Location: Crop Genetics and Breeding ResearchTitle: Phenotyping and genotyping parents of sixteen recombinant inbred peanut populations
|CHU, Y - University Of Georgia|
|Holbrook, Carl - Corley|
|ISLEIB, T - North Carolina State University|
|BUROW, M - Texas A&M University|
|CULBREATH, A - University Of Georgia|
|TILLMAN, B - University Of Florida|
|CHEN, J - University Of Georgia|
|CLEVENGER, J - University Of Georgia|
|OZIAS-AKINS, P - University Of Georgia|
Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2017
Publication Date: 1/15/2018
Citation: Chu, Y., Holbrook Jr, C.C., Isleib, T.G., Burow, M., Culbreath, A.K., Tillman, B., Chen, J., Clevenger, J., Ozias-Akins, P. 2018. Phenotyping and genotyping parents of sixteen recombinant inbred peanut populations. Peanut Science. 45:1-11.
Interpretive Summary: Marker-assisted breeding is a powerful tool for variety development. A set of genetic markers can be applied to a segregating breeding population to assist the selection of individuals possessing genomic regions controlling the expression of desirable traits. Defining the marker-trait associations for most important traits is challenging since these traits often are inherited quantitatively and can be influenced by the environment. Previously we developed 16 recombinant inbred line populations (RILs) consisting of 4870 lines. The first objective of the current study was to identify and quantify traits that are likely to segregate among these populations. To this end, 25 traits related to yield, pod maturity, seed germination, plant morphology, disease resistance and salt tolerance were quantified among the parental lines. Traits demonstrating significant differences among the population parents were identified. The second objective was to determine the genetic polymorphism among the population parents. Single nucleotide polymorphisms (SNPs) between population parents ranged from 1,000 to 4,000 on Version 1 and 2,000 to 9,000 on Version 2 arrays.
Technical Abstract: In peanut (Arachis hypogaea L.), most agonomically important traits such as yield, disease resistance, and pod kernel characteristics are quantitatively inherited. Phenotypic selection of these traits in peanut breeding programs can be augmented by marker-assisted selection. However, reliable associations between unambiguous genetic markers and phenotypic tratis have to be established by genetic mapping prior to early generation marker-assisted selection. Previously, a nexted association mapping (NAM) population of 16 recombinant inbred line populations (RILs) consisting of 4870 lines was established. In order to facilitate effective mapping of such a large genetic resource, the first objective of the current study was to phenoytpe the parental lines for yield, pod traits, field maturity, germination, plant morphology, salt tolerance and resistance to tomato spotted wilt virus (TSWV) and late leaf spot (LLS). For most measured traits, more than one parental combination demonstrated statistically significant variation which can be further quantified and mapped in the respective RIL populations. The second objective of this study was to genotype the parental lines using the Arachis Axiom SNP arrays to reveal the marker density of the mapping populations. The version 1 array identified 1,000 to 4,000 SNPs among the population parents and the number of SNPs doubled on the Version 2 array. Further phenotying and genotyping of the NAM populations will allow the construction of high density genetic maps.