Backcrosses to L. esculentum (bookstack)

Long Description: The cultivated tomato L. esculentum makes large red fruits and carries the mi allele for susceptibility to nematode infection. The wild tomato L. peruvianum makes small green fruits and carries the Mi allele for resistance to nematodes. The L. esculentum x L. peruvianum hybrid was backcrossed to L. esculentum for many generations to produce a new tomato line that contains the Mi gene.

image modified from Peggy Lemaux http://ucbiotech.org/

Long Description: The L. esculentum genome is represented as a red bookstack, while the L. peruvianum genome is represented as a white bookstack. The F1 hybrid is represented as a bookstack with half red books and half white books. Breeders performed many generations of backcrossing to L. esculentum and selecting for progeny that contained the Mi gene. These plants can be represented as a bookstack that is over 99% red with only one small white region containing the Mi gene. Unfortunately this white region also contained dozens of undesirable genes from the L. peruvianum parent.

Slide Links: