不同种植模式和密度对Z1112产量及纤维品质的影响

在机采超宽膜3行和6行2种模式和不同种植密度处理下,对早熟陆地棉品种Z1112的生育期、农艺性状、产量及纤维品质进行比较。结果表明：在机采棉3行13.5万株·hm^－2密度下,籽棉产量为4 999.5 kg·hm^－2,单株个体优势最强,生育期最短为134 d,随着种植密度的增加,单株果枝数、单株结铃数、铃重明显降低,而第一果枝始节位、衣分、纤维品质等性状随密度变化差异较小;6行18.0万株·hm^－2条件下,籽棉产量最高为5 548.5 kg·hm^－2。     

不同密度及整枝方式对棉花品种（系）产量的影响

为探索适宜黄河流域简化整枝的棉花品种（系）及其密度，采用裂区设计，以株型有明显差异的2个品种（sGK中3017和鲁棉研28）以及1个品系（YB60-2）为试验材料，研究其在4个种植密度（4.5万、9.0万、13.5万和18.0万株·hm^－2）和2种整枝方式（常规整枝和简化整枝）下的产量变化。结果表明：在黄河流域，鲁棉研28在密度为4.5万～9.0万株·hm^－2时、sGK中3017在密度为9.0万株·hm^－2时，适于采用简化整枝。     

中棉所100免整枝高产栽培技术探讨

中棉所100是2016年通过国家审定的转基因抗虫棉新品种。2016―2017年对中棉所100进行了不同的栽培密度和整枝方式探讨。结果表明，中棉所100是一个易于管理的棉花品种，在4.50万株·hm^－2、6.75万株·hm^－2、9.00万株·hm^－2、11.25万株·hm^－2的种植密度下，均可以获得较高的产量；在9.00万株·hm^－2的种植密度下，减少整枝或者不整枝，均可以获得较高的产量，并且产量和纤维品质相关性状变化均不显著。     

鄂杂棉30麦后直播高效栽培技术研究

为探寻鄂杂棉30麦后直播的适宜种植密度和施氮量,在见花一次施肥的基础上,采用裂区设计,以密度（60 000株·hm^－2,75 000株·hm^－2）为主区,氮肥施用量（135 kg·hm^－2,195 kg·hm^－2,255 kg·hm^－2）为副区,研究了鄂杂棉30产量及其形成过程。结果表明,各处理平均实收籽棉产量达到3 148 kg·hm^－2,皮棉1 269 kg·hm^－2,其中D1N2（60 000株·hm^－2,195 kg·hm^－2）产量最高,分别为3 331 kg·hm^－2和1 344 kg·hm^－2。但各处理间产量无显著差异,说明该品种具有较强的群体调节和肥料适应能力,在迟播、增密条件下所试验的密度和肥料水平范围内都能获得较高产量。     

不同种植密度对新疆棉花产量及纤维品质的影响

本研究旨在为新疆地区进一步探索提高棉花产量、降低生产成本、提高棉花机械化生产水平,提供可靠的科学依据。以新陆中76号为供试棉花品种,研究不同种植密度（7.5万、10.5万、15.0万、18.0万、22.5万、25.5万株·hm^－2）对其农艺性状、产量及纤维品质的影响。结果表明：随着种植密度的增加,棉花生育期延长,株高与始果枝节位高度越高,单株主茎叶片数、果枝、蕾、花、铃越少,铃重越轻;棉花种植密度以15.0万株·hm^－2,棉花的铃重、衣分、籽棉和皮棉产量最高,其次是18.0万株·hm^－2;密度对纤维长度影响较小,高密度栽培时断裂比强度下降,马克隆值变小。早中熟棉花品种的种植密度在15.0万～18.0万株·hm^－2之间为宜。     

