effects in potato and behaviour of different plastid-mitochondrial configurations
in fusion hybrids
Symmetric somatic cell fusion allows in the presence of nearly isogenic
nuclear genomes to estimate the contribution of plasmones to yield parameters.
Distinct mitochondrial (mt) and chloroplast (cp) genomes were combined
in tetraploid hybrids of potato.
Analysis of mt-cp configurations in 144 potato cultivars [2n=4x], a
reciprocal population [2n=2x], 2x fusion parents [2n=2x] and their respective
hybrids [2n=4x] made visible the effects of different cytoplasmic backgrounds
and mitochondrial subgenomic rearrangements.
Evaluation of cytoplasmic types lead to the assumption, that in starch
content the ´wild type´ cytoplasms a
and g have
a significant advantage to other Cytoplasmic types (b,
This results from the experiments with a reciprocal population, 180
di-haploids, and from cultivar comparisons. Genotypes identified by our
markers as mt type g were
associated with cytoplasmic male sterility. In seed production di-haploids
with mt-e were
superior to others.
In hybrids a correlation of starch content with different mt-cp combinations
could be found.
In general these cytoplasmic configurations which appeared to a high
frequency within a population, were associated with the highest field performance.
This fact is explained by a selection advantage of clones with optimized
organellar segregation allready during in vitro phase.
Andreas LÖSSL, 15.04.2010