Screening Cultivated Eggplant and Wild Relatives for Resistance to Bacterial Wilt (Ralstonia solanacearum)

[EN] Bacterial wilt, caused by Ralstonia solanacearum, is highly diverse and the identification of new sources of resistance for the incorporation of multiple and complementary resistance genes in the same cultivar is the best strategy for durable and stable resistance. The objective of this study was to screen seven accessions of cultivated eggplant (Solanum melongena L.) and 40 accessions from 12 wild relatives for resistance to two virulent R. solanacearum strains (Pss97 and Pss2016; phylotype I, race 1, biovar 3). The resistant or moderately resistant accessions were further evaluated with Pss97 in a second trial under high temperatures (and also with Pss2016 for S. anguivi accession VI050346). The resistant control EG203 was resistant to Pss97, but only moderately resistant to Pss2016. One accession of S. sisymbriifolium (SIS1) and two accessions of S. torvum (TOR2 and TOR3) were resistant or moderately resistant to Pss97 in both trials. Solanum anguivi VI050346, S. incanum accession MM577, and S. sisymbriifolium (SIS1 and SIS2) were resistant to Pss2016 in the first trial. However, S. anguivi VI050346 was susceptible in the second trial. These results are important for breeding resistant rootstocks and cultivars that can be used to manage this endemic disease.This research was funded by the Global Crop Diversity Trust] grant number [GS17011] and World Vegetable Center core funds. This work was undertaken as part of the initiative Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew UK and implemented in partnership with national and international genebanks and plant breeding institutes around the world. For further information, go to the project website: http://www.cwrdiversity.org/. This work has also been funded in part by World Vegetable Center core funds from Republic of China (Taiwan), UK aid, United States Agency for International Development (USAID), Australian Centre for International Agricultural Research (ACIAR), Germany, Thailand, Philippines, Korea, and Japan.Namisy, A.; Chen, J.; Prohens Tomás, J.; Metwally, E.; Elmahrouk, M.; Rakha, M. (2019). Screening Cultivated Eggplant and Wild Relatives for Resistance to Bacterial Wilt (Ralstonia solanacearum). Agriculture. 9(7):1-11. https://doi.org/10.3390/agriculture9070157S11197Genin, S., & Denny, T. P. (2012). Pathogenomics of theRalstonia solanacearumSpecies Complex. Annual Review of Phytopathology, 50(1), 67-89. doi:10.1146/annurev-phyto-081211-173000Huet, G. (2014). Breeding for resistances to Ralstonia solanacearum. Frontiers in Plant Science, 5. doi:10.3389/fpls.2014.00715Peeters, N., Guidot, A., Vailleau, F., & Valls, M. (2013). 