Morphological variation, phenotypic plasticity and fluctuating asymmetry of floral organ shapes in Iris pumila L.

Analize unutar - i među - individualnihih razlika morfoloških struktura omogućuju otkrivanje obrazaca fenotipskog variranja, kao i ekološko - evolucionih mehanizama koji dovode do njihove divergencije. U ovoj disertaciji utvrđene su komponente fenotipske varijanse oblika funkcionalno različitih cvetnih organa kod entomofilne biljne vrste Iris pumila L., polimorfne u odnosu na boju cveta. Eksperimenti su vršeni na biljkama gajenim u eksperimentalnoj bašti, poreklom iz recipročnih ukrštanja 24 klonalna genotipa. Metodama geometrijske morfometrije utvrđeni su obrasci variranja oblika tri bilateralno simetrična organa: fola, standarda i grane tučka. Kod sva tri organa udeo simetrične komponente u ukupnom variranju oblika bio je najveći, dok je fluktuirajuća asimetrija (FA) dominirala u asimetričnoj komponenti. Iako se smatra da je primarni uzrok FA nestabilnost razvića, naša istraživanja su pokazala da fenotipska plastičnost može takođe da proizvede FA. Naime, replike cvetnih organa sa različitom orijentacijom prema suncu imale su različite vrednosti asimetričnih komponenti varijanse oblika, kao rezultat plastičnosti u odnosu na mikrosredinsku heterogenost ambijentalne svetlosti. Da veličina, oblik i boja cveta predstavljaju vizuelne signale za privlačenje potencijalnih oprašivača potvrdila su poređenja veličine cvetnih organa oprašenih i neoprašenih biljaka. Oprašeni cvetovi su, po pravilu, imali veće organe od neoprašenih, sa izuzetkom grane tučka. Regresione analize su pokazale da je veličina fola bila pod delovanjem pozitivne, a grane tučka negativne direkcione selekcije. Suprotno tome, oblik cvetnih organa se razlikovao u zavisnosti od boje, što ukazuje da je preferencija oprašivača prema specifičnim kombinacijama vizuelnih signala bila važan mehanizam morfološke divergencije reproduktivnih organa I. pumila.Analyzes of intra - and inter - individual differences of morphological structures allow the detection of patterns of phenotypic variation, as well as ecological evolutionary mechanisms leading to their divergence. In this dissertation, components of the phenotypic variation of the shape of functionally distinctive flower organs were determined in the entomophilous plant, specific for striking flower color polymorphism, Iris pumila L. Experiments were carried out on plants grown in experimental garden, originating from reciprocal crossing of 24 clonal genotypes. Using the methods of geometric morphometrics patterns of variation of the shape of three bilaterally symmetrical organs (falls, standards and style branches) have been revealed. In all three floral organs, the proportion of the symmetric component in the overall shape variation was the highest, while the fluctuating asymmetry (FA) was dominated in asymmetric component. Although it is thought that primary cause of FA is developmental instability, our research has shown that phenotypic plasticity can also produce FA. Namely, replicas of flower organs with different orientations towards the sun had different values of asymmetric components of variance of the shape, as an outcome of plasticity in relation to the microenvironmental heterogeneity of ambient light. In this dissertation it is confirmed that size, shape and color of flowers are visual attractants for pollinators. Pairwase comparisons in size between pollinated and unpollinated flowers revealed that pollinated falls and standards are bigger related to their unpollinated pairs. Regression analyzes have shown that the size of the falls was under positive selection, while size of style branches was under negative direct selection. In contrast, the shape of the flower organs differed depending on their color, indicating that the pollinator's preference for specific combinations of visual signals was an important mechanism of morphological divergence of the reproductive organs of I. pumila

Morphological variation, phenotypic plasticity and fluctuating asymmetry of floral organ shapes in Iris pumila L.

