Evolution of the Portulaca oleracea L. aggregate in Egypt on molecular and phenotypic levels revealed by morphology,inter-simple sequence repeat (ISSR) and 18S rDNA gene sequence markers

Molecular markers including inter simple sequence repeats (ISSR) and 18S rDNA gene sequence markers were combined with a detailed morphological analysis to seek characters that discriminate four taxa of Portulaca oleracea s.l. These taxa were identified as the microspecies Portulaca nitida, Portulaca oleracea, Portulaca rausii and Portulaca granulatostellulata. Morphological characters did not provide a clear distinction among the four taxa of P. oleracea s.l. It was found that mixed populations of the taxa occur in several locations and morphological similarities between the microspecies were detected. ISSR analysis indicates that gene flow among populations of different taxa was high and most of the genetic variation (61.9%) occurs within population. These results are inconsistent with the general characteristics of P. oleracea as a self- or 5% cross-pollinated species. A close relationship between P. oleracea, P. rausii and P. granulatostellulata was supported by ISSR and 18S rDNA gene sequence. The ISSR and 18s data support the specific status of P. nitida as a recently evolved taxon. We conclude that P. oleracea exists as a polymorphic species and is not divisible into microspecies based on seed surface as the primary morphological trait, and inter simple sequence repeats (ISSR) and 18S rDNA gene sequence markers. We suggest that the taxa do not merit specific rank as morphological characters and absence of a breeding barrier fail to separate the different populations when they become sympatric.     

An experimental study of geographic variation in avian growth and development

Reciprocal transplant and “common garden” experiments were done to distinguish the genetic and environmental components of geographic variation in growth, development and morphological characters of Mallard Ducks (Anas platyrhynchos) from California, USA and Manitoba, Canada. Most of the variation in growth and development could be attributed to differences in nesting phenology and local environmental conditions. Differences in morphological characters typical of birds in the two wild populations could be induced by transplanting young between localities. All differences between populations disappeared in the F1 offspring from captive breeding crosses, reared in a common environment. These results suggest that population-level variation in growth, development and morphology of Mallards in the wild is environmentally induced.     

Responses of Nutrients and Mobile Carbohydrates in Quercus variabilis Seedlings to Environmental Variations Using In Situ and Ex Situ Experiments

Forest tree species distributed across a wide range of geographical areas are subjected to differential climatic and edaphic conditions and long-term selection, leading to genotypes with morphological and physiological adaptation to the local environment. To test the ability of species to cope with changing environmental conditions, we studied the ecophysiological features of Quercus variabilis using seedlings grown in geographically widely isolated populations (Exp. I, in situ) and in a common garden (Exp. II, ex situ) using seedlings originating from those populations. We found that Q. variabilis plants grown in different locations along a south-north gradient had different levels of nutrients (N, P, K) and carbon-physiological performance (photosynthesis, non-structural carbohydrates, such as soluble sugars and starch), and that these physiological differences were not correlated with local soil properties. These geographic variations of plant physiology disappeared when plants from different locations were grown in the same environment. Our results indicate that the physiological performance of Q. variabilis plants is mainly determined by the climatic variations across latitude rather than by their soils or by genetic differentiation. The adaptive ability of Q. variabilis found in the present study suggests that this species has the potential to cope, at least to some extent, with changing environmental conditions.     

Differentiation of Diploid and Triploid Taxa within Taraxacum sect. Erythrosperma (Asteraceae) from the Pannonian Region

Six taxa of the genus Taraxacum sect. Erythrosperma were analyzed morphometrically using multivariate methods. A total of 391 specimens from Slovakia, Hungary, Czech Republic and Austria were studied. This study aimed to explore if leaf shape can be used to differentiate diploids and triploids, to verify if triploid microspecies deserve separate taxonomic status, and if the diploid plants can be divided into phenotype groups. The analysis of leaf-shape variability revealed no notable difference between diploid and triploid plants. The analysis of the triploid microspecies T. cristatum, T. danubium, T. parnassicum, T. princeps and T. proximum s.l. resulted in their differentiation into separate groups. For differentiation, the characters with a higher determination value were employed, especially the shape of a terminal leaf lobe, the position of outer bracts, the number of lateral lobes and their termination. Analyzing a very variable diploid species T. erythrospermum enabled the definition of four basic phenotypes based on leaf shape. The phenotypes differed in leaf size and shape in relation to environmental factors such as intensity of light, nutrients, moisture, or disturbance. In conclusion, to evaluate the taxonomic status of particular taxa within Taraxacum sect. Erythrosperma it is inevitable to understand the complex leaf-shape variability, being a result of both genetic variability and phenotypic plasticity.     

