Fig 1 - uploaded by Alan R Wood
Content may be subject to copyright.
Pseudolagarobasidium acaciicola basidiome (b) growing around relatively large sand grains (s) and the base of an inoculated, now dead, Acacia cyclops seedling (Ac). From DAOM 232309. Scale bar = 2 mm.
Source publication
Acacia cyclops A. Cunn. ex G. Don (Fabaceae, Mimosoideae), originating from Western Australia, is a serious environmental weed in South Africa. A dieback disease of A. cyclops occurring in South Africa is described, and a fungus herein named Psuedolagarobasidium acaciicola Ginns sp.nov. (Basidiomycetes, Polyporales, Hyphodermataceae) was consistent...
Contexts in source publication
Context 1
... cylindrici vel applanati, 1–2.5 mm longis et 0.3–1.0 mm latae, leviter. Systema hypharum monomiticum. Hyphae fibulatae, saepe crassiuscula vel tenuitunicata, brun- neola, 2.0–3.5 m m latae. Cystidia numerata, tubularica vel clavata, tenuitunicata, versus basim plus minus dilatata, 20– 145 m m  5–10 m m. Basidia gracilis clavata, 16–34 m m  4–6 m m, cum 4 subulatis sterigmatis. Sporae ellipsoidea latae, tenuitunicatae et non cyanophilae, leves, (4.4–) 4.8–5.6 (–6.0) m m  3.0–3.6 m m, non amyloideae, non dextrinoi- deae. HOLOTYPUS: DAOM 232308, see details below. Basidiomes effuse, gregarious, each up to 3 cm in diameter, Avellaneous to Wood Brown, initially smooth, then developing erect (negatively geotrophic), 1–2.5 mm tall, cylindrical to raduloid aculei, some with two to three short apical branches, with pallid, minutely granulose apices. Margin pallid, up to 1 mm wide, thin, of fine, radiating fibers at 10  . Subiculum pallid, up to 240 m m thick. Not blackening in KOH. Hyphal system dimitic. Generative hyphae in the aculei parallel, 2.0–3.5 m m in diameter, clamp connections com- mon, branches infrequent to common and often arising from a clamp, the walls yellow-brown to brown, typically 0.5– 0.8 m m thick, non amyloid, non dextrinoid, some encrusted with roughened, angular to circular, hyaline, 4 m m diameter crystals. Hyphae of the subiculum essentially vertically ori- ented, 2.5–4.5 m m in diameter with clamp connections, the walls hyaline to yellow, mostly 0.5 m m thick, smooth, some densely encrusted with small, yellow granules. Margin com- posed of hyphae and gloeocystidia. The hyphae 2–4 m m in diameter with clamp connections, the walls hyaline, thin, smooth, some sparsely to densely encrusted with hyaline, angular, up to 6 m m  3 m m crystals or round to oblong, about 1 m m  2 m m diameter granules. Adjacent to substrate in infrequent small pockets are two types of interwoven hyphae (1.2–) 1.6–2.0 m m in diameter, some hyphae with clamp connections, many clamps are ansiform, the walls hyaline, thin, nonamyloid. Other hyphae are of the binding type, that is, microbinding hyphae (‘‘narrow (<3 m m in diameter), frequently branched, often at right angles, aseptate, thin- to thick-walled, nonstaining hyphae arising from generative hyphae’’ Nakasone (2001)), infrequently to rarely branched, branches relatively short and attenuated, aseptate, the walls hyaline, apparently thick. Gloeocystidia scattered throughout the hymenium and in the margins, clavate to cylindrical and slightly wavy, either narrowing to 3 m m in diameter over the basal third or basally swollen, 20–145 m m  5–10 m m, some projecting above the hymenial surface up to 15 m m, the walls hyaline, thin, smooth, nonamyloid, the contents slightly refractive, homogeneous, or in a formalin- preserved basidiome of small (0.4 m m in diameter) refractive granules, sulfo-negative, many dark blue in cotton blue, many dark pink in phloxine. Basidia slenderly clavate to clavate, some with a median constriction, 16–47 m m  5– 7 m m, mostly collapsed, the walls hyaline, thin, cyanophilous; four sterigmate, each slender, arced, 5 m m long. Basidiospores broadly ellipsoid, a few ovoid, (4.4–) 4.8–5.6 (–6.0) m m  (3.0–) 3.2–4.0 m m ( n = 25), the walls very thin, hyaline, smooth, nonamyloid, nondextrinoid, acyano- philous. ECOLOGY: The fungus was originally isolated in September 1995 from root segments of A. cyclops that had recently suc- cumbed to a dieback disease. Basidiomes developed on soil around the base of inoculated A. cyclops seedlings as soon as 1.5 months after inoculation (Fig. 1). HOLOTYPE: SOUTH AFRICA: Western Cape Province, Hermanus, Walker Bay Nature Reserve (34 8 26 ’ S, 19 8 19 ’ E), on leaf litter around the root crown of trees inoculated with culture DAOM 230979 on 5 August 1997, collected on 6 September 2000, Alan Wood s.n. (DAOM 232308). ADDITIONAL MATERIAL EXAMINED: SOUTH AFRICA: Western Cape Province : Stellenbosch, Vredenburg (ARC-Plant Protection Research Institute), on soil around seedlings in pots in greenhouse, inoculated with culture CBS 115545 on 4 March 1999, collected on 15 April 1999, AR Wood s.n. (DAOM 232309); sin loc. , on soil around seedlings in pots in greenhouse, inoculated with culture CBS 115542 on 21 May 2004, collected on 17 June 2004, AR Wood s.n. (PREM 58239); sin loc. , on soil around seedlings in pots in greenhouse, inoculated with culture CBS 115544 on 21 May 2004, collected on 17 June 2004, AR Wood s.n. (PREM 58240). GROWTH IN CULTURE: Mycelial growth rapid, covering the diameter of four of the eight replicate Petri dishes in 1 week, the remaining dishes covered when examined at 2 weeks. Advancing zone at 5 d even, raised 5 mm to the limit of growth, texture sparse cottony (Fig. 6). Mat white, sparse cottony floccose, raised 1–2 mm, growing up the sides of the dishes. Odor nil. Agar under the mat not discolored. At 5 weeks mat white, loosely woolly floccose or woolly, raised 1–2 mm over the younger half of the mat and sparse cottony, raised 5 mm over the half around the inoculum (Fig. 6). Odor nil. Agar under the mat unchanged on DAOM 230978 and tan on DAOM 230979. Advancing zone hyphae at 1 week essentially radially ori- ented, 2–7 m m in diameter with a single clamp connection at each septum, septa scattered (sometimes 350–550 m m between septa), branches infrequent, often arising opposite a clamp connection and more common on narrower hyphae. At 5 weeks, hyphae on surface of agar infrequently branched with clamp connections, 2–4 (–8) m m in diameter, the walls hyaline, thin, some segments heavily encrusted with 1–4 m m in diameter, angular granules. Also scattered fine binding hyphae, 2 m m in diameter, aseptate, apparently solid, rather frequently branched, with attenuated branches 15–30 m m long. Aerial hyphae infrequently branched with clamp connections (typically 50–70 m m between septa), 1.5–5.0 m m in diameter, the walls hyaline, up to 0.5 m m thick. Arthroconidia on aerial and surface mycelium, rectan- gular, oblong to broadly ellipsoid, 5–12 m m  2–5 m m, the walls hyaline, thin, smooth. Gloeocystidia common on surface mycelium in DAOM 230979, infrequent in DAOM 230978, terminal and intercalary, clavate, cylindrical or basally swollen and narrowing to an obtuse apex, 30–60 m m  6–16 m m, contents homogeneous in KOH, slightly refractive, the walls hyaline, thin, smooth. The two cultures studied of P . acaciicola , although similar in most features, differed in a few characters. In contrast with DAOM 230979, culture DAOM 230978 did not dis- color the agar, it produced fewer gloeocystidia as well as a denser mat at 5 weeks of growth and hyphae up to 8 m m in diameter (versus a maximum of 5 m m in DAOM 230979). ISOLATES STUDIED: SOUTH AFRICA: Western Cape Province : Knysna area, near Sedgefield, secondary beach dune above Swartvlei estuary (34 8 00 ’ S, 21 8 44 ’ E), root collected 9 October 1996, cultured on 23 October 1996, from wood next to dark stain, AR Wood s.n. (DAOM 230978); Stillbaai area, near Vermaaklikheid (34 8 16 ’ S, 21 8 02 ’ E), root collected 13 September 1995, cultured on 15 September 1995, from wood next to dark stain, AR Wood s.n. (DAOM 230979, CBS 115543, PPRI 7335). OTHER ISOLATES: SOUTH AFRICA: Western Cape Province : Stillbaai area, near Vermaaklikheid (34 8 16 ’ S, 21 8 02 ’ E), root collected 13 September 1995, cultured on 15 September 1995, from wood next to dark stain, AR Wood s.n. (CBS 115542, PPRI 7334); sin loc. , root collected on 13 October 1998, cultured on 16 October 1998, from wood next to dark stain, AR Wood s.n. (CBS 115545, PPRI 7337); Knysna area, near Sedgefield, secondary beach dune above Swartvlei estuary (34 8 00 ’ S, 21 8 44 ’ E), root collected on 9 October 1996, cultured on 23 October 1996, from wood next to dark stain, AR Wood s.n. (CBS 115544, PPRI 7336). The dieback disease of Acacia cyclops was first noted from the area between Mossel Bay and George in the Western Cape Province, South Africa. Isolations from material collected from the field trips have confirmed that the disease occurs from near Hermanus in the west to near Oesterbaai in the east. The disease is having a significant effect on populations of the weedy tree, especially in the area between Stillbaai and George. Its prevalence decreases the greater the distance from the original area where the disease was first noted. These observations indicate that the disease is in the process of spreading, and it is predicted that with time it will spread throughout the distribution of A. cyclops in South Africa. A ...
