Jianchu Xu

Fungal diversity notes 709???839: taxonomic and phylogenetic contributions to fungal taxa with an emphasis on fungi on Rosaceae

AbstractThis paper is the seventh in the Fungal Diversity Notes series, where 131 taxa accommodated in 28 families are mainly described from Rosa (Rosaceae) and a few other hosts. Novel fungal taxa are described in the present study, including 17 new genera, 93 new species, four combinations, a sexual record for a species and new host records for 16 species. Bhatiellae, Cycasicola, Dactylidina, Embarria, Hawksworthiana, Italica, Melanocucurbitaria, Melanodiplodia, Monoseptella, Uzbekistanica, Neoconiothyrium, Neopaucispora, Pararoussoella, Paraxylaria, Marjia, Sporormurispora and Xenomassariosphaeria are introduced as new ascomycete genera. We also introduce the new species Absidia jindoensis, Alternaria doliconidium, A. hampshirensis, Angustimassarina rosarum, Astragalicola vasilyevae, Backusella locustae, Bartalinia rosicola, Bhatiellae rosae, Broomella rosae, Castanediella camelliae, Coelodictyosporium rosarum, Comoclathris rosae, C. rosarum, Comoclathris rosigena, Coniochaeta baysunika, C. rosae, Cycasicola goaensis, Dactylidina shoemakeri, Dematiopleospora donetzica, D. rosicola, D. salsolae, Diaporthe rosae, D. rosicola, Endoconidioma rosae-hissaricae, Epicoccum rosae, Hawksworthiana clematidicola, H. lonicerae, Italica achilleae, Keissleriella phragmiticola, K. rosacearum, K. rosae, K. rosarum, Lophiostoma rosae, Marjia tianschanica, M. uzbekistanica, Melanocucurbitaria uzbekistanica, Melanodiplodia tianschanica, Monoseptella rosae, Mucor fluvius, Muriformistrickeria rosae, Murilentithecium rosae, Neoascochyta rosicola, Neoconiothyrium rosae, Neopaucispora rosaecae, Neosetophoma rosarum, N. rosae, N. rosigena, Neostagonospora artemisiae, Ophiobolus artemisiicola, Paraconiothyrium rosae, Paraphaeosphaeria rosae, P. rosicola, Pararoussoella rosarum, Parathyridaria rosae, Paraxylaria rosacearum, Penicillium acidum, P. aquaticum, Phragmocamarosporium rosae, Pleospora rosae, P. rosae-caninae, Poaceicola agrostina, P. arundinicola, P. rosae, Populocrescentia ammophilae, P. rosae, Pseudocamarosporium pteleae, P. ulmi-minoris, Pseudocercospora rosae, Pseudopithomyces rosae, Pseudostrickeria rosae, Sclerostagonospora lathyri, S. rosae, S. rosicola, Seimatosporium rosigenum, S. rosicola, Seiridium rosarum, Setoseptoria arundelensis, S. englandensis, S. lulworthcovensis, Sigarispora agrostidis, S. caryophyllacearum, S. junci, S. medicaginicola, S. rosicola, S. scrophulariae, S. thymi, Sporormurispora atraphaxidis, S. pruni, Suttonomyces rosae, Umbelopsis sinsidoensis, Uzbekistanica rosae-hissaricae, U. yakutkhanika, Wojnowicia rosicola, Xenomassariosphaeria rosae. New host records are provided for Amandinea punctata, Angustimassarina quercicola, Diaporthe rhusicola, D. eres, D. foeniculina, D. rudis, Diplodia seriata, Dothiorella iberica, Lasiodiplodia theobromae, Lecidella elaeochroma, Muriformistrickeria rubi, Neofusicoccum australe, Paraphaeosphaeria michotii, Pleurophoma pleurospora, Sigarispora caulium and Teichospora rubriostiolata. The new combinations are Dactylidina dactylidis (=Allophaeosphaeria dactylidis), Embarria clematidis (=Allophaeosphaeria clematidis), Hawksworthiana alliariae (=Dematiopleospora alliariae) and Italica luzulae (=Dematiopleospora luzulae). This study also provides some insights into the diversity of fungi on Rosa species and especially those on Rosa spines that resulted in the characterisation of eight new genera, 45 new species, and nine new host records. We also collected taxa from Rosa stems and there was 31% (20/65) overlap with taxa found on stems with that on spines. Because of the limited and non-targeted sampling for comparison with collections from spines and stems of the same host and location, it is not possible to say that the fungi on spines of Rosa differ from those on stems. The study however, does illustrate how spines are interesting substrates with high fungal biodiversity. This may be because of their hard structure resulting in slow decay and hence are suitable substrates leading to fungal colonisation. All data npresented herein are based on morphological examination of specimens, coupled with phylogenetic sequence data to better integrate taxa into appropriate taxonomic ranks and infer their evolutionary relationships.