ENVIRONMENTAL SENSITIVITY OF SEXUAL AND APOMICTIC ANTENNARIA: DO APOMICTS HAVE GENERAL-PURPOSE GENOTYPES?

The fact that apomictic taxa typically occupy a wider range of environments than their sexual relatives has generated the hypothesis that apomicts are more likely to possess “general-purpose genotypes,” i.e., genotypes whose performance is relatively insensitive to changes in environmental conditions. This hypothesis was tested by cloning sexual and apomictic females of Antennaria parvifolia (Asteraceae) and growing each genotype in six growth-chamber environments varying in temperature and moisture levels. A joint regression analysis revealed that the survival of apomictic genotypes was significantly less sensitive to environmental conditions than that of sexual genotypes but demonstrated no differences with regard to flowering or biomass. However, the coefficient of variation in biomass across the six environments was significantly lower for apomicts than for sexuals, and the geometric mean of survival over the six environments was significantly higher for apomicts. Apomicts significantly exceeded sexuals in mean survival, mean flower-head production, and mean biomass. These results support the hypothesis that apomictic genotypes are more “general-purpose” than sexuals, and increase the difficulty of explaining the persistence of sexual reproduction in A. parvifolia.     

Ecological Plasticity of the Photosynthetic Apparatus of <Emphasis Type="Italic">Hibiscus syriacus</Emphasis> L. under Pressure of High Temperature,Insolation, and Air Pollution

This paper describes the integrated effect of high summer temperature, intensive insolation, gas pollution, and dust in the air on the pigment content and net oxygen production (apparent photosynthesis) and dark respiration rates of common hibiscus (Hibiscus syriacus L.) leaves. The study included three observation sites: Tashkent Botanical Garden (Academy of Sciences, the Republic of Uzbekistan), the public garden in the central part of the city of Tashkent, and a mountain holiday camp. The research was carried out in 2017 during the period of active vegetation. The results of experiments showed a high adaptive potential of H. syriacus L., as well as its adaptiveness to stress environmental factors of the semiarid zone, provided a sufficient level of its irrigation. The ecological plasticity of the photosynthetic apparatus of hibiscus plays a key role in species adaptation to environmental conditions. It has been revealed that the growth of the plants of the Tashkent Botanical Garden under shading conditions leads to the formation of large, wide, thin, shade leaf blades, which can be considered as the manifestation of sciomorphosis. Heliomorphosis features of hibiscus leaves were identified in mountains, where sun leaves with significantly smaller, thickened, and compacted blades are formed under high insolation. The adaptive significance of these structural leaf modifications is to strengthen photosynthetic capacity for compensating the deficiency in sunlight (in the case of sciomorphosis), and, on the contrary, to provide mutual shading for photosynthetic elements as a measure of protection against the damaging effect of redundant solar radiation (in the case of heliomorphosis). This provides carbon dioxide assimilation and organic matter production for maintaining the constant energy balance for the plant under different environmental conditions. The study of the temperature correlation of dark respiration and net oxygen production rates has shown that these processes are more resistant to temperature injuries under more extreme environmental conditions. In addition, mature H. syriacus leaves have a higher resistance than young leaves; i.e., the plant adapts to possible temperature drops in the process of its ontogenesis. Taking into account the optimal measuring conditions, the net oxygen production rate of H. syriacus during the period of active vegetation is approximately at the same level under different growing conditions (0.20 ± 0.05 μmol of O₂/(dm² s)); this is considered a norm of reaction of the net production (apparent photosynthesis) rate of H. syriacus and determines the specific features of its photosynthetic apparatus.     

EFFECTS OF MATERNAL AND PATERNAL ENVIRONMENT AND GENOTYPE ON OFFSPRING PHENOTYPE IN SOLIDAGO ALTISSIMA L.

