|KANDEL, JINITA STHAPIT - Washington State University|
|HUANG, MENG - Washington State University|
|ZHANG, ZHIWU - Washington State University|
Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2018
Publication Date: 6/14/2018
Citation: Kandel, J., Huang, M., Zhang, Z., Skinner, D.Z., See, D.R. 2018. Genetic diversity of clinal freezing tolerance variation in winter wheat landraces. Agronomy. 8(6),95.
Interpretive Summary: New QTL were discovered in winter wheat landraces for freezing tolerance. Winter wheat landraces adapt rapidly to harsh environments and develop tolerance to more extreme climates. QTL were discovered on 4A and 6A that contribute to increased freezing tolerance from landraces isolated from geographical regions above 40 degrees lattitude.
Technical Abstract: Wheat (Triticum aestivum L.) is a major cereal crop grown across a wide range of environments, but its productivity areound the world is challenged by various plant diseases and harsh environmental conditions. Wheat landraces from diverse geographic regions are a potential source of unexploited genetic diversity that can be introduced into modern wheat-breeding programs in search of resistance to abiotic stresses like freezing tolerance. This genetic diversity study of 553 winter wheat landraces based on single nucleotide polymorphisms (SNPs) revealed separate clusters of landraces related to the latitude of origin. Linkage block analysis revealed genomic regions with specific alleles skewed towards landraces from higher latitudes suggesting that migration to higher latitudes resulted in fixing of specific alleles. Electrolyte leakage was used to measure tolerance of freezing to -14°C, -l6°C, and -l8°C of 192 landraces. The regression analysis showed a significant negative correlation between latitude and electrolyte leakage with an R2 value of 0.14, (P<0.0001), indicating greater freezing tolerance in landraces from higher latitudes. Genome-wide association studies identified genomic regions in chromosomes 4A and 6A associated with higher latitudes and freezing tolerance, respectively. Landraces with freezing tolerance may be useful in developing new germ plasm as novel sources of greater cold hardiness.