Physiological Characterization of Zn-efficient Rice (Oryza sativa) Genotype at Different Zn^(2+) Levels

Physiological characteristics of rice at different Zn^(2+) levels[pZn^(2+)>11.5, 11.3, 11.0, 10.6, 10.3, 9.7] were studied with the Zn-efficient rice cultivars IR34, IR36, IR8192, and Zn-inefficient rice cultivars IR26, Ce 64-7, Biyuzaonuo, which grew in chelator-buffered nutrient solution. There were significant differences in tolerance to zinc deficiency among different rice genotypes. Obvious effects of low zinc activity on the physiological characteristic of rice seedlings were noted. There were significant differences in chlorophyll content, photosynthesis rate, MDA concentration in rice leaf, and H^+ excretion of root. As pZn^(2+) decreased, chlorophyll content and photosynthesis rate decreased at a slower pace in Zn-efficient cultivars compared to Zn-inefficient ones, MDA concentration increased slower while H^+ excretion of root increased faster in Zn-efficient cultivars than those in Zn-inefficient ones. It was suggested that the above indications could be used as indexes to Zn-efficiency of rice.

Effects of nitrogen fertilization strategies on nitrogen use efficiency in physiology, recovery, and agronomy and redistribution of dry matter accumulation and nitrogen accumulation in two typical rice cultivars in Zhejiang, China

Field experiments were conducted in farmers’ rice fields in 2001 and 2002 to study the effects of nitrogen (N) man-agement strategies on N use efficiency in recovery (RE), agronomy (AE) and physiology (PE) and redistribution of dry matter accumulation (DMA) and nitrogen accumulation (NA) in two typical rice cultivars in Jinhua, Zhejiang Province. This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency (NUE) of rice in Zhejiang by comparing farmers’ fertilizer practice (FFP) with advanced site-specific nutrient management (SSNM) and real-time N management (RTNM). The results showed that compared to FFP, SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering. There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution (post-DMR) and post-flowering nitrogen redistribution (post-NR). These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer’s routine practice of Zhejiang. With SSNM, about 15% of the current total N input in direct-seeding early rice and 45% in single rice could be reduced without yield loss in Zhejiang, China.

Deciphering the morpho–physiological traits for high yield potential in nitrogen efficient varieties(NEVs):A japonica rice case study

The use of nitrogen(N)-efficient rice(Oryza sativa L.) varieties could reduce excessive N input without sacrificing yields. However, the plant traits associated with N-efficient rice varieties have not been fully defined or comprehensively explored. Here, three japonica N-efficient varieties(NEVs) and three japonica N-inefficient varieties(NIVs) of rice were grown in a paddy field under N omission(0 N, 0 kg N ha^(-1)) and normal N(NN, 180 or 200 kg N ha^(-1)) treatments. Results showed that NEVs exhibited higher grain yield and nitrogen use efficiency(NUE) than NIVs under both treatments, due to improved sink size and filled-grains percentage in the former which had higher root oxidation activity and greater root dry weight, root length and root diameter at panicle initiation(PI), as well as higher spikelet-leaf ratio and more productive tillers during the grain-filling stage. Compared with NIVs, NEVs also exhibited enhanced N translocation and dry matter accumulation after heading and improved flag leaf morpho-physiological traits, including greater leaf thickness and specific leaf weight and higher contents of ribulose^(-1),5-bisphosphate carboxylase/oxygenase, chlorophyll, nitrogen, and soluble sugars, leading to better photosynthetic performance. Additionally, NEVs had a better canopy structure, as reflected by a higher ratio of the extinction coefficient for effective leaf N to the light extinction coefficient, leading to enhanced canopy photosynthesis and dry matter accumulation. These improved agronomic and physiological traits were positively and significantly correlated with grain yield and internal NUE, which could be used to select and breed N-efficient rice varieties.