To predict the possible evolutionary response of a plant species to a new environment, it is necessary to separate genetic from environmental sources of phenotypic variation. In a case study of the invader Solidago altissima, the influences of several kinds of parental effects and of direct inheritance and environment on offspring phenotype were separated. Fifteen genotypes were crossed in three 5 × 5 diallels excluding selfs. Clonal replicates of the parental genotypes were grown in two environments such that each diallel could be made with maternal/paternal plants from sand/sand, sand/soil, soil/sand, and soil/soil. In a first experiment (1989) offspring were raised in the experimental garden and in a second experiment (1990) in the glasshouse. Parent plants growing in sand invested less biomass in inflorescences but produced larger seeds than parent plants growing in soil. In the garden experiment, phenotypic variation among offspring was greatly influenced by environmental heterogeneity. Direct genetic variation (within diallels) was found only for leaf characters and total leaf mass. Germination probability and early seedling mass were significantly affected by phenotypic differences among maternal plants because of genotype ( genetic maternal effects ) and soil environment ( general environmental maternal effects ). Seeds from maternal plants in sand germinated better and produced bigger seedlings than seeds from maternal plants in soil. They also grew taller with time, probably because competition accentuated the initial differences. Height growth and stem mass at harvest (an integrated account of individual growth history) of offspring varied significantly among crosses within parental combinations ( specific environmental maternal effects ). In the glasshouse experiment, the influence of environmental heterogeneity and competition could be kept low. Except for early characters, the influence of direct genetic variation was large but again leaf characters (= basic module morphology) seemed to be under stricter genetic control than did size characters. Genetic maternal effects, general environmental maternal effects, and specific environmental maternal effects dominated in early characters. The maternal effects were exerted both via seed mass and directly on characters of young offspring. Persistent effects of the general paternal environment ( general environmental paternal effects ) were found for leaf length and stem and leaf mass at harvest. They were opposite in direction to the general environmental maternal effects, that is the same genotypes produced “better mothers” in sand but “better fathers” in soil. The general environmental paternal effects must have been due to differences in pollen quality, resulting from pollen selection within the male parent or leading to pre- or postzygotic selection within the female parent. The ranking of crosses according to mean offspring phenotypes was different in the two experiments, suggesting strong interaction of the observed effects with the environment. The correlation structure among characters changed less between experiments than did the pattern of variation of single characters, but under the competitive conditions in the garden plant height seemed to be more directly related to fitness than in the glasshouse. Reduced competition could also explain why maternal effects were less persistent in the glasshouse than in the garden experiment. Evolution via selection of maternal effects would be possible in the study population because these effects are in part due to genetic differences among parents.     

Phenotypic plasticity inPotamogeton (Potamogetonaceae)

Sources of the extensive morphological variation of the species and hybrids ofPotamogeton were studied, especially from the viewpoint of the stability of the morphological characters used inPotamogeton taxonomy. Transplant experiments, the cultivation of clones under different values of environmental factors, and the cultivation of different clones under uniform conditions were performed to assess the proportion of phenotypic plasticity in the total morphological variation. Samples from 184 populations of 41Potamogeton taxa were grown. The immense range of phenotypic plasticity, which is possible for a single clone, is documented in detail in 14 well-described examples. The differences among distinct populations of a single species observed in the field were mostly not maintained when grown together under the same environmental conditions. Clonal material cultivated under different values of environmental factors produced distinct phenotypes, and in a few cases a single genotype was able to demonstrate almost the entire range of morphological variation in an observed trait known for that species. Several characters by recent literature claimed to be suitable for distinguishing varieties or even species were proven to be dependent on environmental conditions and to be highly unreliable markers for the delimiation of taxa. The unsatisfactory taxonomy that results when such classification of phenotypes is adopted is illustrated by three examples from recent literature. Phenotypic plasticity was found to be the main source of morphological variation within the species ofPotamogeton, having much more influence than morphological differences caused by different genotypes.     

Alchemilla schmakovii sp. nov. from eastern Europe

A morphological study of specimens collected by the author and a critical revision of the key herbarium collections revealed a new rather peculiar taxon of Alchemilla occurring in almost every region of the Middle Volga basin, Russia. This novelity is here described as A. schmakovii and images of the principal morphological features of this species are provided. The new species is compared with related species in A. sect. Alchemilla (e.g. A. micans) and sect. Plicatae (e.g. A. breviloba) based on morphological characteristics.     

