L. IN THE MIDDLE RUSSIA (VARIABILITY AND HERITABILITY OF BIOMORPHOLOGICAL FEATURES)

Abstract

The taxonomy of the genus Bidens L. still remains quite confusing. Indigenous European species are polymorphic and include many forms and varieties. Species diversity of alien samples of bur-marigold is treated by different authors ambiguously; taxonomic rank of plants with intermediate characteristics is unclear. In this connection there is a need to study the variability and heritability of morphological characters of different taxa series by experimental methods. Complex of Bidens taxa growing in Moscow and Vladimir regions has been studied. Seeds of 7 different taxa were sowed in experimental plot for estimating the heritability of biomorphological characters. Variability of the growth rate, phenorhythm, stomata’s characters, morphology of generative organs, morphometric characters of pollen grains and seed’s production were determined for the F generation. The illegality of segregating B.tripartita f. minima was postulated, because small size isn’t inherited and depends on adverse growing conditions. On the other hand, gigantism sign in B.tripartita is inherited to some extent, probably due to the larger achenes of parental species. Two varieties of B.connata which differ in heritable morphological characters and adaptation to different soil moisture have been identified.