Genotypic variation among Glycine spp. for ability to acclimate to saturated soil

Abstract

The ability to acclimate to, and grow well under saturated soil culture conditions (SSC) is a ubiquitous trait in soybean (Glycine max) but little information has been reported about this novel adaptive trait in wild Glycine spp. The ability of 39 diverse accessions from one wild annual and eight wild perennial Glycine spp. to acclimate to, and grow in SSC was therefore evaluated, and responses compared with those of three cultivars of soybean. Plants were exposed to SSC 26 days after sowing, and measurements made, after a further month, of the number of nodules, leaf area, and dry matter accumulation of roots, stems and leaves. None of the wild perennial Glycine spp.(subgenus Glycine) acclimated to SSC. Necrotic tissue developed in some perennial accessions as soon as six days from the imposition of SSC, and all of the perennial accessions died during the experiment. In contrast, both of the annual species within subgenus Soja (soybean, and its presumed wild progenitor, G. soja) acclimated to SSC. The subsequent rate of recovery tended to be slower in G. soja than soybean. The responses are consistent with the hypothesis that the ability to acclimate to SSC is a wild-type trait, expression of which was amplified in soybean during domestication in rice-based agriculture.