White-flowered Plants Research Articles

Pollinator response to yellow UV-patterned versus white UV-patternless flower dimorphism in Anemone palmata.

Flower colour polymorphisms are uncommon but widespread among angiosperms and can be maintained by a variety of balancing selection mechanisms. Anemone palmata is mostly yellow-flowered, but white-flowered plants coexist in some populations. We analysed the distribution of colour morphs of A. palmata across its range. We also characterised their colours and compared their vegetative and sexual reproductive traits, pollinator attention and fitness. The range of A. palmata is limited to the Western Mediterranean, while white-flowered plants are restricted to Portugal and SW Spain, where they occur at low proportions. Yellow flowers have a characteristic UV pattern, with a UV-absorbing centre and UV-reflecting periphery, which is absent in the white morph. Colour features of both morphs were highly delineated, making it easy for pollinators to distinguish them. Both morphs were protogynous, with the same duration of sexual stages, and the main floral traits related to pollinator attraction, apart from flower colour, were similar. Hymenoptera and Diptera were the main pollinators, showing preference for the yellow morph, clear partitioning of pollinator groups between the two colour morphs and a marked constancy to flower colour during foraging. Both morphs combined clonal propagation with sexual reproduction, but sexual reproductive potential was lower in white-flowered plants. Finally, female fitness was higher in the yellow morph. Pollinator partitioning and colour constancy could maintain this polymorphism, despite the lower visitation rate and fitness of white-flowered plants, which could facilitate their clonal propagation.

Violasuavis var. pannonica (Violaceae), a new white-flowered violet from central Europe.

Violasuavisvar.pannonica (Violaceae) from central Europe is described here as a new variety to science. It is most similar to the blue-flowered V.suavisvar.suavis and the white-flowered V.suavisvar.catalonica and V.suavissubsp.naqshii, but exhibits differences in several characters, such as petal colour, spur shape, fimbriae length on the stipules, bracteoles position on the peduncle and lamina sinus shape. Although the new taxon is often considered a colour mutation of V.suavisvar.suavis, previous genetic analyses revealed that these white-flowered plants do not arise recurrently at different locations (having multiple origins), but rather form a monophyletic evolutionary lineage. To date, the occurrence of V.suavisvar.pannonica has been reported in the Slovak Republic, the Czech Republic and western Ukraine. In this paper, we report its occurrence in Austria and Hungary. Notes on its etymology, distribution, ecology, origin and hybridization, as well as photographs of the new variety (including the holotype) are also provided.

Анализ накопления летучих органических соединений в растениях Hyssopus Officinalis L., интродуцированных в горных условиях

Introduction. Cultivation of medicinal plants in the mountains has its own characteristics due to the high ultraviolet radiation and sharp climatic fluctuations, which is important to consider when farming. In this regard, the issue of studying the accumulation of volatile organic compounds of Hyssopus officinalis L. introduced in these conditions becomes relevant. Aim. Analysis of the dependence of the content of volatile organic compounds in essential oils of 6 cultivars of Hyssopus officinalis L. ("Akkord", "Ametist", "Goluboy", "Dachnyi lekar", "Otradny", "Rozovy") and three forms of the variety "Rozovy": with white, pink and blue flowers introduced at an altitude of 1100 meters above sea level in order to determine the most valuable of them for effective cultivation in mountain areas. Research methods. The essential oils were obtained by steam distillation. The composition of volatile organic compounds was determined by chromatic-mass spectrometry on a Shimadzu GCMS-GP2010 Plus spectrometer with a mass spectrometric quadruple detector with an SLB-5 ms non polar capillary column, 30 meters long. Results. The content of essential oil in varieties ranges from 0.37 to 0.75%. Variety "Ametist" is characterized by a relatively high content of essential oil. Plants with pink flowers contain more essential oil than plants with blue and white flowers. The essential oil of the varieties contains from 31 to 37 components, while the number of major components varies between 13 and 17 compounds. A comparative study of plants of different colors according to the nature of biosynthesis in the essential oil of Pinocamphone and trans-Pinocamphone shows the following: in the essential oil of plants with white flowers, the content of Pinocamphone is observed up to 44.99%, in the blue-flowered form up to 20.85%, and in plants with pink flowers up to 45.23%. A somewhat different picture is observed in the biosynthesis of trans-Pinocamphone: the maximum proportion of this component falls on the sample with blue flowers (34.61%), significantly less in the sample with pink flowers (up to 4.43%), while white-flowered plants have none. The article presents a cluster analysis of 6 cultivars and 3 forms of the "Rozovy" variety (with white, blue and pink flowers) of Hyssopus officinalis L. according to the accumulation of volatile organic compounds. Varieties differ in the content of individual components, while β-Pinene, Pinocamphone and trans-Pinocamphone are the main plant compounds. Conclusions. As a result of the introduction of 6 cultivars of Hyssopus officinalis L. ("Akkord", "Ametist", "Goluboy", "Dachnyi lekar", "Otradny", "Rozovy") and 3 forms of the variety "Rozovy": with white, with pink and with blue flowers at an altitude of 1100 meters above sea level in identical soil-climatic mountain conditions, differences were revealed both in the accumulation of essential oils and in the biosynthesis of secondary metabolites. The data obtained can be used in laying out areas for the cultivation of Hyssopus officinalis L. for pharmaceutical and food use, which can give an additional impetus to the development of mountainous areas.

