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題名 | 臺灣青枯病菌之雜草寄主=Weed Hosts of Ralstonia solanacearum in Taiwan |
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作者 | 林駿奇; 徐世典; 曾國欽; Lin, J. C.; Hsu, S. T.; Tzeng, K. C.; |
期刊 | 植物保護學會會刊 |
出版日期 | 19991200 |
卷期 | 41:4 1999.12[民88.12] |
頁次 | 頁277-292 |
分類號 | 433.4 |
語文 | chi |
關鍵詞 | 青枯病; 雜草寄主; Bacterial wilt; Ralstonia solanacearum; Weed hosts; |
中文摘要 | 雜草可當作青枯病菌(Ralstonia solanacearum)的中間寄主或在青枯病菌的長期存活上扮演重要角色。本研究在探討臺灣田間是否存有青枯病菌的可能雜草寄主。由臺灣各地區選擇無寄主作物生長或無罹病作物發生的73塊田,隨機採集共78種1844棵雜草,以選擇性培養基可從菁芳草、紫花霍香薊、霍香薊、鬼針草、昭和草、香附子、水蜈蚣、水丁香及飛揚草等9種雜草21棵植株的根部分離到青枯病菌。這些雜草在田間均無病徵,且其帶菌率除菁芳草(25%)及水蜈蚣(14.2%)外,其餘均低(2.2-6.6%)。所有雜草分離的菌株皆屬於第一生理小種及第三生物型,在生理生化特性上與作物來源之菌株相似。田間常出現的14種供試雜草包括上述帶菌者,以莖部穿刺法及土壤澆菌法接種時,多數雜草會出現萎凋病徵,屬於感病性,尤其菁芳草、昭和草、香附子、水蜈蚣、馬齒莧及龍葵等雜草對大多數菌株極為感病,但有些雜草如水丁香、飛提草、一支香及腋下珠的所有或絕大多數接種植株均無病徵,屬於高抗病性。另外少數雜草如苦□,對有些菌株表現高感病性,但對其他菌株則為高抗病性。以土壤澆菌法接種時,上述無病徵表現的抗病雜草中,除水丁香及飛揚草外,其餘大多數或部分植株的根部及莖部內可偵測到病菌之存在。土壤中的青枯病菌偉入感病性雜草的根部後,在根部及莖部內的增殖快速;在根圈中,菌量的變化雖不大,但在五週測試時間內,可維持高菌量(約10��-10�箱fu/g soil)。本研究結果顯示無病徵帶菌雜草存在於臺灣某些非發病農田,而感病性及無病徵表現但可被系統感染的雜草皆為青枯病菌可能之寄主。 |
英文摘要 | Weed plants may serve as alternative hosts of Ralstonia solanacearum or play an important role in the long-term survival of the pathogen in fields devoid of susceptible host crops. This study was undertaken to determine potential weed hosts for the pathogenic bacterium in Taiwan. Weed plants were randomly collected from fields and roots were assayed for the presence of R. solanacearum. The fields were randomly selected where no host crops were growing or no diseased crop plants were observed. a total of 1844 weed plants belonging to 78 species in 23 families were collected from 73 fields at various localities of Taiwan. R. solanacearum was only isolated from roots of 21 plants representing nine species: Ageratum conyzolides, Ageratum houstonianum, Bidens bipinnata, Crassocephlum crepidioides, Cyperus rotundus, Drymaria cordata, Euphorbia hirta, Kyllinga brevifolia, and Ludwigia octovalis. All of these plants were symptomless carriers, and were found only in few fields. The rates of positive isolation from these weeds were generally low, ranging from 2.2 to 6.6%, with the exceptions of D. cordata (25%) and K. brevifolia (14.2%). All strains of R. solanacearum from weeds were classified as race 1 and biovar 3, and their phenotypic characteristics were similar to those strains from rops. Fourteen common weeds tested including the above symptomless carriers varied in their susceptibility to R. solanacerum when artificially inoculated by stem-rick and soil-drenching methods. D. cordata, C. crepidioides, C. rotundus, K. brevifolia, Portulaca oleracea and Solanum nigrum were the most susceptible, showing rapid wilting after stem inoculation with most of strains (16 strains tested), while E. hirta, L. octovalis, Verononia cinerea and Phyllanthus urinaria were most resistant, exhibiting no symptoms in all or most of the inoculated plants. In addition, Physalis angulata was highly susceptible to some strains but was highly resistant to others. R. solanaceaurm was detected in roots and stems of nearly all or some of symptomless plants of the resistant weeds except in those of E. hirta and L. octovalis, when they were inoculated by the soil-drenching method. R. solanacearum multiplied and its population increased rapidly in roots and stems of susceptible weeds after planting in the infested soil, and high population levels also maintained in the rhizospheres within the five weeks tested period. The results indicate that symptomless weeds that carried R. solanacearum occur in some fields not known to be infested, and that susceptible weeds and the symptomless weeds that could be systemically infected are potential hosts of R. solanacerum in Taiwan. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。