Additions to the rust fungi of South Africa

This paper presents new species, combinations, national reports and host records for the South African rust fungi (Uredinales/Pucciniales). Endophyllum mpenjatiense on cf. Hibiscus sp. (Malvaceae), Phakopsora combretorum (anamorph Uredo combreticola) on the new host Combretum apiculatum (Combretaceae) and Uredo sekhukhunensis on Ziziphus mucronata (Rhamnaceae) are described as new species. Dietelia cardiospermi and E. metalasiae are proposed as new combinations to replace Aecidium cardiospermi on Cardiospermum halicacabum (Sapindaceae) and A. metalasiae on Metalasia spp. (Asteraceae), respectively. Four species are new records for South Africa: Crossopsora antidesmae-dioicae on Antidesma venosum (Euphorbiaceae), Phakopsora ziziphi-vulgaris on Z. mucronata, and Uromyces cypericola and Puccinia subcoronata, both on a new host, Cyperus albostriatus (Cyperaceae). The record of P. subcoronata is the first one from outside the New World. Puccinia scirpi is reported as a possible addition to the South African rust fungi. New host records and observations are presented for Pucciniastrum agrimoniae that is recorded on two new host genera and species, Cliffortia odorata and Leucosidea sericea (Rosaceae), Uromyces cypericola whose urediniospores are described for the first time, Phakopsora stratosa in that spermogonia and Uredo-like aecia were discovered, and for Sphaerophragmium dalbergiae in that characters of the urediniospores are re-evaluated. A lectotype is selected for Aecidium garckeanum and spermogonia are reported for this rust for the first time. The rust fungi of Ehrharta (Poaceae) are discussed and critically evaluated in the light of spore morphology and host species.     

New species, reports, observations and taxonomical changes of southern African rust fungi (Uredinales)

This work presents research on the diversity of the southern African rust mycobiota (Uredinales). It describes new species, lists new reports and adds new information on several rust fungi. Puccinia cornurediata, Puccinia dioscoreae-mundtii, Puccinia horti-kirstenboschi, Puccinia othonnoides, Puccinia rapipes, Puccinia subindumentana, Uredo otholobii and Uromyces lotononidicola are described as new; Puccinia verwoerdiana is assigned to Puccinia lycii as a synonym, and Uredo lotononi to U. lotononidicola. Comprehensive accounts and keys are presented for Puccinia species on Lycium (Solanaceae), Helichrysum and Othonna (Asteraceae). Puccinia butleri and Uromyces bidenticola are new reports for South Africa, and Puccinia spinulosa is new for Namibia. So far, the latter species has only been known from Madagascar, and P. butleri from the Indian subcontinent. Taxonomical novelties are P. cornurediata R. Berndt; P. dioscoreae-mundtii R. Berndt, A.R. Wood & E. Uhlmann; P. horti-kirstenboschi R. Berndt & E. Uhlmann; P. othonnoides R. Berndt, A.R. Wood & E. Uhlmann; P. rapipes R. Berndt & E. Uhlmann; P. subindumentana R. Berndt; U. otholobii R. Berndt, A.R. Wood & E. Uhlmann and U. lotononidicola R. Berndt     

牛紏吴茱萸柄锈菌新种

本文描述了采自海南省琼中县牛紏吴茱萸Evodia trichotoma (Lour.) Pierre(芸香科)上的柄锈菌一新种——Puccinia evodiae-trichotomae J. -y. Zhuang。本种与巴布亚一新几内亚产的吴茱萸Evodia sp.上的另一种柄锈菌Puccinia evodiae Cumm.略近似,但冬孢子堆裸露呈垫状,而后者则深埋于病瘿中。冬孢子形状与大小和后者相仿,然而少数孢子可长达60μm,顶壁有时略增厚,颜色很浅或近几色。镜下可见一些孢子已萌发,推测可能属无眠冬孢型。芸香科植物上的柄锈菌目前仅知10种,本种特征与它们均不相同,故鉴定为新种。本新种模式标本保藏在中国科学院微生物研究所真菌标本室。     

New species of rust fungi from Brazil

New species of rust fungi (Basidiomycota, Uredinales) are described from Brazil: Maravalia allophyli on Allophylus sp., the first Maravalia species on Sapindaceae, Puccinia tianguensis on Hyptis sp. (Lamiaceae), Uredo calatheae on Calathea neoviedii (Marantaceae), and Uredo schizolobii on Schizolobium amazonicum (Caesalpiniaceae). Puccinia fuireniphila is proposed as a new name for Puccinia fuirenicola.     

