Stability and adaptability of 25 bread wheat (Triticum aestivum L.) cultivars were evaluated for genotype × environment interaction (G × E) and yield stability across two environments over 2 years (2014 and 2015).
Materials and methods
Five improved varieties (Haidra, Salammbô, Tahent, Utique, and Vagua) released in Tunisia and 20 introduced genotypes (V1–V20) have been tested under two contrasted environments during 2 years characterized by different precipitations in the northwest of Tunisia. Several statistical approaches were conducted to evaluate yield stability: (a) regression coefficient (bi), (b) deviation from regression (Sdi), (c) ecovalence (Wi), (d) Hühn stability (Sli), and (e) AMMI stability value.
A standard multifactor analysis of variance test showed that the main effects due to genotypes, locations, and the interaction (genotype × locations) were highly significant. The highly significant interactions indicate that genotypes need to be tested during several years and at different locations for selecting the most stable one. The results showed that all statistical analyses allowed classifying the 25 studied genotypes according to their grain yield level (low, medium, or high), their adaptability to different environments.
Tahent variety was confirmed to be most valuable due to its high production level, stability and its adaptability to variable environments including unfavorable ones.
Antibiotic resistance of Streptococcus pneumoniae has risen to worrying levels in the past few decades worldwide, and subsequently, effective treatment of respiratory tract infections has become even more challenging. While the need to develop new strategies to combat bacterial infections is urgent, novel antibiotic compounds are no longer a priority of the pharmaceutical industry. However, resistance-modifying agents can alleviate the spread of antibiotic resistance and render existing antibiotics effective again. In the present study, we aimed to determine the combinatory antimicrobial effects of the commercial herbal product Cefabronchin® and antibiotic compounds, such as amoxicillin and clarithromycin, on 6 clinical isolates of S. pneumoniae. Therefore, the minimal inhibitory concentration (MIC) of each agent before and after adding Cefabronchin® at different concentrations was determined by applying the checkerboard method. Sub-inhibitory concentrations of the added Cefabronchin® were found to reduce the MIC down to between 3.4% and 29.2% of the amoxicillin MIC and down to between 10.4% and 45.8% of the clarithromycin MIC in all 6 strains. In conclusion, this study provides evidence for the improved antimicrobial effects of commonly used antibiotics in combination with Cefabronchin® in order to combat infections with antibiotic-resistant S. pneumoniae strains.
Three new genera Coppinsidea, Vandenboomia and Wolseleyidea are described and the genera Ivanpisutia, Lecaniella and Myrionora are resurrected on the basis of a phylogenetic analysis of multi-locus sequence data of the Ramalinaceae including the nuclear protein-coding marker rpb2, the internal transcribed spacer and a fragment of the small mitochondrial subunit. The genus Hertelidea was positioned within the Ramalina clade of the phylogenetic tree of the Ramalinaceae. Bacidia sipmanii, Phyllopsora chlorophaea, P. castaneocincta and Ramalina subbreviuscula were recorded from South Korea for the first time here confirming by molecular data, too.