Secondary pollinators contribute to reproductive success of a pink-flowered sand verbena population.

Secondary pollinators contribute to reproductive success of a pink-flowered sand verbena population.

Standardization Techniques for Soil Mixture Ratio and Sowing Depth in Solanumvirginianum (syn. S. surattense) A Medicinal Plants of Thar Desert

It is an important constituent of well-known Ayurvedic drug “Dasmula” and “Arkadhi”. All plant parts are used in Ayurveda. The plant is very prickly diffuse, procumbent, often becomes perennial reaching a spread of a meter or so under luxuries conditions. The tap root may be very extensive in a plant, which has only few leaves. Three types of flower bearing plants, i.e. dark purple, light purple and white were observed, which differs in their density and colour. The density of white-flowered plants is very low and rarely found in natural habitats. In the present studies, it was observed that seeds of S. surattense when sown at 0.5 cm depth with 2:2:1 soil ratios of sand:clay: FYM, showed maximum seedling emergence and plant growth under nursery conditions.

Indirect Selection on Flower Color in Silene littorea.

Flower color, as other floral traits, may suffer conflicting selective pressures mediated by both mutualists and antagonists. The maintenance of intraspecific flower color variability has been usually explained as a result of direct selection by biotic agents. However, flower color might also be under indirect selection through correlated traits, since correlations among flower traits are frequent. In this study, we aimed to find out how flower color variability is maintained in two nearby populations of Silene littorea that consistently differ in the proportions of white-flowered plants. To do that, we assessed natural selection on floral color and correlated traits by means of phenotypic selection analysis and path analysis. Strong directional selection on floral display and flower production was found in both populations through either male or female fitness. Flower color had a negative indirect effect on the total male and female fitness in Melide population, as plants with lighter corollas produced more flowers. In contrast, in Barra population, plants with darker corollas produced more flowers and have darker calices, which in turn were selected. Our results suggest that the prevalence of white-flowered plants in Melide and pink-flowered plants in Barra is a result of indirect selection through correlated flower traits and not a result of direct selection of either pollinators or herbivores on color.

The effects of pollination, herbivory and autonomous selfing on the maintenance of flower colour variation in Silenelittorea.

Intraspecific flower colour variation has been generally proposed to evolve as a result of selection driven by biotic or abiotic agents. In a polymorphic population of Silene littorea with pink- and white-flowered plants, we studied pollinators, analysed flower colour perception and tested for differences in pollinator visitation. We also experimentally analysed pollinator limitation in fruit and seed set, and the degree of autonomous selfing. The incidence of florivory and leaf herbivory was compared over 3-4years. Silene littorea is mainly pollinated by bees and butterflies. Pollinators preferred pink flowers, which did not show pollinator limitation. On the contrary, white flowers showed pollinator limitation in fruit set. White-flowered plants had less floral display and higher levels of florivory than pink plants. Flower colour morphs of S. littorea can reproduce in the absence of pollinators by autonomous selfing, setting 20% and 12% of fruit and seeds in the pink morph and 27% and 20% in the white morph, respectively. Fruit set of white flowers produced by autonomous selfing did not differ from open-pollinated flowers. In conclusion, S. littorea is pollinated by insects of different orders that more frequently visit pink flowers, which is reflected in pollinator limitation of fruit set in white flowers. Moreover, this species has a mixed mating system in which both colour morphs can reproduce in the absence of pollinators by autonomous selfing, although white flowers mainly produce fruits by autogamy. We suggest that reproductive assurance by autonomous selfing helps to maintain flower colour polymorphism in this population.

