Development of Stem Rust Resistance in Wheat Adapted to Pakistan
Plant Science Research
2013 Annual Report
1a.Objectives (from AD-416):
To evaluate, identify, and develop sources of resistance to stem rust in wheat genotypes that are adapted to growing conditions in Pakistan.
1b.Approach (from AD-416):
North Carolina Agricultural Experiment Station will identify and obtain sources of stem rust resistance in cooperation with the USDA/ARS Plant Science Research Unit (PSRU), and other collaborating breeding programs. These sources of resistance will be used as parents in the breeding program to introgress stem rust resistance into advanced breeding lines of winter wheat. Top and/or backcrosses to adapted elite lines will be made to develop desirable segregating populations. When available molecular markers for known sources of stem rust resistance will be used to characterize parental lines and in marker assisted transfer and selection of resistance. Segregating populations developed from the introgressions will be inbred and advanced using traditional and/or marker assisted breeding methods when markers are available. Pure lines selected from advance breeding populations will be genotyped using available molecular markers and phenotypes for reaction to stem rust will be obtained in cooperative disease screening experiments conducted in field, greenhouse and/or growth chamber trials. Elite lines having stem rust resistance will be evaluated in regional and uniform yield nurseries, and superior lines will be released as cultivars. Data and germplasm will be shared between ARS, North Carolina State University, and other collaborating scientists.
This research relates directly to inhouse objective to identify sources of resistance to stem rust in Pakistan wheats and introgress new resistance into Pakistan-adapted wheat.
Significant progress was made to safeguard food security in Pakistan through cooperative research aimed at identifying high yielding wheat varieties having resistance to local and global rust diseases. The components of this research include: Precise determination of the spectrum of rust pathogens in Pakistan and which wheat varieties they are capable of attacking and damaging. Identification of the number and effectiveness of rust resistance genes in Pakistan wheat varieties and promising lines. Understanding the nature of spread of rust pathogens in Pakistan’s wheat growing Provinces. Transferring farming practices that can increase and stabilize grain yield. These components have been advanced by initiating the genetic characterization of the races of rust in Pakistan during the 2012-13 wheat growing season; by genetic determination of the rust resistance present in Pakistani wheat varieties and promising lines (including resistance to stem rust, ‘Ug99’); by understanding the need to remove older, rust-susceptible wheat varieties from production – so less rust is available to spread by wind; and by demonstration of improved planting, fertilization, and crop rotations to maximize grain yield. In addition, the training of Pakistani scientists in modern pathology and breeding methods helped to build research capacity moving forward.