Root hydraulic conductance,gas exchange and leaf water potential in seedlings of Pistacia lentiscus L. and Quercus suber L. grown under different fertilization and light regimes

Differences in morphology, biomass allocations and physiological responses were investigated in seedlings of Mastic tree (Pistacia lentiscus L.) and Cork oak (Quercus suber L.) submitted to contrasting fertilization and light regimes during early growth. These species are two evergreen sclerophyllous Mediterranean species frequently used in Mediterranean reforestation programmes. Fertilization was the treatment that affected most of the morphological and physiological variables evaluated in P. lentiscus and Q. suber seedlings. Leaf area and specific leaf area (SLA) were affected by shading treatment in both species, showing higher values in seedlings grown under shade. P. lentiscus seedlings showed a high capacity to modify root morphological variables and root hydraulic conductance (K_R) with the fertilization treatment. In contrast, Q. suber showed low to moderate root system changes with the treatments applied, although the fertilization level affected biomass allocation (i.e., root to shoot ratio) in both species. Under high water demand, P. lentiscus seedlings with high K_R allowed transpiration (E) to increase without increasing the water potential gradient between soil and leaves. In Q. suber, high fertilization induced significant increases in photosynthesis (A), as well as a tendency to increase E with significantly lower leaf water potential (ψ_L).     

The functional divergence of biomass partitioning,carbon gain and water use in Coffea canephora in response to the water supply: Implications for breeding aimed at improving drought tolerance

Robusta coffee (Coffea canephora) is widely cultivated in regions where water availability is the major environmental constraint affecting crop production. The functional divergence associated with biomass partitioning, carbon gain and water use in response to water supply was examined in 10 one-year-old clones of robusta coffee with varying degrees of drought tolerance. The plants were grown outdoors in 24 L pots and either irrigated or subjected to a four-month water deficit. Under conditions of ample irrigation, clones with superior water use ability (i.e., a higher water potential, transpiration rate, apparent hydraulic conductance and biomass partitioning into roots and a lower wood density) displayed enhanced carbon gains. In contrast, under drought conditions, clones that postponed dehydration via more conservative water use rates showed lower relative decreases in stomatal conductance, photosynthetic rates and biomass accumulation. Isotopic signatures (δ¹³C) might be useful for identifying clones with improved performance under drought conditions. Our results suggest that combining useful morphological and physiological traits facilitates the successful assessment of coffee clonal performance in response to drought at the seedling stage. This strategy may be valuable when exploring a large number of genotypes in coffee-breeding programs because it reduces the time and resource costs that would otherwise be wasted on potentially undesirable genotypes.     

Changes in morphological plasticity of Ulva prolifera under different environmental conditions: A laboratory experiment

The large-scale green tides, consisting mainly of Ulva prolifera, have invaded the coastal zones of western Yellow Sea each year since 2008, resulting in tremendous impacts on the local environment and economy. A large number of studies have been conducted to investigate the physiological traits of U. prolifera to explain its dominance in the green tides. However, little has been reported regarding the response of U. prolifera to changing environmental factors via morphological variation. In our experiments, we found remarkable morphological acclimation of U. prolifera to various temperature (20 and 25 °C) and salinity (10, 20, and 30) conditions. U. prolifera had more, but shorter branches when they were cultured at lower temperature and salinity conditions. To investigate the significance of these morphological variations in its acclimation to changes of environmental factors, physiological and biochemical traits of U. prolifera grown under different conditions were measured. Higher temperature increased the relative growth rate while salinity did not affect it. On the other hand, higher temperature did not enhance the net photosynthetic rate whilst lower salinity did. The increased net photosynthetic rate at lower salinity conditions could be attributed to more photosynthetic pigments—chlorophyll a, chlorophyll b, and carotenoids—in thalli due to there being more branches at lower salinity conditions. Increased numbers of branches and thus an increased intensity of thalli may be helpful to protect thalli from increased osmotic pressure caused by lower salinity, but it led to more shading. In order to capture enough light when being shaded, thalli of U. prolifera synthesized more photosynthetic pigments at lower salinity levels. In addition, higher temperature increased nitrate reductase activity and soluble protein content but variations in salinity did not impose any effect on them. Our results demonstrate conclusively that U. prolifera can acclimatize in the laboratory to the changes of environmental factors (salinity and temperature) by morphology-driven physiological and biochemical variation. We suggest that the morphological plasticity of U. prolifera may be an important factor for it to outcompete other algal species in a changing ocean.     

