scholarly journals Genomic Adaptive Evolution of Sand Rice (Agriophyllum squarrosum) and Its Implications for Desert Ecosystem Restoration

2021 ◽  
Vol 12 ◽  
Author(s):  
Chaoju Qian ◽  
Xia Yan ◽  
Tingzhou Fang ◽  
Xiaoyue Yin ◽  
Shanshan Zhou ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Balancing Selection ◽  
Desert Ecosystem ◽  
Ecological Niches ◽  
Population Divergence ◽  
Desert Plants ◽  
Agriophyllum Squarrosum ◽  
Heterogeneous Habitats ◽  
Wide Range ◽  
Sand Rice

Natural selection is a significant driver of population divergence and speciation of plants. Due to local adaptation to geographic regions with ecological gradients, plant populations harbored a wide range of adaptive genetic variation to enable them to survive the heterogeneous habitats. This is all the more necessary for desert plants, as they must tolerant more striking gradients of abiotic stresses. However, the genomic mechanism by which desert plants adapt to ecological heterogeneity remains unclear, which could help to guide the sustainability of desert ecosystems. Here, using restriction-site-associated DNA sequencing in 38 natural populations, we investigated the genomic divergence and environmental adaptation of sand rice, Agriophyllum squarrosum, an annual pioneer species that covers sand dunes in northern China. Population genetic structure analyses showed that sand rice could be divided into three geographically distinct lineages, namely, Northwest, Central, and East. Phylogeographic analyses revealed that the plant might originate locally in Bergen County and further differentiated into the East lineage and then the Central lineage. Ecological niche modeling found that different lineages occupied distinct ecological niches, suggesting that the ecological gradient would have triggered genomic differentiation among sand rice lineages. Ecological association study supported that the three SNPs under divergent selection were closely correlated with precipitation gradients, indicating that precipitation might be the most important stress trigger for lineage diversity in sand rice. These adaptive SNPs could be used to genotype suitable germplasms for the ecological restoration of specific desertified lands. Further analyses found that genetic structure could significantly overestimate the signals for balancing selection. Within the Central lineage, we still found that 175 SNPs could be subject to balancing selection, which could be the means by which sand rice maintains genetic diversity and adapts to multiple stresses across heterogeneous deserts and sandy lands. From a genomic point of view, this study highlighted the local and global adaptation patterns of a desert plant to extreme and heterogeneous habitats. Our data provide molecular guidance for the restoration of desertified lands in the arid and semi-arid regions of China and could facilitate the marker assistant breeding of this potential crop to mitigate climate change.

scholarly journals Genetic variation and cryptic lineage diversity of the Nigerian red-headed rock agama Agama agama associate with eco-geographic zones

2019 ◽  
Vol 65 (6) ◽  
pp. 713-724 ◽  
Author(s):  
Lotanna M Nneji ◽  
Adeniyi C Adeola ◽  
Fang Yan ◽  
Agboola O Okeyoyin ◽  
Ojo C Oladipo ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Geographic Distance ◽  
Climatic Conditions ◽  
Population Divergence ◽  
Geographic Isolation ◽  
Genetic Structuring ◽  
Derived Savanna ◽  
Wide Range ◽  
Conservation Actions ◽  
The Impact

AbstractNigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism. Among its vertebrate fauna, reptiles have broad distributions, thus, they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification. The red-headed rock agama, Agama agama, lives in a wide range of habitats and, thus, it may show genetic structuring and diversification. Herein, we tested the hypothesis that ecology affects its genetic structure and population divergence. Bayesian inference phylogenetic analysis of a mitochondrial DNA (mtDNA) gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions. Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecological niche model for the matrilines had a good fit and robust performance. Population divergence along the environmental axes was associated with climatic conditions, and temperature ranked highest among all environmental variables for forest specialists, while precipitation ranked highest for the forest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that niche conservatism promotes geographic isolation of the western populations of Nigerian A. agama. Thus, ecological gradients and geographic isolation impact the genetic structure and population divergence of the lizards. This species might be facing threats due to recent habitat fragmentation, especially in western Nigeria. Conservation actions appear necessary.

scholarly journals Unlocking the Patterns of the Tunisian Durum Wheat Landraces Genetic Structure Based on Phenotypic Characterization in Relation to Farmer’s Vernacular Name

