Study of variegated and white flower petals of Capparis spinosa expanded at dusk in arid landscapes

In this study,we provide the first evidence of two pairs of petals of the rapidly expanded and short-lived nocturnal flowers of Capparis spinosa L.(caper)during the prolonged drought period in Eastern Mediterranean region.The corolla of the winter-deciduous,perennial C.spinosa consists of two pairs of petals:a pair of white distinct petals and a pair of connate variegated petals with green basal parts.The results indicated the presence of substantially different amounts of chlorophyll in the two pairs of petals,while their carbohydrates’content is comparable with that of the green sepals.High resolution imaging of petal surfaces of short-lived flowers of C.spinosa, obtained by using scanning electron microscopy,revealed stomata on the adaxial epidermis on both the white and the green parts of the variegated petals;while dense hairs were found on the surface of the abaxial green parts of the variegated petals.Adaxial,epidermal cells of the variegated petals,viewed using atomic force microscopy,possess a submicron,cuticular microfolding that differs between the white and the green parts of the petals.It appears that microridges on the adaxial,white parts of petals of C.spinosa compensate for an increase in cell surface area of the short lived petals,while the roughness of the green parts of petals was found to be higher than that of the white parts.Thus,the micromorphology of surfaces of epidermal cells is expected to affect optical properties and wettability of the floral tissues.These findings may be particularly important for understanding the performance of the short-lived petals of C.spinosa,which are exposed to dryland environments.     

西北山川秀美建设区的可持续发展与引入绿色GDP 核算的设想

在回顾总结西北山川秀美建设区的生态环境的现状与面临的主要问题的基础上,提出了"山川秀美"工程可持续发展运行机制的涵义和应坚持的基本原则,指出"山川秀美"工程建设可持续发展运行机制的建设和健全,有利于维护、改革和完善现存的山川秀美体制,并确保山川秀美工程的健康运行.在这一过程中,引入绿色GDP核算指标不仅能为山川秀美建设区自身的可持续发展、避免重走过去资源为代价的老路超到指导作用,而且对于新形势下国家建立绿色GDP核算指标的工作很有裨益和借鉴,值得我们进行深入地研究和探索.     

新疆棉花膜下滴灌技术的发展与完善

新疆棉花膜下滴灌技术发展经历了试验研究、示范推广和大面积应用三个阶段。"密、早、膜、矮、壮、高"栽培体系的建立等阶段性成果有力地保证了棉花膜下滴灌技术的应用推广;因地制宜、多种毛管田间布置模式的发展适应了棉花种植方式的多样性;对棉花膜下滴灌水分蒸散特征、干旱诊断技术的深入研究为制定灌溉制度和进行科学的水分管理提供了依据,保证了膜下滴灌技术的高效应用;施肥推荐系统和水分自动控制系统的应用增强了棉花膜下滴灌管理的目标性;各级职能部门的重视有力地推动了膜下滴灌技术的发展。当前棉花膜下滴灌技术需解决主要问题有:加快膜下滴灌技术普及与培训;加大对膜下滴灌技术推广的政策扶持力度,调整水价,努力实现经济效益、社会效益和生态效益的统一;继续深入研究棉花膜下滴灌灌溉制度和施肥技术,提高肥水利用效率;加强地下滴灌技术研究。     

水稻白叶枯病抗性遗传力配合力的初步分析

 1978-1981年用12个品种(系)、共30个组合,其中包括国际公认的抗性品种IR₂₆、IR₃₆,观察这些代表品种杂交后代对白叶枯病抗性的遗传力和配合力。结果指出:(1)抗性的广义遗传力较高,相对遗传进度进展较快,表明抗性可早代选择;(2)抗性的一般配合力方差达极显著水准,且GCA:SCA的比值较高,显示加性基因占优势;(3)亲本一般配合力效应方向明显。抗性亲本为负值,感病亲本为正值;(4)特殊配合力效应有正有负,方向性不明显;(5)抗性亲本一般配合力方差较大,特殊配合力方差较小,证明抗性亲本品种有较稳定的遗传效应。以上结果对抗病育种正确选配亲本将有一定意义。     

