A SSR Linkage Map of Maize×Teosinte F2 Population and Analysis of Segregation Distortion

In this study, a linkage genetic map was constructed using a F2 population derived from a cross between a elite maize inbred, B73, and its progenitor, Teosinte (Z. mays ssp. mexicana), through 205 simple sequence repeat (SSR) markers and one morphological marker. By Mapmaker 3.0, polymorphic markers were clustered into 10 groups, covering 10 chromosomes of maizexteosinte, with a total length of 2 002.4 cM and an average interval of 9.7 cM. Genotyping errors were detected using R/QTL (LOD=2.0) in 109 markers referring to 176 individuals, distributed across all 10 chromosomes with a ratio 1.2%. Projected error loci were re-run and 304 out of the 460 were confirmed as errors and replaced. A new linkage map was constructed, in which markers maintained the same order but the total map length decreased to 1 947.8 cM, with an average interval of 9.4 cM between markers. In total, 25.2% (P<0.05) markers were identified to have segregation distortion, in which 34.6% deviated towards the pollination parent (B73), 30.8% deviated towards Teosinte, 32.7% deviated towards heterozygote and 1.9% deviated towards both parents. This map was also compared with published maizexteosinte and maize IBM map.