基于模糊识别和刺探电位技术鉴定小麦种质资源抗蚜性

利用田间抗蚜性鉴定模糊识别技术,结合室内刺探电位(EPG)植物抗性鉴定技术,比较分析了不同遗传背景的小麦种质资源的抗蚜性,为筛选新型小麦抗蚜种质材料提供依据。2年田间抗蚜性鉴定结果表明: 小偃麦多表现为中抗或低抗,而小黑麦多为中感或低感。选取抗性性状稳定且抗性级别不同的小偃麦21(中抗)、小偃麦22(低抗)、小黑麦31(中感)和小黑麦32(低感)进行麦长管蚜取食行为分析。对非刺探波(Np)、刺探波(P)、电势落差(Pd)、水溶性唾液分泌波(E1)、韧皮部取食波(E2)、细胞机械阻碍波(F)和木质部取食波(G)等基本波形的分析显示,麦长管蚜在小偃麦上首次开始刺探的时间显著长于小黑麦,且在小偃麦上的E1波的持续时间显著大于小黑麦;麦长管蚜在小偃麦21上的F波和小偃麦22上Np波的持续时间最长,在小黑麦31上的P波和小黑麦32上的G波的持续时间最长。以E1、F和Np波的持续时间为指标,基于刺探电位的小麦种质资源抗性水平鉴定结果与田间鉴定结果基本一致。因此,使用EPG技术筛选抗蚜小麦材料时,建议采用E1、F和Np波作为评价小麦抗性水平的指标。小偃麦21、22对麦长管蚜的抗性水平较高,可作为小麦抗蚜育种的种质材料。     

小麦品种抗性对麦长管蚜种群增长的影响

本研究采用室内、外结合的方法,分苗期和拔节期,对大田抗蚜性鉴定中表现不同的10个小麦品种的抗性对麦长管蚜种群增长的影响进行了研究。研究结果显示,品种抗性对麦长管蚜的存活率、发育进度、繁殖力有一致的抑制作用;品种间抗蚜性存在显著差异。同时通过组建不同品种上麦长管蚜繁殖特征生命表,从量的角度揭示了小麦品种抗性与麦长管蚜种群增长之间的关系。     

小麦抗蚜品种（系）或材料的抗性遗传测定及筛选

测定了部分小麦品种（系）或材料的丁布（ＤＩＭＢＯＡ）含量及几个和抗蚜性有关的物理性状（叶、叶毛长度和密度,蜡质含量）,同时对这些品种（系）或材料进行抗麦长管蚜（Ｍacrosiophum avenae(F.))鉴定,统计其累计蚜量。结果表明,丁布含量及各物理性状与累计蚜量均成负相关关系,通过多目标综合决策分析,认为１粒小麦（Ｔriticum monococcum)和材料９８－１０－９是比较好的抗性种质资源,生产上广泛推广的千斤早是感蚜的品种。     

主要抗蚜小麦品种(系)的抗性类型及其生化抗性机制

通过对10个抗麦蚜品种(系)室内苗期生命参数、抗性类型和抗蚜次生物质的研究,明确了不同抗性级别的品种对麦蚜种群控制力及部分生化抗蚜机制。实验结果表明,参试的抗蚜品种(系)中30%左右为不选择性：表现为爬行频繁,定殖率低,但是定殖个体生长发育良好;70%为抗生性;表现为使麦长管蚜Sitobion avenae(F.)和禾谷缢管蚜只Rhopalosiphum padi(L.)的发育历期分别延长2.1%～28.2%和3.7%～13.9%,若蚜死亡率增加1.0～3.6倍和1.0～2.25倍,平均寿命缩短10.2%～96.5%和37.5～97,1%,繁殖力下降3.4%～72.8%和25%～97.2%。苗期生化测定结果表明：不同抗源的单宁和总酚含量明显高于感蚜品种,其总酚含量与抗麦长管蚜级别呈显著负相关,以抗生性为主的品种其总酚含量亦与麦长管蚜的内禀增长力(r_m)呈显著负相关(P<0.05),表明总酚是小麦抗长管蚜的关键因子之一,而与禾谷缢管蚜抗性水平无关;单宁含量与麦蚜抗性关系不密切。     

