山东省麦红吸浆虫发生环境的初步分析

本初步分析丁山东省麦红吸浆虫发生的环境条件．结果表明．毗邻四省是麦红吸浆虫的高发区．为扩散到我省提供了虫源条件．鲁南各有虫县常年的4月上旬～5月上旬的温度和麦田湿度有利于麦红吸浆虫的化蛹和羽化．麦红吸浆虫成虫峰期和小麦抽穗期相吻合．为麦红吸浆虫产卵提供了条件．小麦品种混杂,增加了田间感虫机会．地膜蒜地形成了麦红吸浆虫的早期虫源．田间种群数量的积累．666停用后没有很好的替代土壤处理药剂．也是有利于麦红吸浆虫发生的条件．     

小麦品种抗麦红吸浆虫鉴定与抗性分析

利用一套较完整的田间自然感虫鉴定法,对183份小麦品种进行了抗麦红吸浆虫鉴定.鉴定结果表明,小麦不同品种对麦红吸浆虫的抗性存在着显著差异:高抗、中抗、低抗、感虫、高感的小麦品种,分别占参试品种的24.59%、16.94%、18.58%、14.21%、25.68%.不同抗性类型的小麦品种其穗被害率、粒被害率、估计损失率、抗性指数均有较大的差异,其中表现高抗类型45份,中抗类型31份.这些品种既可作为麦红吸浆虫发生区控制麦红吸浆虫危害的主推品种和后备品种,也可作为亲本材料提供给育种单位利用.     

麦红吸浆虫随气流远距离扩散的轨迹分析

为了解麦红吸浆虫Sitodiplosis mosellana (Géhin)种群随气流远距离扩散的可能性和扩散方向, 本研究于2010年5月在河南省洛阳市洛宁县, 利用系留气球携带取样器调查了麦红吸浆虫种群在5~75 m高空的分布以及活动节律, 应用HYSPLIT-4大气扩散模型模拟了2010年以洛宁县(34.35°N, 111.52°E)为起始点, 空中不同高度层麦红吸浆虫种群的扩散轨迹, 以及2007年麦红吸浆虫种群在我国北方麦区的扩散轨迹。结果表明: 在成虫发生期, 麦红吸浆虫在空中5, 45, 50和65 m 4个高度层种群密度较大, 表现出了明显的成层效应。2010年河南洛宁迁入的种群来自西南方的河南南阳地区, 迁出种群能够随气流进入东北方向的河南省宜阳县境内。2007年麦红吸浆虫种群能够随小麦发育期的先后, 随西南气流逐步向东北方向扩散。成虫随气流扩散是麦红吸浆虫种群远距离扩散的一种重要方式。研究结果有助于了解我国麦红吸浆虫远距离扩散方式, 同时对优化发生动态监测和综合治理提供参考。     

黑光灯诱集麦红吸浆虫成虫的数量及性比的变化

在河南省洛宁县小麦田夜间用黑光灯诱集麦红吸浆虫Sitodiplosis mosellana（Gehin）成虫,结果表明黑光灯对麦红吸浆虫成虫有极强的吸引作用,2010年4月30日至2010年5月19日之间日累计灯诱数量在9～5661头之间。5月7日是麦红吸浆虫发生的最高峰,当晚从20：00-23：30累计灯诱数量多达5661头;20：00以前天未完全黑,麦红吸浆虫成虫对黑光灯灯光不太敏感,灯诱数量较少;21：00-21：30时间段是麦红吸浆虫成虫夜间灯诱的高峰期,监测期间该时间段累计灯诱4134头;22：30以后吸浆虫活动显著减少。每晚灯诱数量与当日田间黄色粘板捕捉数量、网捕数量具有显著的相关关系,诱集到的红吸浆虫性比偏向雌性,表明黑光灯可以用作麦红吸浆虫成虫的监测工具。     

