Endophytic Bacteria as Biocontrol Agents of Tomato Bacterial Wilt Disease

Abstract

Ralstonia solanacearum is a tomato pathogen causing wilt disease which can lose crop production up to 100%. This problem also has economical impact to Indonesia, though controlling this pathogen has been done before. Biological control using endophytic bacteria is one of alternative control methods to support agriculture sustainability. The objective of these experiments are isolating endophytic bacteria taken from healthy tomato stems and root as well as investigating patogens as biocontrol agents of tomato bacterial wilt disease. Among 10 isolates found, only Ps1 and Ps8 can inhibit R. solanacearum based on antagonistic test in vitro using seed coat method and 4-7 mm inhibition zone forming. In vivo test was applied in green house in 30 days old of tomatoes using endophytic bacteria by the root soak technique. The result shows Ps1 and Ps8 within 15-16 days incubation period have suppressed 8.07%-9.19% pathogen attack.

Selection and Formulation of Endophytic Bacteria as Plant Resistance Elicitor against Wilt Disease of Tomato

“…The suspension was made by adding 10 mL sterile water into pure isolate and homogenized. The seed was sowed on soil media, after 30 days old seedlings was transferred to polybag that have been filled soil media for a further experiment (Purnawati et al 2014).…”

“…Suspension with 24 hours old was taken 400 mL and then inoculated into the bacterial carrier mixture. The awaited treatment for 20 minutes then stored at 25 ± 2°C for 3-4 days until dry to obtain powder form (Purnawati et al 2014).…”

“…The treatment was incubated for 24 hours at 28°C. The observed variable was the clear zone around the seed at 24, 48, 72 hours (Purnawati et al 2014).…”

Molecular identification of <i>Fusarium</i> spp. from wilt-infected tomato and brinjal plants in selected regions of Sri Lanka and endophytic bacteria as a potential option for disease management

“…Isolates of the endophytic bacteria were characterized following conventional methods including colony appearances and biochemical properties. To differentiate Gram positive and negative bacteria, a loop full of each isolated bacterium was placed on a glass slide with a drop of 3% (v/v) KOH solution, stirred for 10 seconds and was observed for the formation of slime threads (Purnawati et al, 2014).…”

“…Moreover, the survival of its resting structures, i.e., chlamydospores in the soil for many years without a host, and limits the suppressive effect of crop rotation (Vethavalli and Sudha, 2012). Biological control using endophytic bacteria is one of the alternative control methods used in integrated plant diseases management, supporting agricultural sustainability (Purnawati et al, 2014). Endophytic bacteria live in various tissues and organs of healthy plants.…”