title: Quantitative trait loci controlling leaf appearance and curd initiation of cauliflower in relation to temperature.
abstract: QTL regions on chromosomes C06 and C09 are involved in temperature dependent time to curd induction in cauliflower. Temperature is the main environmental factor influencing curding time of cauliflower (Brassica oleracea var. botrytis). Temperatures above 20-22 °C inhibit development towards curding even in many summer cultivars. To identify quantitative trait loci (QTL) controlling curding time and its related traits in a wide range of different temperature regimes from 12 to 27 °C, a doubled haploid (DH) mapping population segregating for curding time was developed and days to curd initiation (DCI), leaf appearance rate (LAR), and final leaf number (FLN) were measured. The population was genotyped with 176 single nucleotide polymorphism (SNP) markers. Composite interval mapping (CIM) revealed repeatedly detected QTL for DCI on C06 and C09. The estimated additive effect increased at high temperatures. Significant QTL × environment interactions (Q × E) for FLN and DCI on C06 and C09 suggest that these hotspot regions have major influences on temperature mediated curd induction. 25 % of the DH lines did not induce curds at temperatures higher than 22 °C. Applying a binary model revealed a QTL with LOD >15 on C06. Nearly all lines carrying the allele of the reliable early maturing parental line (PL) on that locus induced curds at high temperatures while only half of the DH lines carrying the allele of the unreliable PL reached the generative phase during the experiment. Large variation in LAR was observed. QTL for LAR were detected repeatedly in several environments on C01, C04 and C06. Negative correlations between LAR and DCI and QTL co-localizations on C04 and C06 suggest that LAR has also effects on development towards curd induction.
authors.affiliation: Institute of Horticultural Production Systems, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany.
authors.forename: Yaser
authors.initials: Y
authors.lastname: Hasan
authors.affiliation: Syngenta Seeds BV, Westeinde 62, BK 1601, Enkhuizen, The Netherlands.
authors.forename: William
authors.initials: W
authors.lastname: Briggs
authors.affiliation: Department of Agronomy, University of Rostock, Justus-von-Liebig-Weg 6, 18059, Rostock, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Matschegewski
authors.affiliation: Julius Kuehn-Institute, Federal Research Center for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Erwin-Baur-Str. 27, 06484, Quedlinburg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Ordon
authors.affiliation: Institute of Horticultural Production Systems, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Stützel
authors.affiliation: Julius Kuehn-Institute, Federal Research Center for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Erwin-Baur-Str. 27, 06484, Quedlinburg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Zetzsche
authors.affiliation: Syngenta Seeds BV, Westeinde 62, BK 1601, Enkhuizen, The Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: Groen
authors.affiliation: Department of Agronomy, University of Rostock, Justus-von-Liebig-Weg 6, 18059, Rostock, Germany. ralf.uptmoor@uni-rostock.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Uptmoor
mesh_terms: D000483:Alleles; D001937:Brassica / Q000235:genetics* / Q000254:growth & development; D002874:Chromosome Mapping; D005838:Genotype; D006238:Haploidy; D008957:Models, Genetic; D010641:Phenotype; D018515:Plant Leaves / Q000254:growth & development*; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D013696:Temperature