In this study, non-destructive technologies that can be applied to evaluate the integrity of valve materials, safety against internal pressure caused by corrosion, and the blocking function of large-diameter water valves during operation without requiring specimen collection or manpower entering the inside of the valve were tested to assess the reliability of the technologies and their suitability for field application. The results showed that the condition of the graphite structure inside the valve body can be evaluated directly through the optical microscope in the field without specimen collection for large-diameter water butterfly valves, and the depth of corrosion inside the valve body can be determined by array ultrasound and the tensile strength can be measured by instrumented indentation test. The reliability of each of these non-destructive techniques is high, and they can be widely used to evaluate the condition of steel or cast iron pipes that are significantly smaller in thickness than valves. Evaluation of blocking function of the valves with mixed gas showed that it can be detected even when a very low flow rate of mixed gas passes through the disk along with the water flow. Finally, as a result of evaluating the field applicability of non-destructive technologies for three old butterfly valves installed in the US industrial water pipeline, it was found that it is possible to check the material and determine the suitability of large-diameter water valves without taking samples, and to determine the corrosion state and mechanical strength. In addition, it was possible to evaluate safety through the measurement results, and it is judged that the evaluation of the blocking function using mixed gas will help strengthen preventive response in the event of an accident.
Broad bean wilt virus 2 (BBWV2) is a species in the genus Fabavirus and family Secoviridae, which is transmitted by aphids and has a wide host range. The BBWV2 genome is composed of two single-stranded, positive-sense RNAs, RNA-1 and RNA-2. The representative symptoms of BBWV2 are mosaic, mottle, vein clearing, wilt, and stunting on leaves, and these symptoms cause economic damage to various crops. In 2019, Perilla fructescens leaves with mosaic and yellowing symptoms were found in Geumsan, South Korea. Reverse-transcription polymerase chain reaction (RTPCR) was performed with specific primers for 10 reported viruses, including BBWV2, to identify the causal virus, and the results were positive for BBWV2. To characterize a BBWV2 isolate (BBWV2-GS-PF) from symptomatic P. fructescens, genetic analysis and pathogenicity tests were performed. The complete genomic sequences of RNA-1 and RNA-2 of BBWV2-GS-PF were phylogenetically distant to the previously reported BBWV2 isolates, with relatively low nucleotide sequence similarities of 76-80%. In the pathogenicity test, unlike most BBWV2 isolates with mild mosaic or mosaic symptoms in peppers, the BBWV2-GS-PF isolate showed typical ring spot symptoms. Considering these results, the BBWV2-GS-PF isolate from P. fructescens could be classified as a new strain of BBWV2.
토마토반점위조바이러스 (TSWV)는 고추, 토마토 등 경제적으로 중요한 작물에 심각한 피해를 주는 바이러스들 중 한 종이다. TSWV의 넓은 기주범위, 매개충인 총채벌레 방제의 어려움 및 TSWV의 효과적인 치료제가 없기 때문에, 저항성 품종을 사용하는 것이 TSWV를 예방하는 가장 효과적인 수단이 될 수 있다. 본 연구에서는 토마토에서 분리된 TSWV 분리주 (SW-TO2)의 유전학적·생물학적 특성을 구명하고, 최근에 국내에서 분리된 구기자, 머위, 당귀 TSWV 분리주와 비교하였다. 순수분리된 SW-TO2는 28 종의 지표식물 중 토마토를 포함한 17종에서 원형반점, 모자이크 증상 등 전신감염 증상을 보였다. SW-TO2의 유전자 계통분석 결과 국내에서 분리된 고추, 구기자 TSWV 분 리주와 98~99%의 상동성을 보이며 같은 그룹에 속하였다. TSWV 저항성 평가를 위한 생물검정법을 확립하고, 시판되고 있는 고추와 토마토 품종을 대상으로 4종의 TSWV 분리주에 대한 저항성 평가를 검정하였다. TSWV 저항성 평가는 첫째, 접종엽에 괴사반점 증상이 나타나거나 병징이 없는 경우, 둘째, 상엽에 병징이 없는 경우, 셋째, 상엽을 RT-PCR 진단한 결과 음성이 나왔을 경우 등 3가지 조건이 다 충족될 때 저항성으로 평가하였다.