Morphological variation in the cosmopolitan fish parasite Neobenedenia girellae (Capsalidae: Monogenea)

Intra-species morphological variation presents a considerable problem for species identification and can result in taxonomic confusion. This is particularly pertinent for species of Neobenedenia which are harmful agents in captive fish populations and have historically been identified almost entirely based on morphological characters. This study aimed to understand how the morphology of Neobenedenia girellae varies with host fish species and the environment. Standard morphological features of genetically indistinct parasites from various host fish species were measured under controlled temperatures and salinities. An initial field-based investigation found that parasite morphology significantly differed between genetically indistinct parasites infecting various host fish species. The majority of the morphological variation observed (60%) was attributed to features that assist in parasite attachment to the host (i.e. the posterior and anterior attachment organs and their accessory hooks) which are important characters in monogenean taxonomy. We then experimentally examined the effects of the interaction between host fish species and environmental factors (temperature and salinity) on the morphology of isogenic parasites derived from a single, isolated hermaphroditic N. girellae infecting barramundi, Lates calcarifer. Experimental infection of L. calcarifer and cobia, Rachycentron canadum, under controlled laboratory conditions did not confer host-mediated phenotypic plasticity in N. girellae, suggesting that measured morphological differences could be adaptive and only occur over multiple parasite generations. Subsequent experimental infection of a single host species, L. calcarifer, at various temperatures (22, 30 and 32?°C) and salinities (35 and 40‰) showed that in the cooler environments (22?°C) N. girellae body proportions were significantly smaller compared with warmer temperatures (30 and 32?°C; P?<?0.0001), whereas salinity had no effect. This is evidence that temperature can drive phenotypic plasticity in key taxonomic characters of N. girellae under certain environmental conditions.     

Estimates of Stability Parameters in Dioscorea deltoidea Wall

Estimates of stability parameters for various traits in Dioscoreadeltoidea revealed that some characters, such as, per cent diosgenincontent in tubers, stem thickness and leaf breadth were fairlystable traits. Other characters, i.e. tuber length, tuber branchingand petiole length were not stable and were greatly influencedby the environment. The stability of fifteen genotypes variesfrom character to character and six genotypes were found tobe most stable for the majority of the characters. The significantgenotypic regression on the environment indicated that it shouldnot be difficult to breed D. deltoidea strains which shouldperform fairly well under diverse environmental conditions andto recognize the most desirable properties of a genotype tobe released as a variety for wide cultivation. Diosgenin, stable traits, heritable characters, environmental effect, adaptive genotypes     

Morphological and molecular tools in identifying the Mediterranean limpets Patella caerulea, Patella aspera and Patella rustica

Allozyme electrophoresis, a partial nucleotide sequence of a mitochondrial gene for cytochrome oxidase I (COI) and discriminant analysis of shell morphometric characters were used to study the relationships among the Sicilian marine gastropods of the Patella genus. Allozyme and mtDNA markers unequivocally distinguished the species and were very useful markers in correctly classifying the different species when morphological characters overlapped each other. Several allozyme loci and many nucleotide positions were diagnostic of species. In contrast, the discriminant analysis of simple morphometric shell characters failed to adequately discriminate the species, suggesting that environmental factors influence colouration and morphological patterns in the Patella species. Our results underline the importance of a genetic approach, as compared to a morphological approach, in discriminating the Mediterranean Patella species.     

