Phenotypic and Biochemical Trait Evaluation of the USDA Core Peanut Germplasm Collection.

Phenotypic and Biochemical Trait Evaluation of the USDA Core Peanut Germplasm Collection

S.W. Dezern*, G.E. MacDonald, E. van Santen, M.J. Mulvaney, Agronomy Department, University of Florida, Gainesville, FL 32611-0300; C. Holbrook, USDA ARS, Tifton, GA 31793-5766; and N.L. Anglin, International Potato Center, Lima, Peru.

Peanut (Arachis hypogaea) is an economically important leguminous crop grown globally in the tropics and subtropics. Cultivated peanut originated from a single chromosome doubling event between Arachis duranensis and Arachis ipaensis, resulting in an allotetraploid (AABB) genome, where 2n=40. Because of this single ancestral ploidy change, cultivated peanut has a fairly narrow genetic base, which places emphasis on the maintenance and preservation of genetic diversity in order to have effective breeding programs. The USDA peanut core collection was developed by Dr. Corley Holbrook as an effort to represent the entire USDA peanut germplasm collection, which contains roughly 10,000 accessions, in a more manageable collection of 831 accessions. Additionally, a mini-core collection, made up of 112 accessions, was developed as a subset of the core collection for more manageable research purposes . This project aimed to characterize the core collection over a number of different phenotypic traits, including yield, grade, plant architecture, pod volume, protein content, and oil composition. Pod volume for a 20 peanut sample in the core collection ranged from 45cc to 365cc. Yield ranged from 298 kg/ha to 5622. kg/ha in the mini-core collection, and from 45 kg/ha to 5480 kg/ha in the core collection. Percent sound mature kernels ranged from 31.7% to 80.9% in the core collection. Weight per 100 seed ranged from 66.8 grams to 271.8 grams in the mini-core collection, and from 56.5 grams to 288 grams in the core collection. Additionally, an accession profile, including images of flowers, seed, and in-shell peanuts, was created for each of the core lines. The results from this project will be freely available on the USDA ARS GRIN database, providing researchers with robust data on the core collection to be used in breeding and genetics programs.