Nuclear genetic transformation and a restriction fragment length polymorphism analysis of soybean [Glycine max (L) Merr] mitochondrial genetics
Agrobacterium-mediated transformation was used to introduce the maize transposable element Ac into soybean cotyledons by inoculating the cotyledon at the point of embryo axis attachment with Agrobacterium tumefaciens harboring the binary vectors PZAC1, PZAC1/R, and PZAC3. A new method of transformation was applied which requires no intermediate callus formation. Inoculation at the point of embryo axis attachment with A. tumefaciens causes the proliferation of multiple shoots which later develop into whole plants. The Ac element was detected in R0 plants by PCR and Southern blot hybridization. A transformation frequency of 24% and 10% was obtained when PZAC1 and PZAC1/R vectors were used for inoculation, respectively. The element proved to be transmitted sexually to R1 plants. The Ac element follows a Mendelian pattern of inheritance in R1 plants;Restriction fragment length polymorphism analysis of soybean mitochondrial DNA was conducted. A collection of germ plasms containing accessions of three Glycine species: max, soja, and gracilis were analyzed. The Plant Introductions and cultivars used in the RFLP screen for cytoplasmic diversity were used in the construction of isocytoplasmic lines. The cytoplasm was transferred into 2 different nuclear backgrounds of cultivars Clark 63 and Harosoy 63. Based on maize mitochondrial cloned genes and a cosmid library of Phaseolus mitochondrial genomes, the germ plasms were grouped into 6 RFLP groups;The mitochondrial-based RFLP analysis was able to detect variability within the same chloroplast RFLP groups. There was evidence for involvement of the nuclear genome in controlling the physical organization of the mitochondrial genome.