A phylogenetic census of global diversity of gut anaerobic fungi and a new taxonomic framework

Obligate anaerobic fungi of the phylum Neocallimastigomycota play a key role in digesting fibrous feeds in the gut of herbivores, but little is known about their global diversity. In this study, the collective diversity of gut anaerobic fungi was examined using all curated internal transcribed spacer 1 (ITS1) sequences of anaerobic gut fungi available in GenBank. The 262,770 quality-checked fungal ITS1 sequences downloaded from GenBank were assigned to 274 operational taxonomic units (OTUs) at the approximate species level. Of these approximate species-equivalent (Sp-eq) OTUs, 119 were represented by at least five ITS1 sequences, with 38 containing known species and 81 containing no known species. Based on a rarefaction analysis, the currently available ITS1 sequences represent nearly all the major species of gut anaerobic fungi, but much more sequencing effort is needed to assess the actual richness of minor OTUs. One dataset of ITS1 reference sequences (referred to as AF-RefSeq) and one comprehensive taxonomic framework are also presented, and they are shown to be suitable for taxonomic classification of most of the ITS1 sequences in GenBank. The results of the present study may help guide future studies involving taxonomic and phylogenetic analysis of ITS1 sequences of anaerobic fungi and targeted isolation and characterization of new anaerobic fungi.

Determinants of livelihood vulnerability in farming communities in two sites in the Asian Highlands

ABSTRACT To identify the indicators of adaptive capacity that determine vulnerability of households, an intensive investigation was conducted in farming communities at two locations in the Asian highlands. Livelihood vulnerability was assessed, classified to four categories and regressed against current adaptive capacity using logistic regression. Household head’s education, irrigated land, non-agricultural income, and technologies used were associated with adaptive capacity. The strengthening of human, natural and financial capital is identified as the best means of managing risk in farming communities in this mountainous region.

Identification of endophytic fungi from leaves of Pandanaceae based on their morphotypes and DNA sequence data from southern Thailand

Abstract The authors established the taxonomic status of endophytic fungi associated with leaves of Pandanaceae collected from southern Thailand. Morphotypes were initially identified based on their characteristics in culture and species level identification was done based on both morphological characteristics and phylogenetic analyses of DNA sequence data. Twenty-two isolates from healthy leaves were categorised into eight morphotypes. Appropriate universal primers were used to amplify specific gene regions and phylogenetic analyses were performed to identify these endophytes and established relationships with extant fungi. The authors identified both ascomycete and basidiomycete species, including one new genus, seven new species and nine known species. Morphological descriptions, colour plates and phylogenies are given for each taxon.

Comparison of Pixel- and Object-Based Approaches in Phenology-Based Rubber Plantation Mapping in Fragmented Landscapes

The increasing expansion of rubber plantations throughout East and Southeast Asia urgently requires improved methods for effective mapping and monitoring. The phenological information from rubber plantations was found effective in rubber mapping. Previous studies have mostly applied rule-pixel-based phenology approaches for rubber plantations mapping, which might result in broken patches in fragmented landscapes. This study introduces a new paradigm by combining phenology information with object-based classification to map fragmented patches of rubber plantations in Xishuangbanna. This research first delineated the time windows of the defoliation and foliation phases of rubber plantations by acquiring the temporal profile and phenological features of rubber plantations and natural forests through the Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data. To investigate the ability of finer resolution images at capturing the temporal profile or phenological information, 30 m resolution Landsat image data were used to capture the temporal profile, and a phenology algorithm to separate rubber plantations and natural forests was then defined. The derived phenology algorithm was used by both the object-based and pixel-based classification to investigate whether the object-based approach could improve the mapping accuracy. Whether adding the phenology information to the object-based classification could improve rubber plantation mapping accuracy in mountainous Xishuangbanna was also investigated. This resulted in three approaches: rule-pixel-based phenology, rule-object-based phenology, and nearest-neighbor-object-based phenology. The results showed that the rule-object-based phenology approaches (with overall accuracy 77.5% and Kappa Coefficients of 0.66) and nearest-neighbor-object-based phenology approach (91.0% and 0.86) achieved a higher accuracy than that of the rule-pixel-based phenology approach (72.7% and 0.59). The results proved that (1) object-based approaches could improve the accuracy of rubber plantation mapping compared to the pixel-based approach and (2) incorporating the phenological information from vegetation improved the overall accuracy of the thematic map.

