Botrytis polyphyllae: A New Botrytis Species Causing Gray Mold on Paris polyphylla.

Paris polyphylla is an important perennial medicinal plant in China. A disease similar to gray mold on P. polyphylla occurred at the seedling stage in March 2016 and 2017 in Tengchong city, Yunnan Province of China. The disease resulted in up to 50% mortality in serious cases. Isolates from diseased plants grew 10.6 mm/day at 20°C on PDA. After 21 days, sclerotia were spherical to elliptical (0.4-2.5 × 0.3-1.8 mm). Conidia from diseased tissues were hyaline to pale brown, long, ovoid, unicellular, and measured 15.1-24.5 × 8.8-13.4 µm; conidiophores were 526-1,064 ×12-15 µm. Isolates did not form conidiophores or conidia on PDA or MYA. A phylogenetic analysis based on G3PDH, RPB2, and HSP60 sequence data supported assignment of three representative isolates as a new species of Botrytis. Based on morphological, phylogenetic characteristics and Koch's Postulates, the causal agent of gray mold on P. polyphylla was identified as a novel species, Botrytis polyphyllae.

[Key Bacteria for the Microbial Degradation of Pollutants in Cellar Water].

The study aimed to identify the key bacteria and the potential interactions among these bacteria during the degradation of pollutants in cellar water, The main pollution characteristics were nitrogen, phosphorus and organic pollution. The structure and function of the bacterial community and its correlation with water quality variables were analyzed. A network of seven associations of microbial co-occurrence was set up, based on 16S rRNA and the model for inferring co-occurrence or interspecific interactions of microbial species. This showed that there were a large number of microorganisms with relatively specific ecological functions in the cellar water, and that many metabolic activities were involved. The ecological relationships of most bacteria in the association network were a form of mutualism. The most prominent genera included Lacibacter, Arthrobacter, Candidatus Protochlamydia, Methylocaldum, Sulfuritalea, Mycobacterium, Aquirestis, Rhodobacter, and, Methylotenera. The strong associations were observed between following bacteria:Sulfuritalea-Rhodobacter, Azospirillum-Rhodobacter, Methylocaldum-Rhodobacter, Arthrobacter-Rhodobacter, Rhodoplanes-Rhodobacter, Candidatus Protochlamydia-Rhodobacter, Methylotenera-Rhodobacter, Rhodobacter-Aquirestis, Mycobacterium-Rhodobacter, Planctomyces-Candidatus Solibacter, Planctomyces-Legionella, Hymenobacter-Adhaeribacter, and Luteolibacter-Crenothrix. It was considered that Rhodobacter, Methylocaldum, Methylotenera, Acinetobacter, Novosphingobium, Planctomyces, Hymenobacter, and Luteolibacter were the key bacteria involved in microbial degradation of cellar water pollutants, and Rhodobacter was the representative genus of the key bacteria. The authors concluded that the research results improved understanding of the microbial degradation mechanism of pollutants in cellar water.

Genetic diversity and population structure of beet necrotic yellow vein virus in China.

Beet necrotic yellow vein virus (BNYVV) is a serious threat to the sugar beet industry worldwide. However, little information is available regarding the genetic diversity and population structure of BNYVV in China. Here, we analyzed multiple sequences from four genomic regions (CP, RNA3, RNA4 and RNA5) of a set of Chinese isolates. Sequence analyses revealed that several isolates were mixed infections of variants with different genotypes and/or different p25 tetrad motifs. In total, 12 distinct p25 tetrads were found in the Chinese BNYVV population, of which four tetrads were newly identified. Phylogenetic analyses based on four genes (CP, RNA3-p25, RNA4-p31 and RNA5-p26) in isolates from around the world revealed the existence of two to four groups, which mostly corresponded to previously reported phylogenetic groups. Two new subgroups and a new group were identified from the Chinese isolates in p25 and p26 trees, respectively. Selection pressure analysis indicated that there was a positive selection pressure on the p25 from the Chinese isolates, but the other three proteins were under a negative selection pressure. There was frequent gene flow between geographically distant populations, which meant that BNYVV populations from different provinces were not geographically differentiated.

[Regulatory effect of Astragalus membranaceus on the immune disorder in rats with IgA nephropathy].

