韭菜迟眼蕈蚊紫外敏感视蛋白基因的克隆及光强度对其表达量影响

为明确韭菜迟眼蕈蚊Bradysia odoriphaga紫外敏感视蛋白基因Bo-uv的作用及其与趋光性的关系,利用常规PCR方法克隆获得Bo-uv基因的全长cDNA序列,分析了其敏感视蛋白的氨基酸序列与其它12种昆虫同源蛋白氨基酸序列之间的系统进化关系,运用qPCR技术检测了不同发育阶段、不同组织及不同光强度下Bo-uv基因的相对表达量。结果表明,Bo-uv基因cDNA全长2 757 bp,开放阅读框1 542 bp,编码514个氨基酸。韭菜迟眼蕈蚊紫外敏感视蛋白的氨基酸序列与其它12种昆虫同源蛋白的氨基酸序列一致性为21.93%～43.00%,与橘小实蝇Bactrocera dorsalis的氨基酸序列同源性最高。Bo-uv基因在韭菜迟眼蕈蚊蛹末期、成虫期表达,在成虫头部的相对表达量较高。在0～10 000 lx光强范围内雌、雄成虫体内该基因的相对表达量均呈先增高后降低趋势。与对照相比,1 000 lx光强度下其相对表达量显著升高,10 000 lx时相对表达量显著降低。表明光强度能够有效地调控Bo-uv基因的表达,该基因在韭菜迟眼蕈蚊感知外界光刺激过程中具有重要作用。     

Effects of selective cutting and timing of herbicide application on growth and development of Cirsium arvense in spring barley

Recently, a new implement for controlling weeds in cereals (CombCut) has been developed. It cuts weeds in growing cereals without damaging them by using the physical differences (in height, stem thickness, straw stiffness and branching pattern) between crops and weeds. To evaluate and compare the effects of selective cutting with different timings of herbicide application on Cirsium arvense in spring barley, a randomised block experiment was conducted in Sweden in 2015–2017, in a field with a naturally occurring C. arvense population. Treatments consisted of control (C), herbicide application at 4–5‐leaf stage of C. arvense (H1), herbicide application at 8–10‐leaf stage (H2) and selective cutting at 10‐leaf stage (S). The treatments were performed in 2015 and repeated in 2016 in the same plots, and a final evaluation was performed in 2017. Compared to the control, S, H1 and H2 were equally efficient in reducing above‐ground biomass production of C. arvense and increasing spring barley grain yield per unit area. The number of C. arvense shoots per area was, however, higher in S compared to H1 and H2. No differences in control effects on shoot number were observed between H1 and H2. Our study indicates that (i) selective cutting (S) reduces C. arvense equally efficient as herbicide application and (ii) early herbicide spraying is as efficient as spraying later in the season.     

The importance of reduced light intensity on the growth and development of six weed species

Crops limit light for photosynthesis and growth of weeds. We studied the effect of reduced light on performance of six weed species [one invasive species (Amsinckia micrantha), three common species (Veronica persica, Capsella bursa‐pastoris, Viola arvensis) and two less common weeds (Anagallis arvensis and Scleranthus annuus)]. In two glasshouse experiments, six light levels were achieved aiming at 0%, 20%, 50%, 80%, 90% and 95% reduction of light and corresponding with daily light integrals (DLI) of 12.4, 9.63, 7.13, 2.74, 0.95 and 0.69 mol m^?2 day^?1 in experiment 1 and 21.2, 18.0, 10.7, 3.71, 1.64 and 1.20 mol m^?2 day^?1 in experiment 2. The number of leaves was strictly controlled by DLI. Chlorophyll content index, maximum photochemical efficiency of photosystem II (F_v/F_m), stomatal conductance, flowering and dry matter were strongly reduced when DLI was reduced to 0.69–3.71 mol m^?2 day^?1 for all species. Threshold DLI for flowering was ca. 3.71 mol m^?2 day^?1 for S. annuus, V. arvensis, A. arvensis and V. persica, while C. bursa‐pastoris deviated by flowering at DLI of 0.95 mol m^?2 day^?1. This may explain why C. bursa‐pastoris is common in the seedbank of Danish arable soils in spite of intensive farming with well‐fertilised and dense crops.     

