分类： 生物学 >> 植物学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Savanna, semi-deserts, and hot deserts characterize the Saharo-Arabian region, which includes Morocco, Mauretania, Algeria, Tunisia, Libya, Egypt, Palestine, Kuwait, Saudi Arabia, Qatar, Bahrain, the United Arab Emirates, Oman, Yemen, southern Jordan, Syria, Iraq, Iran, Afghanistan, Pakistan, and northern India. Its neighboring regions, the Sudano-Zambezian region belonging to the Paleotropical Kingdom and the Mediterranean and Irano-Turanian regions included in the Holarctic Kingdom, share a large portion of their flora with the Saharo-Arabian region. Despite the widespread acknowledgment of the region's global importance for plant diversity, an up to date list of the Saharo-Arabian endemics is still unavailable. The available data are frequently insufficient or out of date at both the whole global and the national scales. Therefore, the present study aims at screening and verifying the Saharo-Arabian endemic plants and determining the phytogeographical distribution of these taxa in the Egyptian flora. Hence, a preliminary list of 429 Saharo-Arabian endemic plants in Egypt was compiled from the available literature. Indeed, by excluding the species that were recorded in any countries or regions outside the Saharo-Arabian region based on different literature, database reviews, and websites, the present study has reduced this number to 126 taxa belonging to 87 genera and 37 families. Regarding the national geographic distribution, South Sinai is the richest region with 83 endemic species compared with other eight phytogeographic regions in Egypt, followed by the Isthmic Desert (the middle of Sinai Peninsula, 53 taxa). Sahara regional subzone (SS1) distributes all the 126 endemic species, Arabian regional subzone (SS2) owns 79 taxa, and Nubo-Sindian subzone (SS3) distributes only 14 endemics. Seven groups were recognized at the fourth level of classification as a result of the application of the two-way indicator species analysis (TWINSPAN) to the Saharo-Arabian endemic species in Egypt, i.e., I Asphodelus refractus group, II Agathophora alopecuroides var. papillosa group, III Anvillea garcinii group, IV Reseda muricata group, V Agathophora alopecuroides var. alopecuroides group, VI Scrophularia deserti group, and VII Astragalus schimperi group. It's crucial to clearly define the Saharo-Arabian endemics and illustrate an updated verified database of these taxa for a given territory for providing future management plans that support the conservation and sustainable use of these valuable species under current thought-provoking devastating impacts of rapid anthropogenic and climate change in this region.
分类： 生物学 >> 植物学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： The presence of invasive plant species poses a substantial ecological impact, thus comprehensive evaluation of their potential range and risk under the influence of climate change is necessary. This study uses maximum entropy (MaxEnt) modeling to forecast the likelihood of Leucaena leucocephala (Lam.) de Wit invasion in Saudi Arabia under present and future climate change scenarios. Utilizing the MaxEnt modeling, we integrated climatic and soil data to predict habitat suitability for the invasive species. We conducted a detailed analysis of the distribution patterns of the species, using climate variables and ecological factors. We focused on the important influence of temperature seasonality, temperature annual range, and precipitation seasonality. The distribution modeling used robust measures of area under the curve (AUC) and receiver-operator characteristic (ROC) curves, to map the invasion extent, which has a high level of accuracy in identifying appropriate habitats. The complex interaction that influenced the invasion of L. leucocephala was highlighted by the environmental parameters using Jackknife test. Presently, the actual geographic area where L. leucocephala was found in Saudi Arabia was considerably smaller than the theoretical maximum range, suggesting that it had the capacity to expand further. The MaxEnt model exhibited excellent prediction accuracy and produced reliable results based on the data from the ROC curve. Precipitation and temperature were the primary factors influencing the potential distribution of L. leucocephala. Currently, an estimated area of 216,342 km2 in Saudi Arabia was at a high probability of invasion by L. leucocephala. We investigated the potential for increased invasion hazards in the future due to climate change scenarios (Shared Socioeconomic Pathways (SSPs) 245 and 585). The analysis of key climatic variables, including temperature seasonality and annual range, along with soil properties such as clay composition and nitrogen content, unveiled their substantial influence on the distribution dynamic of L. leucocephala. Our findings indicated a significant expansion of high risk zones. High-risk zones for L. leucocephala invasion in the current climate conditions had notable expansions projected under future climate scenarios, particularly evident in southern Makkah, Al Bahah, Madina, and Asir areas. The results, backed by thorough spatial studies, emphasize the need to reduce the possible ecological impacts of climate change on the spread of L. leucocephala. Moreover, the study provides valuable strategic insights for the management of invasion, highlighting the intricate relationship between climate change, habitat appropriateness, and the risks associated with invasive species. Proactive techniques are suggested to avoid and manage the spread of L. leucocephala, considering its high potential for future spread. This study enhances the overall comprehension of the dynamics of invasive species by combining modeling techniques with ecological knowledge. It also provides valuable information for decision-making to implement efficient conservation and management strategies in response to changing environmental conditions.
分类： 生物学 >> 植物学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Rising atmospheric CO2 (carbon dioxide) concentrations and salinization are manifestations of climate change that affect plant growth and productivity.Species with an intermediate C3-C4 type of photosynthesis live in a wide range of precipitation, temperature, and soil quality, but are more often found in warm and dry habitats. One of the intermediate C3-C4 photosynthetic type is C2 photosynthesis with a carbon concentration mechanism (CCM) that reassimilates CO2 released via photorespiration. However, the ecological significance under which C2 photosynthesis has advantages over C3 and C4 plants remains largely unexplored. Salt tolerance and functioning of CCM were studied in plants from two populations (P1 and P2) of Sedobassia sedoides (Pall.) Freitag G. Kadereit Asch. species with C2 photosynthesis exposed to 4 d and 10 d salinity (200 mM NaCl) at ambient (785.7 mg/m3, aCO2) and elevated (1571.4 mg/m3, eCO2) CO2. On the fourth day of salinity, an increase in Na+ content, activity catalase, and superoxide dismutase was observed in both populations. P2 plants showed an increase in proline content and a decrease in photosynthetic enzyme content: rubisco, phosphoenolpyruvate carboxylase (PEPC), and glycine decarboxylase (GDC), which indicated a weakening of C2 and C4 characteristics under salinity. Treatment under 10 d salinity led to an increased Na+ content and activity of cyclic electron flow around photosystem I (PSI CEF), a decreased content of K+ and GDC in both populations. P1 plants showed greater salt tolerance, which was assessed by the degree of reduction in photosynthetic enzyme content, PSI CEF activity, and changes in relative growth rate (RGR). Differences between populations were evident under the combination of eCO2 and salinity. Under long-term salinity and eCO2, more salt-tolerant P1 plants had a higher dry biomass (DW), which was positively correlated with PSI CEF activity. In less salt-tolerant P2 plants, DW correlated with transpiration and dark respiration. Thus, S. sedoidesshowed a high degree of photosynthetic plasticity under the influence of salinity and eCO2 through strengthening (P1 plants) and weakening C4characteristics (P2 plants).
分类： 生物学 >> 生态学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： The Keriya River Basin is located in an extremely arid climate zone on the southern edge of the Tarim Basin of Northwest China, exhibiting typical mountain-oasis-desert distribution characteristics. In recent decades, climate change and human activities have exerted significant impacts on the service functions of watershed ecosystems. However, the trade-offs and synergies between ecosystem services (ESs) have not been thoroughly examined. This study aims to reveal the spatiotemporal changes in ESs within the Keriya River Basin from 1995 to 2020 as well as the trade-offs and synergies between ESs. Leveraging the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and Revised Wind Erosion Equation (RWEQ) using land use/land cover (LULC), climate, vegetation, soil, and hydrological data, we quantified the spatiotemporal changes in the five principal ESs (carbon storage, water yield, food production, wind and sand prevention, and habitat quality) of the watershed from 1995 to 2020. Spearman correlation coefficients were used to analyze the trade-offs and synergies between ES pairs. The findings reveal that water yield, carbon storage, and habitat quality exhibited relatively high levels in the upstream, while food production and wind and sand prevention dominated the midstream and downstream, respectively. Furthermore, carbon storage, food production, wind and sand prevention, and habitat quality demonstrated an increase at the watershed scale while water yield exhibited a decline from 1995 to 2020. Specifically, carbon storage, wind and sand prevention, and habitat quality presented an upward trend in the upstream but downward trend in the midstream and downstream. Food production in the midstream showed a continuously increasing trend during the study period. Trade-off relationships were identified between water yield and wind and sand prevention, water yield and carbon storage, food production and water yield, and habitat quality and wind and sand prevention. Prominent temporal and spatial synergistic relationships were observed between different ESs, notably between carbon storage and habitat quality, carbon storage and food production, food production and wind and sand prevention, and food production and habitat quality. Water resources emerged as a decisive factor for the sustainable development of the basin, thus highlighting the intricate trade-offs and synergies between water yield and the other four services, particularly the relationship with food production, which warrants further attention. This research is of great significance for the protection and sustainable development of river basins in arid areas.
