also tested, including copper compounds the resistance inducers prohexadione-Ca (Regalis) and acibenzolar-S-methyl (Bion), and Serenade and BS-F4 (both based on Bacillus subtilis) etc. The strain IPV.-BO G19 plus Na-alginate was the most effective in reducing shoot blight incidence by 65% six weeks after wound inoculation with E. amylovora. A virulent R. solanacearum bv. 2, race 3 strain was inhibited by both these antagonists in vitro. When the pathogen was inoculated 48 h after their application (approx. 108 cfu/ml) to the root apparatus of tomato plants grown in a climatic chamber, bacterial wilt progression rate was clearly reduced; in particular, the strain IPV.-BO G19 was able to delay symptom expression and to reduce disease incidence by 100% and 37%, 9 and 21 days after inoculation, respectively. Under glasshouse conditions, BS-F4, Bion and IPV.-BO G19 reduced relative incidence of grapevine crown gall by 58%, 54% and 48%, respectively. The IPV.-BO G19 strain was also effective against X. arboricola pv. pruni: when sprayed on plum fruitlets it reduced disease incidence by 90% eight days after experimental inoculation with the pathogen.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.