Abstract
The most common factor affecting wheat production and grain quality in Australia is water deficit - "drought." Drought and heat are considered the top priority among 15 abiotic stresses affecting wheat production in Western Australia (WA). In the WA wheatbelt, water deficit intensifies from anthesis to about 4 weeks later and severe drought usually occurs from a month after anthesis to maturity. Thus, terminal drought is a major problem for wheat production in WA and drought tolerance in wheat is a priority for research. A major limitation in this field is the lack of efficient approaches of drought tolerance screening and availability of drought tolerant germ plasm.
Our study has found that stem water soluble carbohydrate (WSC) mobilization has great significance for converting biomass into the grain under terminal water-deficit. However, stem WSC level is not, on its own, a reliable criterion for drought tolerant. The genes involved in the mobilization of stem WSC, 1-FEHs have been studied and the gene expression data, as a potential drought tolerant marker, define their crucial role in contributing to water deficit tolerance. QTL recently discovered provide some evidence for the possible gene function of the contribution to the grain yield components. This and other markers of grain yield components may be useful for wheat breeding in the future.
Lack of drought tolerant germplasm significantly slows down drought tolerant breeding in wheat. Introducing new germplasm from China will give great benefit to the Australian wheat breeding program. Hopefully the combination of genes from such diverse environments will enhance the production of new drought tolerant wheat in conventional breeding.