分类： 农、林、牧、渔 >> 土壤学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Soil salinization may affect biodiversity and species composition, leading to changes in the plant community structure. However, few studies have explored the spatial pattern of soil salinization and its effects on shrub community structure at the ecosystem scale. Therefore, we conducted a transect sampling of desert shrublands in Northwest China during the growing season (June–September) in 2021. Soil salinization (both the degree and type), shrub community structure (e.g., shrub density and height), and biodiversity parameters (e.g., Simpson diversity, Margalf abundance, Shannon-Wiener diversity, and Pielou evenness indices) were used to assess the effects of soil salinization on shrub community structure. The results showed that the primary degree of soil salinization in the study area was light salinization, with the area proportion of 69.8%. Whereas the main type of soil salinization was characterized as sulfate saline soil, also accounting for 69.8% of the total area. Notably, there was a significant reduction in the degree of soil salinization and a shift in the type of soil salinization from chloride saline soil to sulfate saline soil, with an increase in longitude. Regional mean annual precipitation (MAP), mean annual evapotranspiration (MAE), elevation, and slope significantly contributed to soil salinization and its geochemical differentiation. As soil salinization intensified, shrub community structure displayed increased diversity and evenness, as indicated by the increases in the Simpson diversity, Shannon-Wiener diversity, and Pielou evenness indices. Moreover, the succulent stems and leaves of Chenopodiaceae and Tamaricaceae exhibited clear advantages under these conditions. Furthermore, regional climate and topography, such as MAP, MAE, and elevation, had greater effects on the distribution of shrub plants than soil salinization. These results provide a reference for the origin and pattern of soil salinization in drylands and their effects on the community structure of halophyte shrub species.
分类： 农、林、牧、渔 >> 土壤学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Perennial grass-legume mixtures have been extensively used to restore degraded grasslands, increasing grassland productivity and forage quality. Tillage is crucial for seedbed preparation and sustainable weed management for the establishment of grass-legume mixtures. However, a common concern is that intensive tillage may alter soil characteristics, leading to losses in soil organic carbon (SOC). We investigated the plant community composition, SOC, soil microbial biomass carbon (MBC), soil enzyme activities, and soil properties in long-term perennial grass-legume mixtures under two different tillage intensities (once and twice) as well as in a fenced grassland (FG). The establishment of grass-legume mixtures increased plant species diversity and plant community coverage, compared with FG. Compared with once tilled grassland (OTG), twice tilled grassland (TTG) enhanced the coverage of high-quality leguminous forage species by 380.3%. Grass-legume mixtures with historical tillage decreased SOC and dissolved organic carbon (DOC) concentrations, whereas soil MBC concentrations in OTG and TTG increased by 16.0% and 16.4%, respectively, compared with FG. TTG significantly decreased the activity of N-acetyl-β-D-glucosaminidase (NAG) by 72.3%, whereas soil enzyme β-glucosidase (βG) in OTG and TTG increased by 55.9% and 27.3%, respectively, compared with FG. Correlation analysis indicated a close association of the increase in MBC and βG activities with the rapid decline in SOC. This result suggested that MBC was a key driving factor in soil carbon storage dynamics, potentially accelerating soil carbon cycling and facilitating biogeochemical cycling. The establishment of grass-legume mixtures effectively improves forage quality and boosts plant diversity, thereby facilitating the restoration of degraded grasslands. Although tillage assists in establishing legume-grass mixtures by controlling weeds, it accelerates microbial activity and organic carbon decomposition. Our findings provide a foundation for understanding the process and effectiveness of restoration management in degraded grasslands.
分类： 农、林、牧、渔 >> 土壤学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel, where gravel could affect the water movement process in the soil. This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil. The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment. Six experimental groups with gravel contents of 0%, 10%, 20%, 30%, 40%, and 50% were established to determine the saturated hydraulic conductivity (Ks), saturated water content (θs), initial water content (θi), and retention water content (θr), and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment. The Philip model was used to fit the soil absorption process and determine the soil water absorption rate. Then the length of the characteristic wetting front depth, shape coefficient, empirical parameter, inverse intake suction and soil water suction were derived from the van Genuchten model. Finally, the hydraulic parameters mentioned above were used to fit the soil water characteristic curves, unsaturated hydraulic conductivity (Kθ) and specific water capacity (C(h)). The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content. Compared with control check treatment with gravel content of 0%, soil water absorption rates in the treatments with gravel contents of 10%, 20%, 30%, 40%, and 50% decreased by 11.47%, 17.97%, 25.24%, 29.83%, and 42.45%, respectively. As the gravel content increased, inverse intake suction gradually increased, and shape coefficient, Ks, θs, and θr gradually decreased. For the same soil water content, soil water suction and Kθ gradually decreased with increasing gravel content. At the same soil water suction, C(h) decreased with increasing gravel content, and the water use efficiency worsened. Overall, the water holding capacity, hydraulic conductivity, and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content. This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas.