Phenotypic and genotypic variation in Iranian sour and duke cherries

Phenotypic and genotypic variation and structure of 29 sour cherry (P. cerasus) and duke cherry (P. x gondouinii) genotypes from different regions of Iran were identified using random amplified polymorphic DNA (RAPD) markers and morphological characters. Furthermore, one Prunus mahaleb genotype was used as an outgroup for molecular analysis. For morphological analysis, 23 variables were recorded to detect similarities between and among studied sour and duke cherries. Most studied characteristics were showing a high degree of variability. Principal component analysis showed that the first three components explained a total of 73.87 % of the whole phenotypic variability. Based on the morphological cluster analysis, studied sour and duke cherry genotypes were placed into three main clusters. The first main cluster included 16 sour cherry genotypes. The second main cluster contained all duke cherry genotypes and eight sour cherry genotypes, while, only one sour cherry genotype was placed in third main cluster. For RAPD analysis, 17 primers generated a total of 233 discernible and reproducible bands across genotypes analyzed, out of which 214 (91.51 %) were polymorphic with varied band size from 300 to 3000 bp. According to the similarity matrix, the lowest similarity was obtained between P. mahaleb, as an outgroup, and sour cherry. Dendrogram based on molecular data separated genotypes according to their species and geographic origin. Low correlation was observed between the similarity matrices obtained based on morphological and RAPD data. The information obtained here could be valuable for devising strategies for conservation of Iranian sour and duke cherries.     

Plagiothcium laetum in Britain

Abstract

Variations in (1) banding patterns of peroxidase, acid phosphatase and esterase isozymes and (2) morphological characters, of two British and two Finnish populations of Sphagnum recurvum var. mucronatum are described. No links were found between the presence of specific isozyme bands and individual morphological characters, nor were the individual populations typified by particular bands. The results do present some evidence for the linking of certain morphological characters with environmental conditions and suggest that there may be a relationship between the complexity of banding patterns and the stability of site conditions.     

New species ofAlchemilla ser.Hirsutae

The author describes four new apomict species ofAlchemilla L. ser.Hirsutae H. Lindb. They appear to be endemic in the Western Carpathians, growing there on some few mountain ranges, mostly in synanthropic habitats. Their known distribution areas seem to be ± separate. Two numerical indices called the epicalyx index and the hypanthium index respectively are defined to characterise the proportion of anAlchemilla flower. Ranges of both indices are shown for each of the new species.     

Host environment and local genetic adaptation determine phenotype in parasitic Rhinanthus angustifolius

Plants have a remarkable capacity to adapt to local environmental conditions, which can result in ecotypic differentiation. Patterns of differentiation can, however, also be influenced by the extensive phenotypic plasticity exhibited by many plant species. In this study, we evaluated the distinctness of two putative ecotypes of the parasitic herb Rhinanthus angustifolius. We compared population means of characters commonly used to distinguish between the putative ecotypes after growing individuals of R. angustifolius with a variety of host species in a common garden. Resulting data were also pooled over environments to study how phenotypic plasticity affects the distinctness of ecotypes and individual populations. Except for node number, most of the characters were plastic. The pattern of differentiation was consistent with the existence of two, or possibly three, habitat‐related groups of populations; however, we observed considerable overlap in flowering time and morphological characters after pooling data across host environments. The results show that the complex phenological and morphological variation in R. angustifolius is caused by a combination of genetically determined ecotypic differentiation and plastic responses to the host environment and other factors. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180 , 89–103.     

Conditions in Home and Transplant Soils Have Differential Effects on the Performance of Diploid and Allotetraploid Anthericum Species

Due to increased levels of heterozygosity, polyploids are expected to have a greater ability to adapt to different environments than their diploid ancestors. While this theoretical pattern has been suggested repeatedly, studies comparing adaptability to changing conditions in diploids and polyploids are rare. The aim of the study was to determine the importance of environmental conditions of origin as well as target conditions on performance of two Anthericum species, allotetraploid A. liliago and diploid A. ramosum and to explore whether the two species differ in the ability to adapt to these environmental conditions. Specifically, we performed a common garden experiment using soil from 6 localities within the species’ natural range, and we simulated the forest and open environments in which they might occur. We compared the performance of diploid A. ramosum and allotetraploid A. liliago originating from different locations in the different soils. The performance of the two species was not affected by simulated shading but differed strongly between the different target soils. Growth of the tetraploids was not affected by the origin of the plants. In contrast, diploids from the most nutrient poor soil performed best in the richest soil, indicating that diploids from deprived environments have an increased ability to acquire nutrients when available. They are thus able to profit from transfer to novel nutrient rich environments. Therefore, the results of the study did not support the general expectation that the polyploids should have a greater ability than the diploids to adapt to a wide range of conditions. In contrast, the results are in line with the observation that diploids occupy a wider range of environments than the allotetraploids in our system.