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Ravenelia evansii on Acacia nilotica subsp. indica . a Uredinia on leaflets ex BRIP 53149; b urediniospores and paraphyses ex BRIP 53149; c SEM of urediniospores and paraphyses ex BRIP 53149; d SEM of teliospores ex BRIP 53149; e SEM of hub and spoke ornamentation of teliospore ex BRIP 53149; f uredinia and telia on leaflets ex PREM 2181 (holotype); g teliospore ex PREM 2181 (holotype). Bar: ( a ) = 1 cm. ( b, c, d ) = 10 μm. ( e ) = 1 μm. ( f ) = 1 cm. ( g ) 1 = 10 μm.
Source publication
The two rust fungi, Ravenelia acaciae-arabicae and R. evansii, were both found on Acacia nilotica subsp. indica in southern (Tamil Nadu) and northern (Gujarat) India. R. acaciae-arabicae has been often incorrectly synonymised with R. evansii, although each has distinctive urediniospores, viz. echinulate in R. acaciae-arabicae and verruculose in R....
Context in source publication
Context 1
... & Thirumalachar (1946) gave the diam. of telial heads as 64–92 μm with a mean of 78 μm, we found similar corresponding measurements of 65–105 μm with a mean of 83 – 92 μm (n = 20). Mundkur & Thirumalachar’s (1946) description of R. acaciae- arabicae as having urediniospores minutely echinulate, 20–33 x 17–20 μ in size (mean = 27 x 19 μ), with 8 to 10 scattered germ pores was also similar to those on specimens we collected in India. Fig. 2 Annales Mycologici 10: 440. 1912. Holotype on Acacia robusta , South Africa, Transvaal, near Pretoria, The Willows, 23 Mar. 1912, J.B. Pole Evans 2181 (PREM 2181!), [III]. Uredinia amphigenous, not associated with spots although leaflet tissue on corresponding surface lightly chlorotic, solitary or in groups, ...
Citations
... (= Vachellia nilotica P.J.H. Hurter & Mabb.) by Mundkur and Thirumalachar, and was recently more precisely reported on V. nilotica subsp. indica (Shivas et al. 2013). We report this rust for the first time on V. nilotica subsp. ...
The genus Ravenelia represents the third largest genus of rust fungi and parasitizes a great number of leguminous shrubs and trees, mainly in the subtropics and tropics. Molecular phylogenetic analyses of this genus using nc 28S rDNA and CO3 sequences are presented with a special focus on South African representatives of Ravenelia. Many of the specimens had been collected by us in recent years, mainly from acacia species of the genera Vachellia and Senegalia. Morphological characters were extensively studied using light microscopy and scanning electron microscopy. The analyses resolved several well-supported phylogenetic groups. By linking these groups to their morphology and life cycle characteristics, it was possible to interpret the outcomes in terms of their evolutionary ecology and biogeography. Several characters previously used to define subgeneric groups within Ravenelia were found to be misleading because of assumed convergent evolution. However, host associations, the ability to induce aecial galls as well as the development of two-layered probasidial cells emerged as useful criteria for inferring monophyletic groups. Six novel Ravenelia species were discovered and described. Furthermore, five species represent new reports for South Africa, species descriptions were emended for two taxa, and a new host report emerged for R. inornata.
... These generally matched those of R. evansii Syd. & P. Syd. given in Doidge (1927) and Shivas et al. (2013) and were supported by molecular phylogenetic analyses of nrITS and nrLSU sequence data. These Vachellia species are reported as new hosts for Ravenelia evansii. ...
... These Vachellia species are reported as new hosts for Ravenelia evansii. Despite major congruence of teliospore characters, the range of the teliospore diameter observed by our examinations exceeded the size range of 50-80 μm and 63-90 μm given in Doidge (1927) and Shivas et al. (2013), respectively. Furthermore, the occurrence of two-layered probasidial cells is reported here for the first time Figure 4J). ...
Trees in the genus Vachellia (previously Acacia ) are commonly infected by the gall-inducing rusts Raveneliamacowaniana and R.evansii . Rust galls bearing aecial infections and relating uredinial and telial infections on the leaves of nine Vachellia species not previously recorded to be infected by Ravenelia spp. have recently been collected in South Africa. The rust fungi causing these infections were characterised using molecular phylogenetic analyses of DNA sequence data of the LSU and ITS rDNA regions as well as morphological examinations. The host range of R.macowaniana and R.evansii was thus re-assessed and extended from four to nine species and from one to three species, respectively. Application of Principal Component Analyses (PCA) of telial morphological characters provided evidence of an effect of the host species on the teliospore morphology in R.evansii , but only minor effects in R.macowaniana . A novel gall-inducing Ravenelia sp. closely related to R.macowaniana , was found on Vachelliaxanthophloea and it is described here as R.xanthophloeae .
... These generally matched those of R. evansii Syd. & P. Syd. given in Doidge (1927) and Shivas et al. (2013) and were supported by molecular phylogenetic analyses of nrITS and nrLSU sequence data. These Vachellia species are reported as new hosts for Ravenelia evansii. ...
... These Vachellia species are reported as new hosts for Ravenelia evansii. Despite major congruence of teliospore characters, the range of the teliospore diameter observed by our examinations exceeded the size range of 50-80 μm and 63-90 μm given in Doidge (1927) and Shivas et al. (2013), respectively. Furthermore, the occurrence of two-layered probasidial cells is reported here for the first time Figure 4J). ...
Trees in the genus Vachellia (previously Acacia ) are commonly infected by the gall-inducing rusts Raveneliamacowaniana and R.evansii . Rust galls bearing aecial infections and relating uredinial and telial infections on the leaves of nine Vachellia species not previously recorded to be infected by Ravenelia spp. have recently been collected in South Africa. The rust fungi causing these infections were characterised using molecular phylogenetic analyses of DNA sequence data of the LSU and ITS rDNA regions as well as morphological examinations. The host range of R.macowaniana and R.evansii was thus re-assessed and extended from four to nine species and from one to three species, respectively. Application of Principal Component Analyses (PCA) of telial morphological characters provided evidence of an effect of the host species on the teliospore morphology in R.evansii , but only minor effects in R.macowaniana . A novel gall-inducing Ravenelia sp. closely related to R.macowaniana , was found on Vachelliaxanthophloea and it is described here as R.xanthophloeae .
This study examined the ultrastructure of urediniospores, teliospores, intercellular hyphae and haustoria of the rust fungus: Puccinia pimpinellae on Pimpinella anisum. The morphology and structure of urediniospores and teliospores is similar to those of most other Puccinia species. The ultrastructure of intercellular hyphae and haustoria is mainly similar to those of other rust fungi. The intercellular hyphae are frequently containing two nuclei and an extramural substance is found between their walls and host cell wall. An electron-lucent collar is found around the haustorial neck and the proximal end of the haustorial body. In most cases, two nuclei are detected inside the haustorial body. A fibrillar extrahaustorial matrix is present around the old vacuolated haustoria. Necrotic haustoria are frequently detected inside host cell and encased by a wide sheath containing membranous structures and electron-dense deposits. The association of chloroplasts and nuclei with haustoria is also detected.
Key words: Anise, Puccinia pimpinellae, rust fungi, ultrastructure, dikaryotic haustorium, teliospores, urediniospores.
2013): Survey and prioritisation of potential biological control agents for prickly acacia (Acacia nilotica subsp. indica) in southern India, Biocontrol Science and Technology, 23:6, 646-664 This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings,
