Genetic map of the primocane‑fruiting and thornless traits of tetraploid blackberry

Publication Overview
TitleGenetic map of the primocane‑fruiting and thornless traits of tetraploid blackberry
AuthorsCastro P, Stafne ET, Clark JR, Lewers KS.
TypeJournal Article
Volume126
Year2013
Page(s)2521–2532
CitationCastro P, Stafne ET, Clark JR, Lewers KS. Genetic map of the primocane‑fruiting and thornless traits of tetraploid blackberry. Theor Appl Genet. 2013. 126: 2521–2532

Abstract

Blackberry primocane fruiting, fruiting on first-year canes, has the potential to expand blackberry production both seasonally and geographically. The incorporation of the primocane-fruiting trait into cultivars with desirable horticultural attributes is challenging due to its recessive nature and tetrasomic inheritance. Molecular marker-assisted selection has high potential to facilitate incorporation, because breeders already use morphological marker-assisted selection of seedlings without marginal cotyledonary hairs to identify progeny that will be thornless when mature. The development of a genetic linkage map with these two traits is the first step to utilizing molecular markers in breeding for thornless primocane-fruiting blackberry cultivars. A full-sib family segregating for thornlessness and primocane fruiting, from a cross between ‘APF-12’ and ‘Arapaho’, was used to construct the first genetic map of tetraploid blackberry. Segregation patterns of several dominant markers and the two phenotypic traits fit those expected uniquely with tetrasomic inheritance (e.g., 5:1, 11:1 and 35:1). Some loci showed significant double reduction frequencies, but genotypes that could have originated only from double reduction were not found. The map consists of seven linkage groups (LG) in each parent, consistent with the basic number of chromosomes (2n = 4x = 28). Naming of LG1-LG6 followed that of the recently revised system for raspberry using SSR markers in common between blackberry and raspberry, and LG7 was tentatively defined by default. The loci controlling primocane fruiting and thornlessness were not linked to each other; thornless/thorny, the S Locus, was mapped on LG4, and the primocane-/floricane-fruiting locus, named in this work the F Locus, on LG7.
Features
This publication contains information about 2 features:
Feature NameUniquenameType
presence of prickles, thorns, or spinesRubus thorny-Sheritable_phenotypic_marker
floricane fruitingRubus floricane fruiting-Aheritable_phenotypic_marker
Featuremaps
This publication contains information about 2 maps:
Map Name
Rubus-APF12xAra-F1-APF12
Rubus-APF12xAra-F1-Arapaho