Oct 28, 2020
DIY testing: Impatiens necrotic spot virus (INSV)
We talked a bit about INSV in last newsletter and the importance of the virus in produce industry.
Impatiens necrotic spot virus, also known as INSV is a tospovirus closely related to Tomato spotted wilt virus. Infected plants usually have leaves with brown to dark brown necrotic areas. Sometimes the symptoms may be confused with “chemical burn”. As necrosis progresses the leaf browns or die out. Plants infected in early stage may become stunted and die or become unmarketable.
![201027-03 201027-03](/images/default-source/agricultural-ipm/veg-ipm-update-images/201027-03.png?sfvrsn=23d8d97c_2&MaxWidth=600&MaxHeight=&ScaleUp=true&Quality=High&Method=ResizeFitToAreaArguments&Signature=52C2A7616575EDA647DFF767D41477FF96F13186)
As visual diagnosis of the virus is confusing and could even be misleading at times, it is very important to confirm a symptomatology via clinical diagnosis.
The good news is there are tools available for quick and easy diagnosis of INSV. You can order the immunostrips from Agdia (https://orders.agdia.com/agdia-immunostrip-for-insv-isk-20501)
The immunostrips cost anywhere from $5-20 depending on how much you buy. They perform better when they stay refrigerated until just before use.
![201027-04 201027-04](/images/default-source/agricultural-ipm/veg-ipm-update-images/201027-04.png?sfvrsn=58f7ffcb_2&MaxWidth=400&MaxHeight=&ScaleUp=true&Quality=High&Method=ResizeFitToAreaArguments&Signature=739E5B80C4C700A2DB7F69B8C63DAAB9E3A3106D)
Immunostrips are quick and easy tool to use. The kit comes with a buffer bag and immunostrip.
1. You need very little tissue for diagnosis. The rule of thumb is plant tissue the size of your thumbnail.
2. Then you put the tissue in the buffer bag and gently grind it with something blunt (you can even use a sharpie/marker as shown in picture below)
![201027-05 201027-05](/images/default-source/agricultural-ipm/veg-ipm-update-images/201027-05.png?sfvrsn=5e694298_2&MaxWidth=400&MaxHeight=&ScaleUp=true&Quality=High&Method=ResizeFitToAreaArguments&Signature=16CF91D164F8C8019D1F655164AF1C68AD63AADC)
3. Let it sit for a minute and Insert the inmmunostrip on the side of the mesh bag in the tissue blended solution. You will see the plant sap going up in the immunostrip.
4. Results: 2 bands means positive and one band means negative!
One band means that the positive control worked which means the system worked. Sometimes you see no bands at all. This means the system did not work and you have to repeat the test.
To contact Bindu Poudel go to:
bpoudel@email.arizona.edu