茶棍蓟马（Dendrothrips minowai Priesner）触角感器的扫描电镜观察

应用扫描电镜技术观测了茶棍蓟马若虫、蛹、雌雄成虫触角感器的类型、分布及超微结构。结果表明,各种虫态的茶棍蓟马触角上共存在9种感器：Böhm氏鬃毛（BB）、钟形感器（SCa）、锥形乳头状感器（BMS）、刺形感器（SCh）、锥形感器（SB）、腔锥形感器（SCo）、腔形感器（SCav）、耳形感器（SA）和特殊结构感器（US）。其中,刺形感器分3种亚型,锥形感器分4种亚型。若虫、蛹、雌、雄成虫的触角感器在触角上的种类和分布有较大的差异,雌虫上具8种感器,无锥形乳头状感器;雄虫上着生7种,缺少锥形乳头状感器和腔形感器;若虫上感器种类有8种,无耳形感器,独具锥形乳头状感器;蛹的感器类型及数量最少,只有2种,即刺形感器和锥形感器。     

Antennal Sensilla in the Parasitoid Sclerodermus sp. (Hymenoptera: Bethylidae)

Parasitoid wasps of the genus Sclerodermus (Hymenoptera: Bethylidae) are an important natural enemy of the Japanese pine sawyer beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae). In this study, we used scanning electron microscopy to examine the external morphology of the antennal sensilla of Sclerodermus sp. Antennae of females and males comprised the scape, pedicel, and 11 flagellomere segments. Based on the morphology of the sensilla in each sex, seven types of sensillum were identified: sensilla trichodea (Tr.1, Tr.2 and Tr.3), sensilla basiconica (Ba.1, Ba.2, and Ba.3), sensilla styloconica (St.1 and St.2), sensilla placodea, sensilla coeloconica, sensilla squamiforma, and Bohm’s bristles. Tr.2, Ba.1, and St.1 were only found in females, whereas Ba.2, Ba.3, and St.2 were only observed in males. Sensilla placodea were the most common, given that they occur on the antennae of many parasitoid Hymenoptera, whereas sensilla Tr were the most abundant, being distributed over the entire antennal surface. These sensilla are likely to have roles in the host locating and habitat searching behavior of adult Sclerodermus wasps. Therefore, our findings provide a basis for further studies of the host location behavior of this and other species of parasitic wasp.     

Changes in the surface morphology of starch granules of the cultivated potato,Solanum tuberosum L. during storage

Summary Low temperature sweetening is a major problem to chip and crisp manufacturers as it results in the production of unacceptably dark fry products. Cryo-electron microscopy was used to examine the changes which occur to the surface morphology of starch granules from tubers of cultivars Record and Brodick stored at 4°C and 10°C. At harvest, the surface of the starch granules was smooth but during storage the surface of the granules became progressívely more pitted. The feasibility of using this technique to determine whether increased starch breakdown occurs at low storage temperatures is discussed. Deceased.     

Reduction of Optimal Thermal Range in Aging Western Cherry Fruit Flies (Diptera: Tephritidae)

The western cherry fruit fly is an economically important pest of sweet cherries in the western United States. The potential of this pest to establish and spread in areas in which it is not currently present has been the focus of recent research. Most published information on the thermal tolerance and optimal thermal range of this pest has focused primarily on the diapausing pupae and predictive phenology models. Microrespirometry and differential calorimetry can be useful tools in describing the thermotolerance and optimal thermal range of insects. This methodology was employed to investigate the effects of western cherry fruit fly adult age on the optimal thermal range. Newly emerged flies exhibited the widest optimal thermal range spanning from 6.6 to 42.2°C for a total range of 35.8°C during heating scans of 0.4°C/min from 2 to 50°C. This range diminished as the flies aged, with the shortest span observed with 28-d-old flies ranging from 10.5 to 37.8°C, a span of 27.2°C. Measurements of heat rate and oxygen consumption at isothermal, or static, temperatures indicated that all flies could survive exposure to 40°C for at least 20 min, and that metabolism was greatly reduced, with a concomitant reduction in oxygen consumption rate at 40 to 42°C. All flies exhibited a heat rate and oxygen consumption rate of zero when exposed to 45 and 50°C. The loss of thermotolerance in adult flies can influence its ability to establish and spread in climates where daily temperatures exceed the optimal thermal range of this species.     

