根系吸水机理研究进展

植物根系除支撑和固定其地上部这一力学功能外的一个重要功能就是从土壤中吸收水分和养分以满足植物地上部生长所需.表征植物根吸水能力的一个重要的水力学参数是水力导度(用单位时间单位面积的水流速率来表示),可在细胞(细胞水力导度)、单根和整株根系水平上来表达,其中单根导度可分为径向导度和轴向导度,仅径向导度反映了单根吸收水分的能力,而轴向导度则反映了植物根系输导水分的能力,但在整株根系水平上则以通过整个根系的水流通量与根木质部和根表土壤间的水势差之比来表示,既包括径向导度也包括轴向导度.近年来,对植物根系吸水或根水…     

Ri质粒转化烟草的影响因素及豌豆凝集素基因在烟草发根中的表达

对Ri质粒转化烟草的影响因素进行研究,以期获得较为理想的实验系统,用发根农杆菌介导,将豌豆凝集素基因导入烟草,获得转基因的烟草发根,GUS组织化学染色,蛋白免疫原位杂交证明,gus报告基因和豌豆凝集素基因已在转基因烟草发根中得到了转译表达,本结构将为瘤菌能否扩大宿主范围,为研究烟草与豌豆根瘤菌相互作用,结瘤固氮的可能性奠定基础。     

反社会型人格障碍学生的管理——由某学生行为引发的思考

高校学生管理工作是高等学校教书育人的基本保障。针对近期频发的校园暴力事件,以某学生的表现及行为特点为例,从心理学角度介绍反社会型人格障碍的含义和特征,分析其产生的根源,并提出对反社会型人格障碍学生管理几点建议。     

Effects of used lubricating oil on two mangroves Aegiceras corniculatum and Avicennia marina

An outdoor experiment was set up to investigate the effects of used lubricating oil(5 L/m~2)on Aegiceras corniculatum Blanco. and Avicennia marina(Forsk)Vierh.,two salt-excreting mangroves.A.marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling.When treated with canopy-oiling,half of A.corniculatum plants survived for the whole treatment time(90 d);but,for A.marina,high mortality (83%)resulted from canopy-oiling within 3 weeks and no plants survived for 80 d.Base-oiling had no lethal effects on A.corniculatum plants even at the termination of this experiment,but 83% of A.marina plants died 80 d after treatment.Forty days after canopy- oiling,93% ofA.corniculatum leaves fell and no live leaves remained on A.marina plants.By the end of the experiment,base-oiling treatment resulted in about 45% ofA.corniculatum leaves falling,while all A.marina leaves and buds were burned to die.Lubricating oil resulted in physiological damage to A.corniculatum leaves,including decreases in chlorophyll and carotenoid contents,nitrate reductase,peroxidase and superoxide dismutase activities,and increases in malonaldehyde contents.For both species,oil pollution significantly reduced leaf,root,and total biomass,but did not significantly affect stem biomass.Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.     

臭氧污染、氮沉降和干旱胁迫交互作用对杨树叶和细根非结构性碳水化合物的影响

快速城市化和工业化进程,导致植物生长季常暴露于高浓度地表臭氧(O3)、干旱和氮(N)沉降的环境中.为探究植物非结构性碳水化合物(NSC)及其组分(可溶性糖和淀粉)对多重环境因子胁迫的响应格局,本实验设置2个O3 处理(对照,以过滤空气计;增加O3,未过滤空气+40 nmol·mol-1 O3)、2个水分处理(充分灌溉;...     

硅对过量锰胁迫下水稻根系抗氧化系统和膜脂质过氧化作用的调控机理

揭示Mn胁迫下Si对水稻根系抗氧化系统的影响机制,可为减轻水稻Mn毒害提供重要的理论依据和技术支持.因此,本研究通过水培试验,采用两个对Mn耐性不同的水稻品种,研究Si(1.5 mmol·L-1)对Mn(2 mmol·L-1)胁迫下水稻根系抗氧化系统的影响.结果表明,在Mn胁迫下,敏感品种新香优640(XXY)根系的超...     

不同类型地膜覆盖对土壤质量、根系生长和产量的影响

针对我国农业生产中地膜大规模使用带来的土壤环境污染问题,通过应用降解地膜进行大田试验,以南瓜为研究试材,探究了黑色普通地膜(CK)、白色降解地膜(WDF)、黑色降解地膜(BDF)和黑色CO₂基降解地膜(C-DF)对土壤理化性质、根系生长与产量的影响,并对土壤质量进行评估.结果表明,3种降解地膜处理土壤含水量和温度,较普通地膜均不同程度降低;各处理间土壤有机质含量无显著差异;C-DF处理土壤速效钾含量较CK降低,WDF和BDF无显著影响;BDF和C-DF处理土壤全氮和速效氮含量较CK和WDF降低,处理间差异达到显著水平.3种降解膜处理土壤过氧化氢酶活性较CK显著提升2.9%～6.8%,蔗糖酶较CK显著降低了33.3%～38.4%.BDF处理土壤纤维素酶活性较CK显著提升63.8%,WDF和C-DF无显著影响.3种降解膜处理对地下部根系生长具有促进作用,长势明显增强.BDF和C-DF处理南瓜产量与CK趋近,BDF处理南瓜产量较CK显著降低11.4%.试验结果表明,BDF和C-DF处理对土壤质量和产量的影响与CK相当.研究认为2种黑色的降解地膜在高温生产季节可有效替代普...     

科尔沁沙地三种常见乔木根-土界面水分再分配初探

根-土界面水分再分配研究对于干旱、半干旱地区退化植被的恢复与重建具有重要意义,同时也是国际植物生理生态学和生态水文学界十分关注的研究领域之一.为了探明科尔沁沙地优势乔木树种樟子松(Pinus sylvestris var.mongolica)、小叶杨(Populus simonii Carr.)、榆树(Ulmus pumila)是否具有根-土界面水分再分配的现象,我们利用时域反射仪(TDR)每隔2 h连续测定植株根际土壤水分,同时应用干沙瓶分根法对3种乔木根-土界面水分再分配作了测定,结果表明:三种常见乔木树种樟子松、小叶杨、榆树均具有根-土界面水分再分配的潜力;并且榆树的水分再分配能力较樟子松和小叶杨强;三种常见乔木根-土界面水分再分配现象一般发生在14:00之后,而分配水量最大的时间多是出现在次日凌晨4:00左右,即4:00-14:00为植物的蒸腾耗水时段,而14:00至次日4:00为植物的水分再分配时段.     

Functional traits of poplar leaves and fine roots responses to ozone pollution under soil nitrogen addition

Concurrent ground-level ozone（O₃） pollution and anthropogenic nitrogen（N） deposition can markedly influence dynamics and productivity in forests.Most studies evaluating the functional traits responses of rapid-turnover organs to O₃ have specifically examined leaves,despite fine roots are another major source of soil carbon and nutrient input in forest ecosystems.How elevated O₃ levels impact fine root biomass and biochemistry remains to be resolved.This study was...     

Editorial: Effect of root anatomy and apoplastic barrier development on cadmium uptake in rice

<正>Cadmium (Cd) is a toxic metal with high mobility from soil and known translocation into plants (Song et al., 2015).Because the main source of human exposure to Cd is from food consumption, there has been increased research examining Cd uptake in agricultural plants (Li et al., 2014; Rizwan et al., 2016; Song et al., 2015). Rice (Oryza sativa L.) has been identified as a major crop that contains relatively high