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United States Department of Agriculture

Agricultural Research Service

Research Project: GENETIC AND CULTURAL PRACTICE IMPROVEMENT FOR SUSTAINABLE COTTON PRODUCTION

Location: Coastal Plain Soil, Water and Plant Conservation Research

Title: Genetic Dissection of Yield and Its Component Traits Using High-Density Composite Map of Wheat Chromosome 3A: Bridging Gaps Between QTLs and Underlying Genes

Authors
item Rustgi, Sachin -
item Shafqat, Mustafa -
item Kumar, Neeraj -
item Baenziger, P. Stephen -
item Ali, M. Liakat -
item Dweikat, Ismail -
item Campbell, Benjamin
item Gill, Kulvinder -

Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 26, 2013
Publication Date: July 31, 2013
Citation: Rustgi, S., Shafqat, M.N., Kumar, N., Baenziger, P., Ali, M., Dweikat, I., Campbell, B.T., Gill, K.S. 2013. Genetic Dissection of Yield and Its Component Traits Using High-Density Composite Map of Wheat Chromosome 3A: Bridging Gaps Between QTLs and Underlying Genes. PLoS One. 8(7):1-12. http:\\www.plosone.org e70526.

Interpretive Summary: Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, efforts were made to increase the precision of previously identified yield component gene regions, and to map gene regions for biomass-related traits. Many of the previously identified gene containing regions for yield and its component traits were confirmed, but in much narrower intervals. Comparison of the genetic map with the integrated physical map allowed estimation of recombination frequency in the regions of interest and suggested that a portion of genes for grain yield reside in the high-recombination regions, thus should be amenable to map-based cloning. Comparisons with the rice genomic DNA sequence identified 11 candidate genes for yield and yield related traits of which chromosomal locations of two (CKX2 and GID2-like) were confirmed using wheat genetic stocks.

Technical Abstract: Earlier we identified wheat (Triticum aestivum L.) chromosome 3A as a major determinant of grain yield and its component traits. In the present study, a high-density genetic linkage map of 81 chromosome 3A-specific markers was developed to increase the precision of previously identified yield component QTLs, and to map QTLs for biomass-related traits. Many of the previously identified QTLs for yield and its component traits were confirmed, but in much narrower intervals. Four novel QTLs one each for shoot biomass (Xcfa2262-Xbcd366), total biomass (wPt2740-Xcfa2076), kernels/spike (KPS) (Xwmc664-Xbarc67), and Pseudocercosporella induced lodging (PsIL) were also detected. The major QTLs identified for grain yield (GY), KPS, grain volume weight (GVWT) and spikes per square meter (SPSM) respectively explained 23.24%, 24.16%, 20.52% and 20.16% of the phenotypic variation. Comparison of the genetic map with the integrated physical map allowed estimation of recombination frequency in the regions of interest and suggested that QTLs for grain yield detected in the marker intervals Xcdo549-Xbarc310 and Xpsp3047-Xbarc356 reside in the high-recombination regions, thus should be amenable to map-based cloning. On the other hand, QTLs for KPS and SPSM flanked by markers Xwmc664 and Xwmc489 are not suitable for map-based cloning as these mapped to the low-recombination region. Comparisons with the rice (Oryza sativa L.) genomic DNA sequence identified 11 candidate genes (CGs) for yield and yield related QTLs of which chromosomal locations of two (CKX2 and GID2-like) were confirmed using wheat aneuploids. This study provides necessary information to perform high-resolution mapping, and/or map-based or CG-based cloning of yield QTLs.

Last Modified: 4/20/2014