Abdominal Grey Color Variation along an Elevation Gradient in a Lizard

Color variation among populations is thought to be either due to genetic variation or phenotype plasticity.In this study,we found that an agamid lizard,Phrynocephalus theobaldi,inhabiting elevations greater than any other reptile,displayed a significantly darker spotted marking on the central ventral abdomen in higher populations than in lower populations.The grey spotted area only occurred in elevations>4200 m,and also increased with increased elevation.The ratio of the size of the dark colored area to the degree of skin luminance/reflectance was used to test whether the lizard has a larger and darker spotted area at higher elevations.This ratio was significantly positively associated with elevation rather than substrate color.The lizard did not display sexual difference in this phenotype.Temperature had a significant influence on the brightness of central abdomen,but temperature-related plasticity of this trait was much smaller than the magnitude of the difference between higher(>4200 m)and lower populations(<4200 m).Common garden experiments showed that genetic inheritance,rather than phenotype plasticity,played a dominant role in this variation.Our research addressed the darkness of a body region that is rarely analyzed because it is shielded from direct insolation.The idea that ventral color could be related to thermoregulation is shown to be worthy of further research.

Genetic differentiation in functional traits among wild cherry (Prunus avium L.) half-sib lines

Understanding intra-specific variation in leaf functional traits is one of the key requirements for the evaluation of species adaptive capacity to ongoing climate change, as well as for designing long-term breeding and conservation strategies. Hence, data of 19 functional traits describing plant physiology, antioxidant properties, anatomy and morphology were determined on 1-year-old seedlings of wild cherry (Prunus avium L.) half-sib lines. The variability within and among half-sib lines, as well as the estimation of multi-trait association, were examined using analysis of variance (ANOVA) followed by Tukey's honestly significant difference test and multivariate analyses: principal component analysis (PCA), canonical discriminant analysis (CDA) and stepwise discriminant analysis (SDA). Pearson’s correlation coefficient was used to evaluate linear correlation between the study parameters. The results of the ANOVA showed the presence of statistically significant differences (P < 0.01) among half-sib lines for all study traits. The differences within half-sib lines, observed through the contribution of the examined sources of variation to the total variance (%), had higher impact on total variation in the majority of the examined traits. Pearson’s correlation analysis and PCA showed strong relationships between gas exchange in plants and leaf size and stomatal density, as well as between leaf biomass accumulation, intercellular CO_(2) concentration and parameters related to antioxidant capacity of plants. Likewise, the results of SDA indicate that transpiration and stomatal conductance contributed to the largest extent, to the discrimination of the wild cherry half-sib lines. In addition, PCA and CDA showed separation of the wild cherry half-sib lines along the first principal component and first canonical variable with regards to humidity of their original sites. Multiple adaptive differences between the wild cherry half-sib lines indicate high potential of the species to adapt rapidly to climate change. The existence of substantial genetic variability among the wild cherry half-sib lines highlights their potential as genetic resources for reforestation purposes and breeding programmes.

Enhanced allelopathy and competitive ability of invasive plant Solidago canadensis in its introduced range

Aims Why invasive plants are more competitive in their introduced range than native range is still an unanswered question in plant invasion ecology.Here,we used the model invasive plant Solidago canaden-sis to test a hypothesis that enhanced production of allelopathic compounds results in greater competitive ability of invasive plants in the invaded range rather than in the native range.We also exam-ined the degree to which the allelopathy contributes increased com-petitive ability of S.canadensis in the invaded range.Methods We compared allelochemical production by S.canadensis growing in its native area(the USA)and invaded area(China)and also by populations that were collected from the two countries and grown together in a'common garden'greenhouse experiment.We also tested the allelopathic effects of S.canadensis collected from either the USA or China on the germination of Kummerowia striata(a native plant in China).Finally,we conducted a common garden,greenhouse experiment in which K.striata was grown in monocul-ture or with S.canadensis from the USA or China to test the effects of allopathy on plant-plant competition with suitable controls such as adding activated carbon to the soil to absorb the allelochemicals and thereby eliminating any corresponding allopathic effects.Important findings Allelochemical contents(total phenolics,total flavones and total saponins)and allelopathic effects were greater in S.canadensis sampled from China than those from the USA as demonstrated in a field survey and a common garden experiment.Inhibition of K.stri-ata germination using S.canadensis extracts or previously grown in soil was greater using samples from China than from the USA.The competitive ability of S.canadensis against K.striata was also greater for plants originating from China than those from the USA.Allelopathy could explain about 46%of the difference.These find-ings demonstrated that S.canadensis has evolved to be more allelo-pathic and competitive in the introduced range and that allelopathy significantly contributes to increased competitiveness for this inva-sive species.

Evolution of herbs: key to the conundrum might be tolerance not avoidance

Aims Woody plants represent the ancestral growth form in angiosperms with herbs evolving repeatedly from them.While there are a number of hypotheses about drivers of the evolution of the herbaceous habit,the ability to avoid frost damage in winter by discarding their aboveground biomass has often been invoked as the main force in their evolution.We propose instead that any unpredictable disturbance might have been much more important than the seasonal frost,as herbs easily survive repeated disturbance.Methods We tested this hypothesis by comparing herbs and woody plants in their ability to deal with three types of simulated disturbances,more predictable winter freezing,less predictable spring freezing and herbivory.Comparison was made in an experimental common garden setup with 20 species differing in woodiness.We evaluated the effects of these disturbances on mortality and regrowth of plants.Important Findings Herbs did not have an advantage over woody plants in survival when exposed to winter freezing.In less predictable conditions of spring freezing herbs survived the treatment better than woody plants and this advantage was even larger in case of the simulated herbivory treatment.The advantage of herbs over woody plants in less predictable conditions suggests that herbaceous growth form might be an adaptation to unpredictable disturbance,which herbs are able to tolerate thanks to their ability to survive loss of aboveground biomass.Consequently,factors such as mammal herbivory or fire might have been the most likely factors in the transition from woody species to herbs.