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Uniqueness of the Gossypium mustelinum Genome Revealed by GISH and 45S rDNA FISH

Journal of Integrative Plant Biology 2013年第7期55卷 654-662页

作者： Qiong Wu Fang Liu Shaohui Li Guoli Song Chunying Wang Xiangdi Zhang Yuhong Wang David Stelly Kunbo Wang Cotton Research Institute the Chinese Academy of Agricultural Sciences/National Key Laboratory of Cotton Biology Haikou experimental station Chinese Academy of Tropical Agricultural Sciences Department of Soil and Crop Sciences Texas A&M UniversityCollege Station

Gossypium mustelinum （（AD）4） is one of five disomic species in Gossypium. Three 45S ribosomal DNA （rDNA） loci were detected in （AD）4 with 45S rDNA as probe, and three pairs of brighter signals were detected with genomic DNA （gDNA） of Gossypium D genome species as probes. The size and the location of these brighter signals were the same as those detected with 45S rDNA as probe, and were named GISH-NOR. One of them was super-major, which accounted for the fact that about one-half of its chromosome at metaphase was located at chromosome 3, and other two were minor and located at chromosomes 5 and 9, respectively. All GISH-NORs were located in A sub-genome chromosomes, separate from the other four allopolyploid cotton species. GISH-NOR were detected with D genome species as probe, but not A. The greatly abnormal sizes and sites of （AD）4 NORs or GISH-NORs indicate a possible mechanism for 45S rDNA diversification following （AD）4 speciation. Comparisons of GISH intensities and GISH-NOR production with gDNA probes between A and D genomes show that the better relationship of （AD）4 is with A genome. The shortest two chromosomes of A sub-genome of G. mustelinum were shorter than the longest chromosome of D sub-genome chromosomes. Therefore, the longest 13 chromosomes of tetraploid cotton being classified as A sub-genome, while the shorter 13 chromosomes being classified as D sub-genome in traditional cytogenetic and karyotype analyses may not be entirely correct.

关键词： Chromosomes cotton Gossypium mustelinum in situ hybridization nucleolar organizer region genome.

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Effects of Long-Term Winter Planted Green Manure on Distribution and Storage of Organic Carbon and Nitrogen in Water-Stable Aggregates of Reddish Paddy Soil Under a Double-Rice Cropping System

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Journal of Integrative Agriculture 2014年第8期13卷 1772-1781页

作者： YANG Zeng-ping ZHENG Sheng-xian NIE Jun LIAO Yu-lin XIE Jian Soil and Fertilizer Institute of Hunan Province Hunan Academy of Agricultural Sciences Scientifi c Observing and experimental station of Arable Land Conservation (Hunan) Ministry of Agriculture

In agricultural systems, maintenance of soil organic matter has long been recognized as a strategy to reduce soil degradation. Manure amendments and green manures are management practices that can increase some nutrient contents and improve soil aggregation. We investigated the effects of 28 yr of winter planted green manure on soil aggregate-size distribution and aggregateassociated carbon（C） and nitrogen（N）. The study was a randomized completed block design with three replicates. The treatments included rice-rice-fallow, rice-rice-rape, rice-rice-Chinese milk vetch and rice-rice-ryegrass. The experiment was established in 1982 on a silty light clayey paddy soil derived from Quaternary red clay（classified as Fe-Accumuli-Stagnic Anthrosols） with continuous early and late rice. In 2009, soil samples were collected（0-15 cm depth） from the field treatment plots and separated into water-stable aggregates of different sizes（i.e., 〉5, 2-5, 1-2, 0.5-1, 0.25-0.5 and 〈0.25 mm） by wet sieving. The long-term winter planted green manure significantly increased total C and N, and the formation of the 2-5-mm water-stable aggregate fraction. Compared with rice-rice-rape, rice-rice-Chinese milk vetch and rice-rice-ryegrass, the rice-rice-fallow significantly reduced 2-5-mm water-stable aggregates, with a significant redistribution of aggregates into micro-aggregates. Long-term winter planted green manure obviously improved C/N ratio and macro-aggregate-associated C and N. The highest contribution to soil fertility was from macro-aggregates of 2-5 mm in most cases.

