Studies on Tolerance and Rate-reducing Bacterial Pustule of Soybean Cultivars/Lines

Abstract

                Bacterial pustule caused by Xanthomonas campestris pv. Glycines (Nakano) Dye, was investigated from all soybean growing regions in Thailand and sixteen isolates of causal organism were collected. Morphological, physiological and biochemical characteristics of the causal organism were also studied, after that they were kept in paraffin oil for further studies.

                  Approximately 68 soybean cultivars/lines of 35-45 days old were tested for their bacterial pustule reaction at Kampangsan and Suwan Farm locations. All plots were inoculated 2 times. Yield and seed size or seed weight were compared under heavily artificial infection. The result revealed that 20 soybean cultivars/lines were resistant, 9 susceptible while the rest 39 were intermediate. Yield and seed size of the susceptible cultivars/lines differ significantly from those of the resistant ones. Difference in bacterial pustule infection between resistant and susceptible cultivars/lines was 53.79% The average seed yield reduction in the susceptible cultivars/lines was 37.04% and 4.35% was attributed to seed size reduction, while that of resistant ones was 30.32% and 7.92% respectively. This study would be further conducted in the next 2 years to reach the ultimate goal of the project.