Phylogenetic Placement and Host Specificity of Mycorrhizal Isolates Belonging to AG-6 and AG-12 in the Rhizoctonia solani Species Complex

Pope, Elizabeth J.; Carter, Dee

doi:10.2307/3761825

Cited by 34 publications

(12 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bootstrap support was calculated using MP and Neighbor-Joining (NJ) analysis. Thanatephorus cucumeris (GenBank AF153778 from soybean in Japan; Pope and Carter, 2001) was used as the outgroup for the fungal sequences (Otero et al, 2002(Otero et al, , 2004.…”

Section: Methodsmentioning

confidence: 99%

Widespread mycorrhizal specificity correlates to mycorrhizal function in the neotropical, epiphytic orchid Ionopsis utricularioides (Orchidaceae)

Otero

Flanagan²,

Herre³

et al. 2007

American J of Botany

118

View full text Add to dashboard Cite

Tropical orchids constitute the greater part of orchid diversity, but little is known about their obligate mycorrhizal relationships. The specificity of these interactions and associated fungal distributions could influence orchid distributions and diversity. We investigated the mycorrhizal specificity of the tropical epiphytic orchid Ionopsis utricularioides across an extensive geographical range. DNA ITS sequence variation was surveyed in both plants and mycorrhizal fungi. Phylogeographic relationships were estimated for the mycorrhizal fungi. Orchid functional outcomes were determined through in vitro seed germination and seedling growth with a broad phylogenetic representation of fungi. Most fungal isolates derived from one clade of Ceratobasidium (anamorphs assignable to Ceratorhiza), with 78% within a narrower phylogenetic group, clade B. No correlation was found between the distributions of orchid and fungal genotypes. All fungal isolates significantly enhanced seed germination, while fungi in clade B significantly enhanced seedling growth. These results show that I. utricularioides associates with a phylogenetically narrow, effective fungal clade over a broad distribution. This preference for a widespread mycorrhizae may partly explain the ample distribution and abundance of I. utricularioides and contrasts with local mycorrhizal diversification seen in some nonphotosynthetic orchids. Enhanced orchid function with a particular fungal subclade suggests mycorrhizal specificity can increase orchid fitness.

show abstract

Section: Methodsmentioning

confidence: 99%

Widespread mycorrhizal specificity correlates to mycorrhizal function in the neotropical, epiphytic orchid Ionopsis utricularioides (Orchidaceae)

Otero

Flanagan²,

Herre³

et al. 2007

American J of Botany

118

View full text Add to dashboard Cite

show abstract

“…On the other hand, studies based on the AFLP technique, scarcely employed in Rhizoctonia, were based on several aspects related to factors and genes involved in sexual compatibility mechanisms of R. solani (Julián et al, 1999) or investigating genetic diversity of some R. solani AG (Ceresini et al, 2002). Sequencing of ribosomal DNA has been widely employed in the complex during recent years, to reconstruct phylogenetic relationships between the different organisms of the form genus (Boysen et al, 1996;Kuninaga et al, 1997;Roberts, 1999;Salazar et al, 1999Salazar et al, , 2000González et al, 2001González et al, , 2002Pope and Carter, 2001;Shan et al, 2002) or less frequently other regions such as beta-tubuline (González et al, 2003). In the future, molecular approaches should include the sequencing of a broader range of DNA regions (e.g.…”

Section: Molecular Approaches To Study the Form Genusmentioning

confidence: 99%

Review. Biology and systematics of the form genus Rhizoctonia

García¹,

Onco

Susan

2006

Span. j. agric. res.

202

View full text Add to dashboard Cite

Members of the form genus Rhizoctonia D.C. are considered as a complex mixture of filamentous fungi, having in common the possession of a non-spored imperfect state, usually referred to as the Rhizoctonia anamorph. The group includes several of the most devastating crop pathogens like Thanatephorus cucumeris (Frank) Donk (anamorph = Rhizoctonia solani Kühn), the majority of orchid mycorrhizal symbionts (mainly belonging to genus Ceratobasidium D.P. Rogers) and a collection of saprotrophic organisms of different systematic placement. The Rhizoctonia anamorph is characterized by several common features present among members of the entire Rhizoctonia species complex. Taxa from the group have been rearranged into several groups of higher fungi, including both Ascomycota and Basidiomycota, and split into several genera, employing criteria such as the analysis and ultrastructural comparison of septal apparatus. Until very recently, classification for some of the groups within the complex has been exclusively based on criteria such as hyphal anastomosis, since other types of diagnostic features are usually scarce in these fungi. Phytopathological studies in the complex have represented the major contingent of contributions in the group, especially in the case of R. solani. Some members of the complex have been reported to be protective isolates against pathogenic members of Rhizoctonia and some other fungal pathogens. This review focuses on the knowledge of several aspects of the species of Rhizcotonia s. lato, such as its current taxonomic placement, the biology and systematics of some groups of the complex, and a revision of the methodologies employed in studying it.Additional key words: Basidiomycetes, biocontrol, Ceratobasidiaceae, Ceratobasidium, fungal diseases, methodology, taxonomy, Thanatephorus. Resumen Biología y Sistemática del género forma RhizoctoniaLos miembros del género forma Rhizoctonia D.C. son considerados como un complejo de hongos filamentosos, presentando en común una fase asexual no productora de esporas, denominada anamorfo tipo Rhizoctonia. El grupo incluye algunos importantes patógenos como Thanatephorus cucumeris (Frank) Donk (anamorfo=Rhizoctonia solani Kühn), la mayoría de especies micorrícicas de orquídeas (principalmente del género Ceratobasidium D.P. Rogers), y algunos taxones de posición taxonómica variada. El anamorfo tipo Rhizoctonia es definido por una serie de características, presentes y comunes en todos los taxones del complejo. Los taxones del grupo han sido distribuidos entre varios grupos de hongos, incluyendo Ascomicetes y Basidiomicetes, y reubicados en varios géneros de ambas clases, empleando criterios de clasificación tales como el análisis y comparación de la ultraestructura del aparato septal. Habitualmente, la clasificación en algunos de los grupos del complejo ha estado basada en la aplicación de criterios tales como la anastomosis hifal, debido a que en este tipo de hongos es escasa la presencia de un número aceptable de caracteres diagnósticos. Los trabajos ...

show abstract

“…AG-6: HG-I, GV (Mazzola, 1997;Meyer et al, 1998;Carling et al, 1999;Pope and Carter, 2001;Naito, 2004) Symptom: root rot, crater rot, and symbiosis (orchids).…”

Section: Wwwintechopencommentioning

confidence: 99%