OBJECTIVE: To study the regulattory effect of Astragalus membranaceus on immune disturbance of the rats with IgA nephropathy. METHODS: Rats IgA nephropathy (IgAN) model was duplicated by oral feeding of bovine serum albumin (BSA), subcutaneous injection of carbon tetrachloride (CCl4) and injection of lipopolysaccharide (LSP) into vena caudalis. The rats were divided into three groups randomly for the normal, IgAN model group and the group treated with Astragalus membranaceus (treatment group). The treatment group was given the Astragalus membranaceus granules via intragastric administratsion, the normal group and the IgAN model group were given the equal amount of aqua destillata by gastric perfusion. The rats were examined for albuminuria, hematuria and pathological changes of renal tissue and the distribution of TGF-beta and interleukin-5 in renal tissue was determined by immunohistochemistry and the IFN-gamma and IL-4 of cytokine of Th1 and Th2 types were detected in rats IgA nephropathy model by sandwich enzyme linked immunosorbent assay (ELISA). RESULTS: (1) The hematuria in rats with IgA nephropathy significantly increased compared with normal control group and Astragalus treatment group (P < 0.05). There was significant increase in albuminuria in rats with IgA nephropathy, compared with normal control group and astragalus treatment group (P < 0.01). (2) The pathological change of glomerular mesangium, renal tubules and renal interstitia became serious in rats IgA nephropathy model when compared with normal control group and astragalus treatment group. Immumofluorescence showed renal IgA density in rats IgA nephropathy model was significantly higher than that in the normal control group (P < 0.001) and astragalus treatment group (P < 0.001). (3) The result of immuno histochemistry showed that there was only weak expression of TGF-beta and interleukin 5 in normal renal tissue. The expression of TGF-beta and interleukin 5 in IgA nephropathy model was significantly stronger than those in normal control group (P < 0.05) and astragalus treatment group (P < 0.05). (4) The serum IL-4 levels were (33.74 +/- 7.52) pg/ml in rats IgA nephropathy model, significantly higher than that in normal control group (2.36 +/- 0.85) pg/ml and astragalus treatment group (3.24 +/- 1.13) pg/ml. The IFN-gamma level in serum of rats IgA nephropathy model was (18.79 +/- 3.80) pg/ml, which was significantly higher than that in normal control group (46.53 +/- 5.56) pg/ml and astragalus treatment group (41.28 +/- 2.95) pg/ml. CONCLUSIONS: The astragalus could lower the level of hematuria and 24 hours-albuminuria of the IgAN model, and amelioratse the change of the renal pathology and reduce the deposit of IgA in glomerular mesangium. The possible mechanism of the effect is that astragalus could regulate the derangement of Th1, Th2, accordingly could improve the level of IL-4 and IFN-gamma in the serum and diminish the expression of cytokine Th2 TGF-beta1 and IL-5 of the renal tissue, and thereby could postpone the development of IgAN.

[Pathogenicity of fungi isolated from American ginseng seeds and bioassay of fungicides against the pathogenic fungi].

OBJECTIVE: Detect the pathogenicity of fungi isolated from American ginseng seeds and select new fungicides against the pathogenic seed-born fungi. METHOD: inoculate the isolates to American ginseng seedlings to detect the pathogenicity, and seeded the hyphae disk at the center of agar plate containing chemicals to do fungicide bioassay. RESULT: Fusarium sp. isolate 5 and Alternara sp. isolate 13 had pathogenicity to American ginseng seedling. Sportak had the strongest inhibition to the two isolates, Carbendazim had better inhibition and Celest had weak inhibition. CONCLUSION: Sportak and Celest could be used as efficacious candidate chemicals to treat or coat the American ginseng seeds, and substitute Carbendazim, which has been used for many years, to control the diseases occurring in seedling stage of American ginseng.

[Biological effect of seed-coating in Carthamus tinctorins].

OBJECTIVE: To study the Biological effect of seed-coating in Carthamus tinctorins. METHOD: Two kinds of seedcoating chemicals SCF1 and SCF2 were used in this experiment, the seed YM-99 and 27981-99 were coated by three kinds of ratio of seedcoating chemicals to seed. It was investigated that the germination energy and germination percentage in the room and the emergence rate, seedling stage growing, pest in the field. RESULT: Seedoating can improve the emergence rate and seedling stage growing, it also can effectively control aphid, rust and virosis during the growing period in C. tinctorins. CONCLUSION: Seedcoating has significant biological effect in C. tinctorins.

[Fungal detection of American ginseng seeds from Beijing and northeast area in China].

OBJECTIVE: The quantity and genus of fungi on 13 samples of American ginseng seed from Beijing and Northeast area in China were detected. METHOD: Washing and surface sterilization were used to isolate the fungi existed on seed surface and inside of the seed, respectively. RESULT: The genera of the fungi in embryo and shell of the seeds mainly belonged to Fusarium spp., Alternaria spp., Penicilium spp., Cephalosporium sp., Rhizopus spp., and a small quantity of Mucor, Aspergillus, Tritroderma, Doratomyces and so on. The isolated fungal frequencies on the shell and in the embryo were 36%-100% and 40%-100% respectively. CONCLUSION: The fungal frequency of American ginseng seed was higher. There were significant differences among different seed samples, the main fungal genera and isolation frequency in the seed embryo were identical with the results from the seed shell.

[Investigation on occurrence of lycium pests and their natural enemies].

OBJECTIVE: To Provide the scientific basis for controlling the lycium pests. METHOD: The kinds and number of pests and their natural enemies were investigated at regular intervals and on the fixed trees. RESULT: There are 13 kinds of lycium pests and 17 kinds of natural enemies, the occurrence of which are closely related. CONCLUSION: Natural enemies can control aphids and psyllidae effectively, but ten-spotted lema and Epithrix sp. must be controlled by pesticides.