Effect of pre-cooking in potato granule production by a freeze-thaw process

Summary Steam-cooked potatoes pre-cooked for 20 min at 70 C were firmer than those cooked without pre-treatment. The product remained intact and required a greater force for subdivision into smaller aggregates. Excessive cell damage was sustained during the mashing step of the freeze-thaw (F-T) process, resulting in a gluey mash which could not be easily processed into granules. The pectic substances of the potatoes with pre-treatment were less solubilized than those cooked without. This suggested that they were made more resistant to thermal degradation by pre-cooking, resulting in greater intercellular cohesion and less rarefaction of the cell wall during subsequent cooking. Cell separation was poor in the following F-T process. Electron photomicrographs showed that precooking gelatinized the starch and that the cell wall remained unseparated.

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Zusammenfassung Ged?mpfte Kartoffeln, 20 Minuten bei 70±1 C vorbehandelt, wiesen eine festere Konsistenz auf als solche ohne Vorbehandlung (Tab. 2). Dieses Produkt blieb eher intakt und es erforderte mehr mechanische Arbeit, um es in kleinere Bruchstücke zu zerteilen, die eine Vorbedingung des Gefrier-Tau-Verfahrens (G-T-Verfahren) sind. Dies verursachte gr?ssere Sch?den, die zur Bildung eines klebrigen Breis führten (Tab. 3), der mit dem G-T-Verfahren nicht zu Granulat verarbeitet werden konnte. Trotz einiger ?nderungen des Verfahrens, z.B. l?ngeres Pürieren und tiefere Trocknungstemperatur, war die Ausbeute an Granulat gering und die Anzahl der verletzten Zellen hoch (Tab. 1). So behandelte Kartoffeln zeigten eine geringere L?slichkeit pektinartiger Verbindungen (672.2 mg Galakturonide pro 100 g Trockenmasse) als ged?mpfte Kartoffeln ohne Vorbehandlung (1106 mg/100 g Trockenmasse). Das D?mpfen allein schien alle pektinartigen Substanzen in L?sung zu bringen, w?hrend ein Drittel des Pektins ungel?st blieb, wenn die Kartoffeln vorbehandelt wurden (Tab. 4). Dies l?sst vermuten, dass durch die Vorbehandlung die pektinartigen Substanzen gegen weitere Hitzeeinflüsse resistent werden, was zu einer Verminderung des Verlustes des interzellul?ren Zusammenhaltes sowie einem verminderten dünner werden beim darauffolgenden D?mpfen führt. Deshalb war das Kartoffelgewebe fester als dasjenige, welches nicht vorbehandelt wurde. Elektronenmikroskopische Untersuchungen zeigten, dass das Vorkochen die St?rke gelatinisierte und die Zelle lose füllte, w?hrend die meisten Zellw?nde aneinander haften blieben (Abb. 2 und 3). Da die Bindungskr?fte zwischen den Zellen sogar nach dem D?mpfen gut erhalten blieben, war die Zellabspaltung im darauffolgenden G-T-Verfahren gering (Abb. 8–11).

