Study in vitro of the impact of endophytic bacteria isolated from Centella asiatica on the disease incidence caused by the hemibiotrophic fungus Colletotrichum higginsianum.
Thirty-one endophytic bacteria isolated from healthy leaves of Centella asiatica were screened in vitro for their ability to reduce the growth rate and disease incidence of Colletotrichum higginsianum, a causal agent of anthracnose. Isolates of Cohnella sp., Paenibacillus sp. and Pantoea sp. significantly stimulated the growth rate of C. higginsianum MUCL 44942, while isolates of Achromobacter sp., Acinetobacter sp., Microbacterium sp., Klebsiella sp. and Pseudomonas putida had no influence on this plant pathogen. By contrast, Bacillus                 subtilis BCA31 and Pseudomonas fluorescens BCA08 caused a marked inhibition of C. higginsianum MUCL 44942 growth by 46 and 82 %, respectively. Cell-free culture filtrates of B.                 subtilis BCA31 and P. fluorescens BCA08 were found to contain antifungal compounds against C. higginsianum MUCL 44942. Inoculation assays on in vitro-cultured plants of C. asiatica showed that foliar application of B.                 subtilis BCA31, three days before inoculation with C. higginsianum MUCL 44942, significantly reduced incidence and severity of the disease. The role of endophytic bacteria in maintaining the apparent inactivity of C. higginsianum MUCL 44942 in C. asiatica grown in the wild is discussed.
Earth and Life Institute, Mycology, Université catholique de Louvain, place Croix du Sud 2 bte L7.05.06, 1348, Louvain, Belgium. erickfrancisco_rakouth@yahoo.fr
Erick Francisco
EF
Rakotoniriana
Mamy
M
Rafamantanana
Denis
D
Randriamampionona
Christian
C
Rabemanantsoa
Suzanne
S
Urveg-Ratsimamanga
Mondher
M
El Jaziri
Françoise
F
Munaut
Anne-Marie
AM
Corbisier
Joëlle
J
Quetin-Leclercq
Stéphane
S
Declerck
D001419:Bacteria / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D028041:Centella / Q000382:microbiology*; D020231:Colletotrichum / Q000254:growth & development / Q000472:pathogenicity*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D060026:Endophytes / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*; D056265:Microbial Interactions; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S