Context 2
... in the screening tests. Pathogenicity of one selected isolate from this screening was tested against young potted saplings of A. cyclops growing in a shade house. The saplings were approximately 35–75 cm in height with a stem diameter of approximately 4–7 mm at the base of the stem. They were inoculated by cutting a flap of bark 2 cm long near the base of the stem, placing two sorghum seeds inoculated with the fungus within the flap, and sealing the flap with parafilm. In a preliminary trial, 8 saplings were inoculated. In a second trial, 20 saplings were inoculated, and as a control an additional 20 saplings were treated in an identical manner, except that noninoculated sorghum seed was used. In the preliminary trial, half of the saplings that died were examined microscopically, and fungal isolations were made (in the same manner as detailed above) from the rest. In the second trial, fungal isolations were made from all saplings that died. For the microscopic examination, thin transverse sections of wood were cut, stained with Analine blue in lactophenol for 2 min, mounted in glycerol, and examined using a Zeis Axioskop light microscope. To determine whether isolates of this unidentified basidiomycete differed in pathogenicity, 11 isolates were grown on sorghum seeds and used to inoculate A. cyclops saplings (approximately 1.4 m tall, 7–9 mm in diameter) in the same manner as above. Five saplings per isolate were inoculated. As a control a further 5 saplings were treated in an identical manner, except that noninoculated sorghum seed was used. Trees of A. cyclops (3–18 cm in diameter at soil level) growing in the field were inoculated by drilling 10 mm diameter holes at approximately 6 cm spaces around the cir- cumference of each tree, and filling the holes with an isolate grown on sorghum seed as above. This was done at two sites in the Western Cape Province. At each site, 60 trees were inoculated, and as a control a further 30 trees were treated in an identical manner with noninoculated sorghum seed. In the section on taxonomy, the colors cited follow Ridgway (1912) and begin with a capital letter, e.g., Avellaneous. Microscopic features of the fruiting bodies were examined in mounts of 2% ( m / v ) aqueous potassium hydox- ide (KOH), Melzer’s reagent (Kirk et al. 2001), 0.05% ( m / v ) cotton blue in lactic acid, and sulfobenzaldehyde (Larsen and Burdsall 1976). Abbreviations for herbarium names, that is, the National Mycological Herbarium, Canada (DAOM) and the National Collection of Fungi, South Africa (PREM), follow Holmgren et al. (1990). To describe the cultural characteristics, four replications of isolates DAOM 230978 and DAOM 230979 were grown on 2% malt agar in 9 cm plastic Petri dishes incubated at 25 8 C in the dark. The inoculum was an agar block, up to 5 mm square, containing mycelium cut from the margin of a mycelial mat. One block was placed on the agar at the edge of each Petri dish with the mycelium against the agar. The dishes were examined periodically over a 6 week period. In the field, the first aboveground symptom observed in A. cyclops trees was a slight discoloration of the leaves (leaves are a lighter green than normal) associated with wilting of the leaves. At the same time, older leaves had a higher than normal senescence rate, leaving predominantly the leaves at the branch tips. Within weeks there was a rapid dieback of all the aboveground parts. The crown of the stems were killed before the wilting began to appear. On nonsymptomatic trees or trees with early signs of stress growing next to dead ones, a disease interface (dark lines) was sometimes observed when cutting through live roots. Later, a white mantle of mycelium incorporating sand grains covered the main roots of all dying and dead trees, masking any disease interfaces. These roots were degraded by a dry rot. A basidiomycete, tentatively identified as a Ganoderma species (M.J. Morris, personal communication), was consistently obtained from all roots with a white mantle (from the bark under the mantle, from the wood just below the bark, and from the wood at the centre of the roots). None of the 14 isolates tested caused mortality of the A. cyclops seedlings in the pathogenicity screening tests. All other isolates, with the exception outlined below, caused no or very low mortality in the pathogenicity screening tests (42 isolates in total were tested). Included in these were isolates of Cylindrocladium pauciramosum (11 isolates), and Fusarium spp. (5 isolates). However, isolates of a second basidiomycete, described as Pseudolagarobasidium acaciicola (below), were obtained, from where there was no white mantle covering the roots and where a dark disease interface occurred. This fungus proved to be highly pathogenic, consistently causing 100% mortality of the A. cyclops seedlings in the pathogenicity screening tests (11 isolates were tested). Purple basidiomes developed on the sand surface surrounding killed seedlings (Fig. 1). All 8 plants of the preliminary sapling pathogenicity trial died between 1 and 2 months after inoculation. Isolations were made from 4 of these plants, and the same basidiomycete was reisolated in all cases. The other 4 were observed microscopically. A dark disease