Abstract:
This study was conducted at the Rubber
Research Institute, Dartonfield, Agalawatta, Sri Lanka
to identify alternative biological control agents to
manage the Circular Leaf Spot Disease in rubber
cultivation. The newly reported Circular Leaf Spot
Disease caused by the Colletotrichum spp and
Pestalotioides group which is distributed in Sri Lanka
and also other rubber growing countries in the world. In
Sri Lanka, the incidence of the disease is increasingly
destructive in rubber plantations. In this study, we
isolated endophytic bacteria to assess their antagonistic
activity against pathogens causing Circular Leaf Spot
Disease (Gunarathne & Fernando, 2017). The
endophytic bacteria were isolated from Rubber leaves
using 3 clones (RRIC 100,121 and RRISL 203) at bud
wood nursery. The isolated endophytic bacteria were
analyzed using cultural and microscopic characters.
Results revealed that 16 endophytic bacteria were
isolated and six strains (Ctr EB1, P44, EB3, Cfr EB4,
Cfr EB1, Cfr EB4 and P20 EB5) were identified as the
most potent antagonistic endophytic bacteria based on
their inhibition percentage. This study highlights the
high potential of the isolated highest inhibition
percentage endophytic bacteria to combat the circular
leaf spot pathogens in Hevea brasiliensis.
