Measuring tools to map distance
, angles, areas and proportions for surgical planning
The Kosambi mapfunction (Kosambi, 1944) was used to convert recombination frequency to genetic map distance
in centi Morgan (cM).
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.
Marker order and map distance
in the Satt220-Satt536 interval were accurately determined using 92 recombinants (two plants derived from both recombinant gametes, and the rest from one recombinant gamete and one parental gamete) identified from 1911 B[C.sub.7][F.sub.1:2] plants.
An error of over 11% for shapes that represent T-junctions in road maps constitutes a considerable overestimation of the relevant map distance
. Muller-Lyer road junctions or boundary configurations are probably less frequent than T-junctions in spatial layouts.
To examine the relationship between genetic diversification of populations and their geographic relationships, a measure of genetic differentiation can be regressed against map distance
The Kosambi mapping function (Kosambi, 1944) was used to convert recombination frequency to genetic map distance
The relationship between effective population size ([N.sub.e]), recombination rate and LD ([r.sup.2] ) without mutation is summarized in [r.sup.2] = 1/(4[N.sub.e] c + 1), where c is linkage map distance
in Morgans (Sved, 1971).
Using Table 1, students determine the approximate map distance
between their two linked genes.
Based on the resulted DNA sequence a pair of SCAR primers were designed and synthesized and then successfully tagged the high sugar trait of sorghum with a 3.25 cM of linkage map distance
. This may provide an alternative strategy for the selection of new sweet sorghum varieties and cloning of high sugar-related genes.
Mapped loci covered a total map distance
of approximately 1660 cM.
The map distance
and marker distribution for the linkage groups were generated from analysis of the 116 [F.sub.4]--derived progeny from NC113.