interface was present in all 4 stems, extending up to 12 cm away from the site of inoculation. The fungus had completely colonized the entire diameter of the stem. Fungal hyphae were noted within the xylem vessels and ray cells, as well as within some intercel- lular spaces. The results of the second sapling pathogenicity trial were identical, all 20 plants died between 1 and 2 months after inoculation. The same basidiomycete was reisolated from all killed plants. None of the control plants had died after 3 months. Of 11 isolates of this basidiomycete tested on saplings, 9 isolates killed all inoculated saplings within 5 months of inoculation. Most saplings were killed within 3 months. The other two isolates killed 3 and 4 out of a total of 5 saplings. None of the control saplings died. Three years after inoculation of the field growing trees, 86% and 54% had died at the two sites, respectively, whereas none of the control trees had died. Mycelial mats up to 3 cm in diameter, Avellaneous to Wood Brown in color, developed on the surface of the sand and leaf litter around dead seedlings. Some small, blunt aculei or horizontally elongated teeth formed on some mats (Fig. 1). A hymenial layer containing basidia developed on the exterior of the teeth. Although the fungus was clearly a Hymenomycete, the generic affinities were not obvious. In attempting to identify the pathogen, the literature on corticioid fungi was searched, especially Talbot’s (1958) key to the Thelephoraceae s.l. recorded from South Africa, Cunningham’s (1963) key to the Thelephoraceae s.l. of Australia and New Zealand, Hjortstam et al. (1987) keys to the Corticiaceae of North Europe, and J ̈lich and Stalpers (1980) keys to the Corticiaceae of the temperate northern hemisphere. Although none clearly led to a species with features that matched our fungus or even to a suitable generic name, we concluded that the features of the fungus were most similar to those of the genus Pseudolagarobasidium J.C. Jang & T. Chen. The genus cur- rently comprises three species, that is, P. calcareum (Cooke & Massee) Wu, P. concentricum (Cooke & Ellis) Hjort., and P. subvinosus (Berk. & Br.) Wu (Stalpers and Stegehuis 2005). The features of the Acacia fungus, although similar to, are distinct from those of these species, and it is pro- posed as a new ...
Context 3
... a further 5 saplings were treated in an identical manner, except that noninoculated sorghum seed was used. Trees of A. cyclops (3–18 cm in diameter at soil level) growing in the field were inoculated by drilling 10 mm diameter holes at approximately 6 cm spaces around the cir- cumference of each tree, and filling the holes with an isolate grown on sorghum seed as above. This was done at two sites in the Western Cape Province. At each site, 60 trees were inoculated, and as a control a further 30 trees were treated in an identical manner with noninoculated sorghum seed. In the section on taxonomy, the colors cited follow Ridgway (1912) and begin with a capital letter, e.g., Avellaneous. Microscopic features of the fruiting bodies were examined in mounts of 2% ( m / v ) aqueous potassium hydox- ide (KOH), Melzer’s reagent (Kirk et al. 2001), 0.05% ( m / v ) cotton blue in lactic acid, and sulfobenzaldehyde (Larsen and Burdsall 1976). Abbreviations for herbarium names, that is, the National Mycological Herbarium, Canada (DAOM) and the National Collection of Fungi, South Africa (PREM), follow Holmgren et al. (1990). To describe the cultural characteristics, four replications of isolates DAOM 230978 and DAOM 230979 were grown on 2% malt agar in 9 cm plastic Petri dishes incubated at 25 8 C in the dark. The inoculum was an agar block, up to 5 mm square, containing mycelium cut from the margin of a mycelial mat. One block was placed on the agar at the edge of each Petri dish with the mycelium against the agar. The dishes were examined periodically over a 6 week period. In the field, the first aboveground symptom observed in A. cyclops trees was a slight discoloration of the leaves (leaves are a lighter green than normal) associated with wilting of the leaves. At the same time, older leaves had a higher than normal senescence rate, leaving predominantly the leaves at the branch tips. Within weeks there was a rapid dieback of all the aboveground parts. The crown of the stems were killed before the wilting began to appear. On nonsymptomatic trees or trees with early signs of stress growing next to dead ones, a disease interface (dark lines) was sometimes observed when cutting through live roots. Later, a white mantle of mycelium incorporating sand grains covered the main roots of all dying and dead trees, masking any disease interfaces. These roots were degraded by a dry rot. A basidiomycete, tentatively identified as a Ganoderma species (M.J. Morris, personal communication), was consistently obtained from all roots with a white mantle (from the bark under the mantle, from the wood just below the bark, and from the wood at the centre of the roots). None of the 14 isolates tested caused mortality of the A. cyclops seedlings in the pathogenicity screening tests. All other isolates, with the exception outlined below, caused no or very low mortality in the pathogenicity screening tests (42 isolates