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Résumé Les pommes de terre cuites à la vapeur après avoir subit une précuisson pendant 20 min à 70±I C sont plus fermes que celles obtenues sans précuisson (tableau 2). Un tel produit a tendance a rester intact et demande une plus grande action mécanique pour être reduit en particules plus petites lors de la mise en purée par la méthode requise lors du procédé ‘freezethaw’ (F-T). Ceci entraine des domages importants des cellules, rendant la purée collante et impropre à la granulation lors du procédé F.T. (tableau 3). Même par le biais de quelques modifications du procédé, e.g. un malaxage plus long de la purée et une température de séchage inférieure, le rendement en granules reste faible et le nombre de cellules broyées trés élevé (tableau 1). Les pommes de terre subissant ce traitement présentent une faible solubilisation des substances pectiques (673.2 mg d’uronide par 100 g de matière sèche) comparé aux pommes de terre cuites sans précuisson (1106 mg/100 g de matière sèche). La cuisson à la vapeur semble solubiliser à elle seule toutes les substances pectiques utilisables alors qu’un tiers de la pectine reste insolubilisée lorsque le produit a subit une précuisson (tableau 4). Ceci suggère que la précuisson rend les substances pectiques plus resistantes à toute dégradation thermique successive, diminuant la perte de liaisons entre les cellules et raréfiant la séparation des parois cellulaires lors de la cuisson. Donc, les tissus obtenus sont plus fermes que ceux qui n’ont pas re?u de prétraitement. Des photos au microscope électronique montrent que la précuisson gélatinise l’amidon qui remplit alors tout le volume cellulaire tandis que la plupart des parois cellulaires restent liées les unes aux autres (figures 2 et 3). Les forces de liaison entre cellules restant donc importantes même après cuisson à la vapeur, la séparation des cellules est mauvaise lors des étapes suivantes du procédé F-T (figures 8 à 11).

     

In vitro starch digestibility and predicted glycaemic indexes of buckwheat,oat, quinoa,sorghum, teff and commercial gluten-free bread

The in vitro starch digestibility of five gluten-free breads (from buckwheat, oat, quinoa, sorghum or teff flour) was analysed using a multi-enzyme dialysis system. Hydrolysis indexes (HI) and predicted glycaemic indexes (pGI) were calculated from the area under the curve (AUC; g RSR/100g TAC*min) of reducing sugars released (RSR), and related to that of white wheat bread. Total available carbohydrates (TAC; mg/4 g bread “as eaten”) were highest in sorghum (1634 mg) and oat bread (1384 mg). The AUC was highest for quinoa (3260 g RSR), followed by buckwheat (2377 g RSR) and teff bread (2026 g RSR). Quinoa bread showed highest predicted GI (95). GIs of buckwheat (GI 80), teff (74), sorghum (72) and oat (71) breads were significantly lower. Significantly higher gelatinization temperatures in teff (71 °C) and sorghum flour (69 °C) as determined by differential scanning calorimetry (DSC) correlated with lower pGIs (74 and 72). Larger granule diameters in oat (3–10 μm) and sorghum (6–18 μm) in comparison to quinoa (1.3 μm) and buckwheat flour (3–7 μm) as assessed with scanning electron microscopy resulted in lower specific surface area of starch granules. The data is in agreement with predictions that smaller starch granules result in a higher GI.     

Identification and Characterization of Reduced Epicuticular Wax Mutants in Rice

Epicuticular wax forms the outermost protective barrier of the aerial surfaces of land plants, working in concert with other components of the plant cuticle to prevent uncontrolled loss of water and to provide protection against an array of external environmental stress. In this study, chemicallymutagenized populations of rice(Oryza sativa L.) derived from approximately 4 750 M2 families were screened for adhesion of water droplets resulting in a wet leaf/glossy(wlg) phenotype. Mutants were identified in 11 independently-derived M2 families. Scanning electron microscopy analysis confirmed the association of the wlg phenotype with changes in the epicuticular wax crystals of these plants. The phenotypes of five mutants(7-17 A, 26.1, 524.2, 680.2, and 843.1) were confirmed to be the result of single recessive gene mutation. Evaluation of mutants from 3(6-1A, 7-17 A, and 11-39A) of 11 M2 families revealed significant reductions( 50%) in surface wax content and increases in cuticle membrane permeability.     

