Jianchu Xu

Find an error

Name: 许建初
Organization: Chinese Academy of Sciences , China
Department: Kunming Institute of Botany
Title: NULL(PhD)

TOPICS

Co-reporter:Kevin D. Hyde;Sajeewa S. N. Maharachchikumbura;Sinang Hongsanan
Fungal Diversity 2017 Volume 84( Issue 1) pp:1-23
Publication Date(Web):15 June 2017
DOI:10.1007/s13225-017-0383-3
The history of assigning ranks to fungi, as well as the relative importance of using divergence time estimates is reviewed. The paper pays tribute to the major mycological players, and especially to David Hawksworth on his 70th birthday and his contribution to fungal ranking in Systema Ascomycetum from 1982 to 1998. Following the conclusion of the latter series, the ranking continued with the Outlines of Ascomycota in 2007 and 2010 and more recently with specific classes in ‘Towards an outline of Sordariomycetes’ and ‘Families of Dothideomycetes’. Earlier classifications based on phenotype were certainly more subjective; however, remarkably many of these old arrangements have stood the test of time. More recently, phylogenetic analyses have provided evidence towards a natural classification, resulting in significant changes in many lineages. The classification arrangements however, are still subjective and dependent on the taxa analysed, resulting in different taxonomic interpretations and schemes, particularly when it comes to ranking. Thus, what have been considered as genera by some, have been introduced as families by others. More recently, estimation of divergence times using molecular clock methods have been used as objective evidence for higher ranking of taxa. A divergence period (i.e. 200–300 MYA) can be used as a criterion to infer when a group of related taxa evolved and what rank they should be given. We compiled data on divergence times for various higher ranking taxa in the Kingdom Fungi. The kingdom evolved 1000–1600 MYA (Stenian–Calymmian), while the presently accepted phyla evolved between 358 and 541 MYA (Devonian–Cambrian). Divergence times for subphyla are generally between 358 and 485 MYA (Devonian–Ordovician), those of classes 145–358 MYA (Jurassic–Carboniferous), subclasses 66–358 MYA (Cretaceous–Carboniferous), orders 23–252 MYA (Paleogene–Triassic), families 2.8–145 MYA (Neogene–Cretaceous), and genera 2.8–66 MYA (Neogene–Paleogene). Thus, there are wide discrepancies in the times different taxa diverged. We provide an overview over Ascomycota, showing how application of temporal banding could affect the recognition of higher taxa at certain rank levels. We then use Sordariomycetes as an example where we use divergence times to provide additional evidence to stabilize ranking of taxa below class level. We propose a series of evolutionary periods that could be used as a guide to determine the various higher ranks of fungi: phyla >550 MYA, subphyla 400–550 MYA; classes 300–400 MYA; subclasses 250–300 MYA, orders 150–250 MYA, and families 50–150 MYA. It is proposed that classification schemes and ranking of taxa should, where possible, incorporate a polyphasic approach including phylogeny, phenotype, and estimate of divergence times.
Co-reporter:Rungtiwa Phookamsak;Dhanushka N. Wanasinghe;Sinang Hongsanan
Fungal Diversity 2017 Volume 87( Issue 1) pp:299-339
Publication Date(Web):02 December 2017
DOI:10.1007/s13225-017-0393-1
Ophiobolus is a large genus of Phaeosphaeriaceae comprising more than 350 possible species, most of which are saprobes on herbaceous plants in Europe and North America. Ophiobolus species are polyphyletic and the type of Ophiobolus is not represented in GenBank. Therefore, an increased taxon sampling of ophiobolus-like taxa and epitypification of the type species, O. disseminans is reported. Multigene phylogenetic analyses of combined LSU, SSU, TEF1-α and ITS sequence data position O. disseminans in a sister clade with O. ponticus and several Entodesmium species in Phaeosphaeriaceae with high support. Therefore, Entodesmium is synonymized under Ophiobolus. Premilcurensis with it type species, P. senecionis also clusters within the Ophiobolus clade and is synonymized under Ophiobolus. Ophiobolus rossicus sp. nov. is introduced and a reference specimen is designated for O. ponticus. Other ophiobolus-like taxa (Ophiobolus sensu lato) can be distinguished as three main groups, which are introduced as new genera. Ophiobolopsis is introduced to accommodate the new species, Ophiobolopsis italica. The new genus Paraophiobolus is introduced to accommodate P. arundinis sp. nov. and P. plantaginis comb. nov. This genus is characterized by hyaline to pale yellowish ascospores, some green-yellowish at maturity, with a swollen cell, terminal appendages and ascospores not separating into part spores. Pseudoophiobolus gen. nov. is introduced to accommodate six new species and two new combinations, viz. Ps. achilleae, Ps. erythrosporus, Ps. galii, Ps. italicus, Ps. mathieui, Ps. rosae, Ps. subhyalinisporus and Ps. urticicola. Pseudoophiobolus is characterized by subhyaline to pale yellowish or yellowish ascospores, with a swollen cell, lack of terminal appendages and ascospores that do not separate into part spores and is related to Nodulosphaeria. An updated tree for Phaeosphaeriaceae based on multigene analysis is also provided.
Co-reporter:Asanka R. Bandara;Samantha C. Karunarathna;Peter E. Mortimer
Mycological Progress 2017 Volume 16( Issue 11-12) pp:1029-1039
Publication Date(Web):02 November 2017
DOI:10.1007/s11557-017-1344-7