小麦品种（系）对麦红吸浆虫抗性指标筛选与抗性评价

【目的】筛选小麦对麦红吸浆虫Sitodiplosis mosellana抗性的准确鉴定方法, 明确生产上栽培小麦品种（系）对吸浆虫的抗性, 为抗虫小麦品种的筛选和利用提供科学依据。【方法】2012-2014年在陕西周至县建立麦红吸浆虫抗性鉴定圃, 调查并分析各参试小麦材料的估计损失率、粒被害率、穗被害率、单穗虫口和实际产量损失率及其相关性, 筛选出较准确的指标; 并以筛选到的指标为依据, 评估参试材料的抗性。【结果】估计损失率连续两年与其他3个抗性指标及实际产量损失率的相关性最强, 且均达到极显著水平。2012-2013年参试的85份和2013-2014年评估的80份材料中, 高抗、中抗和低抗材料合计分别为25份和40份; 重复种植的16份材料中, 14份两年均表现为抗性, 其中科农1006和晋麦47连续表现为高抗。【结论】估计损失率为具代表性且较准确的吸浆虫抗性鉴定指标。筛选出的抗性材料可作为抗吸浆虫的主推品种或后备品种, 也可作为亲本材料进行抗性育种研究。     

不同抗性小麦品种上麦红吸浆虫幼虫的空间分布型与理论抽样数

【目的】为了解小麦品种抗性对麦红吸浆虫Sitodiplosis mosellana(Géhin)幼虫在麦穗上空间分布型的影响,为科学调查提供合理的抽样依据。【方法】2015年5月采用剥穗调查法对陕西省周至县试验田种植的4个抗虫和4个感虫小麦品种麦红吸浆虫幼虫危害进行调查,应用6种聚集度指标和Iwao M*?m回归法综合分析了幼虫在抗性不同小麦品种上的的空间分布结构。【结果】幼虫在抗、感小麦品种整穗及麦穗上、中、下部位上空间分布型一致,均呈聚集分布,但在抗虫品种上聚集强度大于感虫品种;抗、感小麦品种上分布的基本成分均为个体群,个体间相互吸引。聚集均数λ分析表明,幼虫在抗性较强品种上的聚集主要由小麦穗部化学物质和形态结构等环境因素引起,感虫品种上则由环境因素和成虫的产卵习性共同作用所致。幼虫在抗、感小麦品种上的发生趋势一致,均是上部发生最重,中部次之,下部最轻。根据Iwao回归法中的分布型参数,确立了幼虫在不同虫口密度和允许误差条件下的理论抽样数。【结论】麦红吸浆虫幼虫在抗性不同小麦品种上均呈聚集分布,调查时应根据当地栽培品种平均虫口密度选择适宜的抽样数量。     

麦红吸浆虫在我国的发生、危害及防治

麦红吸浆虫Sitodiplosis mosellana是我国的一种重要农业害虫, 以幼虫危害小麦正在发育的籽粒, 可造成小麦严重减产, 甚至绝收。该害虫具有虫体小, 滞育时间长, 为害隐蔽等特点。近些年来, 受全球气候变化、 耕作制度改变、 小麦品种更换、 人类活动等多种因素的影响, 麦红吸浆虫在我国的发生危害情况发生了很大变化, 出现了北扩东移的现象。麦红吸浆虫主要分布在我国的北方麦区, 发生为害具有隐蔽性、 间歇性、 局部性和暴发性的特点。这种害虫的发生危害受虫源基数、 生态因子、 农业生产措施及人类活动等多种因素的影响。进入21世纪后, 麦红吸浆虫在我国的发生范围发生了很大的变化, 且主要分布在43°N以南到27°N以北的冬小麦主产区。有关麦红吸浆虫滞育的多态性、 小麦对麦红吸浆虫的抗性机理、 抗性品种的选育和天敌资源的开发等方面的研究将是今后的主要研究方向; 未来仍需加强对麦红吸浆虫滞育的分子机制、 发生危害规律、 预测预报、 综合防治和寄主植物 麦红吸浆虫 天敌三级营养关系等方面研究。本综述可为今后了解麦红吸浆虫在我国的发生危害规律、 预测预报及综合防治等提供参考。     

