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Vegetation-environment relationship in Pinus wallichiana forests of the Swat Hindukush range of Pakistan

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Journal of Forestry Research 2020年第1期31卷 185-195页

作者： Inayat Ur Rahman Nasrullah Khan Kishwar Ali Siraj Ahmad Laboratory of plant ecology and Dendrochronology Department of BotanyUniversity of Malakand

Understanding the influence of environmental variables on the spatial distribution of ecological communities is essential to predict the response of vegetation to various environmental *** theory suggests that multiple environmental factors shape local species assemblages and should influence the various components of community structure and composition in different *** study aimed to classify Pinus wallichiana dominated forests in the Swat Hindukush range mountains to understand the relative influence of multiple environmental filters on its composition and *** forests represent the most typical of the species distribution in northern Pakistan and were not subjected to any phytosociological *** this purpose,thirty forest stands,spanning a wide range of physical habitats were sampled using 10 x 10 m plots and the importance value index was *** floristic and environmental data were subjected to Ward’s agglomerative cluster analysis for objective classification and ordinated with NMS ordination for pattern description and testing the vegetation-environmental *** floristically and ecologically distinct communities were recognized along the topographic gradient(elevation,r=0.377;slope,r=0.5548) coupled with soil physical(clay,r=0.2782;silt,r=0.3225) and chemical properties(pH,r=0.4975;lime,r=3982).An elevation gradient of 100 m separated the low(Pinus wallichiana-Quercus dilatata community)and middle elevations forest stands(*** pure population) from the highland population type(Pinus wallichiana-Cedrus deodara community).The floristics and structure of these forest types respond directly or indirectly to topographic and soil variables which were evidenced from the floristic composition,species richness,and community *** characteristics of the communities changed from heterogenous,dense stands to sparsely dispersed conifers,broadleaved-evergreen,and deciduous vegetation types along

关键词： Blue pine forests Classification-ordination Ecological gradient Hindukush range mountains Species composition

Epigenetics in the modern era of crop improvements

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Science China Life Sciences 2025年

作者： Yan Xue Xiaofeng Cao Xiangsong Chen Xian Deng Xingwang Deng Yong Ding Aiwu Dong Chengguo Duan Xiaofeng Fang Lei Gong Zhizhong Gong Xiaofeng Gu Chongsheng He Hang He Shengbo He Xinjian He Yan He Yuehui He Guifang Jia Danhua Jiang Jianjun Jiang Jinsheng Lai Zhaobo Lang Chenlong Li Qing Li Xingwang Li Bao Liu Bing Liu Xiao Luo Yijun Qi Weiqiang Qian Guodong Ren Qingxin Song Xianwei Song Zhixi Tian Jiawei Wang Yuan Wang Liang Wu Zhe Wu Rui Xia Jun Xiao Lin Xu Zhengyi Xu Wenhao Yan Hongchun Yang Jixian Zhai Yijing Zhang Yusheng Zhao Xuehua Zhong Daoxiu Zhou Ming Zhou Yue Zhou Bo Zhu Jiankang Zhu Qikun Liu College of Life Sciences Institute of Life Science and Green Development Hebei University Biotechnology Research Institute Chinese Academy of Agricultural Sciences College of Biology Hunan Key Laboratory of Plant Functional Genomics and Developmental Regulation Hunan Engineering and Technology Research Center of Hybrid Rapeseed Hunan University Institute of Advanced Agricultural Sciences School of Advanced Agricultural Sciences Peking University State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangdong Laboratory for Lingnan Modern Agriculture South China Agricultural University National Institute of Biological Sciences Key Laboratory of Seed Innovation Institute of Genetics and Developmental Biology Chinese Academy of Sciences School of Advanced Agricultural Sciences Peking-Tsinghua Center for Life Sciences Peking University Synthetic and Functional Biomolecules Center Beijing National Laboratory for Molecular Sciences Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry and Molecular Engineering Peking University Key Laboratory of Seed Innovation State Key Laboratory of Plant Genomics and National Center for Plant Gene Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences State Key Laboratory of Wheat Improvement Peking University Institute of Advanced Agricultural Sciences Shandong Laboratory of Advanced Agricultural Sciences in Weifang State Key Laboratory of Crop Stress Adaptation and Improvement School of Life Sciences Henan University State Key Laboratory of Maize Bio-breeding National Maize Improvement Center Department of Plant Genetics and Breeding China Agricultural University Frontiers Science Center for Molecular Design Breeding China Agricultural University Center for Crop Functional Genomics and Molecular Breeding China Agricultural University Sanya Institute of China Agricultural University Hainan Yazhou Bay Seed Laboratory Institute of Advan