3个新引进小麦品种对麦长管蚜抗性的初步研究

以小偃-22和Amigo(美国)为对照对麦长管蚜在3个新引进小麦品种Astron、Batis和Xanthos(德国)上的抗蚜性进行了测定。在室内控制条件下,麦长管蚜在5个品种上的发育历期(DD)、体重差(dW)、相对日均体重增长率(MRGR)和生殖力(F)的测定结果表明,Astron、Xanthos与Amigo、小偃-22的抗性水平相当,均优于Batis;在大田自然条件下,通过对不同品种在不同生育期的感蚜指数以及感蚜量动态曲线的监测分析表明,Astron、Xanthos在我国的抗蚜水平与抗性品种Amigo的抗蚜性水平相当,优于Batis和小偃-22。可初步说明Astron、Xanthos在我国也具有较好的抗蚜性,可作为我国抗蚜育种材料。     

我国小麦抗麦长管蚜(Sitobion avenae)研究概况

麦长管蚜是我国小麦的重要害虫之一。选育和种植抗虫品种是防治麦长管蚜的理想方法。本文就我国小麦抗麦长管蚜种质资源筛选、抗性机制和小麦品种对麦蚜种群动态影响等方面的研究进展进行了概括,同时指出今后应加强小麦抗麦长管蚜基因的研究。     

抗青枯病烟草种质资源在云南省的评价

筛选出抗性稳定的种质资源是选育抗病品种的重要基础。本文采用人工接种和病田自然发病方法鉴定了48份烟草种质的青枯病抗性表现。土壤盆栽接种鉴定表现为高抗的材料有CF207、岩烟97、TI448A、DB101、G80、RG17、GTH-1等7份材料,表现抗病的有MSK149、Oxford 2028、NC95、YN108、K346、K358、Enshu FC、Oxford 207、RG11等9份材料。苗期恒温水培接种鉴定结果表明,Oxford 207和岩烟97表现为高抗,Enshu FC表现抗病,抗病材料与云烟85和K326杂交F1的抗性表现为中感至抗病。田间自然发病鉴定结果表明,我国审定的中抗青枯病的品种RG17、RG11、K358和K346,在云南省田间抗性表现为中抗,产值较高。TI448A田间表现为抗青枯病,但易感黑胫病和空茎病。Oxford 2028和Oxford 207田间表现为抗病至高抗,产值较高。G3和岩烟97田间分别表现为高抗和抗病,产值较低。根据接种鉴定和田间病圃2年抗性鉴定,筛选出育种潜力较大的青枯病抗源Oxford 207、Enshu FC,岩烟97和TI448A。     

不同小麦品种（系）对麦长管蚜的抗性

采用网罩麦长管蚜Sitobion miscanthi (Takahashi)的观测方法,对15个不同抗性小麦品种（系）进行苗期不选择性、抗生性测定;选择其中5个代表性品种（系）观测了田间扬花期麦长管蚜的产蚜量,测定了小麦旗叶和穗部中单宁与槲皮素的含量以及麦长管蚜羧酸酯酶（CarE）与谷胱甘肽S-转移酶（GST）的活性。结果表明,代表性品种（系）在苗期对麦长管蚜的产蚜量的影响与扬花期的呈显著正相关（r＝0.956*）。穗部槲皮素的含量与不同抗性品种（系）上的产蚜量呈显著负相关（r＝-0.941*）;单宁含量在不同抗性品种（系）间存在显著差异,其含量变化与产蚜量无显著相关。取食不同抗性品种（系）后麦长管蚜的CarE和GST酶活力存在显著差异。结论认为小麦不同品种（系）对麦长管蚜产蚜量（生殖力）的抑制作用是其抗蚜的重要特性,尤其是中4无芒和冀保一号对麦长管蚜抗生性较强。     

春小麦品种对麦长管蚜生长发育和繁殖的影响

在室内25 ℃条件下研究了7种不同抗性的春小麦品种（系）对麦长管蚜生长发育和繁殖的影响.结果表明,不同抗性品种（系）对麦长管蚜若蚜发育历期、存活率、成蚜寿命和生殖力有显著的影响,麦长管蚜在抗性强的品种上成蚜寿命短、产仔量少;以内禀增长率作为测定抗生性的指标,供试小麦品种（系）对麦长管蚜抗生性的大小依次为辽春10号>02C-MB >新春6号>巴丰1号>永良4号>内麦19>蒙花1号,与田间抗性鉴定结果基本相同.     

