2012 Annual Report
1a.Objectives (from AD-416):
To develop high yielding drought tolerant cultivars adapted to Arkansas and other drought-prone U.S. environments.
1b.Approach (from AD-416):
Soybean germplasm will be screened to identify drought tolerance. Putative tolerant types will be verified. Genetics of the tolerance will be investigated. Drought tolerance genes, as found, will be transferred to adapted cultivars. This work will be pursued in lab, greenhouse, and field studies.
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. Special genes for drought tolerance, bred into soybean so 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 in soybean to work on U.S. farms. To that end, the United Soybean Board's drought tolerance project coordinates the research activities of 8 scientists and 7 research institutions in the Midwest and South. This effort is aimed at transferring drought genes from exotic Asian material into adapted genetic materials which will protect agriculture from damaging droughts.
In the first years of the project, novel genetic drought tolerant resources were found in later maturing southern types. As this research matured, the drought tolerance trait was transferred first to Southern breeding lines and then moved north to Midwestern breeding lines. More recently, new discoveries have occurred in exotic materials of Midwestern maturity. Drought tolerance from these Midwestern maturity types is being transferred to Midwestern breeding lines now and will soon be transferred to Southern breeding lines as well. This national rather than regional approach to drought has ensured a great cross fertilization of science, using advances in one region to spur advances in the other.
An important aspect of the drought tolerance project in Arkansas is to introgress the drought tolerant nitrogen fixation trait from diverse germplasm into an adapted southern background. Two advanced breeding lines were released which have this trait. Additional exotic material from the USDA germplasm collection have now been identified which have even more drought tolerance in terms of sustained nitrogen fixation, than do the originally discovered sources. Inheritance studies and quantitative trait loci (QTL) mapping of this trait is underway. Over 200 new breeding lines are being evaluated for drought tolerance in 2010, 2011 and 2012. QTL for slow wilting were discovered.