in total were tested). Included in these were isolates of Cylindrocladium pauciramosum (11 isolates), and Fusarium spp. (5 isolates). However, isolates of a second basidiomycete, described as Pseudolagarobasidium acaciicola (below), were obtained, from where there was no white mantle covering the roots and where a dark disease interface occurred. This fungus proved to be highly pathogenic, consistently causing 100% mortality of the A. cyclops seedlings in the pathogenicity screening tests (11 isolates were tested). Purple basidiomes developed on the sand surface surrounding killed seedlings (Fig. 1). All 8 plants of the preliminary sapling pathogenicity trial died between 1 and 2 months after inoculation. Isolations were made from 4 of these plants, and the same basidiomycete was reisolated in all cases. The other 4 were observed microscopically. A dark disease interface was present in all 4 stems, extending up to 12 cm away from the site of inoculation. The fungus had completely colonized the entire diameter of the stem. Fungal hyphae were noted within the xylem vessels and ray cells, as well as within some intercel- lular spaces. The results of the second sapling pathogenicity trial were identical, all 20 plants died between 1 and 2 months after inoculation. The same basidiomycete was reisolated from all killed plants. None of the control plants had died after 3 months. Of 11 isolates of this basidiomycete tested on saplings, 9 isolates killed all inoculated saplings within 5 months of inoculation. Most saplings were killed within 3 months. The other two isolates killed 3 and 4 out of a total of 5 saplings. None of the control saplings died. Three years after inoculation of the field growing trees, 86% and 54% had died at the two sites, respectively, whereas none of the control trees had died. Mycelial mats up to 3 cm in diameter, Avellaneous to Wood Brown in color, developed on the surface of the sand and leaf litter around dead seedlings. Some small, blunt aculei or horizontally elongated teeth formed on some mats (Fig. 1). A hymenial layer containing basidia developed on the exterior of the teeth. Although the fungus was clearly a Hymenomycete, the generic affinities were not obvious. In attempting to identify the pathogen, the literature on corticioid fungi was searched, especially Talbot’s (1958) key to the Thelephoraceae s.l. recorded from South Africa, Cunningham’s (1963) key to the Thelephoraceae s.l. of Australia and New Zealand, Hjortstam et al. (1987) keys to the Corticiaceae of North Europe, and J ̈lich and Stalpers (1980) keys to the Corticiaceae of the temperate northern hemisphere. Although none clearly led to a species with features that matched our fungus or even to a suitable generic name, we concluded that the features of the fungus were most similar to those of the genus Pseudolagarobasidium J.C. Jang & T. Chen. The genus cur- rently comprises three species, that is, P. calcareum (Cooke & Massee) Wu, P. concentricum (Cooke & Ellis) Hjort., and P. subvinosus (Berk. & Br.) Wu (Stalpers and Stegehuis 2005). The features of the Acacia fungus, although similar to, are distinct from those of these species, and it is pro- posed as a new ...
Citations
... However, more recent studies including molecular data showed that these represent two different lineages (Hallenberg et al. 2008). Furthermore, morphologically, Radulodon presents more agglutinated hyphae, a bipolar mating system and astatocoenocytic nuclear behavior, while in Pseudolagarobasidium the hyphae are not agglutinated and its species are tetrapolar and heterocytic (Wood & Ginns 2006). ...
... Radulodon and Irpiciporus present bipolar species with astatocoenocytic nuclear behavior. Spongipellis delectans and S. unicolor are characterized by a tetrapolar mating system and astatocoenocytic nuclear behavior (Wood & Ginns 2006, Rajchenberg 2011. This data shows the importance of biological characteristics of the species and genera to better understand their evolution and phylogenetic relationships. ...
In this study, Pseudolagarobasidium pallens sp. nov. is proposed based on morphological and phylogenetic studies. Specimens were collected in Brazil and used for DNA sequence analyses of the internal transcribed spacer and the large subunit of the nuclear ribosomal RNA gene. The basidiomes of P. pallens are characterized by a pale cream coloration when fresh, hydnoid hymenophore with long teeth and thin whitish context. Microscopically, it differs from other related species by the larger basidiospores (4.6–)4.9–6.4(–6.8) × 3.2–4.5 µm. Phylogenetically, it is closely related to P. belizense. We also provide sequences of the Brazilian species Cerrena cystidiata for the first time and confirm that is closely related to the generic type C. unicolor. A taxonomic key to all species currently accepted in Pseudolagarobasidium and a brief discussion on the family Cerrenaceae as well as a comparison table of all its genera are also presented.
... Pseudolagarobasidium acaciicola was originally isolated from dead and dying A. cyclops trees (Wood & Ginns 2006). During 2012 and 2013, a survey was conducted of indigenous woody plants occurring within a three-metre radius of the stem of 100 recently dead or dying A. cyclops trees. ...
