Identification of Armillaria species associated with Polyporus umbellatus using ITS sequences of nuclear ribosomal DNA

Abstract

The sclerotia of Polyporus umbellatus were collected from three locations in Japan and three locations in China. All the collected sclerotia were adhered to by rhizomorphs of the symbionts. When the sclerotium of P. umbellatus was cross sectioned, the internal part of the sclerotium was cream colored, and many black regions surrounding the invading rhizomorphs were observed. The surrounding zone contained string-like, gelatinous masses composed of hyphae, and its outside was brown in color. All isolates were similar in colony morphology and grew well on PDA medium with well-developed rhizomorphs. All the isolates showed typical morphology of Armillaria. The isolated fungi were identified via the ITS region of the nuclear ribosomal DNA sequence. Phylogenetic analysis based on the neighbor-joining method showed that all the isolates clustered with fungi belonging to Armillaria species. Among them, five species (A. sinapina, A. calvescens, A. gallica, A. cepistipes, and A. nabsnona) and the symbiont formed a highly supported clade. We report on the case where Armillaria has a relationship in the sclerotium of Polyporus umbellatus.

Research Note Genetic diversity of endangered Polyporus umbellatus from China assessed using a sequence-related amplified polymorphism technique

“…The dendrogram tree of 8 natural Polyporus umbellatus strains collected from 7 provinces in China based on Jaccard similarity coefficients by using unweighted pair group method with arithmetic mean method from sequence-related amplified polymorphism markers. The numbers correspond to those listed in Table 1. several biological species in North America, Europe, Australia, Japan, and China (Kikuchi and Yamaji, 2010;Wang, 2010). Moreover, chuling associates with many Armillaria species in China and Japan (Kikuchi and Yamaji, 2010), although Xu et al (2003) have reported that Armillaria mellea can form the sclerotium of chuling.…”

“…The numbers correspond to those listed in Table 1. several biological species in North America, Europe, Australia, Japan, and China (Kikuchi and Yamaji, 2010;Wang, 2010). Moreover, chuling associates with many Armillaria species in China and Japan (Kikuchi and Yamaji, 2010), although Xu et al (2003) have reported that Armillaria mellea can form the sclerotium of chuling. Therefore, different environments may affect the composition of Armillaria species populations, which would form selection pressure on the genetic structure of local chuling strains.…”

Determination of optimal carbon source and pH value for sclerotial formation of Polyporus umbellatus under artificial conditions

“…Normal mycelia can turn into sclerotia as a hardened mass of mycelia under environmental extremes of cold, drought and nutritional depletion (Liu and Guo 2010). Guo and Xu (1992) elucidated that, in wild conditions, sclerotia of P. umbellatus cannot grow or produce new sclerotia without Armillaria mellea, which has a strong and special symbiotic relationship with P. umbellatus Xu 1992, 1993;Xu et al 2003;Kikuchi and Yamaji 2010). A. mellea can provide sclerotia of P. umbellatus with nutrients after the subtle symbiosis between the two fungi has formed (Guo and Xu 1991).…”

Genetic diversity of Armillaria spp. symbiotic with Polyporus umbellatus in China

“…Attempts have been made to identify the Armillaria species that are associated with P. umbellatus in Japan (Kikuchi and Yamaji, 2010). To date, very limited information is available on phylogenetic relationship and genetic diversity in Armillaria species associated with P. umbellatus around China.…”

“…Fries belongs to a genus of Polyporaceae and, has been considered to be a species of woodrotting fungi (Kikuchi and Yamaji, 2010). P. umbellatus sclerotia is widely distributed in both broad-leaved and coniferous forests in Asia, Europe and temperate regions of the Northern Hemisphere (Zhao et al, 2010).…”