Abstract Detail

Crops and Wild Relatives

Rojas-Gutierrez, Juan Diego [1], Lee, Gwonjin [1], Oakley, Christopher [2].

Genome-wide association analysis of freezing tolerance in soft red winter wheat.

Approximately 2/3 of the land surface on earth experiences freezing temperatures for part of the year. Freezing tolerance is therefore likely to be an important adaptation for both natural populations and for crop varieties like winter wheat (Triticum aestivum L). Winter wheat represents 80% of the total wheat production in the US and is grown as a winter annual with fall sown seeds developing into an overwintering vegetative stage. Understanding the genetic basis of freezing tolerance in winter wheat furthers our knowledge of abiotic stress tolerance in plants and may inform breeding programs aimed at fine tuning the level of freezing tolerance for a given region. Most previous studies of the genetic basis of freezing tolerance in wheat involve crosses between spring and winter wheat varieties, and thus cannot uncover variation in freezing tolerance segregating within winter wheat. We addressed the following questions, 1) Is there genetic variation in freezing tolerance within a winter wheat panel? 2) If so, what is the genetic basis? and 3) Are there correlations between freezing tolerance and other agronomically important traits? We used a panel of 267 soft red winter wheat accessionswith a genotypic dataset of 34K SNPs, from the Triticeae Coordinated Agricultural Project, that have been previously used in GWAS of yield and yield related traits. We quantified cold acclimated freezing tolerance for this panel as survival through three days of freezing period at -8°C. We found significant genetic variation in freezing tolerance within the panel. In GWAS, we Identified 17 SNPs significantly associated with freezing tolerance on 9 different chromosomes. These SNPs were all located within 1Kb of putative genes, some of which their functions have been previously reported to be involved in freezing tolerance. We found significant genetic correlations between freezing tolerance and seven previously reported agronomic traits, and all of these correlations were positive except for days to maturity. The strongest correlations with freezing tolerance were yield and biomass. In sum, we found that considerable genetic variation in freezing tolerance exists in this panel, and that this variation is positively correlated with yield and yield related traits. Thus, these lines can be useful in breeding programs seeking to optimize freezing tolerance for present and future climatic conditions.

1 - Purdue University, Botany and Plant Pathology, 915 W State St, West Lafayette, IN, 47907, USA
2 - Purdue University, Botany And Plant Pathology, 915 W State Street, West Lafayette, IN, 47907, United States

Keywords:
Adaptive plasticity
Cold acclimation
Freezing tolerance
GWAS
Winter wheat
Yield.

Presentation Type: Poster
Session: P1, Crops and Wild Relatives Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1CW002
Abstract ID:398
Candidate for Awards:None