杂交早稻亲本遗传差异及其与杂种优势的关系

以４个不育系、７个恢复系及其配制的２８个杂交早稻组合为材料,根据８个农艺性状进行主成分和聚类分析,研究了杂交早稻亲本间的遗传差异状况及其与杂种优势的关系。结果表明,１１个亲本间的平均遗传距离为５．９２６８,最大为１９．２５２７,最小为０．３４８９;不育系内和恢复系内各亲本之间存在一定的遗传差异,且保持系内的遗传差异显著大于恢复系内的遗传差异,但两者与保持系与恢复系间的遗传差异没有明显的不同。相关分析表明,亲本间的遗传距离与杂种优势及杂种产量关系不密切。     

Effect of endosperm starch granule size distribution on milling yield in hard wheat

Increased flour yield in hard wheat is associated with increased endosperm rheology index, calculated from strength and stiffness as measured by the SKCS. A study of the fractured endosperm of hard wheat varieties grouped according to similar rheology index values was performed using environmental scanning electron microscopy (ESEM). Differing microstructures and fracture patterns were observed between each group. Specifically, the group representing high rheology index had a greater concentration of small starch granules in prismatic cells. Samples of diverse wheat germplasm were grown at two sites and subjected to laboratory milling. Starch granule size distribution (SGSD) analysis using a laser diffraction method was undertaken on a subset of samples in triplicate representing a range in flour yield. The results supported an hypothesis for a significant influence of SGSD on flour yield of hard wheat varieties. In addition, a significant part (R²>0.40 (p<0.05) at two sites) of the association appeared to be under genetic control. Results indicate a more even gradation of distributions involving an increase in the sample volume % of small granule (types B and C) and decrease in type A granules. This was associated with increased rheology index values and higher flour yield. The ratio of type A:C starch granules accounted for up to 58% (p<0.05) of the variation in flour yield in the samples studied. Thus, rheological parameters measured using a rapid SKCS screening method can be linked to the genetic regulation of SGSD with implications for the improvement of commercial processing performance of hard wheat.     

同源四倍体水稻雌雄配子体多态性的研究

同源四倍体水稻（２ｎ＝４ｘ＝４８）由于其细胞内染色体数的倍增而导致其生殖性状发生了明显的变化。在其雄配子体中存在着比较少的正常花粉粒（１３．３５％￣１７．４９％）和比较多的败育花粉粒（８２．５１％￣８６．６５％）。在败育花粉粒中包括典败,园败和染败花粉粒。在同源四倍体水稻ＡＰＩＶ的成熟胚囊内存在着正常蓼型胚囊（４３．０％）,退化型胚囊（３６．０％）和变异型胚囊（２１．０％）,在变异型胚囊中包括双卵     

采后枇杷果皮细胞壁代谢和果实超微结构与贮藏性的关系

研究‘早钟6号’枇杷果实裸藏和聚乙烯薄膜袋藏下果皮的细胞壁代谢。结果表明:裸藏与袋藏的‘早钟6号’枇杷果实采后8℃下贮藏期间,果实失重率不断增大,果皮细胞膜相对渗透率、果胶酯酶(PE)和多聚半乳糖醛酸酶(PG)活性逐渐升高;果皮细胞膜相对渗透率与PE、PG活性呈显著正相关效应(p0.01);但袋藏可极显著(p0.01)地减少果实失重率,延缓果皮的细胞膜相对渗透率、PE和PG活性升高,说明薄膜包装贮藏能抑制果实失水、降低细胞壁降解酶(PE、PG)活性和维持果皮细胞膜的完整性。进一步通过扫描电镜观察比较了不同贮藏性的5个枇杷品种果实的超微结构,结果表明:枇杷果皮多皮孔,果顶与果蒂部位绒毛少且稀疏,果肉肉质细、具有大的细胞间隙和胞间腔,这些超微结构易引起采后枇杷果实失水和病原微生物侵染,从而导致果实贮藏性和抗病性下降。     

