臺灣臺北及宜蘭地區褐根病菌之遺傳變異分析

Genetic diversity of Phellinus noxius from Taipei and Yilan of Taiwan

黃郁晴(Yu-Ching Huang) ； 張東柱(Tun-Tschu Chang) ； 鍾嘉綾(Chia-Lin Chung) ； 劉瑞芬(Ruey-Fen Liou)

《植物病理學會刊》 24卷2期 (2015/06) Pp. 77-88

https://doi.org/10.6649/PPB.201506_24(2).0001

摘要

褐根病菌［Phellinus noxius（Corner）Cunningham］寄主範圍廣泛，可感染樟樹、榕樹、臺灣欒樹、鳳凰木等多種樹木，是近年來備受重視的病原菌。植物罹患褐根病時，初期病徵不明顯，及至後期常因根部木材腐朽，養分和水分的運輸功能嚴重受損，以致萎凋、死亡或風倒，不僅破壞景觀，更可能造成公共危險。為探討褐根病菌遺傳變異及可能的傳播方式，本研究開發ISSR（inter-simple sequence repeat）分子標誌，發現以9個ISSR引子可有效區分不同擔孢子菌株間的遺傳變異，同時亦可反映不同子實體來源的擔孢子菌株。以挑取單一節生孢子的方式繼代培養褐根病菌時，多數菌株之ISSR基因型在跨至少五個世代均顯穩定。此外，親緣樹分析發現，自臺北市和平高中和螢橋國中共28棵罹病樹木所分離的褐根病菌菌株分別屬於11個無性繁殖系，顯示這些區域並不存在顯著的優勢菌系，但自相鄰罹病樹所分離的菌株一般呈現較為近似的基因型。綜言之，本研究所開發的ISSR分子標誌可應用於探討褐根病菌的遺傳變異，不僅為褐根病藉由根接觸傳染的可能性提供初步分子證據，也揭示擔孢子作為潛在感染源的可能性。

關鍵字

簡單重複性序列區間 ； 無性繁殖系 ； 褐根病 ； 褐根病菌

並列摘要

Phellinus noxius (Corner) Cunningham causes brown root rot in a wide variety of tree species, including many plantation and landscape trees such as Cinnamomum camphora, Delonix regia, Ficus microcarpa, and Koelreuteria henryi. While infecting the trees, the pathogen not only disintegrates the bark and wood structure, but also seriously impairs nutrient transportation and water uptake, thereby causing disease symptoms such as branch dieback, yellowing and wilting of leaves, slow plant growth, and even plant death. Sometimes, the diseased trees may die within a few months of infection. Because of the severe loss it caused in Taiwan, P. noxius has attracted much attention in recent years. To analyze the genetic diversity of P. noxius, we developed a inter-simple sequence repeat (ISSR) genotyping platform based on 9 primers, with most of the ISSR banding patterns remain stable for at least five successive generations of single-arthrospore subcultures. Phylogenetic analysis of the ISSR genotypes indicated that P. noxius basidiospore isolates from a single basidiocarp form a cluster distinct from those originated from other basidiocarps. Moreover, 11 clonal lineages were identified for P. noxius isolates collected from 28 infected trees in two campuses of Taipei, which indicate the absence of any predominant virulent strain in these areas. Nonetheless, fungal isolates obtained from infected trees nearby each other tend to display similar genotypes. These results support dissemination of P. noxius through root contact and highlight the possibility of basidiospores as potential inoculum.

並列關鍵字

ISSR ； clonality ； brown root rot ； Phellinus noxius