Project Number: 5440-21000-025-00
Project Type: Appropriated

Start Date: May 31, 2003
End Date: Mar 27, 2008

Objective:
1. To determine whether increased expression of HMW (high-molecular weight) glutenin genes in wheat endosperm can result in improved baking quality of hard winter wheat, and if such approaches can confer greater environmental stability of quality, and to determine if there are any negative effects of transgenic expression on agronomic properties. 2. To develop and characterize adapted waxy (amylose-free) and partial waxy wheats, and to exploit the waxy gene system to produce novel wheat starches. 3. To identify and characterize new sources of resistance to preharvest sprouting, and sources of low or nil grain polyphenol oxidase. 4. To coordinate the Hard Winter Wheat Improvement Program and supervise the Hard Winter Wheat Regional Performance Nursery Program.

Approach:
Winter wheats with enhanced dough strength will be developed by transgenes conditioning over-expression of native HMW glutenin subunits. Transgenic wheats will be compared to non-transgenic sister lines and adapted check cultivars. At both tetraploid (durum wheat) and hexaploid (common wheat) levels, genetic populations consisting of sister lines carrying all possible combinations of waxy protein alleles will be developed. These lines will be used to establish the role of amylose content in durum and bread wheat quality, and to develop new types of starches for commercial applications. Traditional breeding and genetic approaches will be used to develop white winter wheats with enhanced resistance to pre-harvest sprouting and reduced levels of grain polyphenol oxidase (PPO). Matings between lines with low will be used to generate, via complementation, common wheat lines lacking PPO. Modified diallel matings will be used to generate populations of white wheats combining genes for resistance to pre-harvest sprouting from various sources. Inheritance studies will be conducted with both PPO and pre-harvest sprouting populations.