分类： 地球科学 >> 水文学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： Understanding the distribution and dynamics of glaciers is of great significance to the management and allocation of regional water resources and socio-economic development in arid regions of Northwest China. In this study, based on 36 Landsat images, we extracted the glacier boundaries in the Manas River Basin, Northwest China from 2000 to 2020 using eCognition combined with band operation, GIS (geographic information system) spatial overlay techniques, and manual visual interpretation. We further analyzed the distribution and variation characteristics of glacier area, and simulated glacial runoff using a distributed degree-day model to explore the regulation of runoff recharge. The results showed that glacier area in the Manas River Basin as a whole showed a downward trend over the past 21 a, with a decrease of 10.86% and an average change rate of –0.54%/a. With the increase in glacier scale, the number of smaller glaciers decreased exponentially, and the number and area of larger glaciers were relatively stable. Glacier area showed a normal distribution trend of increasing first and then decreasing with elevation. About 97.92% of glaciers were distributed at 3700–4800 m, and 48.11% of glaciers were observed on the northern and northeastern slopes. The retreat rate of glaciers was the fastest (68.82%) at elevations below 3800 m. There was a clear rise in elevation at the end of glaciers. Glaciers at different slope directions showed a rapid melting trend from the western slope to the southern slope then to the northern slope. Glacial runoff in the basin showed a fluctuating upward trend in the past 21 a, with an increase rate of 0.03×108 m3/a. The average annual glacial runoff was 4.80×108 m3, of which 33.31% was distributed in the ablation season (June–September). The average annual contribution rate of glacial meltwater to river runoff was 35.40%, and glacial runoff accounted for 45.37% of the total runoff during the ablation season. In addition, precipitation and glacial runoff had complementary regulation patterns for river runoff. The findings can provide a scientific basis for water resource management in the Manas River Basin and other similar arid inland river basins.
