Genetic analyses of two independent chlorophyll-deficient mutants identified among the progeny of a single chimeric foliage soybean plant

Chimeric (variegated) foliage plants are frequently observed in many specie s. In soybean [Glycine max(L,) Merr,], progeny of chimeric plants are a sou rce of nuclear and cytoplasmically inherited mutants. Self-pollinated proge ny of a single chimeric plant derived from tissue culture of PI 427099 (Jil in 3) included plants with green foliage, chimeric foliage, yellow foliage (viable), and yellow foliage (lethal), Our objectives were to determine (1) inheritance, linkage, and allelism of the lethal-yellow mutant with known chlorophyll-deficient mutants; (2) inheritance, linkage, and allelism of th e viable-yellow mutant with known chlorophyll-deficient mutants; (3) alleli sm of the lethal-yellow mutant with the viable-yellow mutant; and (4) male and female gamete transmission of the viable-yellow mutant trait. The viabl e-yellow mutant was allelic to T323, y20 y20 (Ames 2) Mdh1-n Mdh1-n (Ames 2 ) and was assigned genetic type collection number T361 and gene symbol y20 y20 (Ames 24) Mdh1-n Mdh1-n (Ames 22), The lethal-yellow mutant was allelic to T225H (Y18 y18) and was assigned genetic type collection number T362H a nd gene symbol Y18 y18 (Ames 2), T225H became Y18 y18 (Ames 1), The two chl orophyll-deficient mutants were not linked to each other. There was no sign ificant difference in F-1 male or female gamete transmission of the viable- yellow mutant. However, many cross-combinations gave significant deviations from the expected 3 green plants:1 viable-yellow plant in the F-2 generati on. The allelism of these two chlorophyll-deficient mutants with mutants T2 25H and T323, derived from putative transposable element systems, is intrig uing. An explanation of this phenomenon awaits molecular experimentation.