抗性野燕麦生物型对高效氟吡甲禾灵具有一定的生理适应性

<正>为探明春油菜田野燕麦(Avena fatua L.)对高效氟吡甲禾灵的抗性生理机制,青海大学农林科学院研究人员在实验室对抗性生物型野燕麦和敏感性生物型喷施高效氟吡甲禾灵后测定了相关生理指标的变化。结果表明,喷施高效氟吡甲禾灵后,野燕麦敏感种群(S)的叶绿素含量呈逐渐降低的趋势,抗性种群(R)的叶绿素含量变化趋势不明显;野燕麦抗性种群(R)喷药处理后丙二醛含量始终很     

油菜田看麦娘对精喹禾灵抗性监测及与烯草酮交互抗性

通过对看麦娘抗药性水平的检测以及抗性机理的研究,以期为油菜田看麦娘的抗性治理和科学合理用药提供理论依据。采用整株法测定了长江中下游地区的4个省13个市17个地区的油菜田看麦娘生物型对精喹禾灵的抗性水平及与烯草酮的交互抗性,分别测定了精喹禾灵与烯草酮对抗性看麦娘(R-TY)、敏感看麦娘(S-NJ)体内GSTS活性。抗精喹禾灵监测结果显示:TY生物型相对抗性倍数最高,为28.92,GR50为90.183。其次为YZ生物型和BLD生物型,GR50分别为34.480和45.472,相对抗性倍数分别为11.06和14.58。其余生物型相对抗性倍数在1.62~9.16之间。与烯草酮的交互抗性结果显示:对精喹禾灵产生抗性的TY、BLD生物型对烯草酮也产生了抗性,存在交互抗性,而对精喹禾灵敏感的DYX生物型看麦娘却对烯草酮产生了抗性,说明看麦娘生物型中存在不同的抗性模式。GSTS活性测定结果显示:经药剂处理后,R-TY生物型GSTS活性始终比敏感生物型S-NJ高,表明TY生物型产生抗性的原因可能是GSTS对药剂的代谢作用增强。     

稀禾啶、烯草酮等6种除草剂对不同叶龄期野黍的防治效果比较

为筛选出有效防治大豆田野黍的茎叶处理除草剂并探索适宜施药时期,采用盆栽试验研究了稀禾啶、烯草酮、高效氟吡甲禾灵、精吡氟禾草灵、精喹禾灵、喹禾糠酯对不同叶龄期野黍的防治效果.结果表明,防治一叶期至二叶一心期野黍可施用12.5％稀禾啶机油乳油131.25ga.i./hm2、240g/L烯草酮乳油90.00g a.i./hm2、10.8％高效氟吡甲禾灵乳油64.80g a.i./hm2、15％精吡氟禾草灵乳油135.00g a.i./hm2、5％精喹禾灵乳油71.25g a.i./hm2、40g/L喹禾糠酯乳油36.00g a.i./hm2,防治三叶期至三叶一心期野黍可施用12.5％稀禾啶机油乳油168.75g a.i./hm2、10.8％高效氟吡甲禾灵乳油97.20g a.i./hm2,仅12.5％稀禾啶机油乳油能有效防治四叶期以上野黍,施药量至少187.50g a.i./hm2.上述处理在施药后30d对野黍的株防效都超过90％.防治野黍的最佳时期为三叶期前,越晚施药,可供选择的除草剂种类越少,且需提高施药量.     