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 634
Author(s):  
Cyrine Robbana ◽  
Zakaria Kehel ◽  
Karim Ammar ◽  
Carlos Guzmán ◽  
M’Barek Ben Naceur ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Durum Wheat ◽  
Smallholder Farmers ◽  
Phenotypic Variability ◽  
Phenotypic Characterization ◽  
Ecological Niches ◽  
Dry Conditions ◽  
New Gene ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

During the 1970s, Tunisian durum wheat landraces were replaced progressively by modern cultivars. These landraces are nowadays maintained by smallholder farmers in some ecological niches and are threatened gradually by extinction resulting in the narrowing of the genetic diversity. This study aims to investigate patterns of phenotypic variability using twelve quantitative traits in a panel of 189 durum wheat landraces and seven checks, based on farmer’s population name attribution and genetic structure. Our results showed high phenotypic variability among and within landraces and checks for ten out of twelve studied traits. The principal components analysis showed similar grouping using farmers name attribution and genetic structure using K = 6. These results confirmed the identification of a new gene pool in the oases of Tunisia, represented by the sub-population Jenah Zarzoura and the robustness and high relationships between phenotypic and genome-wide genetic structure using DArTseq method. These findings will enhance the conservation efforts of these landraces and their use in breeding efforts at national and international levels to adapt to dry conditions.

scholarly journals Leeches as the intermediate host for strigeid trematodes: genetic diversity and taxonomy of the genera Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Ewa Pyrka ◽  
Gerard Kanarek ◽  
Grzegorz Zaleśny ◽  
Joanna Hildebrand
Keyword(s):  
Intermediate Host ◽  
Life Cycles ◽  
Coi Gene ◽  
Small Rivers ◽  
Ecological Niches ◽  
Its2 Region ◽  
28S Rrna ◽  
Intermediate Hosts ◽  
Internal Transcribed Spacer Region ◽  
Wide Range

Abstract Background Leeches (Hirudinida) play a significant role as intermediate hosts in the circulation of trematodes in the aquatic environment. However, species richness and the molecular diversity and phylogeny of larval stages of strigeid trematodes (tetracotyle) occurring in this group of aquatic invertebrates remain poorly understood. Here, we report our use of recently obtained sequences of several molecular markers to analyse some aspects of the ecology, taxonomy and phylogeny of the genera Australapatemon and Cotylurus, which utilise leeches as intermediate hosts. Methods From April 2017 to September 2018, 153 leeches were collected from several sampling stations in small rivers with slow-flowing waters and related drainage canals located in three regions of Poland. The distinctive forms of tetracotyle metacercariae collected from leeches supplemented with adult Strigeidae specimens sampled from a wide range of water birds were analysed using the 28S rDNA partial gene, the second internal transcribed spacer region (ITS2) region and the cytochrome c oxidase (COI) fragment. Results Among investigated leeches, metacercariae of the tetracotyle type were detected in the parenchyma and musculature of 62 specimens (prevalence 40.5%) with a mean intensity reaching 19.9 individuals. The taxonomic generic affiliation of metacercariae derived from the leeches revealed the occurrence of two strigeid genera: Australapatemon Sudarikov, 1959 and Cotylurus Szidat, 1928. Phylogenetic reconstructions based on the partial 28S rRNA gene, ITS2 region and partial COI gene confirmed the separation of the Australapatemon and Cotylurus clades. Taking currently available molecular data and our results into consideration, recently sequenced tetracotyle of Australapatemon represents most probably Au. minor; however, unclear phylogenetic relationships between Au. burti and Au. minor reduce the reliability of this conclusion. On the other hand, on the basis of the obtained sequences, supplemented with previously published data, the metacercariae of Cotylurus detected in leeches were identified as two species: C. strigeoides Dubois, 1958 and C. syrius Dubois, 1934. This is the first record of C. syrius from the intermediate host. Conclusions The results of this study suggest the separation of ecological niches and life cycles between C. cornutus (Rudolphi, 1808) and C. strigeoides/C. syrius, with potential serious evolutionary consequences for a wide range of host–parasite relationships. Moreover, phylogenetic analyses corroborated the polyphyletic character of C. syrius, the unclear status of C. cornutus and the separate position of Cotylurus raabei Bezubik, 1958 within Cotylurus. The data demonstrate the inconsistent taxonomic status of the sequenced tetracotyle of Australapatemon, resulting, in our opinion, from the limited availability of fully reliable, comparative sequences of related taxa in GenBank.