分类： 医学、药学 >> 预防医学与公共卫生学 提交时间： 2024-07-31 合作期刊: 《中国全科医学》
摘要： 背景 随着居民经济水平的提高及生活方式的改变，儿童青少年肥胖问题日益严峻，威胁着儿童青少年的健康成长，目前多数研究主要以BMI作为儿童青少年肥胖的评价指标，可能低估了儿童青少年中心性肥胖水平。因此，亟需评价儿童青少年中心性肥胖水平及变化趋势，为有针对性提出干预措施提供科学依据。目的 分析2018—2023年上海市普陀区7~18岁儿童青少年腰围水平及中心性肥胖率变化趋势。方法 利用 2018年、2020—2023年上海市普陀区中小学生健康体检数据，分析普陀区7~18岁儿童青少年腰围水平、中心性肥胖率及变化趋势。以不同性别儿童青少年年龄别第90百分位数（P90）作为儿童青少年高腰围界值点，将腰围超过同年龄同性别组的 P90 值定义为中心性肥胖。应用 SPSS 22.0、SAS 13.1 软件进行统计学分析、Excel 2021 进行图形绘制。结果 2018—2023 年参加上海市普陀区中小学生健康体检学生共 280 648 人次，其中男生 146 334 人次（52.1%），女生 134 314 人次（47.9%），平均年龄为（10.9±2.6）岁。2018—2023 年男女生腰围整体水平呈波动下降趋势，差异有统计学意义（H 男 =209.785、H 女 =373.076，P<0.001），男生由 2018 年的 65.2（58.0，74.0）cm 下降至 2023 年的 64.8（56.9，74.0）cm，女生由60.5（55.0，67.0）cm 下降至 59.8（53.8，66.2）cm。2018—2023 年男女生组各年份中心性肥胖率比较，差异均有统计学意义（χ2 男 =264.123、χ2 女 =448.289，P<0.001）；Cochran-Armitage 趋势检验结果显示，2018—2023 年男女生组中心性肥胖率整体呈下降趋势（Z 趋势男 =-10.974，Z 趋势女 =-15.218，P 趋势 <0.001）；男生中心性肥胖率由 2018 年的28.8% 下降至 2023 年的 24.6%，女生中心性肥胖率由 21.9% 下降至 15.5%。其中 2022 年男女生腰围水平及中心性肥胖率均有所升高。男女生中心性肥胖率随年龄增长呈上升趋势（Z 趋势男 =35.167，Z 趋势女 =6.533，P 趋势 <0.001）结论 本研究提示普陀区 7~18 岁儿童青少年腰围水平、中心性肥胖率呈波动下降趋势；男生腰围水平和中心性肥胖率较同年龄女生高；中心性肥胖率随年龄增长呈上升趋势，本研究结果为后续有针对性开展儿童青少年中心性肥胖干预工作提供了理论支持。
分类： 医学、药学 >> 预防医学与公共卫生学 提交时间： 2024-07-31 合作期刊: 《中国全科医学》
摘要： 背景随着人口老龄化，压力性损伤（PI）的发病率逐渐增加，这不仅严重影响了患者的生存质量，还增加了医保支出。然而，PI的早期发现和准确分期极大地依赖于专业培训。目的 构建并测试一个用于PI自动检测和分期的人工智能模型，目的是提高PI诊断的实时性、准确性和客观性。方法 从常熟市第一人民医院压疮电子化管理系统中选取了2021年1月—2024年2月期间的693张PI图片，并按照2019NPUAP指南分为6期，包括：Ⅰ期154张、Ⅱ期188张、Ⅲ期160张、Ⅳ期82张、不可分期52张、深部组织损伤期57张。利用基于5种不同版本大小的YOLOv8神经网络和迁移学习，建立针对PI的深度学习目标检测模型。模型评价指标包括精确度、准确率、灵敏度、特异度及检测速度等。最后，通过UltralyticsHub平台将模型部署到手机应用程序（App）中，实现AI模型在临床工作中的应用。结果 在对包含142张PI图像的测试集进行评估时，YOLOv8l版本在确保高精确度（0.827）的同时，也展现了较快的推理速度（68.49fps），与其他YOLO版本相比，在精确度与速度之间取得了最佳的平衡。具体而言，其在所有类别上的整体准确率为93.18%，灵敏度为76.52%，特异度为96.29%，假阳性率为3.72%。在6个PI分期中，模型对“Ⅰ期”的准确率最高，达到95.97%；Ⅱ期、Ⅲ期、Ⅳ期、深部组织损伤期、不可分期，分别取得了91.28%、91.28%、91.95%、95.30%和93.29%的准确率。就处理速度而言，平均每秒可处理68.49张PI图像。结论 基于YOLOv8l网络的AI模型能够快速、准确地检测和分期PI。将该模型部署到手机App中，能够在临床实践中便携使用，具有很大的临床应用潜力。
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2024-07-31 合作期刊: 《广西植物》