关键词： green manure organic carbon reddish paddy soil total nitrogen water-stable aggregates

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Biological mechanisms driving the seasonal changes in the internal loading of phosphorus in shallow lakes

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Science China Earth Sciences 2006年第z1期49卷 14-27页

作者： XIE Ping Donghu experimental station of Lake Ecosystems State Key Laboratory of Freshwater Ecology and Biotechnology of ChinaInstitute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China

Because of the obvious importance of P as a nutrient that often accelerates growth of phytoplankton (including toxic cyanobacteria) and therefore worsens water quality, much interest has been devoted to P exchange across the sediment-water interface. Generally, the release mode of P from the sediment differed greatly between shallow and deep lakes, and much of the effort has been focused on iron and oxygen, and also on the relevant environmental factors, for example, turbulence and decomposition, but a large part of the P variation in shallow lakes remains unexplained. This paper reviews experimental and field studies on the mechanisms of P release from the sediment in the shallow temperate (in Europe) and subtropical (in the middle and lower reaches of the Yangtze River in China) lakes, and it is suggested that pH rather than DO might be more important in driving the seasonal dynamics of internal P loading in these shallow lakes, i.e., intense photosynthesis of phytoplankton increases pH of the lake water and thus may increase pH of the surface sediment,leading to enhanced release of P (especially iron-bound P) from the sediment. Based on the selective pump of P (but not N) from the sediment by algal blooms, it is concluded that photosynthesis which is closely related to eutrophication level is the driving force for the seasonal variation of internal P loading in shallow lakes. This is a new finding. Additionally, the selective pump of P from the sediment by algal blooms not only explains satisfactorily why both TP and PO4-P in the hypereutrophic Lake Donghu declined significantly since the mid-1980s when heavy cyanobacterial blooms were eliminated by the nontraditional biomanipulation (massive stocking of the filter-feeding silver and bighead carps), but also explains why TP in European lakes decreased remarkably in the spring clear-water phase with less phytoplankton during the seasonal succession of aquatic communities or when phytoplankton biomass was decreased

关键词： shallow lakes, internal P loading, algal blooms.

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Sap Flow of Populus euphratica in a Desert Riparian Forest in an Extreme Arid Region During the Growing Season

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Journal of Integrative Plant Biology 2007年第4期49卷 425-436页

作者： Jian-Hua Si Qi Feng Xiao-You Zhang Zong-Qiang Chang Yong-Hong Su Hai-Yang Xi Cold and Arid Region Environmental and Engineering Research Institute the Chinese Academy of Sciences Alashan Desert Eco-hydrology experimental Research station Lanzhou 730000 China

In the present study, the heat pulse technique was applied to investigate the stem sap flow of Populus euphratica in a desert riparian forest in an extreme arid region from April to October 2003 and from May to October 2004. The experimental sites were in Qidaoqiao （101 °10′ E, 41°59′ N） and Bayantaolai farm （101°14′ E, 42°01′ N） in Ejina county, in the low reaches of the Heihe River, China. The results indicated that the diurnal change in the velocity of sap flow showed minor fluctuations. At night, the rising of sap flow could be observed in the main tree species because of root pressure. During the growing season, the maximum average velocity was observed in July, followed by August, and the same velocity was observed in September and May; the minimum velocity was observed in October. The transpiration from June to August during the growing season accounted for approximately 70% of the annual total transpiration. The sap flow velocity of P. euphratica trees of different ages could be arranged in the order： 15 yr 〉 25 yr 〉 50 yr. Sap flow velocity was closely related to changes in micrometeorological factors, with average sap flow velocity showing a significant linear correlation with net radiation, air temperature and relative humidity.

关键词： desert riparian forest extreme arid region heat-pulse technique Populus euphratica sap flow velocity.

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experimental and numerical investigation of the flexural performance of channel steel-bolt joint for prefabricated subway stations

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 918-935页

作者： Lei WANG Shengyang ZHOU Xiangsheng CHEN Xian LIU Shuya LIU Dong SU Shouchao JIANG Qikai ZHU Haoyu YAO College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Key Laboratory of Coastal Urban Resilient Infrastructures(MOE) Shenzhen UniversityShenzhen 518061China Shenzhen Key Laboratory of Green Efficient and Intelligent Construction of Underground Metro StationShenzhen UniversityShenzhen 518061China College of Civil Engineering Tongji UniversityShanghai 200092China Shenzhen Municipal Design&Research Co. Ltd.Shenzhen 518029China Shenzhen Metro Group Co. Ltd.Shenzhen 518026China

Flexural performance of joints is critical for prefabricated *** study presents a novel channel steel-bolt(CB)joint for prefabricated subway ***-scale tests are carried out to investigate the flexural behavior of the CB joint under the design loads of the test-case *** addition,a three dimensional(3D)finite element(FE)model of the CB joint is established,incorporating viscous contact to simulate the bonding and detachment behaviors of the interface between channel steel and *** on the 3D FE model,the study examines the flexural bearing mechanism and influencing factors for the flexural performance of the CB *** results indicate that the flexural behavior of the CB joint exhibits significant nonlinear characteristics,which can be divided into four *** illustrate the piecewise linearity of the bending moment-rotational angle curve,a four-stage simplified model is proposed,which is easily applicable in engineering *** study reveals that axial force can enhance the flexural capacity of the CB joint,while the preload of the bolt has a negligible *** flexural capacity of the CB joint is approximate twice the value of the designed bending moment,demonstrating that the joint is suitable for the test-case station.