Relationships between stem canker, stolon canker, black scurf (Rhizoctonia solani) and yield of potato (Solanum tuberosum) under different agronomic conditions

Relationships between diseases caused by Rhizoctonia solani on different parts of potato plants ( Solanum tuberosum ) at different stages of crop growth were investigated under selected agronomic conditions. The effects of different densities of tuber-borne inoculum, date of planting, irrigation, size of seed tubers and their interactions on the incidence of stem and stolon canker during crop growth, the incidence and severity of black scurf and the yield of progeny tubers at harvest were quantified in a multifactorial experiment. Differences in the incidence of stem canker, stolon canker and black scurf were dominated by the effect of density of inoculum on seed tubers at planting. Highly positive correlations between the disease variables indicated a close relationship between the incidence of disease at each stage of crop growth although the degree of association between variables measured at an early growth stage and those measured at progressively later stages of crop growth weakened as the time interval increased. Total yield of progeny tubers was not affected by the density of tuber-borne inoculum although there was a shift in the size distribution, with a decrease in the yield of main-sized tubers and an increase in the yield of baker- and oversized tubers at the higher density of inoculum. Of the remaining factors, the effect of season tended to be more pronounced than any of the agronomic treatments although the use of irrigation and later dates of planting did influence the incidence of infection to a limited extent.     

黑河流域土地覆盖变化与生态环境退化过程分析

本文利用 1 988年、1 995年和 2 0 0 0年三个时相卫星遥感数据 ,对黑河流域土地利用 /覆盖变化进行动态分析 ,综合野外调查和历史资料分析 ,上游地区森林砍伐、植被破坏导致水资源减少 ,中游地区滥用水资源造成土地盐碱化 ,下游地区水资源不足土地沙漠化。水资源问题是黑河流域生态环境退化的关键因子。     

从沙尘暴降尘中元素的富集因子追踪元素的来源及对环境的影响

采用中子活化法和X射线吸收-沉降法对发生在中国甘肃武威地区的一次沙尘暴降尘中的29种元素的含量进行了分析,并分别以此次沙尘暴源区、传输过程中经过地区的不同土壤类型的元素背景值为参考,分别计算了沙尘暴降尘中29种元素的富集因子,研究了不同土壤类型间元素富集因子的相关性,探讨了各元素的主要来源:元素As,Br,Ca,Cr,K,La,Sm,Ta,U,W,Zn的富集因子均大于2,说明它们可能有外来源。外来源主要是由采矿等人类活动造成。过量的这些元素随风迁移并沉积有可能污染环境并产生危害;元素Ce,Co,Cs,Dy,Fe,Mn,Na,Rb,Sc,Tb,Th,Ti,V,Yb的富集因子均接近于1(0.8～2),说明这些元素主要来自自然界本身,而且性质较稳定;元素Eu,Mg,Hf的富集因子均小于0.8,说明这些元素可能随水平移或向土壤深处下移。研究结果可作为沙尘暴对环境的影响的科学依据。     

石羊河流域生态风险敏感性因子的确定

本文从风险的角度对石羊河流域日益恶化的生态环境问题进行了探讨。首先 ,在系统定性分析的基础上 ,将石羊河流域生态风险分为水资源短缺风险及土壤和植被破坏风险 ,并建立了相应的风险指标体系。然后 ,对流域内 6个行政分区的风险因子值进行了获取工作。针对石羊河流域的实际资料 ,采用主成分分析法和改进的灰色关联度法对风险因子进行筛选 ,最终确定出敏感性风险因子 ,为进一步进行风险评价奠定了基础 ,同时也为制订风险的防范措施和对策提供了理论依据。     

