Leaf hydraulics coordinated with leaf economics and leaf size in mangrove species along a salinity gradient

Independence among leaf economics,leaf hydraulics and leaf size confers plants great capability in adapting to heterogeneous environments.However,it remains unclear whether the independence of the leaf traits revealed across species still holds within species,especially under stressed conditions.Here,a suite of traits in these dimensions were measured in leaves and roots of a typical mangrove species,Ceriops tagal,which grows in habitats with a similar sunny and hot environment but different soil salinity in southern China.Compared with C.tagal under low soil salinity,C.tagal under high soil salinity had lower photosynthetic capacity,as indicated directly by a lower leaf nitrogen concentration and higher water use efficiency,and indirectly by a higher investment in defense function and thinner palisade tissue;had lower water transport capacity,as evidenced by thinner leaf minor veins and thinner root vessels;and also had much smaller single leaf area.Leaf economics,hydraulics and leaf size of the mangrove species appear to be coordinated as one trait dimension,which likely stemmed from covariation of soil water and nutrient availability along the salinity gradient.The intraspecific leaf trait relationship under a stressful environment is insightful for our understanding of plant adaption to the multifarious environments.

Size-and leaf age-dependent effects on the photosynthetic and physiological responses of Artemisia ordosica to drought stress

Drought is one of the most significant natural disasters in the arid and semi-arid areas of China.Populations or plant organs often differ in their responses to drought and other adversities at different growth stages.At present,little is known about the size-and leaf age-dependent differences in the mechanisms of shrub-related drought resistance in the deserts of China.Here,we evaluated the photosynthetic and physiological responses of Artemisia ordosica Krasch.to drought stress using a field experiment in Mu Us Sandy Land,Ningxia Hui Autonomous Region,China in 2018.Rainfall was manipulated by installing outdoor shelters,with four rainfall treatments applied to 12 plots(5 m×5 m).There were four rainfall levels,including a control and rainfall reductions of 30%,50%and 70%,each with three replications.Taking individual crown size as the dividing basis,we measured the responses of A.ordosica photosynthetic and physiological responses to drought at different growth stages,i.e.,large-sized(>0.5 m^(2))and small-sized(≤0.5 m^(2))plants.The leaves of A.ordosica were divided into old leaves and young leaves for separate measurement.Results showed that:(1)under drought stress,the transfer efficiency of light energy captured by antenna pigments to the photosystem II(PSII)reaction center decreased,and the heat dissipation capacity increased simultaneously.To resist the photosynthetic system damage caused by drought,A.ordosica enhanced its free radical scavenging capacity by activating its antioxidant enzyme system;and(2)growth stage and leaf age had effects on the reaction of the photosynthetic system to drought.Small A.ordosica plants could not withstand severe drought stress(70%rainfall reduction),whereas large A.ordosica individuals could absorb deep soil water to ensure their survival in severe drought stressed condition.Under 30%and 50%rainfall reduction conditions,young leaves had a greater ability to resist drought than old leaves,whereas the latter were more resistant to severe drought stress.The response of A.ordosica photosynthetic system reflected the trade-off at different growth stages and leaf ages of photosynthetic production under different degrees of drought.This study provides a more comprehensive and systematic perspective for understanding the drought resistance mechanisms of desert plants.

Both small and large plants are likely to produce staminate(male)flowers in a hermaphrodite lily

Resource allocation to female and male function may vary among individual plants in species with variable sex expression.Size-dependent sex allocation has been proposed in hermaphrodites,in which female-biased allocation may increase with plant size.In many hermaphrodites with large floral displays,however,later-produced flowers tend to be functionally male.This paradoxical relationship between female and male function and plant size remains poorly understood.The subalpine lily Lilium lankongense has individuals of three sexual types:males with only staminate flowers,hermaphrodites with only perfect flowers,and andromonoecious plants with both perfect and staminate flowers.Here we tested theoretical predictions of size-dependent sex allocation in L.lankongense by measuring plant height and flower number of individuals of each sex at five field sites in the mountainous region of Shangri-La,southwestern China.To investigate variation in phenotypic gender,we identified sex expression of 457 individuals one year later.Our investigation showed that male plants,which usually produced one flower,were significantly smaller than and ro monoecious and hermaphrodite plants.In addition,the total flower numbers of andromonoecious and hermaphrodite plants increased significantly with plant size.Large individuals were more likely to produce terminal staminate flowers,as there were more flowers in andromonoecious than in hermaphrodite individuals.Non-flowered plants were significantly smaller than flowering ones.Perfect flowers had significantly larger petals and pistils than staminate flowers,but they did not differ in dry weight of stamens.Our findings indicate that when plants are small,the less costly sex is favored,consistent with the‘size-advantage hypothesis’.When plants are large,both female and male investments change isometrically,as later-produced flowers tend to be functionally male.

