Intraspecific divergences and phylogeography of Panzerina lanata (Lamiaceae) in northwest China

Climatic fluctuations during the Quaternary significantly affect many species in their intraspecific divergence and population structure across northwest China. In order to investigate the impact of climate change on herbaceous plants, we studied Panzerina lanata (Lamiaceae), a widely distributed species. Sequences of two chloroplast DNA (cpDNA) intergenic spacers (trnH-psbA and rpoB-trnC) and a nuclear ribosomal region (nrDNA, ITS) were generated from 27 populations of Panzerina lanata and resulted in the identification of seven chloroplast haplotypes and thirty-two nuclear haplotypes. We applied AMOVA, neutrality test and mismatch distribution analysis to estimate genetic differentiation and demographic characteristics. The divergence times of the seven cpDNA haplotypes were estimated using BEAST. Our results revealed high levels of genetic diversity (cpDNA: Hcp = 0.6691, HT = 0.673; nrDNA: Hnr = 0.5668, HT = 0.577). High level of genetic differentiation (GST = 0.950) among populations was observed in the cpDNA sequences, while the genetic differentiation values (GST = 0.348) were low in nuclear sequences. AMOVA results revealed major genetic variation among the three groups: northern, central, and eastern group. However, the genetic differentiation in ITS data was not found. The species distribution modeling and demographic analysis indicated that P. lanata had not experienced recent range expansion. The occurrence of divergence between seven cpDNA haplotypes, probably during Pleistocene, coincides with aridification and expansion of the desert across northwest China that resulted in species diversification and habitat fragmentation. In addition, we discovered that the deserts and the Helan Mountains acted as effective geographic barriers that promoting the intraspecific diversity of P. lanata.

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Intraspecific divergences and phylogeography of Panzerina lanata (Lamiaceae) in Northwest China

10.7287/peerj.preprints.26837 ◽

2018 ◽

Author(s):

Yanfen Zhao ◽

Hongxiang Zhang ◽

Borong Pan ◽

Mingli Zhang

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Population Genetic ◽

Divergence Time ◽

Northwest China ◽

Northwestern China ◽

Intraspecific Diversity ◽

Early Pleistocene ◽

Helan Mountains ◽

The Impact

Climactic fluctuations during the Quaternary played a crucial role in genetic diversity and population genetic structure of many plant species in northwestern China. In order to understand the impact of climate change on herbaceous plants, we studied Panzerina lanata (Lamiaceae), a widely distributed species. Two chloroplast DNA intergenic spacers (trnH-psbA and rpoB-trnC) were used to sequence 269 individuals from 27 populations and seven haplotypes were identified. Genetic structure and demographic characteristics were estimated using AMOVA, neutrality tests, and mismatch distribution analyses. The divergence times between the seven haplotypes were estimated using Beast. Our results revealed high levels of total genetic diversity (HT = 0.673±0.0869) and low levels of average within-population genetic diversity (HS = 0.033±0.0214). The analysis of molecular variance indicated major genetic differentiation among the three groups: northern, central, and eastern group. The species distribution modeling and demographic analysis indicated that P. lanata has not experience a recent range expansion. The divergence time within P. lanata occurred between the early Pleistocene and the late Pleistocene, which coincides with aridification and the expansion of the deserts in northwestern China that resulted in species diversification and habitat fragmentation. In addition, we speculate that the deserts and the Helan Mountains acted as effective geographic barriers that led to intraspecific diversity.

