Location: Soybean and Nitrogen Fixation Research2013 Annual Report
1a. Objectives (from AD-416):
Development of drought tolerant soybean varieties.
1b. Approach (from AD-416):
Interdisciplinary approach involving breeders, physiologists and molecular geneticists. We have identified 9 exotic drought tolerant exotics in the USDA soybean germplasm collection. Genes conferring drought tolerance will be transferred to adapted varieties using a combination extensive field breeding and DNA tagging of drought QTL. Physiological studies will determine how the various drought QTL interact with the environment and each other, to facilitate their deployment.
3. Progress Report:
This project is related to Objective 3 of this in-house project: to discover novel genes/alleles in soybean for ‘tolerance to drought and related stress’, determine their inheritance, determine genomic location, transfer to adapted germplasm, and release. The Drought Tolerance project seeks to unlock the rich store of drought tolerance genes that exist in the USDA’s preserve of soybean germplasm. This preserve was formed by scientists through decades of work, combing the globe to find exotic soybean. This reservoir of exotic diversity, although collected by scientists, was produced originally by over 3000 years of ‘on-farm breeding’ in Asia, in which farmers adapted the soybean to a range of climate conditions, including drought. Special genes for drought tolerance, bred into soybean long ago by these ancient farmers, are key to coping with the problem of drought in the USA today. The drought problem is so severe for our farmers in the USA because U.S. varieties do not presently contain these special drought genes from Asia. The central theme of our drought tolerance work is that we can ‘turn the tables’ on drought in the USA by putting the world’s genetic resources to work. To that end, the USB drought tolerance project coordinates the research activities of 8 scientists and 7 research institutions in the Midwest and South. All of this effort is aimed at transferring drought genes from exotic Asian material into adapted genetic materials which will protect agriculture from damaging droughts. Since activation of this project in 2011, this project has completed DNA tagging of 5 slow-wilting genes from soybean PI 416937 and DNA tagging of a gene conditioning limited leaf hydraulic conductance in PI 416937. A new champion USDA slow-wilting breeding line (N05-7432) was discovered to have superior N-fixation capabilities under drought stress as well. Over 30 southern environments, this advanced breeding continued to outyield check varieties. More than 5000 yield plots were grown in drought prone areas and will be evaluated to identify drought tolerant soybean types. In Minnesota, the slow-wilting trait was transferred to new maturity-group 0 high-yielding soybean types. These new breeding lines are being advanced to the next tier of regional testing (Uniform Regional Test 0) in 2013. These new lines inherit their slow-wilting trait from USDA-ARS breeding stock developed at Raleigh by the Soybean and Nitrogen Fixation Soybean Unit. In Nebraska, research team members developed high yielding lines by crossing slow-wilting southern parental stock from the USDA-ARS to a Nebraska-adapted variety. These l0 lines were tested under drought conditions in KS, MO, AR, and NE in 2012 and are being retested in 2013. In Arkansas, two new high-yielding lines were developed which have drought tolerant N2-fixation. Breeding lines R02-1325 and R05-5559 were confirmed as having drought-tolerant N fixation. These are higher yielding than the earlier releases with drought tolerant N fixation. Also in Arkansas, a quantitative trait locus was identified for drought-tolerant N-fixation. In Georgia, new slow-wilting types exhibited a 3 bushel per acre yield advantage over conventional soybean cultivars under drought stress in 2012. Additional confirming studies are underway in 2013. Because of the tremendous drought in the Midwest in 2012 and the many exciting advances in the project, the research team convened in Raleigh to brainstorm about future research. A consensus was reached that we need to speed up our technology transfer of research advances to the farmer. Concrete ideas were discussed for accomplishing this goal. The Team also met in March 2013 to refine and implement these ideas. These advances help industry collaborators to better use drought-tolerant traits and genetic materials in applied breeding programs. The Authorized Departmental Officer's Designated Representative monitored activities of project through frequent phone calls and emails, two formal meetings, site visits, and through quarterly reports.