II. Effect of Pathotype of Pathogens and the Use of Infected Straw on the Development of Kresek

한국에 있어서의 'Kresek'에 관한 연구 II. 균형 및 이병짚 시용이 Kresek 미치는 영향

  • Choi Y. C. (Dept. of plant Pathology, IAS., O.R.D.) ;
  • Cho Y. S. (College of Agriculture, S.N.U.) ;
  • Chung B. J. (Dept. of plant Pathology, IAS., O.R.D.)
  • Published : 1978.03.01


The study has been carried to confirm the pathotypes of Kresek inducing isolates of X. oryzae, and its reaction to the test plants when they were inoculated by the use of various methods. Induction of Kresek symptom by 23 isolates which randomly samplified from 123 Kresek areas through the country also were examined. The specificity of Pathotypes I, II, V in causing Kresek and the potenciality of infected rice straw is a first inoculum for Kresek epidemics in nature were tested. Fifteen out of 23 isolates from kresek area belonged to pathotype group I, while the rest of 8 isolates 5 howed group II reaction, and the most of isolates were originated from infected rice plant of Milyang #23. All of five pathotype groups were abled to produce 'Kresek' symptom although they showed some differences in each group of pathotype. The varieties Milyang #21, 22 and 23 were attacked by all isolates of group I, II and V while the Gogyoku group varieties including Yushin produced kresek symptom only by pathotype group II. Infected and dried straw maintained the pathogens during the winter period, and these straw acted as a first inoculum of Kresek disease when the straw were cutted and used as a manure just before transplanting of rice seedling.