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(31(2):144-154)Factors Influencing the Development of Peanut Crown Rot Caused by Aspergillus niger and the Measures for Disease Management
No full text本研究測定影響落花生冠腐病發病之因子，並發展有效之防治方法。花生收穫剝殼時，花生仁表面污染Aspergillus niger，帶菌率可達100%，但為無效感染源。經過一年以上之儲存，部份污染外表之病菌，可感染種子胚部之子葉及胚軸，成為重要接種源，引起幼苗期病害，且無法以溫水浸種方法除去。土壤顆粒之A. nige含量（propagules/g soil）與發病無關，接種源需要營養基（food base）增加接種源潛勢（inoculum potential），才能引發病害。田間試驗顯示，以菌絲塊、小麥接種源或混雜玉米桿於田土等方法行接種試驗，在有傷口及乾旱的條件下，皆可引發病害，然而在花生播種後21 天內維持田間灌水，使土壤達田問含水量之溼度（-1 / 3 bars 左右），即可防治本病害。灌水措施可提高土壤及植物各部之水潛勢，而乾燥處理之土壤，導管及莖冠部組織之水潛勢，分別為-6.4、-3.1及-8.41 bars，而灌水措施者，則分別為-0.5、-0.7及-5.8 bars。
Factors influencing the development of peanut crown rot was investigated and the control measures were developed and recommended. During hand-shelling, surface of almost all peanut kernels might be contaminated with Aspergillus niger which was, however, a nonfunctional inoculum under this condition. When the contaminated seeds were stored for more than one year. A. niger might penetrate the seed coat (testa) and infect the cotylendons and embryonic axis, and became the important inoculum of crown rot in peanut seedlings. The inoculum could not be eliminated by seed treatment with hot water at temperatures up to 60°C without damaging seed germination. The density of A. niger in soil particles (propagules/g) had no effect on the occurrence of the disease. A. niger needed food base to increase the inoculum potential to cause crown rot of peanut. Field inoculation experiments showed that peanut plants might be killed by using mycelium mat, wheat inoculum or corn stalk as inoculum under dry condition (water stress) with wounded crown. However, irrigation of peanut field to maintain moisture at field capacity (-1/3 bars) within 21 days after planting could protect the plants from severe damage caused by A. niger. The water potentials of soil, xylem and crown tissue were -6.4, -3.1 and -8.4 bars in dry plots, and -0.5, -0.7 and -5.8 bars in irrigated plots, respectively
(37(3):305-312)White Root Rot of Loquat and Its Pathogen
No full text枇杷白紋羽病於民國七十四年首自卓蘭發現。罹病枇杷的根部密生白色菌絲，致使葉片逐漸黃化、萎凋，最後植株死亡。病原菌經分離及鑑定後，證實為Rosellinia ( Demato - phora ) recatrix。將本菌菌絲培養於麥粒，接種在盆栽枇杷苗的根部，約經60天，可產生與田間病株相同的病徵。病原菌的子囊殼及分生孢子並未於田間發現。但將田間罹病的枇杷根置於室內黑暗且潮濕的環境下，可誘導其產生大量的子囊殼及分生孢子。分生孢子在本研究中未見其發芽，但單一子囊殼自動釋放之子囊孢子於2％水瓊脂上，却有0～35％的發芽率。本菌最適生長溫度為20～28°C，最適生長水分潛勢為0～－10bars。溫度在8°C以下，32°C以上或水分潛勢在－54bars 以下，本菌之生長完全受到抑制。
White root rot of loquat caused by Rosellinia (Dematophora) necatrix was first found in Cholan, Taiwan in 1985. The infected plants appeared leaf yellowing in the beginning and ended up wilt of the trees. Symptoms were reproduced in the greenhouse witihin 60~80 days after inoculation of the loquat plantlets with R. necatrix. The conidia and perithecia of the pathogen were not observed in the field, but, they were induced on the infected roots after they were incubated in a moist chamber under shade for months. The conidia did not germinate on water agar and potato dextrose agar. The ascospores discharged on water agar from each perithecium had 0~35% germination rate. Optimum temperature and osmotic water potential for fungal growth in vitro were 20~28 C and 0~－10 bars, respectively. Temperature below 8 C or above 32 C or osmotic water potential below －54 bars completely inhibited the fungal growth
Phytophthora melonis在水田裡之生態及防治
No full text胡瓜疫病菌(Phytophthora melonis)之游走子囊在病組織上不具脫落性，乾風無法將之吹落。但是它的游走子及游走子囊可隨灌溉水及飛濺的雨水傳播。土壤濕度強烈影響病原菌的存活，病原菌在淹水的土壤中僅能存活4星期，但在含本量6%及20%，稍可通氣之濕土裡，也僅能存活5~20星期。田間試驗顯示，在經過兩期水稻輪作的病圃裡，胡瓜疫病菌不能存活。而引起胡瓜疫病之病原菌初次感染源，並非來自土壤或種子，而是來自隣田的灌溉水。在田間，殺菌劑(Ridomil. MZ)和土壤添加物（雞糞和S-H混合物）配合使用對胡瓜疫病之防治效果最顯著。該二種土壤添加物可提升土壤的pH值，但土壤pH值的變化與病害防治無關。雞糞和S-H混台物僅有促進植株生長勢的效果。在試驗中Ridomil MZ殺菌劑才是抑病的主要因素。