Physiological Characteristics of Nitrogen Nutrition in Peanut and Efficient Nitrogen Application Technology

Nitrogen plays a very important role in peanut nutrition and fertilization.For peanuts,the nitrogen nutrition comes from root nodules,soil and fertilizer,which are separately referred to as root nodule nitrogen,soil nitrogen and fertilizer nitrogen.The research obtained following findings.(ⅰ)The nitrogen supply ratio of the three nitrogen sources for peanut is about 5∶3∶2.There are significant differences in the nitrogen supply capacity of the three nitrogen sources.The root nodules have the largest variation in nitrogen fixation and have a high potential for development.Nitrogen fixation in root nodules is closely related to carbon metabolism indicators such as photosynthesis in peanut leaves.Phosphorus application could increase the accumulation of three nitrogen sources,and the increase in nodule nitrogen accumulation is greater than that of soil nitrogen and fertilizer nitrogen.(ⅱ)Nitrogen fertilizer has a significant effect on nitrogen nutrition of peanuts.Different forms of nitrogen fertilizers,such as amide nitrogen,ammonium nitrogen,nitrate nitrogen and mixed ammonium nitrate nitrogen,have significant effects on nitrogen metabolism and nitrogen accumulation in peanuts.Amide nitrogen fertilizer is beneficial to improving the activity of enzymes related to nitrogen metabolism and nitrogen accumulation.Controlled-release fertilizer can significantly increase the content of soluble protein and improve the activities of NRase,GDH,GS,GPT,etc.in roots and leaves at the pod setting and mature stages of peanuts,which is favorable for delaying the plant senescence and increasing the yield of peanuts.Mixed application of common nitrogen fertilizer and slow-release fertilizer can increase the soil nitrate nitrogen level at the later growth stage,which is beneficial to the development of the root system at the later stage of growth,increasing the distribution ratio of nitrogen in the pods,and also favorable for increasing the yield and nitrogen utilization rate.(ⅲ)Increasing the ploughing depth,improving fertilization methods,selecting nitrogen-efficient varieties,paying attention to foliar topdressing,and adopting fertilizer-water integrated cultivation are conducive to increasing the nitrogen utilization rate of peanuts,reducing the amount of nitrogen fertilizers,accordingly saving costs,increasing efficiency and realizing sustainable development of agricultural production.

Effects of Gel-based Controlled Release Fertilizers on Agronomic Characteristics and Physiological Indices of Corn

[Objective] This study aimed to investigate the effects of gel-based controlled release fertilizers （CRFs） on agronomic characteristics and physiological indices of corn. [Method] Pot experiment was carried out to investigate the agronomic characteristics and physiological indices of corn fertilized with controlled release fertilizers compared with conventional fertilizer （CF）. [Result] Plant height, stem girth, leaf area and root volume of corn were significantly increased under the CRF treatments; photosynthetic rate and soluble protein content were also improved. Dry matter accumulations under the two CRF treatments were increased by 21.3% and 17.0% compared with CF application at one time （CF1）, and 19.6% and 15.4% with CF application at two times （CF2）, respectively. Accumulation amounts of N, P and K in whole plant under the two CRF treatments were increased by 44.0% -24.7% , 40.0%-25.9% and 20.1% -13.9% ; and the nutrient use efficiencies of N, P and K were improved by 22.9% -13.4% , 11.2% -9.6% and 17.5% -12.1% , respectively. [Conclusion] The results implied that the CRFs could significantly improve nutrient use efficiency and plant yield.

Physiological Effect and Quality Influences of Hedyotis diffusae Extract on Tobacco Infected by TMV

The extract from Hedyotis diffusae was used to treat tobacco plants infected by TMV before and after incidence. The effect of the changes of some physiological and biochemical indices related with the virus-resistance in tobacco leaves on tobacco quality ware determined. The resuits showed that H. diffusae extract could remarkably increase the total phenol content in tobacco leaves ,strength the activity of phenylalanine ammonialyase （ PAL） , improve the membrane permeability and tobacco quality. Prevention treatment was better than therapy treatment. In conclusion, H. diffusae extract could induce plants to produce disease resistance and strength tha antiviral capability of tobacco against TMV.