干旱区生态环境制图的理论与方法 --以土地荒漠化图为例

土地荒漠化制图是生态环境专题制图的前沿领域，按照现代制图学的原理和土地荒漠化的分类体系，综合制图区域自然及人文要素的时空特征，应用遥感与GIS相结合的方法，编制了不同时期的专题类型图。新技术的应用，反映了信息化时代数字制图技术在土地荒漠化专题制图中的应用潜力，极大地丰富了专题制图学的内涵。同时，体现了专题地图高度的灵活性和强大的选择性，良好的现势性及动态性，制图过程的智能化及制图载体的多样化。本研究重点讨论了荒漠化类型的制图综合，专题要素的表现手法以及制图过程的数据挖掘等关键问题。     

湖南省南方水稻黑条矮缩病毒分离物组分S10编码的ORF序列克隆与分析

采用RT-PCR方法扩增并克隆了2013年湖南省水稻上发生的南方水稻黑条矮缩病毒(Southern rice blackstreaked dwarf virus,SRBSDV)S10片段的近全长序列,采用生物信息学软件Mega、RDP和DnaSP分析其编码的开放阅读框(open reading fragment,ORF)遗传多样性。结果表明:2013年湖南省15个SRBSDV分离物S10编码的ORF序列同源性在99.5%以上,不同分离物中存在3~30个突变位点,绝大部分的核酸突变为无义突变,没有发现可能的重组。在系统发育树上,15个分离物聚类为2个分支,其中湖南汉寿的10个分离物和永州的2个分离物(HuNyz12和HuNyz29)与我国浙江分离物聚为1个亚组、湖南永州的其他3个分离物与我国南部的云南、海南等及越南的分离物聚为1个亚组。系统发育结果表明,SRBSDV随传毒介体白背飞虱迁飞从我国南部向北部扩散。     

莎稗磷对水稻生理生化特性的影响

通过盆栽试验,探讨了莎稗磷施药量、施药时期、施药时的水层深度对不同水稻品种生理生化特性的影响。结果表明：在供试水稻品种中施用莎稗磷会导致水稻的叶绿素含量和根系活力降低,诱导水稻体内的GSH含量、GST活性和SOD活性的提高;在同一品种中,随施药量增加,GSH含量、GST活性先升高后降低,而SOD活性持续增加;缓苗后施用莎稗磷,水稻GSH含量、GST活性和SOD活性提高幅度高于缓苗前施药;施药时保持4 cm水层（未没过心叶）对水稻GSH含量、GST活性和SOD活性的提高幅度低于保持8 cm水层施药（没过心叶）。初步明确水稻东农419对莎稗磷的敏感性高于绥粳4号。     

林业碳汇核证减排量所有权归属的实践样态与应然思路

林业碳汇核证减排量是应对气候变化领域的新生事物,其所有权归属是确保林业碳汇交易稳定的首要问题,但我国《民法典》物权编、自然资源法和碳排交易规范中均无明确规定,个别部门规章对其收益分配的规定有违上位法。实践中各类林业碳汇项目核证减排量所有权归属情形不尽一致的原因是多方面的:林业碳汇权利与采矿权、渔业权产生机理一致,依据土地和森林资源所有权这些"母权",核证减排量可归属的主体众多;我国森林资源用益物权体系结构复杂,搭建了多种归属路径;国际规则下林业碳汇项目参与主体多数涉外,加剧了归属随意化的趋势。在我国鼓励积极开展碳汇交易和推进法规制度建设的背景下,应尽快完善相关法律规范,将核证减排量"类型化"为自然资源性权利客体,圈定所有权归属主体范围,确定国家对核证减排量的管理者角色,确立同一项目核证减排量由多个参与主体共有的制度,遵循自愿公平原则合理分配转让收益,以及做好相关权属争议解决的法律准备。最终为拓宽放活经营权渠道,保障各方利益,乃至我国资源安全和气候安全提供法律支撑。     

