Location: Soybean and Nitrogen Fixation ResearchTitle: Assessing water-related plant traits to explain slow-wilting in soybean PI 471938
|BAGHERZADI, LALEH - North Carolina State University|
|SINCLAIR, THOMAS - North Carolina State University|
|ZWIENIECKI, MACIEJ - University Of California|
|SECCHI, FRANCESCA - University Of California|
|HOFFMANN, WILLIAM - North Carolina State University|
|Carter Jr, Thomas|
|RUFTY, THOMAS - North Carolina State University|
Submitted to: Journal of Crop Improvement
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2017
Publication Date: 5/4/2017
Citation: Bagherzadi, L., Sinclair, T., Zwieniecki, M., Secchi, F., Hoffmann, W., Carter Jr, T.E., Rufty, T. 2017. Assessing water-related plant traits to explain slow-wilting in soybean PI 471938. Journal of Crop Improvement. 31:400-417.
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 is a more cost effective means to address the problem. In this study we investigate the underlying physiological bases for the drought tolerance exhibited by exotic soybean accession PI 471938 from Nepal. It turns out that the mechanism of tolerance in this soybean germplasm is complicated rather than simple. The research communicated here will be the foundation of future studies which will seek to unravel the mechanism of drought tolerance possessed in the exotic soybean. We believe that this information will be of great interest to readers to the general agricultural and breeding communities.
Technical Abstract: Exotic soybean accession PI 471938 from Nepal expresses a slow-wilting phenotype in the field, and the progeny of this genotype have been shown to have high yield under water-deficit conditions. However, the physiological basis for the slow-wilting trait in PI 471938 remains unclear and failure to understand the causal mechanism may limit future breeding efforts. This study investigated three primary hypotheses for constitutive trait expression that could explain slow-wilting trait in PI 471938: (1) a low osmotic potential in the leaves allowing greater water retention, (2) low elastic modulus of leaves resulting in delayed development of wilting, and (3) low hydraulic resistance allowing rapid water redistribution in the plants. Experiments included three other soybean genotypes as references for the results obtained with PI 471938. Surprisingly, the results for PI 471938 did not prove to be unique as compared to the other three tested genotypes for any of the three hypotheses. These negative results indicate that an hypothesis outside the usual candidates describing plant water transport, possibly anatomical features related to specific water transport properties, is required to explain slow-wilting in PI 471938.