Physiological Studies on Ratoonability of Sugarcane Varieties under Tropical Indian Condition

The ratoon crop occupies approximately 40% of the total area of sugarcane crop in tropical India. The main reason for the lower average cane productivity is the yield decline in ratoon crops (40 - 50 t/ha) despite the release of the high yielding varieties and advanced cane production technology. The physiological factors associated with ratooning performance and the variation in growth and yield were studied in 11 sugarcane varieties in two cycles of one plant and two ratoon crops each. The first ratoon and second ratoon crop showed 17.0% and 28.1% reduction in tiller production and 15.5% and 15.7% reduction in NMC, respectively, over plant crop. The differences in growth parameters between the plant and ratoon crops at the formative phase were lesser than that of grand growth and maturity phases. Varieties Co 86032, Co 97008, Co 95020 Co 99004 and Co 2000-10 showed better physiological efficiency in terms of plant height, shoot population, leaf size, TDMP, partitioning efficiency, chlorophyll content and nitrate reductase activity and significantly higher yield components such as NMC, SCW, cane length, internodal length as well as cane yield compared to other varieties. The higher reduction in ratoon yield in Co 99008, Co 94012, Co 8021 and Co 97009 (>35.00% reduction) was due to higher reduction in tiller production associated with stunted plant growth and root system, reducetion in individual leaf size and LAI, TDMP, total chlorophyll content, NMC, internodal length and SCW. The results obtained indicated that the plant height, TDMP, stem partitioning, leaf size, total chlorophyll content, SCW, cane length and cane girth were highly associated with yield of first and second ratoon crops than that of plant crop. Therefore the difference in the association between physiological parameters with yield of plant and ratoon crops therefore decides the ratooning potential of the crop.

Morphological and physiological traits of large-panicle rice varieties with high filled-grain percentage

financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;the Great Technology Project of Ningbo, China （2013C11001）

Nitrogen availability regulates deep soil priming effect by changing microbial metabolic efficiency in a subtropical forest

In terrestrial ecosystems,deep soils(below 30 cm)are major organic carbon(C)pools.The labile carbon input could alter soil organic carbon(SOC)mineralization,resulting in priming effect(PE),which could be modified by nitrogen(N)availability,however,the underlying mechanism is unclear for deep soils,which complicates the prediction of deep soil C cycling in response to N deposition.A series of N applications with ^(13)C labeled glucose was set to investigate the effect of labile C and N on deep SOC mineralization.Microbial biomass,functional community,metabolic efficiency and enzyme activities were examined for their effects on SOC mineralization and PE.During incubation,glucose addition promoted SOC mineralization,resulting in positive PE.The magnitude of PE decreased significantly with increasing N.The N-regulated PE was not dependent on extracellular enzyme activities but was positively correlated with carbon use efficiency and negatively with metabolic quotient.Higher N levels resulted in higher microbial biomass and SOC-derived microbial biomass than lower N levels.These results suggest that the decline in the PE under high N availability was mainly controlled by higher microbial metabolic efficiency which allocated more C for growth.Structural equation modelling also revealed that microbial metabolic efficiency rather than enzyme activities was the main factor regulating the PE.The negative effect of additional N suggests that future N deposition could promote soil C sequestration.

Research Progress on Water Use Efficiency and Drought Resistance of Turfgrass

Improving turfgrass drought resistance and save-water features are very important to solve water deficiency in turfgrass production and management. This research did some surveys of systematic literature review about turfgrass drought tolerance morphological characteristics, physiological characteristics and water use efficiency, and provided the detailed information for enhancing turfgrass drought resistant and water use efficiency in the future.

不同灌溉模式对籼粳杂交稻甬优1540产量与水分利用效率的影响

旨在探讨不同灌溉模式对籼粳杂交稻甬优1540产量与水分利用效率的影响,并阐明其相关生理基础。本研究以甬优1540为材料,设置了3种灌溉模式,即长淹灌溉(continuous flooding,CF)、轻度干湿交替灌溉(alternate wetting and moderate drying, AWMD)以及重度干湿交替灌溉(alternate wetting and severe drying, AWSD)。研究结果表明,与CF相比, AWMD与AWSD均能显著提高水分利用效率,增幅分别为22.6%~25.6%与18.2%~23.1%;AWMD可以显著提高水稻产量,增幅为8.6%~10.0%,而AWSD则显著降低水稻产量,降幅为6.0%~7.5%。与CF相比, AWMD显著降低了拔节期水稻的茎蘖数、地上部干物质重、叶面积指数、移栽至齐穗期的光合势以及移栽至拔节期的作物生长速率,但显著提高了茎蘖成穗率、拔节至齐穗期的作物生长速率、主要生育期水稻根长密度、深根比、比根长、根系总吸收表面积与活跃吸收表面积,以及灌浆后2次土壤复水期的剑叶净光合速率、根系氧化力、根系与叶片中玉米素和玉米素核苷(Z+ZR)含量、籽粒中蔗糖-淀粉代谢途径关键酶活性等指标。以上结果表明, AWMD可以协同提高甬优1540产量与水分利用效率,优化根-冠生长发育特征,提高灌浆期植株生理活性,实现高产与水分高效利用,为本研究最佳水分管理模式。

