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Chromosomal regions associated with segregation distortion in maize
H. Lu1, J. Romero-Severson, R. Bernardo
1Department of Agronomy, Purdue University, 1150 Lilly Hall of Life Sciences, West Lafayette, IN 47907-1150, USA.
Summary
Segregation distortion, a deviation from expected gene frequencies, occurs in 17% of maize markers. Specific chromosomal regions, or segregation distortion regions (SDRs), were identified and linked to gametophytic factors.
Area of Science:
- Genetics
- Plant Breeding
- Genomic Mapping
Background:
- Segregation distortion alters expected genotypic frequencies.
- Understanding its occurrence and genetic basis is crucial for accurate linkage mapping.
Purpose of the Study:
- Assess segregation distortion frequency in maize.
- Identify chromosomal regions associated with segregation distortion.
- Examine gametophytic factor effects on linkage mapping.
Main Methods:
- Constructed a simple sequence repeat (SSR) linkage map for a maize F(2)Syn3 population.
- Compared segregation distortion with three published linkage maps.
- Analyzed 1,820 codominant markers across four mapping populations.
Main Results:
- 17% of markers (301/1820) exhibited significant segregation distortion (P < 0.05).
- Distortion frequency varied by population (19-36%).
- Identified 18 chromosomal regions (SDRs) consistently showing distortion, potentially linked to gametophytic factors.
Conclusions:
- Segregation distortion is common in maize linkage mapping.
- Consistent SDRs suggest underlying genetic factors.
- Segregation distortion's impact on map distance is minimal with single gametophytic factors.