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Bacterial Wilt Resistance in Tomato, Pepper, and Eggplant: Genetic Resources Respond to Diverse Strains in the Ralstonia solanacearum Species Complex. Phytopathology®, 101(1), 154-165. doi:10.1094/phyto-02-10-0048Pradhanang, P. M., Ji, P., Momol, M. T., Olson, S. M., Mayfield, J. L., & Jones, J. B. (2005). Application of Acibenzolar-S-Methyl Enhances Host Resistance in Tomato Against Ralstonia solanacearum. Plant Disease, 89(9), 989-993. doi:10.1094/pd-89-0989Fujiwara, A., Fujisawa, M., Hamasaki, R., Kawasaki, T., Fujie, M., & Yamada, T. (2011). Biocontrol of Ralstonia solanacearum by Treatment with Lytic Bacteriophages. Applied and Environmental Microbiology, 77(12), 4155-4162. doi:10.1128/aem.02847-10Addy, H. S., Askora, A., Kawasaki, T., Fujie, M., & Yamada, T. (2012). Utilization of Filamentous Phage ϕRSM3 to Control Bacterial Wilt Caused by Ralstonia solanacearum. Plant Disease, 96(8), 1204-1209. doi:10.1094/pdis-12-11-1023-reKeatinge, J. D. H., Lin, L.-J., Ebert, A. W., Chen, W. 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M., Fonseka, H. H., Vilanova, S., … Prohens, J. (2015). Improving seed germination of the eggplant rootstock Solanum torvum by testing multiple factors using an orthogonal array design. Scientia Horticulturae, 193, 174-181. doi:10.1016/j.scienta.2015.07.030Hayward, A. C. (1964). Characteristics ofPseudomonas solanacearum. Journal of Applied Bacteriology, 27(2), 265-277. doi:10.1111/j.1365-2672.1964.tb04912.xCook, D. (1989). Genetic Diversity ofPseudomonas solanacearum: Detection of Restriction Fragment Length Polymorphisms with DNA Probes That Specify Virulence and the Hypersensitive Response. Molecular Plant-Microbe Interactions, 2(3), 113. doi:10.1094/mpmi-2-113He, L. Y. (1983). Characteristics of Strains ofPseudomonas solanacearumfrom China. Plant Disease, 67(12), 1357. doi:10.1094/pd-67-1357Kado, C. I. (1970). Selective Media for Isolation of Agrobacterium, Corynebacterium, Erwinia, Pseudomonas, and Xanthomonas. Phytopathology, 60(6), 969. doi:10.1094/phyto-60-969Hanson, P. M., Wang, J.-F., Licardo, O., Mah, S. Y., Hartman, G. L., … Lin, Y.-C. (1996). Variable Reaction of Tomato Lines to Bacterial Wilt Evaluated at Several Locations in Southeast Asia. HortScience, 31(1), 143-146. doi:10.21273/hortsci.31.1.143Aslam, M. N., Mukhtar, T., Hussain, M. A., & Raheel, M. (2017). Assessment of resistance to bacterial wilt incited by Ralstonia solanacearum in tomato germplasm. Journal of Plant Diseases and Protection, 124(6), 585-590. doi:10.1007/s41348-017-0100-1. M. A. R., . M. A. R., . M. M. H., . M. A. S., & . A. S. M. H. M. (2002). Grafting Compatibility of Cultivated Eggplant Varieties with Wild Solanum Species. Pakistan Journal of Biological Sciences, 5(7), 755-757. doi:10.3923/pjbs.2002.755.757Plazas, M., Vilanova, S., Gramazio, P., Rodríguez-Burruezo, A., Fita, A., Herraiz, F. J., … Prohens, J. (2016). Interspecific Hybridization between Eggplant and Wild Relatives from Different Genepools. Journal of the American Society for Horticultural Science, 141(1), 34-44. doi:10.21273/jashs.141.1.34GRAMAZIO, P., PROHENS, J., PLAZAS, M., MANGINO, G., HERRAIZ, F. J., GARCÍA-FORTEA, E., & VILANOVA, S. (2018). Genomic Tools for the Enhancement of Vegetable Crops: A Case in Eggplant. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 46(1), 1-13. doi:10.15835/nbha46110936PRIOR, P., BART, S., LECLERCQ, S., DARRASSE, A., & ANAIS, G. (1996). Resistance to bacterial wilt in tomato as discerned by spread of Pseudomonas ( Burholderia ) solanacearum in the stem tissues. Plant Pathology, 45(4), 720-726. doi:10.1046/j.1365-3059.1996.d01-9.