Epigenetic mechanisms are integral to plant growth, development, and adaptation to environmental stimuli. Over the past two decades,our comprehension of these complex regulatory processes has expanded remarkably, producing a substantial body of knowledge on both locus-specific mechanisms and genome-wide regulatory patterns. Studies initially grounded in the model plant Arabidopsis have been broadened to encompass a diverse array of crop species, revealing the multifaceted roles of epigenetics in physiological and agronomic traits. With recent technological advancements, epigenetic regulations at the single-cell level and at the large-scale population level are emerging as new focuses. This review offers an in-depth synthesis of the diverse epigenetic regulations, detailing the catalytic machinery and regulatory functions. It delves into the intricate interplay among various epigenetic elements and their collective influence on the modulation of crop traits. Furthermore, it examines recent breakthroughs in technologies for epigenetic modifications and their integration into strategies for crop improvement. The review underscores the transformative potential of epigenetic strategies in bolstering crop performance, advocating for the development of efficient tools to fully exploit the agricultural benefits of epigenetic insights.

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Variation and heritability of morphological and physiological traits among Leymus chinensis genotypes under different environmental conditions

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Journal of Arid Land 2019年第1期11卷 66-74页

作者： YANG Xue LI Junpeng ZHAO Tingting MO Lidong ZHANG Jianli REN Huiqin ZHAO Nianxi GAO Yubao department of plant Biology and ecology College of Life Science Nankai University

Intraspecific trait variation and heritability in different environmental conditions not only suggest a potential for an evolutionary response but also have important ecological consequences at the population, community, and ecosystem levels. However, the contribution of quantitative trait variation within a grassland species to evolutionary responses or ecological consequences is seldom documented. Leymus chinensis is an important dominant species in semi-arid grasslands of China, which has seriously suffered from drought and high temperature stresses in recent decades. In the present study, we measured variation and heritability of 10 quantitative traits, namely the number of tillers, maximum shoot height, number of rhizomes, maximum rhizome length, rhizome mass, aboveground mass, root mass, maximum net photosynthetic rate(Pmax), specific leaf area(SLA), and leaf length to leaf width ratio(LL/LW), for 10 genotypes of L. chinensis under one non-stress(Ck) condition and three environmental stress conditions(i.e., drought(Dr), high temperature(Ht), and both drought and high temperature(DrHt)). Result indicated that(1) the interaction of genotype and environmental condition(G×E) was significant for 6 traits but not significant for the other 4 traits as shown by two-way analysis of variance(ANOVA), suggesting that different selection forces were placed for different traits on the factors dominating phenotypic responses to different environmental conditions. Moreover, these significant G×E effects on traits indicated significantly different phenotypic adaptive responses among L. chinensis genotypes to different environmental conditions. Additionally, individuals could be grouped according to environmental condition rather than genotype as shown by canonical discriminant analysis, indicating that environmental condition played a more important role in affecting phenotypic variation than genotype;(2) by one-way ANOVA, significant differences among L. chinensis genotypes w

关键词： Leymus chinensis genotype quantitative trait variation heritability drought high temperature

Leaf and Ecosystem Gas Exchange Responses of Buffel Grass-Dominated Grassland to Summer Precipitation

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Pedosphere 2015年第1期25卷 112-123页

作者： Mir Zaman HUSSAIN Gnaana SARASWATHI Chhakchhuak LALRAMMAWIA Dennis OTIENO Kailash PALIWAL John TENHUNEN department of plant ecology University of Bayreuth Institute for Genomic Biology University of Illinois department of plant Sciences Madurai Kamaraj University

Sporadic rain events that occur during summer play an important role in the initiation of biological activity of semi-arid *** understand how ecosystem processes of a buffel grass(Cenchrus ciliaris L.)-dominated grassland respond to summer rain events,an LI 6 400 gas exchange system was used to measure the leaf gas exchange and plant canopy chambers were used to measure net ecosystem CO2exchange(NEE) and ecosystem respiration(Reco), which were made sequentially during periods before rain(dry) and after rain(wet). Gross ecosystem photosynthesis(GEP) was estimated from NEE and Reco fluxes, and light use efficiency parameters were estimated using a rectangular hyperbola model. Prior to the monsoon rain, grassland biomass was non-green and dry exhibiting positive NEE(carbon source) and low GEP values during which the soil water became increasingly scarce. An initial rain pulse(60 mm) increased the NEE from pre-monsoon levels to negative NEE(carbon gain) with markedly higher GEP and increased green biomass. The leaf photosynthesis and leaf stomatal conductance were also improved substantially. The maximum net CO2uptake(i.e.,negative NEE) was sustained in the subsequent period due to multiple rain events. As a result, the grassland acted as a net carbon sink for 20 d after first rain. With cessation of rain(drying cycle), net CO2 uptake was reduced to lower values. High sensitivity of this grassland to rain suggests that any decrease in precipitation in summer may likely affect the carbon sequestration of the semiarid ecosystem.

