Discovery of Gynoecium Color Polymorphism in an Aquatic Plant

Flower color polymorphism exhibited by natural populations provides an opportunity for understanding the evolutionary mechanisms contributing to the diversity of floral morphology. However, little is known about the color polymorphism of female organs in flowering plants. Here we report gynoecium color polymorphism in Butornus urnbellatus （Butomaceae）, an emergent, aquatic monocot. Populations from Mishan, northeastern China comprised two morphs; gynoecia are either pink, as observed in other areas, or white. We measured floral traits and female fecundity in the two gynoecium color morphs in the field. There was no significant difference in plant height, pedicel length, and flower size including petal, sepal and gynoecium between the two morphs, but plants with pink gynoecia had wider inflorescence stalks, larger inner whorl anthers and produced more pollen and ovules than those with white gynoecia. Correspondingly, we found that seed production was significantly higher in the pink than in the white morph. This new finding suggested selection against white gynoecia in part because of low fecundity, consistent with the rarity of the white gynoecium morph in this species.

The functional significance of a stigma color polymorphism in Acer pictum subsp. mono (aceraceae)

Aims Exploring the characteristics and function of a flower color poly-morphism contributes to our understanding of floral evolution in angiosperms.However,little information is available on stigma color polymorphisms in flowering plants despite their important functional role in plant reproduction.Methods We studied a stigma color polymorphism at the individual level in Acer pictum subsp.mono(aka A.mono)by investigating stigma-color morph proportion and comparing stigma performance and compo-nents of female fitness(pollen adhesion,pollen germination,fruit set,seed set and fruit weight)between the two morphs(red and greenish-yellow stigma)within natural populations at Dongling mountain in the north of China.in the flowering period,we conducted hand pol-lination in natural populations and then made microscopic observa-tions using the aniline blue fluorescence method.Important Findingsindividuals in the studied populations did not change their stigma color between years,and flowers produced by a single tree were uniform in their stigma color.This strongly suggests that stigma color variation is genetically controlled.The percentage of the red stigma flowers with germinated pollen grains was significantly higher than that of the greenish-yellow stigma flowers when hand pollination was conducted in the early flowering period,but not so in the late flowering period.There was no significant difference in the percentage of flowers with pollen adhesion to the stigma between the two morphs.Fruit set of the red morph was signifi-cantly higher than that of the greenish-yellow morph.our findings suggest that the red morph may be more advantageous for pollen germination and fruit set than the greenish-yellow morph,which may provide a functional explanation for the high incidence of the red stigma morph in the studied populations.alternative explana-tions for the stigma color polymorphism are discussed to stimulate further work.

Discovery of androecium color polymorphism in Epimedium pubescens with habitat preference of anther/pollen color in the genus

Aims Interspecific and intraspecific variation in flower color in natural populations provides an opportunity for us to understand the evolu-tion and maintenance of diversity of floral traits.Compared to cor-olla color,little is known about the color polymorphism of sexual organs in flowering plants.to explore evolutionary transitions of androecium color and polymorphism within species,interspecific and intraspecific variation in androecium(anther and pollen)color in the genus Epimedium(Berberidaceae)was investigated.Methods to explore the geographical patterns of anther/pollen color variation in Epimedium species,data of 45 species were collected and their phyl-ogeny was constructed based on available DNA sequences.to investi-gate whether intraspecific variation in androecium color relates to habitat preference,three environmental factors were measured in the field popu-lation of Epimedium pubescens in northeastern Sichuan,China,which plants had green or yellow androecia.Vegetative and reproductive traits of this species were compared between the two color morphs.Important Findings Androecium(anther and pollen)color polymorphism in field populations of Epimedium pubescens is reported here where nine populations are monomorphic with a green androecium but three populations are dimorphic with individuals having either a green or a yellow androecium.Inflorescence stalk height,stalk diameter,leaf number,flower number and spur length(as well as spur and nectar volume)were not significantly different between two morphs.Compared to the yellow morph,the green morph had relatively larger leaves and anthers,but smaller sepals.the green morph produced more pollen and larger seeds,but the same number of ovules.Seed set was not significantly different between green and yellow morph.Investigations of environmental factors in the color dimorphic popu-lations of E.pubescens indicated that the green morph was more likely to occur in habitats with relatively lower light intensity.the distribution survey of 45 Epimedium species showed that species with a green androecium tended to appear at lower elevations.Comparative phylogenetic analysis showed that transitions from yellow to a green androecium or to androecial color dimorphism occurred at least seven times.this genus,characterized by anther color diversity and containing some species with anther color polymorphism,provides a model system in which to study the evolution and maintenance of colorful sexual organs in flowering plants.

Does melanin-based plumage coloration reflect health status of free-living birds in urban environments?