A total solid-phase synthesis of DILP8

We have developed a cysteine anchoring method for the synthesis of DILP8 and its analogues. The first is to synthesis of DILP8A SS13-18, C14-MeOBzl, C24-Acm and activate it as DILP8A S13-18, C14-SSPyr C24-Acm. A next step is to synthesize the DILP8BC16-Acm. The desired peptide, DILP8 with Cys(Acm) at A-24 and B-16, was then dissolved in 75% HOAc by addition of Iodine in MeOH and 4M HCl in dioxane. The reaction mixture was monitored by HPLC and the excess iodine was reduced with ascorbic acid. Purification of the peptide was achieved by HPLC. Pure synthetic DILP8 showed a single peak on analytical HPLC with corrected molecular ion. By using the above methods, enough peptide and highly homogenous pure DILP8 were generated

Development of Interspecific Hybrids between a Cultivated Eggplant Resistant to Bacterial Wilt (Ralstonia solanacearum) and Eggplant Wild Relatives for the Development of Rootstocks

[EN] Bacterial wilt caused by Ralstonia solanacerum is one of the most economically and destructive eggplant diseases in many tropical and subtropical areas of the world. The objectives of this study were to develop interspecific hybrids, as potential rootstocks, between the eggplant (Solanum melongena) bacterial wilt resistant line EG203 and four wild accessions (S. incanum UPV1, S. insanum UPV2, S. anguivi UPV3, and S. sisymbriifolium UPV4), and to evaluate interspecific hybrids along with parents for resistance to bacterial wilt strains Pss97 and Pss2016. EG203 was crossed successfully with wild accessions UPV2 and UPV3 and produced viable seeds that germinated when wild accessions were used as a maternal parent in the crosses. In addition, viable interspecific hybrids between EG203 and UPV1 were obtained in both directions of the hybridization, although embryo rescue had to be used. Hybridity was confirmed in the four developed interspecific hybrid combinations with three SSR markers. EG203 was resistant to both strains Pss97 and Pss2016, while UPV1 and UPV3 were, respectively, resistant and moderately resistant to Pss2016. The four interspecific hybrids with UPV2, UPV3, and UPV1 were susceptible to both bacterial wilt strains, indicating that the resistance of EG203, UPV1, and UPV3 behaves as recessive in interspecific crosses. However, given the vigor of interspecific hybrids between eggplant and the three cultivated wild species, these hybrids may be of interest as rootstocks. However, the development of interspecific hybrid rootstocks resistant to bacterial wilt will probably require the identification of new sources of dominant resistance to this pathogen in the eggplant wild relatives.This research and the APC were funded by Global Crop Diversity Trust [GS20001]. This work was undertaken as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing CropWild Relatives" which is supported by the Government of Norway. The project is managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens, Kew UK and implemented in partnership with national and international genebanks and plant breeding institutes around the world. For further information, go to the project website: http://www.cwrdiversity.org/.This work has also been funded in part byWorldVeg Innovation Fund project through core funds from China (Taiwan), UK aid, United States Agency for International Development (USAID), Australian Centre for International Agricultural Research (ACIAR), Germany, Thailand, Philippines, Korea, and Japan.Rakha, M.; Namisy, A.; Chen, J.; El-Mahrouk, ME.; Metwally, E.; Taha, N.; Prohens Tomás, J.... (2020). Development of Interspecific Hybrids between a Cultivated Eggplant Resistant to Bacterial Wilt (Ralstonia solanacearum) and Eggplant Wild Relatives for the Development of Rootstocks. Plants. 9(10):1-13. https://doi.org/10.3390/plants9101405S11391

Exploring the genetic makeup of Xanthomonas species causing bacterial spot in Taiwan: evidence of population shift and local adaptation

The introduction of plant pathogens can quickly reshape disease dynamics in island agro-ecologies, representing a continuous challenge for local crop management strategies. Xanthomonas pathogens causing tomato bacterial spot were probably introduced in Taiwan several decades ago, creating a unique opportunity to study the genetic makeup and adaptive response of this alien population. We examined the phenotypic and genotypic identity of 669 pathogen entries collected across different regions of Taiwan in the last three decades. The analysis detected a major population shift, where X. euvesicatoria and X. vesicatoria races T1 and T2 were replaced by new races of X. perforans. After its introduction, race T4 quickly became dominant in all tomato-growing areas of the island. The genomic analysis of 317 global genomes indicates that the Xanthomonas population in Taiwan has a narrow genetic background, most likely resulting from a small number of colonization events. However, despite the apparent genetic uniformity, X. perforans race T4 shows multiple phenotypic responses in tomato lines. Additionally, an in-depth analysis of effector composition suggests diversification in response to local adaptation. These include unique mutations on avrXv3 which might allow the pathogen to overcome Xv3/Rx4 resistance gene. The findings underscore the dynamic evolution of a pathogen when introduced in a semi-isolated environment and provide insights into the potential management strategies for this important disease of tomato

Characterization of Phytophthora capsici associated with Phytophthora blight of pepper and resistance screening in Taiwan