The use of plant pathogens for biological control (biocontrol) of invasive alien plants in South Africa was reviewed in 1991, 1999 and 2011. In this review, subsequent progress and projects undertaken in the years 2011 to 2020, on both classical agents using exotic pathogens and inundative agents using indigenous pathogens, are detailed. We report on the impact of several previously introduced exotic fungi, monitored during this period. A significant highlight is the completion of 30 years of annual monitoring, from 1991 until 2020, of the impact of Uromycladium morrisii Doungsa-ard, McTaggart, Geering & RG Shivas (Raveneliaceae) on the density of Acacia saligna (Labill.) Wendel (Fabaceae), with declines of up to 98% recorded at monitored sites. Post-release monitoring also suggested that Entyloma ageratinae R.W. Barreto & H.C. Evans (Entylomataceae), introduced when Ageratina riparia (Regel) R.M.King & H.Rob (Asteraceae) still had a very limited invaded range in South Africa, has prevented the weed from realizing its potential as an invader. Uromycladium woodii Doungsa-ard, McTaggart, Geering & R.G. Shivas (Raveneliaceae) has been established on Paraserianthes lophantha (Willd.) I.C.Nielsen (Fabaceae), as has Puccinia xanthii Schwein (Pucciniaceae) on Parthenium hysterophorus L. (Asteraceae). Prospodium transformans (Ellis & Everh.) Cummins (Raveneliaceae) failed to establish on Tecoma stans (L.) Juss ex Kunth var. stans (Bignoniaceae), while efforts to release Puccinia lantanae Farl. (Pucciniaceae) on Lantana camara L. (Verbenaceae) are underway. Of the established exotic pathogens that are classical biocontrol agents, two are considered to cause extensive damage, two considerable damage, and two moderate damage, to their target weeds. Puccinia arechavaletae Speg. (Pucciniaceae), an adventive fungus that is established on Cardiospermum grandiflorum Sw. (Sapindaceae) following an unknown path of introduction, is proving to be a damaging agent and the implications of its presence in the country are discussed. Early season augmentation of Puccinia eupatorii Dietel (Pucciniaceae) on Campuloclinium macrocephalum (Less.) DC. (Asteraceae) was tested to determine whether damage could be increased, but no difference in the rust's incidence and severity was evident between augmented and naturally infected plants at the end of the growth season. The identity of the indigenous fungus registered as Stumpout, for the control of coppice growth after felling of Acacia mearnsii De Wild. (Fabaceae), was confirmed as Cylindrobasidium torrendii (Bres.) Hjortstam (Physalacriaceae) rather than C. laeve (Pers.: Fr.) Chamuris, as previously thought. The application of another indigenous fungus, Colletotrichum acutatum J.H. Simmonds (Glomerellaceae), by means of helicopter flights has facilitated its establishment on Hakea sericea Schrad. & J.C. Wendl (Proteaceae), in inaccessible mountainous terrain. For registration purposes, toxicity testing (oral rat LD50) of these indigenous fungi are required. Lethal doses of Cylindrobasidium torrendii, C. acutatum and Pseudolagarobasidium acaciicola Ginns (Phanerochaetaceae), the latter for use against Acacia cyclops G. Don. (Fabaceae), exceeded 2000 mg kg1 body weight and all three fungi are thus considered safe for application.
... Two species have been reported from China: P. pronum and P. subvinosum. (Jang & Chen 1985;Wood & Ginns 2006;Nakasone & Lindner 2012;Nakasone 2015). ...
A new species, Pseudolagarobasidium baiyunshanense, is described and illustrated based on morphological characters and molecular evidences. It is characterized by subcretaceous, odontioid to raduloid, white, grayish violet when fresh, cream, olivaceous buff when dry basidioma (at first deep olive in KOH then fading), short aculei (up to 1.8 mm long), monomitic hyphal system with clamped generative hyphae, ellipsoid to broadly ellipsoid basidiospores (4–6.1 × 2.9–3.9 µm). Phylogenetic analysis based on ITS+nLSU rRNA gene regions supported P. baiyunshanense as a distinctive species belonging to Pseudolagarobasidium.
... New species of Gasteromycetes were described, such as Bovista acocksii De Villiers, Eicker & Van der Westhuizen ), but limited information is still available for the Geasteraceae of South Africa (Coetzee and Van Wyk 2003). A new basidiomycetous species, namely Pseudolagarobasidium acaciicola Ginns, was considered to be a potential biocontrol against the invasive weed Acacia cyclops (Wood and Ginns 2006;Kotzé et al. 2015). ...
Macrofungi are considered as organisms that form large fruiting bodies above or below the ground that are visible without the aid of a microscope. These fungi include most basidiomycetes and a small number of ascomycetes. Macrofungi have different ecological roles and uses, where some are edible, medicinal, poisonous, decomposers, saprotrophs, predators and pathogens, and they are often used for innovative biotechnological, medicinal and ecological applications. However, comprehensive checklists, and compilations on the diversity and distribution of mushrooms are lacking for South Africa, which makes regulation, conservation and inclusion in national biodiversity initiatives difficult. In this review, we compiled a checklist of macrofungi for the first time (excluding lichens). Data were compiled based on available literature in journals, books and fungorium records from the National Collection of Fungi. Even if the list is not complete due to numerous unreported species present in South Africa, it still represents an overview of the current knowledge of the macromycetes of South Africa. The list of names enables the assessment of gaps in collections and knowledge on the fungal biodiversity of South Africa, and downstream applications such as defining residency status of species. It provides a foundation for new names to be added in future towards developing a list that will be as complete as possible, and that can be used by a wide audience including scientists, authorities and the public.