scholarly journals Adaptation limits ecological diversification and promotes ecological tinkering during the competition for substitutable resources

2018 ◽  
Vol 115 (44) ◽  
pp. E10407-E10416 ◽  
Author(s):  
Benjamin H. Good ◽  
Stephen Martis ◽  
Oskar Hallatschek
Keyword(s):  
Evolutionary Dynamics ◽  
Competitive Exclusion ◽  
Directional Selection ◽  
Ecological Niches ◽  
Ecological Diversification ◽  
Effective Competition ◽  
Uptake Rates ◽  
Wide Range ◽  
Dynamical Features ◽  
Adaptation Limits

Microbial communities can evade competitive exclusion by diversifying into distinct ecological niches. This spontaneous diversification often occurs amid a backdrop of directional selection on other microbial traits, where competitive exclusion would normally apply. Yet despite their empirical relevance, little is known about how diversification and directional selection combine to determine the ecological and evolutionary dynamics within a community. To address this gap, we introduce a simple, empirically motivated model of eco-evolutionary feedback based on the competition for substitutable resources. Individuals acquire heritable mutations that alter resource uptake rates, either by shifting metabolic effort between resources or by increasing the overall growth rate. While these constitutively beneficial mutations are trivially favored to invade, we show that the accumulated fitness differences can dramatically influence the ecological structure and evolutionary dynamics that emerge within the community. Competition between ecological diversification and ongoing fitness evolution leads to a state of diversification–selection balance, in which the number of extant ecotypes can be pinned below the maximum capacity of the ecosystem, while the ecotype frequencies and genealogies are constantly in flux. Interestingly, we find that fitness differences generate emergent selection pressures to shift metabolic effort toward resources with lower effective competition, even in saturated ecosystems. We argue that similar dynamical features should emerge in a wide range of models with a mixture of directional and diversifying selection.

Botanical Identity of Seasonal Flowering Plants Available and Maintained in the Home Gardens of District Nainital, Uttarakhand

2016 ◽  
Vol 23 (2) ◽  
pp. 89-102
Author(s):  
Kuldeep Negi ◽  
Vandana Tiwari ◽  
Puran Mehta ◽  
Rajni Rawat ◽  
Saraswati Ojha ◽  
...  
Keyword(s):  
Economic Status ◽  
Plant Genetic Resources ◽  
Geographical Area ◽  
Flowering Plants ◽  
Home Gardens ◽  
Flowering Plant ◽  
Ecological Niches ◽  
Wide Range ◽  
Seasonal Flowering ◽  
Flowering Plant Species

Uttarakhand is a store house of plant genetic resources of several crop groups including ornamentals and seasonal flowering plant species. A wide range of seasonal flowering plants are being grown in the region because of its various and favourable agro-geo climatic zones. Ornamental plant enhances aesthetic value of our environment. There are 8 developmental blocks and 1082 villages in district Nainital of Uttarakhand. Nainital district, is a part of Kumaun region of Uttarakhand. It lies between 29?0.1' to 29?36' 21'' N latitude and 78?50' 53'' to 80?06' E longitude. More than 7.62 lakh population reside in 4064 km2 of geographical area of district Nainital. The district falls under sub-tropical to temperate zones. During the course of field survey (2013-2015), we came across wide range of seasonal flowering plants mostly belong to exotic origin being grown in the home gardens of natives of the region situated in different agro-ecological niches. The present study highlighted a total of 150 seasonal flowering plants with 120 genera belonging to 50 families. These were arranged alphabetically with botanical names followed by vernacular and trade name, family, origin or native place, nature, season with appropriate remarks of variation in shape, size and colour, method of propagation with economic status.