关键词： biomass CO2 exchange photosynthesis respiration soil moisture stomatal conductance

Genetic Improvement of Willow for Bioenergy and Biofuels

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Journal of Integrative plant Biology 2011年第2期53卷 151-165页

作者： Angela Karp Steve J.Hanley Sviatlana O.Trybush William Macalpine Ian Shield Centre for Bioenergy and Climate Change Plant and Invertebrate Ecology DepartmentRothamsted Research

Willows （Salix spp.） are a very diverse group of catkin-bearing trees and shrubs that are widely distributed across temperate regions of the globe. Some species respond well to being grown in short rotation coppice （SRC） cycles, which are much shorter than conventional forestry. Cop- picing reinvigorates growth and the biomass rapidly accumulated can be used as a source of renewable carbon for bioenergy and biofuels. As SRC willows re-distribute nutrients during the perennial cycle they require only minimal nitrogen fertilizer for growth. This results in fuel chains with potentially high greenhouse gas reductions. To exploit their potential for renewable energy, willows need to be kept free of pests and diseases and yields need to be improved without significantly increasing the requirements for fertilizers and water. The biomass composition needs to be optimized for different end-uses. Yields also need to be sustainable on land less productive for food crops to reduce conflicts over land use. Advances in understanding the physiology and growth of willow, and in the identification of genes underlying key traits, are now at the stage where they can start to be used in breeding programs to help achieve these goals.

关键词： Genetic Improvement of Willow for Bioenergy and Biofuels QTLs SRC

Success of three soil restoration techniques on seedling survival and growth of three plant species in the Sahel of Burkina Faso(West Africa)

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Journal of Forestry Research 2016年第2期27卷 313-320页

作者： Philippe Bayen Anne Mette Lykke Adjima Thiombiano Laboratory of plant Biology and ecology University of Ouagadougou department of Bioscience Aarhus University

In the Sahel of Africa, where 90 % of the population depends on natural resources for their liveli- hood, a large part of the soils are structurally unstable, prone to crusting and hard setting, and have low water holding capacity, which hamper vegetation establishment. The effect of soil restoration techniques on survival and growth of seedlings of Acacia nilotica, Acacia tortilis and Jatropha curcas was tested in completely barren, degraded land in a Sahelian ecosystem in Burkina Faso. A total of 522 seedlings （174 plants of each plant species） were planted in a randomized complete block design with three replicates combining three soil preparation techniques： half-moon, zai＂ and standard plantation. Survival and growth rates evaluated over 20 months were significantly higher using the half-moon technique compared with the other two techniques. Survival rates of plant species planted using half-moon technique were 62.5, 28.57 and 10.71% for A. nilotica, A. tortilis and J. curcas respec- tively, but in za＇i and standard planting, seedling survival was zero. The low survival rate of J. curcas using the half-moon technique may indicate that J. curcas is unsuit- able for barren and degraded land, whereas A. nilotica and A. tortilis appear to be promising tree species for rehabil- itation of degraded land.

关键词： Afforestation Bare soil Soil rehabilitation Species selection Water conservation

Revisiting taxonomy,morphological evolution,and fossil calibration strategies in Chloranthaceae

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Journal of Systematics and Evolution 2011年第4期49卷 315-329页

作者： Alexandre ANTONELLI Taylor S.FEILD Gothenburg Botanical Garden and department of plant and Environmental Sciences University of Gothenburg department of ecology and Evolutionary Biology University of Tennessee

Chloranthaceae is one of the earliest diverging angiosperm families and is comprised of approximately 75 species in four genera (Chloranthus,Sarcandra,Ascarina,and Hedyosmum).This family has received considerable attention because of its seemingly primitive morphology,disjunct tropical distribution in Asia and America,and extensive fossil record from the Early *** the present study,we reconstructed the phylogeny of Chloran- thaceae based on a combined dataset of three plastid DNA regions and 56 *** then estimated divergence times in the family using two relaxed molecular clock methods (BEAST and penalized likelihood).We focused on testing the influence of fossil taxa in calibrating the molecular phylogeny,and on assessing the current taxonomy of the family in light of the phylogenetic *** results indicate that most intrageneric divisions within Asca-rina and Hedyosmum are not *** results from the dating analysis suggest that the Hedyosmum-like fossil Asteropollis represents a stem lineage of Hedyosmum,as has been suggested previously from morphological *** contrast,our results indicate that the Chloranthus-like fossil Chloranthistemon,previously suggested on morphological grounds to be a stem relative of Chloranthus,may,instead,belong to the branch leading to the clade Chloranthus + *** median crown ages of Chloranthus,Sarcandra,Ascarina,and Hedyosmum estimated in the BEAST analysis were 26.3,9.5,31.0 and 45.8 million years ago (Ma),respectively,whereas the divergence between Chloranthus and Sarcandra,the splitting of Ascarina with the former two genera,and Hedyos- mum separating from the three genera were estimated to 63.8,95.7 and 111.1 *** present study sheds further light on the temporal evolution of Chloranthaceae and exemplifies how molecular dating analyses may be used to explore alternative phylogenetic placements of fossil taxa.

