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United States Department of Agriculture

Agricultural Research Service

Research Project: DEVELOPMENT OF IMPROVED PEANUT GERMPLASM AND RESISTANCE TO DISEASE AND NEMATODE PESTS

Location: Crop Genetics and Breeding Research

Title: Acceleration of peanut breeding programs by molecular marker assisted selection

Authors
item Chu, Y -
item Ozias-Akins, P -
item Holbrook, C

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 15, 2013
Publication Date: July 1, 2013
Citation: Chu, Y., Ozias-Akins, P., Holbrook Jr, C.C. 2013. Acceleration of peanut breeding programs by molecular marker assisted selection. Proc. 6th International Conference on Advances in Arachis through Genomics and Biotechnology. p. 39.

Interpretive Summary: not required

Technical Abstract: Peanut breeding has played a significant role in yield increases and disease control. Conventional breeding focuses on field selection and phenotypic analysis and it typically takes 12-15 years before a new cultivar can be released. Molecular markers developed from sequencing data can be of great use to shorten the peanut breeding cycle. As an example, molecular markers for two qualitatively inherited traits, high oleic acid and nematode resistance, were developed and applied in large scale breeding programs to integrate both traits into elite peanut cultivars. The high oleic trait is governed by two recessive genes ahFAD2A and ahFAD2B encoding for a delta-12-desaturase. Inactivation of both genes is necessary for expression of the high oleic trait. Peanut cultivars grown in the southeastern US largely possess the mutant allele of ahFAD2A; therefore, our breeding program has been targeted at selecting for the ahFAD2B mutation. Nematode resistance was introgressed from A. cardenasii, a wild diploid species related to peanut. A large introgressed chromosomal region on LG9A was found to confer the resistance. Molecular markers tightly linked to this introgressed region were used in our breeding program. High accuracy and reliability of the molecular markers were confirmed by phenotypic data. By using a backcross strategy, a nematode resistant cultivar Tifguard was converted to ‘high oleic Tifguard’ in only 26 months. The detection platform for both markers was upgraded from CAPS and SSR markers to high resolution melting curve and KASPar assays which greatly improves the throughput, accuracy and efficiency of marker assisted selection. As the peanut genomic sequencing data becomes available, more genetic traits of peanut can be mapped and converted to user friendly markers for peanut cultivar development.

Last Modified: 4/20/2014
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