Variations in nitrogen isotopic values among various particle-sized fractions in modern soil in northwestern China

Ratios of stable nitrogen isotopes in organic matter derived from plants and preserved in soil are potential tracers for nitrogen cycles in natural ecosystems and valuable for evaluation of climate change. However, the rela-tionship between nitrogen isotopic compositions in surface soil and in plant litter during the decomposition process from plant litter to soil organic matter is not well understood. By using nitrogen isotopic analysis of soil parti-cle-sized fractions, nitrogen isotope discrimination between plant litter and surface soil organic matter in various modern ecosystems in northwestern China was conducted. The results of our study indicate that: (1) in general, the nitrogen isotopic compositions of particle-sized fractions from surface soil are different, and δ15N values increase from plant litter to fine soil organic matter; (2) the δ15N values in the soil particle-sized fractions become larger with increasing relative humidity and temperature, and the largest variation in the δ15N values is from -5.9‰ to -0.3‰; and (3) under a controlled climate, significant nitrogen isotope differences in δ15N values (Δδ15Nplant-soil) between plant litter and bulk soil organic matter were observed, with the values of 1.52 to 4.75 at various sites. Our results suggested that comparisons of Δδ15N values between bulk soil and the particle-sized fractions of soil could reveal the effect of humidity on transferring process of nitrogen from plant to soil in arid and semi-arid ecosystems.

OstMAPKKK5, a truncated mitogen-activated protein kinase kinase kinase 5, positively regulates plant height and yield in rice

Rice(Oryza sativa L.)is a major food crop worldwide.Plant height and yield are important agronomic traits of rice.Several genes regulating plant height and/or yield have been cloned.However,the molecular mechanisms coordinating plant height and yield are not fully characterized.Here,we report a novel gene,OstMAPKKK5 that encodes a truncated variant of a mitogen-activated protein kinase kinase kinase 5(OsMAPKKK5)lacking an intact kinase domain.Transgenic plants overexpressing OstMAPKKK5 in indica cultivar 9311 showed increased plant height,grain length,grain width,1000-grain weight,grain number per main panicle,and yield.Real-time quantitative PCR showed that OstMAPKKK5 was widely expressed in various tissues and developmental stages.The increased plant height and yield were attributed to enlarged cell size.Overexpression of OstMAPKKK5 led to higher contents of various forms of endogenous gibberellin(GA),especially the most common active forms,GA1,GA3,GA4.We concluded that OstMAPKKK5 positively regulates plant height and yield in rice by affecting cell size,and that its underlying mechanism is based on increased endogenous GA content.

The effects of fresh and rapid desiccated tissue on estimates of Ophiopogoneae genome size

Fresh plant material is usually used for genome size estimation by flow cytometry(FCM). Lack of fresh material is cited as one of the main reasons for the dearth of studies on plants from remote locations.Genome sizes in fresh versus desiccated tissue of 16 Ophiopogoneae species and five model plant species were estimated. Our results indicated that desiccated tissue was suitable for genome size estimation; this method enables broader geographic sampling of plants when fresh tissue collection is not feasible. To be useful, after dessication the Ophiopogoneae sample should be green without brown or yellow markings;it should be stored in deep freezer at à80C, and the storage time should be no more than 6 months.