331份四川小麦品种(系)在甘肃陇南抗条锈性表现及利用价值

2014年-2017年度先后对331份四川省小麦生产品种(系)在温室进行苗期人工接种条锈菌混合菌鉴定和甘谷试验站大田成株期分别接种CYR32、CYR33、CYR34、G22-14、中4-1和混合菌鉴定,同时在甘谷试验站和汪川良种场两地进行自然诱发鉴定。结果发现:在人工接种条件下,苗期、成株期表现抗病的分别有‘XK201465’等36份和‘XK20132’等72份材料,分别占10.88%和21.75%;有‘XK62483’等11份材料全生育期表现抗病,占3.32%;两地三年自然诱发鉴定发现,仅有‘XK20132’等5份材料在两地均表现抗病,有‘川农17’等30份材料具有慢条锈性。对供鉴材料在甘肃陇南的利用前景进行了分析。     

基于EPG技术分析杭菊两主栽品种对三种菊蚜抗性及其相关抗性物质

为比较杭白菊主栽品种早、晚小洋菊对菊小长管蚜Macrosiphoniella sanborni、棉蚜Aphis gossypii、桃蚜Myzus persicae的抗性,通过刺吸电位技术(electrical penetration graph,EPG)研究菊蚜在菊顶叶上刺吸行为,并检测了菊顶叶主要化合物。结果表明:在晚小洋菊上,菊小长管蚜的E1、E2波平均持续时间4.31、3.47 min,分别短于在早小洋菊上的4.63、3.75 min;棉蚜、桃蚜的E1、E2波平均持续时间分别为4.32、4.72 min和4.92、4.64 min;3种蚜虫的平均刺探次数均大于在早小洋菊上的平均刺探次数。聚类分析结果显示,2个主栽品种之间抗性存在差异。早小洋菊顶叶平均可溶性糖和可溶性蛋白含量分别为2.71 mg/g和25.36 mg/g,均高于晚小洋菊;早小洋菊顶叶总酚含量为0.24 mg/g,显著低于晚小洋菊;早、晚小洋菊总黄酮含量分别为3.46 mg/g和3.37 mg/g。早小洋菊顶叶可溶性糖、可溶性蛋白含量基本上与每种菊蚜的E1、E2波持续时间显著正相关,总酚含量、总黄酮含量与每种菊蚜的E1或E2波持续时间显著负相关。推测早小洋菊对于菊长管蚜的抗性稍弱于晚小洋菊,2种杭白菊对棉蚜或桃蚜的抗性相当,且菊叶中的这4种物质含量与抗蚜性相关。     

BHT对苹果采后灰霉病的防效及防御酶活性和丙二醛含量的影响

为探究2,6-二叔丁基-4-甲基苯酚(2,6-di-tert-butyl-4-methylphenol,BHT)对苹果采后灰霉病的防效和防病机制,采用平板法和刺伤接种法测定了BHT对灰霉病菌Botrytis cinerea的抑制作用及果实内防御酶活性和丙二醛含量的影响。结果表明,0.1 mmol/L BHT对苹果灰霉病的防效最佳,处理苹果后间隔48～96 h接种灰霉病菌,其防效可达68.59%～73.55%,其次为0.2、1.0 mmol/L BHT处理,但防效均低于52.94%。0.1 mmol/L BHT处理对灰霉病菌菌丝生长和分生孢子萌发无显著抑制作用,但可显著增强果实内超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性以及总抗氧化能力,其峰值是对照的1.82～5.28倍,且均显著高于单独接种灰霉病菌的处理。此外,单独接种灰霉病菌的苹果果实内丙二醛含量快速升高,最大增幅达251.49%,而BHT处理后丙二醛含量变幅较小,最大增幅仅为83.95%。表明BHT可通过增强苹果果实内防御酶活性水平和总抗氧化能力来降低丙二醛的积累,从而提高果实对灰霉病的抗性。     

氯虫苯甲酰胺和氟虫腈对黏虫细胞色素P450基因表达的影响

为筛选出黏虫Mythimna separata参与杀虫剂解毒代谢的主效细胞色素P450基因,采用叶片浸渍法测定了用于处理黏虫3龄幼虫的亚致死浓度,通过构建转录组测序文库并结合数字基因表达(digital gene expression,DGE)对不同处理的黏虫进行测序,并运用实时荧光定量PCR(realtime quantitative polymerase chain reaction,RT-qPCR)技术验证12个P450基因的表达情况。结果表明,用于处理黏虫的氯虫苯甲酰胺和氟虫腈亚致死浓度LC_(10)分别为0.15、13.66 mg/L;对照样品、氟虫腈处理样品和氯虫苯甲酰胺处理样品分别获得59 521 504、64 838 148和41 722 990个原始序列数据,分别获得57 441 216、62 368 912和40 285 164个过滤后的序列数据;过滤后的序列长度分别为8.62、9.36和6.04 G;碱基错误率均为0.02%;Phred数值大于20、30的碱基占总碱基的百分比均高于90.59%;鸟嘌呤+胞嘧啶(guanine cytosine,GC)含量分别为47.16%、48.94%和47.55%,表明转录组测序质量较高;黏虫受氯虫苯甲酰胺胁迫后,29个P450基因表达量上调,27个P450基因表达量下调;黏虫受氟虫腈胁迫后,23个P450基因表达量上调,26个P450基因表达量下调;12个P450基因表达量的RT-qPCR技术检测结果与DGE测序文库显示的结果基本一致。     

