Beta section Beta : biogeographical patterns of variation, and taxonomy

摘要: In Chapter 1 an account is given of the historical subdivision genus Beta and its sections, relations sections are discussed. Emphasis to taxonomic treatment wild section by various authors. The Linnaean names B. vulgaris L. maritima lectotypified, resp. neotypified as a basis for new classification section. Based on experimental evidence described in Chapters 2 3 conclusions drawn with respect Beta. revision acknowledges three species, including vulgaris, macrocarpa patula. subdivided subspecies. subsp. preserved cultivated beets. Wild forms classified vulgar adanensis. number infraspecific taxa extensively reduced. minor variants botanical variaties abandoned. morphological similarities differences between discussed geographical variation analysed. Plants from wide origin grown under uniform conditions evaluated simultaneously. Species relationships shown through multivariate cluster analysis principal component 79 OTUs 19 variables. allelic isozymes species evaluated. A selection 76 accessions was surveyed allozyme variability. total 11 isozymes, all polymorphic at least one locus, were studied. Genetic variability coefficients calculated based 59 9 loci. greatest diversity met originating Mediterranean Basin. Generally, patula, adanensis express same allozymes maritima. patula could be characterised expression specific high frequencies. has diverged loci notably Lap1, Acp1, Pgm2 Px2. low (H e = 0.01) 0.07). sensu lato H 0.28 or more. Interspecific levels observed heterozygosity related breeding system. macrocarpa, expressed confirming self-compatibility. higher level heterozygotic genotypes pointed allogamous, reproduction presence common rare investigated. Allozymes more less restricted regions Acp1 -7 (primarily ), Mdh1 -1 Greek Sicilian en Lap1 -5 ) -2 (subsp. , Atlantic only, ). Mdh1-3 frequency, but dispersed over entire distribution area. particular suggested close relationship It concluded that quantification intrapopulational description patterns offered useful information sampling beet populations. Regarding it essential sample many populations possible different environments possible. genetic equally divided individual plants population neighbouring Differences weak. 4 life cycle flowering time affiliated described. effect external parameters initiation such vernalization daylength representative origins. requirement demonstrated north regions. Although affected bolting nearly accessions, noted response upon variable: after complete only Brittany, France. Netherlands Irish south coast responded incomplete season subsequent vernalization. seemed highly insensitive vernalization, since even absent Thus, need sensitivity seem follow - cline. bolt readily without show strongly reduced period vegetative growth. needs long days both flowering, bolts short day conditions, cannot flower conditions. flowers seems obligatory annual taxon 5 germination behaviour relation seed dormancy. dormancy tested exposing variously pretreated fruit balls (glomerulae) temperature regimes. pattern ssp. analysed part distribution, belonging gene pool. Fruit northern showed optimum range temperatures 20° 30°C. Freshly harvested almost no 10° 15°C. Stratification enhanced gerniination lower temperatures. optimal temperature, 30°C most tested. sensitive effects germination. also describes ecology . Seed does not controlled, instead mechanical fac tors may limit Compared s.l. penetration moisture this difficult, operculum fixed tightly pericarp, preventing easy protrusion radicle. 6 germplasm collection Accessions Sicily controlled morphometrically. Geographical characters identified putative into coastal inland reassessed. Between adjacent significant found Petiole length, Leaf width Biomass, however variable unambiguously reflected pattern. Overall small. length rate generative development important distinguishing these groups. Interferences how rationalized avoid excessive duplication.