Dry air current failed to remove the sporangia of Phytophthora melonis from the disease lesions. However, the fungus was easily dispersed by its zoospores and sporangia carried in irrigation water or liberated to the air by wind-blown rainsplashes. The soil moisture strongly influenced the survival of P. melonis. The fungus persisted only for 4 wks in flooded soil, while in soil with moisture content at 6 % or 20%, a condition that permitted soil aeration, the fungus could be detected from the infested soil for a period of 5~20 wks. Field experiments demonstrated that P. melonis did not survive, nor did it induce cucumber blight in a disease nursery after two successive crops of rice plants. The primary inoculum of P. melonis to cause cucumber blight in the drained paddy fields did not come from the paddy soil nor from cucumber seeds. It was mainly from irrigation water from neighbor fields. Cucumber blight was best controlled by using combinations of fungicide Ridomil MZ and soil amendments, i. e. chicken manure or S-H mixture. The soil amendments raised soil pH to alkaline range for 7 days, then it fell to the acid range again. The changing pattern of soil pH had no correspondence to the inhibition of cucumber blight. Both chicken manure and S-H mixture had nutrient effects to result in improved plant growth. However, Ridomil MZ was the main factor that inhibited disease development in our experiments
S-H混合物防治胡瓜猝倒及根腐病
No full textS-H mixture used as soil amendment at the rates of 0.5 to 2% (w/w) greatly or completely inhibited damping off and root rot of cucumber caused by Pythium aphanidermatum under the greenhouse and field conditions. Among the various combinations of the components of S-H mixture tested in laboratory, urea was the main factor for the inhibition of oospore survival and mycelial growth of the pathogen. Siliceous slag had some additive effect. Urea alone was almost as effective as S-H mixture in reducing the pathogen population and suppressing the disease, but the gained suppressiveness was lost after 25 days of incubation. Soil amended with urea plus siliceous slag remained suppressive at least for 28 days, the longest incubation period conducted in this study.
在溫室及田間的條件下，使用0.5~2%(w/w)的S-H混合物為土壤添加物，能夠大量或完全抑制由Pythium aphannidematum引起的胡瓜猝倒及根腐病。在實驗室測試S-H混合物各種成分之抑制效果，發現尿素是抑制病原菌卵孢子存活及菌絲生長之主要物質，而矽酸爐渣則有附加作用。單獨使用尿素和使用S-H混合物之效果相同，但只能維持25天，而將尿素和矽酸爐渣混合使用，其效果則至少可維持28天
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“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
Get PDFWe 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
Factors Affecting Ascospore Germination of Monosporascus cannonballus and Investigation of Ascospore Densities in Field Soils
No full text本論文主要目的在探討影響Monosporascus cannonballus子囊孢子發芽的因子，和利用蔗糖溶液循環沈澱法進行田間土壤中子囊孢子密度的偵測。利用土壤試管法種植洋香瓜，12天後可觀察到子囊孢子在根圈土壤中發芽並侵入根表，在24℃的環境下發芽率可達54.8%，但若將土壤經高溫高壓滅菌後，則子囊孢子不發芽；添加多種藥劑或抗生素於土壤中進行試驗，發現多數能抑制細菌或放線菌生長者也能夠抑制或降低子囊孢子發芽。進一步自不同來源之土壤中分離得到真菌、細菌與放線菌等三群微生物來進行土壤試管法之試驗，結果發現在滅菌土中僅加入放線菌之處理能大量促進子囊孢子發芽。為了求得更精確的發芽率，並方便研究其影響因子，本實驗室研發包埋子囊孢子試管法，使得子囊孢子能夠在培養基上發芽。應用本方法在處理後第27天之觀察結果發現，子囊孢子在距離根表0-2mm範圍內才能大量發芽，且多集中在0-1mm內，超過3mm距離者則甚少發芽。而且無論添加耕作田土或非耕作田土，甚至是加入泥炭土與魚缸底砂的處理，子囊孢子均有發芽的表現，但在加入珍珠石取代覆蓋土壤之處理或利用珍珠石添加土壤抽出液替代覆蓋土壤的處理中，發現子囊孢子仍不發芽。另外，在不種植洋香瓜的狀況下，改以洋香瓜根的萃取液加入越瓜田土中進行試驗，子囊孢子同樣無法發芽。選取在土壤試管法中較能有效促進子囊孢子發芽的四個放線菌菌株，A17、A21、A22與A33，並改以包埋子囊孢子試管法進行試驗；結果發現將放線菌加入滅菌土中確實能觀察到子囊孢子大量發芽，但在珍珠石中或是沒有土壤的環境下放線菌則沒有促進子囊孢子發芽的效果。本論文亦以蔗糖溶液循環沈澱法進行田間土壤中病原菌密度的調查，發現除了子囊孢子之外，偶爾也可偵測得到子囊殼的存在。在東山鄉與芳苑鄉的試驗田表土（0-10cm）中，子囊孢子密度平均各為9.9與9.8個/克土壤；東山試驗田經一期的水稻輪作後，密度降至1.28個/克土壤。在垂直分佈上，於東山試驗田測得子囊孢子多分佈在0-30cm深的土壤中，並有愈往下子囊孢子密度愈低的趨勢；而在30-50cm深的土壤中則較少見到游離的子囊孢子，但可觀察到少數未釋放的子囊殼存在。除罹病田外，在清泉岡蘿蔔田、大里竹子田等非發病田仍能測得子囊孢子密度各為5.6與1.8個/克土壤；甚至於中興大學之中興湖、小禮堂旁與花蓮秀姑巒溪旁的非耕作田土也各有0.5、0.1及0.2個子囊孢子/克土壤的存在。