不同灌溉量下春小麦土壤水分变化规律

研究了不同灌水量处理条件下春小麦土壤水分变化规律。结果表明:不同灌水量处理下土壤含水率在垂直方向上的变化规律一致,随着深度的增加,土壤含水率变异系数逐渐变小;在春小麦整个发育期,不同灌水量处理在拔节期耗水强度均达最大值,为其需水高峰期;从节水效益看,全生育期灌水量为428.6 mm的处理水分利用效率和灌溉水利用效率较好,灌溉效果最佳,达到节水灌溉效果。     

不同基因型小麦麦茬对杂草的化感抑制作用

采用改进的田间抑制圈生物测定方法,分析了10种不同基因型小麦材料麦茬对杂草生长的影响.结果表明,不同基因型之间以及同一基因型的不同材料之间对杂草的影响均呈现显著差异,说明化感作用基因在稳定遗传的同时存在一定的变异.以现代品种"丰产3号"麦茬地杂草的生物量为对照,其他小麦品种麦茬对杂草均有一定的抑制作用;对10个小麦品种麦茬地杂草的生物量与残茬滞留时间(天)逐步回归分析发现,杂草生长与时间存在明显的正相关关系,其中小麦残茬抑制杂草生长的化感作用有效天数为3～29天,而后杂草生物量逐渐增大,最后达到稳定;染色体组型为AA、AABB及AABBDD的麦茬化感抑制作用均随残留时间的变化而逐渐减弱,抑制杂草的平均有效期分别为21、24和25天,说明小麦在从二倍体到四倍体到六倍体的染色体组变异与倍体变化的长期进化过程中,小麦的遗传可塑性可能有助于化感作用的增强.     

苦豆子内生真菌对宿主培养物生长及喹诺里西啶类生物碱合成的影响

利用苦豆子健康植株中分离鉴定的8株内生真菌菌株为真菌诱导子,分别制备灭活菌丝和菌液浓缩物,研究内生真菌诱导子不同种类、浓度和诱导时间对苦豆子无菌苗和愈伤组织的生长以及喹诺里西啶生物碱含量的影响。结果表明:8株苦豆子内生真菌诱导子中,菌液浓缩物的诱导效果要强于灭活菌丝。菌株HMGKDF1菌液浓缩物和灭活菌丝都能明显促进愈伤组织的生长,净生长率是对照的1.82和1.42倍;菌株NDZKDF13菌液浓缩物对愈伤组织生物碱的合成效果明显,生物碱含量为0.5483 mg·g-1,是对照的23.8倍;在一定浓度范围内(0.01~1.0 mg·L-1),苦豆子内生真菌诱导子能够促进宿主植物喹诺里西啶生物碱的合成。内生真菌诱导子处理苦豆子无菌苗12 d时,喹诺里西啶生物碱含量最高,是对照的2.65倍。在苦豆子无菌苗或愈伤组织中添加一定量的苦豆子内生真菌诱导子,对宿主的生长以及提高喹诺里西啶生物碱含量是一种有效的方法。     

基于网格水文单元的流域水资源自然再生能力评价

首先,从水资源自然再生能力的基本概念探讨入手,提出了一种网格水文单元水资源自然更新率概念,用以表证该网格水文单元的水资源自然再生能力;在此基础上,建立了一种全新的水资源自然再生能力评价方法。其次,在基于GRID的泾河流域水量动态平衡模拟基础上,通过逐网格计算泾河流域1996年各月水资源自然更新率,来对泾河流域1996年水资源自然再生能力进行评价。评价结果表明:泾河流域水资源自然再生能力在年内时间尺度上存在明显的准周期运动规律。泾河流域水资源自然更新率在-1.5到1.5之间,4月为最低值,6月为最高值,整个趋势受降水量的影响较大,丰水期与枯水期差别明显。与此同时,泾河流域水资源自然再生能力也存在明显的空间分布规律,具体表现为泾河流域中部的水资源自然再生能力最高,流域南部地区中等,流域北部水资源自然再生能力较弱。水资源的这种空间分布规律主要取决于该流域降水、蒸发,以及植被与土壤等下垫面空间分布规律。     