小麦种质对茎基腐病抗性评价及优异种质筛选

小麦茎基腐病是由镰孢菌侵染引起的一种世界性土传病害,近年来已严重威胁到我国小麦的安全生产。为筛选具有茎基腐病抗性的小麦种质资源,本研究采用孢子悬浮液浸种法,分别以国外抗病材料Sunco和中国品种陕253为抗病和感病对照,对670份我国小麦品种(系)进行了茎基腐病温室苗期抗性鉴定。结果发现,我国供试品种(系)感病材料(病情指数>30)所占比例达到84%,且包含多个近年来小麦生产中的主推品种,表明我国小麦品种总体抗性水平低是导致茎基腐病近年来发病频率与程度不断增加的重要原因之一。经多轮筛选,发掘获得15份抗病表现稳定、抗性水平与抗病对照Sunco相仿的材料。15份材料平均病情指数在10.9~19.4之间,其株高、抽穗期等农艺性状表现出较为丰富的变异,为我国小麦抗茎基腐病品种选育和抗性遗传研究提供了种质资源。     

西瓜种质资源抗旱性苗期筛选与评价

采用苗期持续干旱法,对1066份西瓜种质资源开展大规模抗旱性筛选评价。结果表明,不同基因型种质资源抗旱性差异明显。采用快速聚类方法将供试材料分为抗旱、耐旱、敏感和抗性分离等4种类型,共获得25份强抗旱性西瓜材料,多为来源于非洲的野生西瓜种质资源,适用于西瓜嫁接砧木的选育;获得30份中等抗旱性材料,多为栽培种西瓜种质资源,具有农艺性状优良、抗病性强等优点,可直接用于抗旱节水西瓜新品种选育。     

Patterns of resistance to three cereal aphids among wheats in the genus Triticum (Poaceae)

Forty-one accessions of wild and cultivated wheats belonging to 19 Triticum species were tested in the field for resistance to three species of aphids, Rhopalosiphum padi Linnaeus, Sitobion avenae Fabricius and Schizaphis graminum Rondani. Antibiotic resistance was estimated by the increase in biomass of aphids over 21 days on adult plants. Overall resistance was estimated by the plant biomass lost due to aphid infestation. All three species of aphids survived and reproduced on all wheats, and reduced spike biomass compared to uninfested controls. The level of antibiosis varied among wheat species and among accessions, with accessions from three, five and one species showing antibiosis to R. padi, S. avenae and S. graminum, respectively. Overall resistance to the three aphid species was observed in five to seven accessions per aphid species. Resistance was usually specific to one aphid species. The frequency of accessions with antibiosis or overall resistance was associated with the ploidy level of the plant species. Except for overall resistance to R. padi, resistance was highest for diploid species and lowest for hexaploid species. No consistent relationship between resistance and level of domestication was detected. Accessions of the wild wheats, Triticum boeoticum Bois, Triticum tauschii (Coss.) Schmal. and Triticum araraticum Jakubz. exhibited high levels of resistance to aphids, as did Triticum monococcum L. which is derived from T. boeoticum. Nevertheless, individual susceptible or resistant accessions occurred at all levels within the evolutionary tree of wheat.     

Seedling and adult plant resistance to Sitobion avenae (Hemiptera: Aphididae) in Triticum monococcum (Poaceae), an ancestor of wheat

Cereal aphids are important pests of wheat, Triticum aestivum L. and Triticum durum Desf. Crop resistance is a desirable method for managing cereal aphids in central North America, where the dominant crop, spring-sown wheat, has a low value per unit area. A diploid ancestor of wheat, Triticum monococcum L., is reported to be partially resistant to Sitobion avenae (Fabricius), the most damaging cereal aphid in the region. To identify potential sources of resistance, 42 accessions of T. monococcum and three cultivated wheats were infested with aphids, seedlings for six days and adult plants for 21 days. Overall resistance was estimated by the biomass loss of foliage and spikes in relation to uninfested control plants. Antibiosis was estimated by the gain in biomass of aphids during infestation, and tolerance was estimated as a biomass conversion ratio, overall resistance divided by antibiosis. A few T. monococcum accessions exhibited partial resistance. No relationship was found between seedling and adult plant resistance: the former exhibited primarily antibiosis and the latter primarily tolerance. Two accessions with antibiosis reduced aphid biomass by 60% compared with commercial wheats. Tolerance was correlated with growth potential, and was useful only in accessions with high growth potential. Four accessions exhibited tolerance levels at least 30% greater than commercial wheats. Highly susceptible accessions also were identified, which would be useful for investigating the inheritance of antibiosis and tolerance.     