棉花花生间作田中花生蚜对吡虫啉代谢抗性机制初步研究

【目的】探讨棉花花生间作田中棉蚜(Aphis gossypii Glover)和花生蚜(Aphis craccivora Koch.)对吡虫啉抗性的差异以及花生蚜对吡虫啉代谢抗性的机制,以科学有效防治这一类害虫,避免其对吡虫啉的抗性快速发展。【方法】采集山东巨野和临清2个地区的棉花花生间作农田中的棉蚜和花生蚜,对这两个地区的地理种群和室内敏感品系进行了吡虫啉的室内毒力测定;使用增效剂顺丁烯二酸二乙酯(Diethyl maleate, DEM)、胡椒基丁醚(Piperomyl butoxide, PBO)和磷酸三苯酯(Triphenyl phosphate, TPP)3种增效剂进行了增效剂效果试验;并检测了2个地理种群和室内敏感品系花生蚜细胞色素P450单加氧酶(Cytochrome P450 monooxygenase,P450)、谷胱甘肽S-转移酶(Glutathione S-transferase, GST)和羧酸酯酶(Carboxylesterase, CarE)3种解毒代谢酶的活性。【结果】临清和巨野2个地区的棉蚜对吡虫啉抗性处于中等水平,抗性倍数分别为43.2倍和54.6倍;而花生蚜对吡虫啉则处于敏感或低水平抗性,2个种群抗性倍数分别为3.7倍和8.3倍。防治花生蚜的增效剂试验结果表明,巨野种群中,PBO、DEM对吡虫啉具有显著的增效作用,增效比分别达到3.63、1.95,而TPP不具有增效作用;在临清种群中,PBO对吡虫啉具有显著的增效作用,增效比达到3.05,而DEM和TPP不具有增效作用。对花生蚜的代谢酶活力测定发现,巨野种群与敏感品系相比,CarE活性没有显著差异,而P450和GST活性显著高于敏感品系;临清种群与敏感品系相比,CarE和GST活性无显著性差异,而P450活性显著高于敏感品系。【结论】间作农田中2种蚜虫对吡虫啉的敏感性差异较大,需要合理施药延缓抗药性的增强,同时推断P450和GST在花生蚜对吡虫啉的抗药性中发挥一定的作用。     

乳果糖对黄瓜枯萎病防效及其诱导抗性的作用

测试乳果糖对黄瓜枯萎病的防治作用,并通过黄瓜相关抗性酶活性的影响,明确乳果糖对黄瓜枯萎病的防治效果及初步作用机制。采用生长速率法测定乳果糖对黄瓜枯萎病菌的抑制率;采用胚根接种法、灌根接种法进行盆栽防效测试;相关抗性酶活性测试采用分光光度法。1 mg/L乳果糖的盆栽防效最好,胚根期浸种和子叶期喷雾处理的防治效果分别为43.87%和41.97%,其次是0.1 mg/L乳果糖的盆栽防效,分别为39.62%和37.21%,而离体抑菌活性测试结果显示乳果糖对黄瓜枯萎病菌无杀菌活性。对黄瓜防御反应酶系过氧化物酶(POD)、过氧化氢酶(CAT)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性进行测试,结果表明乳果糖处理后黄瓜内各防御酶系均比对照高,尤其1 mg/L乳果糖胚根浸种和子叶期喷雾处理黄瓜PAL比对照分别提高了97.5%和92.4%。综上,乳果糖对黄瓜的诱导抗性作用是防治黄瓜枯萎病的主要机制,并可作为新型药剂用于农业植物病害防治中,具有较大开发潜力。     

抗虫棉品系L22依赖抗坏血酸H2O2清除酶系统活性的降低

以早衰型转 Bt基因抗虫棉 L2 2为主要试材 ,研究了其体内活性氧代谢和一些抗氧化酶活性与对照常规棉 JM1 1、抗虫棉 33B的差异。结果表明 ,抗虫棉 L 2 2在生长中期时叶片中 H2 O2 含量和膜脂过氧化产物丙二醛 ( MDA)显著增高 ,在依赖抗坏血酸 ( As A)的 H2 O2 清除酶系统中 ,抗坏血酸过氧化物酶 ( As A- POD)、脱氢抗坏血酸还原酶 ( DR)、谷胱甘肽还原酶 ( GR)等酶活性极显著低于常规棉 JM1 1和 33B,叶片中 As A含量也以 L2 2为最低 ,而 DAs A/As A是最高的 ,分别是JM1 1和 33B的 3.75倍和 4.31倍。初步认为 L2 2出现早衰现象与其体内活性氧代谢失调和依赖As A的 H2 O2 清除酶系统活性显著降低有关 ,并分析了可能的原因     

