Figure 3. Representative adventitious roots from sweetpotato ‘Beauregard’ plants subjected to different virus treatments and grown with or without nitrogen.

+ N  =  nitrogen provided as KNO₃, - N = no nitrogen provided. V0  =  plants derived from non-inoculated, virus-tested plant stock; V1  =  plants derived from V0 plant stock graft inoculated with the potyvirus complex (SPFMV, SPVG, SPVC, and SPV2); V2  =  plants derived from plant stock infected with SPCSV. SR = localized swelling indicative of successful storage root initiation. Scale bar  = 5 cm.