番椒疫病 (Phytophthora blight) 由Phytophthora capsici L. 所引起，是全球番椒 生產的主要限制因子之一。已有學者利用不同基因型 (genotype) 的番椒品種/品系 做為鑑別寄主 (differential host)，鑑定病原菌的病原型，目前對番椒疫病菌病原型 的鑑定已普遍應用於抗病育種上。台灣自 2007 年陸續於茄子、番茄和番椒中分離 到番椒疫病菌 A2 配對型菌株。滅達樂是防治此病害的主要化學藥劑，在台灣以滅 達樂相關藥劑防治卵菌綱病原菌所造成的病害已超過 20 年的歷史。進行這個研究 的目的是1.) 要瞭解台灣番椒疫病菌株的生物特性，包括病原型、配對型的特性和 對滅達樂的感受性，2.) 篩選抗病品種，包括篩選抗病種原和評估亞蔬高級品系的 抗性。此研究利用四種不同基因型的番椒品種/品系 Early Calwonder、PBC 137、PBC 602 sel 和 PI 201234 做為鑑別寄主，以根部及培養土澆灌方式接種後，將自台灣 蒐集的番椒疫病菌共區分為 3 個不同的病原型，即病原型 1、2 和 3，目前在台 灣以病原型 3 的菌株為毒力最強且優勢的族群。病原型 3 的菌株在 PDA 和 V8 培養基平板上培養的生長速度都比病原型 1 和 2 緩慢。病原型 1 菌株的孢囊比 病原型 2 和 3 菌株的孢囊小而且圓。病原型 1 的孢囊平均為 43±3 × 33±2 μm， 長寬比值為 1.3±0.06；病原型 2 的孢囊平均為 50±6 × 35±5 μm，長寬比值為 1.4±0.09；病原型 3 的孢囊平均為 49±4 × 33±3 μm，長寬比值為 1.5±0.15。利用分 子檢測技術鑑定病原型，以 P. capsici 誘導蛋白設計引子對 (PcE/PcER) 進行聚合酶連鎖反應和增幅片段長度多形性分析 P. capsici 不同病原型之核酸多形性的結果，可將供試菌株明顯地區分為 2 個分子群，分子群 1 為病原型 1，分子群 2 為病原型 2 和 3。進行台灣番椒疫病菌株 A1 和 A2 配對型之特性比較，結果顯示A2 配對型菌株在 PDA 及 V8 平板上培養的生長速度皆比 A1 配對型菌株緩慢；A2 配對型菌株於 36℃ 高溫下仍能生長、孢囊較 A1 配對型的孢囊大 (A2 配對型的孢囊平均為 50±3 x 31±2 μm； A1 配對型的孢囊平均為 47±5 x 35±3 μm) 且狹長 (A2 配對型的長/寬比值為 1.6±0.07；A1 配對型的長/寬比值為 1.4±0.08)。 A2 配對型菌株只有病原型 2 及 3，常造成較嚴重的罹病度，而目前田間番椒疫病菌株以 A1 配對型為較優勢之族群。評估台灣番椒疫病菌對滅達樂的感受性之檢測結果，得知台灣大部分番椒疫病菌對滅達樂感受性屬敏感性 (68.7%)。另將所有菌株區分為 2008 年以前收集的菌株與 2008 當年收集的菌株進行比較，菌株對滅達 樂的抗性有大幅提升的趨勢，百分率由 3 % 提升至 43.4 %。測試三種病原型對滅達樂感受性，則以病原型 1 菌株 (66.7%) 較抗滅達樂。若另以 2008 年收集的菌株區分為 A1 和 A2 配對型菌株進行評估，55.3 % A1 配對型菌株具抗藥性，A2配對型菌株則只有 13.3 % 具抗藥性，這顯示 A2 配對型菌株對滅達樂較敏感。本 次篩選抗病種原之研究是由亞蔬-世界蔬菜中心種原組 (Genetic resources and seed unit; GRSU) 提供 5 個不同種 (Capsicum baccatum、C. chacoense、C. chinense、C. frutescens 和 C. pubescens) 的野生番椒及一個栽培種 C. annuum 總共 785 個種原 (accession)。全部種原均以根部及培養土澆灌方法接種疫病菌進行篩選，獲得野生番椒 C. frutescens 的 1 個種原 TC05415 之抗病植株子代抗病百分率達94 % 以上。其次評估亞蔬高級番椒品系之抗病性，由亞蔬-世界蔬菜中心番椒育種組(pepper unit) 提供 75 個高級品系也同樣進行根部及培養土澆灌接種疫病菌，結果篩選獲得 6 個高級品系之子代(F8)，抗病百分率達 87.5 % 以上，其中 7 個子代抗病百分率仍維持在 100 %。在本試驗篩選得到的抗病種原，可以提供番椒育種單位作為抗病育種的親本，而篩選的高抗病性之高級品系則可經由區域試驗檢測其抗病穩定性及園藝性狀，以作為未來推廣達到防治疫病之目的。目前田間番椒疫病菌株以病原型3 為較優勢族群，2008 年番椒疫病菌A2 配對型菌株的出現對番椒所造成的影響到目前尚未完全了解，然而A2 配對型菌株較能耐高溫、產生較多的游走孢子、且造成較嚴重的罹病度，對台灣的番椒可能造成嚴重危害。A1 和A2 配對型菌株行有性繁殖，基因重組使其遺傳特性更趨複雜，將使未來防治這個病害更加得困難，顯示對病原菌族群變化的監視、加強抗病種原的篩選與培育抗病品種是刻不容緩的工作。Phytophthora blight of pepper (Capsicum spp.) caused by Phytophthora capsici L. is one of the major limiting factor of pepper production worldwide. Several reports had identified the existence of pathogenic specificity of P. capsici on peppers. Pathotypes are determined by the pathogen reaction to a set of differential hosts. The identification of the pathotype of P. capsici has been commonly used the breeding program for disease resistance. Our previous studies indicated that only the A1 mating type isolates of P. capsici was found in Taiwan befoe 2007. The A2 mating type isolates were found on tomato, eggplant and pepper since 2007. Metalaxyl related chemicals have been used in the control of many different oomycete pathogens more than 20 years in Taiwan. The objectives of this study are: i.) To understand the characteristics of P. capsici on pepper in Taiwan including the characterizations of pathotype, mating type and in vitro assessment of metalaxyl sensitivity and ii.) To screen the resistance variety from wild peppers and to evaluate the resistance of AVRDC advanced lines for disease control. Four pepper varieties/lines, Early Calwonder, PBC 137, PBC 602 sel and PI 201234, were used as indicator plants to classify all of P. capsici isolates into three pathotypes, type1, 2 and 3. Pathotype 3 showed the highest virulence and was the predominant population in Taiwan. The growth rate of pathotpe 3 was slowler than pathotype 1 and 2 on both PDA and V8 plates. Pathotype 1 isolates produced small and round sporangia (43±3 × 33±2 μm, L/B: 1.3±0.06). The sporangia of pathotype 2 were 50±6 × 35±5 μm, L/B: 1.4±0.09, while those of pathotype 3 were 49±4 × 33±3 μm, L/B: 1.5±0.15. Pathotype 1 was significantly different from pathotype 2 and 3 based on PCR polymorphisms using primers from P. capsici elicitin and AFLP analysis. The comparison of the difference of morphology, zoospore productivity, growth rate, pathogenicity between A1 and A2 mating type isolates of P. capsici showed that the growth rate of the A2 mating type isolates was slower than A1 mating type in both PDA and V8 plates. The A2 mating type isolates produced larger and oval sporangia (50±3 x 31±2 um; L/B: 1.6), and grew even at 36℃. These isolates caused more severe disease because they belonged to either pathotype 2 or 3. A1 mating type was the predominant type in Taiwan. In vitro assessment of metalaxyl sensitivity of P. capsici isolates indicated that 68.7 % of the isolates were classified as sensitive. The only 3 % isolates collected