Campanula Rapunculoides Research Articles

Inbreeding depression in Campanula rapunculoides L. I. A comparison of inbreeding depression in plants derived from strong and weak self-incompatibility phenotypes

Abstract The evolution of selfing taxa from outcrossing ancestors has occurred repeatedly and is the subject of many theoretical models, yet few empirical studies have examined the immediate consequences of inbreeding in a population with variable expression of self-incompatibility. Because self-incompatibility breaks down with floral age in Campanula rapunculoides, we were able to mate outbred and selfed maternal plants in a crossing design which produced progeny with inbreeding coefficients of 0, 0.25, 0.50 and 0.75. Cumulative inbreeding depression in plants that were selfed for one generation was very high in families derived from strongly self-incompatible plants (average δ = 0.98), and somewhat lower in families derived from plants with weaker expression of self-incompatibility (average δ = 0.90). Relative to outbred progeny, inbred progeny produced fewer seeds, had lower rates of germination, less vegetative growth and fewer flowers per plant. Inbred progeny also took longer to germinate, and longer to produce a first leaf and to flower. Interestingly, inbred plants also produced 40% fewer seeds than outcrossed plants (t-test P < 0.001) even when mated to the same, unrelated pollen donor, suggesting that inbreeding can produce profound maternal effects. Most importantly, our results demonstrate that progeny derived from plants with stronger expression of self-incompatibility exhibited greater levels of inbreeding depression than progeny from plants with weaker expression of self-incompatibility. Moreover, the decline in fitness (cumulative, ln-transformed) over the four inbreeding levels was steeper for the progeny of the strongly self-incompatible lineages. These empirical results suggest that inbreeding depression and mating system phenotype have the potential to coevolve.

Phenotypic plasticity in the expression of self-incompatibility in Campanula rapunculoides

Plants with self-incompatibly (SI) frequently exhibit variable expression of this trait. The study reported here investigates the breakdown of SI in a perennial bellflower (Campanula rapunculoides) using a standard quantitative genetics approach to examine the relative influences of genotype, prior fruit-set and floral age on seed-set from self-pollinations with standardized pollen loads. Cross-pollen was used on separate flowers for comparison. The results obtained indicate that genotype (clone) explained a significant amount of the total variation and plants with few developing fruits showed stronger expression of SI on young flowers, and weaker expression of SI on old flowers than plants with many fruits (fruit-by-floral-age interaction, P<0.02). A second experiment determined that the stigmatic curling accompanying floral age does not influence expression of SI. A significant clone-by-floral-age interaction suggests that continuous variation in self seed-set of putatively SI species may be the result of genotype-by-environment interactions. It is concluded that SI is a phenotypically plastic trait in C. rapunculoides and its breakdown responds to conditions that are indicative of low pollinator activity.

Phenotypic plasticity in the expression of self-incompatibility in Campanula rapunculoides

Phenotypic plasticity in the expression of self-incompatibility in Campanula rapunculoides

Polymeric adsorbents of the affinity type in the investigation of physiologically active substances

The possibility of separating the components of the polyphenolic compounds of creeping bellflower Campanula rapunculoides L. on the adsorbent morin-azophenylsulfonylethoxyethyl-Spheron by the method of nonclassical low-pressure affinity chromatography has been studied. It has been shown to be feasible to separate phenolcarboxylic acids and flavone glycosides and aglycons.

Pollen Removal and Pollen Deposition Affect the Duration of the Staminate and Pistillate Phases in Campanula rapunculoides

We examined factors affecting the duration of the staminate and pistillate phases in the protandrous flowers of Campanula rapunculoides L. (Campanulaceae). Under conditions of natural pollinator visitation, flowers experiencing low rates of pollen removal lasted significantly longer than flowers that had faster rates of pollen removal. Experimental manipulations showed that low levels of pollen removal resulted in extension of the staminate phase. Hand-pollinations in which we varied the amount and source of pollen showed that when the number of fertilized ovules within an ovary is low, senescence of the flower is delayed, resulting in extension of the pistillate phase. We also report on pollinator foraging patterns within the vertical inflorescences of C. rapunculoides and the limiting factor for seed set in this population. The results are relevent to recent suggestions that floral characters often serve to reduce interference between the sexual functions in cosexual plants.

