Linkage and Association Mapping for Yield-Related Traits in Wild Soybean (Glycine soja Sieb. and Zucc.)

High yield is the major breeding objective in soybean [Glycine max (L.) Merr.], however narrow genetic base of cultivar soybeans is becoming a bottleneck for high-yield breeding. Wild soybean (G. soja) with richness of high-yield genes is an important resource for soybean improvement. To identify yield-enhancing quantitative trait locus (QTL) or gene from wild soybean, QTLs for yield-related traits, including pods per plant (EPP), seed weight per plant (SWP) and 100-seed weight (SW), were mapped in the F₂ population (316 plants) derived from a cross between wild soybean JPWS-5 and cultivar soybean line 06-17, and association analysis was conducted in the natural population (113 wild soybean accessions) on yield-related traits. The main results were as follows: (1) 27 QTLs for seed and pod traits were detected by CIM. 18 additive-dominant QTLs, 13 pairs of epistatic QTLs were detected by MCIM. 11 QTLs were stably detected in different generations and years. There were three QTLs: qEPP-H-1, qEPP-Lb-1 and qSWP-Lb-1, with positive effects from wild soybean. (2) 16 SSR marker-trait associations were detected with MLM model (Q+K), four for EPP, five for SWP and seven for SW. Five significantly associated loci be both detected in 2011 and 2012. (3) The same genetic region related pod and seed traits were detected in the LGs H (Sat_334) and L (Sct_010) by QTL analysis and association mapping. These results would provide a basis for excavating excellent genes, broadening cultivated soybean genetic basis and molecular marker assisted breeding of yield in soybean.

Corresponding author: E-mail: dyyu@njau.edu.cn.