Showing papers by "Hiran A. Ariyawansa published in 2019"
TL;DR: This study summarizes a historical fossil outline with a reliable minimum age for 16 calibrating points viz. crown of Aigialus, Anzia, Aspergillus, Asterina, Calicium chlorosporum–C.
Abstract: Inaccurate taxonomic placement of fossils can lead to the accumulation of errors in molecular clock studies and their generated evolutionary lineages. There are limited fossil data that can be used in divergence time estimations. Therefore, reliable morphological characterization and taxonomical identification of fossil fungi are extremely important. Most fossils of Dothideomycetes and Sordariomycetes are from the early Cenozoic (66–23 Mya), with fewer from the late Mesozoic (174–145 Mya). However, it is hard to distinguish some fossil descriptions as photographs and illustrations are unclear; thus, the validity of using these fossils in calibrations of molecular clocks is problematic. This study brings scattered paleobiological data on selected fossil Ascomycota, using descriptions, fossil images and illustrations, coupled with recent age estimations, and taxonomic and phylogenetic affinity of extant species. As an integrated approach, this study summarizes a historical fossil outline with a reliable minimum age for 16 calibrating points viz. crown of Aigialus, Anzia, Aspergillus, Asterina, Calicium chlorosporum–C. nobile, Capnodiales, Chaenotheca, Colletotrichum, Diaporthales, Meliola, Ophiocordyceps, Microthyriales, Microthyrium, Muyocopron, Pezizomycotina and Stigmatomyces. A scheme of Ascomycota ancient lineages is also provided in order to improve divergence time estimations.
44 citations
TL;DR: In Taiwan, strawberry (Fragaria × ananassa Duch.) is a high-value crop with an average annual cultivated area of ∼500 ha in the last 5 years, with ‘Taoyuan No. 1’ as the predominant cultivar for more than 30 years and anthracnose has become more destructive over the past decade.
Abstract: In Taiwan, strawberry (Fragaria × ananassa Duch.) is a high-value crop with an average annual cultivated area of ∼500 ha in the last 5 years. Over 90% of strawberry cultivation is in Miaoli County, with ‘Taoyuan No. 1’ as the predominant cultivar for more than 30 years. Anthracnose has become more destructive over the past decade. Although Colletotrichum gloeosporioides, C. dematium, C. fragariae, and C. acutatum were mentioned as the causal agents of strawberry anthracnose in Taiwan (Plant Protection Information System; https://otserv2.tactri.gov.tw/ppm/), we lack information on the isolation, pathogenicity, and morphological or molecular identification of the pathogen. From 2010 to 2016, we surveyed anthracnose in strawberries in Miaoli County; more than 50% of diseased plants showed typical anthracnose crown rot (ACR) symptoms (McInnes et al. 1992). ACR caused up to 30 to 40% plant loss during the seedling stage and ∼20% after transplanting. Infected crown tissue initially showed red and white marbling and then gradually brown rot, followed by rapid wilting of the entire plant. Anthracnose symptoms were observed in other parts of the plant, including leaves, petioles, runners, fruits, and roots. Symptoms appeared as circular black spots on the leaves and withering and girdling on runners. To isolate the causal agent, approximately 0.2 × 0.2-cm fragments of diseased crowns were surface disinfested with 1% sodium hypochlorite, triple rinsed with sterile water, and then placed onto 1.5% water agar. After 2 to 3 days, extended single hyphal tips from tissues were transferred to potato dextrose agar and incubated for 7 days at 25°C under a 12-h/12-h photoperiod. Colonies were initially white, later became somewhat zonate, velvety, light gray on the upper side and gray on the reverse side of plates, with concentric rings of salmon sporodochia. Conidia were 9.68 to 17.95 × 3.88 to 5.84 µm (14.53 ± 0.31 × 4.99 ± 0.08 µm, n = 90), hyaline, oblong to cylindrical, with round obtuse ends. Morphological characteristics of the causal agent resembled species belonging to the C. gloeosporioides species complex (Weir et al. 2012). To confirm the species identification, we extracted genomic DNA from 10 isolates by using the Plant Genomic DNA Extraction Miniprep System (Viogene, Taipei) and polymerase chain reaction–amplified the internal transcribed spacer (ITS) region, chitin synthase (CHS-1), actin (ACT), β-tubulin 2 (TUB2), calmodulin (CAL), and intergenic region of Apn2 and MAT1-2-1 (ApMAT) with published primers (Carbone and Kohn 1999; O’Donnell and Cigelnik 1997; Silva et al. 2012; Weir et al. 2012; White et al. 1990). Sequences were submitted to GenBank (accession nos. MK174223 [ITS], MK174224 [CHS-1], MK174225 [ACT], MK174226 [TUB2], MK174227 [CAL], and MK174228 [ApMAT]). The ITS, CHS-1, ACT, TUB2, CAL, and ApMAT