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Intraspecific divergences and phylogeography of Panzerina lanata (Lamiaceae) in Northwest China

10.7287/peerj.preprints.26837v1 ◽

2018 ◽

Author(s):

Yanfen Zhao ◽

Hongxiang Zhang ◽

Borong Pan ◽

Mingli Zhang

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Population Genetic ◽

Divergence Time ◽

Northwest China ◽

Northwestern China ◽

Intraspecific Diversity ◽

Early Pleistocene ◽

Helan Mountains ◽

The Impact

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Population expansion and genetic structure in Cephalocereus nizandensis (Cactaceae), a microendemic cactus of rocky outcrops of the Tehuantepec basin, Mexico

Plant Ecology and Evolution ◽

10.5091/plecevo.2021.1773 ◽

2021 ◽

Vol 154 (2) ◽

pp. 217-230

Author(s):

Aldo Isaac Juárez-Miranda ◽

Amelia Cornejo-Romero ◽

Carlos Fabián Vargas-Mendoza

Keyword(s):

Genetic Structure ◽

Genetic Differentiation ◽

Demographic History ◽

Population Expansion ◽

Shannon Index ◽

Distribution Analysis ◽

Isolated Populations ◽

Climatic Fluctuations ◽

Intergenic Sequences ◽

Rocky Outcrops

Background and aims – Cephalocereus nizandensis is a microendemic columnar cactus that grows isolated in xerophytic enclaves associated with rocky outcrops in the Isthmus of Tehuantepec, in the south of Mexico. Its demographic history and genetic structure were assessed to determine the main events that shaped its current restricted distribution.Material and methods – Chloroplast intergenic sequences of 40 individuals and inter simple sequence repeats (ISSRs) of 45 individuals from four isolated populations were used to estimate haplotypic and nucleotide diversity, using expected heterozygosity and the Shannon index. AMOVA, population pair-wise FST, and Bayesian clustering analyses were performed to explore the genetic structure. Demographic history was estimated with neutrality tests, mismatch distribution analysis, and Bayesian skyline plots. Phylogenetic relationships and divergence times were determined using a median joining network and a Bayesian molecular clock.Key results – C. nizandensis has a high diversity and moderate genetic differentiation. The lowest elevation locality was found to be the most genetically distinct. The species has undergone a process of population expansion that began 150,000 years ago and has remained without evidence of a population contraction in the transition from the Pleistocene to the Holocene (11,700 years ago).Conclusions – C. nizandensis presents moderate but significant genetic differentiation, which may be due to an early divergence of its populations. Currently observed levels of genetic diversity are the result of historical maintenance of high population sizes and a population expansion approximately in the last 150,000 years, which was sustained independently of the climatic fluctuations of the Early Quaternary, due in part to the stability of the rocky habitat.

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Delineating the Polarized and Unpolarized Parton Structure of the Nucleon

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194515600538 ◽

2015 ◽

Vol 37 ◽

pp. 1560053

Author(s):

Pedro Jimenez-Delgado

Keyword(s):

Parton Distribution ◽

Distribution Functions ◽

Distribution Analysis ◽

Coupling Constant ◽

Parton Distribution Functions ◽

Careful Treatment ◽

Future Data ◽

The Impact

Reports on our latest extractions of parton distribution functions of the nucleon are given. First an overview of the recent JR14 upgrade of our unpolarized PDFs, including NNLO determinations of the strong coupling constant and a discussion of the role of the input scale in parton distribution analysis. In the second part of the talk recent results on the determination of spin-dependent PDFs from the JAM collaboration are reported, including a careful treatment of hadronic and nuclear corrections, as well as reports on the impact of present and future data in our understanding of the spin of the nucleon.

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The impact of urbanization and aging on food security in developing countries: The view from Northwest China

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.126067 ◽

2021 ◽

Vol 292 ◽

pp. 126067

Author(s):

Xian Liu ◽

Yueyue Xu ◽

Bernie A. Engel ◽

Shikun Sun ◽

Xining Zhao ◽

...

Keyword(s):

Developing Countries ◽

Food Security ◽

Northwest China ◽

Impact Of Urbanization ◽

The Impact

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Influence of Quaternary environmental changes on mole populations inferred from mitochondrial sequences and evolutionary rate estimation

Zoological Letters ◽

10.1186/s40851-021-00169-9 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Azusa Nakamoto ◽

Masashi Harada ◽

Reiko Mitsuhashi ◽

Kimiyuki Tsuchiya ◽

Alexey P. Kryukov ◽

...

