Cytogenetical analysis of Spring soft wheat

of androclynic origin

T.M.Zolotova

Institute of Biology, Ufa Sci. Centre of Russian Academy of Sciences

Majority of cultured plants has been grown by reason of fruits and seeds which are result from genetically determing complex of interacting processes including sporo- and gametogenesis, florescence, pollination, fertilisation, embryogenesis and endospermogenesis. Features of each of these processes are determined by genome structure of species and are specific for each of variety. It is necessary to take account in selection and seed growing. The haploidy as one of atipical forms of plant reproduction attracts the attention to study main regularities of genotype formation.

Genetical features of donor plants determine ability for androclynia. It is possible the influence of genotype to regeneration ability is connected with mechanisms, functing more efficient in these lines. These mechanisms include large number of structures and functional changes. Special role of them plays genetical system’s reaction to individual adaptation towards changing conditions in comparatively shot period.

Analysis of the collection of Triticum aestivum L. varieties and their hybrids F₁ has been performed that frequency of androclynic structure s formation from hybridous combinations has complicated character of inheritance. One depends on genome s compound of parental components. According to our data strict dependence between frequency of androclynic structure’s formation from parental forms and hybrids is lacking. The wheat varieties that characterised by weak responsiveness to conditions of culture could give responsible hybrids. It is possible genes “answering” for this quality work as additive and complemented. In majority of hybridous combinations the frequency of androclynic structure s (embryoids) formation has superdominance over the better parental forms. The influence of maternal cytoplasm to this quality has been noted. The possibility of haploid formation in cultured anthers in vitro is predicted with difficulty. That is why the investigations were made to study features of florescence process of parental forms of some hybridous combinations. Differences respect to diurnal rhythm of florescence and duration of flower exposition were demonstrated.

The difference between androclynic form and hybrid for quantity of chromosome tips is showed by karyological analysis of androclynic regenerants. For instance, androclynic regenerants Московcкая 35 x Жница had five tips of chromosomes, whereas donor hybridous plants of this genotype are characterised only three tips of chromosomes. To summarise, excerpts of karyotype from androclynic regenerants are characterised by specific morphological parameters of homologous chromosomes. In general ones are characterised by great polymorphism of homologous chromosomes in comparison with plants of donor hybridous line.

The work is executed at support by the Russian Foundation for Basic Research

(Grant 99-04-48496).