摘要： 新生小枝是植物分支系统中最活跃的部分，对光照、温度等生境变化的响应最为敏 感。分析植物新生小枝茎叶性状差异和评价其生长状况，对于理解植物的生长生存策略和 适应性机制极为关键。秋茄作为常绿阔叶小乔木，其冠层在一年内不同季节都会产生一定 数量新生小枝，为深入了解秋茄新生小枝生长状况及季节动态规律，该研究通过对新生小 枝茎叶生长性状的调查与测定，结合方差分析、多重比较和主成分分析等统计方法，综合 评价不同季节秋茄新生小枝生长表现，探究以秋茄为代表的红树植物生长生存策略。结果 表明：（1）表征秋茄新生小枝生长状况的14 个性状指标具有较大变异，变异系数处于 13.856%~56.469%，平均变异系数为35.627%；并且指标间具有较强相关性。（2）秋茄新生 小枝生长性状在不同季节存在显著差异（P5 月>3 月>10 月。（3） 秋茄新生小枝生长性状重要性排序为叶性状（55.050%）>生物量（35.480%）>茎构型 （9.470%）；叶密度、叶茎生物量比、叶数量、叶生物量、大叶面积、茎长、叶面积比7 个 性状指标总权重占比为87.146%，是表征秋茄新生小枝生长状况的关键指标。综上认为， 秋茄新生小枝生长状况反映了树体对资源水平的适应策略，外因光照和温度及内因生长策 略共同影响着新生小枝生长状况。该研究结果揭示了秋茄新生小枝对不同生长季节环境变 化的响应，为秋茄种群保护和可持续发展提供了参考依据。
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2024-07-31 合作期刊: 《广西植物》
摘要： 小麦是世界三大主粮之一，重要农艺性状的QTL 定位和候选基因分析有利于高产稳 产新品种培育。本研究选用小麦品种蜀麦969 与蜀麦830 构建了包含89 个株系的重组自交 系（F7）群体，利用简化基因组测序技术对重组自交系及其亲本进行了基因分型，结合农 艺性状表型数据，采用完备区间作图方法鉴定了控制株高、穗下节长、芒长、穗长、旗叶长、 旗叶宽、分蘖数、有效分蘖数和千粒重、粒长、粒宽、籽粒表面积的QTL 位点。结果表明： （1）鉴定到了27 个农艺性状相关的QTL，分布在13 个染色体上，可解释表型变异的 3.74%~26.7%。其中7B 染色体608.58～609.12 Mb 区间的QTL 位点同时控制株高和穗下节 长度，这一位点在2 个年份均检测到。5A 染色体519.94～528.83 Mb 区间的QTL 同时控制 分蘖数和有效分蘖数，而5D 染色体437.38～439.30 Mb 区间的QTL 同时控制千粒重和籽粒 表面积。7 个QTL 位点与前人报道的位置相同。（2）在QTL 定位区间开展功能基因预测， 成功预测2 个株高、4 个分蘖和3 个千粒重的候选基因。2 个株高候选基因分别是编码富含 亮氨酸重复序列受体样蛋白激酶家族蛋白和赤霉素2-氧化酶的基因。4 个分蘖候选基因分别 是编码生长素反应蛋白、RING/U-box 超家族蛋白和两个F-box 蛋白的基因。3 个千粒重候 选基因分别是编码富含亮氨酸重复序列受体样蛋白激酶家族蛋白、蛋白激酶家族蛋白和叶绿 素a-b 结合蛋白的基因。该研究鉴定的小麦重要农艺性状QTL 位点，为候选基因精细定位 及克隆提供依据,助力小麦新品种培育。
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2024-07-31 合作期刊: 《广西植物》
摘要： NAC 转录因子在植物生长发育和逆境胁迫中起着重要作用，然而，马缨杜鹃RdNAC72 基因是否参与调控高温胁迫响应的机制尚未见报道。为了研究RdNAC72 基因与高温胁迫的 相关性及其潜在的调控机制，该研究对马缨杜鹃RdNAC72 基因CDS 序列进行引物设计，通 过PCR 技术克隆RdNAC72 基因全长编码序列。通过生物信息学对基因的结构、功能和蛋白 理化性质等进行分析和预测，并利用实时荧光定量PCR（RT-qPCR）对该基因在高温胁迫下 的时空表达特征及在ABA 胁迫下的表达模式进行分析。结果表明：（1）该基因全长1 005 bp，编码334 个氨基酸，相对分子量为37.415 kDa。亚细胞定位显示RdNAC72 蛋白定位于 细胞核。（2）多序列比对及系统发育分析表明，RdNAC72 与圆叶杜鹃的RwNAC72 亲缘关 系最近，顺式作用元件分析发现该基因启动子区具有参与激素、光响应、厌氧响应、低温和 热应激响应元件。（3）高温胁迫可诱导RdNAC72 表达且具有时空表达特异性，高温胁迫 处理3 d 时叶片中的RdNAC72 相对表达量显著上调了31.16 倍，但茎和根中该基因没有显 著变化，高温胁迫处理6 d 时，根、茎、叶中的RdNAC72 相对表达量均显著上调，其中叶 片最高，显著上调了61.56 倍，其次是茎，显著上调了50.14 倍，根中则显著上调了17.42 倍；此外，还发现ABA 可诱导RdNAC72 表达。（4）RT-qPCR 结果显示RdHSP17.2 与RdNAC72 基因有协同的表达模式，且RdHSP17.2 启动子区含有多个NAC 识别基序CATGTG 和核心 结合序列CACG，推测RdHSP17.2 可能是RdNAC72 的下游靶基因。该研究丰富了逆境胁迫 下NAC 转录因子的生物学功能，并可为今后该植物的遗传育种提供依据。
