1,721,067 research outputs found
Development of Mass Production of VAMF Inoculum by Sand Culture
No full text內生菌根菌(Vesicular-aibuscular mycorrhizal fungus, VAMF)證實與許多作物根系具有親和主，當VAMF感染作物根部形成內生菌根時，往往能產生有益效應，促進根群發育，增加根部對磷肥等要素之吸收能力，促進植株生長。惟內生菌根菌是一種活物寄生真菌，目前尚無法在文工培養基上大量繁殖，接種盆栽宿主植物繁殖內生菌根菌接種源是目前唯一可行途徑。除宿E外，土壤（栽培介質）因子、環境因子等亦可影響內生菌根菌之繁殖。本分所建立之內生菌根百接種源生產體系，分為三個步驟：（一）以多年生百喜草盆栽保存純種，（二）以盆栽玉米繁殖貝種，（三）以大型栽培床之玉米（或營多藤）大量繁殖內生菌根菌，經收集培養土（含宿主根長）風乾裝袋而成接種源。在實際應用上，採用苗期接種，培養洋香瓜內生菌根苗，當內生菌根苗移植於本田，即可將菌種帶到田間，發揮內生菌根之功能，表現其有益效應。
The vesicular-arbuscular mycorrhizal fungus was proved to have the compatibility with root systems of many crops. Formation of VA mycorrhiza in root systems of crops infected by VAM fungus could arise beneficial effects, i.e. promoted the growth and development of root systems, increased the absorption of soil mineral elements, enhanced the top growth of crops. Up today, the common method for propagation of VA mycorrhizal fungi were pot culture because they were obligate symbionts. Factors affected the propagation of VA mycorrhizal fungi in pot culture included host plants, soil (culture media), and environment. We developed a procedure for propagation of VAM fungus inoculum as follows: 1. maintaining the pure VA mycorrhizal fungus in pot culture of bahiagrass, 2. propagation of VAM fungus in pot culture of corn, 3. mass production of VA mycorrhizal fungus inoculum in sand bed culture of corn or beggarhce, 4. air-drying and bagging the harvested culture soil including the segments of infected root systems of host plants and fungal chiamydospores. Method for application of VA mycorrhizal fungus to field was by transplanting mycorrhizal seedlings of muskmelon pre-inoculated with infested soil in plastic net house. When the mycorrhizal seedlings were transplanted to the field, mycorrhizal root systems could show beneficial effects to muskmelon production
(25(2):134-140)STUDIES ON SEED TRANSMISSION OF FLAX FUSARIUM WILT AND ITS CONTROL WITH SEED TREATMENT
No full text亞麻立枯病病原菌雖係土壤傳播真菌，但也可經由種子而萬播。採收自罹病亞麻田之種子質輕、不飽滿而略扁平、表面有皺紋、無光澤、千粒重為2.3~3.0g，依發病程度而異；反之健全田之種子較重、飽滿、黑褐色、表面平滑、有光澤、千粒重為3.6g。種子攜帶病原菌之比率為0.42~6.00%，與田間亞麻罹病率成正相關。病原菌亦可侵入種皮內，其比率為0.02~0.1%。以發病亞麻田（發病率26~50%）採收之種子播種會引起萌前腐敗，亦可導致發生幼苗立枯病，前者達15.7%，後者為7.6%。
亞麻種子以50% Benlate W. P., Benlate T-20, 50%Vitavax-Thi-ram W. P., 50% Bavistin W. P.等0.5~0.1%（依重量計算）行拌種處理，可有效防止病原菌之蔓延，但因亞麻種子表面有膠質，遇水黏結成團，處理工作不易進行。故採用Dowfumo MC-2 1.5 lbs/22.32m3行燻蒸處理，為既有效又經濟之方法。
Although flax wilt pathogen, Fusarium oxysporum f. sp. lini, is a well known soil-borne fungus, it can also be transmitted by seeds. Seeds harvested from diseased flax fields are lighter, yellowish to dark brown, rough and dull, weight per thousand seeds varied from 2.3 to 3.0 g depending upon the percentage of wilt flax in the field. On the other hand, seeds from healthy flax fields are heavier, dark brown, smooth and shining, weight per thousand seeds is 3.6 g. Seeds from diseased fields carried F. oxysporum f. sp. lini with the rates varied from 0.42 to 6.00%, proportioned with the severity of flax wilt. However, wilt pathogen was detected not only on the seed but also in the seed. There were 0.02-0.10% of seeds found to carry the pathogen inside the seedcoat. Sowing of seeds from moderately diseased field (26-50% of flax wilt) resulted 15.7% of preemergence rot and 7.6% of seedling wilt.
