title: Specific arbuscular mycorrhizal fungi associated with non-photosynthetic Petrosavia sakuraii (Petrosaviaceae).
abstract: Mycorrhizal fungi in roots of the achlorophyllous Petrosavia sakuraii (Petrosaviaceae) were identified by molecular methods. Habitats examined were plantations of the Japanese cypress Chamaecyparis obtusa in Honshu, an evergreen broad-leaved forest in Amami Island in Japan and a mixed deciduous and evergreen forest in China. Aseptate hyphal coils were observed in root cortical cells of P. sakuraii, suggesting Paris-type arbuscular mycorrhiza (AM). Furthermore, hyphal coils that had degenerated to amorphous clumps were found in various layers of the root cortex. Despite extensive sampling of P. sakuraii from various sites in Japan and China, most of the obtained AM fungal sequences of the nuclear small subunit ribosomal RNA gene were nearly identical and phylogenetic analysis revealed that they formed a single clade in the Glomus group A lineage. This suggests that the symbiotic relationship is highly specific. AM fungi of P. sakuraii were phylogenetically different from those previously detected in the roots of some mycoheterotrophic plants. In a habitat in C. obtusa plantation, approximately half of the AM fungi detected in roots of C. obtusa surrounding P. sakuraii belonged to the same clade as that of P. sakuraii. This indicates that particular AM fungi are selected by P. sakuraii from diverse indigenous AM fungi. The same AM fungi can colonize both plant species, and photosynthates of C. obtusa may be supplied to P. sakuraii through a shared AM fungal mycelial network. Although C. obtusa plantations are widely distributed throughout Japan, P. petrosavia is a rare plant species, probably because of its high specificity towards particular AM fungi.
authors.affiliation: Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan. m_yamato@muses.tottori-u.ac.jp.
authors.forename: Masahide
authors.initials: M
authors.lastname: Yamato
authors.affiliation: Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yagame
authors.affiliation: Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Shimomura
authors.affiliation: Fungus/Mushroom Resource and Research Center, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, 680-8553, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Iwase
authors.affiliation: Department of Biology, Faculty of Education, Gifu University, Gifu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Ogura-Tsujita
authors.affiliation: Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Yukawa
mesh_terms: D002681:China; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D055137:Glomeromycota / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D007564:Japan; D019684:Magnoliopsida / Q000382:microbiology* / Q000502:physiology; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D012331:RNA, Fungal / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D012331:RNA, Fungal; D012337:RNA, Ribosomal, 18S