Tolerance of spring barley (Hordeum vulgare L.), oats (Avena sativa L.) and wheat (Triticum aestivum L.) to saflufenacil

Saflufenacil is a new herbicide being developed by BASF for pre-emergence application for broadleaved weed control in maize and other crops. Three field studies were conducted in Ontario, Canada over a 2-year period (2006 and 2007) to evaluate the tolerance of spring cereals (barley, oats, and wheat) to pre-emergence and post-emergence applications of saflufenacil at 50 and 100 g ai ha⁻¹. Saflufenacil pre-emergence caused minimal visible injury (1% or less) at 3, 7, 14 and 28 days after emergence and had no adverse effect on plant height or yield of barley, oats, and wheat. Saflufenacil plus the surfactant Merge (1% v/v) applied post-emergence caused as much as 76, 60, 52 and 35% visible injury in spring cereals at 3, 7, 14 and 28 DAT, respectively. Injury with saflufenacil plus Merge applied post-emergence decreased over time and was generally greater as dose increased. Saflufenacil plus Merge applied post-emergence reduced plant height by as much as 16% and reduced yield of spring barley and wheat by 24 and 13%, respectively, but had no effect on the yield of spring oats. Based on these results, saflufenacil applied pre-emergence at the proposed dose can be safely used in spring planted barley, oats and wheat; however, the post-emergence application of saflufenacil results in unacceptable injury and yield loss. These results are consistent with the proposed pre-emergence use pattern for saflufenacil.     

Discrimination of weed seedlings, wheat (Triticum aestivum) stubble and sunflower (Helianthus annuus) by near-infrared reflectance spectroscopy (NIRS)

The potential of using near-infrared reflectance spectroscopy (NIRS) to discriminate between seven broadleaf weed species, sunflower and wheat stubble was evaluated. Our results showed that the spectral window between 750 and 950 nm, which corresponds to near-infrared wavelength, was able to discriminate among wheat stubble, sunflower and the most problematic “hard-to-control” weeds in no-till sunflower, i.e. Little mallow (Malva parviflora L.) and Ecballium elaterium L. These results are promising for further work in real-time remote sensing identification of weed patches in sunflower fields.     

Genetic and environmental analysis of NIR feed quality predictions on genotypes of barley (Hordeum vulgare L.)

This study investigated the use of NIR feed quality equations, developed from a multi-cereal calibration set, including barley, on barley breeding lines and commercial cultivars. The resultant predictions were then analysed to ascertain genetic and or environmental affects. The calibrations were developed by a third party, using a NIRSystems 6500 (master) instrument. The barley spectra we used were also from the same model of instrument, which had been spectrally standardised to match the master instrument. The breeding lines and commercial cultivars used were obtained from a field trial series which combined intermediate and advanced breeding lines, grown at 11 environments over two seasons. The results indicated there were significant (P < 0.05) genetic and environmental effects on a broad range of feed quality related traits; including metabolisible energy, digestible energy and apparent metabolisible energy. Other feed traits such as acid detergent fibre, neutral detergent fibre, β-glucan and starch also showed significant (P < 0.05) genetic and environmental affects. There was a high level of heritability for most traits, ranging from 70 to 90%. The results identified a number of strongly correlated traits when analysed by factor analysis. These included starch and the energy traits. There were no strong associations between particular cultivars and the NIR predicted feed traits. The results from this study highlighted NIR equations for predicted feed quality that can provide data to assist selection of barley breeding lines. In addition, the analysis also showed the genetic and environmental effects that could be expected to be observed in a broad range of barley breeding material and commercial varieties. This information can be combined in breeding programs to identify robust barley lines that would be suited to specific animal feed classes.     