关键词： angiosperm evolution Asteropollis Chloranthaceae Chloranthistemon molecular dating phylogeny.

Phytosociology, structure and dynamics of Pinus roxburghii associations from Northern Pakistan

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Journal of Forestry Research 2014年第3期25卷 511-521页

作者： Nasrullah Khan Kishwar Ali Shahid Shaukat Laboratory of plant ecology and department of Botany University of Malakand Chakdara department of plant Sciences School of Biological Sciences University of Reading department of Botany Federal Urdu University

We investigated the phytosociology, structure and dynamics of Pinus roxburghii in 40 stands in northern areas of Pakistan by using cluster analysis （Ward’s agglomerative clustering） and ordination （Non-metric Multidimensional Scaling）. Cluster analysis revealed three major groups associated with specific environmental characteristics：（1） P. roxburghii （2） Pinus-Quercus baloot and （3） Pinus-Olea ferruginea community types. NMS-ordination showed the major gradient as an amalgam of elevation （r2=0.441, p＆lt;0.01） and slope （r2=0.391, p＆lt;0.05） as the two topographic factors correlated with species distribution. The first ordination axis also showed positive correlation with soil variables like pH and electrical conductivity, suggesting that soil chemistry was related to topographic characteristics and probably acted as a secondary gradient. We also examined size class distributions, age structures and growth rates of the three communities in order to describe community development and dynamics. Total tree density was 14700 plants/ha, with P. roxburghii having a relative density of 82%to 100%. Density of juve-nile and total density and basal area of the subordinate tree species were low. The low density of trees in the smallest diameter size-class sug-gested that the recruitment of small P. roxburghii plants into the adult population may be lower than the required replacement rate for the stands. Pooled size-class distributions for the species showed a multimo-dal pattern with some regeneration gaps. Browsing, heavy logging and＆amp;nbsp;other anthropogenic activities were the overriding factors responsible for the poor recruitment of P. roxburghii. We concluded from the age struc-ture that the forests were characterized by the dominance of young trees. Growth rate analysis revealed that P. roxburghii was the fastest growing species among the conifers species in Pakistan. In view of its relatively fast growth and longevity, P. roxburghii seems to be a suitable choice f

关键词： phytosociology structure dynamics multivariate techniques,dendrochronology Himalayan range

Cloning and expressional characterization of soybean GmLls1 gene

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Chinese Science Bulletin 2006年第10期51卷 1210-1218页

作者： LI Pengli MA Yuanyuan LI Xiaoping ZHANG Liwen WANG Yong WANG Ningning department of plant Biology and ecology Nankai University Tianjin300071 China

Maize Lls1 (lethal leaf-spot 1) gene and its Arabidopsis orthologue AtAcd1 have been sug-gested to encode pheide a oxygenase (PaO), a key enzyme catalyzing chlorophyll breakdown. To further elucidate the molecular mechanism that regulates chlorophyll catabolism during soybean leaf senes-cence, a soybean Lls1 homolog was cloned and designated as GmLls1 (GenBank Accession No. DQ154009). Database searches using the deduced protein sequence revealed that it was highly ho-mologous to Lls1 genes or Lls1 orthologues in Arabidopsis, maize, cowpea and tomato. Structural analysis of the predicted GmLLS1 protein revealed typical Rieske [2Fe-2S] and mononuclear iron-bind- ing domains as well as the C-terminus CxxC motif that were conserved in and featured PaO homo-logues. RT-PCR results showed that the transcription of GmLls1 was up-regulated in all the three tested senescence systems: the natural leaf senescence process, the dark-induced primary leaf senescence and senescing cotyledons. We have previously de-scribed the involvement of an LRR receptor-like kinase (RLK), RLPK2 in regulation of soybean leaf senescence. Here we report that the expression of GmLls1 gene was dramatically down-regulated by the RNAi-mediated suppression of rlpk2 and, as ex-pected, greatly up regulated by the CaMV 35S pro-moter derived overexpression of this RLK gene. These results suggested that the expression of GmLls1 was controlled by the RLPK2-mediated se-nescence signaling pathway. The observation that the detached rlpk2-RNAi transgenic leaves exhibitedlight-dependent necrotic lesions, which featured

关键词：大豆叶老化克隆 GmLlsl基因