GENOTYPIC VARIATION TOR FATTY-ACID CONTENT IN SELECTED GLYCINE-MAX X GLYCINE-SOJA POPULATIONS

Modifications in the fatty acid composition of soybean [Glycine max (L .) Merr.] oil may extend its utility to industrial markets currently s erviced by other vegetable-, mineral-, or fossil-based oils. However, extension into nov markets depends on the development of soybean oils with increased concentrations of saturated, monounsaturated, or polyun saturated fatty acids. Three wild soybean (G. soja Siebold & Zucc.) ac cessions possessing unique fatty acid profiles were intercrossed with the reduced saturate and polyunsaturate fatty acid germplasm, N87-2122 -4, to produce widely segregating populations, Random F-2 and F-2:3 fa milies from each population were grown, and seed fatty acid contents o f individuals within families were analyzed. Genotypic differences for oil quality were significant among populations and families within po pulations, Individual families produced >140 and 175 g kg(-1) palmitic ,md total saturated fatty acid contents, respectively, No family produ ced greater oleic acid content than N87-2122-4. Some families produced >640 g kg(-1) linoleic acid and total polyunsaturates exceeding 720 g kg(-1), while selected individuals produced >750 g kg(-1) total polyu nsaturates in both the f(2:3) parental and F-2:4 progeny generations, High narrow-sense heritability estimates for palmitic (h(2) = 0.67 to 0.98) and linoleic (h(2) = 0.44 to 0.80) acid contents suggested that individual F-2 plants can be selected for either trait. However, the s maller heritabilities for oleic (h(2) = 0.36 to 0.66) and linolenic (h (2) = 0.10 to 0.47) acid contents necessitate selection based on famil y means. Analyzing these selected wild soybean crosses has demonstrate d G. soja mar be a useful source of genes to extend genotypic variatio n for linoleic and total polyunsaturated fatty acid contents. Genes fo r greater saturate content in PI 424031 may extend variation currently available in mutant soybean germplasm. However, it appears unlikely t hat G. soja would be useful for increasing oleic acid content above le vels in existing soybean mutants.