before 2008 were resistant to metalaxyl, while 43.4 % of those collected in 2008 were resistant to metalaxyl. Most pathotype 1 isolates (66.7 % resistant) were resistant to metalaxyl than pathotype 2 and 3 isolates (7.0 % and 15.1 % respectively). More A2 mating type isolates (13.3% resistant) were sensitive to metalaxyl than A1 isolates (55.3% resistant). Resistance screening of wild germplasms collected from GRSU (Genetic resources and seed unit) of AVRDC and evaluation of resistance in AVRDC advanced lines by root-drench noculation were conducted. One wild accessions of TC05415 in Capsicum frutescens showing resistant percentage higher than 94 % were selected. Six progeny lines (F8) of AVRDC advanced lines exhibited resistant percentage higher than 87.5% and 7 progeny lines of AVRDC advanced lines exhibiting 100 % resistance were selected. The resistant accessions can be used as the resistant parent in the breeding program for disease resistance. Those resistant advanced lines will be evaluated for durable resistance and horticultural traits for the future extension. The impact of the occurrence of the A2 mating type on peppers is not yet clear in Taiwan because it first appeared only in 2008. However, the A2 mating type isolates with tolerance to high temperature and ability to produce more zoospores as well as the genetic variation followed by sexual recombination between A1 and A2 mating types may lead to the difficulties of disease control in the future. Therefore, it's important to monitor the population shift of P. capsici and develop the resistant varieties of pepper for the effective control of phytophthora blight.中文摘要 .....................................................................................................................i 英文摘要 ....................................................................................................................iv 目錄 ...........................................................................................................................vii 表次目錄......................................................................................................................xi 圖次目錄......................................................................................................................xii 第一章：前人研究 ....................................................................................................1 引用文獻 ......................................................................................................5 第二章：台灣番椒疫病菌 (Phytophthora capsici) 生物特性之探討 ...................9 中文摘要 .....................................................................................................................9 英文摘要 ...................................................................................................................12 前言 ...........................................................................................................................15 材料和方法 ...............................................................................................................19 供試菌株的蒐集 ..............................................................................................19 菌株種類的鑑定 ..............................................................................................19 供試植株的準備 ..............................................................................................21 游走孢子接種源的製備與接種 ......................................................................21 I. 病原型 (pathotype) 特性之探討 ......................................................................21 病害等級的調查與病原型的鑑定 ..................................................................22 不同病原型之培養特性比較 ..........................................................................22 1. 在 PDA 及 V8 培養基平板之菌落形態與生長速度 ..........................22 2. 孢囊大小與形狀之比較 ..........................................................................22 3. 溫度對游走孢子產量之影響 ..................................................................23 利用分子檢測技術分析不同病原原型 P. capsici 之核酸多形性 ...............23 1. 聚合酶連鎖反應 (polymerase chain reaction; PCR) 多形性分析 ........23 viii 2. 增幅片段長度多形性 (amplified fragment length polymorphism; AFLP) 分析 ..........................................................................................................24 II. A1 和A2 配對型特性之探討 ...........................................................................25 菌株的配對型鑑定 ...........................................................................................25 生長形態特性 ...................................................................................................25 孢囊大小與形狀的觀察和在 28℃ 環境中的產孢量 ...................................26 兩種配對型的病原型評估 ...............................................................................27 III. 