頁籤選單縮合
題名 | 香椿與食茱萸苗木疫病=Phytophthora Diseases of Cedrela sinensis and Zanthoxylum ailanthoides |
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作者 | 安寶貞; 蔡志濃; 王姻婷; | 書刊名 | 臺灣農業研究 |
卷期 | 62:1 2013.03[民102.03] |
頁次 | 頁57-70 |
分類號 | 433.4 |
關鍵詞 | 香椿; 食茱萸; 疫病; Cedrela sinensis; Zanthoxylum ailanthoides; Phytophthora diseases; Phytophthora nicotianae; Phytophthora palmivora; |
語文 | 中文(Chinese) |
中文摘要 | 2006年起發現多處地區的香椿(Cedrela sinensis)與食茱萸(紅刺蔥) (Zanthoxylum ailanthoides)苗木發生嚴重枯萎腐敗現象。香椿的罹病部位包括莖基部與根系;莖基部染病後,基部隘縮,繼而全株枯萎死亡,而在環境潮濕時,罹病部位長出白色霉狀物;根部染病時,根系壞疽且稀少,嚴重時地上部矮化黃葉,甚而全株死亡。食茱萸則全株可被感染,包括根、莖及葉片,被感染葉片初現淡褐色水浸狀圓形斑點,病斑面積迅速擴大轉為暗褐色,並提早落葉;莖部被感染時,新稍與主莖初現褐色病斑,而後擴大環繞莖部,造成頂芽與罹病處以上部位枯死;莖基部與根系的病徵則與香椿受害情形相似。罹病組織經分離,從香椿上獲得兩種疫病菌,分別為Phytophthora nicotianae(P. parasitica)與Phytophthora palmivora,而食茱萸上分離到的疫病菌則全為P. nicotianae。將分離到的疫病菌游走子懸浮液各自噴霧接種於兩種作物一年生幼苗上,2-3 d後均會造成新稍褐變枯萎、葉片出現褐斑後掉落;接種莖基部時,10-14 d則可造成組織隘縮與植株死亡;接種根部時,約20-30 d則可造成植株死亡;均與田間出現之病徵一致,並且自接種後發病的組織上均可回分到相同的疫病菌,證實香椿與食茱萸的莖、葉及根系腐敗係由疫病菌引起。兩種疫病菌均為典型(typical type)疫病菌,P. nicotianae的菌絲生長溫度為8-36℃,最適溫為28℃;孢囊球形或橢圓形,具顯著乳突(papilla)及不脫落性;P. palmivora的菌絲生長溫度為12-35℃,最適溫亦為28℃;孢囊橢圓形、檸檬形或卵圓形,具顯著乳突及脫落性,孢囊柄 (pedicels)極短,在5 μm以下。兩種疫病菌均可形成厚膜孢子 (chlamydospores)。其中香椿分離的P. nicotianae為2株A^1配對型(mating type),而P. palmivora為3株A^2配對型;而食茱萸分離的P. nicotianae包括7株A^1與4株A^2配對型。利用分子序列特性,包括核糖體內轉錄區間(ITS)DNA序列與β微管蛋白(β-tubulin)部分基因序列分析,序列比對結果亦佐證傳統形態分類的正確性。本研究結果係疫病菌為害香椿與食茱萸的首度報導。 |
英文摘要 | Serious Phytophthora diseases of Cedrela sinensis and Zanthoxylum ailanthoides were found in the fields in Taiwan during the investigation of diseases of medicinal herb plants from 2006 to 2012. Diseased plants of C. sinensis showed symptoms of browning on basal stems which were shrunken within a few days, and the plants were droopy. Severely infected plants were leaf yellowing, stunted and killed due to root rotting. Diseased plants of Z. ailanthoides showed symptoms of water-soaked lesions on leaves, buds and stems, which enlarged in size and turned dark brown quickly. Eventually, the infected leaves turned yellow and fell prematurely, and the buds and stems rotted and collapsed. Diseased plants also showed symptoms of basal stem rot and root rot. Two species of Phytophthora, including P. nicotianae (P. parasitica) (2 A^1 isolates) and P. palmivora (3 A^2 isolates) were isolated from C. sinensis and one species of Phytophthora (P. nicotianae, 7 A^1 and 4 A^2 isolates) was isolated from Z. ailanthoides. Results of pathogenicity tests by artificial inoculations showed that both P. nicotianae and P. palmivora were the pathogens of C. sinensis and P. nicotianae was the pathogen of Z. ailanthoides, with disease symptoms identical to the diseased plants observed in the fields. Each Phytophthora isolate was re-isolated from the infected tissues of the inoculated plants. All the isolates of Phytophthora obtained from C. sinensis and Z. ailanthoides belonged to the typical types of P. nicotianae or P. palmivora. The range of temperature for mycelial growth of P. nicotianae isolates were 8-36℃ with optimal temperature at 28℃, while the range for P. palmivora was 12-35℃ with optimal temperature at 28℃. Sporangia of P. nicotianae isolates were spherical or sub-spherical, unsymmetrical, with semi-spherical papilla, and non-deciduous, whereas sporangia of P. palmivora were spherical, ovoid or elliptical, symmetrical, with semispherical papilla, and deciduous with very short pedicels (< 5 μm). Both Phytophthora species produced chlamydospores on agar media. DNA sequences of the internal transcribed spacers (ITS1-5.8S rDNA-ITS2) region and the partial β-tubulin gene also support the morphological classification of P. nicotianae and P. palmivora. This is the first record of Phytophthora diseases of C. sinensis caused by P. nicotianae and P. palmivora and Z. ailanthoides caused by P. nicotianae in Taiwan and in the world. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。