Serotonin differentially affects morph-specific behavior in divergent populations of a horned beetle

2019 ◽  
Vol 31 (2) ◽  
pp. 352-360 ◽  
Author(s):  
Keeley D Newsom ◽  
Armin P Moczek ◽  
Daniel B Schwab
Keyword(s):  
Critical Role ◽  
Population Divergence ◽  
Aggressive Behaviors ◽  
Onthophagus Taurus ◽  
Male Condition ◽  
Wide Range ◽  
Behavioral Responsiveness ◽  
Serotonin Signaling ◽  
Characteristic Features ◽  
Serotonin Biosynthesis

Abstract Associations between animal weapons and corresponding aggressive behaviors are among the most characteristic features of species, yet at the same time their co-expression is itself often strongly dependent on context, such as male condition or population ecology. Yet the mechanisms that modulate associations between aggression, morphology, and biological context remain poorly understood. The biogenic amine serotonin has been shown to regulate a wide range of aggressive and morph-specific behaviors in diverse insect species. However, the extent to which serotonin may coordinate the expression of behavior with morphology across biological contexts remains unclear. In this study, we pharmacologically increased serotonin biosynthesis in males of the polyphenic beetle, Onthophagus taurus, and assessed how this manipulation affects both aggressive and non-aggressive behaviors in alternative fighter and sneaker morphs, as well as in males derived from two rapidly diverging populations characterized by disparate levels of competition for mates. We find (i) that enhancing serotonin biosynthesis increases most measures of aggressive behaviors, but influences only a subset of nonaggressive behaviors, (ii) that similar serotonin-mediated behavioral changes manifest in both morphs within populations more often than just a single morph, and (iii) that males derived from the two focal populations have diverged in their behavioral responsiveness to serotonin up-regulation. Collectively, our study suggests that serotonin signaling plays a critical role in the regulation of male behavior and its evolution, including in the context of rapid, short-term population divergence.

The agronomic performance of sand rice (Agriophyllum squarrosum), a potential semi-arid crop species

2018 ◽  
Vol 65 (8) ◽  
pp. 2293-2301
Author(s):  
Jiwei Zhang ◽  
Jiecai Zhao ◽  
Qin Zhou ◽  
Jinling Hu ◽  
Yan Ma ◽  
...  
Keyword(s):  
Agronomic Performance ◽  
Crop Species ◽  
Agriophyllum Squarrosum ◽  
Sand Rice ◽  
Semi Arid

Cephalopod Olfaction

2017 ◽  
Author(s):  
Anna Di Cosmo ◽  
Gianluca Polese
Keyword(s):  
Water Solubility ◽  
Community Organization ◽  
Population Level ◽  
Water Soluble ◽  
Ecological Niches ◽  
Marine Animals ◽  
Odour Source ◽  
Wide Range ◽  
Olfactory Organs ◽  
Chemosensory Systems

Within the Phylum Mollusca, cephalopods encompass a small and complex group of exclusively marine animals that live in all the oceans of the world with the exception of the Black and Caspian seas. They are distributed from shallow waters down into the deep sea, occupying a wide range of ecological niches. They are dominant predators and themselves prey with high visual capability and well-developed vestibular, auditory, and tactile systems. Nevertheless, their perceptions are chemically facilitated, so that water-soluble and volatile odorants are the key mediators of many physiological and behavioral events. For cephalopods as well as the other aquatic animals, chemical cues convey a remarkable amount of information critical to social interaction, habitat selection, defense, prey localization, courtship and mating, affecting not only individual behavior and population-level processes, but also community organization and ecosystem function. Cephalopods possess chemosensory systems that have anatomical similarities to the olfactory systems of land-based animals, but the molecules perceived from distance are different because their water solubility is of importance. Many insoluble molecules that are detected from distance on land must, in an aquatic system, be perceived by direct contact with the odour source. Most of the studies regarding olfaction in cephalopods have been performed considering only waterborne molecules detected by the “olfactory organs.” However cephalopods are also equipped with “gustatory systems” consisting of receptors distributed on the arm suckers in octopods, buccal lips in decapods, and tentacles in nautiluses. To date, what is known about the olfactory organ in cephalopods comes from studies on nautiloids and coleoids (decapods and octopods). In the nautiloid’s olfactory system, there is a pair of rhinophores located below each eye and open to the environment with a tiny pore, whereas in coleoids a small pit of ciliated cells is present on either side of the head below the eyes close to the mantle edge.

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