Analize unutar - i među - individualnihih razlika morfoloških struktura omogućuju otkrivanje obrazaca fenotipskog variranja, kao i ekološko - evolucionih mehanizama koji dovode do njihove divergencije. U ovoj disertaciji utvrđene su komponente fenotipske varijanse oblika funkcionalno različitih cvetnih organa kod entomofilne biljne vrste Iris pumila L., polimorfne u odnosu na boju cveta. Eksperimenti su vršeni na biljkama gajenim u eksperimentalnoj bašti, poreklom iz recipročnih ukrštanja 24 klonalna genotipa. Metodama geometrijske morfometrije utvrđeni su obrasci variranja oblika tri bilateralno simetrična organa: fola, standarda i grane tučka. Kod sva tri organa udeo simetrične komponente u ukupnom variranju oblika bio je najveći, dok je fluktuirajuća asimetrija (FA) dominirala u asimetričnoj komponenti. Iako se smatra da je primarni uzrok FA nestabilnost razvića, naša istraživanja su pokazala da fenotipska plastičnost može takođe da proizvede FA. Naime, replike cvetnih organa sa različitom orijentacijom prema suncu imale su različite vrednosti asimetričnih komponenti varijanse oblika, kao rezultat plastičnosti u odnosu na mikrosredinsku heterogenost ambijentalne svetlosti. Da veličina, oblik i boja cveta predstavljaju vizuelne signale za privlačenje potencijalnih oprašivača potvrdila su poređenja veličine cvetnih organa oprašenih i neoprašenih biljaka. Oprašeni cvetovi su, po pravilu, imali veće organe od neoprašenih, sa izuzetkom grane tučka. Regresione analize su pokazale da je veličina fola bila pod delovanjem pozitivne, a grane tučka negativne direkcione selekcije. Suprotno tome, oblik cvetnih organa se razlikovao u zavisnosti od boje, što ukazuje da je preferencija oprašivača prema specifičnim kombinacijama vizuelnih signala bila važan mehanizam morfološke divergencije reproduktivnih organa I. pumila.Analyzes of intra - and inter - individual differences of morphological structures allow the detection of patterns of phenotypic variation, as well as ecological evolutionary mechanisms leading to their divergence. In this dissertation, components of the phenotypic variation of the shape of functionally distinctive flower organs were determined in the entomophilous plant, specific for striking flower color polymorphism, Iris pumila L. Experiments were carried out on plants grown in experimental garden, originating from reciprocal crossing of 24 clonal genotypes. Using the methods of geometric morphometrics patterns of variation of the shape of three bilaterally symmetrical organs (falls, standards and style branches) have been revealed. In all three floral organs, the proportion of the symmetric component in the overall shape variation was the highest, while the fluctuating asymmetry (FA) was dominated in asymmetric component. Although it is thought that primary cause of FA is developmental instability, our research has shown that phenotypic plasticity can also produce FA. Namely, replicas of flower organs with different orientations towards the sun had different values of asymmetric components of variance of the shape, as an outcome of plasticity in relation to the microenvironmental heterogeneity of ambient light. In this dissertation it is confirmed that size, shape and color of flowers are visual attractants for pollinators. Pairwase comparisons in size between pollinated and unpollinated flowers revealed that pollinated falls and standards are bigger related to their unpollinated pairs. Regression analyzes have shown that the size of the falls was under positive selection, while size of style branches was under negative direct selection. In contrast, the shape of the flower organs differed depending on their color, indicating that the pollinator's preference for specific combinations of visual signals was an important mechanism of morphological divergence of the reproductive organs of I. pumila

Phenotypic plasticity in response to environmental heterogeneity contributes to fluctuating asymmetry in plants: first empirical evidence

Fluctuating asymmetry (FA) is widely used to quantify developmental instability (DI) in ecological and evolutionary studies. It has long been recognized that FA may not exclusively originate from DI for sessile organisms such as plants, because phenotypic plasticity in response to heterogeneities in the environment might also produce FA. This study provides the first empirical evidence for this hypothesis. We reasoned that solar irradiance, which is greater on the southern side than on the northern side of plants growing in the temperate zone of the northern hemisphere, would cause systematic morphological differences and asymmetry associated with the orientation of plant parts. We used geometric morphometrics to characterize the size and shape of flower parts in Iris pumila grown in a common garden. The size of floral organs was not significantly affected by orientation. Shape and particularly its asymmetric component differed significantly according to orientation for three different floral parts. Orientation accounted for 10.4% of the total shape asymmetry within flowers in the falls, for 11.4% in the standards, and for 2.2% in the style branches. This indicates that phenotypic plasticity in response to a directed environmental factor, most likely solar irradiance, contributes to FA of flowers under natural conditions. That FA partly results from phenotypic plasticity and not just from DI needs to be considered by studies of FA in plants and other sessile organisms

Predicting ecological responses to global warming in Iris pumila: an open-topped chamber experiment

