
Elucidation of Cause of Cotyledon Black-Decay of Soybean Sprout by Bean Bug, Riptortus clavatus
- Jung-Han Lee Ki-Soo Han Dong-Kil Kim Jin Ho Kang Hee Kyu Kim
- 한국작물학회
- 한국작물학회지
- 제53권 제3호
- 등재여부 : KCI등재
- 2008.09
- 303 - 307 (5 pages)
Cotyledon Black Decay (CBD) on soybean sprout mimics the black spot due to microbial infection. CBD, not visible or predictable at seedlot state, for some reason, shows up exclusively on cotyledon of soybean sprout during sprouting process. Such an incidence rate fluctuated from 0.8 to 19.5% over three years from 2004. We suspected some pod-infecting anthracnose fungi and/or pod-blight path-ogen, or pod-sucking bean bug, one of the major pests of soybean, might have involved, of which we ruled out fungal pathogen because it was preventable through heat treatment, a proven method for seedlot disinfestation. The healthy seeds artificially fed by bean bug for one to seven days were sprouted, and 6 to 41% of the soybean sprout revealed the CBD mimic to those occurred in soybean sprout from previous commercial seedlot screening experiments. This finding is the first report to confirm that bean bug damage to pod at R8 stage is directly responsible for the CBD, which did not concur with any other deleterious effects on sprouting such as reduction in hypocotyls elon-gation and rooting except unsightly sprout quality. How-ever, earlier feeding either at green pod or greenish yellow pod stage (R6 -early R7 stage) resulted in rather severe dama-ges, which strikingly reduced hypocotyls growth to about one forth to about two third, as well as the reduction in rates of seed germination.
MATERIALS AND METHODS
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ACKNOWLEDGEMENT
REFERENCES