... Based on these morphological characteristics, the fungus isolates were identified as a 45 member of Pseudolagarobasidium sp. (Wood R and Ginns J, 2006). ...
... At present, dieback is the major limiting factor to the spread of parkinsonia in northern Australia (Steinrucken et al. 2017b;van Klinken et al. 2009). There are indications that fungi associated with dieback can be potentially utilized as biocontrol agents and incorporated into the management strategy of such invasive woody weeds (Galea and Goulter 2013;Wapshere et al. 1989;Wood and Ginns 2006). We therefore investigated whether dieback symptoms could be replicated on healthy prickly acacia plants using the fungi sourced from the previously observed natural dieback event. ...
Prickly acacia (Vachellia nilotica subsp. indica, Family: Fabaceae) is an invasive woody weed in coastal and semi-arid rangelands of Australia. A prominent dieback event was observed on this species in 2010 in north-western Queensland. A Botryosphaeriaceae fungus, Cophinforma sp., was consistently isolated from symptomatic stem tissues. In preliminary studies, Cophinforma sp. and an isolate of Lasiodiplodia pseudotheobromae sourced from dieback-affected Parkinsonia aculeata (Family: Fabaceae) were found to be pathogenic to prickly acacia seedlings and juveniles. In this study, we investigated whether typical dieback symptoms could be replicated under glasshouse conditions and in the field following stem inoculations of these two fungi (either singly or in combination). In the glasshouse trial, stem lesions and leaf mortality were observed following stem inoculation by both of the test fungi although it was greatest in the presence of L. pseudotheobromae. However, no effects on plant growth or mortality were observed. In the field trials (located in central and north-western Queensland) both test fungi caused infection, but significant lesions were only induced by L. pseudotheobromae in central Queensland, and no treatment effects on plant growth or survival were observed at either site over the next two years. Prominent decline in plant vigour was observed in north-western Queensland two years after inoculation, but was presumed to be naturally occurring as it affected controls and neighbouring untreated plants equally. The test fungi were reisolated from lesions in both field and glasshouse trials, but were never found in adjacent tissue, suggesting that infection was successfully contained by the plant’s wound response. We found no potential for the tested fungal isolates to be effective biocontrol agents, although future studies should aim to initiate systemic infections.
... During the course of the last four decades, A. cyclops trees have been dying along the coastal planes in the Eastern and Western Cape Provinces of South Africa, particularly between the towns of George and Stilbaai (Taylor 1969;Wood and Ginns 2006;Kotzé et al. 2015). The dying trees suffer from a rapidly developing root and butt-rot disease that results in die-back, wilt, and a white rot of the affected roots and root collars. ...
... The dying trees suffer from a rapidly developing root and butt-rot disease that results in die-back, wilt, and a white rot of the affected roots and root collars. The disease has been attributed to the basidiomycete root-rot fungus Pseudolagarobasidium acaciicola Ginns (Wood and Ginns 2006;Kotzé et al. 2015). However, basidiomes of another fungus resembling a species of Ganoderma are also regularly seen attached to the bases of the dying trees. ...
... However, basidiomes of another fungus resembling a species of Ganoderma are also regularly seen attached to the bases of the dying trees. No attempt has been made to determine the identity of that fungus (Taylor 1969;Wood and Ginns 2006). ...
Large numbers of Acacia cyclops trees are dying along the coastal plains of the Eastern and Western Cape Provinces of South Africa. The cause of the deaths has been attributed to a root and butt rot disease caused by the basidiomycete fungus Pseudolagarobasidium acaciicola. However, many signs (e.g. basidiomes) and symptoms reminiscent of Ganoderma root-rot are commonly associated with the dying trees. In this study, isolates collected from basidiomes resembling species of Ganoderma, as well as from root and butt samples from diseased A. cyclops trees were subjected to DNA sequencing and morphological studies to facilitate their identification. Multi-locus phylogenetic analyses and morphological characterisation revealed that three species of Ganoderma are associated with dying A. cyclops trees. These included G. destructans, a recently described species causing root-rot on trees elsewhere in South Africa. The remaining two were novel species, one of which is described here as G. dunense. The novel species is distinguished by its mucronate basidiomes, laccate shiny pileus surface, duplex context and ovoid basidiospores. Only an immature specimen was available for the second species and a name was consequently not provided for it. Interestingly, only a single isolate representing P. acaciicola was recovered in this study, suggesting that further investigations are needed to ascertain the role of each of the four basidiomycetous root-rot fungi in the death of A. cyclops trees.
... Chamuris which is used to prevent coppicing of felled Acacia mearnsii trees (Morris et al. 1999). Another is under development, Pseudolagarobasidium acaciicola Ginns, which causes a dieback disease of Acacia cyclops G. Don (Kotze, Wood & Lennox 2015;Wood & Ginns 2006). More could be developed. ...
Background: Fungi are a major component of the functioning of all terrestrial ecosystems. Objectives: To increase awareness of fungi as drivers of ecosystem processes, including invasion biology.
