Hildebrand and Hymowitz (1980a) reported that two soybean genotypes were found that lack detectable seed a- amylase activity . The cultivar \u27Chestnut\u27 produces an inactive a- amylase protein, Span (Hildebrand and Hymowitz , 1980b) ; \u27Altona\u27 is a mixture of genotypes that have a a-amylase protein of normal activity (sp1b) or lack it entirely (sp1) (Hildebrand and Hymowitz , 1980b) . Chestnut was selected from \u27Habaro\u27 and introduced into the U.S. as PI 20,405 in 1906 from Kharbarovsk, USSR (Hymowitz et al ., 1977)