同源四倍体水稻胚乳发育:极核融合和胚乳细胞化

利用激光扫描共聚焦显微术和塑料包埋半薄切片技术观察同源四倍体水稻极核融合及游离核进一步发育的过程,发现同源四倍体水稻约有1/3子房极核融合过程和游离核进一步发育与其二倍体原种的基本一致;2/3子房出现各种异常现象,如极核未受精、受精异常和胚乳游离核发育滞后等。应用荧光增白剂染色对胚乳细胞化过程进行观察,直接观察到胚乳初生壁的出现和形成过程以及不同部位的胚乳细胞壁的形成机理。表明同源四倍体水稻与二倍体水稻胚乳的细胞化过程基本一致,胚乳细胞初始垂周壁来源于珠孔端胚囊壁内突向心游离生长,初始平周壁来源于游离核有丝分裂产生的成膜体,而中间胚乳细胞壁则有些来源于游离核有丝分裂产生的成膜体,有些是自由生长而来。同源四倍体水稻胚乳细胞化过程也出现相当比例的异常现象,如无细胞壁形成、细胞化不同步和产生分枝状的细胞壁等。同源四倍体水稻胚乳发育过程中出现的极核融合、游离核发育和细胞化过程等异常都可能导致同源四倍体水稻的结实率降低。     

甜菜细胞质雄性不育与花蕾细胞分裂素含量的关系

以两对甜菜细胞质雄性不育系及其相应保持系为材料,利用间接酶联免疫(ELISA)检测技术,对生殖生长阶段花蕾组织中的细胞分裂素含量进行了研究。结果表明:在甜菜生殖生长阶段,花蕾中DHZR、IPA的含量表现为保持系高于其同型不育系,ZR的含量表现为不育系高于其保持系,两对不育系和保持系表现了相同的规律,因此可以认为细胞分裂素含量的变化与甜菜雄性不育的发生有一定的关系。     

Role of Genes in Regulating Host Plants Expansion in Tephritid Fruit Flies (Diptera) and Potential for RNAi-Based Control

Host plant expansion is an important survival strategy for tephritids as they expand their range. Successful host expansion requires tephritids to adapt to the chemical and nonchemical properties of a novel host fruit, such as fruit color, phenology, and phytochemicals. These plant properties trigger a series of processes in tephritids, with each process having its own genetic basis, which means that various genes are involved in regulating host plant expansion by tephritids. This review summarizes current knowledge on the categories and roles of genes involved in host plant expansion in several important tephritid species, including genes related to chemoreception (olfactory and gustation), vision, digestion, detoxification, development, ribosomal and energy metabolism. Chemoreception- and detoxification- and digestion-related genes are stimulated by volatile chemicals and secondary chemicals of different hosts, respectively, which are involved in the regulation of nervous signal transduction that triggers behavioral, physical, and chemical responses to the novel host fruit. Vision-, nerve-, and development-related genes and metabolism-associated genes are activated in response to nonchemical stimuli from different hosts, such as color and phenology, to regulate a comprehensive adaptation of the extending host for tephritids. The chemical and nonchemical signals of hosts activate ribosomal and energy-related genes that result in the basic regulation of many processes of host expansion, including detoxification and development. These genes do not regulate novel host use individually, but multiple genes regulate multilevel adaptation to novel host fruits via multiple mechanisms. These genes may also be potential target genes for RNAi-based control of tephritid pests.     