大麦单株产量性状的杂种优势及其稳定性分析

为研究不同环境下大麦单株产量性状的杂种优势及其稳定性,以113个(Nasonijo×泰兴9425)DH系配制226个杂交种构建的永久F_2群体及亲本为材料,分别调查参试材料在4个环境下的单株穗数、主穗粒数、千粒重、单株产量和单株生物量,利用方差分析、聚类分析及稳定性分析对大麦单株产量性状的杂种优势及其稳定性进行了分析。结果表明,大麦杂种F_1各被测性状大多表现中亲优势,超亲优势组合出现率相对较低。各被测性状的杂种优势不仅受自身遗传因素影响,而且受试点生态条件及年度气候条件的影响。杂种优势的稳定性因性状不同而异,千粒重和主穗粒数杂种优势的稳定性较好,单株生物量和单株产量杂种优势的稳定性较差,仅有2个组合在多环境下表现出稳定的强杂种优势。     

大麦黄花叶病抗性的遗传分析与QTL定位

大麦黄花叶病是依靠土壤中禾谷多黏菌传播的病毒病,严重影响冬大麦的产量和品质,培育和利用抗病品种是最经济有效的防治方法。本研究以抗病品种扬饲麦1号与感病品种Gairdner为亲本,以杂交F₁代经花药离体培养技术构建的DH群体为材料,对其大麦黄花叶病抗性进行两年鉴定与分析,并利用91对在亲本间多态性好的SSR(simple sequence repeat)标记构建了群体的遗传连锁图谱,采用Windows QTL IciMapping 4.0软件中的完备区间-加性模型（ICIM-ADD）对大麦黄花叶病进行QTL定位,共检测到9个与大麦黄花叶病病情指数相关的QTLs, 其中,qRYM-1Ha、 qRYM-1Hc、qRYM-2Ha 及qRYM-2Hb在两年间均被检测到,且 qRYM-2Ha在两年6个时期均被检测到,位于EBmag0793至GBM1047标记区间内,可解释的表型变异为5.61%～38.04%; qRYM-2Hb在 2015年第二、三期和2016年第一期被检测到,位于GBM1047至Bmag0749标记区间内,可解释的表型变异为11.40%～18.80%。qRYM-1Ha和 qRYM-4Ha可能是两个新的大麦黄花叶病抗性QTLs,黄花叶病抗性基因均来源于黄花叶病抗性品种扬饲麦1号。本研究为大麦黄花叶病抗性基因的发掘、精细定位、基因克隆及分子标记辅助选择育种提供了有利信息。     

Influence of growth temperature on content, viscosity and relative molecular weight of water-soluble β-glucans in barley (Hordeum vulgare L.)

β-Glucan content and viscosity of water-soluble β-glucans have a considerable impact on the digestion of barley. Eight different 2-row barley (Hordeum vulgare L.) cultivars were grown in controlled environment chambers at five different temperatures until maturity. The samples were pearled, milled and analysed for their content of total, insoluble and soluble β-glucan. The water-soluble fraction was extracted at 37 °C, subjected to amylase treatment and freeze-dried. Water-soluble crude β-glucans were solubilised in distilled water, analysed for viscosity and their purity was checked by nuclear magnetic resonance. Molecular weights were profiled by size exclusion chromatography with RI detection. The content of total β-glucan varied from 4.0% to 7.4%, and was significantly affected by the growth temperature. An interaction between cultivar and growth temperature was observed for the total β-glucan content. The extractability was significantly affected by growth temperature, as there was recorded an increasing amount of water-soluble β-glucan with increasing growth temperature. Both the viscosity and the molecular weight of the water-soluble β-glucans increased with the growth temperature.     

