|PATHAN, S. - University Of Missouri
|LEE, J. - Kyungpook National University
|SLEPER, D. - University Of Missouri
|FRITSCHI, F. - University Of Missouri
|SHARP, R. - University Of Missouri
|Carter Jr, Thomas
|KING, C. - University Of Arkansas
|SCHAPAUGH, W. - Kansas State University
|ELLERSIECK, M. - University Of Missouri
|NGYUEN, H. - University Of Missouri
|SHANNON, J. - University Of Missouri
Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2014
Publication Date: 3/5/2014
Citation: Pathan, S.M., Lee, J.D., Sleper, D.A., Fritschi, F.B., Sharp, R.E., Carter Jr, T.E., Nelson, R.L., King, C.A., Schapaugh, W.T., Ellersieck, M.R., Ngyuen, H.T., Shannon, J.G. 2014. Two soybean plant introductions display slow leaf wilting and reduced yield loss under drought. Journal of Agronomy and Crop Science. 200(3):231-236.
Interpretive Summary: Drought is the number one limitation to soybean yield, globally.The most obvious solution to the problem, irrigation, is usually cost prohibitive. Thus, genetic improvement of the crop to better withstand drought stress is a more cost effective means to addres the problem. In this study we identified two exotic Asian soybean types as drought tolerant. They are slower to wilt than US soybean types during stress, and suffer less yield loss. These new group IV Asian types, despite their drought tolerance properties, are not well suited for direct production in the USA, because they lack diseases resistances and standability that farmers require for on farm production. US breeders are now using these Asian types as breeding stock to develop locally adapted drought tolerant varieties.
Technical Abstract: Due to high costs of irrigation, limited availability of irrigation water in many locations genetic improvement for drought tolerance is an effective method to reduce yield loss in soybean. Slow wilting and minimal yield reduction under drought are important traits in evaluating drought tolerance. Two maturity group III soybean plant introductions (PIs, PI 567690 and PI 567731) and two elite cultivars (DKB38-52 and Pana) were evaluated with and without irrigation on a sandy soil. Drought was imposed by withholding irrigation at full bloom and continued until moderate wilting was shown by the fast leaf wilting in the check cultivar, Pana. Then, irrigation was resumed until maturity. Genotypes were scored for leaf wilting during the stress period, and yields were assessed at the end of the growing season and used to calculate a drought index. Yields of the exotic PIs were lower than those of the checks under both drought and well-watered conditions. However, the PIs exhibited significantly lower wilting and less yield loss under drought (higher drought index) than check cultivars. The two PIs may have useful genes to develop drought-tolerant germplasm and cultivars and maybe useful in genetic and physiological studies to decipher mechanisms responsible for improving yield under limited water availability.