Characterization and diagnostic marker for TTG1 regulating tannin and anthocyanin biosynthesis in faba bean

Condensed tannins, found in coloured-flowering varieties of faba bean (Vicia faba L) are, after vicine and convicine, one of the major anti-nutritional factors for monogastric animals. The development of tannin-free cultivars is a key goal in breeding to broaden the use of this legume in the animal feed industry. Two recessive genes, zt-1 and zt-2, control the zero-tannin content and promote white-flowered plants. Previous studies exploiting synteny with the model Medicago truncatula reported a mutation in TTG1, a gene encoding a WD40 transcription factor located in chromosome II, as the responsible for the zt-1 phenotypes. Here a comprehensive analysis of VfTTG1 (including phylogenetic relationships, gene structure and gene expression) has been conducted to confirm the identity of the gene and to reveal structural changes that may result in different functional alleles. The results confirmed the identity of the candidate and revealed the existence of two different alleles responsible for the phenotype: ttg1-a, probably due to a mutation in the promoter region, and ttg1-b caused by a deletion at the 5′end of VfTTG1. Based on the sequencing results, an allele-specific diagnostic marker was designed that differentiate zt-1 from wild and zt-2 genotypes and facilitates its deployment in faba bean breeding programs.

Habitat filtering influences plant–pollinator interactions in prairie ecosystems

The xeric hypothesis is that bees are more abundant pollinators than anthophilous flies in dry, temperate biomes, and the habitat filtering hypothesis is that differences in the proportions will impact plant community composition because different pollinators favour different floral traits. However, few studies have examined the predictive value of these hypotheses. In particular, differences in plant–pollinator compositions within biomes, such as the Prairie Ecozone, have not been compared. We documented plant–pollinator interactions and plant abundance in three Canadian prairie types. Flower visits in moist tall grass prairie were mainly by flies in the Syrphidae, whereas visits in the drier fescue and mixed grass prairie were mainly by long-tongued bees in the Apidae. Short-tongued bee visits were not significantly different between the prairie types. Insect visits to tubular, zygomorphic, violet/blue-, and white-flowered plants were higher in drier fescue and mixed grass prairie than in moister tall grass prairie. Further, proportions of plants with these features were lower in the tall grass prairie. Thus differences in the proportion of flies and long-tongued bees, likely affected by habitat conditions including moisture levels, appear to be influencing the types of plants that dominate each prairie type, providing some support for these hypotheses.

Flowering and Nectar Secretion in two Forms of the Moldavian Dragonhead (Dracocephalum moldavica L.) – A Plant with Extraordinary Apicultural Potential

Abstract Dracocephalum moldavica is a valuable reward plant for flower visitors. The aim of the study was to ecologically characterise its flowers and leaves and assess the seasonal and daily dynamics of flowering in two white- and blue-flowered forms of this species in 2004 and 2005. Additionally, the duration and abundance of plant flowering as well as the nectar amount and sugar content were analysed. The signalling attractants of the plant include an intense scent emitted by trichomes located not only on its flowers but also on its stem and leaf surfaces. The average corolla length is 24 mm and the corolla tube, which can be completely filled with nectar, is 8.6 mm long. The floral lifespan was shown to reach 2-3 days and the mean blooming duration of both forms of dragonhead 45-48 days. The white-flowered plants produced a substantially greater number of flowers (5352) than the blue-flowered form (2965). The nectar amount obtained from ten blue flowers was 15.33 mg and that extracted from white flowers reached 17.56 mg, with 49.4% and 51.5% content of sugar, respectively. The total sugar mass produced by one white-flowered plant was 4656 mg, while one blue-flowered plant yielded 2164 mg of sugars. The sugar yield calculated in the study for the white-flowered form (586 kg · ha−1) was two-fold higher than that in the blue-flowered plants.

Ecological causes and consequences of flower color polymorphism in a self-pollinating plant (Boechera stricta).