To predict short-term plant responses to global warming, an open-topped-chamber experiment was conducted in two sun-exposed natural populations of Iris pumila during a growing season. In each population, one half of all randomly selected clonal plants were experimentally warmed using a clear-sided, open-topped chamber (OTC), while the other half experienced the ambient temperature conditions. The air temperature within the OTCs was approx.1-2 ºC higher than that outside of the OTCs in general. In spring and summer of 2018, phenotypic values of the three functional leaf traits: specific leaf area (SLA), leaf dry mass content (LDMC), and leaf water content (LWC) were recorded on the ramets from each clone growing inside and outside of the OTC. The phenotypic expressions of all analyzed traits changed significantly with temperature in both populations, but in an opposite direction. While SLA and LWC tended to be greater in the ramets developing within the OTCs relative to those growing outside of them, their LDMC values reversed, being higher inside than outside of the OTCs. The analyzed traits varied seasonally as well. Regardless of the location within a clone, the values of SLA and LWC were greater in spring then in summer. Conversely, LDMC reached its maximum in the warmer season. Our results clearly suggest that I. pumila plants have the capacity to cope with increasing temperatures by plastic responses of leaf functional traits. This finding is of crucial importance to forecast the fate of Iris populations under global warming - that is, whether they will adopt or disappear.17th Congress of the European Society for Evolutionary Biology; 2019 Aug 19-24; Turku, Finland. S36e.P12

Morphological variation, phenotypic plasticity and fluctuating asymmetry of floral organ shapes in Iris pumila L.

Analize unutar - i među - individualnihih razlika morfoloških struktura omogućuju otkrivanje obrazaca fenotipskog variranja, kao i ekološko - evolucionih mehanizama koji dovode do njihove divergencije. U ovoj disertaciji utvrđene su komponente fenotipske varijanse oblika funkcionalno različitih cvetnih organa kod entomofilne biljne vrste Iris pumila L., polimorfne u odnosu na boju cveta. Eksperimenti su vršeni na biljkama gajenim u eksperimentalnoj bašti, poreklom iz recipročnih ukrštanja 24 klonalna genotipa. Metodama geometrijske morfometrije utvrđeni su obrasci variranja oblika tri bilateralno simetrična organa: fola, standarda i grane tučka. Kod sva tri organa udeo simetrične komponente u ukupnom variranju oblika bio je najveći, dok je fluktuirajuća asimetrija (FA) dominirala u asimetričnoj komponenti. Iako se smatra da je primarni uzrok FA nestabilnost razvića, naša istraživanja su pokazala da fenotipska plastičnost može takođe da proizvede FA. Naime, replike cvetnih organa sa različitom orijentacijom prema suncu imale su različite vrednosti asimetričnih komponenti varijanse oblika, kao rezultat plastičnosti u odnosu na mikrosredinsku heterogenost ambijentalne svetlosti. Da veličina, oblik i boja cveta predstavljaju vizuelne signale za privlačenje potencijalnih oprašivača potvrdila su poređenja veličine cvetnih organa oprašenih i neoprašenih biljaka. Oprašeni cvetovi su, po pravilu, imali veće organe od neoprašenih, sa izuzetkom grane tučka. Regresione analize su pokazale da je veličina fola bila pod delovanjem pozitivne, a grane tučka negativne direkcione selekcije. Suprotno tome, oblik cvetnih organa se razlikovao u zavisnosti od boje, što ukazuje da je preferencija oprašivača prema specifičnim kombinacijama vizuelnih signala bila važan mehanizam morfološke divergencije reproduktivnih organa I. pumila.Analyzes of intra - and inter - individual differences of morphological structures allow the detection of patterns of phenotypic variation, as well as ecological evolutionary mechanisms leading to their divergence. In this dissertation, components of the phenotypic variation of the shape of functionally distinctive flower organs were determined in the entomophilous plant, specific for striking flower color polymorphism, Iris pumila L. Experiments were carried out on plants grown in experimental garden, originating from reciprocal crossing of 24 clonal genotypes. Using the methods of geometric morphometrics patterns of variation of the shape of three bilaterally symmetrical organs (falls, standards and style branches) have been revealed. In all three floral organs, the proportion of the symmetric component in the overall shape variation was the highest, while the fluctuating asymmetry (FA) was dominated in asymmetric component. Although it is thought that primary cause of FA is developmental instability, our research has shown that phenotypic plasticity can also produce FA. Namely, replicas of flower organs with different orientations towards the sun had different values of asymmetric components of variance of the shape, as an outcome of plasticity in relation to the microenvironmental heterogeneity of ambient light. In this dissertation it is confirmed that size, shape and color of flowers are visual attractants for pollinators. Pairwase comparisons in size between pollinated and unpollinated flowers revealed that pollinated falls and standards are bigger related to their unpollinated pairs. Regression analyzes have shown that the size of the falls was under positive selection, while size of style branches was under negative direct selection. In contrast, the shape of the flower organs differed depending on their color, indicating that the pollinator's MORPHOLOGICAL VARIATION, PHENOTYPIC PLASTICITY AND FLUCTUATING ASYMMETRY OF FLORAL ORGAN SHAPES IN Iris pumila L. Abstract preference for specific combinations of visual signals was an important mechanism of morphological divergence of the reproductive organs of I. pumila

Morphological variation, phenotypic plasticity and fluctuating asymmetry of floral organ shapes in Iris pumila L.