不同程度、频率干旱锻炼对冬小麦水分生产力的影响

为探究不同程度、频率干旱锻炼对冬小麦生理指标、产量和水分利用效率的影响,筛选出合理的干旱锻炼模式,以小偃22为试验材料,选择2种干旱胁迫水平(轻度干旱胁迫:50%~60%FC;中度干旱胁迫:40%~50%FC。FC为田间持水量)和2种干旱锻炼模式(单次干旱锻炼和反复干旱锻炼),以全生育期充分供水(CK,70%~80%FC)为对照(CK),设置仅在抽穗期轻度干旱胁迫(ND-1)、抽穗期中度干旱胁迫(ND-2)、分蘖期轻度干旱胁迫+抽穗期轻度干旱胁迫(D-1)、分蘖期中度干旱胁迫+抽穗期中度干旱胁迫(D-2)、分蘖期轻度干旱胁迫及反复锻炼+抽穗期轻度干旱胁迫(DRD-1)、分蘖期中度干旱胁迫及反复锻炼+抽穗期中度干旱胁迫(DRD-2)共7个处理。通过桶栽试验,测定分析了不同干旱锻炼处理下小麦的光合相关指标、抗氧化参数、渗透调节物质含量、产量和水分利用效率。结果表明,与CK相比,ND-1、ND-2处理下冬小麦产量和水分利用效率显著降低,其中产量降幅分别为13.9%和21.2%,水分利用效率降幅均为5.9%;D-1处理下冬小麦的净光合速率、气孔导度、蒸腾速率、光合活性、热耗散能力、叶绿素a含量和叶绿素b含量分别提高13.7%、31.4%、24.7%、1.4%、5.0%、2.7%和4.7%,DRD-1处理下分别提高14.9%、36.1%、27.1%、2.3%、5.1%、12.0%和13.0%。与ND-1处理相比,D-1、DRD-1处理的超氧化物保护酶和脯氨酸的反应速度以及可溶性糖的生成速度均显著加快,D-1处理增幅分别为19.7%、68.3%和31.8个百分点,DRD-1处理增幅分别为24.0%、76.0%、和34.3个百分点;两个处理的过氧化物酶活性均显著减小,降幅分别为8.3%和10.3%;抽穗期复旱对净光合速率、光能转化效率、光化学猝灭系数以及光合色素含量均未产生显著影响,说明超氧化物歧化酶活性和脯氨酸可用于评价作物的抗旱性,轻旱锻炼提高了冬小麦的抗旱性。干旱锻炼对冬小麦增产效果表现为轻度干旱锻炼>中度干旱锻炼,反复干旱锻炼>单次干旱锻炼>不进行干旱锻炼,其中分蘖期轻度单次和反复干旱锻炼均显著增产,产量增幅分别为5.7%和11.4%,使水分利用效率分别提高8.7%和10.9%。综合认为,分蘖期轻度反复干旱锻炼是提高冬小麦抗旱性、产量和水分利用效率的合理调亏灌溉措施。