Intraspecific variation in flower color is often attributed to pollinator-mediated selection, yet this mechanism cannot explain flower color polymorphisms in self-pollinating species. Indirect selection mediated via biotic and abiotic stresses could maintain flower color variation in these systems. The selfing forb, Boechera stricta, typically displays white flowers, but some individuals produce purple flowers. We quantified environmental correlates of flower color in natural populations. To disentangle plasticity from genotypic variation, we performed a multiyear field experiment in five gardens. In controlled conditions, we evaluated herbivore preferences and the effects of drought stress and soil pH on flower color expression. In natural populations, purple-flowered individuals experienced lower foliar herbivory than did their white-flowered counterparts. This pattern also held in the common gardens. Additionally, low-elevation environments induced pigmented flowers (plasticity), and the likelihood of floral pigmentation decreased with source elevation of maternal families (genetic cline). Viability selection favored families with pigmented flowers. In the laboratory, herbivores exerted greater damage on tissue derived from white- vs purple-flowered individuals. Furthermore, drought induced pigmentation in white-flowered lineages, and white-flowered plants had a fecundity advantage in the well-watered control. Flower color variation in selfing species is probably maintained by herbivory, drought stress, and other abiotic factors that vary spatially.

Урожайность сортов гороха в конкурсном сортоиспытании в условиях Кировской области

The results of assessment of pea varieties in a competitive varietal test under conditions of Kirov region (Volga-Vyatka economic region) on productivity of grain, green matter and hay are presented. An object under research - 21 pea varieties of different morphotype bred in Falenki breeding station. Meteorological conditions for years of research (2014-2017) differed significantly in temperature regime and the amount of precipitation: favorable conditions for pea vegetation were in 2014 and 2015, the adverse ones - in 2016 and 2017. In group of grain-hay white-flowered plants variety Falensky yubileiny was selected. It had an average yield of grain - 4.1 t/ha, green mat ter - 34.3 t/ha, hay - 4.4 t/ha that exceeded standard variety Krasnoufimsky 93 by 0.7, 9.0 and 0.8 t/ha respectively. Among grain-hay color-flowered plants the perspective line D-24746 (productivity of grain - 4.0 t/ha; green matter - 35.3 t/ha, hay - 5.5 t/ha) exceeded standard variety Ryabchik by 0.6, 5.3 and 1.3 t/ha respectively. The varieties were defined which exceeded standards by grain productivity (Vita, D-22477, E-3542, D-22596, E-630, E-626, E-460, E-3698), green matter (E-3583, E-411, D-22596), and dry matter (E-3583). All samples had strong variation in productivity of grain, green matter and hay. Varieties with high rates of productivity elements were selected. It has been established that the majority of the studied varieties belong to middle-grain type according to the 1000-grain mass. Large-grain varieties are Vita (1000-grain mass of 264 g) and Falensky usaty (1000-grain mass of 263 g); small-grain ones are E-411 (140 g) and E-246 (136 g).

Review of the southern African Moraea ciliata complex (Iridaceae: Iridoideae) including the three new taxa M. flava and M. ciliata subsp. cuprina and subsp. lutescens

The Moraea ciliata complex (Moraea subg. Acaules) from the southern African winter-rainfall zone currently includes four vegetatively similar species: a widespread M. ciliata plus three more localized species, Moraea longipes, Moraea macronyx and Moraea tricolor. Examination of herbarium collections and wild populations of M. ciliata throughout its range indicates that the recognition of one new species and two subspecies better reflects the ecological and morphological patterns in the species. The new species Moraea flava from the western Karoo with pale yellow flowers and smooth leaves with thickened and crisped margins is sometimes sympatric with typical blue–flowered M. ciliata but blooms earlier in the season. M. ciliata subsp. cuprina is recognized for a series of pink- to red-flowered populations from deep sands along the Atlantic coast of Western Cape often with two inflorescences per plant and unusually long capsules. M. ciliata subsp. lutescens from stony sandstone-derived soils, mostly of montane habitats in Western Cape between Worcester and the Gifberg, differs consistently from blue- or white-flowered subsp. ciliata in its slightly smaller yellow flowers, narrower, usually hairless leaves, and short stamens with the filaments united for up to half their length. Unusual populations of small, white-flowered plants flowering in May and June from west and south of Swellendam are provisionally included in subsp. ciliata. These taxonomic changes render subsp. ciliata morphologically more homogeneous but still with a wide geographic range extending from the Cape Peninsula north to Springbok in Northern Cape and east though the western Karoo and Upper Karoo to near Lady Grey in Eastern Cape.

