Developing frost tolerance in wheat

Project summary

Researchers are developing a reliable and reproducible frost screening method for all frost-prone areas of Australia to aid current and future research into frost-tolerant lines of wheat.

The ultimate goals are to breed frost-tolerant wheat varieties and help growers make better management decisions with regards to crop choice, variety choice and sowing dates.

Outcomes

• The traditional view is that there is very little variation in frost tolerance between Australian wheat varieties. The current project has demonstrated that significant differences do exist and the magnitude of the variation is of economic relevance.
• Within mainstream wheat varieties, Wyalkatchem is particularly sensitive to frost-induced sterility at the flowering stage while Yitpi exhibits greater tolerance.
• Genetic analysis has shown the differences in frost tolerance are influenced by similar chromosomal regions to those previously identified in barley, suggesting a common tolerance mechanism in both species.
• Synthetic wheat derivatives have shown encouraging levels of frost tolerance in trials conducted over a number of years. Populations have been developed from these lines and are being used to determine if these exotic wheats offer different genetic mechanisms for improving frost tolerance in future varieties.
• Phenotypic and genotypic information is being made available to all pre-breeding and breeding organisations on equal terms, consistent with the Australian Winter Cereals Pre-Breeding Alliance terms, to develop varieties with significantly improved frost tolerance.

Background

Frost damage causes significant economic losses to Australian cereal farmers in affected areas. Losses average more than $33M a year in South Australia and Victoria alone.

International research and breeding efforts have resulted in significant improvements in frost tolerance at the vegetative stages of crop development, which is an important production constraint in many northern hemisphere environments. However, the importance of frost tolerance at flowering is almost unique to Australia.

Frost events that occur close to flowering can cause floret sterility and significantly reduce yield. Subsequent frosts during grain filling can result in downgrading of grain quality.

The unreliability of screening methods and/or the lack of apparent genetic variation for frost tolerance have seen this important trait remain intractable to plant breeding. Recent advances in field-based screening methods, experimental design and statistical analysis provide an opportunity to benchmark the level of frost tolerance in Australian varieties and exotic germplasm. Investigations into the genetic basis for any significant differences can then be made.

Related projects

CSP00131 – Finding the balance between frost tolerance and flowering time in wheat 

UA00063 – Breeding for frost tolerance in barley

UA00100 – Nationally coordinated frost trials – southern region