Breeding and selection strategies to combine and validate quantitative trait loci for water-use efficiency and heat tolerance in China (G7010.02.01)

China is the world’s largest producer of wheat and Chinese wheat production is of critical importance to global food security. Climate change and changing water use patterns are projected to reduce the amount of water available for irrigated wheat production. It is therefore vitally important that more water-use-efficient (WUE) farming systems and wheat cultivars are identified. Since certain physiological traits – and their QTLs – are associated with genetic gains under drought (eg, in Mexico and Australia), and as the measurement of these traits has been standardised in previous GCP projects and associated research, they can be applied in breeding programmes in China. However, before these QTLs can be accumulated in breeding materials, it is important that the capacity to accurately phenotype WUE and heat stress tolerance be established locally.

Over the past decade or so, a number of genetic mapping populations have been developed and assessed under water stress. A number of putative QTLs of variable significance have been identified in a range of different environments. The challenge for wheat breeders is to use this information in a coherent way to improve WUE and heat tolerance in wheat. For China, the projections are that climate change will increase both drought and heat stress. While routine crossing and selection has achieved small incremental gains in productivity, these are however insufficient in keeping pace with consumer demand. As such, a new breeding strategy that allows breeders to effectively combine QTLs to improve WUE and heat tolerance is urgently needed.

Objectives

The overall objective of this project is to develop wheat germplasm adapted to Chinese production environments with greatly enhanced water-use-efficiency. The establishment of effective phenotyping protocols and more efficient breeding schemes will be essential to achieving these outcomes. Specific objectives are:

1. Implementing standardised drought and heat phenotyping protocols to physiologically evaluate genetic populations and germplasm resources in China.
2. Using MARS and the outputs of previous QTL studies to improve water-use-efficiency and heat tolerance of wheat in China.

Project partners