关键词： channel steel-bolt joint flexural performance full-scale test numerical simulation prefabricated subway station

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experimental and Modeling Study of Forest Fire Effect on Soil Thermal Conductivity

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Pedosphere 2016年第4期26卷 462-473页

作者： Kathleen M.SMITS Elizabeth KIRBY William J.MASSMAN Larry Scott BAGGETT Center for the experimental Study of Subsurface Environmental Processes Department of Civil and Environmental EngineeringColorado School of Mines USDA Forest Service Rocky Mountain Research Station

An understanding of soil thermal conductivity after a wildfire or controlled burn is important to land management and post-fire recovery efforts. Although soil thermal conductivity has been well studied for non-fire heated soils, comprehensive data that evaluate the long-term effect of extreme heating from a fire on the soil thermal conductivity are limited. The purpose of this study was to evaluate the long-term impact of fire on the effective thermal conductivity of soils by directly comparing fire-heated and no-fire control soils through a series of laboratory studies. The thermal conductivity was measured for ten soil samples from two sites within the Manitou experimental Forest, Colorado, USA, for a range of water contents from saturation to the residual degree of saturation. The thermal conductivity measured was compared with independent estimates made using three empirical models from literature, including the Campbell et al. （1994）, CSt~ and Konrad （2005）, and Massman et al. （2008） models. Results demonstrate that for the test soils studied, the thermal conductivity of the fire-heated soils was slightly lower than that of the control soils for all observed water contents. Modeling results show that the Campbell et al. （1994） model gave the best agreement over the full range of water contents when proper fitting parameters were employed. Further studies are needed to evaluate the significance of including the influence of fire burn on the thermal properties of soils in modeling studies.

关键词： controlled burn degree of saturation empirical model water content wildfire

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Spatiotemporal variations of internal P-loading and the related mechanisms in the large shallow Lake Chaohu

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Science China Earth Sciences 2006年第z1期49卷 72-81页

作者： ZHANG Min XIE Ping XU Jun LIU Bingqin YANG Hong Donghu Ecosystem experimental station of Lake Ecosystems State Key Laboratory of Freshwater Ecology and Biotechnology of ChinaInstitute of HydrobiologyChinese Academy of SciencesWuhan 430072China

Spatiotemporal variations of P species and adsorption behavior in water column,interstitial water,and sediments were investigated in the large shallow eutrophic Lake ***(Ortho-P)and total phosphorus(TP)concentrations were significantly higher in the western part than in the eastern part of the lake,due to different nutrient inputs from the surrounding ***,particulate phosphorus(PP)concentration was in a similar spatial pattern to Ortho-P and TP concentrations,and also showed significantly positive correlation with the biomass of Microcystis,indicating more uptake and store of phosphorus by Microcystis than by other *** of pH and intensive utilization of P by phytoplankton were the main factors promoting P(especially Fe-P)release from the sediment to interstitial water during the cyanobacterial blooms in Lake *** dynamics in TP concentration,P species and adsorption behavior of the sediment,coupled with the statistical analyses,suggested that the spatial heterogeneity of P contents in the sediment was influenced by various factors,*** activities,soil geochemistry and mineral *** spite of similar TP contents in the sediments,increase in proportion of Fe-P concentration in the sediment may result in a high risk of P release.

关键词： eutrophication water column sediment phosphorus species sorption and release Lake Chaohu cyanobacterial blooms.

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Gas exchange and water relations of young potted loquat *** under progressive drought conditions

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Journal of Integrative Agriculture 2018年第6期17卷 1360-1368页

作者： A.Stellfeldt M.A.Maldonado J.J.Hueso J.Cuevas Department of Agronomy University of AlmeriaceiA3 Almeria 04120Spain experimental station of Cajamar Las Palmerillas ceiA3 Almeria 04710Spain

Relationships between plant water status and gas exchange parameters at increasing levels of water stress were determined in Algerie loquats which grown in 50 I pots. Changes in soil water content and stem water potential and their effects on stomatal conductance （Gs ） and net photosynthesis （Pn） rate were followed in control plants and in plants without irrigation until the latter reached near permanent wilting point and some leaf abscission took place. Then, the irrigation was restarted and the comparison repeated. Soil water content and stem water potential gradually diminished in response to drought reaching the minimum values of 0.9 mm and -5.0 MPa, respectively, 9 days after watering suspension. Compromised plant water status had drastic effects on Gs values that dropped by 97％ in the last day of the drought period. Pn was diminished by 80％ at the end of the drought period. The increasing levels of water stress did not cause a steady increase in leaf temperature in non-irrigated plants. Non-irrigated plants wilted and lost some leaves due to the severity of the water stress. However, all non-irrigated plants survived and reached similar Pn than control plants just a week after the irrigation was restarted, confirming drought tolerance of loquat and suggesting that photosynthesis machinery remained intact.