Analize unutar - i među - individualnihih razlika morfoloških struktura omogućuju otkrivanje obrazaca fenotipskog variranja, kao i ekološko - evolucionih mehanizama koji dovode do njihove divergencije. U ovoj disertaciji utvrđene su komponente fenotipske varijanse oblika funkcionalno različitih cvetnih organa kod entomofilne biljne vrste Iris pumila L., polimorfne u odnosu na boju cveta. Eksperimenti su vršeni na biljkama gajenim u eksperimentalnoj bašti, poreklom iz recipročnih ukrštanja 24 klonalna genotipa. Metodama geometrijske morfometrije utvrđeni su obrasci variranja oblika tri bilateralno simetrična organa: fola, standarda i grane tučka. Kod sva tri organa udeo simetrične komponente u ukupnom variranju oblika bio je najveći, dok je fluktuirajuća asimetrija (FA) dominirala u asimetričnoj komponenti. Iako se smatra da je primarni uzrok FA nestabilnost razvića, naša istraživanja su pokazala da fenotipska plastičnost može takođe da proizvede FA. Naime, replike cvetnih organa sa različitom orijentacijom prema suncu imale su različite vrednosti asimetričnih komponenti varijanse oblika, kao rezultat plastičnosti u odnosu na mikrosredinsku heterogenost ambijentalne svetlosti. Da veličina, oblik i boja cveta predstavljaju vizuelne signale za privlačenje potencijalnih oprašivača potvrdila su poređenja veličine cvetnih organa oprašenih i neoprašenih biljaka. Oprašeni cvetovi su, po pravilu, imali veće organe od neoprašenih, sa izuzetkom grane tučka. Regresione analize su pokazale da je veličina fola bila pod delovanjem pozitivne, a grane tučka negativne direkcione selekcije. Suprotno tome, oblik cvetnih organa se razlikovao u zavisnosti od boje, što ukazuje da je preferencija oprašivača prema specifičnim kombinacijama vizuelnih signala bila važan mehanizam morfološke divergencije reproduktivnih organa I. pumila.Analyzes of intra - and inter - individual differences of morphological structures allow the detection of patterns of phenotypic variation, as well as ecological evolutionary mechanisms leading to their divergence. In this dissertation, components of the phenotypic variation of the shape of functionally distinctive flower organs were determined in the entomophilous plant, specific for striking flower color polymorphism, Iris pumila L. Experiments were carried out on plants grown in experimental garden, originating from reciprocal crossing of 24 clonal genotypes. Using the methods of geometric morphometrics patterns of variation of the shape of three bilaterally symmetrical organs (falls, standards and style branches) have been revealed. In all three floral organs, the proportion of the symmetric component in the overall shape variation was the highest, while the fluctuating asymmetry (FA) was dominated in asymmetric component. Although it is thought that primary cause of FA is developmental instability, our research has shown that phenotypic plasticity can also produce FA. Namely, replicas of flower organs with different orientations towards the sun had different values of asymmetric components of variance of the shape, as an outcome of plasticity in relation to the microenvironmental heterogeneity of ambient light. In this dissertation it is confirmed that size, shape and color of flowers are visual attractants for pollinators. Pairwase comparisons in size between pollinated and unpollinated flowers revealed that pollinated falls and standards are bigger related to their unpollinated pairs. Regression analyzes have shown that the size of the falls was under positive selection, while size of style branches was under negative direct selection. In contrast, the shape of the flower organs differed depending on their color, indicating that the pollinator's MORPHOLOGICAL VARIATION, PHENOTYPIC PLASTICITY AND FLUCTUATING ASYMMETRY OF FLORAL ORGAN SHAPES IN Iris pumila L. Abstract preference for specific combinations of visual signals was an important mechanism of morphological divergence of the reproductive organs of I. pumila

Geological Substrate Effects on <i>Teucrium montanum</i> L. (Lamiaceae) Morphological Traits: Geometric Morphometrics Approach