硅对干旱胁迫下燕麦根系响应的分子机理

硅对非生物胁迫下植物生长发育的帮助已有许多报道,但硅在干旱胁迫下影响燕麦根系的分子机制尚不清楚。本试验采用加拿大引进燕麦品种‘甜燕Ⅰ号’,以Na_2SiO_3·9H_2O作为硅源,以聚乙二醇(PEG-6000)模拟干旱胁迫环境,研究了对照处理、干旱胁迫处理(25%PEG-6000)和硅+干旱胁迫处理(10 mmol/L Na_2SiO_3·9H_2O+25%PEG-6000)条件下对燕麦根系的影响,通过转录组分析(176 555个基因),旨在比较3种处理条件下燕麦根系的差异表达基因。比较转录组学分析表明,在干旱胁迫下,硅在改变234个基因的表达水平中起着重要作用。GO富集分析表明,氧化还原酶活性、细胞氮化合物代谢过程、细胞大分子代谢过程等相关基因的富集程度显著提高,并且这些基因与非生物抗性有着密切的联系,表明硅可能诱导燕麦幼苗的耐旱性。通过研究硅介导的抗旱机制,为干旱地区农作物生产中硅的应用提供理论依据。     

表油菜素内酯对重度镉胁迫下辣椒幼苗生理特性及抗逆基因的影响

为探究表油菜素内酯(EBR)对辣椒镉抗性的作用机制,以晋椒503为试验材料,在苗期进行高浓度镉(100μmol/L)胁迫,对喷施不同浓度EBR的辣椒幼苗各项生理性指标和抗逆相关基因进行了比较。结果表明,高浓度的镉离子可下调辣椒幼苗的生物量、光合色素含量、抗氧化物酶活性、抗坏血酸(AsA)-谷胱甘肽(GSH)循环的清除效率,上调辣椒DHAR、GR、MDHAR、CAT和WRKY25基因表达量;施加100μmol/L的EBR可以激活DHAR、MDHAR和WRKY25等基因的表达,增加辣椒幼苗的生物量,增加叶片中光合色素含量,提高过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、单脱氢抗坏血酸还原酶(MDHAR)、脱氢抗坏血酸还原酶(DHAR)和谷胱甘肽还原酶(GR)活性,提高AsA-GSH循环系统还原态与氧化态的比例,进而降低了O_2~(-·)产生速率和H_2O_2含量;高浓度的镉离子虽然可以激活GR、CAT和DHAR基因表达,但却抑制了相应酶的活性,阻碍了辣椒对重金属正常的响应路径,从而造成了严重的生理胁迫。适宜浓度的EBR可通过对转录因子和酶活性的调控有效缓解镉胁迫对辣椒幼苗的毒害,提升辣椒的耐镉能力。     

拟南芥硫氧还蛋白M1型基因(AtTRX m1)与环境逆境之间的关系

硫氧还蛋白家族是约12 kD的小分子蛋白质,含有高度保守的活性反应位点WCG/PPC,催化硫醇一二硫键相互交换,调节细胞内的氧化还原作用.在本研究中,通过RT-PCR法获得目的基因拟南芥硫氧还蛋白M1型基因(AtTRX m1,GenBank Accession No.At1g03680).通过Northern杂交分析拟南芥悬浮细胞系在100 mmol/L NaCl、10 mmol/L NaHCO3、50 μmol/L ABA、10 mmol/L H2O2等逆境处理下mRNA表达水平的变化和硫氧还蛋白M1型转基因植株对NaCl、NaHCO3盐及ABA逆境的抗性分析,表明硫氧还蛋白M1型基因与生物环境胁迫有一定的相关性,尤其是氧化胁迫,能够增强植物对逆境的耐受力.从而为进一步研究硫氧还蛋白基因家族与逆境之间的相关作用奠定了基础.     