On some rust fungi (Uredinales) collected in an Acacia koa–Metrosideros polymorpha woodland, Mauna Loa Road, Big Island, Hawaii

Nine species of rust fungi (Uredinales) were found during a 1-day field study in an Acacia koa–Metrosideros polymorpha woodland in Volcanoes National Park on Big Island, Hawaii. Two species, both found on Acacia koa, are native (endemic) rusts whereas 7 species are nonnative on nonnative hosts, highlighting the high proportion of introduced species in the Hawaiian flora even in more or less natural habitats. One species, Uromyces linearis on Panicum repens, constitutes the first record of this rust for the Hawaiian archipelago, bringing the total to 93 species on the islands, 70 (75.3%) of which are introduced. The species records are annotated with emphasis on the geographic origin of each taxon. In addition, the study has led to the molecular reevaluation of the genus Racospermyces, indicating that it is synonymous with Endoraecium, and six new combinations are proposed for the species previously placed in Racospermyces. The high number of introduced species in Hawaii coupled with the paucity of native species when compared to other global regions is discussed.     

<Emphasis Type="Italic">Puccinia calystegiae-soldanellae</Emphasis>, a new rust species on <Emphasis Type="Italic">Calystegia soldanella</Emphasis> from Japan

A rust species on Calystegia soldanella in Japan has been treated as Puccinia convolvuli to date. However, morphological characteristics of specimens on C. soldanella collected from Japan are significantly different from those of specimens on other Calystegia and Convolvulus species from different areas of the world. It is proved by inoculation experiment that the rust on C. soldanella is specific to C. soldanella. Based on these results, Puccinia rust on C. soldanella from Japan is described as a new species, Puccinia calystegiae-soldanellae.     

The rust fungi of <Emphasis Type="Italic">Luzuriaga</Emphasis> (Luzuriagaceae) with description of a new species, <Emphasis Type="Italic">Puccinia luzuriagae-polyphyllae</Emphasis>

Three species of rust fungi (Uredinales), Puccinia perforans, P. fuegiana (= Uromyces skottsbergii), and Aecidium callixenis have been described on members of Luzuriaga (Luzuriagaceae). Puccinia luzuriagae-polyphyllae is added as a new species on Luzuriaga polyphylla from Chile. The rust had been confused hitherto with P. perforans occurring on L. radicans. Both species differ from P. fuegiana on L. marginata by the absence of a uredinial state and several telial characters. The investigated collections of Puccinia species on Luzuriaga indicate that each is restricted to a single host species. A determination key is presented.     

Taxonomy and phylogeny of Puccinia lagenophorae: a study using rDNA sequence data, morphological and host range features

Puccinia lagenophorae is a rust fungus originating from Australasia which has spread throughout the world. A phylogenetic analysis of taxa related to this species was performed using rDNA (LSU, ITS) sequence data. The analyses revealed a well-supported cluster including all specimens of P. lagenophorae. By evaluating morphological and sequence data, the species is taxonomically re-defined and a list of synonyms is provided. Puccinia distincta on Bellis perennis, a species recently separated from P. lagenophorae, P. saccardoi, a species on the Goodeniaceae, and P. byliana, a species so far only known from South Africa, are reduced to synonymy in P. lagenophorae, as are several other species. Our analysis indicates that P. lagenophorae is likely not derived from the northern hemisphere species P. obscura, but from a species from Australia host-alternating between Asteraceae (aecial host) and Cyperaceae/Juncaceae (telial host). Another related species, P. stylidii (on Stylidium sp., Stylidiaceae) may have been derived from the same parental species as P. lagenophorae. From ontogenetical and morphological studies, the presence of pycnia could not be confirmed in the life cycle of this species, and the width of the pedicel of teliospores at the point of attachment was found to be highly variable and not a taxonomic character. The number of known host species is approximately 150, including 41 new host plants recorded herein.     

Molecular mapping of stem and leaf rust resistance in wheat

Stem rust caused by Puccinia graminis f. sp. tritici Eriks and Henn and leaf rust caused by Puccinia triticina Rob. ex Desm. are major constraints to wheat production worldwide. In the present study, F₄-derived SSD population, developed from a cross between Australian cultivars ‘Schomburgk’ and ‘Yarralinka’, was used to identify molecular markers linked to rust resistance genes Lr3a and Sr22. A total of 1,330 RAPD and 100 ISSR primers and 33 SSR primer pairs selected ob the basis of chromosomal locations of these genes were used. The ISSR marker UBC 840₅₄₀ was found to be linked with Lr3a in repulsion at a distance of 6.0 cM. Markers cfa2019 and cfa2123 flanked Sr22 at a distance of 5.9 cM (distal) and 6.0 cM (proximal), respectively. The use of these markers in combination would predict the presence or absence of Sr22 in breeding populations. A previously identified PCR-based diagnostic marker STS638 linked to Lr20 was validated in this population. This marker showed a recombination value of 7.1 cM with Lr20.     

