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United States Department of Agriculture

Agricultural Research Service

Title: QTL MAPPING USING NEAR-ISOGENIC LINES.

Authors
item Holland, Jim
item Hostert, Brian - NORTH CAROLINA STATE UNIV
item Stuber, Charles - USDA, RETIRED
item Ledeaux, John - MONSANTO

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: November 30, 2001
Publication Date: N/A

Technical Abstract: Quantitative trait loci (QTL) analysis provides a valuable tool to plant breeders by identifying regions of the plant genome that influence agronomically important traits. The use of near-isogenic lines (NILs) may have some advantages over recombinant inbred lines (RILs) by homogenizing the genetic background and minimizing confounding effects of background QTLs. In this study we used maize NILs to map QTLs in the inbred Tx303 that influence agronomic responses in a cross between two widely used inbreds, B73 and Mo17. In an effort to develop superior inbred lines, 90 NILs were created by crossing B73 and Tx303 and then backcrossing to the recurrent parent B73. Marker-assisted selection was performed in the creation of the NILs by selecting for Tx303 at one or two target loci and B73 at all other loci. Nineteen restriction fragment length polymorphisms (RFLP) were initially used to develop the NILs. Each BC3F2:3 NIL was crossed to Mo17 and agronomic traits were measured in four different environments over two years. For each of the measured traits, QTLs were detected in one or more of the introgressed Tx303 segments. In order to estimate the proportion of Tx303 germplasm remaining in the B73 background, 110 simple sequence repeat (SSR) and RFLP markers were used to genotype each of the BC3F2:3 NILs at 20-30 cM intervals. On average, approximately 6% of NIL genetic backgrounds are derived from

Last Modified: 9/1/2014
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