Location: Crop Genetics and Breeding ResearchTitle: Marker assisted selection (MAS) for breeding high oleic Tifguard) Author
Submitted to: American Peanut Research and Education Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2009
Publication Date: 1/15/2010
Citation: Chu, Y., Ozias-Akins, P., Holbrook Jr, C.C. 2009. Marker assisted selection (MAS) for breeding high oleic Tifguard. Proceedings American Peanut Research and Education Society 41:61. Interpretive Summary: not required
Technical Abstract: Tifguard, a peanut cultivar released in 2007, has near immunity to root-knot nematode and high resistance to TSWV. However, its oil composition is within the normal O/L range. Pyramiding the disease resistant traits of ‘Tifguard’ and the high O/L trait using MAS is our current goal for breeding. We chose our previously published dominant resistance marker 909/197 and a dominant susceptibility marker discovered in a population of Nematam x GP NC-WS 14 for nematode resistance screening. For the high O/L trait, a spontaneous high O/L peanut mutant F435 was first discovered and its genetic mutations were identified as 1) a G448A transitional mutation in the ahFAD2A allele and 2) a nonsense frame-shift induced by an A442 insertion in the coding region of the ahFAD2B allele. Later, high oleic Georgia-02C and Georgia Hi-O/L induced by '-irradiation mutagenesis were released but their genetic mutations had not been determined. We designed a cleaved amplified polymorphic sequence (CAPS) marker targeting the site of the A442 insertion in ahFAD2B. Based on the CAPS marker and sequencing data from Georgia-02C and Georgia Hi-O/L, their genetic mutations for the high O/L trait are the same as that of the spontaneous mutant line F435. Two crosses C1804: Tifguard x GA02C and C1805: Tifguard x Florida 07 yielded 28 and 17 F1 seeds, respectively. We applied the molecular markers for both traits and found the success rate for F1 crossing to be 86%. We also tested 150 individuals harvested from the first backcross generation and found a range of genotypes combining these two traits. The best combinations have been selected for the second backcross generation. It is possible that with MAS, high O/L Tifguard shall be developed within three years.