Seed of mutants from the Soybean Type Collection

Pleiotropy or close linkage of two mutants in soybeans ABSTRACT: Genetic studies were undertaken of soybean (Qlyclne max [L] Merr.) mutant T253, which is chlorophyll deficient and has tan-saddle-pattern seed. The chlorophyll-defi-cient allele was tested against eight nuclear chlorophyll-deficient mutants and was found nonallelic; It was assigned gene symbol /so- The tan-saddle allele was identified previously as l<2- Mutant y2o-f<2 was n ° t located on trlsomics A, B, or C, and l<2 was not linked to the breakpoint of a homozygous chromosome interchange from PI 101.404B. No linkage was detected between y2o-^2 or k2 and seven mutants that were not chlorophyll deficient. About 25 000 F2 and F3 plants were classified, but y ^ could not be separated genetically from k2. The lack of crossover genotypes Indicated either that the genes are tightly linked or that there Is a plelotroplc effect. It is suggested that the mutant phenotypes were the result of a small chromosomal deletion