STUDIES ON MANGO FRVIT SPOT (II) PATHOGENICITY

檬果果斑病為假單毛菌屬病害，其寄主範圍除檬果、介壽果外，新發現使君子亦為其寄主之一。其病做大小僅1mm以下，為能引起隆起之葉部病斑。 樣果品種間罹病性比較結果，其葉面刺傷按種罹病率均在50%以上，在51~60%者有Julian, Bararnasi及Himsagar四品種，61~70％者有Gadoeng等六品種，71~80%者有Gandem等七品種，81~90％者有Viet-nam（越南種）之等九品種，91％以上者有Singapuri, Hayden, Keitt, Bombay #1四種。 環境因子對致病力之影，試驗顯示，在攝氏32度，相對濕度70%以上時，接種後10天之罹病舉均可達到70%以上，相對濕度90%以上時，病斑呈黑色擴散狀。光照對罹病率之影響，光照為14小時者65.9%，而10」、時者為87.4%，顯示陰天對本病原菌繁准有利。 病原濃度在每公撮含1 × 10 7之細菌個數時效病力最強，而1 × 10 3以下者致病力甚弱，或不發病。 Mango fruit spot disease is caused by Pseadoesotws mangiferae-indicae which induces deep brown stellate spots on fruits and angular, dark brown with raised spots on leaves. The host-s of causal organism reported by Patel el at. in 1948 India, included mango (Marsgifera indica) and czshew nut (Anacardium occiden:ate) , A new host, Ringoon creeper (Qaisqulis indica) was discovered by writer, lately. The symptoms are the ame as described on mango leaves but the width is below 1 mm. along the wound. In screening varieties for susceptibility by needle prick mathod with 1 *10 3 cells/1 ml of suspension on leaves, the percentage of susceptibility was up.to 50 % on all of 30 varieties tested. There were 4 varieties namely Java, St. Julian, Baramasi and llimsagar showing susceptible percentage of 51 to 60%, 6 varieties such as Gadoeng etc. in the range of 61 to 70%, 7 varieties such as Gandem etc in the range of 71 to 80%, 9 varieties such as Vietnam etc. in the range of 81 to 90%, and 4 varieties such as Singapuri, Hayden, Keitt and Bombay No. 1 showing susceptible percentage in the range up to 91%. The experiments on the effects of environmental factors indicated that susceptible percentage might reach up to 70 96 within 10 days after inoculation under the conditions when average temperature was 32℃ and RH was above 70%. However the susceptibility quickly fell down to 50% in 24℃ and 60 96 RH respectively. The average susceptible percentage of 65.9% was recorded in plants which received 14 hours 1000 lux light treatment/each day. Whereas, the 10 hours treatment showed 87.4% susceptibility. The trials on the influence of concentration of suspension on the susceptibility revealed a strung susceptibility if the inoculum concentration was1 x 10 7cells/1 ml. while weak or no susceptibiltty was recorded if it was 1 x 10 3 cells/1 ml, or below

[[alternative]]The Effects of Recreational Sport on Health-Related Fitness of Elementary Higher Grades Students--Using Interesting Rope Skipping activity as Example

