5.4.S.1 
Of more importance formerly than now is tobacco 
mosaic virus. Most (over 90 percent) of the tobacco 
grown in Wisconsin now is resistant to this virus by 
reason of its hypersensitive reaction. The 
experimental tobacco to be field tested was derived 
from a variety resistant to tobacco mosaic virus and it 
retains this resistance. 
5AJ&3. Cucumber mosaic virus has infected a large proportion 
of the plants in certain fields. Symptoms are very 
similar to those of tobacco mosaic virus infection. 
There is no satisfactory resistance to the virus in the 
genus Nicotiana (26). The virus is transmitted by 
aphids from infected perennial plants or from species 
in which the virus is seed transmitted. 
5AJ&3 Other viruses occur in low incidence in Wisconsin 
tobacco. Havana 42 5 tobacco is considered to have 
resistance to tobacco veinmottling virus (26), but this 
virus has not been reported to occur in Wisconsin. 
5 A . 9 Alterations in "Weediness" (Persistence of Tobacco) 
In the unlikely event of undesirable effects accompanying 
cultivation of the genetically engineered tobacco, it may be 
relevant to consider whether this tobacco might persist without 
cultivation, although no member of the genus Nicotiana is known 
Environmental Assessment 
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