不同药剂对打破玫瑰香葡萄芽休眠的效果研究

以日光温室内葡萄品种‘玫瑰香’（Vitis vinifera ‘Muscat Hamburg’）为试材,选择不同化学药剂对其进行破眠试验,探讨单氰胺等外源生长调节剂打破休眠的效应以及休眠过程中抗性物质含量的变化。结果表明：2.5% 单氰胺打破葡萄的休眠效果最好,可使萌芽期提前15天左右,萌芽整齐度及萌芽速率高,显著提高了SOD、POD酶的活性,对CAT酶活性有一定的抑制作用,对丙二醛含量的影响不显著;200 mg/LGA3对打破休眠基本无效甚至有抑制作用,处理后萌芽率低于对照,但可促进芽体形成新梢;150 mg/L 6-BA对打破休眠亦有一定的效果,但对终萌芽率影响甚微。     

Development of rice (Oryza sativa) lines resistant to aryloxyphenoxypropionate herbicides through induced mutation with gamma rays

The aryloxyphenoxypropionate herbicides (APPs) are graminicides with excellent control of many grass weeds species, including weedy rice (Oryza sativa L.). These herbicides block the fatty acid biosynthesis by inhibiting the enzyme acetyl‐CoA carboxylase (ACCase), resulting in the death of susceptible plants. Inducing mutation with gamma rays to rice seeds, two lines resistant to APPs herbicides were developed. Plant dose–response assays confirmed the resistance to the APPS herbicides quizalofop‐p‐ethyl and haloxyfop‐p‐methyl. The carboxyltransferase domain fragments of ACCase from the resistant biotype and susceptible control were sequenced and compared. A point mutation was detected in the amino acid position 2,027 (Rice Genome Annotation Project: Os05g22940.1). Results indicated that resistance to APPs is a consequence of an altered ACCase enzyme that confers resistance. The use of APPs herbicide‐resistant rice lines represents an innovative and promising alternative for weedy rice control in paddy rice systems.     

野生二粒小麦与野燕麦杂种核型研究

1989年用野生二粒小麦(Triticum dicoccoides Corn.2n=4x=28)与通北野燕麦(Avenafatua L.2n=6x=42)杂交成功,F_2分离出燕麦型、二粒小麦型、硬粒小麦型、斯卑尔脱型和普通小麦型。斯卑尔脱型F_4中的一个类型,与双亲野生二粒小麦和通北野燕麦的核型进行比较研究。杂种中有一对近端着丝点染色体,5对随体染色体。近端着丝点染色体来源于通北野燕麦,5对随体染体来源于双亲野生二粒小麦和通北野燕麦。证明野生二粒小麦与通北野燕麦杂种斯卑尔脱型是真杂种。     

鬼臼毒素和脱氧鬼臼毒素抑菌和除草活性初探

对从砂地柏中分离得到的四个化合物鬼臼毒素、脱氧鬼臼毒素、4-表松香醛和7,13-松香二烯-3-酮的杀虫、抑菌及除草活性进行了初步测试。结果表明,4-表松香醛和7,13-松香二烯-3-酮对粘虫、小菜蛾及菜青虫等具有较强的拒食活性及一定的毒杀作用;鬼臼毒素和脱氧鬼臼毒素对辣椒疫霉、番茄灰霉及油菜菌核具有较好的抑制活性;除草活性研究表明鬼臼毒素对反枝苋、野燕麦根的抑制效果较强,脱氧鬼臼毒素对反枝苋、野燕麦及婆婆纳根的抑制效果较强,其抑制率均达到80％以上。     

Inheritance of resistance to Striga gesnerioides biotypes from Mali and Niger in cowpea (Vigna unguiculata (L.) Walp.)

