Table 4.

Viral disease Index of transgenic plants

Symptoms	Disease ratings	Disease index (%)	Disease reaction
Absence of symptoms	0	0	Immune
Thickening of a few small veins or the presence of leaf enations on 10 or fewer leaves of plants	1	0.1–1	Highly resistant
Thickening of the small group of veins	2	1.1–5	Resistant
Thickening of veins, but no leaf curling	3	5.1–10	Moderately resistant
Severe vein thickening or leaf curling at the top of the third plant	4	10.1–15	Moderately susceptible
Severe vein thickening or leaf curling on half of the plant	5	15.1–20	Susceptible
Severe vein thickening, leaf curling, stunted growth of the plant and less fruit production	6	>20	Highly susceptible