Mitochondrial Genetics of Alloplasmic Male-Sterile Brassica napus Lines

摘要: Reliable and economical production of hybrid (F1) varieties requires efficient means to control pollination. The predominant system for pollination most field crops today is cytoplasmic male sterility (CMS). Since CMS a consequence disturbed nuclear-mitochondrial interactions, the trait maternally inherited. A common way produce plants combine nuclear genome from one species with mitochondria another; such origin are described as alloplasmic CMS. This thesis describes molecular characterization novel produced rapeseed (Brassica napus) (+) Arabidopsis thaliana somatic hybrids. population 170 B. napus A. lines was backcrossed 22 and/or aberrant flower morphology were found. Nine these analysed RFLP found contain plastid DNA napus, whilst mitochondrial genomes frequently recombined containing both DNA. Besides male-sterile trait, majority displayed homeotic conversions anthers carpeloid organs. Vegetative growth reduced some extent in lines. One line segregated fertile sterile plants. Fertility co-segregated markers chr III. By dihaploidisation strategy we disomic addition III, which had stable inheritance phenotype. Global mRNA expression fertility-restored line, corresponding thaliana. Run-on experiments showed that transcriptional activities highly variable between activity several ribosomal protein genes increased orf139. Steady-state levels more homogenous comparison showing RNA turnover an important regulatory mechanism. Increased transcript abundance observed often correlated presence longer transcripts. Transcripts three loci, orf139, orf240a orf294 accumulated but restored line. orf139 transcripts differentially tissue genotype-specific manner, while constitutively expressed throughout plant. Both can be polyadenylated, thus providing explanation their post-transcriptional regulation. Segregation analysis indicates less likely candidates responsible phenotype, whereas CMS-associated. However, it than locus mt-DNA could encode background napus.