Identification and validation of QTLs for 100-seed weight using chromosome segment substitution lines in soybean.

The 100-seed weight (100SW) is one of the most important traits that control soybean yield. To identify the quantitative trait loci (QTL) of 100SW, 120 BCF chromosome segment substitution lines (CSSLs) were cultivated over three years. The CSSLs were developed from a cross between the cultivated soybean variety 'Jackson' and the wild soybean accession 'JWS156-1', followed by continuous backcrossing using 'Jackson' variety as a recurrent parent. A total of nine QTLs (, , , , , , , , and ) were detected on eight chromosomes. Of these, (LOD = 6.78-12.31) was detected over the three successive years on chromosome 12 as a novel, stable, and major QTL. To validate the effect of , a residual heterozygous line (RHL), RHL564, which showed heterozygous at the region, was selected from the BCF population. Of the two homologous genotypes in the progenies produced by self-pollination of RHL564, a higher seed weight was observed in the 'Jackson' genotype plants than that in the 'JWS156-1' genotype plants. was delimited in an interval of approximately 1,348 kb between the BARCSOYSSR_12_1282 and BARCSOYSSR_12_1347 markers on chromosome 12.