Fig. 2. PCR assay to detect the presence or absence of the N transgene in Mtx^R GH96-3700 BC₁F₁ individuals from the cosegregation analysis. Reactions for TMV^R plants were expected to amplify a 540-base pair (bp) N-gene fragment. Lanes 1 and 28, 100 bp ladder; Lanes 2 and 3, untransformed TMV^S check genotypes Petite Havana and NC152-dhfr; Lanes 4 through 27, 24 different BC₁F₁ individuals. Comparative results from the TMV test are provided at the top of the panel.