Topics: Genetic map, linkage, recombination
You are working at International Rice Research Center (IRRI) in Philippines to map salt tolerance in rice.
After an extensive plant breeding analysis and different loci involved you have narrowed salt tolerance
at a locus which may exist between four recessive phenotypic markers i. e. m n o and p. While mapping
these markers on genetic map of rice you have crossed two true breeding rice strains. F1 from this cross
was used for a test cross with a plant which is homozygous for these four different recessive traits
designated by m, n, o and p. A total of 1000 plants from progeny of test cross are evaluated for each of
the four traits. As mentioned above the recessive traits are designated m, n, o, p while the
corresponding dominant traits are designated with a “+”. The phenotypes and number of each of the
possible phenotypic classes are as following.