Aspects of carbon metabolism and the prospects for enhancing yields

The productivity of a given area of land depends on the amount of light falling on that area, the area of plant available to intercept the light, and a series of factors reflecting the varying efficiency of partial processes of photosynthesis. These factors include the rate of flux of carbon dioxide into the leaf, photochemical events, carbon fixation, dark respiration, photorespiration, partitioning and other metabolic events which together determine the net assimilation rate. In addition, productivity is decreased by lack of nutrient or water, disease and other stresses induced by the environment. As a result, the efficiency of trapping of solar energy into agricultural products is often less than 1% when expressed in terms of the total incident energy available. This contrasts with a theoretical efficiency of about 10% for carbon dioxide assimilated into carbohydrate, and a potential productivity of about 5% for most temperate plants. On the basis of current knowledge of carbon metabolism, the relative importance of some of the above factors in reducing the high initial rates of carbon assimilation to cause low final yields, are assessed.     

Mechanism of action of asulam in celery tissue cultures

The mechanism of action of the phenylsulphonyl carbamate herbicide (asulam) was examined in celery tissue cultures to see whether the mechanism involved an inhibition of folic acid synthesis. When asulam was included in the nutrient medium, growth of the celery cultures was reduced but not entirely inhibited even at a concentration of 250 μm . Growth was also reduced if a phenylcarbamate herbicide (barban), or sulphanilamide were included in the medium. The addition of folic acid, or 4-amino benzoic acid, which is a precursor of folic acid, almost totally reversed the inhibitory effect of the asulam and sulphanilamide, but not of barban, whereas the addition of thymidine, methionine, serine or adenine, all of which are formed from folic acid, did not reverse the inhibitory effect of asulam, sulphanilamide or barban. Nevertheless the removal of the growth inhibition of asulam by folic acid or 4ABA suggested the mechanism of action of asulam was similar to that of a sulphanilamide. This mechanism of action in celery cell cultures appears to be similar to that found for asulam in intact plants of a range of species.     

中华六索线虫生态学研究

本文对中华六索线虫的生物学及一些基本的生态学方面进行了研究。提出了六索线虫寄生粘虫的主动侵染的有关证据。研究结果还表明其群体在土壤中的栖息深度主要在20—40cm处,没有明显的季节性垂直迁移;土壤含水过多,偏酸偏碱以及盐渍化等对其存活都有明显的影响;对寄生率影响较明显的为侵染期的降雨日数和前一年线虫脱出高峰期的露日数。     

Influence of thymic preparations on the result of experimental infection with Taenia crassiceps (Zeder, 1800) in ICR mice

Thymalin (Thymarin) and T-activin--thymic preparations of polypeptidic character--were used for influencing the parasitic infection in a model system mouse--Taenia crassiceps. A single subcutaneous application of 100 micrograms of Thymalin per mouse at the day of infection resulted in a decrease (by 54.9%) in the number of cysticerci in peritoneal cavity of experimental mice compared with the controls. Administration of Thymalin with T. crassiceps larval homogenate at various intervals before and after infection resulted in a statistically significant increase of the level of specific antibodies in the serum of infected mice, this increase, however, did not correlate with the corresponding protective effect. Immunosuppressant azathioprine, injected subcutaneously from 7th to 3rd day preceding infection at a dose of 100 micrograms resulted in a significant increase in the number of T. crassiceps larvae in the peritoneal cavity of experimental mice compared with the controls (by 48.7%). T-activin, injected subcutaneously to mice, immunosuppressed by azathioprine, led to a restoration of resistance of mice to T. crassiceps infection. Subcutaneous application of T-activin alone had a significant protective effect (decrease in cysticerci number by 53.7% in comparison with the controls). Correlation of the level of specific antibodies in the serum of infected mice, value of spleen index and number of T. crassiceps cysticerci in peritoneal cavity of mice was not detected.