토양중 Pythium속 사상균의 취락조사시 희석평판을 위한 희석배수가 균수에 미치는 영향을 조사한 결과 다음과 같은 결과를 얻었다. 1. 희석배수 1:50은 1:100보다 기대했던 것 보다 Pythium속 취락수가 감소했으며 높은 희석배수에서도 뚜렷한 상관관계를 보이지 않음. 2. 토양시료를 이용한 희석배수실험에서도 유사한 결과를 보였으나 1:50의 회석반복실험결과는 상관관계가 관찰되었음. 그러나 토양을 풍건시켰을 경우 취락의 감소경향을 발견하였음. 3. 본 시험에 사용한 두개의 사탕수수포장에서 채취한 토양에서 Pythium번식체가 균일하게 존재하지 않는 것을 확인할 수 있었으며 희석배수 1:50일때 상관관계를 보인 것은 토양중 균사파편 혹은 분주과정에서 균사위조현상에 기인된 것으로 생각됨.
The number of colonies often decreased more than would be expected in a dilution from 1:50 to 1:100; however, a lack of agreement between the dilution series and the number of colonies obtained also occurred at higher dilutions. In the experiments with each soil subsample, there was sometimes poor agreement between the number of colonies obtained at the same dilution from the A and B subsamples. However, repeated 1:50 dilutions of soil suspensions of subsamples A and B yielded similar numbers of colonies. In the second experiment series conducted with a second composite soil sample, the number of colonies obtained from each soil subsample decreased following air drying. The results suggest that it was difficult to obtain a uniform distribution of Pythium propagules in the two sugarcane field soils tested. The high number of propagules detected at the 1:50 dilution could have been due to hyphal fragments or connected hyphal swellings that separated during the final mixing or during plating.
