Abstract

In order to study the causal agents of tomato rot in tunnels/greenhouse, the tomato fruits (Solanum lycopersicum L) showing symptoms of soft rot was collected and their juices were used for the identification of microbes. Microbial isolates were obtained from lesions following surface sterilization and rinsing with distilled water.  Bacteria cultures were prepared on nutrient agar while fungal cultures were prepared on PDA (Potato Dextrose Agar). The morphological characteristics of cultured bacteria revealed a negative gram, a white shiny colony with mucoid growth, and characteristics of Erwinia corotovora causing soft rot. Pathogenicity test on ripe tomatoes in an experiment designed as complete randomized design (CRD) with four replicates revealed water-soaked lesions that gradually expanded. Following f-test and separation of means using least significant difference at 5%, the three different strains of E. carotovora were identified based on the diameter of the infection lesions. Fungal strains were identified as Rhyzopus stolonifer based on colony morphology and pathogenicity test on ripe tomato. Colonies on potato dextrose agar at 25°C was white-cottony at first, the brownish-black sporangia with many hanging black spores grew later.  The Sporangia were globose or sub-globose. The two different strains of R. stolonifer were identified based on their infection lesion size.

Key words: Erwinia Carotovora, Rhizopus stolonifer, tomato (Solanum lycopersicum L), soft rot.