Thirty-four plus percent recombination or 34 map units is a much better estimate of the true recombination frequency
between sepia and ebony but is still less than the official map distance probably because of the underestimation of the recombination frequency
due to the inability to detect double crossovers, as well as other factors.
The discussion above of the effect of selecting progeny with high numbers of recombinants differs somewhat from the discussion given in Darvasi and Soller (1995), in that they decreased marker spacing with increases in recombination frequency
due to additional rounds of random mating.
The size difference for this genetic interval is primarily due to a difference in recombination frequency
between Xfcc1 and Xfcg10, which is 2.7 cM on the WK [F.sub.2] map compared to 1.7 cM on the LDN [F.sub.2] map.
In fact, for each population size, an optimal recombination frequency
between loci exists that maximizes R[infinity].
is the recombination frequency
estimated from RIL genotypes per se, and [n.sub.r] and [n.sub.n] are the number of recombinant and nonrecombinant genotypes, respectively, between two loci (Haldane and Waddington, 1931).
Except for the case where a small [N.sub.sl] (<50 genotypes) is combined with a reduced recombination frequency
between the target gene and flanking markers (2 and 4 cM), the number of generations for selecting two individuals ([N.sub.i] = 2) in each generation is almost equivalent to the results of selecting one individual ([N.sub.i] = 1), with a population half that size for most of the cases in Table 1.
of the rye arm in the translocation 7DS.4R[L.sup.mon] with wheat homoeologues was very low.
Using the proportion of 7:3, it was calculated that of the overall recombination frequency
of 18.1%, about 12.7% recombination was in the distal and 5.4% in the proximal wheat segments.
Twice the number of dominant markers will be informative in the [F.sub.2] so that the expected recombination frequency
between the closest marker in the [F.sub.2] and the QTL will be half that in the Bc.
Two [1RS.sub.40:9].1BL chromosomes were present among 144 progeny chromosomes screened for a 1.4% recombination frequency
of the segment of 1BS shared by 1B+40 and T-9.
The probability that an odd number of crossovers occurs (i.e., recombination occurs) in an interval is the recombination frequency
r related to the map distance by Haldane's (1919) mapping function:
Over multiple cycles of selection, feedback may occur between these influences that compound the differences between inbreeding methods: repulsion linkages may both decrease expressed genetic variance and lead to fixation of unfavorable alleles; loci that remain polymorphic may be linked or unlinked leading to shifts in the average recombination frequency
among polymorphic loci.