NUCLEAR-CYTOPLASMIC INTERACTION IN CHLOROPHYLL-DEFICIENT SOYBEAN, GLYCINE-MAX (FABACEAE)

In higher plants, plastids and mitochondria are the predominant carrie rs of extrachromosomal genetic information. There is interplay between the plastids, the mitochondria, and the nuclear genome. In soybean, G lycine max (L.) Merr., both nuclearly and maternally inherited chlorop hyll-deficient mutants have been described. Conditional lethality prev iously was reported in soybean when maternally inherited chlorophyll-d eficient mutant (Genetic Type T275) was crossed with nuclearly inherit ed yellow foliar malate dehydrogenase null mutants (Genetic Types T253 and T323). Our objective was to test for conditional lethality when m aternally inherited yellow foliar mutants T278, T314, T315, T316, T319 , and T320 were female parents and nuclearly inherited yellow foliar m alate dehydrogenase null mutants T253 and T323 were male parents. Our results indicated conditional lethality in the F-2 generation when any of the six cytoplasmically inherited yellow foliar mutants were femal e parents and either T253 or T323 were male parents. The physiological nature of conditional lethality is not known. Data indicate a common basis in soybean for conditional lethality among the cytoplasmically i nherited yellow foliar mutants when crossed with the nuclearly inherit ed yellow foliar malate dehydrogenase null mutants. No interactions we re observed between cytoplasmically inherited or nuclearly inherited g reen seed embryo mutants as female parents and either T253 or T323 as male parents.