艾氟迪和缩节胺不同处理对黄河流域棉花产量的影响

为简化化学调控,探索适宜的棉花化学调控方式,分别在棉花生育期内施用艾氟迪(AFD) 1次、2次、3次和缩节胺（DPC）3次,研究其对棉花产量的影响。结果表明,分别喷施AFD 3次和2次的处理,棉花花铃期棉铃脱落率较低;AFD 2次化控的处理较对照铃重显著提高,皮棉产量较其他处理亦有一定的提高;同时AFD化控对纤维品质影响不大。因此,在黄河流域棉区应用 AFD进行2次化学调控是较为适宜的化控方式。     

棉花化学调控对不同品种的作用效果

通过棉花化学调控对不同品种反应程度,比较海岛棉血统品种（系）、新疆棉花品种（系）和辽棉品种（系）等在相同化学调控条件下的综合表现,结果表明：不同棉花品种（系）对化学调控的反应有明显差别,具有海岛棉血统棉花品种（系）反应不敏感,新疆棉花品种（系）反应较敏感,辽棉品种（系）属于中间类型。同时,化控对于新生的器官影响较大,也印证了化控药剂在植株体内有一个吸收和分解的过程。     

浙江省棉田化学使用技术

浙江省棉花“三化”栽培技术是以“三化”（即全程化学除草、化肥促控、化学调控三项技术）为核心，配套其它相应增产技术而成的一项实用综合高产技术。１９９５～１９９７年该技术在本省的慈溪、上虞、萧山、余姚、平湖、海盐６个主产棉县（市）的５７个乡（镇）推广应用...     

生长调节剂在棉花生产上的应用

生长调节剂在棉花全程栽培中的化学调控,就是在棉花整个生育期内,根据棉花生长发育情况,用植物生长调节剂处理棉花植株,定向调控棉株各器官的生长,改善其生理功能,起到调壮控旺、催熟增产的作用,最终实现棉花优质高产.目前在生产上广泛应用、成效显著的生长调节剂是乙烯利和缩节胺.     

不同棉区棉花栽培密度与化学调控技术

0引言化学调控技术是提高作物生产力的一项重要技术资源,是在棉花生长发育的不同阶段,根据气候、土壤条件、种植制度、品种特性和群体结构的要求,连续数次使用缩节胺(DPC)进行定向诱导,以塑造理想株型[1,2]。虽然目前棉花全程化学调控技术日趋完善,但随新品种选育及生产条件的改善,调控技术指标都应随     

甲哌嗡片剂对棉花全程精确调控技术

甲哌嗡对棉花全程精确调控是一种高效、稳妥的化控技术,是缩节胺应用技术的拓展,弥补了传统缩节胺调控技术的一些不足,属于全新的棉花全程精确调控技术。本文概述了12.5%甲哌嗡片剂对棉花全程精确调控的效果,介绍了棉花实施全程化控技术要点。     

缩节胺在棉花生产上的应用研究概述

缩节胺(DPC)是一种外源的植物生长调节剂,它可以调控作物的生长发育、长势和成熟性,在中国不同生态类型的棉田均有应用。通过总结前人的研究成果,概括了缩节胺化学调控技术在棉花生产中的应用现状,分析了缩节胺化控对棉花早衰及产量和品质的影响。     

湖北仙桃市棉花化学调控技术存在的问题及对策

棉花化学调控技术较好地解决了肥促与疯长、疯长与坐桃的矛盾,协调了密、肥、水与成桃的关系,是棉花高产优质综合配套不可缺少的关键技术措施之一,已成为棉花生产的一项必不可少的技术。然而在生产中也出现了一些问题,致使效果不理想。笔者就仙桃市棉花化学调控技术中存在的问题及解决的途径浅析如下：     

化学调控与棉花成铃分布试验报告

棉花经过化学调控，其成铃分布在时间和空间上有着极显著的差异。以在盛蕾、初花、盛花，打预后进行３～４次化控，效果较好。     

棉花化学调控技术研究进展

化学调控是当今棉花高产、高效、优质栽培模式研究的热点之一,在定向调控棉花群体的生长发育,改变传统的整枝、中耕等单一调控措施以及对表现型性状的修饰等方面具有重要作用。重点综述了近年来化学调控条件下棉花根系、植株农艺性状、叶片光合性能、植株体内酶活力以及棉花产量和品质的变化特征,阐明化学调控对棉花生长的定向调控作用和效果,并就化学调控技术与理论的完善及未来发展方向进行了展望。     