青稞法尼基转移酶β亚基编码基因HbERA1的克隆及表达分析

ERA1(Enhanced response to ABA)基因编码法尼基转移酶(Farnesyl transferase)β亚基,该酶在干旱胁迫下对ABA信号负向调控因子的修饰起着关键作用。本研究以青稞(Hordeum vulgare subsp.vulgare)抗旱品种喜马拉雅10号为材料,利用RT-PCR技术克隆获得了ERA1基因全长cDNA序列,命名为HbERA1(登录号:KJ699392)。生物信息学分析表明,该基因全长1 401bp,可编码466个氨基酸序列,蛋白分子量为51.14kD,等电点为5.00。Prosite Scan分析结果表明,HbERA1含有多个干旱胁迫响应蛋白的作用位点,如酪蛋白激酶Ⅱ磷酸化位点、N-糖基化位点、蛋白激酶C磷酸化位点及N-豆蔻酰化位点。利用实时定量PCR方法研究了HbERA1在干旱胁迫条件下及复水后不同时间点的表达情况,发现在水分过剩处理下(土壤绝对含水量15.5%),HbERA1在土壤绝对含水量为33.4%时表达量最高,并随着土壤绝对含水量的下降而下调表达;进行干旱胁迫后(15.5%)基因表达量也明显下调表达;复水后表达逐渐恢复,复水8h时超过正常表达水平,表明HbERA1基因可能参与调控水涝和干旱胁迫双重信号传导。     

外引大麦农艺性状SSR关联位点及等位变异表型效应分析

为了发掘引进大麦携带的优异等位变异,对55份引进大麦材料进行了混合模型（MLM）关联分析和对关联位点等位变异的表型效应进行分析。结果表明,经MLM关联分析,共检测出15个SSR位点与株高、穗长、穗下茎长、千粒重、全生育期等5个农艺性状相关联,其对性状的解释率为3.19%~24.30%,位点GBMS2 和HVM33同时分别与株高、穗长、千粒重等多个性状关联。经表型效应分析,7个位点上的22个有效等位变异中,6个等位变异对穗长、株高和千粒重表现为正向效应,其余对穗长、株高和千粒重表现为负向效应。各等位变异平均效应主要为减效,仅株高、千粒重关联位点的等位变异平均效应为增效。     

基因型和环境对以色列野生二棱大麦籽粒营养品质的影响

为探讨基因型和生长环境对野生二棱大麦营养性状的影响,对源自以色列不同地区的9个群体60个基因型野生二棱大麦材料在3个环境条件下的籽粒可溶性蛋白质、氨基酸、植酸、无机磷和淀粉含量及粒重进行测定,并对检测数据进行了单因素方差分析(One-Way ANOVA)、相关性网络分析(correlation-based network analysis,CNA)和斯皮尔曼秩相关分析(Spearmanp’s Rho Correlation)。结果表明,野生二棱大麦各被测性状与生长地土壤成分存在显著相关性(P0.01);以色列野生二棱大麦籽粒中无机磷、总淀粉含量和粒重受生长环境和基因型的共同影响,而植酸、可溶性蛋白质、氨基酸含量等性状则主要受生长地环境的影响。     

Screening of allelochemicals on barnyardgrass (Echinochloa crus-galli) and identification of potentially allelopathic compounds from rice (Oryza sativa) variety hull extracts

Experiments were conducted to screen 23 known allelochemicals, including sinapic acid, and an equimolar mixture of the chemicals for potential allelopathy on barnyardgrass (Echinochloa crus-galli var. oryzicola), and to identify allelochemical(s) from hull extracts from three rice (Oryza sativa L.) cultivars. In a bioassay, the inhibitory effect was increased as the concentration of allelochemicals increased from 10⁻⁵ to 10⁻³ M. Ferulic, p-hydroxybenzoic, p-coumaric, and m-coumaric acids were the most active compounds and caused the greatest effect on seed germination, germination rate, and total seedling dry weight reduction. p-hydroxybenzoic acid (10⁻³ M; pH 4.1) showed the greatest inhibitory effect on the same parameters. HPLC analysis using three rice cultivars, Janganbyeo, Baekambyeo, and Labelle, showed that the concentration and composition of potentially allelopathic compounds depended upon the cultivar. Hull extracts from the allelopathic cultivar Janganbyeo contained higher levels of p-hydroxybenzoic acid than did those of the non-allelopathic cultivars Labelle and Baekambyeo. Nine compounds, including p-hydroxybenzoic acid (4.29 mg/g) in Janganbyeo, seven compounds including m-coumaric (0.43 mg/g) in Labelle, and five compounds including p-hydroxybenzoic acid (0.36 mg/g) in Baekambyeo, were detected. Preliminary identification by HPLC analysis resulted in peaks with retention times near those of standards, including p-hydroxybenzoic acid that was confirmed with EI/MS. It is suggested that these compounds may be, at least, a key factor in rice allelopathy on barnyardgrass, and the information presented may contribute to the development of naturally occurring herbicides.     