Mapping genes Lr53 and Yr35 on the short arm of chromosome 6B of common wheat with microsatellite markers and studies of their association with Lr36

The rust resistance genes Lr53 and Yr35, transferred to common wheat from Triticum dicoccoides, were reported previously to be completely linked on chromosome 6B. Four F ₃ families were produced from a cross between a line carrying Lr53 and Yr35 (98M71) and the leaf rust and stripe rust susceptible genotype Avocet “S” and were rust tested using Puccinina triticina pathotype 53-1,(6),(7),10,11 and Puccinia striiformis f. sp. tritici pathotype 110 E143 A+. The homozygous resistant lines produced infection types of “;1−” and “;N” to these pathotypes, respectively. The Chi-squared tests indicated goodness-of-fit of the data for one leaf rust gene and one stripe rust gene segregation. Linkage analysis using this population demonstrated recombination of 3% between the genes. Microsatellite markers located on the short arm of chromosome 6B were used to map the genes, with the markers cfd1 and gwm508 being mapped approximately 1.1 and 4.5 cM, respectively, proximal to Lr53. Additional studies of the relationship between Lr36, also located on the short arm of chromosome 6B, and Lr53 indicated that the two genes were independent.     

Effect of Water Potential and Temperature on the Germination of Four Species of African Savanna Trees

The germination responses of seeds from the African tree speciesColophospermum mopane, Combretum apiculatum, Acacia tortilisand Acacia karroo under varying regimes of temperature and waterstress (induced by incubation in PEG 8000) are reported Withthe exception of Combretum (at –0.14 and –0.29 MPa)and Colophospermum (at –0.29 MPa), incubation in PEG decreasedthe maximum achieved germination percentage (90–100% forall species), but did not extend the germination lag (exceptin Combretum) or affect the time required to reach maximum germinationCombretum and Colophospermum were found to germinate under thewidest range of temperatures and water potentials, for example,as strongly negative as –1.0 MPa at 20 and 30 °C,respectively These seeds also showed greater or equivalent hypocotylelongation in PEG solutions creating potentials of –0.14,–0.29 or –0.51 MPa when compared with seeds germinatedin water, indicating an additional stress adaptation Acaciaspecies showed progressive reduction in germination rates andradicle elongation in response to decreasing water potentialExperiments giving pre-imbibition treatments in water priorto transfer to PEG solutions showed that both Acacia speciesgerminated at approximately 90% if given such pre-treatmentand less than 10% if transferred directly to PEG It is concludedthat the most stress-adapted species studied are Colophospermummopane and Combretum apiculatum, a finding generally correlatedwith the growth habit of these trees Colophospermum mopane, Combretum apiculatum, Acacia tortilis, Acacia karroo, germination, water stress, Zimbabwe     

Notes on some rust fungi in Vietnam

Sixteen rust species and two unconnected Peridermium collected in Vietnam are enumerated. For all the rust species except Hemileia vastarix, Olivea tectonae, and Puccinia thwaitesii, these are the first records of their occurrence in Vietnam. Some taxonomic and pathological considerations are noted for two economically important pine stem rusts.     

Materials for the rust flora of Japan VI

Ten rust species are reported with new information on range of distribution and host relations. Among these,Puccinia fagopyricola andUromyces junci were new to Japan, andAecidium araliae was newly found in northern Honshu. Additional collections were made ofBlastospora smilacis, Puccinia malvacearum andP. orbicula in northern Honshu. New hosts were added toColeosporium solidaginis, C. tussilaginis, Phragmidium miyakeanum andPuccinia caricis, and a new Japanese host toPuccinia malvacearum.V: Trans. Mycol. Soc. Japan29: 471–478, 1988.     

