Characterization of a set of chromosome single-segment substitution lines derived from two sequenced elite maize inbred lines

Abstract

Chromosome single-segment substitution lines (SSSLs) are powerful tools for detecting and precisely mapping quantitative trait loci (QTLs) and evaluating the action of genes as single Mendelian factors. In this study, 108 SSSLs, which included 46 uniquely substituted segments, were developed from an advanced backcross proce¬dure with the marker-assisted selection of 146 simple sequence repeat (SSR) markers using the elite maize inbred line Zheng58 as the recipient and Chang7-2 as the donor. Each SSSL contained a single substituted chromosome segment that was derived from donor strain Chang7-2 in the genetic background of the recipient Zheng58 strain. The 46 substituted segments were unevenly distributed on ten maize chromosomes, and the substituted segment length ranged from 2.7 centimorgan (cM) to 283.5 cM with an average of 66.0 cM. The total length of the 46 substi¬tution segments was 3,035.2 cM, which covered 2,142.6 cM (31.47%) of the entire maize genome. To evaluate the potential application of these SSSLs for QTL detection, 44 SSSLs were used for the phenotypic characterization of plant height in three field trials. Twenty-nine QTLs of plant height were identified, and the percentages of additive effects varied from -8.45% to 12.86%. The results demonstrated that these SSSLs possesses large genetic varia¬tions and are excellent tools for genetically dissecting complex traits over several environments.