保水剂和施肥量对沙地燕麦生产的影响

为给保水剂在沙地燕麦生产中的应用提供依据,在吉林白城雨养贫瘠沙地条件下,采用完全随机设计,研究了不同施肥水平下保水剂对燕麦秸秆和籽粒产量、品质及土壤养分的影响。结果表明,在4个复合肥（NP₂O₅ K₂O:151515）施用量（375、300、225和150 kg·hm^-2）下,与对照相比,施用保水剂（60 kg·hm^-2）使燕麦平均秸秆产量、籽粒产量、地上部和地下部生物量分别增加38.58%、22.60%、32.02%和24.59%,差异均显著（P<0.05）;叶、茎、籽粒平均粗蛋白含量分别增加0.65、4.09和2.58个百分点,相对饲用价值分别增加13.28、7.6和18.57个百分点;相对增加了耕层土壤养分（全N、速效P、速效K）含量,对0~10 cm土层影响显著。肥料施用量显著影响燕麦秸秆产量、籽粒产量、地上和地下部生物量、植株粗蛋白含量和0~30 cm土层养分含量。施用保水剂可显著提高籽粒产量平均肥料利用效率29.6%。60 kg·hm^-2保水剂和375 kg·hm^-2肥料施用量组合下燕麦产量最高,品质最优。     

Influence of the soil physical environment on rice (Oryza sativa L.) response to drought stress and its implications for drought research

Plant performance under drought stress is not solely defined by an inadequate water supply but by an interaction among many factors, including climatic, edaphic, and biological factors. An important interacting factor affecting root growth, and therefore the ability of a plant to access and take up water, is the soil physical environment. Soil penetration resistance can restrict, or even halt, root system growth. For rice, a soil penetration resistance of 1.4 MPa is sufficient to inhibit root system expansion. This review describes the effects of the soil physical environment on root growth and its interaction with drought stress. A large variation in soil penetration resistance exists among rainfed rice-growing areas of South and Southeast Asia and within experimental stations used for managed-drought field phenotyping. This variability may influence genotypic performance across experimental sites/countries and the response of crop genotypes to drought stress. A case study is presented in which differences in the soil physical environment may partially elucidate differences in experimental results between two field studies conducted at different locations. These results highlight the need for increased knowledge of environmental interactions to allow the outputs of genomics to increase drought tolerance at the field level.     

水分胁迫对不同抗旱性燕麦品种光合及产量形成的影响

为了解水分胁迫对不同抗旱性燕麦品种光合和产量的影响,以抗旱性不同的蒙燕1号和坝莜3号为材料,在拔节期和抽穗期采用防雨棚盆栽方式,测定分析了不同水分处理［重度胁迫（30%田间持水量（FWC））、中度胁迫（45%FWC）,适度控水（60%FWC）和正常供水（CK,75%FWC）］下燕麦叶片叶绿素含量、气体交换速率、叶绿素荧光动力学参数、产量及其构成因素的差异。结果表明,两个燕麦品种叶片叶绿素a含量、叶绿素b含量及叶绿素总含量、净光合速率、蒸腾速率、最大荧光、最大光化学效率（F_v/F_m）、实际光化学效率、光化学猝灭系数均随着水分胁迫程度的加剧而下降,初始荧光与非光化学淬灭系数则呈上升趋势,且水分敏感品种坝莜3号的光合受抑制程度显著大于抗旱品种蒙燕1号。燕麦的光合特性和产量受水分胁迫影响的程度整体上表现为拔节期大于抽穗期。中度和重度水分胁迫下坝莜3号的每穗小穗数、千粒重均下降,而每穗秕粒数显著增加,减产13.9%～25.7%。蒙燕1号的产量在适度控水条件下未显著下降,且水分利用效率较高,而在中度和重度水分胁迫下每穗小穗数和穗粒数均显著降低,导致减产9.1%～23.5%,但其 F_v/F_m和叶绿素a/b值较高;在相同水分条件下蒙燕1号的产量显著高于坝莜3号。这说明在水分胁迫下抗旱性强的燕麦品种的光系统Ⅱ的损伤和光抑制较轻,光合同化能力较强,产量损失少。     