Keyword(s):

Genetic Diversity ◽

Environmental Changes ◽

Late Quaternary ◽

Population Expansion ◽

Rapid Expansion ◽

Dependent Manner ◽

Distribution Analysis ◽

Land Bridge ◽

Mismatch Distribution Analysis ◽

Expansion Event

AbstractQuaternary environmental changes fundamentally influenced the genetic diversity of temperate-zone terrestrial animals, including those in the Japanese Archipelago. The genetic diversity of present-day populations is taxon- and region-specific, but its determinants are poorly understood. Here, we analyzed cytochrome b gene (Cytb) sequences (1140 bp) of mitochondrial DNA (mtDNA) to elucidate the factors determining the genetic variation in three species of large moles: Mogera imaizumii and Mogera wogura, which occur in central and southern mainland Japan (Honshu, Shikoku, and Kyushu), and Mogera robusta, which occurs on the nearby Asian continent. Network construction with the Cytb sequences revealed 10 star-shaped clusters with apparent geographic affinity. Mismatch distribution analysis showed that modes of pairwise nucleotide differences (τ values) were grouped into five classes in terms of the level, implying the occurrence of five stages for rapid expansion. It is conceivable that severe cold periods and subsequent warm periods during the late Quaternary were responsible for the population expansion events. The first and third oldest events included island-derived haplotypes, indicative of the involvement of land bridge formation between remote islands, hence suggesting an association of the ends of the penultimate (PGM, ca. 130,000 years ago) and last (LGM, ca. 15,000 years ago) glacial maxima, respectively. Since the third event was followed by the fourth, it is plausible that the termination of the Younger Dryas and subsequent abrupt warming ca. 11,500 years ago facilitated the fourth expansion event. The second event most likely corresponded to early marine isotope stage (MIS) 3 (ca. 53,000 years ago) when the glaciation and subsequent warming period were predicted to have influenced biodiversity. Utilization of the critical times of 130,000, 53,000, 15,000, and 11,500 years ago as calibration points yielded evolutionary rates of 0.03, 0.045, 0.10 and 0.10 substitutions/site/million years, respectively, showing a time-dependent manner whose pattern was similar to that seen in small rodents reported in our previous studies. The age of the fifth expansion event was calculated to be 5800 years ago with a rate of 0.10 substitutions/site/million years ago during the mid-Holocene, suggestive of the influence of humans or other unspecified reasons, such as the Jomon marine transgression.

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全球变暖对我国西北地区小麦生产的影响The Impact of Global Warming on Wheat Yields in Northwest China

Climate Change Research Letters ◽

10.4236/ccrl.2012.12006 ◽

2012 ◽

Vol 01 (02) ◽

pp. 51-58

Author(s):

沈小波

Keyword(s):

Global Warming ◽

Northwest China ◽

The Impact

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The impact of floral morphology on genetic differentiation in two closely related biennial plant species

AoB Plants ◽

10.1093/aobpla/ply051 ◽

2018 ◽

Vol 10 (5) ◽

Cited By ~ 1

Author(s):

Arne Mertens ◽

Rein Brys ◽

Dorien Schouppe ◽

Hans Jacquemyn

Keyword(s):

Genetic Differentiation ◽

Plant Species ◽

Floral Morphology ◽

The Impact

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Variation of Runoff and Runoff Components of the Upper Shule River in the Northeastern Qinghai–Tibet Plateau under Climate Change

Water ◽

10.3390/w13233357 ◽

2021 ◽

Vol 13 (23) ◽

pp. 3357

Author(s):

Jinkui Wu ◽

Hongyuan Li ◽

Jiaxin Zhou ◽

Shuya Tai ◽

Xueliang Wang

Keyword(s):