[[abstract]]　　本研究探討樂趣化跳繩運動課程對於國小學童健康體適能的影響。　　　本研究採取準實驗設計之不等組前後測，以五十八位國小五年級學童參與本實驗的對象研究，進行為期十二週計畫性的樂趣化跳繩運動課程，其中實驗組進行十二週、每週三天、每天四十分鐘樂趣化跳繩運動課程；對照組不施予任何運動訓練。經過十二週樂趣化跳繩課程測驗所得的前測、後測的數據，以前測成績為共變項，進行「共變數分析檢定」分析兩組體適能。研究結果如下：一、樂趣化跳繩運動課程對於國小學童BMI無顯著影響。二、樂趣化跳繩運動課程對於國小學童柔軟度無顯著影響。三、樂趣化跳繩運動課程對於國小學童瞬發力有顯著影響。四、樂趣化跳繩運動課程對於國小學童肌耐力無顯著影響。五、樂趣化跳繩運動課程對於國小學童心肺適能有顯著影響。　　　經由本研究的分析，樂趣化跳繩活動介入後，學童體適能有所提升，尤其是在心肺適能與瞬發力方面。晨間時間是最能利用的時間，加上跳繩運動場地限制少、費用便宜，實在適合鼓勵學生在校跳繩運動，養成每天規律運動的習慣，強化體適能，培養活力青少年。[[abstract]]　　The purpose of this study was to investigate the effects of interesting rope skipping activity on health physical fitness of the fifth grade students in the elementary school.　　　The fifty-eight students in the fifth grade take part in the experiment study. The experimental group attended interesting rope skipping activity ( 40 min/day, 3 days/week) for twelve weeks; the control group wasn’t trained. The researcher collected the data after twelve weeks training and had statistics by SPSS for Windows Rev.18.0. The analysis was based on Analysis of covariance,（ANCOVA）for figuring out the difference for physical fitness of the groups. The statistic value of this test is α =.05The results of the tests are as follows：1.Interesting rope skipping activity is unable to improve the BMI of elementary school students.2.Interesting rope skipping activity is unable to improve the flexibility of elementary school students. 3.Interesting rope skipping activity is able to improve the power of elementary school students. 4.Interesting rope skipping activity is unable to improve the muscular endurance of elementary school students. 5.Interesting rope skipping activity is able to improve the cardiopulmonary endurance of elementary school students

The Achievement and Prospect of Sweet Potato Breeding in Twiawn

台灣甘藷品種改良工作開始於1911年，在過去數十年問，已有不少的改進和發展，尤其是在品質改進方面，成果更是顯著。其間所育成之甘藷品種共有70餘個，其中10個是目前商品化栽培的品種，為台農57、64、65、66、67、68、69、70號、桃園l號及台南18號。有關甘藷育種基礎研究的成果主要有：甘藷自交和雜交不稔群之檢定；甘藷品種不同組合間之一般和特定組合測定；甘藷開花和結實生理及促進開花之效果；甘藷產量構成之形態和生理因素的相關和路徑係數分析；採用逢機交配族群改進育種方法之效果；甘藷重要質和量性狀之遺傳和相關分析及甘藷田間試驗技術之改進等。 本省甘藷之栽培面積大為減少，但已趨穩定，未來須要進一步努力，繼續使其安定的發展，建議重要的改進項目有：(1)加強甘藷品種改良，應用多向雜交和生物技術方法，育成抗病蟲之高食用品質，優異加工品質，高產及低生產成本的品種；(2)改進甘藷健康苗之培養技術及建立健康種苗之生產體系：(3)加強甘藷遺傳種質資源收集、評估和利用；及(4)開發甘藷產品加工方法和產品有效的利用等。 欲達成前述各項改進工作，必須結合遺傳、育種、病理、昆蟲、生理、生物技術及食品加工技術等之有關重要科學，加強合作努力，則今後甘藷之產業，才能保證獲得更有利的發展。 The sweet potato breeding program in Taiwan was started as early as in 1911. Over 70 cultivars of sweet potato have been released during the past eighty years and the achievement has been especially remarkable in the field of quality improvement. Currently the leading commercial cultivars are Tainung Nos. 57, 64, 65, 66, 67, 68 and 70, Taoyuan No. 1, and Tainan No. 18. Numerous basic studies related to breeding have been carried out by the Chiayi Agriculture Experimental Station in the following fields: the identification of self- and cross incompatibility, the testing of general and specific combining ability among defferent types of cross combinations, the discovery of factors affecting flowering and seed-set, the methods of promoting flowering, the analysis of morphological and physiological yield components through the analysis of correlation and path coefficients, the use of random mating population for the development of superior cutivars, the genetic and correlation analysis of some important quantitative and qualitative traits, and the improvement of field sampling techniques for progeny selection, in addition to a series of yield trials. In view of the decreasing trend in sweet potato production in Taiwan, efforts for improvement and renovation of sweet potato production in the following subjects are suggested: 1) the improvement of cultivars with disease and insect resistance, high eating and processing quality, high productivity, and low production cost by both polycross method and biotechnological approaches; 2) the efficient production of virus-free seedlings through in vitro propagation techniques; 3) the collection, evaluation ,and utilization of genetic resources; and 4) the development of processing methods to widen the utilization scope of sweet potato products

