おとり植物を用いた捕捉法と最確値法を組み合わせた土壌中のジャガイモモップトップウイルスの定量評価

抄録

The relative infestation level of Potato mop-top virus（PMTV）, causal agent for spraing of potato, in soil was successfully evaluated. Fifty grams of soil were suspended in 200 ml of nutrient solution and the portion was diluted by 10-fold with a nutrient solution followed by further dilution to prepare the dilution series of soil suspension up to 10^４-fold solution. Three-week-old tomato bait plants were cultured with their root submerged in those soil suspensions for three weeks, then the infestation of PMTV on the bait roots was evaluated by DAS-ELISA. The numbers of PMTV-positve containers from three consecutive dilution levels were scored, and the infestation level of PMTV in soil was estimated by employing the most probable number（MPN）method. Using this method revealed that the infestation level of the spraing-affected field in Tokachi subprefecture, Hokkaido, was higher than other non-affected fields investigated.