Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/20/2005
Publication Date: 12/21/2005
Citation: Marza, F., Bai, G., Carver, B. 2005. Qtls for yield and related traits in the wheat population, ning 7840 x clark. Journal of Theoretical and Applied Genetics. 112:688-698. Interpretive Summary: Grain yield and associated traits are important factors in wheat improvement. Genetic information regarding genes to control yield and its components would facilitate development of high yield cultivars using molecular marker-based selection. A population of recombinant inbred lines (RILs) was derived from a cross between a hard wheat, Ning7840, and a soft wheat, Clark. A total of 15 yield-related traits were evaluated in three locations in Oklahoma from 2001 to 2003. A genetic linkage map with 410 molecular markers was constructed. We identified 10, 16, 30, and 14 genes for yield, yield components, plant adaptation (shattering and lodging resistance, heading date, and plant height), and spike morphology traits, respectively. Results of this study provide a benchmark for future efforts on gene identification for yield traits.
Technical Abstract: Grain yield and associated agronomic traits are important factors in wheat (Triticum aestivum L.) improvement. Knowledge regarding the number, genomic location, and effect of quantitative trait loci (QTL) would facilitate marker-assisted selection and the development of cultivars with desirable characteristics. Our objectives were to identify QTLs directly and indirectly affecting grain yield expression in the southern Great Planes of the USA. A population of 132 F12 recombinant inbred lines (RILs) was derived by single-seed descent from a cross between the Chinese facultative wheat Ning7840 and the US soft red winter wheat Clark. Phenotypic data were collected for 15 yield and other agronomic traits in the RILs and parental lines from three locations in Oklahoma from 2001 to 2003. Twenty-nine linkage groups, consisting of 363 AFLP and 47 SSR markers, were identified. Using composite interval mapping (CIM) analysis, 10, 16, 30, and 14 QTLs were detected for yield, yield components, plant adaptation (shattering and lodging resistance, heading date, and plant height), and spike morphology traits, respectively. The QTL effects ranged from 7 to 23%. Marker alleles from Clark were associated with a positive effect for the majority of QTLs for yield and yield components, but gene dispersion was the rule rather than the exception for this RIL population. Often, QTLs were detected in proximal positions for different traits. Consistent, co-localized QTLs were identified in linkage groups 1AL, 1B, 4B, 5A, 6A, and 7A, and less consistent but unique QTLs were identified on 2BL, 2BS, 2DL, and 6B. Results of this study provide a benchmark for future efforts on QTL identification for yield traits.