水氮管理对设施番茄根系生长的影响

为研究高盐分累积设施土壤（电导率为1 106 μS/cm）中水氮管理对设施番茄根系生长的影响,采用二因素随机区组设计,利用盆栽试验研究了设施土壤中不同水分和氮肥处理对番茄生长和养分吸收的影响.结果表明:与适宜灌溉[浇水量为2.1 L/（盆·次）]相比,水分胁迫处理[浇水量为1.5 L/（盆·次）]显著抑制番茄根系、株高和生物量的增加,番茄总根长、根总表面积、根尖数分别平均减少16.6%、24.4%、14.3%,养分吸收量平均减少21.7%;高量灌溉[浇水量为2.7 L/（盆·次）]可增加番茄果期生物量,增幅达35.5%,但氮素吸收量有所降低.与传统施肥相比,减氮施肥可显著促进番茄植株、根系的生长,从而增加养分吸收量;番茄总根长、根总表面积、根尖数分别增加2.9%~55.3%、10.8%~55.5%、4.9%~62.7%,株高平均增加12.7%,养分吸收量平均增加38.5%,氮肥利用率从9.1%增至30.8%.研究显示,在高盐分累积的设施土壤中,氮肥减施可促进作物根系生长,同时提高氮肥利用率.      

Microecosystem Analysis of the Structure and Functions of Forest Biogeocenoses

The microecosystem approach and an adequate system of quantitative methods have been used to study the relationship between the chorologic changes in the structure and functions of edificator tree stand and other components of the pine (Pinus sylvestris L.) forest cenoecosystems of the Transural and Northern Turgai regions. Significant correlations of the density of pine undergrowth with the litter thickness; of its growth with root competition, stand closeness, and, to a lower degree, photosynthetically active radiation (PAR); and of the numbers of small mammals and groups of soil mesofauna with herbaceous phytomass have been found. The possibility of the synthesis of population-ecological, synecological, and biogeocenological methods has been demonstrated.     

Phytoremediation of Soil Polluted by Nickel Using Agricultural Crops

Soil pollution due to heavy metals is widespread; on the world scale, it involves about 235 million hectares. The objectives of this research were to establish the uptake efficiency of nickel by some agricultural crops. In addition, we wanted to establish also in which part of plants the metal is stored for an eventual use of biomass or for recycling the metal. The experiments included seven herbaceous crops such as: barley (Hordeum vulgaris), cabbage (Brassica juncea), spinach (Spinacea oleracea), sorghum (Sorgum vulgare), bean (Phaseolus vulgaris), tomato (Solanum lycopersicum), and ricinus (Ricinus communis). We used three levels of treatment (150, 300, and 600 ppm) and one control. At the end of the biological cycle of the crops, the different parts of plants, i.e., roots, stems, leaves, fruits, or seeds, were separately collected, oven dried, weighed, milled, and separately analysed. The leaves and stems of spinach showed a very good nickel storage capacity. The ricinus too proved to be a very good nickel storer. The ability of spinach and ricinus to store nickel was observed also in the leaves of cabbage, even if with a lower storage capacity. The bean, barley, and tomato, in decreasing order of uptake and storage capacity, showed a high concentration of nickel in leaves and stems, whereas the sorghum evidenced a lesser capacity to uptake and store nickel in leaves and stems. The bean was the most efficient in storing nickel in fruits or grains. Tomato, sorghum, and barley have shown a storage capacity notably less than bean. The bean appeared to be the most efficient in accumulating nickel in the roots, followed in decreasing order by sorghum, ricinus, and tomato. With regard to the removal of nickel, spinach was the most efficient as it contains the highest level of this metal per gram of dry matter. The ricinus, cabbage, bean, sorghum, barley, and tomato evidenced a progressively decreasing efficiency in the removal of nickel.     

湿地植物芦苇根系分泌物的三维荧光光谱表征分析

针对湿地植物芦苇根系分泌物特性不明确的问题,于北京建筑大学大兴校区人工湖实地采集湿地植物芦苇,在实验室水培后采用三维荧光光谱技术考察了芦苇根系分泌溶解性有机物组成随时间的变化规律。结果表明:芦苇根系可分泌溶解性有机物,使根系周围水体有机碳含量增加;芦苇根系分泌物主要为含芳环结构类色氨酸蛋白物质;随时间延长,三维荧光光谱图出现代表微生物代谢物的荧光峰,推测根系周围出现微生物活动,微生物利用根系分泌物生长繁殖,并将类蛋白物质转化为类腐殖酸物质,产生代谢物,使根际周围溶解性有机物组成发生改变。     

Promoting sustainable agriculture development by improvingthe efficiency of chemical fertilizers and soil nutritions

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The diagnostic potential of fetal renal biopsy

The feasibility of fetal renal biopsy has been investigated in order to assess the diagnostic value of the histological specimen. Two fetuses with a severe bilateral renal abnormality (multicystic dysplastic kidney, Meckel-Gruber syndrome with polycystic kidney) and one fetus with Down syndrome (no detectable structural anomaly) were sampled. Histological findings in the biopsy specimens of cases 1 and 2 were diagnostic of an early obstructive renal disease. In case 3 , the findings were consistent with normal development for gestational age of the kidney. Fetal renal biopsy is technically feasible; histological examination of the samples showed a good correlation with postnatal findings. Further studies of its diagnostic value are required.     

