[Epigenetic variation of the choriflowered--symflowered character in the symflowered sugar beet line SOAN-14].

The effect of 5-azacytidine on the variation of the choriflowered (CF)-symflowered (SF) character in sugar beet was studied in several generations obtained via seed reproduction. The epimutagen (5-azacytidine) significantly reduced the number of flowers in glomerate inflorescences in the year of seed treatment and in the next generation (Az1), leading to the appearance of plants with single flowers in bract axils of a flower stalk. The CF character resulting from epimutagene treatment of sugar beet seeds (plants with genotype M(Z)M(Z) was inherited as a monohybrid character in both zygotic and apozygotic seed progenies.

[Fruit set variation associated with apozygotic reproduction in sugar beet (Beta vulgaris l.)].

Fruit set upon apozygotic reproduction was studied for four years in the msSOAN-5 pollen-sterile inbred sugar beet line. The progenies obtained from pollen-sterile plants by apozygotic reproduction had both fruits with normal seeds and parthenocarpic fruits without seeds, which was not an occasional event. Growth conditions proved to strongly affect the fruit set and seed quality.

[Analysis of serial sequences of seeds in sugar beet plants upon apozygotic reproduction].

Dichotomic serial sequences of fruits of two types (with and without seeds) on shoots were analyzed in sugar beet upon apozygotic reproduction. Serial sequences were analyzed using serial statistical tests. The distribution of fruits of the two types was nonrandom in most cases.

[Effect of 5-azacitidine on flower stalk branching in sugar beet (Beta vulgaris L.)].

An influence of epimutagen 5-azacitidine on a flower stalk morphogenesis in sugar beet was studied. After the epimutagene treatment the great number of the first- and the third-order branch formation was observed. A higher level of branching completely modified the flower stalk architectonics (generations A0Az0 and A1Az1).

[Effect of the epimutagen 5-azacytidine on the structure of floral-stalk metameres in sugar beet (Beta vulgaris L)].

This study is dedicated to the effect of the epimutagen 5-azacytidine on the structure of floral-stalk metameres in sugar beet Beta vulgaris L. Simple phytomeres consist of separate flowers (unianthous plants; UA phenotype), while complex metameres occur in synanthous plants (SA phenotype). Treatment of the synanthous line mcSOAN-5 dramatically reduced the number of flowers on phytomeres as early as in generation zero (A0Az0).