([dagger]) Inoculation treatment includes non-inoculation (NONE) and inoculation with TEV, PVY, and TVMV.
By comparing the mean cured leaf yield and plant height of the non-transgenic control genotypes (Table 1) and referring to the results of Xu et al., 1997b, the relative disease severity of the three viruses could be estimated as PVY [is greater than] TEV [is greater than] TVMV. The TVMV CP transgenic lines did not have any significant performance advantage over the non-transgenic control genotypes following TVMV and TEV challenge.
There were low, mostly not significant, correlations between TEV, PVY, and TVMV infection scores; ELISA readings; and yield.
Correlation coefficients between yield and infection scores and ELISA values for transgenic lines infected with TEV, PVY, TVMV, and AMV.
Score Score 14 DPI 46 DPI TEV Yield -0.1620(*) -0.1565(*) PVY Yield -0.0184 -0.1391 TVMV Yield -- -0.1968(*) AMV Yield -0.3756(**) -0.4708(**) ELISA 46 DPI Plant height TEV -0.0948(*) 0.2081(**) PVY -0.1100 0.2896(**) TVMV -0.0268 0.0170 AMV -0.4510(**) 0.5588(**) (*) and (**) Correlation coefficients were significant at P = 0.05 and P = 0.01 levels, respectively.
Yields for the TVMV CP lines in the non-challenged, TEV challenged, and TVMV challenged treatments were highly correlated.
The NIa genes of TEV, TVMV, and PVY were cloned with primers as shown in Fig.
To determine the effectiveness of the TVMV, TEV, and PVY NIa genes for PDR, several (8-12) independent transgenic lines were examined for their susceptibility to infection by one of the three viruses used in this study.
As previously noted, tobacco plants that express the TVMV NIa gene (noted in this report as TVMV-NIa By21 lines) are resistant to TVMV infection (16).
In a manner analogous to the studies with the TVMV and TEV NIa genes, we evaluated whether a full length PVY-NIa gene could provide resistance to PVY in transgenic tobacco.
Eight TEV-TVMV NIa By21 (TET21) lines were evaluated for their responses to TEV or TVMV infection.
Nine TVMV-PVY NIa By21 (TVP21) lines were chosen and examined for their responses to TVMV and PVY.