臺灣疫病菌基因型之研究(III)

疫病菌Phytophthora parasitica Dastur (=Phytophthora nicotianae Breda de Haan) 可 危害之寄主種類繁多，是本省非常重要的植物病原菌。研究顯示，從不同寄主分離到之 疫病菌在形態及生理特徵上都有相當差異，接種試驗也發現菌系間病原性有差別，寄主 範圍也不同，可能已有分化現象。本計畫試以疫病菌反轉位子，PARTN1，之局部序列 為遺傳標記進行疫病菌基因型分析，以便探討自不同寄主植物所分離到之疫病菌菌株基 因型的變異情形。對46 株疫病菌菌株進行基因組南方雜合分析的結果顯示，各菌株所 呈現之雜合圖譜變異性相當大，但以PARTN1 為核酸探針確實可以明確區分自煙草、萬 年青、或枇杷所分離到之疫病菌株；之前的研究也顯示這些菌株不論在病原性、型態、 或生理等特性都與典型疫病菌株有所差異。因此以反轉位子序列為探針進行基因型分析 確實可以反映出菌株間的類緣關係，至於其他供試菌株之雜合圖譜為何變化多端仍待進 一步深入研究。Phytophthora parasitica Dastur (= Phytophthora nicotianae Breda de Haan), being able to attack a wide variety of plants, is a very notorious plant pathogen in the central and southern Taiwan. It has been shown that there are variations in the morphology, pathogenicity, and virulence among P. parasitica isolated from different host species, indicating that differentiation may have arisen in P. parasitica isolated from different host species. The purpose of this study was to analyze the genotypes of P. parasitica by DNA fingerprinting, using reverse transcriptase sequence of PARTN1 as a genetic marker. PARTN1 is a copia-like retrotransposon identified in this fungus. A total of 46 P. parasitica isolates were analyzed. The results indicate that, although the hybridization patterns obtained for each isolate are highly polymorphic, PARTN1 can indeed distinguish P. parasitica isolated from (1) tobacco, (2) dieffenbachia, or (3) loquat, which are known as atypical P. parasitica. Thus, PARTN1 could be very useful in studies on the phylogenetics and population biology of P. parasitica