Phenotypic mechanisms of host resistance against greenbug (Homoptera: Aphididae) revealed by near isogenic lines of wheat

Interactions between biotype E greenbug, Schizaphis graminum (Rondani), and wheat, Triticum aestivum L., were investigated using resistant and susceptible near isogenic lines of the greenbug resistance gene Gb3. In an antixenosis test, the greenbugs preferred susceptible plants to resistant ones when free choice of hosts was allowed. Aphid feeding resulted in quick and severe damage to susceptible plants, which seemed to follow a general pattern spatially and was affected by the position where the greenbugs were initially placed. Symptom of damage in resistant plants resembled senescence. Within-plant distribution of aphids after infestation was clearly different between the two genotypes. Significantly more greenbugs fed on the first (oldest) leaf than on the stem in resistant plants, but this preference was reversed in the susceptible one. After reaching its peak, aphid population on the susceptible plants dropped quickly. All susceptible plants were dead in 10-14 d after infestation due to greenbug feeding. Aphid population dynamics on resistant plants exhibited a multipeak curve. After the first peak, the greenbug population declined slowly. More than 70% of resistant plants were killed 47 d after infestation. Performance of both biotype E and I greenbugs on several Gb3-related wheat germplasm lines were also examined. It seems that the preference-on-stem that was characteristic of biotype E greenbugs on the susceptible plants was aphid biotype- and host genotype-dependent. Results from this study suggested that antixenosis, antibiosis, and tolerance in the resistant plants of wheat might all contribute to resistance against greenbug feeding.     

部分小麦近缘物种材料的白粉病抗性鉴定

鉴定了170份小麦近缘物种材料苗期对北京地区流行的小麦白粉菌小种的抗性表现,包括引自美国和欧洲的斯卑尔脱小麦81份,密穗小麦27份,中国的西藏半野生小麦4份,和引自 CIMMYT 的人工合成六倍体小麦58份。结果表明,3份斯卑尔脱小麦表现抗病,它们是瑞士品种 Hubel 和 Lueg 以及德国的原始品种69Z6.245(编号 PI348085)。人工合成六倍体小麦中有19份材料表现高抗至免疫。密穗小麦材料中有2份(即美国材料 DN-2263和 Coda)表现抗病。4份西藏半野生小麦苗期都不抗小麦白粉病。     

Laboratory selection for resistance to sulfoxaflor and fitness costs in the green peach aphid Myzus persicae

Sulfoxaflor is a newly released fourth-generation neonicotinoid insecticide for management of sap-feeding pests that have developed resistance to established insecticide groups. The risk of resistance developing to this pesticide in target pests is unclear. We selected a strain of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), for resistance to sulfoxaflor in the laboratory, which showed 199-fold resistance after 45 generations compared to the starting population. Life table analysis showed that the resistant strain had a fitness of 0.83 compared to the susceptible strain. Adult longevity of the resistant strain was reduced by 9.55% compared to the susceptible strain. The period when adults of the resistant strain produced offspring was reduced by 17.19%, while the mean fecundity of the resistant strain was reduced by 15%. These findings suggest that M. persicae can develop a high level of resistance to sulfoxaflor, but fitness costs may result in a recovery of sensitivity when field populations are no longer exposed to sulfoxaflor.     

Glycoproteins from Russian wheat aphid infested wheat induce defence responses

Elicitors are molecules which can induce the activation of plant defence responses. Elicitor activity of intercellular wash fluid from Russian wheat aphid, Diuraphis noxia (Mordvilko) infested resistant (cv Tugela DN), and susceptible (cv Tugela), wheat (Triticum aestivum L.), was investigated. Known Russian wheat aphid resistance related responses such as peroxidase and beta-1,3-glucanase activities were used as parameters of elicitor activity. The intercellular wash fluid from infested resistant plants contains high elicitor activity while that from infested susceptible plants contains no or very little elicitor activity. After applying C-18 reverse phase and concanavalin A Sepharose chromatography, elicitor active glycoproteins were isolated from the intercellular wash fluid of Russian wheat aphid infested resistant wheat. The elicitor-active glycoproteins separated into three polypeptides during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isolated glycoproteins elicited peroxidase activity to higher levels in resistant than in susceptible cultivars. It was evident that the glycoproteins were probably a general elicitor of plant origin. Information gained from these studies is valuable for the development of plant activators to enhance the defence responses of plants.     

