We are currently doing genetic mapping in several segregating maize populations. Maps for some of these crosses, B73/Mo17, B73/G35, K05/W65, and J40/V94, were previously reported in this Newsletter (Beavis and Grant, 1991). The sizes of these populations range from approximately 100 to 250. Maps were created using MAPMAKER (Lander, E et.al.,1987) and composite maps were created using the log likelihood statistic as described by Beavis and Grant (Theor. Appl. Genet., 1991).
These maps include newly added probes, the changes resulting from our efforts to correct discrepancies caused by previously undetected scoring errors, and the name changes described in our accompanying Newsletter article. Scoring errors were revealed and analyzed using data integrity procedures developed at Pioneer Hi-Bred. The left-most map of every chromosome is a composite created using probes that have segregation scores in two or more populations. No marker order discrepancies were detected between these populations. The maps to the right of this are based on probes with segregation scores in only one, though not necessarily the same, population. The endpoints of the map intervals for these markers indicate flanking markers from the composite map that were used in mapping these markers.
The probes used came from Ben Burr, B (bnl), University of Missouri (umc), Asgrow/UpJohn (asg), Pioneer Hi-Bred (php) and several other outside researchers. Probes with the designator "npi" are originally from Native Plants Incorporated, but are now owned and distributed by Pioneer Hi-Bred.
1) For each chromosome, the left map is a composite based on data from two or more populations per probe and the maps to the right of this are based on data from one population per probe.
2) The markers in italics to the right of the chromosomes are based on recent mapping data; there are no flanking markers shown as the map position is only approximately known.
3) Data was originally compiled and map drawn on 8/21/92, nomenclature edited 1/6/93.
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