生體外評估番椒疫病菌對殺菌劑滅達樂之感受性 ......................................27 結果 ............................................................................................................................28 菌株種類的鑑定 ..................................................................................................28 I. 病原型 (pathotype) 特性之探討 ......................................................................28 病原型的鑑定 ...................................................................................................28 不同病原型之培養特性比較 ...........................................................................28 1. 在 PDA 及 V8 培養基平板之菌落形態與生長速度 ..........................28 2. 孢囊大小與形狀之比較 ...........................................................................29 3. 溫度對游走孢子產量之影響 ...................................................................29 利用分子檢測技術分析不同病原原型 P. capsici 之核酸多形性 ................29 1 聚合酶連鎖反應 (polymerase chain reaction; PCR) 多形性分析 ..........29 2 增幅片段長度多形性 (amplified fragment length polymorphism; AFLP)分 析 .................................................................................................................30 II. A1 和A2 配對型特性之探討 ...........................................................................30 菌株的配對型鑑定與所屬病原型 ................................................................30 生長形態特性..................................................................................................30 孢囊大小及形狀的觀察和在 28℃ 環境中的產孢量 ................................31 III. 生體外評估番椒疫病菌對殺菌劑滅達樂之感受性 ......................................31 討論 ...........................................................................................................................33 引用文獻 ...................................................................................................................37 表格說明 ...................................................................................................................43 圖示說明 ...................................................................................................................54 第三章：利用寄主抗病性防治疫病 .......................................................................64 中文摘要 ...................................................................................................................64 英文摘要 ...................................................................................................................65 前言 ...........................................................................................................................66 材料和方法 ...............................................................................................................69 自野生的番椒中篩選抗病種原 ............................................................................69 供試菌株 ..........................................................................................................69 供試植株 ..........................................................................................................69 游走孢子接種源的製備與接種 ......................................................................69 病害嚴重度的調查與抗病百分率之計算 ......................................................70 亞蔬高級番椒品系的抗病性評估 ........................................................................70 供試菌株 ..........................................................................................................70 供試植株 ..........................................................................................................70 游走孢子接種源的製備與接種 ......................................................................71 病害嚴重度的調查與抗病百分率之計算 ......................................................71 結果 ...........................................................................................................................72 自野生的番椒中篩選抗病種原 ......................................................................72 亞蔬高級番椒品系的抗病性評估....................................................................72 討論 ...........................................................................................................................74 引用文獻 ...................................................................................................................76 表格說明 ...................................................................................................................79 圖示說明 ...................................................................................................................83 第四章：結論 ...........................................................................................................86 附錄一 .......................................................................................................................8

