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Russula is the largest genus in the Russulales and is widespread throughout the world. Almost all Russula species are known to be ectomycorrhizal with high ecological and edible values, and some are lethal poisonous. In this study, four new species belonging to the subgenus Russula crown clade are identified based on morphological and phylogenetic evidence from the Xizang Autonomous Region and other provinces of China. Morphologically, Russula paragraveolens (sect. Polychromae, subsect. Xerampelinae) is mainly characterised by a cherry red to blood red pileus centre, a reddish orange pileus margin; R. pseudograveolens (sect. Polychromae, subsect. Xerampelinae) is characterised by a violet brown to brownish red pileus centre, a pale red to pastel red pileus margin and short basidia; R. shigatseensis (sect. Flavisiccantes, subsect. Lepidinae) is characterised by a brownish orange to madder red pileus centre, pinkish red pileus margin, and having lateral branches or branches of hyphal terminations in pileipellis; R. yadongensis (sect. Tenellae, subsect. Laricinae) is characterised by a dark purplish red pileus centre with brownish purple tints and having isolated to clustered spines of spore ornamentations. Their distinct taxonomic status is confirmed by the positions of the four new species in both the ITS and 4-locus (nucLSU, mtSSU, rpb2, tef1) phylogenetic trees. [ABSTRACT FROM AUTHOR]

By the telescoping method, Sun has recently given some hypergeometric series whose sums are related to π. We investigate these series from the point of view of Gosper's algorithm. Given a hypergeometric term t k , we consider the Gosper summability of r (k) t k for r (k) being a rational function of k. We give an upper bound and a lower bound on the degree of the numerator of r (k) such that r (k) t k is Gosper summable. We also show that the denominator of r (k) can be read off from the Gosper representation of t k + 1 / t k . Based on these results, we give a systematic method to construct series whose sums can be derived from the known ones. We also illustrate the corresponding super-congruences and the q-analogue of the approach. [ABSTRACT FROM AUTHOR]

Russula is a worldwid genus which has a high species diversity. Aiming accurate and rapid species identification, candidate genes nLSU (28S), ITS, tef-1α, mtSSU, rpb1, and rpb2, were analysed as potential DNA barcodes. This analysis included 433 sequences from 38 well-circumscribed Russula species of eight subgenera. Two vital standards were analysed for success species identification using DNA barcodes, specifically inter- and intra-specific variations together with the success rates of PCR amplification and sequencing. Although the gap between inter- and intra-specific variations was narrow, ITS met the qualification standards for a target DNA barcode. Overlapping inter- and intra-specific pairwise distances were observed in nLSU, tef-1α, mtSSU, and rpb2. The success rates of PCR amplification and sequencing in mtSSU and rpb1 were lower than those of others. Gene combinations were also investigated for resolution of species recognition. ITS-rpb2 was suggested as the likely target DNA barcode for Russula, owing to the two viatal standards above. Since nLSU has the lowest minimum of inter-specific variation, and tef-1α has the highest overlap between intra- and inter-species variations among the candidate genes, they are disqualified from the selection for DNA barcode of Russula. [ABSTRACT FROM AUTHOR]

In this paper, a new species,Cystolepiota pseudofumosifolia, is introduced.C.pseudofumosifoliais characterized by granulose or powdery pileus with an anatomic structure that is loosely globose, as well as ellipsoid cells in chains in the pileus covering the cheilocystidia. This new species is compared to the related and similarCystolepiotaspecies in morphology and molecular phylogeny based on Internal transcribed spacer sequences. Both types of data support our specimens as a new species in the genusCystolepiota. [ABSTRACT FROM PUBLISHER]