Embryogenic response of multiple soybean [Glycine max (L.) Merr.] cultivars across three locations

Nine soybean [Glycine max (L.) Merr.] cultivars representing midwestern, mi d-south, and southern US growing regions were evaluated at each of three lo cations (Athens, GA; Lexington, KY; and Wooster, OH) using uniform embryoge nic induction and proliferation protocols in order to evaluate the portabil ity of soybean somatic embryogenic protocols to different locations. The ex perimental design minimized variation between locations by having all culti vars present at all locations on all days. A quantitative weighted score fo r primary embryo induction was developed on average embryo number per expla nt and was used to describe non-embryogenic, poorly embryogenic, moderately embryogenic, and highly embryogenic responses. Ranking of cultivars remain ed similar across all locations, indicating a uniform transportability of t he protocol, at least as far as embryo induction is concerned. Continued pr oliferation of embryogenic cultures was also measured using a repetitive gr owth measure but few meaningful conclusions could be made due to the high l evel of variability including inconsistent growth of cultures between each subculture. Overall, several cultivars were identified as being uniformly e mbryogenic or non-embryogenic at the primary induction phase at all locatio ns, and we predict that those embryogenic cultivars could be used by any la boratory for high-efficiency induction of embryogenesis. The best of these cultivars, 'Jack', was uniformly responsive across all locations and should be selected as the genotype most likely to yield positive results when att empting to culture and genetically engineer soybeans via embryogenic protoc ols.