Nutritional properties and ultra-structure of commercial gluten free flours from different botanical sources compared to wheat flours

Coeliac patients suffer from an immune mediated disease, triggered by the ingestion of a protein composite (gluten) found in wheat, rye and barley. Consequently, there is a need for products such as bread or pasta, made from alternative cereal grains or pseudocereals. A fair proportion of the gluten free products currently on the market are nutritionally inadequate. Hence, it was the aim of this study to investigate the nutrient composition of seven commonly used commercial gluten free flours (oat, rice, sorghum, maize, teff, buckwheat and quinoa) and compare them to wheat and wholemeal wheat flour. In addition to the levels of all major compounds, also mineral composition, fatty acid profile, phytate, polyphenols and folate content were determined. Furthermore, properties of carbohydrates were studied in greater detail, looking at total and damaged starch levels; total, soluble and insoluble dietary fibre content as well as amylose/amylopectin ratio. Proteins were further investigated by means of capillary electrophoreses. Additionally, the ultra-structure of these materials was explored using scanning electron microscopy. The results show that maize and rice flour are poor regarding their nutritional value (low protein, fibre, folate contents). In contrast, teff as well as the pseudocereals quinoa and buckwheat show a favourable fatty acid composition and are high in protein and folate. In particular, quinoa and teff are characterised by high fibre content and are high in calcium, magnesium and iron. Therefore these flours represent nutrient-dense raw materials for the production of gluten free foods.     

Regional susceptibility to domoic acid in primary astrocyte cells cultured from the brain stem and hippocampus

Domoic acid is a marine biotoxin associated with harmful algal blooms and is the causative agent of amnesic shellfish poisoning in marine animals and humans. It is also an excitatory amino acid analog to glutamate and kainic acid which acts through glutamate receptors eliciting a very rapid and potent neurotoxic response. The hippocampus, among other brain regions, has been identified as a specific target site having high sensitivity to DOM toxicity. Histopathology evidence indicates that in addition to neurons, the astrocytes were also injured. Electron microscopy data reported in this study further supports the light microscopy findings. Furthermore, the effect of DOM was confirmed by culturing primary astrocytes from the hippocampus and the brain stem and subsequently exposing them to domoic acid. The RNA was extracted and used for biomarker analysis. The biomarker analysis was done for the early response genes including c-fos, c-jun, c-myc, Hsp-72; specific marker for the astrocytes- GFAP and the glutamate receptors including GluR 2, NMDAR 1, NMDAR 2A and B. Although, the astrocyte-GFAP and c-fos were not affected, c-jun and GluR 2 were down-regulated. The microarray analysis revealed that the chemokines / cytokines, tyrosine kinases (Trk), and apoptotic genes were altered. The chemokines that were up-regulated included - IL1-alpha, IL-Beta, IL-6, the small inducible cytokine, interferon protein 10P-10, CXC chemokine LIX, and IGF binding proteins. The Bax, Bcl-2, Trk A and Trk B were all down-regulated. Interestingly, only the hippocampal astrocytes were affected. Our findings suggest that astrocytes may present a possible target for pharmacological interventions for the prevention and treatment of amnesic shellfish poisoning and for other brain pathologies involving excitotoxicity.     

橡胶种子呼吸的电子传递途径和种子活力的关系

研究结果表明,（１）用ＳＨＡＭ（水杨肟酸）处理种子,能部分抑制抗氰电子传递途径,种子活力指数也随之大幅度下降,主要表现为“苗”生长受到抑制,同时贮藏脂质的降解及糖再生的乙醛酸环代谢速率也大幅度下降;（２）用ＮａＣＮ处理种子,提高了抗氰呼吸电子传递途径比率,但并未提高种子的活力指数,种子活力指数反而稍有下降;（３）ＳＨＡＭ和ＮａＣＮ的预处理,对种子的发芽率没有明显影响。     

甜菜细胞质雄性不育系与其保持系游离脯氨酸含量的差异

以甜菜3个细胞质雄性不育系及其相应保持系为材料,对营养生长阶段叶片中的脯氨酸含量进行了研究.结果表明:在甜菜营养生长阶段的4个时期中,脯氨酸含量基本表现为保持系高于不育系.说明不育系和保持系在营养生长阶段生理生化代谢上已经存在差异.