MOLECULAR ASPECTS OF CYTOPLASMIC MALE-STERILITY IN PERENNIAL RYEGRASS (LOLIUM-PERENNE L) - MTDNA AND RNA DIFFERENCES BETWEEN PLANTS WITH MALE-STERILE AND FERTILE CYTOPLASM AND RESTRICTION MAPPING OF THEIR ATP6 AND COXI HOMOLOGOUS REGIONS

Lolium perenne L. male-sterile and fertile cytoplasms contain different mitochondrial genomes, as revealed by Southern hybridization with a number of heterologous mitochondrial probes. In addition, transcriptional patterns of atp6 and coxI genes distinguish both cytoplasmic types. The majority of the L. perenne sequences from male-sterile and fertile cytoplasm showing homology with these two genes has been cloned and mapped by restriction digestion. A complex genomic organization, especially concerning coxI homologous sequences, was found in the male-sterile cytoplasm. Furthermore, during the course of these studies tissue-culture-induced mtDNA mutations in a number of coxI-containing sequences were detected in regenerated plants.