Evaluation of fertile lines derived from the hybridization of Glycine max and G. tomentella

Ma, Justin

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https://hdl.handle.net/2142/29663 Copy

Description

Title

Evaluation of fertile lines derived from the hybridization of Glycine max and G. tomentella

Author(s)

Ma, Justin

Issue Date

2012-02-06T20:09:43Z

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

Nelson, Randall L.

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)

• Glycine tomentella
• Phytophthora root rot
• Sudden death syndrome
• wide hybridization
• soybean germplasm

Abstract

Hybridization with wild relatives of crops has been an important tool for incorporating traits such as disease resistance into many crops, but has not been utilized in soybean (Glycine max), besides a few examples involving its ancestor, G. soja. G. tomentella (2n=78) is a wild, perennial relative in the tertiary gene pool of cultivated soybean G. max (2n=40). G. tomentella has been shown to have high levels of resistance to several diseases, including soybean rust and soybean cyst nematode. We successfully created hybrids of these two species and developed partially fertile amphidiploid plants with 2n=118 with the use of colchicine, hormone treatments, and tissue cultures. After two to five backcrosses with the cultivar Dwight, we obtained genetically stable lines with 2n=40 and 2n=42. Phenotypic evaluation of plant height, maturity, and seed protein and oil concentration, confirm introgression of G. tomentella genes. Genotypic data obtained using a custom single-nucleotide polymorphism (SNP) GoldenGate array also showed introgression of G. tomentella genes across most G. max chromosomes. From a screening of 543 2n=40 lines, we identified two alleles among 34 lines with resistance to Phytophthora sojae. In tests comparing our resistant lines with known sources of resistance to Phytophthora root rot, one allele performed similarly to the resistance gene, Rps1k. An allelism test confirmed that this allele is allelic or tightly linked to the Rps1 locus. Other G. max x G. tomentella lines, coming from a different BC2 progenitor, performed similarly to Rps1a. Using greenhouse evaluations of 84 lines, we also identified partial resistance to Fusarium virguliforme, the causal agent of sudden death syndrome. Our best lines performed nearly as well the publicly available commercial cultivars, Cordell and LS94-3207, though not as well as the best check, PI 567374. Both of these traits significantly improved the disease resistance of Dwight, which showed no Phytophthora root rot or sudden death syndrome resistance in our experiments. Our results demonstrate the successful introgression of G. tomentella genes into G. max.

Graduation Semester

2011-12

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http://hdl.handle.net/2142/29663

Copyright and License Information

Copyright 2011 Justin Ma

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