감자수염진딧물 (Macrosiphum euphorbiae)의 온도별 발육은 12.5~27.5°C까지 2.5°C 간격 (상대습도 65±5%, 광주기 16L : 8D), 7개 온도조건에서 1~2령, 3~4령의 2단계로 구분하여 조사하였다. 약충의 사망률은 7개 온도 중 6개 온도에서 10% 미만이었으나, 27.5°C에서 사망률은 53.0% 였다. 온도별 발육기간은 15.0°C에서 15.5일, 25.0°C에서는 6.7일로 고온으로 갈수록 발육기간은 짧아졌으나, 27.5°C 에서는 발육기간이 다시 길어져 9.7일이었다. 약충의 발육 영점온도는 2.6°C였고, 유효적산온도는 144.5일도였다. 약충의 발육을 5가지 비선형발육모형에 적용한 결과 Logan6 (r2=0.99) 모형이 발육에 적합하였고, 발육완료분포모형은 2-Weibull과 3-Weibull의 모형 적합성 (r2)이 각각 0.92 와 0.93으로 유사하였다. 성충 수명과 산자 수에서 성충 수명은 온도가 증가함에 따라 짧아지는 경향을 보였고, 산자 수는 20.0°C에서 64.4개로 가장 많은 산자를 생산하였다. 생명표분석에서 순증가율 (R0)은 20.0°C에서 63.2로 가장 컸고, 내적자연증가율 (rm)은 25.0°C에서 1.393로 가장 컸다. 배수증가기간 (Dt)은 25.0°C에서 2.091로 가장 짧았다. 기간자연증가율 (λ)은 25°C에서 가장 컸고 (1.393), 평균세 대기간 (T)은 25°C에서 9.929로 가장 짧았다.
PVY (Potyviridae: potyvirus) is one of the most important potato virus affecting seed potato production and also it is transmitted non-persistently via aphids. For healthy seed potato production, a virus detection system is highly important in addition to aphid monitoring and control. To achieve this detection method, it need to fast and easy to use. About two decades ago RT-PCR based PVY detection method was developed. However that was very time consuming and has low sensitivity. Here, we developed an advanced PVY detection method which a uses the boiling extraction of the viral RNA from aphid stylet and amplification by specific primers located in the viral capsid protein gene. Therefore, it could directly synthesize cDNA of PVY viral capsid gene from extracted RNA of PVY using one-step RT-PCR method in very short time compared to previous methods due to the omission of RNA extraction step. We confirmed this PVY detection method using the two aphid species (Macrosiphum euphorbiae and Aphis gossypii) that known as PVY vectors. The efficiency of this PVY detection method was 60% to 80% from two the aphid species. Hence, this method could be potentially applied to virus free seed potato production programs.
Fifty potato cultivars were screened for potato aphid, Macrosiphum euphorbiae Thomas infestation degree in the field. Aphid honey dew secretion and contents of foliar substances (glycoalkaloids, total nitrogen, Ca, K and Mg) of the cultivars were measured in the laboratory to analyze the correlation between infestation degrees and those factors. The number of aphids ranged from 4.1 to 31.4 per five leaves. The lower density (less than 5 aphids) was found on cvs. Jidose, Recent, and Sebago. The aphid secreted highest (40.3 droplets) and lowest (15.7 droplets) honeydew on cvs. Jopoong and Anco, respectively. Degree of infestation is positively correlated to glycoalkaloids and total nitrogen contents of the potato leaf.