Background:Ecological functions and processes in urban ecosystems are governed by various human activities.City-adapted and city-exploiting animal species are expected to present certain specific behavioral and physiological traits in comparison to city-avoiders or conspecific individual frequenting less urbanized or rural environments.A trait of high importance,the plumage color polymorphism has been selected as the main study model and was correlated with different morphological and physiological parameters to highlight its importance in determining the possible health status of urban Feral Pigeons(Columba livia)in North African urban habitats.Methods:Different body morphometrics,hematological and hemoparasitic parameters were quantified on freeliving Feral Pigeons in urban environments of northern Algeria.Moreover,plumage melanin-based coloration(MBC)was measured and the data collected at the individual scale was correlated with the previous parameters using linear and non-linear modeling approaches.Results:Plumage MBC scores of the sampled Feral Pigeons ranged between 0.3%and 74.8%.Among the 12 morphological traits measured,body weight,tail length and total length were deemed to be positively correlated with MBC.Darker morphs appeared to have more hemoparasites compared to lighter pigeons.Quite the same observation goes with the immunity but with non-linear trends.The number of monocytes and granulocytes increased with the increase in MBC levels in lighter morphs,while pigeons with high MBC scores exhibited negative relationships between MBC levels and the number of white blood cells.Conclusions:Despite the existence of a number of studies demonstrating phenotypic directional selection,further studies are undoubtedly necessary to understand in detail the underlying mechanisms in species life-history strategies between differently colored individuals.Findings of this correlative study open exciting perspectives revealing that MBC can be considered a good indicator of and health status and adaptation strategies to changes in urban environments.

Temporal stability and directional change in a color cline of a marine snail from NW Spain

The evolution and maintenance of color clines is a classic topic of research in evolutionary ecology.However,studies analyzing the temporal dynamics of such clines are much less frequent,due to the difficulty of obtaining reliable data about past color distributions along environmen-tal gradients.In this article,we describe a case of decades-long temporal stability and directional change in a color cline of the marine snail Littorina saxatilis along the coastal inlet of the Ria de Vigo(NW Spain).L.saxatilis from this area shows a clear color cline with 3 distinct areas from the innermost to the more wave-exposed localities of the Ria:the inner,protected localities show an abundance of fawn-like individuals;the intermediate localities show a high diversity of colors;and the outer,wave-exposed localities show populations with a high frequency of a black and lineated morph.We compare data from the 1970s and 2022 in the same localities,showing that the cline has kept relatively stable for at least over half a century,except for some directional change and local variability in the frequency of certain morphs.Multiple regression analyses and biodiversity measures are presented to provide clues into the selective pressures that might be involved in the maintenance of this color cline.Future research avenues to properly test the explanatory power of these selective agents as well as the possible origins of the cline are discussed.

Physiological phenotypes differ among color morphs in introduced common wall lizards(Podarcis muralis)

Many species exhibit color polymorphisms which have distinct physiological and behavioral characteristics.However,the consistency of morph trait covariation patterns across species,time,and ecological contexts remains unclear.This trait covariation is especially relevant in the context of invasion biology and urban adaptation.Specifically,physiological traits pertaining to energy maintenance are crucial to fitness,given their immediate ties to individual reproduction,growth,and population establishment.We investigated the physiological traits of Podarcis muralis,a versatile color polymorphic species that thrives in urban environments(including invasive populations in Ohio,USA).We measured five physiological traits(plasma corticosterone and triglycerides,hematocrit,body condition,and field body temperature),which compose an integrated multivariate phenotype.We then tested variation among co-occurring color morphs in the context of establishment in an urban environment.We found that the traits describing physiological status and strategy shifted across the active season in a morph-dependent manner—the white and yellow morphs exhibited clearly different multivariate physiological phenotypes,characterized primarily by differences in plasma corticosterone.This suggests that morphs have different strategies in physiological regulation,the flexibility of which is crucial to urban adaptation.The white-yellow morph exhibited an intermediate phenotype,suggesting an intermediary energy maintenance strategy.Orange morphs also exhibited distinct phenotypes,but the low prevalence of this morph in our study populations precludes clear interpretation.Our work provides insight into how differences among stable polymorphisms exist across axes of the phenotype and how this variation may aid in establishment within novel environments.

Viability,behavior,and color expression in the offspring of matings between common wall lizard Podarcis muralis color morphs

Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature.Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis.Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations.Here,we examined the effect of parental morph combination on fertilization success,embryonic viability,newborn quality,antipredator,and foraging behavior,as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid Podarcis muralis,where color morphs are frequently assumed to reflect alternative phenotypic optima(e.g.,alternative reproductive strategies).Juveniles were kept in outdoor tubs for a year in order to study inter-annual growth,survival,and morph inheritance.In agreement with a previous genome-wide association analysis,morph frequencies in the year-old juveniles matched the frequencies expected if orange and yellow expressions depended on recessive homozygosity at 2 separate loci.Our findings also agree with previous literature reporting higher reproductive output of heavy females and the higher overall viability of heavy newborn lizards,but we found no evidence for the existence of alternative breeding investment strategies in female morphs,or morphcombination effects on offspring viability and behavior.We conclude that inter-morph breeding remains entirely viable and genetic incompatibilities are of little significance for the maintenance of discrete color morphs in P.muralis from the Pyrenees.

Epistatic interactions between pterin and carotenoid genes modulate intra-morph color variation in a lizard

Color polymorphisms have become a major topic in evolutionary biology and substantial efforts have been devoted to the understanding of the mechanisms responsible for originating such colorful systems.Within-morph continuous variation,on the other hand,has been neglected in most of the studies.Here,we combine spectrophotometric/visual modeling and genetic data to study the mechanisms promoting continuous variation within categorical color morphs of Podarcis muralis.Our results suggest that intra-morph variability in the pterin-based orange morph is greater compared to white and yellow morphs.We also show that continuous variation within the orange morph is partially discriminable by conspecifics.Genotyping results indicate that allelic variants at the BCO2 locus(responsible for deposition of yellow carotenoids)contribute to generate continuous variation in orange individuals.However,other intrinsic and/or extrinsic mechanisms,such as body size,might be involved,opening a new avenue for future research on the drivers of continuous variation within-morphs.