Pot and laboratory experiments were performed in order to elucidate the genetics of resistance of three cowpea (Vigna unguiculata (L.) Walp.) resistant sources to two biotypes of the parasitic weed Striga gesnerioides (Willd.) Vatke (witchweed). B301, Suvita-2 and IT82D-849 were crossed to susceptible cultivars. Roots of each plant of parental, F₁, F₂, BC₁ and BC₂ populations were washed free of soil and examined closely for S. gesnerioides attachment. Data on resistant and susceptible cowpea plants were analyzed using the chi-square test to ascertain the goodness of fit to different genetic ratios. Segregation patterns indicate monogenic dominant inheritance of resistance to both S. gesnerioides biotypes in B301. Suvita-2, which is susceptible to the biotype from Maradi, Niger, showed segregation patterns that indicate monogenic dominant inheritance of resistance to S. gesnerioides biotype from Cinzana, Mali. Results also indicate monogenic dominant inheritance of resistance to S. gesnerioides biotype from Cinzana in IT82D-849. However, the inheritance of resistance to the biotype from Maradi would be monogenic and recessive in this line. These results suggest that the resistance of all three sources would be easy to transfer to promising breeding lines. This revised version was published online in July 2006 with corrections to the Cover Date.     

AFLP genetic diversity analysis in Russian wheat aphid resistant wheat accessions

Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is an important insect pest which causes severe economic losses in wheat (Triticum spp.). Among the various U.S. RWA biotypes, biotype 1 (RWA1) and biotype 2 (RWA2) are the most prevalent and most virulent on cultivated genotypes. Although many sources of resistance to these biotypes are available among landraces, their relatedness should be characterized to permit their more efficient use in breeding programs. In this study, 38 hexaploid accessions resistant to biotype 1 and/or biotype 2 were evaluated for genetic diversity based on amplified fragment length polymorphisms (AFLP). Fifteen AFLP selective primer combinations were used to genotype these accessions, resulting in 893 amplicons. Of these, 274 (30.6%) informative polymorphic bands were used for genetic diversity analysis. Genetic similarity coefficients ranged from 0.47 to 0.87 among the resistant accessions, indicating high genetic diversity among them. Cluster analysis grouped the 38 accessions into two major clusters, I and II, including resistant lines for RWA1 and RWA2. The study indicated that accessions in the National Small Grains Collection conferring RWA1 or RWA2 resistance comprise a diversified population which should support introgression efforts and provide genetic diversity for future breeding for RWA resistance.     

普通野生稻(Oryza rufipogon Griff.)抗稻褐飞虱新基因的鉴定与利用

稻褐飞虱(BPH,NilaparvatalugensSt#l)是中国和世界稻区最严重的水稻害虫之一,发现和利用新抗性基因和进行抗性种质创新对于稻褐飞虱抗性品种的培育具有重要的意义。本研究进行了1200多份普通野生稻(OryzarufipogonGriff)种质对多种BPH生物型的抗性鉴定,获得了30份抗性资源,其中6份对分布于世界主要稻区的稻褐飞虱生物型1和2、孟加拉、湄公河(越南)、九龙江(越南)、潘特纳加(印度)等6种生物型或其中5种具有广谱高抗性。遗传分析证明了这些种质对BPH生物型2和九龙江生物型的抗性受2对重复作用隐性基因控制,对潘特纳加生物型的抗性受1对隐性基因控制,表明抗源对不同褐飞虱生物型具有不同的遗传机制。普通野生稻材料2183存在的2对隐性基因很可能是新发现的基因,因为在这些染色体区域还没报道有BPH抗性基因,这两对基因暂命名为bph18(t)和bph19(t)。研究总共培育出143份抗性创新种质和6份抗性品系或高产优质杂交水稻组合,这些优良的抗性创新种质为培育抗性新品种建立了坚实的基础。     

抗苯磺隆猪殃殃分子机制研究

近几年,河南省各地抗苯磺隆猪殃殃(Galium aparine)发生严重,常规剂量苯磺隆已无法防治。为了明确猪殃殃产生苯磺隆抗性的分子机制,通过提取总DNA、ALS基因扩增和基因测序的方法比对抗性及敏感种群的ALS保守区序列,明确抗性种群ALS基因突变位点。相比于敏感猪殃殃,抗性种群的高度保守区(Domain A)197 位脯氨酸(Pro)突变为苏氨酸(Thr)和亮氨酸(Leu),非保守区457 苏氨酸(Thr)突变为丝氨酸(Ser)3 种突变形式。其中,猪殃殃对苯磺隆产生抗药性的原因可能是其197 位氨基酸发生突变。     

