Department of Plant Sciences

Soybean [Glycine max (L.) Merr.] is one of the most important vegetable and oilseed crops with an annual value of over 36 billion dollars in the U.S. Soil Zn deficiency can reduce soybean yield and quality; therefore identifying Zn efficient genotypes can offer a sustainable solution to this problem. Furthermore, a reliable method for screening soybean lines would be useful for breeders. The main objective of this study was to detect genotypic variation in soybean under low Zn stress. This was accomplished by using physiological variables including biomass, leaf area, chlorophyll content, stomatal conductance, and shoot nutrient concentration. Ten soybean genotypes were subjected to low Zn availability (1 pM) with chelate buffers in hydroponics. Visual symptoms of Zn deficiency were evident at 21 to 28 d after treatment. Compared to sufficient Zn, low Zn conditions significantly affected four of ten genotypes. Additionally, low Zn reduced leaf area, chlorophyll, shoot Zn, and Fe concentration. The genotypes that proved more Zn efficient were “Williams” and “Pella86”. These genotypes had higher leaf area, chlorophyll, and leaf nutrient content such as Zn and N. This research demonstrated considerable genotypic variation among soybean genotypes that may be selected for Zn efficiency based on a hydroponics screening. More Zn efficient genotypes identified in this study may be used to prevent field yield losses where soil low Zn availability is a problem.