title: Modeling of genetic gain for single traits from marker-assisted seedling selection in clonally propagated crops.
abstract: Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest. Traditionally, genetic potential is determined by phenotypic evaluation. With the availability of DNA tests for some agronomically important traits, breeders have the opportunity to include DNA information in their seedling selection operations-known as marker-assisted seedling selection. A major challenge in deploying marker-assisted seedling selection in clonally propagated crops is a lack of knowledge in genetic gain achievable from alternative strategies. Existing models based on additive effects considering seed-propagated crops are not directly relevant for seedling selection of clonally propagated crops, as clonal propagation captures all genetic effects, not just additive. This study modeled genetic gain from traditional and various marker-based seedling selection strategies on a single trait basis through analytical derivation and stochastic simulation, based on a generalized seedling selection scheme of clonally propagated crops. Various trait-test scenarios with a range of broad-sense heritability and proportion of genotypic variance explained by DNA markers were simulated for two populations with different segregation patterns. Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability. Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available.
authors.affiliation: Department of Horticulture, Washington State University , PO Box 646414, Pullman, WA 99164-6414, USA.
authors.forename: Sushan
authors.identifier: 0000-0003-2299-570X
authors.initials: S
authors.lastname: Ru
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, University of Queensland , St Lucia, Brisbane 4072, Australia.
authors.forename: Craig
authors.initials: C
authors.lastname: Hardner
authors.affiliation: School of Biological Sciences, Washington State University , Pullman, WA 99164-4236, USA.
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Carter
authors.affiliation: Department of Horticulture, Washington State University Tree Fruit Research and Extension Center , Wenatchee, WA 98801, USA.
authors.forename: Kate
authors.initials: K
authors.lastname: Evans
authors.affiliation: Department of Horticulture, Washington State University , PO Box 646414, Pullman, WA 99164-6414, USA.
authors.forename: Dorrie
authors.initials: D
authors.lastname: Main
authors.affiliation: Department of Horticulture, Washington State University , PO Box 646414, Pullman, WA 99164-6414, USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Peace