兜兰离体快繁技术研究进展

由于生境破坏和人工过度采挖及繁殖的障碍,兜兰已是世界上最濒危的植物物种之一,所有野生种均被列入《濒危野生动植物种国际贸易公约》附录I而被禁止交易。突破其种苗繁殖技术瓶颈有利于兜兰种质资源的保护和可持续利用。本文对兜兰属植物无菌播种、共生萌发和组织培养技术等离体快繁技术的进展进行综述,并提出了目前存在的问题和解决方法,以期为兜兰属植物离体繁殖技术的深入研究和优质种苗的规模化生产提供参考。     

High variation in frequency of infection by endophytes in cultivars of meadow fescue in Finland

Systemic and asymptomatic Neotyphodium fungal endophytes infect numerous species of the Poaceae. The frequencies of Neotyphodium endophyte infection in Finland were investigated among and within seven Nordic cultivars of meadow fescue, Schedonorus pratensis (Huds.) P. Beauv., which is a widely grown pasture and forage grass species in Scandinavia. The cultivars were Kasper, Salten, Antti, Fure, Ilmari, Inkeri and Kalevi. Frequencies of infection of cultivars varied from endophyte-free cultivar Fure to highly infected cultivar Inkeri [mean (standard deviation of mean) of 0·95 (0·023)]. Mean frequencies of infection of three cultivars remained lower than 0·10, and two of the cultivars, Kasper and Salten, were intermediately infected. In most of the cultivars, frequencies of infection varied only slightly among seed lots. In cultivar Kasper, however, the frequency of endophyte infection was highly variable (0–0·96) among the 45 seed lots examined. The relative importance of cultivar, seed lot and infection by Neotyphodium endophyte to the aphid Rhopalosiphum padi L. was studied experimentally, using both endophyte-free and endophyte-infected plants of four seed lots of the two intermediately infected cultivars. Endophyte infection increased plant resistance to R. padi , overriding the influences of seed lot and cultivar. It is proposed that variation caused by endophyte infections in cultivars of meadow fescue should be taken into account in assessing plant breeding programmes in Europe.     

Investigation of Polymorphisms in Coding Region of OsHKT1 in Relation to Salinity in Rice

Rice(Oryza sativa) is sensitive to salinity, but the salt tolerance level differs among cultivars, which might result from natural variations in the genes that are responsible for salt tolerance. High-affinity potassium transporter(HKTs) has been proven to be involved in salt tolerance in plants. Therefore, we screened for natural nucleotide polymorphism in the coding sequence of Os HKT1, which encodes the HKT protein in eight Vietnamese rice cultivars differing in salt tolerance level. In total, seven nucleotide substitutions in coding sequence of Os HKT1 were found, including two non-synonymous and five synonymous substitutions. Further analysis revealed that these two non-synonymous nucleotide substitutions(G50T and T1209A) caused changes in amino acids(Gly17Val and Asp403Glu) at signal peptide and the loop of the sixth transmembrane domain, respectively. To assess the potential effect of these substitutions on the protein function, the 3D structure of HKT protein variants was modelled by using PHYRE2 webserver. The results showed that no difference was observed when compared those predicted 3D structure of HKT protein variants with each other. In addition, the codon bias of synonymous substitutions cannot clearly show correlation with salt tolerance level. It might be interesting to further investigate the functional roles of detected non-synonymous substitutions as it might correlate to salt tolerance in rice.     

用蛭石做马铃薯快繁培养基支持体的初步研究

1　前　言目前 ,马铃薯脱毒快繁技术已广泛应用于科研与生产中 ,快繁过程中脱毒苗培养基支持体通常采用琼脂或直接采用液体培养。然而这两种培养基存在着诸多问题 ,例如琼脂培养基中的琼脂价格昂贵、成本高 ,而且胶体不利于营养物质的扩散、透气性差 ,导致瓶苗生长不良。因此 ,该实验在本着降低成本的同时 ,又能保证瓶苗正常生长的前提下 ,以蛭石代替琼脂 ,分析其在实际生产中的应用价值。2　材料与方法2 1　材料供试品种为郑薯 6号脱毒苗 ,试验于 2 0 0 2年在郑州市蔬菜研究所马铃薯脱毒实验室内进行。2 2　方法本试验设两个处理 :处理 1…     