麦红吸浆虫成虫对线偏振光的趋性

【目的】本研究旨在探索麦红吸浆虫Sitodiplosis mosellana对线偏振光的趋光效果。【方法】在室内采用自行设计的Y-型管装置,测试了麦红吸浆虫成虫对线偏振光与非偏振光的选择差异,并利用线偏振光诱捕装置进行了田间对比试验。【结果】结果显示,麦红吸浆虫成虫对线偏振光与非偏振光的趋光选择率分别为47.23%和20.31%,且二者之间差异显著;田间设置线偏振光与非偏振光紫外灯对麦红吸浆虫成虫的诱集量分别为:水平线偏振光(60.20)垂直线偏振光(37.60)非偏振光(25.60),且水平线偏振光与非偏振光源对麦红吸浆虫的诱集量具有显著差异。【结论】麦红吸浆虫对线偏振光具有较强的偏好性;水平线偏振紫外光诱捕装置与非偏振相比,对麦红吸浆虫有较强的诱集效果。     

耕作方式对麦红吸浆虫种群动态的影响

为了解不同耕作方式对麦红吸浆虫Sitodiplosis mosellana （Géhin）种群动态的影响, 2010年和2011年, 在中国科学院河北省栾城农业生态系统试验站不同耕作方式的小麦样地中, 通过淘土、 成虫网捕和剥穗等方法对麦红吸浆虫进行了调查研究。结果表明： 两年取土筛检出的幼虫数量依次为秸秆还田免耕田>秸秆站立免耕田>秸秆还田旋耕田, 但2011年网捕调查显示, 秸秆还田旋耕田中的成虫数量高于另外两种样地。两年剥穗检查出的幼虫数量的排序与取土筛检出的幼虫数量的排序相反, 依次为秸秆还田旋耕田>秸秆站立免耕田>秸秆还田免耕田。分析表明免耕有利于幼虫的越冬, 但免耕田麦穗受害较轻。旋耕对幼虫越冬不利, 但抽穗后受害较严重。在耕种方式是旋耕的情况下, 漫灌可加重吸浆虫的危害。研究结果有助于进一步了解大范围耕作方式的变迁对麦红吸浆虫发生的影响。     

太行山前平原麦田昆虫种类调查及4种药剂对麦红吸浆虫的药效实验

以藁城为例,采用淘土、扫网、挂黄板等方法对太行山前平原麦田昆虫群落进行了调查,结果表明该区域超高产麦田昆虫种类相对较少,总计22种,隶属于6目14科。害虫主要有2类,吸浆虫类和麦蚜类。小麦吸浆虫以麦红吸浆虫为主。天敌昆虫常见有蚜茧蜂、食蚜蝇、草蛉和瓢虫4类。采用氧乐果、毒死蜱、高效氯氰菊酯、吡虫啉4种常用药剂对麦红吸浆虫成虫进行了田间药效实验,结果表明上述4种药剂对麦红吸浆虫均有较好的防治效果,虫口减退率均在80%以上。其虫口减退率从高到低依次为:氧乐果、毒死蜱、高效氯氰菊酯、吡虫啉。建议根据麦红吸浆虫的发生情况,选择中低毒药剂毒死蜱、高效氯氰菊酯、吡虫啉交替使用。     

The 5S DNA units of bread wheat (Triticum aestivum)

A collection of 44 cloned 5S DNA units fromTriticum aestivum cv. Chinese Spring were grouped into 12 sequence-types based on sequence similarity and the respective consensus sequences were then produced. The relationship between these 12 consensus sequences (T. aestivum S 1-S 8 andT. aestivum L 1-L 4), together with two clones sequenced byGerlach andDyer, and the 5S DNA consensus sequences from diploidTriticum spp. were then determined by numerical methods. Both phenetic and cladistic analyses were carried out. The following wheat 5S DNA sequences were found to group with respective sequences from diploidTriticum spp.:T. aestivum S 4, S 6 withT. tauschii S;T. aestivum S 3 withT. monococcum S andT. monococcum S-Rus 7;T. aestivum L 1 andT. aestivum L-G&D withT. speltoides L;T. aestivum L 2, L 3 withT. tauschii L;T. aestivum L 4 withT. monococcum L andT. monococcum L-Rus 12. The analyses suggested that 5 out of the 65S Dna loci present in wheat were identified at the sequence level. The locus that could not be identified in this analysis was the5S Dna-B 1 locus. A group ofT. aestivum sequences (T. aestivum S 1, S 7, S 8, S-G&D) were found to be distinct from the other 5S DNA sequences in the data base. The existence of the distinct group of 5S DNA sequences suggests that there is a gap in our current understanding of wheat evolution with respect to the5S Dna loci.     

