臺灣荖葉與荖花疫病病原菌之鑑定

Identification of Phytophthora Species on Piper betle and P. longum in Taiwan

安寶貞 ； 黃德昌 ； 王姻婷

《植物病理學會刊》 11卷4期 (2002/12) Pp. 179-188

https://doi.org/10.6649/PPB.200212_11(4).0003

摘要

自1978年至1998年自荖花與荖葉栽培區分離疫病菌，其中1998年以前分離到的疫病菌均為Phytophthora parasitica，而1990年之後者均為Phytophthora capsici。調查時顯示，P. parasitica主要自罹病根系與主莖分得，罹病植株出現生長衰弱等慢性立枯現象，最後終至死亡，甚而全園癈耕。而P. capsici除自罹病之根系與主莖分得外，在雨季亦經自罹病葉片、花器與果實分得。本研究共分離到16株P. parasitica與39株P. capsici菌株，其中P. parasitica 為非標準型(atypical type)，均為A2配對型；而P. capsici均為A1配對型，且完全為標準型(typical type)。P. capsici菌株在V-8培養基上之菌落白色平滑，具不明顯的放射狀花紋；菌絲生長溫度10-36°C，最適24-32°C；在培養基上與水中會產生大量胞囊(sporangia)，每一胞囊梗上著生3-10個胞囊。胞囊橄欖形、倒洋梨形或橢圓形，具顯著乳突(semi-spherical papilla)；大部份胞囊具脫落性，胞囊柄(pedicels)長平均38.9μm。胞囊大小平均為56.5x40.4μm，胞囊長寬比平均為1.39。以分離到的P. capsici游走子懸浮液接種荖花扦插苗的根系與葉片，無論有無傷口，均可誘發病害，但有傷口時，發病較嚴重。接種葉片時出現的病徵與自然界發生者相同。自荖花分離的P. capsici對番椒具病原性，反之亦然，且兩者的菌絲蛋白質電泳圖譜幾乎完全一致。

關鍵字

荖花 ； 荖葉 ； 枸醬 ； 疫病 ； Phytophthora capsici ； Phytophthora parasitica

並列摘要

Species of Phytophthora in the fields of Piper betle and Piper longum in Taiwan were investigated from 1978 to 1996. Phytophthora parasitica was detected in all of the investigated fields before 1988, whereas only P. capsici, but not P. parasitica, was isolated from the diseased tissues of pipers in the fields from 1990-1996. According to investigations, P. parasitica was isolated from rhizosphere soil, diseased root and stem of the slow declining plants. The infected plants died eventually 3-5 years after appearance of declining symptoms. However, beside underground portions, P. capsici also attacked aboveground portions including leaves, stems and blossoms during rain. The fungus was most frequently isolated from these diseased tissues in wet season. A total of 16 isolates of P. parasitica were obtained in the early years. They all belonged to A2 mating type and were not typical type. All of the 39 isolates, which were obtained after 1990, were typical P. capsici belonging to A1 mating type. Colonies of P. capsici grown on V-8 agar were smooth with slightly radiate patterns. The minimum, maximum and optimum temperatures for mycelial growth were 10°C, 36°C and 24-32°C, respectively. Isolates of P. capsid produced large amount of sporangia on V-8 agar as well as in water. Each single sporangiophore bore 3 to 10 sporangia arranging like an umbrella. Papillate sporangia were ovoid, obperiform or subspherical, and mostly deciduous with pedicel about 38.9μm long in average. Chlamdspores were absent. Symptoms similar to those seen in the fields were observed when leaves and stems of cuttings of P. longum were inoculated with zoospore suspension of P. capsici obtained from P. betle and P. longum in pathogenicity tests. Wounding was not necessary for infection to take place but enhanced disease progress. The pathogen also caused root rot, wilt and death of the inoculated cuttings. P. capsici was reisolated from all artificially infected tissues. All tested isolates of P. capsici from P. betle and P. longum were pathogenic to sweet pepper and vice versa. Meanwhile, the SDS electrophoreic band patterns of mycelium protein of P. capsici from both hosts were almost identical.

並列關鍵字

Phytophthora capsici；typical type；Phytophthora parasitica；Piper betle；Piper longum