Evaluation of Resistance Sources of Tomato (Solanum lycopersicum L.) to Phylotype I Strains of Ralstonia solanacearum Species Complex in Benin

Finding sources of resistance to bacterial wilt (BW) caused by Ralstonia solanacearum species complex is a crucial step toward the development of improved bacterial wilt-resistant tomato varieties. Here, we evaluated new sources of bacterial wilt-tolerant/resistant tomato lines and identified associated phylotype/sequevar of R. solanacearum strains in Benin. Eighteen F5 lines and five checks were evaluated in two hotspots: the experimental site of the World Vegetable Center, Cotonou Benin, and the Laboratory of Genetics, Biotechnology and Seed Science of the University of Abomey-Calavi. Experiments were laid out in a randomized complete block design with four replicates. Data were collected on bacterial wilt incidence, horticultural and fruit traits and yield components. Across the two experiments, the F5 lines showed no wilting, while the local variety ‘Tounvi’ used as susceptible check showed 57.64% wilting. The wilting was due to BW and was associated with sequevars I-14, I-18 and I-31 of phylotype I. AVTO1803, AVTO1955-6 and H7996 were the highest yielding lines with 20.29 t·ha−1, 17.66 t·ha−1 and 17.07 t/ha, respectively. The sources of resistance to BW can be recommended to national agricultural system for dissemination or used in tomato breeding programs

Taiwan consensus statement on the management of chronic hepatitis B

The experts of Taiwan Association for the Study of Liver (TASL) have actively participated and led the guidelines on hepatitis B virus (HBV) management by Asian Pacific Association for the Study of Liver (APASL) which is the first international association for the study of liver to publish the statement on HBV management before. However, there are more and more new data on the natural history and treatment of HBV infection in the past decade. These include new application of an old biomarker (quantitative HBsAg), clinical significance of HBV genotype and naturally occurring mutations, the role of non-invasive examination in evaluating severity of hepatic fibrosis, clinical significance of outcome calculators, new drug or new combination strategies towards more effective therapy and organ transplantation including liver and non-liver transplantation. It is time to publish the guidelines on HBV management of Taiwan. Hence, TASL have conducted an expert meeting to review, to discuss and to debate the relevant literatures, followed by draft the manuscript of HBV management guidelines and recommendations. The guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patient receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included. Keywords: Chronic hepatitis B, Pegylated interferon alfa, Entecavir, Tenofovir disoproxil fumarate, Tenofovir alafenamid