Comparative analyses of the mitochondrial genomes of the cattle tick Rhipicephalus microplus clades A and B from China.

The cattle tick (Rhipicephalus microplus) is one of the most common ticks parasitizing livestock, causing diseases as the vector of pathogens. In this study, we amplified and sequenced the complete mitochondrial (mt) genome of R. microplus from Hainan province of China and compared it with that of R. microplus from Guizhou province of China. The mt genome sequence of R. microplus from Hainan isolate was 15,163 bp in size, which was significantly longer (299 bp) than R. microplus from Guizhou isolate. Nucleotide sequence difference in the entire mt genome except for non-coding region was 5.6% between R. microplus from Hainan and Guizhou isolates. For the 13 protein-coding genes, this comparison revealed the sequence differences of nucleotide (3.8-10.1%) and amino acid (1.2-17.3%). Phylogenetic analysis of R. microplus indicated that R. microplus from Hainan isolate clustered in clade A, and R. microplus from Guizhou isolate clustered in clade B. Taken together, the findings support the recent proposal the existence of two lineages (clades A and B) of R. microplus in China.

Novel genotypes and multilocus genotypes of Enterocytozoon bieneusi in two wild rat species in China: potential for zoonotic transmission.

Enterocytozoon bieneusi is an opportunistic pathogen in immunodeficient patients. Although this pathogen has been reported in many domestic animals, few data are available about the occurrence of E. bieneusi in wild rats. In the current study, a total of 228 fecal samples from two wild rat species (Leopoldamys edwardsi and Berylmys bowersi) in China were examined by a nested PCR-based sequencing approach employing the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The overall prevalence of E. bieneusi in wild rats was 33.3% (76/228), with 35.1% (39/111) in L. edwardsi and 31.6% (37/117) in B. bowersi. Ten E. bieneusi genotypes (including four known and six novel genotypes) were identified, with the novel CQR-2 (n = 15) as the predominant genotype. Phylogenetic analysis indicated that ten genotypes in the present study belong to zoonotic group 1, which contains many genotypes in humans. Furthermore, multilocus sequence typing (MLST) analysis showed that 19 ITS-positive samples were successfully amplified at three microsatellites and one minisatellite, forming 18 multilocus genotypes (MLGs). This is the first report of E. bieneusi infection in the wild rats L. edwardsi and B. bowersi. Our findings suggest that wild rats could be a significant source of human infection, including contaminated food and water.

[Response of growth and photosynthetic characteristics of Polygonatum cyrtonema to shading conditions].

The purpose of this experiment was to study the effects of different shading conditions on the growth,physiological characteristics and biomass allocation of Polygonatum cyrtonema,which offered a theoretical basis for its cultivation.Different light environments(100%,80%,60% and 35% light transmittance) were simulated with shading treatments.Growth and photosynthetic indexes of P.cyrtonema were measured and the variances were analyzed.The results show that shading decreased superoxide anion radical(O-·2)production rate and hydrogen peroxide(H_2O_2) accumulation,kept the activity of SOD,POD and CAT enzyme at a high level.Furthermore,The content of chlorophyll a and chlorophyll b,net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximal photochemical efficiency of photosystem Ⅱ(Fv/Fm),photochemical quenching index(q P) and effective quantum yield of photosystem II(ΦPSⅡ) of P.cyrtonema were increased while the intercellular CO2 concentration(Ci),Foand NPQ were decreased by shading.Shading is beneficial to P.cyrtonema growth,can increase the total biomass P.cyrtonema.The allocation proportion of biomass on the aerial portion of P.cyrtonema increased but underground parts decreased with increasing shading conditions.In this study,P.cyrtonema can grow well in shading conditions,shading is beneficial to the formation of the yield and quality of the rhizomes of P.cyrtonema,especially in 65% light transmittance.

[Effects of N and Zn interaction on growth, yield and active components of Agastache rugosa].

The study is aimed to explore the effect of combination use of nitrogen(N) and zinc(Zn) fertilizers on the growth, yield and the effective components of Agastache rugosa. A. rugosa was grown under two N application rate (120, 300 kg·hm⁻²) and five Zn levels (0, 20, 50, 100，150 kg·hm⁻²) under field condition. The effect of the treatments on the physiological indicators, distribution of nitrogen and zinc and volatile oil components of A. rugosa were studied. The results showed that the combination use of N and Zn could significantly affect the growth and development, yield and volatile oil components of A. rugosa. Under the test conditions, the highest yield of Agastaches Herba was obtained when 50 kg·hm⁻² of Zn fertilizer was applied with high N application rate of 300 kg·hm⁻². Under the same N application rate, the increase of Zn production was positively correlated with the amount of Zn application in a certain concentration range, but excessive Zn application led to the decrease of yield. With the increase of N application level, the content of Zn also significantly increased. The combination use of N and Zn increased the yield of Agastaches Herba. High level of N application was beneficial to the absorption and accumulation of N and Zn of A. rugosa. Zn fertilizer could also promote the absorption and accumulation of N of A. rugosa. The interaction between N and Zn had significant influence on the main chemical constituents of the volatile oil of A. rugosa. Among the volatile oil chemical constituents of A. rugosa the content of pulegone (34.56%-53.91%) and piperonyl methyl ether (18.86%-42.27%) were much higher. Under the same N application rate, different Zn application rates also had significant effects on the main chemical components of volatile oil.

Molecular Prevalence and Genetic Characterization of Toxoplasma gondii in Wild Birds in Hunan Province, China.

Toxoplasma gondii is a ubiquitous apicomplexan parasite of warm-blooded animals and humans. However, limited information is available about T. gondii infection in wild birds. In this study, 239 wild birds were collected from Hunan province of China, including 38 chestnut bunting, 44 olive-backed pipit, 26 yellow-breasted bunting, and 131 tree sparrows. Genomic DNA of brain tissues were extracted and assayed by B1 gene, and the positive samples were genotyped at 10 genetic markers [SAG1, SAG2 (5'+3' SAG2, alter. SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico] using multilocus nested-PCR-restriction fragment length polymorphism technology. The results showed that 13 (5.51%) of the 239 wild birds were positive for T. gondii. Among them, three samples have completely genotyped at all loci, and were identified as ToxoDB #10. Our results have indicated that wild birds can carry and potentially disseminate the T. gondii. This is the first report of the molecular prevalence and genetic characterization of T. gondii in wild birds in Hunan province, China. Further research should be investigated to understand weather T. gondii can be transmitted from wild birds to other animals or humans.