The main purpose of this thesis was to investigate the factors affecting the ascospore germination of Monosporascus cannonballus and to determine the ascospore densities in field soils by using circular sucrose and sedimentation tank method (CSSTM). Soil tube observation method (STOM) was employed to observe ascospore germination in rhizosphere soil and penetration into the root surface of muskmelon. Ascospore germination could reach 54.8% at 24℃, but ascospores did not germinate in the autoclaved soil. Several fungicides and antibiotics were used to treat the natural soil and the result showed that most of the tested chemicals could inhibit or reduce the ascospore germination. Several isolates of fungi, bacteria and actinomycetes isolated from different natural soils were added to the autoclaved soil and found that most tested actinomycete isolates could greatly increase ascospore germination. Using immersed ascospore tube method (IATM) to study the factors affecting the ascospore germination on agar medium, it was found that ascospores germinated at the distance of 0-2mm, especially greatly at 0-1mm, from the root surface, but rarely germinated beyond 3mm when the natural soils collected from crop fields were used as cover soil. Moreover, soils from non-crop fields, peat moss, and fish-jar sand also could stimulate ascospore germination but perlite (only 2.4%). By using IATM, when soil extract was added to perlite or muskmelon root extract was used instead of planting a muskmelon seedling, ascospores did not germinate, either. Four actinomycete isolates, A17, A21, A22 and A33, which could stimulate ascospore germination greatly by using STOM, were tested again for their abilities to stimulate the ascospore germination by operating IATM. They indeed greatly stimulated ascospore germination when autoclaved soil was used as cover soil. However, no ascospore germination was observed when their spore suspensions were added to the medium with no cover soil or with perlite as cover soil by using IATM. By using CSSTM, both ascospores and perithecia could be detected from the field soils and the ascospore densities of Monosporascus cannonballus in the top soils (depth of 0-10 cm) collected from Dongshan and Fangyuan muskmelon fields were 9.9 and 9.8 ascospores/g soil, respectively. The ascospore densities in Dongshan soil samples reduced to 1.28 from 10.4 ascospores/g soil after rotation with rice paddy once. Vertical distribution of the ascospores at Dongshan muskmelon field was also determined. It revealed that most wild ascospores existed within 30cm of soil depth and the deeper the lower ascospore numbers were detected. Few wild ascospores were detected within 30-50cm of soil depth, but sometimes intact perithecia could be observed. A carrot field at Chingchuankang and a bamboo field at Dalih were also subjected to determine their ascospore densities and yielded 5.6 and 1.8 ascospores/g soil, respectively. Furthermore, even in the soil samples collected from non-cropped fields, such as Chung Hsing Lake and Small Hall of National Chung Hsing University and Shougunuan River, the ascospore densities were 0.5, 0.1 and 0.2 ascospores/g soil, respectively.目錄
誌謝 -----------------------------------------------------------------------------------------------I
中文摘要 -----------------------------------------------------------------------------------------II
英文摘要 -----------------------------------------------------------------------------------------IV
目錄 -----------------------------------------------------------------------------------------------VI
附表目錄 -----------------------------------------------------------------------------------------IX
附圖目錄 -----------------------------------------------------------------------------------------XI
前言 -----------------------------------------------------------------------------------------------1
前人研究 -----------------------------------------------------------------------------------------2