Seasonal dynamics of cereal aphids on Russian wheat aphid (Homoptera: Aphididae) susceptible and resistant wheats

Field experiments were conducted in 1997 and 1998 to evaluate the impact of resistance to Russian wheat aphid, Diuraphis noxia (Mordvilko), on the cereal aphid complex in wheat. Two spring wheats were planted: the variety "Centennial" (Russian wheat aphid susceptible) and the advanced line IDO488 (Russian wheat aphid resistant). IDO488 incorporates the resistance found in PI 294994 into a Centennial background. Field plots were artificially infested with adult D. noxia and sampled weekly. The most abundant aphid species in 1997 were Metopolophium dirhodum (Walker), Sitobion avenae (F.), D. noxia, and Rhopalosiphum padi (L.). In 1998, the order of abundance was M. dirhodum, R. padi, S. avenae, and D. noxia. The resistant genotype had significantly fewer D. noxia than the susceptible one during both years. However, plant genotype had no significant effect on the other aphid species in either year. Both the initial density of D. noxia and plant growth stage, had a significant effect on D. noxia population development, but had no effect on the other aphid species. There was no interaction between D. noxia resistance and the population density of the other aphid species observed.     

Aphid populations showing differential levels of virulence on Capsicum accessions

The green peach aphid,Myzus persicae,is one of the most threatening pests in pepper cultivation and growers would benefit from resistant varietices.Previously,we identified two Capsicum acessions as susceptible and three as resistant to M.persicae using an aphid population originating from the Netherlands(NL).Later on we identified an aphid population originating from a diferent gcographical region(Switserland,SW)that was virulent on all tested Capsicum acessions.The objeetive of the current work is to describe in detail diferent aspects of the interaction between two aphid populations and two sclected Capsicum acessions(one that was susceptible[PB2013046]and one that was resistant[PB2013071]to population NL),including biochemical processes involved.Electrical penetration graph(EPG)recordings showed similar feeding activities for both aphid populations on PB2013046.On acession PB2013071 the aphid population sw was able to devote significantly more time to phloem ingestion than population NL.We also studied plant defense response and found that plants of acession PB2013046 could not induce an accumulation of reactive oxygen species and callose formation after infestation with either aphid population.However,plants of PB2013071 induced a stronger defense response after infestation by population NL than after infestation by population SW.Based on these results,population SW of M.persicae seems to have overcome the resistance of PB2013071 that prevented feeding of aphids from NL population.The potential mechanism by which SW population overcomes the resistance is discussed.     

Fractionated extracts of Russian wheat aphid eliciting defense responses in wheat

It is hypothesized that the interaction between aphids and plants follows a gene-for-gene model. The recent appearance of several new Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Homoptera: Aphididae), biotypes in the United States and the differential response of wheat, Triticum aestivum L., genotypes containing different resistance genes also suggest a gene-for-gene interaction. However, aphid elicitors remain unknown. This study was conducted to identify fractionated Russian wheat aphid extracts capable of eliciting differential responses between resistant and susceptible wheat genotypes. We extracted whole soluble compounds and separated proteins and metabolites from two Russian wheat aphid biotypes (1 and 2), injected these extracts into seedlings of susceptible wheat Gamtoos (dn7) and resistant 94M370 (Dn7), and determined phenotypic and biochemical plant responses. Injections of whole extract or protein extract from both biotypes induced the typical susceptible symptom, leaf rolling, in the susceptible cultivar, but not in the resistant cultivar. Furthermore, multiple injections with protein extract from biotype 2 induced the development of chlorosis, head trapping, and stunting in susceptible wheat. Injection with metabolite, buffer, or chitin, did not produce any susceptible symptoms in either genotype. The protein extract from the two biotypes also induced significantly higher activities of three defense-response enzymes (catalase, peroxidase, and beta-glucanase) in 94M370 than in Gamtoos. These results indicate that a protein elicitor from the Russian wheat aphid is recognized by a plant receptor, and the recognition is mediated by the Dn7-gene product. The increased activities of defense-response enzymes in resistant plants after injection with the protein fraction suggest that defense response genes are induced after recognition of aphid elicitors by the plant.