不同灌水定额对2种油莎豆生长、产量及水分利用效率的影响

【目的】探究南疆地区灌水定额对不同品种油莎豆生理生长、产量及水分利用效率的影响,制定科学合理的灌溉制度。【方法】采用河南圆粒(HY)和内蒙古圆粒(NY)2个油莎豆品种,设置W1(18 mm)、W2(27 mm)、W3(36 mm)和W4(45 mm)4个灌水定额,分析土壤储水量、各生育期的株高、分蘖数、光合特性、产量、耗水量和水分利用效率变化。【结果】2个品种油莎豆土壤储水量和耗水量均随灌水定额增大而增加,W4处理储水量和耗水量较W1处理分别增加24.84%、60.57%(HY)和18.46%、55.61%(NY)。HY油莎豆株高、分蘖数、净光合速率(Pn)、气孔导度(Gs)、叶片蒸腾速率(Tr)和产量均随灌水定额增大呈显著增加趋势(P<0.05),W4处理较W1处理分别增加24.60%、15.11%、28.14%、34.86%、40.49%和13.92%,胞间CO_(2)浓度(Ci)随灌水定额增大呈减小趋势,W1处理较高。而NY油莎豆株高、分蘖数、Pn、Gs、Tr和产量均随灌水定额增大呈先增加后减小趋势,W2处理较W1处理分别增加26.07%、20.26%、19.69%、38.38%、44.92%和20.83%,Ci随灌水定额增大呈先减小后增大趋势,W2处理较低。不同处理油莎豆水分利用效率和灌溉水利用效率均随灌水定额增大呈减小趋势,W1处理显著优于其他处理。主成分分析表明,净光合速率和水分利用效率可作为油莎豆水分和品种筛选的指标。【结论】河南圆粒灌水定额为45 mm,内蒙古圆粒灌水定额为27 mm时更有利于油莎豆的生长,提升产量和水分利用效率。

效率医疗背景下的全程护理模式对前列腺癌根治术患者的影响

目的探讨效率医疗背景下的全程护理模式对前列腺癌根治术患者并发症和生理功能的影响。方法开展前瞻性随机对照试验。选取2021年3月至2022年3月于无锡市第二人民医院接受前列腺癌根治术的126例患者作为研究对象,按照随机数字表法分为两组,各63例。对照组年龄(52.34±4.47)岁,病程(8.56±3.46)个月,采用常规护理模式;观察组年龄(50.78±5.25)岁,病程(8.14±3.62)个月,采用以效率医疗为背景的全程护理模式。对比两组患者康复指标、并发症发生率、生理功能[采用国际勃起功能问卷表-5(IIEF-5)对患者术前、术后1个月及3个月勃起功能进行评估]及护理前后生活质量[采用健康调查量表36(SF-36)评估]。统计学方法采用t检验、χ^(2)检验。结果观察组首次排气时间、首次进食时间、首次下床时间以及住院时间均短于对照组[(22.87±4.62)d比(37.58±4.24)d、(4.65±1.68)d比(6.88±1.03)d、(2.53±1.09)d比(5.36±1.23)d、(8.65±2.15)d比(15.78±2.68)d],差异均有统计学意义(t=18.619、8.982、13.668、16.471,均P<0.05)。观察组并发症发生率为6.35%(4/63),低于对照组的25.40%(16/63),差异有统计学意义(χ^(2)=8.558,P=0.003)。术前,两组患者IIEF-5评分比较,差异无统计学意义(P>0.05);术后1个月、3个月,观察组IIEF-5评分均高于对照组[(13.14±3.68)分比(9.98±4.25)分、(18.22±4.31)分比(11.54±3.93)分],差异均有统计学意义(t=4.461、9.090,均P<0.05)。护理前,两组患者身体功能、情感角色、社会功能、心理健康、身体角色、一般健康、身体疼痛、活力评分比较,差异均无统计学意义(均P>0.05);护理后,观察组身体功能、情感角色、社会功能、心理健康、身体角色、一般健康、身体疼痛、活力评分均高于对照组[(61.67±10.36)分比(55.98±11.68)分、(73.24±12.38)分比(66.20±14.36)分、(67.29±16.46)分比(61.01±12.23)分、(79.13±9.41)分比(72.01±9.10)分、(66.85±13.15)分比(59.42±15.48)分、(63.78±11.42)分比(57.21±9.16)分、(73.45±11.40)分比(63.21±15.46)分、(81.97±12.46)分比(74.43±14.14)分],差异均有统计学意义(t=2.639、2.947、2.431、4.317、2.903、3.562、4.231、3.100,均P<0.05)。结论采用以效率医疗为背景的全程护理模式,前列腺癌根治术患者恢复期缩短,并发症发生率减少,术后勃起功能有所改善,同时提高患者生活质量。