不同密度及整枝方式对苗蕾期无头棉产量及品质的影响

2016年以德棉16号为试验材料,采用裂区设计,在山东省德州市研究了种植密度（3.0万、6.0万和9.0万株·hm^－2）和整枝方式（有头不留叶枝、无头留1个叶枝、无头留2个叶枝和无头留3个叶枝）对苗蕾期无头棉产量的影响。结果表明：在黄河流域,德棉16号在密度为3.0万、6.0万、9.0万株·hm^－2条件下,苗蕾期无头棉分别以留3个叶枝、留2个叶枝和留3个叶枝为宜。     

黄土高原植棉区实现7 500 kg·hm－2籽棉产量的栽培模式探讨

通过对新疆7 500 kg·hm^－2籽棉范例的气候特点、产量结构、管理模式与山西棉花生产的生态环境和资源特点的比对,以及多年棉花高产试验结果分析表明：黄土高原植棉区植棉密度9.0万～13.5万株·hm^－2,总成铃最多只能达到112.5万个·hm^－2左右,在目前生产条件下,再想增加单位面积成铃数难度较大;要想棉花再高产,铃重是产量的决定因素。针对黄土高原棉区光热资源特点,提出通过选用大铃品种,调节株行距配置,提高第1、第2节位成铃率,培肥地力,同步运筹水肥,增加叶面营养和调节剂的应用等措施提高棉花铃重,形成“大群体、小个体、高铃重”的7 500 kg·hm^－2高产栽培模式。     

不同栽培措施对棉花产量及纤维品质的影响

以中棉所89、鲁棉研28为材料,采用再裂区设计,研究了试验材料在2种播种方式（地膜覆盖播种、露地直播）、2种整枝方式（常规整枝和简化整枝）和3个种植密度（4.5万、9.0万和13.5万株·hm^－2）下的产量和纤维品质的变化。结果表明：中棉所89适宜地膜覆盖播种,在密度为9.0万株·hm^－2时进行简化整枝;鲁棉研28适宜露地直播,在密度为4.5万株·hm^－2时进行常规整枝处理。     

淮北生态区短季棉种植经济效益比较分析

2014－2016年连续3年对安徽省淮北生态区种植短季棉与种植玉米或大豆的投入产出情况进行了比较分析。结果表明：种植棉花（短季棉）的单位面积总产出为18 245元·hm^－2，高于种植玉米或大豆等粮食作物。但种植棉花的物化成本为7 050元·hm^－2，比种植玉米多3 000元·hm^－2，比种植大豆多4 275元·hm^－2；劳动力成本为18 900元·hm^－2，比玉米生产多9 300元·hm^－2，比大豆生产多11 700元·hm^－2。种植棉花的纯利润为－8 575元·hm^－2，比种植玉米纯利润低9 805元·hm^－2，比种植大豆纯利润低10 630元·hm^－2；种植棉花的投入产出比为1︰0.68，低于种植玉米或大豆的投入产出比。根据比较分析结果，提出了降低棉花生产成本、提高植棉总产出的技术措施。     

鄂北植棉区麦后直播棉主要栽培技术研究

为探索鄂北植棉区麦后直播棉适宜品种、种植密度、氮肥用量,于2018年在襄阳市南漳县进行了3个独立的单因子5水平大田试验。结果表明：晶华棉116产量最高。ZD2040纤维品质最优,晶华棉116其次。晶华棉116 在施氮肥150 kg·hm^－2 下产量最高,在施氮肥120 kg·hm^－2 下其次。综合分析来看,鄂北植棉区麦后直播种植宜选用铃重适中、衣分较高的早熟和中早熟优质品种,种植密度在6万～7万株·hm^－2,氮肥用量不超过150 kg·hm^－2,可以获得较高的产量和经济效益。     

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.     

马铃薯试管苗组织培养及微型薯诱导技术的研究

通过加入不同浓度的BA、NAA和KT,以探讨外源激素对马铃薯试管苗生理性状的影响,发现低浓度的外源激素较适合用来进行试管苗的增殖。本试验利用香豆素进行微型薯的诱导,结果表明低浓度的香豆素对提高薯重和大薯率有利,而高浓度有利于提高微型薯的结薯数量。     

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.     

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.     

玉米耐盐性研究进展

综述了玉米耐盐生理机制和耐盐育种的研究进展。     

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。