Genetic Diversity Analysis Reveals Genetic Differentiation and Strong Population Structure in Calotropis Plants

The genus Calotropis (Asclepiadaceae) is comprised of two species, C. gigantea and C. procera, which both show significant economic potential for use of their seed fibers in the textile industry, and of their bioactive compounds as new medicinal resources. The available wild-sourced germplasm contains limited genetic information that restricts further germplasm exploration for the purposes of domestication. We here developed twenty novel EST-SSR markers and applied them to assess genetic diversity, population structure and differentiation within Calotropis. The polymorphic information index of these markers ranged from 0.102 to 0.800; indicating that they are highly informative. Moderate genetic diversity was revealed in both species, with no difference between species in the amount of genetic diversity. Population structure analysis suggested five main genetic groups (Ku2009=u20095) and relatively high genetic differentiation (FSTu2009=u20090.528) between the two species. Mantel test analysis showed strong correlation between geographical and genetic distance in C. procera (ru2009=u20090.875, pu2009=u20090.020) while C. gigantea showed no such correlation (ru2009=u20090.390, pu2009=u20090.210). This study provides novel insights into the genetic diversity and population structure of Calotropis, which will promote further resource utilization and the development of genetic improvement strategies for Calotropis.

Response to climate change of montane herbaceous plants in the genus Rhodiola predicted by ecological niche modelling

Climate change profoundly influences species distributions. These effects are evident in poleward latitudinal range shifts for many taxa, and upward altitudinal range shifts for alpine species, that resulted from increased annual global temperatures since the Last Glacial Maximum (LGM, ca. 22,000 BP). For the latter, the ultimate consequence of upward shifts may be extinction as species in the highest alpine ecosystems can migrate no further, a phenomenon often characterized as “nowhere to go”. To predict responses to climate change of the alpine plants on the Qinghai-Tibetan Plateau (QTP), we used ecological niche modelling (ENM) to estimate the range shifts of 14 Rhodiola species, beginning with the Last Interglacial (ca. 120,000–140,000 BP) through to 2050. Distributions of Rhodiola species appear to be shaped by temperature-related variables. The southeastern QTP, and especially the Hengduan Mountains, were the origin and center of distribution for Rhodiola, and also served as refugia during the LGM. Under future climate scenario in 2050, Rhodiola species might have to migrate upward and northward, but many species would expand their ranges contra the prediction of the “nowhere to go” hypothesis, caused by the appearance of additional potential habitat concomitant with the reduction of permafrost with climate warming.

Morpho-Molecular Characterization of Two Ampelomyces spp. (Pleosporales) Strains Mycoparasites of Powdery Mildew of Hevea brasiliensis

Powdery mildew disease of rubber affects immature green leaves, buds, inflorescences, and other immature tissues of rubber trees, resulting in up to 45% losses in rubber latex yield worldwide. The disease is often controlled by dusting the diseased plants with powdered sulfur, which can have long-term negative effects on the environment. Therefore, it is necessary to search for alternative and environmentally friendly control methods for this disease. This study aimed to identify mycoparasites associated with rubber powdery mildew species, and characterize them on the basis of morpho-molecular characteristics and phylogenetic analyses of ITS rDNA regions. We observed that the Ampelomyces fungus parasitizes rubber powdery mildew, and eventually destroys it. Furthermore, on the basis of phylogenetic analyses and morphological characteristics we confirmed that the Ampelomyces mycoparasite isolated from rubber powdery mildew is closely related to other mycohost taxa in the Erysiphe genus. A total of 73 (71 retrieved from GenBank and two obtained from fresh collections of rubber powdery mildew fungi) Ampelomyces spp. were analyzed using ITS rDNA sequences and 153 polymorphic sites were identified through haplotypic analyses. A total of 28 haplotypes (H1–H28) were identified to have a complex network of mutation events. The results from phylogenetic tree constructed on the basis of maximum likelihood analyses, and the haplotype network tree revealed similar relationships of clustering pattern. This work presents the first report on morpho-molecular characterization of Ampelomyces species that are mycoparasites of powdery mildew of Hevea brasiliensis.