土壤干旱胁迫对白芥光合器官发育及光合速率的影响

利用旱棚盆栽研究了在土壤干旱胁迫下白芥抗旱和不抗旱品系的单叶面积,单株叶面积、出叶速度、叶绿素含量和和净光合速率。结果表明,在土壤干旱胁迫下不同白品系在不同生育时期的单叶面积、单株叶面积、出叶速度及净光合速率都下降,在一定土壤水分范围内,叶绿素含量随土壤水分的下降而增加,抗旱性强的品系受土壤干旱胁迫的影响较小。     

Effects of two novel Wx-A1 alleles of common wheat (Triticum aestivum L.) on amylose and starch properties

Common wheat (Triticum aestivum L.) has three Wx proteins (Wx-A1, Wx-B1, and Wx-D1), which are granule-bound starch synthases I and are responsible for the amylose synthesis of flour starch. The effects of two novel Wx-A1 proteins identified by gel electrophoresis on amylose content and starch properties were analyzed. The variant Wx-A1 protein coded by the Wx-A1i allele was present in smaller amounts and produced less amylose (7.3%) compared to standard lines with the Wx-A1a allele (21.5%). Wx-A1i generated altered starch properties; greater swelling power (SP), glucoamylase digestibility, starch paste clarity, and gelatinization enthalpy in differential scanning calorimetry. The starch from Wx-A1i also showed an altered pasting profile on a Rapid Visco-Analyzer, greater peak viscosity, smaller final viscosity, and lower pasting temperature. The Wx-A1i allele is a novel genetic resource for reducing amylose content in wheat. The other Wx-A1 protein coded by the Wx-A1j allele showed a more basic isoelectric point compared to Wx-A1a on an electrophoretic gel. The amylose content of Wx-A1j did not differ from standard Wx-A1a. Starch SP, paste clarity, and glucoamylase digestibility also suggested that Wx-A1j produced amylose as much as Wx-A1a.     

Effects of soil compaction in the sub-humid cropping environment in Pakistan on uptake of NPK and grain yield in wheat (Triticum aestivum): II: Alleviation

Alleviation of soil compaction can be achieved through application of appropriate measures which will vary from soil to soil and with the socio-economic factors of the farmers. The effects of alleviation measures applied to artificially compacted soil on yield components, grain yield, dry matter and nutrient uptake by wheat was studied at the Agriculture Research Institute, Mingora, Pakistan, in two separate experiments in 2002–2003 and 2003–2004. The improvement measures included deep ploughing (DP), farmyard manure (FYM) and gypsum (GYP), and comprised a compacted control and four treatments T1 (control), T2 (DP), T3 (DP + FYM), T4 (DP + gypsum) and T5 (DP + FYM + GYP), arranged in completely randomized block design replicated four times. Improvement measures applied to compacted soil significantly decreased soil bulk density and increased total porosity. Bulk density decreased in the range of 12–15% while total porosity showed an increase of 16–23% over the control. Improvement measures significantly increased concentration and uptake of NPK in both years. Higher concentration and uptake was recorded during the second year as compared to the first year, probably as a result of higher seasonal rainfall in the second year. The uptake of NPK by wheat plants increased in the range of 43–51, 25–94 and 11–28%, respectively, over plants in the compacted control. Similarly, improvement treatments increased grains spike⁻¹, thousand grain weight, dry matter accumulation and grain yield in the range of 14–21, 5–14, 3–10 and 21–37% respectively, over the control. This work demonstrates that it is possible to overcome the deleterious effects of compaction induced by wheeled traffic, and improve crop yields and nutrient uptake in intensive cropping systems in rainfed environments in Pakistan and similar environments.     