sequences were compared with the GenBank nr database, restricted to type material. Results showed 98 to 99% identity to C. siamense (syn. C. dianesei and C. melanocaulon) (Liu et al. 2016; Prihastuti et al. 2009), which belongs to the C. gloeosporioides species complex, with the corresponding sequences (ITS: NR_144800; CHS-1: KX094094; ApMAT: KX094304 [Lima et al. 2013]; ACT: KX093987; TUB2: KX094290; and CAL: KX094036 [Doyle et al. 2013]). Koch’s postulates were fulfilled for two isolates (ML133 and ML612) by spraying 1 × 10⁶ conidia/ml suspension on seedlings until run-off at the four- to five-leaf stage (two trials per isolate, n = 5 seedlings per trial). Inoculated plants were covered with plastic bags (>90% relative humidity) for 24 h at 30°C and then maintained in a growth chamber at 30°C, 70% relative humidity, under a 12-h/12-h photoperiod. After 7 days, all inoculated plants showed typical necrotic leaf spots and wilt symptoms similar to those in the field. Control plants sprayed with sterile water had no symptoms (n = 5 per trial). Longitudinal sections of the inoculated crown showed reddish-brown and white-marbled necrosis. The fungi were reisolated from lesions of diseased leaves or crowns with 100% frequency (n ≥ 3 isolates per trial), and morphological characteristics and gene sequences were identical to the original isolates. To our knowledge, this is the first report of C. siamense causing ACR of strawberry in Taiwan. The disease has the potential for causing serious losses to the strawberry industry in Taiwan, and research is needed on management strategies to minimize losses.
12 citations
TL;DR: The data concluded that the taxon represents a novel genus of the family Phaeosphaeriaceae and the generic name Hydeomyces and the species name H. desertipleosporoides are introduced for the new taxon.
Abstract: Specimens of a new pleosporalean taxon were obtained on the bark of Juniperus excels from the northern mountains of Oman; from the Jebel Akhdar (‘Green Hills’). Sequence analyses based on the regions of large subunit rRNA (LSU), small subunit rRNA (SSU), translation elongation factor 1-α (TEF) and internal transcribed spacers (ITS) were performed to resolve the phylogenetic relationships of the new taxon in Phaeosphaeriaceae. The data concluded that the taxon represents a novel genus of the family Phaeosphaeriaceae and the generic name Hydeomyces and the species name H. desertipleosporoides are introduced for the new taxon. An outline of the characters which differentiate the new genus from phylogenetically closely related genera Dematiopleospora and Dlhawksworthia is given and its morphology of asexual and sexual morphs is described.
11 citations
TL;DR: A new endophyte species within the genus Deniquelata was isolated from the branches of Persian oak trees in Zagros forests, Iran and it was demonstrated to be a new species, D. quercina.
Abstract: In this study, a new endophyte species within the genus Deniquelata (Didymosphaeriaceae) was isolated from the branches of Persian oak trees (Quercus brantii) in Zagros forests, Iran. The maximum parsimony and Bayesian analyses of 18S, 28S and ITS, rDNA sequence data revealed that the isolates were distinct from other species of the Deniquelata. Based on molecular phylogenetic and morphological characteristics, this fungus was demonstrated to be a new species, Deniquelata quercina. Detailed descriptions and illustrations were provided for D. quercina and it was compared with other known species in the genus.
5 citations
TL;DR: An Ophiosphaerella taxon that is new to science isolated from Yushania niitakayamensis in Cilai Mountain, Taiwan is described and shown to be different from closely related species O. aquaticus and O. agrostidis based on distinct size differences of the ascomata, asci, ascospores, host and DNA sequences data.
Abstract: The genus Ophiosphaerella contains 14 formerly illustrated species and is characterized by papillated ascomata bearing fissitunicate cylindrical asci frequently narrower near the base, with a short furcate pedicel and filamentous, pale brown, multi-septate ascospores without swollen cells or separating into part spores. We describe an Ophiosphaerella taxon that is new to science isolated from Yushania niitakayamensis in Cilai Mountain, Taiwan. We conducted polyphasic methods using single and multi-locus (ITS, LSU, SSU, and tef1-α) phylogenetic reconstruction united with morphology to evaluate the natural classification of the novel taxon. The results show that our Ophiosphaerella isolates are different from closely related species O. aquaticus and O. agrostidis based on distinct size differences of the ascomata, asci, ascospores, host and DNA sequences data, thus should be recognised here as a new taxon Ophiosphaerella taiwanica sp. nov.
4 citations