Phenolic Compounds in Soil as Influenced by the Growth of Different Plant Species

(1) The amounts of six phenolic compounds (p-hydroxybenzoic, vanillic, p-coumaric and ferulic acids, p-hydroxybenzaldehyde and vanillin), released by four extractants, differed considerably between soils from fourteen plots on which four graminaceous species, eight dicotyledonous species and two species of the Pteridophytes had been grown individually for 16 yr. There were also large differences in the amounts of the phenolic compounds extracted from the roots of these species. (2) When expressed in terms of #g phenolic compound g-1 organic C, differences between the roots were greater than differences between the soils. Also the amounts extracted by water from the roots (after freeze-drying and grinding) were much greater than the amounts extracted from the soils. The amounts extracted by 2 M NaOH were, in general, greater from the roots than from the soils and, with p-coumaric and ferulic acids from the graminaceous species, much greater. However, in instances where the amounts extracted from the roots by 2 M NaOH were small, e.g. vanillic acid from Pteridium aquilinum, the amounts from the soils, expressed per unit of organic C, were greater than those from the roots. (3) The sum of the six phenolic compounds extracted from the soils by 2 M NaOH represented between 0-03% and 0.33% of the soil organic matter, these values referring to soils under Pteridium aquilinum and Campanula rapunculoides respectively. In thirteen of the soils, p-coumaric acid was present in greater amounts than anypof the other compounds. (4) With the possible exception of the soil under Agropyron repens, the amounts of the identified phenolic compounds extracted by water appeared unlikely to exert allelopathic effects. However, the amounts released by 0-5% Ca(OH)2 were equivalent to concentrations in the soil solution that have been reported to have adverse effects on plant growth under certain conditions, which suggests that such effects might occur in the field as a consequence of liming.

Optimum Mean Temperature for a Plant Growth Calculated by a New Method of Summation

The relationship between temperature and stem elongation has been investigated for representative herbaceous plants sampled from populations of seven species which were growing under semi—natural conditions in the Botanical Garden of the University of Padua (Italy). The growth of the floral stem was measured for the following species: Galanthus nivalis L., Corydalis cava Schw. et Krt., Anemone nemorosa l., Symphytum tuberosum L., Symphytum tuberosum L., Allium ursinum L., Aegopodium podagraria L., and Campanula rapunculoides L. Official records of daily maximum and minimum air temperatures have been elaborated by means of a new method of temperature summation. This method takes into consideration the concept that plants possess a range of sensitivity to temperature between maximum and minimum thresholds and that there is an optimal temperature for each stage of development. Data for stem elongation have been optimized (using the technique of best fit) as a function of a logistic curve which may represent growth under ideal conditions. Differences between the logistic curve and the real curve of growth may be related to the amount of deviation of values for environmental factors form optimal values. The temperature ranges between 0° C and 30° C which gave the best correlations with stem elongation have been calculated for the entire period of this process of growth. The average between the two thresholds on each day has been considered as the optimum mean temperature for that day. The optimum mean temperature increases from the start of the process to ripening, with the exception of a period just before flowering when all plants seem to require lower daily temperatures. The results of this analysis have also indicated that unknown factors other than temperature are affecting stem elongation.

Life Cycle and Temperature Requirements of Seven Herbaceous Species

Abstract A series of observations were made on the life cycle, phenology, and germination capacity of Galantbus nivalis L., Corydalis cava Schw. et Krt., Anemone nemorosa L., Symphytum tuberosum L., Allium ursinum L., Aegopodium podagraria L., and Campanula rapunculoides L. The studies were conducted in field, in the Arboretum of the Botanical Garden of Padua, in experimental field chambers, and in growth cabinets maintained at temperature of 4°, 15° and 25°C. The various stages of life cycle of plants require different optimal thermoperiods. High temperature induce dormancy in A. nemorosa and S. tuberosum, while in G. nivalis and A. ursinum the rest period at the end of the vegetative cycle, is not broken by temperature treatments. A. podagraria and C. rapunculoides respond with a different morphogenesis to different temperatures. Temperature change (in the controlled conditions from one constant temperature to another) induced subsequent stage development. Vernalization is essential for all the species under study. However the minimum temperature for vernalization and the duration of exposure at this temperature varies in different species. The life cycle observed of the various species may be considered as examples of different types of adaptation to a same environment.