Project Number: 3096-21000-020-000-D
Project Type: In-House Appropriated
Start Date: Mar 1, 2013
End Date: Feb 28, 2018
The long-term objective of this plan is to develop sorghum inbred lines that possess superior tolerance to abiotic stresses, and high biomass and grain yield potential. We will integrate natural variation, induced mutation, phenotype-based and marker-assisted selection to identify the desirable traits and introduce them into elite sorghum inbred lines. Specifically, during the next 5 years we will focus on the following objectives: Objective 1: Develop new screening tools and genetic resources to identify sorghum lines with high grain or biomass yield potential under drought and temperature stresses. Subobjective 1A: Evaluate the relationship between dhurrin concentrations and the staygreen trait. Subobjective 1B: Evaluate the diversity of the stay-green trait among sorghum germplasm collections. Subobjective 1C: Evaluate the efficacy of stay-green markers in F1 hybrids. Objective 2: Identify novel sources of genetic variation for cold temperature and drought tolerance in sorghum. Subobjective 2A: Develop high resolution genetic and QTL maps using new ARS mapping populations to discover robust and effective DNA markers conditioning early season cold tolerance, and validate marker-assisted selection using a subset of cold tolerant inbreds. Subobjective 2B: Identify markers or genes associated with high seed number and erect leaf traits. Objective 3: Develop improved grain sorghum and non-grain, energy sorghum breeding lines with high grain or biomass yield potential under high abiotic stress environments. Subobjective 3A: Develop and release novel ARS germplasm with enhanced abiotic stress traits such as stay-green, cold tolerance, high grain number, and erect leaf traits. Objective 4: Accelerate sorghum community trait analysis and trait development, via a new USDA public sorghum crop genome database system, by providing open access to sorghum genome sequence information, germplasm diversity information, trait mapping information, and phenotype information, with an initial emphasis on sugarcane aphid resistance. [NP301, C4, PS4A, C1, PS1A, C2, PS2A, C3, PS3A]
Superior traits that enhance sorghum grain and biomass yield and abiotic stress tolerance, identified previously from mutation population and natural germplasm collections, will be mapped using classical genetic analysis and the state-of- art Next-Generation Sequencing technology. Molecular markers will be developed for the rapid introgression of these traits into elite commercial lines. Lines with high yield potential and superior resilience to abiotic stresses will be developed through a systematic approach integrating physiology, marker-assisted selection, and conventional breeding. This project will provide much needed support for sorghum genomic and genetic research and germplasm improvement. Sorghum is an important feed, biofuel, and food crop in the United States. It is a superior heat and drought resistant crop, and thus its importance for U.S. agriculture is increasing given the impacts of global warming and water scarcity. However, production losses caused by increasing pressure from the sugarcane aphid pest have recently slowed the growth of sorghum production. Thus, increased support for sorghum genomic, genetic, and germplasm information generation and sharing is urgently needed to accelerate the rate of improvement in high-value target traits. To meet this critical need, a new USDA-ARS public sorghum genomics and genetics database will be developed to increase information management capacity, promote open access data and information sharing, and open access to data analysis tools; to facilitate the development and implementation of standardized methods for the collection, analysis, and utilization of new sorghum data; and to enable sorghum researchers and breeders to accelerate the development of superior performing cultivars for U.S. producers. The project will leverage strategic biology-enabled information at USDA-ARS databases and genomics projects at Ithaca and Cold Spring Harbor, NY; Beltsville, MD; and Ames, IA. It will include field-based phenotyping at Lubbock, TX, and translation into biology-enabled crop breeding. It will include the assessment of community needs, development of workshops and training material to support stakeholder engagement, and development of standards. Thus, sorghum is a model for addressing extremely urgent stakeholder needs in the field through the application of traditional marker assisted strategies and the application of new biology-enabled models for crop breeding.