基于神经辐射场的RGB图像点云重建多肉植物及尺寸测量研究

以多肉植物盆栽为研究对象,使用手持式RGB相机采集11个多肉植物盆栽的视频数据,通过将视频转换为图像帧、选取优质清晰图像帧、计算相机位姿得到含丰富信息的RGB图像数据。提出一种改进神经辐射场的多肉植物三维重建方法,根据实际场景提出新的射线采样策略,同时引入改进的图像修复模块与隐式模型重建点云方法,并根据点云重建结果提取多肉植株的叶片数、株高、冠围、凸包体积、叶长、叶宽和叶色共7个表型参数。最后选取具有代表性、易测量的叶片数、株高、冠围、叶长和叶宽5个表型参数进行精度评估与误差原因分析,平均绝对百分比误差(MAPE)分别为2.32%、3.95%、4.95%、5.59%和9.55%,均方根误差(RMSE)分别为0.86片和1.95、17.54、1.87、1.27 mm,决定系数(R^(2))分别为0.99、0.99、0.86、0.91和0.89。精度评估结果表明,所提取的表型参数能够准确、高效地反映多肉植株生长状态,充分发挥RGB图像新视角合成技术、图像处理技术与三维点云重建技术的优势,实现多肉植株盆栽的表型参数高精度、非破坏性提取,能够为多肉植物的种植和养育以及为非固定、多视角的RGB数据获取研究提供重要的技术支持。

栽培措施对西瓜果实大小的影响

为研究栽培措施对西瓜果实大小的影响,以“苏蜜518”为试材,“8424”为对照,采用不同整蔓方式结合不同坐瓜数以及不同整蔓方式结合不同种植密度2种处理方式,调查不同处理下果实重量、纵横径、果皮厚度、心糖、边糖等性状。结果发现,采用4蔓留不同坐瓜数试验无法获得预期结果,每株只能坐瓜2个,且果实重量差异显著。“苏蜜518”的小瓜重量为2.09~2.54 kg,“8424”的小瓜重量为2.24~2.54 kg。采用高密度栽培可以有效控制西瓜果重;高密度栽培结合整蔓留2个瓜,大小瓜差异显著,小瓜与大瓜相比,皮薄,中心糖略低,边糖差异不大。3蔓2瓜,株距30 cm,可以把小瓜重控制在2 kg以内。该研究探索了通过栽培措施调控西瓜果实大小的可行性,对生产中调控西瓜果实大小和产量有一定的应用价值。

表达SmERF1调节烟草种子大小及耐盐性

【目的】ERF转录因子生物功能广泛,在调控植物生长发育和响应胁迫中发挥重要作用。前期研究显示,丹参SmERF1参与植物响应胁迫反应。该研究旨在进一步明确SmERF1潜在的生物功能,并为药用植物抗性及种子发育研究奠定基础。【方法】该研究采用农杆菌介导的方法在模式植物烟草中异源表达了丹参SmERF1基因;通过抗性相关酶活性变化检测,对转基因植株抗性进行评价;通过酶联免疫方法和qPCR方法分析GA和ABA等激素含量及合成途径关键酶基因的表达变化。【结果】(1)表达SmERF1的烟草植株在幼苗期表现出生长缓慢、生物量和叶绿素减少,而在其他生长阶段与对照植株没有明显差异;此外,表达SmERF1的烟草植株种子比野生对照的种子小、轻;(2)在盐处理下,转基因烟草株系中脯氨酸含量、SOD和POD活性高于对照株系,而MDA含量低于对照株系,转基因烟草株系表现出较高的耐盐性;(3)在转烟草株系中,ABA含量上调,GA水平降低。实时定量PCR结果显示,表达SmERF1调节了与植物激素生物合成相关的关键酶基因的表达,如NtSDR、NtGA20ox、NtACO和NtACS。【结论】SmERF1通过ABA依赖途径增强了烟草对盐胁迫的耐受性,并调控种子大小。

稀缺主焦煤高效重介分选工艺在吕家坨矿选煤厂的应用

针对吕家坨矿选煤厂原生产工艺存在的问题,分析了入选原煤煤质特性,采用超宽粒级原煤三产品重介质旋流器选煤工艺、新型煤泥重介质旋流器选煤技术-反分流分选工艺、粗精煤泥两段弧形筛组合脱泥回收技术进行技术改造。改造后工艺系统指标检测结果表明,改造可提高综合精煤产率1.78%,增加税前利润10573.2万元。

