Identification of quantitative trait loci and associated candidate genes for low-temperature tolerance in cold-hardy winter wheat.
Low-temperature (LT) tolerance is an important economic trait in winter wheat (Triticum aestivum L.) that determines the plants' ability to cope with below freezing temperatures. Essential elements of the LT tolerance mechanism are associated with the winter growth habit controlled by the vernalization loci (Vrn-1) on the group 5 chromosomes. To identify genomic regions, which in addition to vrn-1 determine the level of LT tolerance in hexaploid wheat, two doubled haploid (DH) mapping populations were produced using parents with winter growth habit (vrn-A1, vrn-B1, and vrn-D1) but showing different LT tolerance levels. A total of 107 DH lines were analyzed by genetic mapping to produce a consensus map of 2,873 cM. The LT tolerance levels for the Norstar (LT(50)=-20.7 degrees C) x Winter Manitou (LT(50)=-14.3 degrees C) mapping population ranged from -12.0 to -22.0 degrees C. Single marker analysis and interval mapping of phenotyped lines revealed a major quantitative trait locus (QTL) on chromosome 5A and a weaker QTL on chromosome 1D. The 5A QTL located 46 cM proximal to the vrn-A1 locus explained 40% of the LT tolerance variance. Two C-repeat Binding Factor (CBF) genes expressed during cold acclimation in Norstar were located at the peak of the 5A QTL.
Båga
Monica
M
Department of Plant Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, S7N 5A8, Canada.
Chodaparambil
Sanjay V
SV
Limin
Allen E
AE
Pecar
Marin
M
Fowler
D Brian
DB
Chibbar
Ravindra N
RN
D003080:Cold Temperature; D005819:Genetic Markers; D026161:MADS Domain Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D040641:Quantitative Trait Loci / Q000235:genetics*; D014908:Triticum / Q000737:chemistry / Q000235:genetics* / Q000502:physiology
D005819:Genetic Markers; D026161:MADS Domain Proteins; D010940:Plant Proteins