Matlab在玉米子粒灌浆特性分析中的应用

利用Matlab软件对玉米子粒灌浆过程用Richards方程进行拟合后,通过编程实现灌浆次级特征参数计算,并对不同播期子粒灌浆特征进行分析和探讨。结果表明,在黑龙港地区生态条件下,不同播期玉米各部位子粒灌浆均符合"S"形生长曲线,可用Richards方程很好地拟合。不同播期条件下,早播处理子粒起始势最高,达到灌浆盛期时间最早,平均灌浆速率及最大灌浆速率最大,活跃灌浆期较长,粒重最高。各播期玉米不同部位子粒,穗下部与上部相比,子粒的起始生长势较大,平均灌浆速率较高,达到灌浆高峰期时间较短,粒重较高。     

5个马铃薯品种组培幼苗的磷效率差异研究

试验以5个生产用马铃薯品种脱毒试管苗为材料,采用组织培养的方法,初步研究了茎切段在正常磷及低磷培养基中生长30 d时幼苗的磷营养效率差异,为筛选出适宜于生产用的磷高效马铃薯品种奠定了基础。试验结果表明,5个马铃薯品种幼苗在正常磷和低磷胁迫下对磷素的吸收和利用能力均存在明显的基因型差异。利用各品种幼苗的磷效率指标(植株干重、鲜重、吸磷量、磷利用效率)的相对指标(低磷处理的结果/正常磷处理的结果×100)进行聚类分析(类平均法)的结果表明,大白和I-1035属于磷高效基因型品种,中农Ⅷ是磷低效基因型品种,凉薯97和疫不加则属于中间类型品种。     

植物耐盐性研究进展

盐胁迫损害植物质膜的正常功能,造成植物气孔关闭,光合降低,耗能增加,养分离子吸收不平衡.目前已从许多植物中分离了一些盐胁迫诱导的基因及基因上游序列,但对植物耐盐分子机理尚未完全阐明,主要有渗透调节、拒盐机理、盐的区隔化、钾离子运输调控系统、水通道蛋白和光合途径改变等几种假说,有些耐盐基因已被成功转入植物中.研究表明,添加一些外源物质能提高植物的耐盐性。     

我国发展能源油料作物的策略分析

分析了国内外植物油脂的供需形势、我国耕地和边际地利用潜力、油脂植物资源的种属分布特点等,提出发展我国能源油料作物和生物柴油产业的3点建议：加大对边际地、油脂植物资源的调查等基础平台性研究,为政府决策和产业服务;加强产学研结合,形成研究、推广、产业的良性循环;制定能源植物推广应用优惠政策、推动能源油料作物生产发展。     

Quantitative assessment of metals in local brands of tea in Pakistan

In present study, Mn, Fe, Zn, Cu, Co, Pb, Cr, Ni and Cd were analyzed by FAAS in green and black tea samples of locally available in the Pakistani market. Na and K were also determined by Flame Photometer. Tea leaves can be the source of mineral components and trace elements, as well as some undesirable substances due to exposure to the environment. Among the metals tested, K was the most abundant one followed by Na, Mn and Fe. Fortunately, toxic heavy metals, Pb and Cd, had the lowest contents in tea samples and also in tea aqueous extracts. Concentration of heavy metals in tea aqueous extract was markedly lower than their total contents except that of K. The solubility of studied metals in tea aqueous extract varied widely and ranged from 0.0-95%. The lowest ranges of solubility were listed for toxic heavy metals Pb and Cd. The possible uptake of metals by the human body from tea aqueous extract has also been determined. The amounts of metals that one may take up through consumption of tea aqueous extract were found to match the acceptable daily intake even taking into account exposure from air, food and drinking water.     

Role of invertase in the accumulation of sugars in cold-stored potatoes

Freshly harvested potatoes contain low levels of total invertase and high levels of invertase inhibitor. Total invertase increases sharply when potatoes are placed in cold storage, but the inhibitor is not depleted in all varieties. The absence of basal invertase activity in Norchip tubers indicates that an excess of invertase is not required for reducing sugar formation. Analyses of 37 varieties and seedlings after 3 months cold storage revealed that the reducing sugar content is not proportional to the invertase activity. High sugar contents are associated with low inhibitor levels, but low sugars are not necessarily associated with high inhibitor levels. The results indicate that invertase participates in reducing sugar formation, but other factors are responsible for the regulation of starch-sugar conversion in potatoes during cold storage.