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Peanut (Arachis hypogaea L.) is an important nutrient-rich food legume and valued for its good quality cooking oil. The fatty acid content is the major determinant of the quality of the edible oil. The oils containing higher monounsaturated fatty acid are preferred for improved shelf life and potential health benefits. Therefore, a high oleic/linoleic fatty acid ratio is the target trait in an advanced breeding program. The two mutant alleles, ahFAD2A (on linkage group a09) and ahFAD2B (on linkage group b09) control fatty acid composition for higher oleic/linoleic ratio in peanut. In the present study, marker-assisted backcrossing was employed for the introgression of two FAD2 mutant alleles from SunOleic95R into the chromosome of ICGV06100, a high oil content peanut breeding line. In the marker-assisted backcrossing-introgression lines, a 97% increase in oleic acid, and a 92% reduction in linoleic acid content was observed in comparison to the recurrent parent. Besides, the oleic/linoleic ratio was increased to 25 with respect to the recurrent parent, which was only 1.2. The most significant outcome was the stable expression of oil-content, oleic acid, linoleic acid, and palmitic acid in the marker-assisted backcrossing-introgression lines over the locations. No significant difference was observed between high oleic and normal oleic in peanuts for seedling traits except germination percentage. In addition, marker-assisted backcrossing-introgression lines exhibited higher yield and resistance to foliar fungal diseases, i.e., late leaf spot and rust., Competing Interests: All authors have contributed equally to this research work and have no competing interests exist.

Peanut is one of the most important oilseed crops grown worldwide. In this study, the mutant ahFAD2 alleles conferring high oleic (HO) content are introgressed into an elite Indian cultivar GPBD4 which is also resistant to the foliar fungal diseases like rust and late leaf spot (LLS). The allele-specific PCR (AS-PCR) and cleaved amplified polymorphic sequences (CAPS) assays were used for the marker-assisted backcross (MABC) approach and 64 HO introgression lines (ILs) were generated. These ILs were tested for the FA compositions under the glasshouse and field conditions. The oleic acid and linoleic acid contents in the ILs were recorded to be between 68.94–82.33% and 1.74–10.87%, respectively, under glasshouse and 67.04–81.71% and 2.00–15.66%, respectively, under field conditions. The increase in the oleic acid content of the ILs over its recurrent parent (RP) was recorded to the tune of 28.78–53.80% and 33.70–62.96% under glasshouse and field conditions, respectively, indicating the stable expression of ahFAD2B gene in two different environments. On the contrary, linoleic acid showed 56.47–93.03% and 40.02–92.34% reduction in the ILs over its RP under glasshouse and field conditions, respectively. These ILs with a healthy FA profile can meet not only the nutritional requirements of a health-conscious society but also the industrial demands for better shelf life of oil and its products. [ABSTRACT FROM AUTHOR]

Background The nutritional quality, flavor, and shelf-life of both peanut products and its seeds are dependent on relative quantity of various fatty acids (FAs) like saturated, mono unsaturated fatty acid (MUFA) and poly unsaturated fatty acid (PUFA) present in its oil. High oleic (HO) peanut oils are extremely valued due to its superior nutritional composition for human health and augmented thermo-oxidative stability for industrial purposes. Scope and approach From the research perspective, noteworthy progress has been made during last three decades for the development of peanut lines having HO trait in its oil. In this review, the research achievements, perspectives, and prospects of peanut genetic improvement for HO trait is thoroughly discussed. Key findings and conclusions The research has helped not only understanding the genetics of HO traits and its genotype (G) by environment (E) interaction but also produced an enormous number of HO line throughout the world. Although, as of now, most of the high O/L cultivars developed are the outcome of traditional breeding efforts. But, with the advent of novel molecular techniques like CAPS and AS-PCR assay for HO peanut breeding program, it is extremely easy to achieve the traits through marker assisted selection (MAS) rather than through either conventional or genetic engineering approaches. The availability of peanut genome sequence and identification of different ahFAD2 gene families is also expediting the research for the breeding of HO peanut genotypes. [ABSTRACT FROM AUTHOR]

High oleate peanuts have two marketable benefits, health benefits to consumers and extended shelf life of peanut products. Two mutant alleles present on linkage group a09 ( ahFAD2A ) and b09 ( ahFAD2B ) control composition of three major fatty acids, oleic, linoleic and palmitic acids which together determine peanut oil quality. In conventional breeding, selection for fatty acid composition is delayed to advanced generations. However by using DNA markers, breeders can reject large number of plants in early generations and therefore can optimize time and resources. Here, two approaches of molecular breeding namely marker-assisted backcrossing (MABC) and marker-assisted selection (MAS) were employed to transfer two FAD2 mutant alleles from SunOleic 95R into the genetic background of ICGV 06110, ICGV 06142 and ICGV 06420. In summary, 82 MABC and 387 MAS derived introgression lines (ILs) were developed using DNA markers with elevated oleic acid varying from 62 to 83%. Oleic acid increased by 0.5–1.1 folds, with concomitant reduction of linoleic acid by 0.4–1.0 folds and palmitic acid by 0.1–0.6 folds among ILs compared to recurrent parents. Finally, high oleate ILs, 27 with high oil (53–58%), and 28 ILs with low oil content (42–50%) were selected that may be released for cultivation upon further evaluation. [ABSTRACT FROM AUTHOR]