The shape–environment relationship in plants refers to the ways in which the physical characteristics and structures of plants are influenced by their environment. Plants have evolved a remarkable ability to adapt to their specific habitats, and their shape and form play a crucial role in determining their survival and reproductive success. This study aimed to examine differences in size and shape between morphological traits in mountain germander (Teucrium montanum L.) from different geological substrates (calcareous and serpentinite). For this study, 400 individuals of T. montanum from 20 populations (ten populations from the serpentinite and ten from the calcareous substrate) were selected. Using the geometric morphometrics approach, it was shown that the degree of phenotypic variation in the size and shape of the corolla, leaf, and stem of T. montanum depends on the type of substrate. The main differences between the populations are the narrower part of the lower lip of the corolla, the narrower leaf, and the wider central part of the vascular system stem from serpentinite populations. The results of this study will contribute to a better understanding of the morphological variability of T. montanum in relation to edaphic conditions. In addition, the results confirm that certain morphological differences play an important role in the adaptive response in relation to substrate composition, especially for substrates with increased metal content, such as serpentinite. The shape–environment relationship in plants could define diversity and complexity in plant life, and underscores the importance of shape as a key factor in their survival and success in different habitats

Phenotypic Selection on Flower Traits in Food-Deceptive Plant <i>Iris pumila</i> L.: The Role of Pollinators

To gain insight into the evolution of flower traits in the generalized food-deceptive plant Iris pumila, we assessed the color, size, shape, and fluctuating asymmetry (FA) of three functionally distinct floral organs—outer perianths (‘falls’), inner perianths (‘standards’), and style branches—and estimated pollinator-mediated selection on these traits. We evaluated the perianth color as the achromatic brightness of the fall, measured the flower stem height, and analyzed the floral organ size, shape, and FA using geometric morphometrics. Pollinated flowers had significantly higher brightness, longer flower stems, and larger floral organs compared to non-pollinated flowers. The shape and FA of the floral organs did not differ, except for the fall FA, where higher values were found for falls of pollinated flowers. Pollinator-mediated selection was confirmed for flower stem height and for subtle changes in the shape of the fall and style branch—organs that form the pollination tunnel. This study provides evidence that, although all analyzed flower traits play significant roles in pollinator attraction, flower stem height and pollination tunnel shape evolved under the pollinator-mediated selection, whereas achromatic brightness, size, and symmetry of floral organs did not directly affect pollination success

Data from: Phenotypic plasticity in response to environmental heterogeneity contributes to fluctuating asymmetry in plants: first empirical evidence

Fluctuating asymmetry (FA) is widely used to quantify developmental instability (DI) in ecological and evolutionary studies. It has long been recognized that FA may not exclusively originate from DI for sessile organisms such as plants, because phenotypic plasticity in response to heterogeneities in the environment might also produce FA. This study provides the first empirical evidence for this hypothesis. We reasoned that solar irradiation, which is greater on the southern side than on the northern side of plants growing in the temperate zone of the northern hemisphere, would cause systematic morphological differences and asymmetry associated with the orientation of plant parts. We used geometric morphometrics to characterize the size and shape of flower parts in Iris pumila grown in a common garden. The size of floral organs was not significantly affected by orientation. Shape and particularly its asymmetric component differed significantly according to orientation for three different floral parts. Orientation accounted for 10.4% of the total shape asymmetry within flowers in the falls, for 11.4% in the standards, and for 2.2% in the style branches. This indicates that phenotypic plasticity in response to a directed environmental factor, most likely solar irradiation, contributes to FA of flowers under natural conditions. That FA partly results from phenotypic plasticity and not just from DI needs to be considered by studies of FA in plants and other sessile organisms

Directional asymmetry and direction-giving factors: lessons from flowers with complex symmetry

Directional asymmetry is a systematic difference between the left and right sides for structures with bilateral symmetry or a systematic differentiation among repeated parts for complex symmetry. This study explores factors that produce directional asymmetry in the flower of Iris pumila, a structure with complex symmetry that makes it possible to investigate multiple such factors simultaneously. The shapes and sizes of three types of floral organs, the falls, standards, and style branches, were quantified using the methods of geometric morphometrics. For each flower, this study recorded the compass orientations of floral organs as well as their anatomical orientations relative to the two spathes subtending each flower. To characterize directional asymmetry at the whole‐flower level, differences in the average sizes and shapes according to compass orientation and relative orientation were computed, and the left–right asymmetry was also evaluated for each individual organ. No size or shape differences within flowers were found in relation to anatomical position; this may relate to the terminal position of flowers in Iris pumila, suggesting that there may be no adaxial–abaxial polarity, which is very prominent in many other taxa. There was clear directional asymmetry of shape in relation to compass orientation, presumably driven by a consistent environmental gradient such as solar irradiance. There was also clear directional asymmetry between left and right halves of every floral organ, most likely related to the arrangement of organs in the bud. These findings indicate that different factors are acting to produce directional asymmetry at different levels. In conventional analyses not recording flower orientations, these effects would be impossible to disentangle from each other and would probably be included as part of fluctuating asymmetry