Powdery mildew resistance and Lr34/Yr18 genes for durable resistance to leaf and stripe rust cosegregate at a locus on the short arm of chromosome 7D of wheat

The incorporation of effective and durable disease resistance is an important breeding objective for wheat improvement. The leaf rust resistance gene Lr34 and stripe rust resistance gene Yr18 are effective at the adult plant stage and have provided moderate levels of durable resistance to leaf rust caused by Puccinia triticina Eriks. and to stripe rust caused by Puccinia striiformis Westend. f. sp. tritici. These genes have not been separated by recombination and map to chromosome 7DS in wheat. In a population of 110 F₇ lines derived from a Thatcher × Thatcher isogenic line with Lr34/Yr18, field resistance to leaf rust conferred by Lr34 and to stripe rust resistance conferred by Yr18 cosegregated with adult plant resistance to powdery mildew caused by Blumeria graminis (DC) EO Speer f. sp. tritici. Lr34 and Yr18 were previously shown to be associated with enhanced stem rust resistance and tolerance to barley yellow dwarf virus infection. This chromosomal region in wheat has now been linked with resistance to five different pathogens. The Lr34/Yr18 phenotypes and associated powdery mildew resistance were mapped to a single locus flanked by microsatellite loci Xgwm1220 and Xgwm295 on chromosome 7DS.     

Teliospore-inducing activity for wheat leaf rust in the extracts of various host plant leaves infected with telia of rust fungi

MeOH and water extracts were obtained from 16 species of infected leaves with rust fungi belonging to 18 species in 6 families: Pucciniaceae, Melampsoraceae, Coleosporiaceae, Pileolariaceae, Phragmidiaceae, and Phakopsoraceae. All the extracts of rust-infected plants with telia showed the teliospore-inducing activity for wheat leaf rust (Puccinia recondita f. sp. tritici).     

<Emphasis Type="Italic">Enigmagraptus</Emphasis> n. gen., a new graptoloid (Přídolí, Silurian,New South Wales,Australia)

Enigmagraptus n. gen. comprises a group of the smallest known graptolites, with problematical evolutionary ancestors. The species described, all of Přídolí age are:E. yassensis (Rickards &Wright, 1999),E. cf.yassensis, E. mitchelli (Rickards &Wright, 1999) andE. pennyae n. sp.      

Composition and distribution of indigenous trees and shrubs as possible criteria for indicating adapted species in semi‐arid rangelands

This study assessed the composition and natural distribution of indigenous trees and shrubs as possible criteria for selecting suitable species for rehabilitation of degraded sites in semi‐arid rangelands. Study sites were identified at Nthangu, Kathonzweni and Kibwezi forests of Makueni County, Kenya using existing vegetation, agro‐climatic maps and Landsat imageries. The sites had mean annual rainfalls of 974 mm, 700 mm and 616 mm, respectively, and moisture indices of 49%, 35% and 32%. Data were collected by establishing sample plots and assessing species counts and diameters at breast height (DBH). Basal area, relative dominance, relative abundance, relative frequency and important value indices (IVIs) were computed for individual families and species at each site. The number of families, genera and species declined from Nthangu (33, 60, 77) through Kibwezi (30, 48, 70) to Kathonzweni (28, 42, 69). Corresponding mean basal areas were 16.7 m² ha^?1, 76.8 m² ha^?1 and 19.3 m² ha^?1. The families Combretaceae, Burseraceae and Mimosaceae were the most important and widely distributed. Based on ecological importance values, candidate species for rehabilitation of degraded sites at Nthangu, Kathonzweni and Kibwezi were Combretum molle and Acacia hockii; Combretum collinum, Commiphora campestris and Acacia tortilis; and Commiphora africana and A. tortilis, respectively.     

Morphological and molecular characterisation of Puccinia lagenophorae, now present in central North America

In June 2004, a rust fungus not previously reported for Oklahoma was found occurring naturally on the weed, common groundsel, Senecio vulgaris, in pots in a commercial container nursery in northeastern Oklahoma. Host symptoms and morphology of teliospores and aeciospores of the fungus were consistent with those of Puccinia lagenophorae, a recent introduction into North America that has, as yet, been reported only on the East and West Coasts of the USA. This is the first report of the rust in central regions of North America. The rust is believed to be native to Australia and New Zealand and subsequently reported in most continents on numerous species and genera of the Asteraceae. Some authors in Europe consider the rust on Bellis as different from the one on Senecio, naming it Puccinia distincta. Our ITS1‐5.8S‐ITS2 ribosomal DNA sequence data, however, show homology with P. distincta sequences from Europe, indicating there is only one morphologically‐variable polyphagous species. Presumably, the rust was introduced into Oklahoma on infected plants from the West Coast of the USA, the source of most plant material in the commercial nursery where it was found. The rust is potentially important on several ornamental Asteraceae in North America as it has become in Europe, where it spreads rapidly throughout that continent following its introduction there in the early 1960s.