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2024-07-31 合作期刊: 《广西植物》
摘要： 为了研究广藿香（Pogostemon cablin）叶绿体基因组的结构特征，比较不同来源广藿香叶 绿体基因组的差异，该研究利用DNBSeq 测序平台对广藿香全基因组进行测序，使用getOrganelle 组装完整的广藿香叶绿体基因组，通过CPGAVAS2 网站对该叶绿体基因组进行注释，对不同来源 的广藿香叶绿体基因组进行基本结构特征分析、IR/SC 的边界比较、基因组比较及共线性分析、 简单重复序列及散在重复序列、多态性分析和同义密码子相对使用度分析。结果表明：（1）20 个不同来源广藿香叶绿体基因组全长152 461~152 510 bp，注释得到132 个基因，其中包含87 个 CDS，37 个tRNA 基因和8 个rRNA 基因。（2）mVISTA 比对发现atpF、atpF-atpH、rps16-trnQ_UUG、 rpoB-trnC_GCA、accD、psaI-ycf4、petA-psbJ、rpl16、rps15-ycf1 为高变区。（3）核酸多样性大 于0.002 的位点位于trnM-CAU-atpB 间隔区、ycf4、rpl32、rpl32-trnL-UAC 间隔区。（4）检测到 共有64 种密码子编码20 个氨基酸，偏好性较强的密码子有33 个，其中以A/U 结尾的密码子占 大多数。（5）检测出74~76 个SSR 及15~18 个回文重复序列、12~17 个正向重复序列。（6）经 遗传距离分析与系统发育分析，仅GSY_MLXY 与其他栽培类型的亲缘关系较远。该研究获得了 20 个不同来源广藿香叶绿体基因组结构信息以及差异位点，为分子标记的开发及优良种质筛选提 供基础资料。
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2024-07-31 合作期刊: 《广西植物》
摘要： 为了解喀斯特地区土地利用类型和水热条件影响土壤无机磷和生物有效磷组分的特征，该文分析比 较了低水热地区重庆南川区、贵州独山县和绥阳县以及高水热地区广西环江县、马山县/武鸣县和龙州县的 喀斯特地区耕地、人工林和天然林土壤无机磷和生物有效磷组分的变化特征。采用单因素方差分析、双因 素方差分析和相关性分析，探讨土地利用类型和水热条件影响下土壤无机磷组分和生物有效磷组分的差异 特征以及两者之间的关系，采用冗余分析探究影响土壤生物有效磷组分的关键无机磷组分。结果显示：（1） 土壤无机磷组分受土地利用类型显著影响，耕地土壤中磷酸二钙（Ca2-P）、磷酸八钙（Ca8-P）、铝结合态 磷（Al-P）、铁结合态磷（Fe-P）、闭蓄态磷（O-P）和磷酸十钙（Ca10-P）含量均高于人工林和天然林土 壤。Ca8-P、Fe-P 和O-P 含量表现为耕地>人工林>天然林，Ca2-P 和盐酸磷（HCl-P）含量则表现为耕地> 天然林>人工林；（2）在高水热地区，天然林土壤Ca10-P 和O-P 含量显著高于低水热地区，人工林和天然 林土壤的酶提取磷（Enzyme-P）含量则与之相反；（3）土壤无机磷组分Ca2-P、Ca8-P、Al-P、Fe-P 和Ca10-P 含量与生物有效磷组分CaCl2-P 和HCl-P 含量呈显著正相关，冗余分析表明，Ca2-P 是影响生物有效磷组分 的关键因子。上述结果表明，土地利用类型和水热条件是影响土壤无机磷组分及生物有效磷组分特征的关 键因素，无机磷组分含量的提高对生物有效磷组分具有正向作用。因此，应考虑未来气候变化可能对土壤 中磷的形态及其有效性产生的影响，以推进喀斯特生态系统恢复。
分类： 生物学 >> 植物学 >> 应用植物学 提交时间： 2024-07-31 合作期刊: 《广西植物》
摘要： 为探究鼓槌石斛(Dendrobium chrysotoxum)开花时挥发性成分特点及释放规律，本研究 采用固相微萃取(SPME)结合GC-MS技术检测鼓槌石斛花蕾期、初花期、盛花期和末花期4 个时期及盛花期唇瓣、萼片、花瓣和花蕊柱4 个部位的挥发性成分，并在此基础上进行主成 分、香气释放规律分析。结果表明：（1）鼓槌石斛4 个时期共检测挥发性成分29 种，由 13 种烯类、6 种醇类、2 种醛类、2 种酯类、2 种烷类、1 种酚类、1 种酸类和1 种其他类组 成，在鼓槌石斛盛花期4 个部位中共检测挥发性成分39 种，由15 种烯类、9 种醇类、4 种 烷类、3 种酯类、3 种酮类、2 种醛类、2 种其他类和1 种酸类组成。（2）在鼓槌石斛中挥 发性成分种类及含量在花朵盛开到衰败的整个过程中先逐渐升高而后降低，在盛花期挥发性 成分最多有22 种，主要为烯类和酯类。（3）醋酸辛酯、罗勒烯、(+)-α-蒎烯、(-)-β-蒎烯、 月桂烯、d-柠檬烯和正辛醇这7 种成分为鼓槌石斛中重要的挥发性成分，其中醋酸辛酯和罗 勒烯在盛花期中释放量最高，分别占总含量的31.74%和24.98%，醋酸辛酯在花蕾、初花、 盛花三个时期中都检测到且含量都较高，(+)-α-蒎烯、(-)-β-蒎烯、月桂烯、d-柠檬烯和正辛 醇这5 种挥发性成分仅在初花期和盛花期中检测到且随着花朵开放含量逐渐增加。（4）鼓 槌石斛不同部位释放的挥发性成分种类和含量存在差异，主要释香部位为花瓣和萼片，在萼 片中检测到的挥发性成分种类最多为29 种，在花瓣中检测到的挥发性成分种类有20 种，总 含量最高，为5 754.26 ng·g-1。综上表明，鼓槌石斛不同时期和不同部位释放的花香物质存 在差异，该研究结果为鼓槌石斛花日化产业开发奠定了理论基础。
