Co-PIs: Ming-Cheng Luo and Patrick E. McGuire (University of California-Davis), Muhammad Javed Iqbal (North Dakota State University), Makhdoom Hussain (Wheat Research Institute, Faisalabad, Pakistan), and Shahzada Munawar Mehdi (Soil Salinity Research Institute, Pakistan)
Collaborators: Edward J. DePeters, Emanuel Epstein, and William D. Rains (University of California-Davis), and Dennis Falaschi (Panoche Water District, Firebaugh, CA)
Salinity limits agriculture in many semiarid areas of the world. In Pakistan, the partner country of this project, two million hectares (ha) of the total 21 million ha of land are salinized and are either unsuitable or only marginally suitable for agriculture. Salinized land can be reclaimed with appropriate agronomic practices and engineering interventions and/or by growing salt-tolerant crops. Unfortunately, improvement of salinity tolerance of major crops has been disappointingly slow because of their inherent salt sensitivity. This project takes a reverse strategy by improving agronomic attributes of plants naturally able to tolerate salinity. Perennial tall wheatgrasses and their close relatives have exceptional salt tolerance and some produce a large quantity of forage in saline environments. A unique asset of tall wheatgrasses is that they can be hybridized with wheat, producing plant materials that are often exceptionally salt tolerant. While the chromosomes of wheat and wheatgrasses do not recombine naturally, recombination between chromosomes of these species can be induced through the use of genetic stocks containing mutations in the homoeologous pairing gene Ph1. The goal of this project is to evaluate the possibility of developing novel salt-tolerant germplasm with recombined genomes derived from hybridization between wheatgrass and wheat using the Su1-Ph1 (Suppressor of Ph1) system. Amphiploids developed from these crosses will be characterized by cytogenetic and genetic approaches as well as for mineral content, nutritional quality, and agronomic traits. Field evaluations will be conducted in California and in Pakistan. For genetic analysis, wheatgrass genomes will be sequenced and genetic markers specific for wheatgrass germplasm will be developed.
This project will have an impact reaching far beyond developing technology and materials for agriculture on saline soils in Pakistan. Basic knowledge about genetic manipulation of recombination between wheat and alien chromosomes with the objective of producing novel plant forms with recombined genomes will be generated and disseminated. This knowledge can be deployed in hybridization of wheat with species other than wheatgrasses in order to produce novel cereals with improved tolerance of drought, heat, cold, or waterlogging or with novel attributes, such as perennial growth habit. The salt-tolerant materials developed in this project will facilitate future discovery of genes controlling high salt tolerance in wheatgrasses and their deployment in biotechnology of wheat and other crops in addition to the immediate use of this germplasm in breeding programs in Pakistan and other countries with saline soils. Wheatgrass genome sequences and the wheatgrass genetic markers will be deposited at NCBI (www.ncbi.nlm.nih.gov)and on the project website with links in GrainGenes (http://wheat.pw.usda.gov/GG2/index.shtml) and Gramene (www.gramene.org), respectively. Genetic materials will be offered for long term storage and distribution to the National Plant Germplasm System and the Wheat Genetic and Genomic Resources Center, Kansas State University.
