Coutts B A, Jones R A C
Crop Protection Branch, Department of Agriculture and Food Western Australia, Locked Bag No. 4, Bentley Delivery Centre, Perth, WA 6983, Australia, and School of Plant Biology and Institute of Agriculture, Faculty of Science, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
Plant Dis. 2015 Mar;99(3):387-394. doi: 10.1094/PDIS-07-14-0674-RE.
In glasshouse experiments, two isolates of Potato virus Y 'O' strain (PVY) were transmitted from infected to healthy potato plants by direct contact when leaves were rubbed against each other, when cut surfaces of infected tubers were rubbed onto leaves, and to a limited extent, when blades contaminated with infective sap were used to cut healthy potato tubers. However, no tuber-to-tuber transmission occurred when blades were used to cut healthy tubers after cutting infected tubers. When leaf sap from potato plants infected with two PVY isolates was kept at room temperature, it was highly infective for 6 to 7 h and remained infectious for up to 28 h. Also, when sap from infected leaves with one isolate was applied to five surfaces (cotton, hessian, metal, rubber vehicle tire, and wood) and left to dry for up to 24 h before each surface was rubbed onto healthy tobacco plants, PVY remained infective for 24 h on tire and metal, 6 h on cotton and hessian, and 3 h on wood. The effectiveness of disinfectants at inactivating this isolate was evaluated by adding them to sap from infected leaves which was then rubbed onto healthy tobacco plants. None of the plants became infected when bleach (42 g/liter sodium hypochlorite, diluted 1:4) or Virkon-S (potassium peroxymonosulfate 50% wt/wt, diluted to 1%) was used. A trace of infection remained after using nonfat milk powder (20% wt/vol). PVY infection sources were studied in 2011-2012 in the main potato growing regions of southwest Australia. In tests on >17,000 potato leaf samples, PVY was detected at low levels in seed (4/155) and ware (6/51) crops. It was also detected in volunteer potatoes from a site with a previous history of PVY infection in a seed crop. None of the 15 weed species tested were PVY infected. Plants of Solanum nigrum were symptomlessly infected with PVY after sap inoculation, and no seed transmission was detected (>2,500 seeds). This study demonstrates PVY can be transmitted by contact and highlights the need to include removal of volunteer potatoes and other on-farm hygiene practices (decontaminating tools, machinery, clothing, etc.) in integrated disease management strategies for PVY in potato crops.
在温室试验中，两种马铃薯Y病毒“O”株系（PVY）分离物可通过以下方式从受感染的马铃薯植株传播到健康植株：当叶片相互摩擦时、当将受感染块茎的切面在叶片上摩擦时，以及在一定程度上，当用被感染汁液污染的刀片切割健康马铃薯块茎时。然而，在切割感染块茎后再用刀片切割健康块茎时，未发生块茎间传播。当将感染两种PVY分离物的马铃薯植株的叶汁置于室温下时，它在6至7小时内具有高传染性，并且在长达28小时内仍具传染性。此外，当将来自感染一种分离物的叶片的汁液涂抹在五个表面（棉花、粗麻布、金属、橡胶汽车轮胎和木材）上，并在将每个表面在健康烟草植株上摩擦之前晾干长达24小时时，PVY在轮胎和金属上24小时内仍具传染性，在棉花和粗麻布上6小时内具传染性，在木材上3小时内具传染性。通过将消毒剂添加到来自感染叶片的汁液中，然后将其在健康烟草植株上摩擦，来评估消毒剂使该分离物失活的有效性。使用漂白剂（42克/升次氯酸钠，稀释1:4）或卫可（过硫酸氢钾50%重量/重量，稀释至1%）时，没有植株被感染。使用脱脂奶粉（20%重量/体积）后仍有微量感染。2011 - 2012年在澳大利亚西南部主要马铃薯种植区研究了PVY的感染源。在对超过17000份马铃薯叶片样本的检测中，在种薯作物（4/155）和商品薯作物（6/51）中检测到低水平的PVY。在一个之前种薯作物有PVY感染史的地块的自生马铃薯中也检测到了PVY。所检测的15种杂草均未感染PVY。龙葵植株在汁液接种后无症状感染PVY，且未检测到种子传播（>2500粒种子）。本研究表明PVY可通过接触传播，并强调在马铃薯作物PVY的综合病害管理策略中，需要包括清除自生马铃薯以及其他农场卫生措施（对工具、机械、衣物等进行消毒）。