Forty-eight new combinations are proposed: Bacidia alnetorum (basionym: Biatora alnetorum S. Ekman et Tønsberg), Biatora amazonica (basionym: Phyllopsora amazonica Kistenich et Timdal), Biatora cuyabensis (basionym: Lecidea cuyabensis Malme), Biatora halei (basionym: Pannaria halei Tuck.), Biatora kalbii (basionym: Phyllopsora kalbii Brako), Biatora subhispidula (basionym: Psoroma subhispidulum Nyl.), Coppinsidea alba (basionym: Catillaria alba Coppins et Vězda), Coppinsidea aphana (basionym: Lecidea aphana Nyl.), Coppinsidea croatica (basionym: Catillaria croatica Zahlbr.), Coppinsidea fuscoviridis (basionym: Bilimbia fuscoviridis Anzi), Coppinsidea pallens (basionym: Bilimbia pallens Kullh.), Coppinsidea ropalosporoides (basionym: Gyalidea ropalosporoides S. Y. Kondr., L. Lőkös et J.-S. Hur), Coppinsidea scotinodes (basionym: Lecidea scotinodes Nyl.), Coppinsidea sphaerella (basionym: Lecidea sphaerella Hedl.), Ivanpisutia hypophaea (basionym: Biatora hypophaea Printzen et Tønsberg), Ivanpisutia ocelliformis (basionym: Lecidea ocelliformis Nyl.), Lecaniella belgica (basionym: Lecania belgica van den Boom et Reese Naesb.), Lecaniella cyrtellina (basionym: Lecanora cyrtellina Nyl.), Lecaniella dubitans (basionym: Lecidea dubitans Nyl.), Lecaniella erysibe (basionym: Lichen erysibe Ach.), Lecaniella hutchinsiae (basionym: Lecanora hutchinsiae Nyl.), Lecaniella naegelii (basionym: Biatora naegelii Hepp), Lecaniella prasinoides (basionym: Lecania prasinoides Elenkin), Lecaniella sylvestris (basionym: Biatora sylvestris Arnold), Lecaniella tenera (basionym: Scoliciosporum tenerum Lönnr.), Mycobilimbia albohyalina (basionym: Lecidea anomala f. albohyalina Nyl.), Mycobilimbia cinchonarum (basionym: Triclinum cinchonarum Fée), Mycobilimbia concinna (basionym: Phyllopsora concinna Kistenich et Timdal), Mycobilimbia ramea (basionym: Bacidina ramea S. Ekman), Mycobilimbia siamensis (basionym: Phyllopsora siamensis Kistenich et Timdal), Myrionora australis (basionym: Biatora australis Rodr. Flakus et Printzen), Myrionora ementiens (basionym: Lecidea ementiens Nyl.), Myrionora flavopunctata (basionym: Lecanora flavopunctata Tønsberg), Myrionora globulosa (basionym: Lecidea globulosa Flörke), Myrionora hemipolia (basionym: Lecidea arceutina f. hemipolia Nyl.), Myrionora lignimollis (basionym: Biatora ligni-mollis T. Sprib. et Printzen), Myrionora malcolmii (basionym: Phyllopsora malcolmii Vězda et Kalb), Myrionora vacciniicola (basionym: Lecidea vacciniicola Tønsberg), Phyllopsora agonimioides (basionym: Coenogonium agonimioides J. P. Halda, S.-O. Oh et J.-S. Hur), Phyllopsora sunchonensis (basionym: Agonimia sunchonensis S. Y. Kondr. et J.-S. Hur), Vandenboomia chlorotiza (basionym: Lecidea chlorotiza Nyl.), Vandenboomia falcata (basionym: Lecania falcata van den Boom, M. Brand, Coppins, Magain et Sérus.), Wolseleyidea africana (basionym: Phyllopsora africana Timdal et Krog), Wolseleyidea byssiseda (basionym: Lecidea byssiseda Nyl. ex Hue), Wolseleyidea canoumbrina (basionym: Lecidea canoumbrina Vain.), Wolseleyidea furfurella (basionym: Phyllopsora furfurella Kistenich et Timdal), Wolseleyidea ochroxantha (basionym: Lecidea ochroxantha Nyl.), and Wolseleyidea swinscowii (basionym: Phyllopsora swinscowii Timdal et Krog). The combination Biatora longispora (Degel.) Lendemer et Printzen is validated here. The new names Biatora vezdana for Lecania furfuracea Vĕzda and Coppinsidea vainioana for Lecidea sphaeroidiza Vain. are proposed. The phenomenon of presence of ‘extraneous mycobiont DNA’ in lichen association, i.e. DNA, belonging neither to mycobiont nor photobiont or to endophytic fungi is for the first time illustrated. So the presence of nrITS and mtSSU sequences of crustose lichen Coppinsidea ropalosporoides in thalli of crustose Verrucaria margacea and foliose Kashiwadia orientalis, as well as nrITS of Phyllopsora sp. KoLRI in Agonimia pacifica and Biatora longispora, or nrITS and mtSSU of Biatora longispora in thalli of Agonimia pacifica, Oxneriopsis oxneri and Pyxine limbulata, Ivanpisutia oxneri in thalli of Rinodina xanthophaea, etc. is documented. Scarce cases of presence of ‘extraneous mycobiont DNA’ in representatives of the Teloschistaceae, Physciaceae known from literature data are discussed, too.
