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A Rapid and Efficient Method for Assessing Pathogenicity of Ustilago maydis on Maize and Teosinte Lines
Published on: January 3, 2014
High segregation distortion in maize B73 x teosinte crosses
1Shanghai Key Laboratory of Bio-Energy Crop, School of Life Sciences, Shanghai University, Shanghai, PR China.
Genetics and Molecular Research : GMR
|April 27, 2012
Summary
Genetic maps of maize and teosinte were created using simple sequence repeat markers. Recombination distances varied significantly, with higher segregation distortion in the cross between maize and Zea mays ssp diploperennis.
Area of Science:
- Plant genetics
- Genomics
- Maize breeding
Background:
- Cultivated maize (Zea mays) has a complex genetic history involving wild relatives like teosinte.
- Understanding the genetic diversity and relationships between maize and teosinte is crucial for crop improvement.
Purpose of the Study:
- To construct genetic linkage maps for two teosinte species crossed with a maize inbred line.
- To compare the genetic map lengths and identify regions of segregation distortion between the two crosses.
Main Methods:
- Construction of two genetic linkage maps using simple sequence repeat (SSR) markers.
- Population 1: 81 F(2) individuals from a cross between maize inbred line B73 and Zea mays ssp parviglumis.
- Population 2: 63 backcross individuals from a cross between maize inbred line B73 and Zea mays ssp diploperennis.
Main Results:
- 172 SSR markers mapped to 10 chromosomes in the B73 x Z. mays ssp parviglumis F(2) population (2210.8 cM).
- 258 SSR markers mapped to 10 chromosomes in the B73 x Z. mays ssp diploperennis backcross population (1357.7 cM).
- Extensive segregation distortion regions were observed in both populations, with higher distortion in the B73 x Z. mays ssp diploperennis cross.
Conclusions:
- The genetic map length of Z. mays ssp diploperennis is shorter than that of Z. mays ssp parviglumis.
- Significant segregation distortion indicates potential genetic incompatibilities or selection pressures during hybridization.
- Recombination distances are highly variable in crosses between cultivated maize and wild teosinte species.
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