种植密度对沿淮玉米籽粒淀粉粒度分布与糊化特性的影响

分析不同种植密度对沿淮玉米籽粒中淀粉粒度分布与糊化特性的影响。以豫单132、京科968等13个玉米杂交品种为材料,设置56 250株/hm^(2)、67 500株/hm^(2)、77 250株/hm^(2)等3个种植密度,分析不同种植密度对玉米籽粒品质、淀粉粒度分布与糊化特性的影响。结果表明,在种植密度56 250~77250株/hm^(2)范围内,随着种植密度的增加,玉米籽粒的蛋白质和脂肪含量呈递减趋势,淀粉含量呈递增趋势,即淀粉/蛋白质比率增加。玉米籽粒大型淀粉粒体积和表面积百分比显著增加,小型淀粉粒却显著降低。增加种植密度后玉米淀粉的峰值黏度、低谷黏度、最终黏度和稀懈值等黏度参数均呈显著升高。相关分析表明,玉米籽粒峰值黏度等黏度参数与小、大型淀粉粒体积百分比呈正相关,与中型淀粉粒体积百分比呈显著或极显著负相关。说明种植密度影响玉米籽粒淀粉粒度分布、淀粉黏度参数和组分含量。

植物纤维拆解及自成型技术研究进展

植物纤维属于植物的厚壁组织,植物纤维的利用对我国减少碳排放,实现碳中和目标具有重要意义。植物纤维是一种具备高长径比,能够自交织成型的生物质材料,将其加工成纤维制品,可以减轻对石油基等不可再生资源的依赖。重点介绍了化学拆解、物理拆解和生物拆解获得不同尺度植物纤维的机理、优缺点,并且对拆解后不同尺度的植物纤维所需的成型工艺和发展趋势进行了综述。未来需要在木质素高效拆解的基础上,开发不同尺度纤维的高效成型技术,使预处理和成型工艺更加低碳环保,提高植物纤维制品的应用效果和使用性能。

湖北南河国家级自然保护区及周边七子花群落特征与种群结构

七子花(Heptacodium miconioides Rehder)为我国特有的落叶灌木或小乔木,被列入国家重点保护野生植物名录和世界自然保护联盟(IUCN)受威胁植物名录。2022年8月,被认为在湖北消失115年的七子花,在谷城南河国家级自然保护区及其周边被重新发现。本研究以新发现的3个七子花种群(傅家寨、玉皇阁和李庙镇)为研究对象,分析其生境特征、伴生群落物种组成、种群结构和受威胁因素。分布区的植被为典型的落叶阔叶林,以小叶鹅耳枥(Carpinus stipulata H.J.P.Winkl.)、化香树(Platycarya strobilacea Siebold&Zucc.)、七子花和栓皮栎(Quercus variabilis Blume)为优势种。新发现种群共记录到151株七子花,基本都分布于海拔1000~1300 m的山脊或崖壁上。七子花的大小级结构图呈纺锤型,表明新发现种群为衰退型,实生苗更新不足。新发现的151株个体中有137株(91%)产生萌蘖,共产生936个萌蘖,平均每株6.83个。大量的萌蘖在很大程度上弥补了幼苗的不足,使该物种能够占领其生态位,利于种群的维持。新发现种群位于偏远山区的山脊和崖壁上,人为干扰较小,因此可以推测内因是其种群衰退的主要驱动力。建议对周边区域开展更大规模的调查,同时采用包括就地保护、人工扩繁、迁地保护和野外回归在内的整合保护计划加强对七子花的保护和可持续利用。