Propagation of Virus-free Sweet Potatoes through Shoot-tip Culture

甘藷感染病毒之病株，以38-42℃熱處理4週以上切取0.3-0.6mm大小之莖頂，培養於含MS基本無機鹽類，每公升添加0.4mg thiamine-HCI、100mg myoinositol，4mg BAP，1mg IAA及30g sucrose之改良式固體MS培養基上，4週後移植於不含生長素之相同培養基，再經1撾，可得完整的培養苗。以指示植物Ipomoea setosa嫁接檢定，剔除病毒殘存株。其餘健康苗，以單莖節培養於改良式MS培養基，每3-4週可繼代培養一次，每次增殖5-6倍，每一莖頂一年約可繁殖40萬苗，對加速健康種苗繁殖，極具功效。 比較健株與罹病株結果發現；具黃斑型及紫斑型病徵之病株，其塊根減產約10%，具捲葉型病徵之病株，嚴重減產30％以上，健株初期生長快，收穫時塊根表皮光滑細緻，肉色亮麗，質量俱佳。 The procedure for producing virus-free sweet potato seedlings by the in vitro .in shoot-tip culture techniques has been established. Shoot tips about 0.3-0.6 mm in length, are excised from the plants previously exposed to high temperature (38~42℃) environment for 28 days. They are cultured for 4 weeks on the medium containing inorganic salts of Murashige and Skoog (MS) formulation supplemened with 0.4mg/l thiamine-HC1, 4 mg/l 6-benzylaminopurine (BAP), 1 mg/l indole -3-acetic acid (IAA), 100 mg/l myo-inositol, 30 g/1 sucrose, and 8 g/l Difco Bactoagar. The cultures are then transferred to medium containing no plant growth regulator, and intact plantlets could be produced within 10 weeks. More than 60% of the produced plantlets are free of virus contamination as proved by mechanical transmission and/or grafting with indicator plants Ipozaoea setosa or I. nil Single-node cuttings of these virus-free plantlets cultured in vitro could develop into intact plants within 20 to 30 days. A 5-time multiplication rate can be achieved after each subculture. A comparison between virus-free and virus-infected plants indicated that the fresh tuber yield was decreased by 30% if the plants were infected with leaf curl virus (SPV-B) and by 10% if infected with yellow spot symptom virus (SPV-A) and/or mild mottle symptom virus (SPV-N). The virus-free plants were also characterized by higher growth rate at early growth phase and better tuber quality

The Improvement of Cultural Practice for Sweet Potato production

影響甘藷產量及品質的因子，可分為人為和自然因子兩類，人為因子為品種、栽培技術及輪作制度。自然因子為氣候、土壤生產力和肥力等。選用適地適作已經推廣栽培的優良品種，並針對該優良品種的特性，配合適當的栽培管理方法，如採用優良藷苗、適當插植時期和方法、合理的種植密度、適量適時的施肥、適度適時的灌溉，適時防治病蟲害及適時培土等，這些都是提高甘藷質和量生產的重要條件。目前由於農村耕作勞力的不足，運用現有可行的適當農機具，使生產過程中重要的栽培作業，達到機械化，也是增加生產利益的重要工作，在計畫生產時，必須注意不同季節和不同用途之產品市場的需求情形，做好產期調節，才能達成生產的好處。甘藷有良好的營養價值，然而如何使其生產和利用相互結合，是應加以重視的問題。 Factors affecting the yield and quality of sweet potato can be classified into two groups; those factors originated from the nature include climate, soil productivety and fertility, and the prevalence of insects and diseases. Impacts from the human beings include varietal performance, cultural practices, and other measures such as capital investment and consumers¡¦ preference. The enhancement in yield and quality of any crop can be achieved by developing varieties capable of matching the environmental conditions under appropriate cultural practices. For sweet potato, major concerns related to cultural practices include the selection of high quality vine cuttings and the optimum decision in planting time, planting method, planting density, fertilization, irrigation, soil banking, and insect and disease management. Due to the shortage of farm labor, the development of mechanization, especially for planting and harvesting, is also essential to the successful production of sweet potato. In order to increase farmers’ profit, the adjustment of harvest time to meet market demand should be considered. Sweet potato is a better diet as compared to rice in terms of its higher nutritional value and dietary fiber content and lower calorie content. Studies are needed to expand its utilization and to develop modern processing techniques in order to facilitate the production of this important food crop