Existing networks of nature reserves contain a biased sample of biodiversity. In Patagonia Argentina, most nature reserves focus their protection objectives on a particular ecosystem, geoform or scenic value, and usually are located in inaccessible areas. However, unique species or assemblages could inhabit less protected ecosystems, areas or habitats, which could be threatened depending of management. In this study, we assessed the conservation value of different ecosystem types and areas (fjords) in Isla de los Estados Provincial Reserve (RPIE, Argentina), using birds as study case. We chose three fjords (east, central and west) and five ecosystems types (forests at low and high elevation, open-lands at low and high elevation, and sea coasts). Bird's assemblage richness, density, biomass, trophic level, migratory status, and use of strata per ecosystems and fjords were characterized in 75 points (3 fjords × 5 ecosystems × 5 replicates) and evaluated using ANOVA and multivariate methods. Also, Shannon (H') and Pielou (J) indices were estimated for fjords and ecosystems. Passerine was the most abundant group, being mainly residents, omnivorous and carnivorous-scavenger, and they were observed mainly flying or in the canopy. Assemblage structure and function varied with ecosystem types, with higher richness and biomass in coasts and open-lands than in other ecosystems, but with greater density in forests. Multivariate analyses showed conspicuous groups for forests and coast sampling units, with significant differences among all ecosystem types except between low and high forests. Also, east fjord significantly differed in density and biomass from the others, but west fjord also differed in structure, function and bird assemblage. We conclude that greater conservation value must be assigned to ecosystem types or areas inhabited by threatened species (as open-lands at high elevation) and highest richness and variety of use of strata (as sea coasts). However, bird assemblage patterns have particularities in less valuable ecosystems and areas, which also justify their importance for conservation, or at least, prescriptions of low impact uses and activities in the management planning. Nature reserves are opportunities to preserve endemic species, habitats or areas of special interest, as low latitude or unique isolated landscape communities, and ecosystems underrepresented in the network of local, regional or world protected areas.
Biofouling is predicted to increase in the course of global warming, making the study and monitoring of its ecological and economic consequences of great importance. The present study describes, for the first time, recruitment and successional patterns of fouling communities in the Caspian Sea. During one year, short-term panels (STP; replaced every 2 months) and long-term panels (LTP; retrieved after 4, 8 and 12 months) were deployed in the Western Iranian coast of the Caspian Sea. Temporal trends in both sets of panels were evaluated through Generalized Additive Models and discussed in light of the environmental variables registered in each sampling event. Recruitment and successional patterns observed at the community level were mainly driven by barnacles and bryozoans, the dominant taxa over the entire sampling period. Panel coverage, biomass and inorganic to organic matter ratio exhibited clear seasonal patterns in STP, following temperature and chlorophyll a trends. In LTP, coverage and biomass increased over the study period, while the inorganic to organic matter ratio peaked in summer and decreased during autumn and winter months. These results represent a baseline for future studies on biofouling communities in the Caspian Sea, where this topic has been completely neglected.
Anthropic activities impact ecosystems worldwide thus contributing to the rapid erosion of biodiversity. The failure of traditional strategies targeting single species highlighted ecosystems as the most suitable scale to plan biodiversity management. Network analysis represents an ideal tool to model interactions in ecosystems and centrality indices have been extensively applied to quantify the structural and functional importance of species in food webs. However, many network studies fail in deciphering the ecological mechanisms that lead some species to occupy the most central positions in food webs. To address this question, we built a high-resolution food web of the Gulf of California and quantified species position using 15 centrality indices and the trophic level. We then modelled the values of each index as a function of traits and other attributes (e.g., habitat). We found that body size and mobility are the best predictors of indices that characterize species importance at local, meso- and global scale, especially in presence of data accounting for energy direction. This result extends previous findings that illustrated how a restricted set of traitaxes can predict whether two species interact in food webs. In particular, we show that traits can also help understanding the way species are affected by and mediate indirect effects. The traits allow focusing on the processes that shape the food web, rather than providing case-specific indications as the taxonomy-based approach. We suggest that future network studies should consider the traits to explicitly identify the causal relationships that link anthropic impacts to role changes of species in food webs.