农田排水沟植物配置对底泥粒度特征及碳氮磷去除效果的影响

控制和降低农田退水污染物浓度是防治灌区及水体富营养化的关键。农田排水沟是农田退水流经的首个场所,为了探究植物配置对农田排水沟底泥粒度特征及碳氮磷去除效果的影响,在宁夏引黄灌区3条独立的农田排水沟:芦苇(Phragmites australis)模式(沟-1),芦苇+香蒲(Typha orientalis)模式(沟-2),芦苇+香蒲+睡莲(Nymphaea tetragona)、狐尾藻(Myriophyllum verticillatum)、水葱(Scirpus validus)模式(沟-3)采集0-20 cm底泥,测定底泥颗粒组成、粒度参数及碳氮磷含量。结果表明:3条排水沟底泥属于粉砂壤土,以粉粒为主,黏粒占比最低,平均粒级为5.20-6.07Φ;分选性较差,偏度为近对称和正偏,峰度为中等和尖窄,分形维数为2.19-2.63,质地偏粗;随植物种类和覆盖度增加,底泥粉粒、黏粒体积分数显著增加,砂粒体积分数显著下降,粒度参数显著增大;沟-1、沟-2底泥粒度频率曲线呈单峰分布,沟-3呈双峰分布,粒度概率累积曲线以跃移组分为主,沟-3悬移组分累积体积分数显著高于沟-1、沟-2,植物配置显著改变底泥颗粒组成和粒度参数;底泥颗粒组成和粒度参数对碳氮磷含量影响显著,其中,分形维数、黏粒体积分数是关键影响因素,表明排水沟植物配置通过影响底泥颗粒组成、粒度参数而显著影响底泥对碳氮磷吸附、固定和分解消减能力,沟-2底泥对碳氮磷吸附固定能力最强,沟-3底泥对碳氮磷分解消减能力最强。因此,农田排水沟混种多种植物,适当提高植被覆盖度,可减弱水动力条件,提高底泥粉粒、黏粒占比,优化底泥粒度参数,增强底泥对有机污染物和氮磷的净化能力。

小粒径蔬菜种子双圆盘精量排种器设计与仿真分析

为减少小粒径蔬菜精量播种过程的漏播率、种子损伤率、种子重播率,设计了双圆盘精量排种器,以提高小粒径蔬菜种子排种器的作业效率。结果表明:排种盘最佳直径为200 mm,厚度为2 mm;运用EDEM离散元软件对排种器排种过程进行仿真分析发现,充种初期,种盒中的种子出现反弹现象,随种子数量的增加,逐渐趋于稳定,当排种盘携种时,盒中种子出现扰动现象。通过对种子和种盒之间碰撞机理、种盒材质及其力学特性分析发现,在排种盘转动阶段,种盒底层靠近排种盘的种子间相互作用增加,底层种子出现扰动现象,导致漏播、损伤、重播加剧。

基质粒径与植株密度对人工湿地净化渗滤液荧光及微生物特性的影响

为了揭示基质粒径、植株密度对人工湿地净化垃圾渗滤液有机物效果的影响,以陶粒、黄菖蒲为试验材料,构建了粒径20 mm+植株密度50株/m^(2)(K1)、粒径20 mm+植株密度75株/m^(2)(K2)、粒径5 mm+植株密度50株/m^(2)(K3)3个人工湿地处理系统,采用三维荧光和变性梯度凝胶电泳技术对其进行分析。结果表明,溶解性有机物(DOM)去除率、荧光强度、微生物多样性及结构粒径间K1与K3差异显著,不同植株密度间K1与K2之间荧光强度、微生物多样性差异显著。粒径变小可显著提高有机物净化,经过21天净化后,K3对DOM的去除率比K1高出29.72%(P<0.05),荧光强度下降5.04(P<0.01),粒径对微生物结构变化影响的贡献率高达57%(P=0.048);植株密度亦可促进有机物去除,显著增加微生物多样性与结构,K2相比K1 f450/500降幅达0.72。表明在应用人工湿地净化垃圾渗滤液时,可通过降低粒径基质与提高密度植株的方式,提升系统微生物丰度及结构多样性,促进有机污染物的去除。

甘肃省民勤县荒漠绿洲过渡带典型灌丛植物的滞尘量效应

[目的]开展荒漠绿洲过渡带典型灌丛滞尘研究,为区域防风固沙树种滞尘效益评价和绿洲防护体系建设提供依据。[方法]通过野外调查采样,室内水洗过滤等方法,定量分析了荒漠绿洲过渡带梭梭(Holoxylon ammodendron)、柽柳(Tamarix chinensis)、白刺(Nitraria tangutorum)3种植物在3月上旬(冬态)和6月下旬(夏态)滞尘量和滞尘粒度沿荒漠至绿洲4 km范围内的时空变化特征。[结果]滞尘量从荒漠到绿洲逐步递减,3月上旬梭梭、柽柳、白刺平均递减20.74%,16.13%,14.72%,6月下旬平均递减14.37%,9.23%,26.54%。3月上旬梭梭的滞尘量最大,约为172.36 g/株~、6月下旬柽柳的滞尘量最大,约为345.16g/株。3月上旬3种灌木所滞尘土的粒径主要为20~50μm,约占41.00%,梭梭有少量滞尘的粒径为500~1000μm,约占总量的15.00%;6月下旬所滞尘土的粒径大量分布于100~200μm,少量分布于5~10μm。[结论]在3月和6月,3种灌木的滞尘量从荒漠到绿洲均呈现出递减的趋势,灌丛植物的滞尘量、滞尘粒径受时间、空间及植物叶表面特征的共同影响。