Influence of treatment of soil with carbofuran on the subsequent performance of insecticides against cabbage root fly (Delia radicum) and carrot fly (Psila rosae)

A sandy loam soil was treated with 2·5 kg carbofuran/ha on each of five occasions between May and October 1984. In 1985, the field performance of benfuracarb, carbofuran, carbosulfan, chlorfenvinphos and furathiocarb against cabbage root fly (Delia radicum) and carrot fly (Psila rosae) was studied in this soil and in identical but previously untreated soil by applying exponentially increasing doses of granular formulations to radish and carrots at drilling. Chlorfenvinphos reduced numbers of larvae of both pests by >90% in both soils but the performance of all the carbamates was significantly worse in the previously treated soil than in the previously untreated soil. Dazomet, a partial soil sterilant, was applied to part of the experimental area in October 1985 and the performance of aldicarb, carbofuran, carbosulfan, chlorfenvinphos and thiofanox against cabbage root fly was assessed in 1986. The efficiency of aldicarb and chlorfenvinphos was not affected by any of the pre-treatments but that of carbofuran and carbosulfan was reduced in all the pre-treated soils, including the soil treated with dazomet. Carbofuran residues in radish were detectable only in plants grown in previously untreated soil. In laboratory incubations, a dustless base formulation of carbofuran was degraded more quickly in pre-treated than in untreated soils but a granular formulation was degraded more slowly and at a similar rate in both soils.     

玉米和小麦对黏虫生长发育和繁殖的影响

在室内温度15℃～25℃(平均18℃)、相对湿度70％、光周期12 L:12 D条件下,测定黏虫在玉米和小麦上各发育阶段的历期、存活率和产卵量,组建黏虫在两种寄主植物上的生命表.结果表明,与幼虫期取食小麦相比,取食玉米的幼虫发育历期极显著缩短(1.168±0.337)d;成虫产卵前期和产卵历期分别显著缩短和延长(1.0...     

橡胶叶水浸提液对花生幼苗早期根系形态及其生理特性的影响

为深入理解橡胶树的化感抑制作用,采用适当浓度的橡胶叶水浸提液处理刚萌动的花生种子10 d,测定花生幼苗早期根系形态及其生理指标。结果表明:橡胶叶水浸提液能显著降低花生幼苗胚根长度、苗高、根鲜重、地上部鲜重以及根冠比,对根生长的抑制作用比地上部强烈;能显著降低根系总长、根表面积、根体积和根尖数,但对根平均直径有轻微的促进作用,与对照相比,差异不显著;能显著降低根系SOD、POD、CAT活性、可溶性蛋白质、可溶性糖、脯氨酸含量以及根系活力,却明显增加根系MDA含量和相对电导率。说明橡胶叶水浸提液可通过破坏花生幼苗的抗氧化防御机制,降低其渗透调节能力,减少根系的吸收面积,抑制根系的吸收活性来抑制花生幼苗的生长。     

Effects of relative humidity and high temperature on spore germination and development of tomato powdery mildew (Leveillula taurica)

The effects of relative humidity (RH) and temperature on tomato powdery mildew (Leveillula taurica) were studied in controlled environments to define conditions that affect disease development in fresh market tomatoes in California. Gradients of RH (20–90%) at constant temperatures (20–30°C) were generated in single growth chambers to determine their effect on mildew development on mature tomato plants. Temperatures of 30°C and above were deleterious for spore germination, germ tube elongation, and disease development. Lesion growth and rate of disease progress were significantly higher at 20°C than at 25°C. Low RH levels (20–40%) reduced spore germination and lesion growth, accelerated host tissue death and reduced disease progress. Intermediate RH levels (50–70%) increased spore germination and optimized disease development, provided temperatures were maintained within favorable limits. High RH levels (80–90%) were favorable for spore germination but continued exposure to these conditions led to a limited lesion growth and disease progress. Short daily periods (two or three daily exposures of at least 2 h) of high temperatures (35°C) suppressed disease development by 70–92%.