Genetics of yellow berry in wheat (Triticum aestivum)

Summary The inheritance of yellow berry, a grain disorder in durum and bread wheats, was studied in six intervarietal crosses in bread wheat. The trait was found to be controlled by either two or three dominant genes. Monosomic analysis using Chinese Spring monosomic series showed the presence of two major dominant genes on chromosomes 1A and 7A, and four modifiers on 4A, 4B, 6A and 6D, which influence the expression of yellow berry in bread wheat.     

Carbon monoxide sensitivity of cytochrome oxidase in wheat leaves in relation to dwarfing genes (Rht) in wheat cultivars

Summary Leaves of young seedlings of a number of tall cultivars of wheat, lacking the dwarfing Rht genes, readily responded to a brief 2 min exposure to CO, as assessed by in vivo aerobic assay of nitrate reductase. This test depends on the inhibition of cytochrome c oxidase by CO, which in turn renders cytosolic NADH available for the reduction of nitrate to nitrite in vivo. Semi-dwarf cultivars of wheat (Rht present) did not respond to CO in this way. Since CO forms a complex only with reduced cytochrome a₃, the results indicate differences in the redox state of cytochrome a₃, during in situ respiration of leaves from tall and semi-dwarf plants which are likely to be under genetic control.     

Regeneration of fertile wheat (Triticum aestivum) plants from isolated zygotes using wheat microspore culture as nurse cells

A new method for growing isolated wheat zygotes by co-cultivation with microspores isolated from the same species has been developed. Although the mortality of isolated zygotes within 6 h after the transfer into the nurse culture was relatively high (70%) in this method, the majority of the structures which survived developed into fertile plants (61%). Zygotic structures grown in these cultures were morphologically not as regular as embryos grown in planta, but they resembled them closely in cytological properties and developmental pattern.     

Modelling potassium uptake by wheat (Triticum aestivum) crops

Spring wheat was grown in the field under deficient and sufficient levels of soil K and with high and low supplies of fertiliser nitrogen. Measurements were made of K uptake, soil nutrient supply parameters, root growth and, in solution culture, root influx parameters. Mechanistic models predicted uptake reasonably well under K-deficient conditions, but over-predicted uptake, by as much as 4 times, under K-sufficient conditions. The over-prediction was apparently due to poor characterisation of plant demand.     

Effect of Eucalyptus and Mentha leaves and Curcuma rhizomes on Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae) in wheat

Varying concentrations of powdered leaves of Eucalyptus and Mentha and rhizomes of Curcuma were evaluated in controlling Tyrophagus putrescentiae in wheat flour. At higher concentrations, all these plant materials significantly decreased the population build-up of the mite. Eucalyptus and Mentha leaf powders were effective at concentrations ranging from 100 to 5% in bringing about a decrease in the fecundity of the mite and reducing the egg numbers to 51.66 and 25.49 per female, respectively, as compared to 98.16 eggs per female in the controls. Rhizomes of Curcuma were effective even at a concentration of 0.1% reducing the egg laying to 7.66 eggs per female in wheat flour. These materials were more deleterious to immature stages (ova and larvae) than to the mature stages of T. putrescentiae. When tested on whole grains of wheat these plant materials showed more pronounced effects in controlling the mite population compared to that in wheat flour. Curcuma rhizomes were the most promising for possible use against T. putrescentiae.     

Intrachromosomal mapping of crossability genes in wheat (Triticum aestivum)

Summary Intrachromosomal mapping studies were used to locate the positions of the genes Kr1 and Kr2, which control the crossability of wheat with Hordeum bulbosum, on chromosomes 5B and 5A, respectively. The location of Kr1 was established using the telocentric mapping technique and found to be on the long arm of chromosome 5B, distal to the centromere with a mean recombination frequency of 44.8±3.28%. Kr2 was located on the long arm of chromosome 5A by linkage with the major gene markers Vrn1, controlling vernalization requirement, and q, controlling ear morphology. Kr2 is closely linked to Vrn1, with a mean recombination frequency of 4.8±4.66%, and is distal to q with a mean recombination frequency of 38.1±10.60%. The similar locations of Kr1 and Kr2 on homoeologous chromosomes suggest that these two loci are homoeoallelic. Significant correlations between Hordeum bulbosum and rye crossability confirmed that Kr1 and Kr2 control the crossability of wheat with both species.     