土壤调理剂及其粒径对酸性红壤的改良效应

针对酸性红壤的特性,结合不同粒径调理剂中物质释放规律的不同,探寻出最优的调理剂粒径。通过模拟水浸提、恒温土培、盆栽试验和野外田间试验的方式,说明随着时间的推移,所有粒径的调理剂在水中的pH值逐渐升高,且粒径越小pH值越大,直至77d时,不同粒径调理剂在水中的pH值无显著性差异;不同粒径调理剂盐基离子(K^(+)、Na^(+)、Ca^(2+)、Mg^(2+))释放量也逐渐降低,刚开始到第21d释放量线性下降,之后慢慢下降最后趋于平稳。在第7d到21d之间,不同粒径调理剂中钾、钠和镁离子的释放量出现了相等的时间点,而钙离子释放量相等的时间段出现在第21d到35d间。土培试验表明所有粒径的调理剂对酸性红壤的pH值,钾钠钙镁离子含量和速效养分含量有不同程度的提升,其中粒径1~2 mm和2~3 mm的调理剂对土壤盐基离子(K^(+)、Ca^(2+)和Mg^(2+))含量提高显著高于其他粒径,分别提高了34.48%和31.03%、61.94%和47.01%与83.33%和70.08%,盆栽花生施用调理剂后,土壤中得pH值增加了0.09~0.18个单位,土壤交换性H+和交换性Al3+含量分别降低了0.01~0.08cmol(+)/kg和0.28~1.48 cmol(+)/kg,田间试验中花生产量较优处理是调理剂粒径1~2 mm和2~3 mm,显著高于其他处理,产量分别提高了25.18%和29.51%,土壤调理剂粒径范围1~2 mm和2~3 mm对酸性红壤的改良效果显著高于其他粒径。

提升多馈入受端电网安全性的储能电站规划方法

多馈入受端电网中交直流相互影响严重,存在多重换相失败的风险,同时受端电网具有低惯量特性,直流闭锁后频率快速下降可能诱发低频减载事故。储能能够实现有功、无功四象限运行,并且响应迅速,在频率、电压两方面均可提高系统的安全稳定性,因此提出一种提升受端电网安全性的双层多目标储能电站规划模型。外层以降低各高压直流间交互作用为目标同时兼顾经济性,进行多目标储能电站选址定容规划;内层利用储能、直流以及抽蓄切泵的紧急有功支撑能力,构建考虑频率安全约束的优化调度模型。采用多目标遗传算法NSGA-Ⅱ与求解器相结合的方法对模型进行求解,最终通过改进的IEEE-39系统验证了所提规划模型的有效性。

化工装置厂区防渗注浆关键技术研究

近几年来,国家对环境保护越来越重视,而化工装置厂区内危险源众多,如液氨、柴油、甲醇等,一旦泄露将对地下水资源和土壤等造成不可逆转的破坏,因此,对化工装置厂区进行防渗处理将是一种必然趋势。由于装置厂区建构筑物较多,特别是已建装置厂区,进行防渗处理时可采用的处理方法受限,强夯、土工铺膜、挤密桩等因为施工工艺的限制均不能进行施工,而注浆由于施工简单,作业面小,在调整钻孔注浆角度后可直接在装置下注浆,且注浆后防渗效果较好,能起到预期的防渗效果,因而化工装置厂区防渗注浆施工会在以后的施工中越来越被社会所认可并广泛采用,具有良好的发展趋势。此文通过对化工装置厂区内防渗注浆关键技术的研究,为今后类似的防渗注浆工程施工提供了理论依据和技术支持。