In the progeny of a hybrid obtaned after crossing local Polish and local Bulgarian white clover genortypes one octoploid (2n=64) plants was selected.In view of difficulties to obtain seeds, the octoploid plant was vegetatively propagated.The progeny of the octoploid obtained as a results of self-and-cross-pollination of cloned plants was examined and compared to related tetraploids with respect to morphological characters, fertility and embryo sac structure.Vegetative and generative organs of the octoploid were slightly larger than those of tetraploids.The number of flowers per head was larger in the octoploid than in tetraploid plants.The spontaneous octoploid appeared to have a low fertility after both cross- and self-pollination.It was most probably caused by low polen viability, by decline of megasporocyte and megagametocyte in the process of ontogenesis and by smaller ovule number per ovary.Seeds of octoploids were partially under developed and only 23.85% of them gave rise to seedlings.
Anthocyanin spot on the leaves of red clover is inherited indepently of light spot and uniform leaf colour.The gene determining anthocyanin spot is probably localized on the other chromosomes than the gene determining light spot on the leaves.A short flower tube is also determined by a single recessive gene of a pleiotropic action.It stimultaneously causes reduction of pistil style, thickening of the endithecium layer in anthers - entails their indehiscence, pollen grain-agglutination and often deformation, no division of part of pollen grains into a vegetative and generative cells as well as germination of a single grains in pollen sacks.The changes in the structure of endothecium and pollen grains cause almost complete male and female infertility of plants with short flower tubes.
The studies focused on the mechanism of autotetraploid plant occurrence in a hybrid progeny obtained from crossing geographically distant white lupin subspecies.It has been found that autotetraploid plants occurred : a) parthenogenetically - through dupllication of chromosome number in an unreduced megaspore; b) amphimitically - due to duplication of chromosome number in part of somatic cells: in sectors with a doubled chromosome number there occur 2n gametes.Tetraploid plants occurred parthenogenetically died in the next generation, wheres those occurred amphimitically on chimera plants appeared to be viable.Autotetraploid plants in comparison to diploid forms flowered and matured later were less fertile and characterized by larger seeds.
The inheritance of light-cream coloration of vegetative part in yellow lupin plants was studied. It was found that this trait is inherited monomerically.In homozygous system the gene responsible for light-cream coloration has a plieotropic action.Among others it causes a lower fertility and reduction of seed yield per plant.In heterozygous system symptoms of heterosis are observed.In many aspects of action of dilutus gene is similar to that of dwarf gene in yellow lupin previously described by the autors of this paper.
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