Principal component analyses of bagged wheat infested withSitotroga cerealella (Lepidoptera: Gelechiidae) andSitophilus oryzae (Coleoptera: Curculionidae)

Interrelations among biological and abiological variables over 22 weeks at 28°C and 60% RH were revealed by principal component analysis (PCA) on data collected from simulated bagged wheat (Triticum aestivum L.) which was not infested by insects (control system), was infested bySitophilus oryzae (L.) (SO system), bySitotroga cerealella (Olivier) (SC system) or by both species (SC+SO system). The variables measured were temperature, grain moisture, CO₂, dust weight, fat acidity value, grain weight, germination, insect numbers and frequency of occurrence of microfloral species. The analysis indicated the interrelations among variables involved in degradation of the wheat. In the control system, the dominant interrelations were those among abiological variables, indicating that deterioration of the wheat was minimal. In the SO system, principal components which represented insect effects, seed quality and temperature-fungal relationships, were predominant. Similar factor-loading patterns were extracted both in the SC and SC+SO systems; the principal components suggested thatS. cerealella was mainly responsible for heavy deterioration of the wheat. The principal components, which were rotated orthogonally by 45δ, indicated that the process of wheat degradation in both systems proceeded gradually until week 10 or 15 and thereafter the rate of degradation was accelerated and serious grain quality loss occurred.     

Impact of intercropping aphid-resistant wheat cultivars withoilseed rape on wheat aphid (Sitobion avenae) and its natural enemies

The effects of intercropping of wheat cultivars and oilseed rape on the densities of wheat aphid, Sitobion avenae, and their arthropod natural enemies were evaluated. Three winter wheat cultivars with different resistant levels to S. avenae were used: ‘KOK’ (high resistance), ‘Xiaobaidongmai’ (low resistance) and ‘Hongmanghong’ (susceptible). The results showed that the densities of S. avenae were significantly higher on the monoculture pattern than on either the 8-2 intercropping pattern (eight rows of wheat with two rows of oilseed rape) or the 8-4 intercropping pattern (eight rows of wheat with four rows of oilseed rape). The mean number of predators and the mummy rates of S. avenae were significantly higher in two intercropping patterns than those in the monoculture pattern. The densities of S. avenae, ladybeetles, and mummy rate of S. avenae were significantly different among different wheat cultivars. The highest densities of S. avenae and ladybeetles were found on wheat cultivar Hongmanghong. The lowest densities of S. avenae associated with high mummy rate of S. avenae were found on wheat cultivar Xiaobaidongmai. The results showed that wheat-oilseed rape intercropping conserved more predators and parasitoids than in wheat monoculture fields, and partial resistance of wheat cultivar Xiaobaidongmai had complementary or even synergistic effects on parasitoid of S. avenae.     

Genetic analysis of Karnal bunt (Neovossia indica) resistance in wheat

Embryos excised from seeds of six generations (P₁, P₂, F₁, BC₁, BC₂ and F₂) of a cross WH 283 x WH 533 were cultured on modified MS medium already inoculated with secondary sporidia ofNeovossia indica. Significant variations for callusing response (CR) (54.55–75.55%) were observed among generations but the presence or absence ofN. indicia did not affect callusing response. A clear inhibition zone (IZ) was formed around each embryo showing callusing. The diameter of IZ varied significantly among generations and was maximum in the resistant genotype, WH 283 (3.60 cm). Fresh weight and dry weight of calli, initiated from embryo cultured and inoculated withN. indica, varied significantly among generations. Coefficient of infection as well as percentage of infection reflected the overdominance of susceptibility. Generation mean analysis showed that the three parameter model was adequate for diameter of IZ only. Six-parameter model showed that additive (in presence ofN. indica), additive and additive x dominance (in absence ofN. indica) effects were also significant. Complementary type of epistasis for fresh weight of calli and dominance, and dominance x dominance effects for dry weight of calli were observed in the presence ofN. indica. Magnitude of additive effects was higher for diameter of IZ in three parameter model. Therefore, selection might assist in improving this trait and thus indirectly help in attaining the resistance towardsN. indica.