材料與方法 --------------------------------------------------------------------------------------10
一、洋香瓜黑點根腐病菌菌株之來源與培養 --------------------------------------10
1. 供試病原菌菌株之來源 -----------------------------------------------------------10
2. 病原菌之保存與更新 --------------------------------------------------------------10
二、供試植物、土壤來源與土壤質地測定 -----------------------------------------10
三、洋香瓜黑點根腐病菌生長測試 --------------------------------------------------11
1. 溫度對菌絲生長的影響-------------------------------------------------------------11
2. 培養基對子囊殼形成的影響 -----------------------------------------------------11
3. 溫度對子囊殼形成的影響 --------------------------------------------------------12
4. 光照對子囊殼形成的影響 --------------------------------------------------------12
四、影響洋香瓜黑點根腐病菌子囊孢子發芽之因子 -----------------------------13
1. 利用土壤試管法觀察子囊孢子發芽----------------------------------------------13
2. 溫度對子囊孢子發芽的影響 -----------------------------------------------------14
3. 滅菌土壤對子囊孢子發芽的影響 -----------------------------------------------14
a. 高溫高壓滅菌土對子囊孢子發芽的影響 -----------------------------------14
b. 藥劑滅菌土對子囊孢子發芽的影響 -----------------------------------------14
4. 土壤微生物群對子囊孢子發芽的影響-------------------------------------------15
5. 利用包埋子囊孢子試管法觀察子囊孢子之發芽 -----------------------------16
6. 耕作田土壤與非耕作田土壤對子囊孢子發芽的影響 -----------------------16
7. 非土壤介質對子囊孢子發芽的影響 --------------------------------------------17
8. 土壤抽出液對子囊孢子發芽的影響 --------------------------------------------17
9. 植物根的萃取液對子囊孢子發芽的影響 --------------------------------------17
10. 放線菌對子囊孢子發芽的影響 -------------------------------------------------18
五、田間洋香瓜黑點根腐病菌子囊孢子密度調查 --------------------------------18
1. 土壤採樣 -----------------------------------------------------------------------------18
2. 蔗糖溶液循環沉澱法 --------------------------------------------------------------19
結果 -----------------------------------------------------------------------------------------------20
一、洋香瓜黑點根腐病菌生長測試 --------------------------------------------------20
1. 溫度對菌絲生長的影響 -----------------------------------------------------------20
2. 培養基對子囊殼形成的影響 -----------------------------------------------------20
3. 溫度對子囊殼形成的影響 --------------------------------------------------------20
4. 光照對子囊殼形成的影響 --------------------------------------------------------21
二、影響黑點根腐病菌子囊孢子發芽之因子 --------------------------------------21
1. 利用土壤試管法觀察子囊孢子發芽 --------------------------------------------21
2. 溫度對子囊孢子發芽的影響 -----------------------------------------------------21
3. 滅菌土壤對子囊孢子發芽的影響 -----------------------------------------------22
a. 高溫高壓滅菌土對子囊孢子發芽的影響 ----------------------------------22
b. 藥劑滅菌土對子囊孢子發芽的影響 ----------------------------------------22
4. 土壤微生物群對子囊孢子發芽的影響 -----------------------------------------22
5. 利用包埋子囊孢子試管法觀察子囊孢子發芽 --------------------------------23
6. 耕作田土壤與非耕作田土壤對子囊孢子發芽的影響 -----------------------24
7. 非土壤介質對子囊孢子發芽的影響 --------------------------------------------24
8. 土壤抽出液對子囊孢子發芽的影響 --------------------------------------------24
9. 植物根的萃取液對子囊孢子發芽的影響 --------------------------------------25
10. 放線菌對子囊孢子發芽的影響 -------------------------------------------------25
三、田間洋香瓜黑點根腐病菌子囊孢子密度調查 ---------------------------------25
1. 田間子囊孢子密度與分布 -------------------------------------------------------25
2. 不同來源土壤中之子囊孢子密度 ----------------------------------------------26
討論 -----------------------------------------------------------------------------------------------27
引用文獻 -----------------------------------------------------------------------------------------33
附表 -----------------------------------------------------------------------------------------------42
附圖 -----------------------------------------------------------------------------------------------56
附錄 -----------------------------------------------------------------------------------------------7
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