Slurry-overcoating of flax seeds with Benlate, Benlate T-20, Vitavax-Thiram, or Bavistin at the rate of 0.5-1.0% by weight was effective in controlling seedling wilt and increasing stands. However, because of flax seeds are covered with a layer of gelatinous substance and are adhering in mass when wet, slurry-overcoating is not a good method for flax seed treatment. Fumigation with Dowfume MC-2 at the rate of 1.5 lbs/22.32 cu m for 14 hr during the storage period in a compact warehouse is recommended
(29(1):47-53)Identification of Meloidogyne arenaria on peanut in Taiwan
No full text落花生根瘤線蟲病近年來在雲林地區逐漸成為重要之花生病害。其病原線蟲經鑑定為Meloidogyne arenaria ( Neal , 1889 ) Chitwocd , 1949。其成熟雌蟲之陰門模紋型（Perineal pattern）通常為卵圓型，但其長軸卻與側線（Lateral line）平行。特徵為拱弧（Arch）較低而圓，由平整條紋（Smooth striae）所構成，背部及腹部條紋（Dorsd and ventral striae）在側線處成角度之相會，側線處有許多雜亂之短條紋，肛門上方無點狀物（Punctation）。雌蟲排泄孔（Excretory pore）約位於頭端後方2 倍口針長之處。本線蟲二齡幼蟲體長1.440 mm 二－( 0.37 ～• 0.49 mm）。侵染落花生後，引起植株矮小、黃化及提早落葉等病徵。根部被感染則產生類似串珠狀之根瘤，但不像M . hapla 會自根瘤處再生放射狀之側根。豆莢及莢柄被侵害，則引起腫狀瘤而畸型。M. arenaria 對蕃茄（盛岡7 號）及小鳳西瓜也有病原性，會引起腫瘤，但對棉花（Stoneville 7A）則無病原性。
Peanut root-root-knot nematode disease has become an important and has threated to peanut production in Yien-lin growth area recently. The causal agent was identified as Meloidogyne arenaria (Neal, 1889) Chitwood, 1949. Perineal pattern of M. arenaria shows oval-shaped with longer axis in the lateral direction. Arch rounded to low is composed of smooth striae. There are numerous short disordered striae in the lateral fields where dorsal and ventral striae meet at an angle. Perineal pattern of this species is never found punctation above the anus. Female excretory pore is at about 2 stylet lengths posterior to apex of head. Median length of larvae of this species is 0.440 mm (0.37-0.49 mm).
The 2nd stage larvae infect peanut, causing stunting, yellowing, and early falling of leaves. Root systems invaded by this spicies cause root knots in chains, but rarely have lateral rootlets grown directly from gall as those caused by M. hapla. Shells and stems infected by M. arenaria cause galls and become malformed. M. arenaria also causes galls and reproduces on tomato (Sheng-kang No. 7) and watermelon (Honty baby), but not on cotton (Stoneville 7A)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
(28(2):91-99)Pathogenesis of Meloidogne incognita to edible ginger
No full text根瘤線蟲（Meloidogyne incognita）侵入薑塊莖後不形成明顯之腫瘤。第2 齡幼蟲自塊莖鱗片狀葉著生處內側侵入，使鄰近之細胞產生褐色壞疽，降低生薑之市場價值。第2 齡幼蟲也從根冠附近侵入根系（鬚根及肉質根），遂移動到維管束附近攝食，生長並剌激形成不正常組織，包括細胞增生及巨型細胞等，產生肉眼可視別之腫狀根瘤。在30℃土壤溫度下，該線蟲在薑根系完成一世代須21 天，但在塊莖則要40 天。侵染根系之雌蟲成熟後釋放卵塊到根部外面，為塊莖及根系的第二次侵染源。塊莖內之成熟雌蟲僅能在塊莖內部維管束附近生產卵塊，而未釋至土內，致使大部份孵化之2 齡幼蟲侷限在病患處。
The second-stage larvae of Meloidogyne incognita enter the ginger rhizome through the axil of leaf sheath at the shoot apex, resulting the appearance of extensive internal lesions. No visible galls are formed on the infected rhizome throughout the entire period of pathogenesis. The lervae infect root system, including fibrous and fleshy roots, at the root-tip rigions. They penetrate through epidermis and cortex, and aggregate at vascular tissues (stele). As the results of nematode feeding, histological changes, such as formation of giant cells, hyperplastic parenchyma and abnormal xylem, are stimulated. Subsequently, externally visible galls are formed.
The nematode takes 21 days to complete the life cycle in fibrous and fleshy roots, but requires 40 days in rhizomes at 30°C soil temperature. Mature females release egg masses into the soil from diseased fibrous roots to serve as the main source of secondary inoculum. On the other hand, the mature females in diseased rhizome lay egg masses only in the diseased tissues, and thus, the second-stage larvae are limited in there
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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