棉铃虫脂肪酸结合蛋白的克隆与表达

为深入了解棉铃虫Helicoverpa armigera脂肪酸结合蛋白HaFABP1在参与细胞内脂肪酸代谢过程中的功能,基于酵母单杂交结果从幼虫中肠cDNA中扩增得到HaFABP1的开发阅读框,构建重组菌株BL21-pET28a-HaFABP1,进行融合蛋白His-HaFABP1的诱导和纯化,并利用实时荧光定量PCR检测棉铃虫不同时期和组织中HaFABP1的表达规律,最后检测2-十三烷酮处理下棉铃虫6龄幼虫中肠组织内HaFABP1的变化情况。结果显示,克隆获得的棉铃虫HaFABP1为405 bp,编码134个氨基酸,相对分子量和等电点分别为15.08 kD和5.54;在37℃下用0.5 mmol/L异丙基硫代半乳糖苷(IPTG)诱导重组菌株4 h后,得到约18.4 kD的可溶性蛋白His-HaFABP1,纯化后的融合蛋白条带单一且大小符合预期;HaFABP1在棉铃虫的脂肪体、中肠、体壁和头部中都有表达,在头部的表达量最低,在中肠中的表达量最高;HaFABP1在棉铃虫幼虫的每个发育时期都有表达,表达量总体呈现先降低后升高的趋势,4龄时最低而1龄时最高;10 mg/g 2-十三烷酮处理饲料饲喂棉铃虫6龄幼虫6 h和15 h后,中肠内HaFABP1的表达量与对照相比显著提高,且随着时间的延长逐渐增加。表明HaFABP1与棉铃虫的生长发育有关,并且有可能参与了昆虫的解毒过程。     

Maize defence mechanisms against the European corn borer,Ostrinia nubilalis Hübner (Lepidoptera: Crambidae)

Maize is arguably the most widely grown crop in the world, but it is often associated with one of its major insect pests, the European corn borer (ECB). The damage caused by this species to maize production is generally variable, but in many cases it is economically significant. This review paper provides an overview of the research findings on the natural plant defence mechanisms against ECB larvae published till now. What is resistance and how it is achieved, what is the chemical response of maize plants to insect feeding and how tolerance can be increased. A short introduction in breeding for resistance and a discussion if the mentioned traits can be used in conventional breeding in order to create maize hybrids less affected by ECB are given.     

不同生境黑果枸杞实生苗生长及土壤养分空间差异的研究

研究不同生境黑果枸杞实生苗数量、生长状况、生物量分配及土壤养分空间差异,探讨环境因子对黑果枸杞实生苗生长的影响,为黑果枸杞种群恢复及持续经营提供理论依据。采用固定样地调查法,于2016年对张掖市甘州区、临泽县、肃南县及周边地区的农田地埂、水渠边、盐化沙地、盐碱荒地等各生境黑果枸杞进行调查。研究结果表明：不同生境均有黑果枸杞实生苗分布,农田地埂生境实生苗数量相对水渠边、盐化沙地、盐碱荒地分别增加66.67%、122.22%、215.79%。因环境条件差异,不同生境的黑果枸杞实生苗采取了不同的生存策略适应环境：农田地埂生境的黑果枸杞主要为增高生长,盐化沙地的黑果枸杞主要为冠幅的增长,而盐碱荒地的黑果枸杞主要为增粗生长。农田地埂生境0~20 cm土层有机质含量相对水渠边、盐化沙地、盐碱荒地分别增加28.50%、2.62%、10.13%;全氮含量分别增加44.08%、33.16%、72.41%;有效氮含量分别增加46.81%、0%、50%。空气湿度、土壤含水量对黑果枸杞幼苗数量及幼苗生长有显著影响。在今后的黑果枸杞栽培管理中,幼苗期应加强水分管理。