Seagrass meadows represent key ecosystems in coastal areas worldwide, hosting a great biodiversity of associated communities and thereby providing a large range of ecosystem services. In this study we present an experimental approach to investigate the effects of seagrass losses on related macrofauna assemblages. Over a three year period, seagrass canopies were removed in experimental plots and changes in epifauna, infauna and respective functional groups were recorded. The experimental removal of seagrass leaves resulted in a decline of 74% of overall macrofaunal abundance and the loss of several taxa. The immediate response of associated communities was followed by the establishment of an alternative assemblage, characterized by an increased number of bioturbators and deposit feeders. The colonization of disturbed seagrass plots by burrowing shrimps (Callianassidae) might have hindered the reestablishment of seagrass after the removal. Our findings highlight the important role of seagrasses as habitat forming species that provide relevant functioning and services in coastal ecosystems.
Plant litter decomposition is a crucial process of nutrient cycling within ecosystems. However, many studies have shown that, apart from its several beneficial effects, organic matter decomposition can be disadvantageous to seed germination, seedling growth, and physiological activity of plants. Litter decomposition was reported to affect both plants and their associated soil microbial communities. The aim of this work was to test the relationships between seed-associated endophytic fungi on the either positive or negative plant's response to different litter types. Leaf material of four species was collected and used in a decomposition experiment inside a growth chamber for 120 days. The plant growth experiment was set in a greenhouse using Trifolium repens and Triticum durum with and without their associated endophytic fungi in the presence of the different litter species at two decay levels (fresh litter and after 120 days of decomposition). Results demonstrated that fresh litter exerted a strong inhibition effect on the plant total biomass when compared to decomposed litter. Moreover, seed-associated endophytic fungi enhanced the inhibitory effect of litter in the observed experimental conditions. The removal of seed-associated endophytic fungi improved the capacity of tested plants to resist to litter inhibitory effect.
Artificial light at night can impact numerous diurnal species by influencing their distribution and habits. In this study, artificial lights placed on the Jacques Cartier bridge in Montreal, Canada were evaluated to determine their impact on insects, insectivorous birds and peregrine falcons. The impact was measured the year the illumination begun and the year following (two years in total). Insect distribution and abundance at three different sites around the bridge was measured. Insectivorous bird abundance and activity were evaluated by observing the cliff swallow as a proxy. Peregrine falcon presence and nesting behavior at the bridge was measured. Insects (aerial and aquatic) were found to be more abundant closer to the illuminated part of the bridge and particularly in the year following the illumination's beginning. Similarly, cliff swallows were more abundant at the bridge the year following the start of the illumination and their activity was more important closer to the illuminated section. Peregrine falcons were only present at the bridge in the year following the beginning of the illumination and specifically at the illuminated part of the bridge. No nesting was detected. These three groups are connected to each other through a food chain in which insect abundance impacts insectivorous bird abundance, which in turn impacts peregrine falcon presence. The illumination therefore positively impacts these three groups separately and together through their food chain. This research highlights the importance of monitoring bird and insect population close to the bridge and further continuation of these observations are necessary to determine if the observed tendency will continue to develop throughout the years.
Plant community diversity is a major research focus in community ecology. The relationship between diversity patterns and different diversity indices is important for developing and improving biodiversity protection. In order to fully understand multi-dimensional diversity patterns of the subalpine meadow on Heyeping peak of Luya Mountain, we used a systematic sampling method and set 150 1 m × 1 m plots in June of 2018. Based on an analysis of the subalpine meadow community on Heyeping peak, we measured multiple diversity indices, carried out a correlation analysis between diversity and environmental factors, and compared correlations among different diversity indices. The goal was to clarify the ecological mechanisms and variation among various diversity indices and environmental factors. The main results were as follows: (1) The species diversity distribution was uniform, the taxonomic level was narrow, functional differences were small, and different pedigree structures were present in each plot. (2) A stable correlation between pedigree diversity index (PD) and species diversity index indicated niche conservativism; the net relatedness index (NRI) of community lineage structure was significantly correlated with the nearest species taxon index (NTI), species richness, and evenness index, indicating that plant community composition in the study area is mainly affected by habitat filtration. (3) The average taxonomic distinctness index (Λ+) and the average taxonomic distinctness index (Λ+) had a stable correlation; only the functional richness index (FRic) and Patrick species richness index were closely related. (4) Among the selected environmental factors, only the forest line had a stable correlation with species diversity index and PD and showed a negative correlation change, indicating an “edge effect” distribution of species diversity in the study area. In summary, the forest line was the key factor affecting the distribution of species diversity in the study area and the species relationships within the community. This work was supported by the National Natural Science Foundation of China (31400358).