恩诺沙星对两种鲟细胞色素P450活性影响的比较研究

将恩诺沙星按照0、20、40、60、80和100mg/kg浓度,对小体鲟及史氏鲟口服给药5d,停药两天后对其肝脏组织中微粒体蛋白浓度及细胞色素P450（cytochrome P450,CYP P450）酶活性进行测定。实验结果表明：两种鲟体内均含有一定量的P450酶,且史氏鲟体内微粒体蛋白浓度5.029 mg/g及P450酶活性0.102 nmol/mg?min均高于小体鲟相应的4.833 mg/g和0.088 nmol/mg?min。而恩诺沙星对史氏鲟及小体鲟体内的细胞色素P450酶活性均有一定抑制作用,随着给药浓度从0mg/kg到100mg/kg的增加,两种鲟体内的酶活性均逐渐降低,且史氏鲟体内P450酶活性降低幅度明显大于小体鲟,至100mg/kg给药组,两者差值仅为0.003 nmol/mg?min。上述结果对于探讨恩诺沙星在两种鲟体内的药物代谢及其与细胞色素P450酶之间相互作用的机制提供一定的理论依据。     

Resistance and virulence in the soybean-<Emphasis Type="Italic">Aphis glycines</Emphasis> interaction

Aphis glycines Matsumura, the soybean aphid, first arrived in North America in 2000 and has since become the most important insect pest of domestic soybean, causing significant yield loss and increasing production costs annually in many parts of the USA soybean belt. Research to identify sources of resistance to the pest began shortly after it was found and several sources were quickly identified in the USDA soybean germplasm collection. Characterization of resistance expression and mapping of resistance genes in resistant germplasm accessions resulted in the identification of six named soybean aphid resistance genes: Rag1, rag1c, Rag2, Rag3, rag4, and Rag5 (proposed). Simple sequence repeat markers flanking the resistance genes were identified, facilitating efforts to use marker-assisted selection to develop resistant commercial cultivars. Saturation or fine-mapping with single nucleotide polymorphism markers narrowed the genomic regions containing Rag1 and Rag2 genes. Two potential NBS-LRR candidate genes for Rag1 and one NBS-LRR gene for Rag2 were found within the regions. Years before the release of the first resistant soybean cultivar with Rag1 in 2009, a soybean aphid biotype, named biotype 2, was found that could overcome the resistance gene. Later in 2010, biotype 3 was characterized for its ability to colonize plants with Rag2 and other resistance genes. At present, three biotypes have been reported that can be distinguished by their virulence on Rag1 and Rag2 resistance genes. Frequency and geographic distribution of soybean aphid biotypes are unknown. Research is in progress to determine the inheritance of virulence and develop DNA markers tagging virulence genes to facilitate monitoring of biotypes. With these research findings and the availability of host lines with different resistance genes and biotypes, the soybean aphid-soybean pest-host system has become an important model system for advanced research into the interaction of an aphid with its plant host, and also the tritrophic interaction that includes aphid endosymbionts.     

硝酸还原酶活力与作物耐肥性的研究 Ⅲ.北方粳稻品种演变过程中硝酸还原酶活力与品种性状之间的关系

对北方粳稻栽培品种演变过程中品种性状和硝酸还原酶活力变化的研究表明:1)品种性状在演变过程中有了明显的变化,即从大穗高秆向多穗矮秆的方向变化;2)品种抗倒耐肥性变化的总趋势是由弱到强,其硝酸还原酶活力从高到低的变化。这就是说过去老品种大穗高秆,不抗倒不耐肥,硝酸还原酶活力高,而目前推广品种多穗矮秆,抗倒耐肥,硝