血清NGAL水平联合APACHEⅡ评分对重症肺炎并发急性肾损伤患者预后的预测价值

目的探讨血清中性粒细胞明胶酶相关脂质运载蛋白(NGAL)水平联合急性生理和慢性健康状况评估Ⅱ(APACHEⅡ)评分对重症肺炎并发急性肾损伤(AKI)患者预后的预测价值。方法选取161例重症肺炎并发AKI患者作为AKI组,80例单纯重症肺炎患者作为非AKI组,再根据AKI组患者入院30 d的预后情况将其分为死亡组(n=54)和存活组(n=107)。比较AKI组和非AKI组患者的血清NGAL水平和APACHEⅡ评分。比较死亡组和存活组患者的临床资料,采用多因素Logistic回归模型分析重症肺炎并发AKI患者预后的影响因素,绘制受试者工作特征(ROC)曲线评估血清NGAL水平联合APACHEⅡ评分对重症肺炎并发AKI患者预后的预测价值。结果与非AKI组比较,AKI组患者血清NGAL水平和APACHEⅡ评分升高(P<0.05)。年龄增长、AKI分期2~3期、血清NGAL水平升高和APACHEⅡ评分升高为重症肺炎并发AKI患者死亡的独立危险因素(P<0.05)。ROC曲线分析结果显示,血清NGAL水平联合APACHEⅡ评分预测重症肺炎并发AKI患者预后的曲线下面积为0.873,大于血清NGAL水平和APACHEⅡ评分单独预测的曲线下面积(P<0.05)。结论重症肺炎并发AKI患者血清NGAL水平和APACHEⅡ评分升高与预后不良密切相关,血清NGAL水平联合APACHEⅡ评分对重症肺炎并发AKI患者预后具有较高的预测效能。

超高海拔隧道施工人员生理指标变化及劳动强度研究

为评估超高海拔隧道施工人员劳动强度,采用理论分析法确定施工人员劳动强度评价指标,并依托某超高海拔隧道采用可穿戴设备监测分析不同工序施工过程中人员生理指标变化,进而计算不同工序人员劳动强度及劳动效率。研究结果表明:不同工序施工人员劳动过程中生理指标变化存在明显区别,其中,二衬钢筋布设人员心血管负荷超过卫生限值,机械操作人员血氧饱和度(SpO 2)低于规范值;超高海拔隧道二衬钢筋布设劳动强度为Ⅴ级,底板施工与仰拱钢筋绑扎劳动强度等级为Ⅲ级,二衬防水布铺设与机械操作人员劳动强度等级为Ⅱ级;海拔4700 m时,隧道施工人员劳动效率仅为平原地区的76%~88%;完成与平原地区相同的工作量,相应工序的人工工日消耗需要增加13.63%~31.58%。

德夯岩溶河谷异质生境中半蒴苣苔的水分生理生态适应性

以湘西世界地质公园德夯岩溶河谷内克隆植物半蒴苣苔(Hemiboea subcapitata)为材料,测定其生长、形态与光合水分生理指标,探究其对德夯岩溶台地河谷演化中形成的三类异质生境(峡谷岩壁表面、风化碎裂岩表和河岸有机质层)的水分生理生态适应性。结果显示:(1)异质生境中半蒴苣苔单(分)株叶片自然含水量仅有较小差异(<2%),而相对含水量和自然饱和亏则无显著差异;异质生境中叶片水分需求随基质含水量降低而明显增加,但叶片水势也随之显著降低。(2)单株生长差异大但群体累积生物量无明显差异。如峡谷岩壁表面单株的株高和叶面积均显著高于河岸有机质层单株,但群体累积株高、累积叶面积差异不显著。(3)单株外部形态变化显著,匍匐茎长度、直径和根着生密度均呈现峡谷岩壁表面>风化碎裂岩表>河岸有机质层的趋势;峡谷岩壁表面单株叶片比河岸有机质层单株平均增厚近60μm,比叶面积则降低至其78.2%,气孔密度则显著降低至其66%。(4)光合生理指标中,叶片气孔限制值随叶片水势降低而显著增加,同时气孔导度明显提升,故而胞间CO_(2)浓度并无明显变化,但峡谷岩壁表面单株叶片的净光合速率仅达到河岸有机质层单株叶片的69.6%。(5)水分亏缺最多的峡谷岩壁表面单株叶片水分利用效率却最低(3.029±0.461μmol CO_(2)·mmol^(-1)H_(2)O),仅为河岸有机质层单株的73%。表明,半蒴苣苔可通过自身水分维持机制来保证岩溶异质生境中单株水分的相对稳定,并以增加根系密度、匍匐茎长度、叶片厚度和重量,减少气孔密度等形态可塑性来适应干旱的岩溶岩壁生境,通过增加气孔导度保持蒸腾拉力来维持胞间CO_(2)浓度,以高耗水来维持生长状态相对稳定的方式达成对岩溶河谷水分异质性生境的适应。

