New Perspectives on the Epidemiology of Citrus Stubborn Disease in California Orchards

Fig. 6. Arrangement of Spiroplasma citri isolates based on principal component analysis using as input the differential characters obtained in random amplified polymorphism DNA reactions: (A) Analysis including historic S. citri isolates (black squares) and new isolates (open squares); (B) S. citri isolates from orchards (sites) 3 to 6. Majority of isolates from orchards 3 and 6 formed a tight cluster at principal coordinate 1 (3) and principal coordinate 2 (0). Reprinted with permission from A. F. S. Mello, et al. (9).



Image from Plant Health Progress article:
New Perspectives on the Epidemiology of Citrus Stubborn Disease in California Orchards