Новая разновидность Corydalis sibirica (L. fil.) Pers. (Fumariaceae) из Якутии

Many Corydalis DC. species are a nutritive base for worms and butterflies from genus Parnassius Latr. The trip to Yakutia in June — July 2015 aimed to discover relationships between these plants and insects. Some authors distinguish C. sibiriсa (L. fil.) Pers. as a forage plant for swallowtail butterfly Parnassius tenedius Eversmann and consider sporadic expansion of the butterfly depending on distribution of C. sibirica (Gluschenko, 1996; Korshunov, 2002). The distribution range of C. sibirica covers an area from the Arctic Siberia to Mongolia and Northern China (Heilongijang, Jilin, Inner Mongolia); isolated localities are known on the outskirts of eastern Ural Mts., along the Kakva River; as well as in Chukotka, Kamchatka (rarely), the Magadan Region and Khabarovsk Territory. Along its whole range, С. sibiriсa occurs on more or less disturbed habitats. Plants with white flowers and intensely dove-coloured leaves were found nearby Kubume village in Oymyakon District of the Republic of Yakutia, side by side with common yellow-flowered ones. Laid eggs of the swallowtail butterfly were noticed only on С. sibiriсa with yellow flowers and did not present on white-flowered plants. Probably, the changes of flower colour will prevent these plants from being a fodder plant for Parnassius tenedius. The plants with white flowers are described as a new variety.

Inheritance and reproductive consequences of floral anthocyanin deficiency in Silene dioica (Caryophyllaceae).

• Flower color is one of the most important traits for pollinator attraction. However, natural plant populations often harbor rare flower color variants resulting from mutations in biochemical pathways for floral pigment production. It is unclear how such mutations can persist because they can affect not only pollinator visitation but also plant fertility and performance.• We collected rare white-flowered (anthocyanin-deficient) and common pink-flowered morphs of Silene dioica from natural populations in Switzerland. First- and second-generation hybrids between pink and white morphs, as well as backcrosses toward white morphs were produced, and the proportion of white-flowered offspring was determined. We compared seed siring ability and seed production between morphs using hand pollination experiments. Moreover, we scored the transfer of pollen analogues (fluorescent dyes) in a 50:50 array of the two morphs.• The proportions of white-flowered plants in the offspring of our crosses were consistent with more than one recessive mutation as the cause of floral anthocyanin deficiency and further suggested a role of maternal effects for flower color. Seed siring ability and seed set did not differ significantly between pink and white morphs. Pollen transfer occurred preferentially within morphs.• Overall, our results imply that the white morph of S. dioica likely is caused by recessive mutations that do not impair reproduction. However, as this flower color polymorphism led to assortative mating in our experiment, it may represent standing genetic variation with the potential to contribute to evolutionary divergence.

Asymmetric pollen–pistil interactions contribute to maintaining floral colour polymorphism in a clonal aquatic plant (Butomus umbellatus L.)

Floral colour polymorphism occurs in many species throughout the angiosperms but the mechanisms of selection remain unclear. In this study, we studied the pollen–pistil interactions between different Butomus umbellatus plants, a clonal aquatic plant with red and white-flowered individuals. Results indicated that red-flowered plants have lower asexual and sexual reproductive output compared to white-flowered plants in monomorphic populations, even though there are no differences in flower characteristics and pollination systems. On the other hand, in polymorphic populations, sexual reproductive output in red-flowered plants increases while asexual reproductive output decreases considerably. However, this remains unaffected in white-flowered plants. Artificial pollination treatments revealed asymmetric pollen–pistil interactions between red and white-flowered individuals. Inter-morph crosses increase seed production only when the red-flowered plant is maternal. Moreover, pollen grains of white-flowered plants significantly enhance not only female fitness by way of greater seed yields, but also male fitness by promoting fertility of pollen on stigma within a flower. Such special pollen–pistil interactions might form one kind of balancing selection and actively maintain both genotypes of the two morphs. These findings may enrich our understanding of mechanisms of maintaining plant reproductive polymorphism.

