Table 3.

Number of triple resistant gene heterozygotes identified and estimation of recurrent parent genome contribution

Generation	# of plants scored a	# of plants that are triple heterozygotes a, b	Estimated maximum % contribution of recurrent parent genome to selected backcross plant c	Expected % contribution of recurrent parent genome to selected backcross plant d
BC1F1	360	14	77.5	77.5
BC2F1	122	9	91.8	91.8
BC3F1	285	14	97	97

^aAt each backcross generation, genomic DNA was isolated from derivative lines and genotyping was performed using primers that are tightly linked to BB resistant genes as described in Materials and methods.

^bAt each backcross generation, fewer than expected triple heterozygotes were obtained. This is due to the fact that some of the

putative backcross progeny were obtained by inadvertent selfing of Jalmagna (the female parent in these backcrosses).

^cAt each backcross generation, genomic DNA was isolated from derivative lines that are triple heterozygotes for BB resistant gene linked markers. Microsatellite markers that are polymorphic between the parental lines were then used, as described in Materials and Methods, to identify the plant with maximum recurrent parent genome contribution.

^dAs per Mendelian ratios for independent gene action.