SH系列苹果矮化砧性状及生理特性的研究

SH系列苹果矮化砧是国光与河南海棠种间杂交育成。杂种无性系自根砧嫁接苗于1982年秋定植,嫁接品种为羽红、金冠。经连续7年的生物学特性、物候期等方面的观察研究及一些主要生理指标的测定分析表明,SH系苹果矮化砧嫁接品种比对照M_7和M_9作钻木抗逆性强、进入开花结果期早、成花能力强、早期丰产、果实着色成熟期提前、外观艳丽、风味浓郁、可溶性固形物含量高;并具有萌芽开花期晚,新梢停长、落叶期早,叶片肥厚,比叶重大,叶绿素含量高,净光合效率强,在干旱条件下,叶片水势,气孔阻力大、蒸腾强度小等生理特性。SH系矮化砧已批量繁殖,已在全国10省、市苹果主产区进行区试和推广。     

绿肥苦豆子草中植物生长刺激物质的初步研究

应用生物测定方法,测定了苦豆子草中生物碱的某些植物激素活性.结果表明,喹喏里嗪啶生物碱类具有明显的植物生长刺激作用:促进离体黄瓜子叶的扩张和干物质的积累;促进离体黄瓜子叶根的形成和根的生长.     

Western flower thrips resistance to insecticides: detection, mechanisms and management strategies

Insecticide resistance continues to be one of the most important issues facing agricultural production. The challenges in insecticide resistance and its management are exemplified by the situation with the western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). This highly invasive pest has a great propensity for developing insecticide resistance because of its biological attributes, and cases of resistance to most classes of insecticides used for its management have been detected. To combat insecticide resistance in the western flower thrips, several insecticide resistance management (IRM) programs have been developed around the world, and these are discussed. Successful programs rely on non-insecticidal tactics, such as biological and cultural controls and host plant resistance, to reduce population pressures, rotations among insecticides of different mode of action classes to conserve insecticide efficacy, resistance monitoring, sampling to determine the need for insecticide applications and education to assure proper implementation. More judicious insecticide use is possible with the development of well-founded economic thresholds for more cropping systems. While growers will continue to rely on insecticides as part of western-flower-thrips- and thrips-transmitted virus management, more effective management of these pests will be achieved by considering their management in the context of overall integrated pest management, with IRM being a key component of those comprehensive programs.     

红星苹果矮化自根砧的营养耐旱生理特性

对嫁接在M7、M9、山定子砧木上的红星苹果的叶片解剖结构、叶绿素含量、净光合效率、矿质营养及耐旱性进行测定,结果表明,供试砧木对嫁接品种的叶片厚度、栅状组织厚度、比叶重、叶绿素含量、叶绿素a含量及净光合效率均无显著影响;叶片矿质元素含量,除M9、山定子与M7的B元素外,各砧木嫁接品种的N、P、K、Ca、Mg、Fe、Zn、Mn元素含量均无显著差异:在干旱条件下,山定子比M7、M9砧木耐旱,山定子与M7、M9对嫁接品种蒸腾强度无显著影响,但前者比后者叶片水势大,表现了耐旱的特性。     

Heavy Metal Concentrations in Gray Calcareous Soils of Baiyin Region,Gansu Province,P.R. China

Concentrations of cadmium (Cd), copper(Cu), lead (Pb), zinc (Zn), manganese (Mn) and nickel(Ni) were measured in cultivated gray calcareous soilscollected in the two basins of Baiyin urban area. Thevalues revealed fluctuating and enriched Cd, Pb, Cuand Zn concentrations in the cultivated soils,suggesting recent inputs from anthropogenic sources.There also existed differences between these twodrainage areas, indicating the characteristics ofpollution sources differed. Concentrations of Cd, Pband to a lesser extent Cu and Zn were higher in thisregion as compared with the micrometal backgroundvalues in gray calcareous soil, which may beattributed to the proximity of these soil sites tocontaminated streams, or to the utilization offarmyard manure or fertilizers. Comparison of obtainedmetal concentration levels with other areas in theworld revealed elevated values for Cd and Pb, showinga considerable amount of pollution in the area.Continuous monitoring and further studies of the areaare recommended to ascertain long-term effect that mayhave not yet been reached and to prevent pollution offarmland from worsening.     

杨二尾舟蛾幼虫空间分布型及抽样技术的研究

通过采用种群的聚集度指数：Ｃ、１／ｋ，λ，ｍ√ｘ、Ｌ、Ｔａｙｌｏｒ冥法则和ｍ对ｍ的回归方法测定杨二尾舟蛾幼虫的空间分布型，并用不同的抽样方法比较离抽样精确度，杨二尾舟蛾幼虫在林内呈聚集分布，其聚集的原因是由环境因素所引起，幼虫空间分布的基本成份是个体群，个体间相互吸引，分析证明杨二尾舟蛾幼虫采用平行线和“Ｚ”字型抽样方法误差最小。     

不同稀土元素处理对沙葱种子活力及生理生化特性的影响

以不同贮藏年限的沙葱种子为试材,采用不同浓度的稀土、氯化镧、氯化钇和氯化铈对贮藏2年和5年的沙葱种子进行浸种处理,测定其活力指标、抗氧化酶活性、超氧阴离子(O2·-)、丙二醛(MDA)和维生素C含量,明确不同处理对沙葱种子萌发及生理生化特性的影响,以期为提高种子利用率和保护种质资源提供参考依据.结果表明:不同浓度的药剂处理对沙葱种子的萌发效果不同,低浓度处理能够促进种子的萌发,其中400 mg·L-1氯化铈处理对沙葱种子萌发效果最好.20℃贮藏温度条件下,沙葱种子抗氧化酶活性最高,50℃贮藏温度条件下,氯化铈处理O2·-产生速率和MDA含量与CK相比,显著下降.维生素C含量在35℃和50℃条件下铈离子高于对照.     

沙芥属植物种子研究进展

综述了沙芥属植物种子的形态结构、化学成分、物理特性、形成发育及成熟、休眠与萌发、贮藏与寿命、抗逆性等方面的研究进展,并指出了研究中存在的问题,展望了今后研究的重点,以期为沙芥属植物种子的开发利用和深入研究提供参考.     

SDC系苹果矮化砧木生长、结果及抗逆性的研究

以SDC系苹果砧木为试材,连续9年观察测定了在其上嫁接的红星树早花、早果、产量、果实品质、树体矮化性及抗逆性等生物学特性.结果表明:(1)SDC系砧木嫁接树比M9、M7嫁接树提早1—2年开花结果,幼树期花量密度大,5年生树总花序数及单位树干面积花序数明显高于M9和M7.(2)果皮色素花青苷含量、果肉可溶性固形物含量和总糖量均高于M9和M7,果实外观及内在品质优良.(3)幼树矮化性状明显,树高/冠幅比值小,树冠开张.(4)叶片蒸腾量小.脱落酸(ABA)含量高,单位叶面积失水量小,抗旱性强.(5)嫁接树越冬期枝条自由水含量高,抽条率明显低于M9,越冬能力强.并对SDC系砧木的优缺点进行了讨论.     

A promising amendment for the immobilization of heavy metal(loid)s in agricultural soil,northwest China

Journal of Soils and Sediments - In situ remediation techniques are currently limited for agricultural soil contaminated by heavy metal(loid)s, particularly for alkaline soil. In this study, we...