分类： 心理学 提交时间： 2024-07-30
摘要： 基于动态发展视角和多基因研究范式，对1044名青少年（初测年龄13.32 ± 0.48岁, 50.1%女生）进行为期三年的追踪，考察青少年早期同伴拒绝的发展变化与亲社会行为发展变化的关系以及多巴胺系统基因的调节作用。结果发现：（1）青少年早期亲社会行为和同伴拒绝均呈线性上升趋势；（2）同伴拒绝的初始水平与增长速度均能预测亲社会行为发展轨迹。较高的同伴拒绝初始水平与较低的亲社会行为初始水平有关，也与更快的亲社会行为上升趋势有关，但是较高的同伴拒绝增长速度降低了亲社会行为的增长速度；（3）多巴胺系统多基因累加分调节同伴拒绝初始水平与亲社会行为初始水平、增长速度间的关系。相比携带较多高多巴胺含量相关等位基因的青少年，携带较少高多巴胺含量相关等位基因的青少年同伴拒绝初始水平越高，其亲社会行为初始水平更低、增长速度更快。
分类： 地球科学 >> 地理学 提交时间： 2024-07-30 合作期刊: 《干旱区地理》
摘要： 物流企业的空间布局不仅可以改变现有的物流组织形式，对重塑地区的产业空间格局也会产生重大影响。基于2006—2022年乌鲁木齐市物流企业空间数据，在对乌鲁木齐市物流企业区位时空演变分析的基础上，运用地理探测器和多尺度地理加权回归进一步探究物流企业区位选择的影响因素及其空间异质性，并提出优化物流企业空间布局的发展策略。结果表明：（1）乌鲁木齐市物流企业存在集聚分布特征，呈现出由“一主轴、一核心”向“三主核、两副核”演变的空间格局。（2）乌鲁木齐市地区间物流企业发展存在显著的正向溢出效应。（3）物流企业区位选择的影响因素中，物流企业数解释力度的均值为66%、地区GDP为48%、人口密度为49%、物流园区距离为28%；其中物流企业数和物流园区距离是空间异质性因素且其系数在空间上变化较大，地区GDP是具有正向影响的全局变量，人口密度是具有负向影响的全局变量。研究结果不仅拓展了企业区位理论的研究，而且丰富了研究案例，同时可以为乌鲁木齐市进行物流产业规划和高质量建设丝绸之路经济带商贸物流中心提供理论依据和实践参考。
分类： 地球科学 >> 地理学 提交时间： 2024-07-30 合作期刊: 《干旱区地理》
摘要： 银川市作为黄河流域重要的水源涵养区及国家重点生态功能区，其生境质量关乎区域生态安全和可持续发展。然而，针对银川市生境质量及其影响因子仍需深入研究。基于2000、2010年和2020年3期土地利用数据，耦合InVEST和Geodetector模型估算银川市20 a间生境质量，对研究区生境质量空间分布特征及影响因子进行分析。结果表明：（1）2000、2010年和2020年银川市平均生境质量指数分别为0.337、0.332和0.322，生境质量指数较低且20 a间略有下降，生境质量整体呈“南北高、中部低”的空间分布特征。（2）银川市生境质量在空间上存在着较强的空间集聚效应，莫兰指数呈下降趋势，集聚程度逐渐下降。（3）高程和土地利用类型是银川市生境质量的主要影响因子。各影响因子交互作用都存在增强效应，对生境质量的影响力随之增强，且以双因子增强为主，其次为非线性增强，其中高程与各因子的交互作用最为显著。研究结果可为银川市生态保护与高质量、可持续发展提供科学依据和决策支持。
分类： 地球科学 >> 地理学 提交时间： 2024-07-30 合作期刊: 《干旱区地理》
摘要： 通过对农业面源污染、农业净碳汇等变量测算构建指标体系，采用超效率SBM 模型、Malmquist指数模型方法计算2011—2020年新疆14个行政区农业水资源绿色效率值及其分解指数值，绘制标准差椭圆并构建马尔科夫链概率矩阵分析其空间格局变化，并用Tobit模型分析其影响因素。结果表明：（1）新疆各地州研究期内农业水资源绿色效率均值为0.865；各地区农业水资源绿色效率水平、提升效果及速度存在明显差异。（2）研究期内重心坐标始终在巴音郭楞蒙古自治州和静县巴音布鲁克镇内移动，先向东北移动后西南最终又向东北方向折回；较低、较高、高效率类型地区之间具有相互转移或跨类型转移的概率，低效率地区难以快速或跨类型增长。（3）经济发展水平、农业经济、供水结构对农业水资源绿色效率有显著的正向影响，资源禀赋与节水设施对农业水资源效率有显著的负向影响。研究结果对新疆农业水资源可持续利用、建设绿色高效农业具有重要的现实意义。
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