Identification of the causal agent of red fruit (Pandanus conoideus Lamk.) leaf blight disease and its control using bacterial rhizosphere

Abstract

Red Fruit (Pandanus conoideus Lamk.) is an endemic plant in Papua, which is used for food and as pharmaceutical substance. A leaf blight disease of red fruit is occurred in Manokwari District. The symptom begins with a small spot and gradually enlarges into brown blight with dark brown at the center and surrounded by a yellow “halo”. The causal agent of the disease was not yet identified. This study was conducted to identify the pathogen of leaf blight based on morphology and molecular characters, to observe the abundance of rhizosphere bacteria and its ability as biocontrol agent. Based on Koch’s Postulates, morphological characterization, PCR and sequencing of 28S rDNA, the causal agent of leaf blight is identified as Fusarium sp. The fungal pathogen shows different characters from that of other Fusarium isolated from watermelon, melon, tomato, banana and jackfruit. Some heat tolerant bacteria isolates, chitinolytic bacteria isolates and a fluorescence bacterium originated from the rhizosphere of red fruit show ability to inhibit the growth of the pathogen.