Inheritance of the Capacity for Chloride Inclusion and Chloride Exclusion by Soybeans1

Roots of Glycine max (L.) Merr. varieties absorb chloride ions in comparable amounts, but subsequent translocations of chlorides to plant tops is genetically controlled. Some varieties accumulate relatively large amounts of chlorides in plant tops; others exclude them almost completely. Chlorides occur in petioles and leaflets, with higher concentrations in leaflets, but whole leaf samples can be used to classify chloride‐accumulating capacity. The chloride includers growings in the saline soils of the Imperial Valley of California develop severe leaf necrosis from chloride toxicity, whereas the chloride excluders show no necrosis Crosses between parents with similar chloride accumulating capacity gave F2 and F3 progeny similar to parents in chloride content. In eight crosses from parents dissimilar in chloride accumulation, F2 plants segregated in ratios of 3 chloride excluder to 1 includer. In tests of the F3 progeny from these crosses, the F2 excluder plants segregated in ratios of 1 excluder to 2 segregating, whereas the F2 includer plants bred true. In backcrosses of the F1 plants from an includer by excluder cross, the segregating ratio was 1 includer to 1 segregating line when the recurrent parent was an includer and 1 excluder to 1 segregating line when the recurrent parent was an excluder. The gene symbols Nel and nel are proposed as the dominant for chloride excluders and the recessive for chloride includers, respectively.