LED光照强度对高羊茅生长及生理特性的影响

为通过LED光源在适宜光照强度下培育高质量草坪,本研究以高羊茅(Festuca arundinacea)品种‘交战4’为试验材料,在LED红蓝光源下设置100(L100)、150(L150)、200(L200)、250(L250)、300(L300)、350(L350)μmol·(m^(2)·s)^(-1)的光照强度处理,研究不同光照强度对高羊茅形态建成、生理特性和电能利用效率的影响。结果表明,光照强度低于200μmol·(m^(2)·s)^(-1)时,明显抑制高羊茅形态建成、营养物质积累和抗氧化能力。随着光照强度的增加,高羊茅归一化植被指数和色泽逐渐提升,根系生长更为强壮,有利于高羊茅的生物量积累和抗氧化能力增强。但当光照强度增加至300μmol·(m^(2)·s)^(-1)时,光照强度对高羊茅生长的促进效果减弱。利用LED培育高羊茅电能利用效率在L350处理显著低于L100、L150、L300处理。回归分析显示,在光照强度为291.25μmol·(m^(2)·s)^(-1)时[接近300μmol·(m^(2)·s)^(-1)],高羊茅归一化植被指数最大。因此,综合认为选择光照强度为300μmol·(m^(2)·s)^(-1)时,可以满足高羊茅的正常生长,保持较高的草坪质量,减少能源的消耗。

龙葵与3种外来入侵植物对Cd的富集和生理响应差异比较

为研究本土Cd超富集植物龙葵(Solanum nigrum L.)和3种外来入侵植物鬼针草(Bidenspilosa L.)、紫茎泽兰(Ageratina adenophora Spreng)和紫茉莉(Mirabilisjalapa L.)对Cd污染土壤修复效果和生理响应的差异,采用室内盆栽试验,通过设置0、2、10、30 mg·kg^(-1)不同Cd含量,探究本地种龙葵与3种入侵植物在不同Cd含量处理下对Cd富集、Cd提取效率、叶片光合色素含量、抗氧化酶活性、丙二醛和可溶性糖含量的变化。结果表明:在Cd处理下,鬼针草的地上部生物量均显著高于龙葵和其余2种入侵植物。所有Cd含量处理,鬼针草Cd提取效率均最高(0.61%~1.87%),紫茉莉最低(0.02%~0.03%),龙葵(0.30%~0.79%)和紫茎泽兰(0.24%~1.06%)居中。3种Cd含量处理下,鬼针草叶片叶绿素a、叶绿素b和类胡萝卜素含量在4种植物中最高,鬼针草叶片的抗氧化酶活性均显著高于龙葵,龙葵丙二醛含量显著高于入侵植物。逐步回归分析结果表明,龙葵Cd提取效率与叶片丙二醛含量呈显著负相关、与CAT活性呈显著正相关,鬼针草和紫茎泽兰Cd提取效率均与叶片丙二醛含量呈显著负相关。综上,对于含Cd 2~30 mg·kg^(-1)的土壤进行植物修复时,入侵植物鬼针草比本地植物龙葵更具优势。

近岸浮游植物对海洋油污染的响应研究

近岸浮游植物作为海洋生态系统中的重要生产者,其对环境变化尤其是油污染的响应能够显著影响海洋的生态平衡。尽管目前关于海洋油污染的研究较多,但关于浮游植物对油污具体响应机制仍有待深入研究,尤其是在不同油污浓度下的系统性生理变化。本研究通过室内实验,研究了不同浓度船用柴油对浮游植物生长、光合效率、叶绿素a浓度、脂类含量以及抗氧化酶活性的影响。结果显示:1)油污染显著抑制浮游植物的生长,降低光合作用效率和叶绿素a浓度,影响脂类含量,并诱导抗氧化酶活性的增加,表明浮游植物通过启动抗氧化防御机制应对油污染压力;2)胁迫响应蛋白活性随油污染浓度增加而显著上升。研究揭示了油污染对近岸生态系统中浮游植物的剂量依赖性影响,为理解油污染的生态效应及制定海洋生态保护策略提供了重要信息。