关键词： Eriobotrya japonica deficit irrigation stem water potential net photosynthetic rate stomatal conductance

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Effects of gaps on regeneration of woody plants: a meta-analysis

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Journal of Forestry Research 2014年第3期25卷 501-510页

作者： Jiaojun Zhu Deliang Lu Weidong Zhang State Key Laboratory of Forest and Soil Ecology Qingyuan Experimental Station of Forest Ecology Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences

Forest gaps, openings in the canopy caused by death of one or more trees, have a profound effect on forest regeneration and drive the forest growth cycle. It is therefore necessary to understand the effects of forest gaps on regeneration for modern forest management. In order to provide a quantitative assessment of the effects of forest gaps on regen-eration of woody plants, we conducted this review of gap effects on woody plant regeneration on the basis of 527 observations from 42 indi-vidual papers, and reported the results of these data in a meta-analysis. Overall, densities of regenerated woody plants were significantly greater （359%） in forest gaps than on the closed-canopy forest floor. The regen-eration density in gaps of plantation forests was significantly greater （P＆lt;0.05） than that of natural forest because the regeneration in gaps of plan-tation forests was improved by both gap effects and experimental meas-ures. Similarly, in comparison to natural gaps, regeneration was better enhanced in artificial gaps. Regeneration density exhibited a significantly positive correlation with gap size, but a negative correlation with gap age because the gap size decreased with increasing gap age. Shade tolerance of woody plants affected regeneration density in gaps and understory. Average regeneration density of shade-tolerant species exhibited a sig-nificantly positive response to gaps but densities remained lower in total than those of intermediate and shade-intolerant species. Gap effects on regeneration decreased in response to increasing temperature and pre-cipitation because of the limiting effects of lower temperature and moisture on woody plant regeneration. In summary, forest gaps enhance woody plant regeneration, and the effects of gaps varied by forest type, gap characteristics, environmental factors and plant traits. The results of this meta-analysis are useful for better understanding the effects and roles of gaps on forest regeneration and forest manage

关键词： forest gap regeneration disturbance gap size gap age,shade tolerance

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Response of Pinus koraiensis seedling growth to different light conditions based on the assessment of photosynthesis in current and one-year-old needles

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Journal of Forestry Research 2014年第1期25卷 53-62页

作者： Jiaojun Zhu Kai Wang Yirong Sun Qiaoling Yan State Key Laboratory of Forest and Soil Ecology Qingyuan Experimental Station of Forest EcologyInstitute of Applied EcologyChinese Academy of Sciences University of Chinese Academy of Sciences

As one of the three major five-leaved pines in the northern hemisphere, Pinus koraiensis is the most important dominant tree species in the natural mixed-broadleaved Korean pine forests. However, the regeneration of P koraiensis under the canopy of secondary forest stands is poor because of the light limitation. This study was conducted to understand how P koraiensis seedlings adapt to different light intensities and what would be the optimum light level for their establishment and growth. Three repetition plots with four light intensities （15%, 30%, 60% and 100% of the natural incident irradiances, achieved by suspending layers of black nylon net above and surrounding the plots） were set up under natural climate conditions in a montane region in eastern Liaoning Province, Northeast China. A total of 80 P koraiensis seedlings with similar height and root collar diameter were transplanted into four plots. After one year of acclimation to the specific light conditions, the seasonal variations of the photosynthetic variables and needle traits of the current and one-year-old needles, and the growth parameters were observed under four light intensities. The results indicated that：（1） The seedling at 60% treatment exhibited the greatest growth, which agreed with the response of the light-saturated photosynthetic rates （Amax） and the dark respiration rate （Rd） in the current and one-year-old needles, i.e., Rd at 60% treatment was significantly lower than that at 100% treatment, but Amax did not differ between the seedlings at 100% and 60% treatments. （2） The P. koraiensis seedlings have a certain photosynthetic plasticity to adapt the light conditions by adjusting their needle traits and regulating the physiological processes, because Amax, Rd, light saturation point and compensation point, the needle mass area, needle nitrogen and chlorophyll contents were significantly （p〈0.05） correlated with the light intensities. Especially, Am,x at 100% and 60% treatments was signif

关键词： light requirement needle age needle trait photosynthetic plasticity Pinus koraiensis

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