[Mapping the trait controlled by two duplicate genes in the DH or RIL population].

While there is linkage between molecular marker and trait controlled by two duplicate genes in the DH or RIL population, the recombination rate (RR) between molecular marker and one gene controlling the above trait may be estimated by the maximum likelihood method. Moreover, the standard deviation of RR was also obtained in this paper. Finally, the results from Monte Carlo simulation with 3000 replications showed that the unbiasedness of RR for various sample size and RR was good, and the variation of the estimated value of RR decreased with the increase of sample size or RR.