Project Number: 6208-21000-017-18
Project Type: Trust

Start Date: Apr 01, 2012
End Date: Apr 30, 2013

Objective:
1. To develop valuable breeding resources with early season cold tolerance from advanced recombinant inbred populations of sorghum. 2. To continue analysis of male sterile A3 cold-tolerant Chinese lines for studies on maternal/heterotic effects; AIMs mutants in elite background; advancement of populations and conversion of germplasm resources for identification of favorable alleles and full utilization of germplasm. 3. To carry out screening for disease/pest reactions of advanced populations, select lines and analysis of seed quality to integrate resistances to biotic stress with cold tolerance traits. 4. To utilize genomic tools for understanding and deploying cold tolerance in sorghum.

Approach:
This project is a continuation of existing cooperative research on sorghum cold tolerance to start to deliver germplasm products and technologies to the sorghum industry. Primarily, it involves identification of R (restorer) or B (maintainer) fertility reaction of selected RIL lines from BTx623 x PI567946 population developed at USDA-ARS Cropping Systems Laboratory through crosses with A1 or A3 cytoplasmic male sterile lines. Furthermore, development of A1 lines from select B-RIL lines and production of hybrids with elite adapted US and company inbreds will be carried out. Continuation of multi-location testing for early season cold performance will be conducted in Texas, Kansas, Iowa, South Dakota, and Illinois for selected germplasm lines. This research will continue to gather information on heterosis and maternal effects on early season cold-tolerance response from F1 hybrids from crosses of A3 cold-tolerant Chinese lines with elite grain sorghum lines and sweet sorghum. Production of advanced population/germplasm resources for cold tolerance from USDA-ARS at Lubbock, TX, and Stillwater, OK, and partial conversion lines of cold-tolerant Ethiopian germplasm, and development of stable AIMs mutants (B lines) that can serve as novel sources of cold tolerance will be performed. Determination of disease reactions to major seedling pathogen(s) of recombinant inbred lines and select lines and information on seed quality parameters for parents, select RIL lines, and F1 hybrids and analysis of their association with cold tolerance will be gathered. This project will also initiate study of cold-tolerance QTL from available RIL populations using joint genome-wide association analysis and accomplish combined QTL analysis for cold tolerance and disease resistance. Generation of data on single nucleotide polymorphism markers through next generation sequencing will be continued for further understanding of cold tolerance at molecular level.