Abstract
Nested association mapping (NAM) is a valuable innovation and multi-parental mapping population strategy in peanut genetics which increases the power to map quantitative trait loci and assists in extending the gene pool of elite peanut lines. In the peanut research community, two structured mapping populations were developed using a 2 × 8 (common by unique) factorial nested association mapping design, each with eight founders and a reference line. Here, we demonstrate its usefulness by assessing the phenotypic diversity of two assembled NAM populations (2 × 4). The common parents are Tifrunner and Florida-07 while the four unique parents are N08082oilct, C76-16, NC3033 and SPT06-06. We initially screened the phenotypic characteristics of the RILs including morphological and disease resistance traits. We found that leaf length and width, plant size, main stem height, and leaf spot resistance segregated within the assembled population and exhibited normal distributions. We also calculated the variance and heritability of each trait, and found that plant size had the lowest narrow sense heritability (0.06) while disease resistance had the highest (0.67) in the Tifrunner NAM population. In the Florida-07 population, main stem height had the lowest (0.27) and leaf width had the highest (0.73). Phenotyping of pod and kernel traits is underway along with further genotyping by sequencing. The NAM concept will promote the evaluation of the genetic diversity present in peanut gene pool.