基于BaPS系统的旱地土壤呼吸作用及其分量确定探讨

应用气压过程分离(BaPS)方法研究了大豆和玉米种植下土壤呼吸速率及其分量的动态变化,并同时用气相色谱仪分析了实验期间BaPS系统内的CO2气体浓度,对2种方法测定的土壤呼吸速率进行了比较.结果表明:(1)BaPS方法与气相色谱测得的土壤呼吸速率具有一致性和可比性;(2)大豆田根区土壤呼吸速率随根系生长有明显的季节变化,速率为(29.8±6.4)mg·kg-1·d-1(以C计),非根区土壤呼吸速率在整个生长季数值较低并且季节变化不明显,为(14.4±5.1)mg·kg-1·d-1(以C计);玉米种植下土壤呼吸有类似的规律,差别在于玉米根系生物量比大豆大,呼吸速率也高,根区呼吸速率为(70.8±38.6)mg·kg-1·d-1(以C计),非根区为(18.1±8.7)mg·kg-1·d-1(以C计);(3)根起源呼吸是土壤呼吸的重要组成部分,根区与非根区土壤呼吸速率的差值可以认为来自于根系活动,研究发现大豆田根起源呼吸占土壤呼吸的50%,玉米田根起源呼吸占到69%;(4)利用根起源呼吸与根系生物量的相关关系,得到大豆根起源呼吸系数为0.048mg·mg-1·d-1,玉米的根起源呼吸系数较小为0.042mg·mg-1·d-1.     

Early prenatal sonographic diagnosis of neuropathic arthrogryposis multiplex congenita with osseous heterotopia

A prenatal diagnosis of arthrogryposis multiplex congenita (AMC) has been carried out on a 19-week-old fetus by means of echography. The ultrasonographic characteristics were unnatural position of the four limbs associated with articular anomalies together with absence of active fetal movements. A therapeutic interruption of pregnancy was performed and the diagnosis was confirmed. At autopsy, architectural disorder of the motor neurons of the anterior medullary horn revealed a neuropathic pathogenesis of the arthrogryposis. Moreover, at the lumbar level the spinal cord was progressively replaced by heterotopic bony tissue which caused a more severe deformity of the lower limbs compared with the upper. The aspects of anatomo-pathological, genetic, and differential diagnosis are discussed showing the precocity of the prenatal diagnosis and the peculiarity of the aetiology of our case.     

Effects of simulated acid rain on root growth of Cunninghamia lanceolata and Schima superba saplings planted in acidified soil

Results from pot culture (with one-year old Cunninghamia lanceolata and Schima superba) are described. It was found that the biomass production and elongation of C. lanceolata was seriously inhibited at pH 2.0 rain, but for S. superba, was not affected markedly. When pH values of experimental rain were higher than 2.0, the root growth of both species was not adversely affected. Aluminium had already accumulated to some degrees in the roots of both trees, and started to affect the root growth of C. lanceolata at pH 2.0 rain. The soil chemistry was also examined. Increased acidity of experimental rain increased the leaching of Ca and Mg. The Al/Ca mol ratio increased from 0.3 to 0.9 in top soil, and in rhizosphere to 1.5 when the pH values of simulated acid rain were 4.5 to 2.0. In this experiment, NO3- fertilization effect was discovered.     

Menkes X-linked disease: Prenatal diagnosis of hemizygous males and heterozygous females

Menkes X-linked disease, a copper disturbance syndrome, is detectable in cell cultures. Prenatal findings in two at-risk foetuses suggested that prenatal diagnosis was also feasible. In this study, we report substantial evidence that therapeutic abortion can be limited to hemizygous males. Forty-two at-risk pregnancies from 21 European families and 1 Canadian family were monitored with ⁶⁴Cu-uptake into cultured amniotic fluid cells. In 10 pregnancies with a male karyotype an affected foetus was predicted on the basis of the copper studies. The pregnancies were terminated and the diagnosis was in each case confirmed by a markedly increased placenta copper content. Fourteen male foetuses were predicted to be unaffected and none of them has developed signs of Menkes disease after birth. In 6 of these cases the diagnosis was checked in the newborn boy by placenta copper measurements, and they all had copper concentrations within normal limits. Eighteen pregnancies with a female karyotype were also studied. 9 females could be identified as carriers on the basis of the tissue culture studies or raised placenta copper values.