Confirming QTL for seed yield from exotic soybean germplasm

Hendrix, Charles C.

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https://hdl.handle.net/2142/18357 Copy

Description

Title

Confirming QTL for seed yield from exotic soybean germplasm

Author(s)

Hendrix, Charles C.

Issue Date

2011-01-14T22:47:25Z

Director of Research (if dissertation) or Advisor (if thesis)

Nelson, Randall L.

Committee Member(s)

• Bullock, Donald G.
• Diers, Brian W.

Department of Study

Crop Sciences

Discipline

Crop Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Soybean
• Quantitative trait loci (QTL)
• Yield
• Confirmation
• Exotic Germplasm
• Plant Introductions

Abstract

The genetic improvement of soybean (Glycine max (L.)) cultivars in North America (N.A.) has, for the most part, been accomplished by intermating elite cultivars. This breeding strategy, combined with the limited N.A. genetic base, has resulted in a very narrow gene pool. Plant introductions (PI) have been used to expand the N.A. genetic base with limited success when conventional breeding methods have been used. Quantitative trait loci (QTL) mapping has been used to identify genetic regions within PIs that could contribute both genetic diversity and improved seed yield potential in the N.A. gene pool. Of the putative QTL for seed yield that have been identified, only a small percentage have been tested in confirmation trials and even fewer have been confirmed. The objective of this study is to confirm putative QTL for seed yield derived from Exotic germplasm that were identified in previous QTL mapping studies. One BC1F9 confirmation population was developed from the cross Kenwood x LG94-1713 to test the QTL associated with SSR loci Satt405 (linkage group (LG), J chromosome (chr) 16) and two BC1F11 populations were developed to test Satt477 (LG O, chr 10) and Satt557 (LG C2, chr 6). Four F8 confirmation populations were developed from the cross of BSR 101 x LG82-8379 to test the QTL linked to Satt142 (LG H, chr 12), Satt225 (LG A1, chr 5), Satt363 (LG C2, chr 6), and Satt544 (LG K, chr 9) and two F9 populations were developed to test Satt168 (LG B2, chr 14) and Satt358 (LG O, chr 10). Unfortunately, no putative QTL for seed yield were confirmed in any of the populations developed from the BSR 101 x LG82-8379 mapping population. A QTL for plant height, maturity, and seed yield associated with Satt557 was confirmed in two populations developed from Kenwood x LG94-1713 with the beneficial allele coming from the LG94-1713 parent but these results were confounded by the tight linkage of Satt557 to the E1 locus. In both populations maturity was delayed by slightly more than 5 days in the lines homozygous for the LG94-1713 allele. However, there were differences between the two populations for both plant height and seed yield. The allele from LG94-1713 in one population increased plant height by 4.6 cm and seed yield by 0.32 Mg ha-1 more than in the second population. We hypothesize that a crossover occurred in one of the populations that separated the putative QTL from Satt557 but not from E1 and this QTL is responsible for the increase in seed yield and plant height. Several polymorphic single nucleotide polymorphism (SNP) markers have been identified between the two parents, which are on either side of Satt557. The lines in both populations are being tested with these markers to determine if and where the crossover occurred. If our assumption is correct, this confirmed QTL for seed yield may add additional genetic diversity and higher seed yield potential to the N.A. gene pool.

Graduation Semester

2010-12

Permalink

http://hdl.handle.net/2142/18357

Copyright and License Information

Copyright 2010 Charles C. Hendrix

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