Method: Here, I reviewed the information available regarding fungal invasions of native ecosystems in South Africa in the context of the National Status Report on Biological Invasions.
Results: Only seven fungal species are regulated as invaders (all category 1b) under the National Environmental Management: Biodiversity Act (NEM:BA) A&IS regulations. Four of these species are not yet known to occur in South Africa. Similarly, under the NEM:BA A&IS regulations, two of the four species listed as prohibited (i.e. not present in the country but which would pose a threat if introduced) are already present in the country. The actual number of alien fungi in South Africa is much greater. A preliminary listing of alien fungal species is made, with a total of 9 pathogenic species known to attack indigenous plants, 11 saprotrophic species, 1 fish pathogen, 23 host-specific pathogens of listed alien terrestrial plants, 61 ectomycorrhizal species and 7 host-specific pathogens deliberately introduced as biological control agents. The majority of fungal species were introduced to South Africa most likely via the introduction of crop plants as passengers, although there are as yet very little details available on pathways of introduction into South Africa.
Conclusion: For almost all aspects considered, it is concluded that there is simply not sufficient data to begin to understand the role and impact of fungal invasions in South Africa.
... For acacia plantations, the native fungus Ceratocystis albifundus causes a serious canker and wilt disease (Roux et al., 2007;Wingfield et al., 2011), while also killing native Fabaceae species such as Senegalia caffra (Roux et al., 2007). The native fungus Pseudolagarobasidium acaciicola is suggested to be an opportunistic pathogen to various native Fabaceae (Kotzé et al., 2015), and has subsequently been proposed as a possible mycoherbicide for invasive Acacia cyclops (Wood and Ginns 2006;Kotzé et al., 2015). Pines in South Africa have been devoid of pathogen attack by relatively host-specific organisms after many centuries of plantings. ...
... The use of native pathogens in biological control of invasive trees is an interesting prospect. For example, the native fungus Pseudolagarobasidium acaciicola has been proposed as a potential mycoherbicide for the invasive tree Acacia cyclops in South Africa (Wood and Ginns 2006;Kotzé et al., 2015). Similarly, the native pathogen Colletotrichum acutatum was suggested and is used as a mycoherbicide for the non-native and invading shrub Hakea sericea (Gordon and Fourie 2011). ...
Non-native trees have become dominant components of many landscapes, including urban ecosystems, commercial forestry plantations, fruit orchards, and as invasives in natural ecosystems. Often, these trees have been separated from their natural enemies (i.e. insects and pathogens) leading to ecological disequilibrium, that is, the immediate breakdown of historically co-evolved interactions once introduced into novel environments. Long-established, non-native tree plantations provide useful experiments to explore the dimensions of such ecological disequilibria. We quantify the status quo of non-native insect pests and pathogens catching up with their tree hosts (planted Acacia, Eucalyptus and Pinus species) in South Africa, and examine which native South African enemy species utilise these trees as hosts. Interestingly, pines, with no confamilial relatives in South Africa and the longest residence time (almost two centuries), have acquired only one highly polyphagous native pathogen. This is in contrast to acacias and eucalypts, both with many native and confamilial relatives in South Africa that have acquired more native pathogens. These patterns support the known role of phylogenetic relatedness of non-native and native floras in influencing the likelihood of pathogen shifts between them. This relationship, however, does not seem to hold for native insects. Native insects appear far more likely to expand their feeding habits onto non-native tree hosts than are native pathogens, although they are generally less damaging. The ecological disequilibrium conditions of non-native trees are deeply rooted in the eco-evolutionary experience of the host plant, co-evolved natural enemies, and native organisms from the introduced range. We should expect considerable spatial and temporal variation in ecological disequilibrium conditions among non-native taxa, which can be significantly influenced by biosecurity and management practices.
... By the early 1980s dead and dying A. cyclops were a common occurrence, especially between George and Still Bay in the Western Cape. The disease has spread over most of the distribution area of A. cyclops in South Africa (Wood and Ginns, 2006). The causative agent, Pseudolagarobasidium acaciicola Ginns (Polyporales, Basidiomycota) was isolated from A. cyclops roots (Wood and Ginns, 2006). ...
... The disease has spread over most of the distribution area of A. cyclops in South Africa (Wood and Ginns, 2006). The causative agent, Pseudolagarobasidium acaciicola Ginns (Polyporales, Basidiomycota) was isolated from A. cyclops roots (Wood and Ginns, 2006). P. acaciicola is difficult to isolate due to secondary fungi taking over the root system by the time the tree begins to die-back. ...
... This suggests that P. acaciicola occupies a greater variety of habitats than currently assumed and that this species could be saprophytic as well as pathogenic. P. acaciicola has been tested as a mycoherbicide and proven successful in the nursery and the field (Wood and Ginns, 2006). Mycoherbicides still form a minor part of weed management, although some investments are being made in this field as agricultural producers are forced by the public, research development and environmental degradation to move away from chemical control. ...
