ARS | Publication request: ADVANCED BACKCROSS QTL ANALYSIS OF A HARD WINTER WHEAT-SYNTHETIC WHEAT POPULATION.

Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 2005
Publication Date: February 4, 2006
Citation: Narasimhamoorthy, B., Gill, B.S., Fritz, A., Nelson, C., Brown Guedira, G.L. 2006. Advanced backcross qtl analysis of a hard winter wheat-synthetic wheat population.. Journal of Theoretical and Applied Genetics.

Interpretive Summary: Broadening the genetic base of common wheat by transferring potentially useful genes from ancestral species is an important goal of wheat geneticists. Wide-crossing have focused mostly on traits such as pest resistance that are under simple genetic control. Most wild progenitor accessions are agronomically inferior to modern wheat varieties and even when they carry superior alleles for yield and related traits, it is difficult to identify and transfer these genes by conventional methods. In this study, we used advanced backcross quantitative trait locus (AB-QTL) analysis to search for genes affecting yield and yield components in a backcross population developed from a cross between hard red winter wheat variety Karl 92 and the synthetic wheat line TA 4152-4. Data were collected for agronomic traits on 190 BC2F2:4 lines grown in two Kansas environments. Severity of infection with wheat soilborne mosaic virus was also evaluated at one location. Microsatellite DNA markers were evaluated on the population. There were ten genes identified that affected the traits evaluated. The favorable allele was contributed by cultivated parent Karl 92 for seven genes, including a major one for WSBMV resistance, and by the synthetic parent at three: for grain hardness, kernels per spike, and tiller number.

Technical Abstract: Advanced backcross quantitative trait locus (AB-QTL) analysis was used to identify QTLs for yield and yield components in a backcross population developed from a cross between hard red winter wheat (Triticum aestivum L.) variety Karl 92 and the synthetic wheat line TA 4152-4. Phenotypic data were collected for agronomic traits including heading date, plant height, kernels per spike, kernel weight, tiller number, biomass, harvest index, test weight, grain yield, protein content, and kernel hardness on 190 BC2F2:4 lines grown in three replications in two Kansas environments. Severity of wheat soilborne mosaic virus (WSBMV) reaction was evaluated at one location. The population was genotyped using 151 microsatellite markers. Of ten putative QTLs identified, seven were located on homoeologous group 2 and group 3 chromosomes. The favorable allele was contributed by cultivated parent Karl 92 at seven QTLs including a major one for WSBMV resistance, and by the synthetic parent at three: for grain hardness, kernels per spike, and tiller number.