In order to fulfill the increasing demand for edible mushrooms and maintain a steady supply throughout the year, it is necessary to domesticate new wild edible mushroom species. In this study, we domesticated Auricularia thailandica, a newly identified edible species that was collected from the wild in Thailand. We compared the growth of A. thailandica in three different growth media: sawdust, wheat husk and sugarcane bagasse. The use of sawdust resulted in the fastest rate of mycelial colonisation at 56.4 ± 1.2 days, pinheads were formed in 14.2 ± 0.4 days and the biological efficiency was 17.1 ± 2.8%. Nutritional analysis showed that A. thailandica contained a higher proportion of protein (12.99 ± 0.05%) and fat (2.93 ± 0.66%) by dry weight than other commercial Auricularia spp. available on the market. The antioxidant potential of A. thailandica varied with the extraction solvent used, and the effective concentration was found to be significantly lower in methanol extract than aqueous extract. Additionally, this species has an attractive reddish orange colour and larger basidiocarps than other commercially available species.
Co-reporter:Stefanie Daniela Goldberg, Yongli Zhao, Rhett D. Harrison, Jutamart Monkai, Yuwu Li, Kating Chau, Jianchu Xu
Agriculture, Ecosystems & Environment 2017 Volume 249(Volume 249) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.agee.2017.08.001
•Annual soil respiration was 15% lower in rubber plantations than in natural forests.•Only dry season soil respiration was lower in rubber plantations compared to forests.•>70% of the soil emitted CO2 originated from respiration above 5 cm soil depth.•Net CO2 production below 5 cm soil depth did not differ between the land-use types.Soil respiration (SR) plays an important role in the global carbon cycle. The widespread and continued conversion of tropical forests to plantations is expected to drastically alter CO2 production in soil, with significant consequences for atmospheric concentrations of this crucial greenhouse gas. In Southeast Asia, rubber plantations are among the most widespread monoculture tree plantations. However, knowledge of how SR differs in rubber plantations compared to natural forests is scarce. In this study, surface CO2 fluxes and soil CO2 concentrations (at 5 cm, 10 cm, 30 cm and 70 cm depths) were measured at regular intervals over a one-year period along slopes at three sites in paired natural tropical forests and mature rubber plantations. Annual surface soil CO2 fluxes were 15% lower in the rubber plantations than in natural forest. This difference was due to substantially lower SR during the dry season in rubber plantations compared to natural forest. During the wet season, SR did not differ significantly between rubber plantations and natural forests. In rubber plantations, soil moisture increased from lower and middle to upper slope positions, but this did not significantly impact SR. Throughout the year, net CO2 production per unit volume in the topsoil (2.5–7.5 cm) exceeded by 2–3 orders of magnitude net CO2 production in the subsoil (7.5–50 cm). However, CO2 originating from 5 cm depth and below in both land cover types could only explain up to 30% of the aboveground measured CO2 flux, indicating that >70% of the total CO2 respired and emitted to the atmosphere originated from the uppermost few cm of the soil. Net CO2 production at different soil depths did not differ significantly between rubber plantations and natural forests. Our results indicate that SR characteristics in mature rubber plantation and natural forest were broadly similar, although dry season soil surface CO2 fluxes were lower in rubber plantations. However, further information on the drivers of CO2 production in the uppermost topsoil layers which are responsible for most CO2 emissions is needed to understand the extent to which these results are generalisable.
Co-reporter:Fredrich Kahrl, Yufang Su, Timm Tennigkeit, Andreas Wilkes, Jianchu Xu, Mei Yan
Biomass and Bioenergy (December 2013) Volume 59() pp:92-99
Publication Date(Web):1 December 2013
DOI:10.1016/j.biombioe.2012.01.043
This paper develops three scenarios for the management of an existing, low productivity, collective forest plot in Southwest China: continuation of the status quo, transition to sustainable forest management (SFM), and conversion to a short rotation species for producing biomass for electricity generation. We examine how economic incentives vary across the three scenarios and how payments for CO2 sequestration and offsets affect incentives. We find that SFM is risky for forest managers and is highly sensitive to revenues from initial thinning; that carbon revenues can lower some of the risks and improve the economics of SFM; but that carbon revenues are effective in incentivizing management changes only if yield response to thinning is moderately high. Energy production from stem wood is too low value to compete with timber, even with revenues from CO2 offsets. However, conversion of existing forests into short rotation species for timber rather than energy is more profitable than any scenario considered here, highlighting the need for regulatory innovations to balance incentives for timber production with conservation goals. The results underscore the importance of improved public sector regulatory, planning, extension, and analysis capacity, as an enabling force for effective climate policies in China’s forestry sector.Highlights► Sustainable forest management (SFM) is risky for forest managers. ► Carbon revenues can lower risks, improve incentives for SFM. ► Energy is too low value to compete with timber as a use of forest biomass. ► Climate policy increases demands on public sector capacity in China’s forest sector.
Co-reporter:Liang Guo, Junhu Dai, Mingcheng Wang, Jianchu Xu, Eike Luedeling
Agricultural and Forest Meteorology (15 February 2015) Volume 201() pp:1-7
Publication Date(Web):15 February 2015
DOI:10.1016/j.agrformet.2014.10.016
5-HYDROXY-7,8-DIMETHOXY-2-PHENYL-4H-CHROMEN-4-ONE
27-Norolean-14-en-28-oicacid, 3-(acetyloxy)-13-methyl-, (3b,13a)-
L-ornithine decarboxylase from E. coli
trypsin
Chitinase
ELEUTHEROSIDE A
L-ORNITHINE