Florivores prefer white versus pink petal color morphs in wild radish, Raphanus sativus

Many hypotheses suggest that pollinators act to maintain or change floral color morph frequencies in nature, although pollinator preferences do not always match color morph frequencies in the field. Therefore, non-pollinating agents may also be responsible for color morph frequencies. To test this hypothesis, we examined whether Raphanus sativus plants with white flowers received different amounts of florivory than plants with pink flowers, and whether florivores preferred one floral color over the other. We found that white-flowered plants received significantly more floral damage than pink-flowered plants in eight populations over 4 years in northern California. Both generalists and specialists on Brassicaceae preferred white petals in choice and short-term no choice tests. In performance tests, generalists gained more weight on white versus pink petals whereas specialists gained similar amounts of weight on pink and white morphs. Because our results suggest that florivores prefer and perform better on white versus pink flowers, these insects may have the opportunity to affect the frequency of color morphs in the field.

Development of SCAR markers linked to zt-2, one of the genes controlling absence of tannins in faba bean

Faba beans (Vicia faba L.) have a great potential as a protein-rich fodder crop, but anti-nutritional factors such as condensed tannins reduce the biological value of their protein. Tannins can be removed from seeds by any of the two complementary genes, zt-1 and zt-2, which also determine white-flowered plants. The less common gene, zt-2, is also associated with increased protein levels and energy values and reduced fibre content of the seeds. To identify a cost-effective marker linked to zt-2, we analysed a segregating F2 population derived from the cross between the coloured flower and high tannin content genotype Vf6 and a zt-2 line. By using Bulked Segregant Analysis (BSA), five RAPD markers linked in coupling and repulsion phase to zt-2 were identified and their conversion into Sequence Characterised Amplified Regions (SCARs) was attempted. Amplification of the SCARS was more consistent, although the initial polymorphism was lost. Restriction digestion of SCAR SCAD16589 with AluI (SCAD16-A), Bsp120I (SCAD16-B) and HinfI (SCAD16-H) revealed clear differences due to the amplification of different loci. The consensus sequence of these CAPs (Cleavage Amplification Polymorphisms) markers allowed discrimination of three bands from which two new forward SCAR primers were developed based on specific sequences from zero tannin and high tannin content genotypes. To improve the efficiency of the marker screening, a multiplex PCR was developed that allowed the simultaneous amplification of the SCAR with the same advantages as a codominant marker. Marker validation was carried out with a new F2 population segregating for flower colour and tannin content, underscoring the potential of these markers in breeding selection to introgress the zt-2 gene for the development of new tannin free faba bean cultivars.

Flower colour is associated with susceptibility to disease in the legumeSwainsona formosa

The hypothesis that plants of the ornamental Australian native legume Swainsona formosa (Sturt’s desert pea) with reduced flower pigmentation are more susceptible to soilborne diseases was investigated using red, pink and white-flowered lines challenged with Phytophthora cinnamomi. Inoculations of roots, hypocotyls and detached stems showed that the red line was completely resistant, the white line highly susceptible, and the pink line intermediate in reaction. Similar results were obtained for root and detached stem assays using Pythium irregulare and Fusarium solani isolated from diseased white-flowered plants, but all lines were equally susceptible to Botrytis cinerea in detached stem assays. Crosses between the red and white lines showed that white flowers and susceptibility to P. cinnamomi were each determined by recessive alleles at single loci, which segregated together.

Natural outcrossing rate in Vernonia galamensis

Abstract Vernonia galamensis is a potential new industrial crop growing wild in Ethiopia. The seed oil is rich in vernolic acid, an epoxy fatty acid, which is of interest for oleochemical uses. Basic information on the reproductive system of Vernonia is still very limited. The amount of natural outcrossing was estimated at two locations in Ethiopia (Alemaya and Babile) using flower colour as a marker. Single plants with white flowers, which is a monogenic recessive trait, were planted in plots with normal pink flowers and the outcrossing rate was estimated from the frequency of pink‐flowered plants in the progeny of the white‐flowered plants. Estimates of the natural outcrossing rate ranged between individual plants from 3.5 to 16% at Alemaya and 2.5 to 12% at Babile. Vernonia galamensis can be classified as a mainly self‐pollinated species.