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Premise of research. Polyploidy, a major evolutionary process in flowering plants, is expected to 19 impact floral traits which can have cascading effects on pollination interactions, but this may 20 depend on selfing propensity. In a novel use of herbarium specimens, we assessed the effects of 21 polyploidy and mating system on floral traits and the pollination niche of 40 Brassicaceae 22 species. 23 Methodology. We combined data on mating system (self-compatible or self-incompatible) with 24 inferred ploidy level (polyploid or diploid) and use phylogenetically controlled analyses to 25 investigate their influence on floral traits (size and shape) and the degree of pollination 26 generalism based on the frequency and the richness of heterospecific pollen morphospecies 27 captured by stigmas. 28 Pivotal Results. Flower size (but not shape) depended on the interaction between ploidy and 29 mating system. Self-incompatible polyploid species had larger flowers than self-incompatible 30 diploids but there was no difference for self-compatible species. The breadth of pollination niche 31 (degree of generalism) was not affected by ploidy but rather strongly by mating system only. 32 Self-incompatible species had more stigmas with heterospecific pollen and higher heterospecific 33 pollen morphospecies richness per stigma than self-compatible species, regardless of their 34 ploidy. 35 Conclusions. Our results demonstrate that mating system moderated the influence of ploidy on 36 morphological features associated with pollination generalism but that response in terms of 37 heterospecific pollen captured as a proxy of pollination generalism was more variable.
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Effect of plant tissue culture parameters on the ploidy level of Physalis grisea, Solanum lycopersicum , and Solanum prinophyllum regenerants
Abstract Plants regenerated from seedling explants (hypocotyls and cotyledons) of the Solanaceae family membersPhysalis grisea(groundcherry),Solanum lycopersicum(tomato), andSolanum prinophyllum(forest nightshade) were used to determine the in vitro culture parameters that contribute to the incidence in polyploidization of tissue culture-derived plants (regenerants) from these species. We examined the possible effects of zeatin concentration in the plant regeneration medium, explant source, and species. Plants were grown to maturity under greenhouse conditions, pollen was collected and germinated. Flow cytometry analysis verified the utility of the pollen germination method for determining differences in ploidy, which was based on the number of pollen tubes produced with one tube representing diploid and two indicating polyploid. As for zeatin concentration, we assessed the effect of our standard method of initiation on medium containing 2 mg/l followed by 1 mg/l 2 weeks after culture initiation in comparison with 0.25, 0.5, and 1 mg/l throughout the culture lifetime. There were no major correlations for zeatin concentration on ploidy status across the species except for plants regenerated fromS. lycopersicumhypocotyl explants where the percentage of polyploid regenerants increased with increasing concentrations. As for species and explant effects,P. griseaplants regenerated from hypocotyl explants had the highest percentage of polyploid plants at 81% compared to 43% and 35% forS. lycopersicumandS. prinophyllum, respectively. From cotyledons, 8% ofS. lycopersicumand 20% ofS. prinophyllumwere polyploid. A comparison withP. griseacould not be made because cotyledon explants do not regenerate on zeatin-containing medium. The results indicated the incidence of polyploidization cannot be generalized for zeatin concentration, however, an influence of explant type and species was observed. Effects of increased ploidy on plant morphology were primarily larger flower and seed size; however, no significant differences were observed in plant or fruit size.
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- Award ID(s):
- 2216612
- PAR ID:
- 10590917
- Publisher / Repository:
- bioRxiv
- Date Published:
- Format(s):
- Medium: X
- Institution:
- bioRxiv
- Sponsoring Org:
- National Science Foundation
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- https://doi.org/10.1101/2025.05.01.651681
