Annotation of Trait Loci on Integrated Genetic Maps of Arachis Species
Peanut or groundnut (Arachis hypogaea L.) is second, behind soybean, in the world’s legume oilseed market. In 2012, global production was 41.2metric tons from an area of 24.7million hectares (FAOSTAT, 2014). Yield of peanut under stressed environments is an ultimate goal of improvement for enhanced production as it is usually susceptible to a range of abiotic and biotic stresses, such as drought, tomato spotted wilt virus (TSWV), early leaf spot (ELS) and late leaf spot (LLS), nematodes, rust, and aflatoxin contamination (Guo et al., 2012a). However, cultivated peanut is an allotetraploid (2n=4x=40) with a large genome, which greatly complicates interpretation of genomic data compared with the diploid wild relatives (2n=2x=20) (Guo et al., 2013). It is difficult to transfer alleles from wild species to cultivated peanuts (Simpson, 1991). For the last ten years, extensive efforts in the area of peanut genomics have resulted in a large number of genetic and genomic resources such as mapping populations, expressed sequence tags (ESTs), a wide range of molecular markers, transcriptome and proteomics (Guo et al., 2013; Katam et al., 2014; Varshney et al., 2013). These genetic and genomic resources have been successfully used to construct genetic maps, to identify quantitative trait loci (QTLs) of traits of Author's personal copy 164 Peanuts Peanuts, First Edition, 2016, 163207 interest, and to conduct markerassisted selection and association mapping for peanut improvement (Pandey et al., 2014a).