Climate Change ◽

Sustainable Use ◽

Reduction Rate ◽

Northwest China ◽

Tibet Plateau ◽

Glacier Area ◽

Rainfall Runoff ◽

Total Runoff ◽

Increasing Temperature ◽

The Impact

Quantifying the impact of climate change on hydrologic features is essential for the scientific planning, management and sustainable use of water resources in Northwest China. Based on hydrometeorological data and glacier inventory data, the Spatial Processes in Hydrology (SPHY) model was used to simulate the changes of hydrologic processes in the Upper Shule River (USR) from 1971 to 2020, and variations of runoff and runoff components were quantitatively analyzed using the simulations and observations. The results showed that the glacier area has decreased by 21.8% with a reduction rate of 2.06 km2/a. Significant increasing trends in rainfall runoff, glacier runoff (GR) and baseflow indicate there has been a consistent increase in total runoff due to increasing rainfall and glacier melting. The baseflow has made the largest contribution to total runoff, followed by GR, rainfall runoff and snow runoff, with mean annual contributions of 38%, 28%, 18% and 16%, respectively. The annual contribution of glacier and snow runoff to the total runoff shows a decreasing trend with decreasing glacier area and increasing temperature. Any increase of total runoff in the future will depend on an increase of rainfall, which will exacerbate the impact of drought and flood disasters.

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Hydro-climatic fluctuations and their impact on Lake Abhe environments (Ethiopia & Djibouti): a lesson from the past 10,000 years

10.5194/egusphere-egu21-4634 ◽

2021 ◽

Author(s):

Carlo Mologni ◽

Laurent Bruxelles ◽

Fabien Arnaud ◽

Pierre Sabatier ◽

Anne-Lise Develle ◽

...

Keyword(s):

East African ◽

Climatic Fluctuations ◽

Climatic Oscillations ◽

Sedimentary Records ◽

Hydrological Changes ◽

Precession Cycle ◽

Afar Region ◽

Geomorphic Features ◽

Sedimentary System ◽

The Impact

Throughout the last 14 ka, tropical Africa experienced significant hydrological changes that were mainly driven by the orbital precession cycle, which controls the intensity of the African monsoon. Recent studies conducted in lake and deltaic sedimentary records suggest that long-term monsoon humid oscillations (African Humid Period / AHP ~14 &#8211; ~6 ka) were punctuated by centennial-scale episodes of hyperaridity. However, the abrupt or gradual aridification modalities since the end of the AHP and the modalities of the centennial-scale episodes, as well as their impacts on past and current environments are still debated.The Lake Abhe basin in the Central Afar region (Ethiopia & Djibouti) is the endorheic receptacle of freshwater originating in the Ethiopian Highlands, and represents a hydro-sedimentary system sensitive to hydro-climatic changes in East Africa. Today it is characterized by residual lakes (Gamari and Afambo lakes) and a hyper-arid climate, while during the AHP, the Abhe basin was occupied by a Mega-lake and by humid environmental conditions. Holocene climatic disruptions drastically changed the landscapes and ways of life along this basin.&#160;&#160;The aim of this study is to describe, interpret and estimate the impact of hydro-climatic oscillations on the evolution of Lake Abhe&#8217;s littoral lacustrine environments and palaeolandscapes since the AHP from different viewpoints.Indeed, this research combines paleoclimatological and geomorphological studies based on a new set of 14C ages on two lacustrine cores and on several morpho-sedimentary outcrops spanning the Early to Late Holocene. Our results allow us to: a) refine the temporal occurrence and the hydrological modalities of the AHP including short-term arid episodes linked to Younger Dryas and 8.2 ka North Atlantic events; b) recognise some paleo-shoreline geomorphic features linked to lake level fluctuations, as well as the development littoral pedological horizons and the activation/shutdown of the perilacustrine fluvial network during humid and arid events; c) track these changes until the present day, and discuss their evolution scenario in the near future.Comparing with other regional climatic records, we show how Lake Abhe basin was highly reactive to East African monsoonal regimes, and how current hydrological changes could impact its environments.&#160; &#160;&#160;&#160;&#160;

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