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  • Author: Yang Yang x
  • Life Sciences, other x
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Seasonal population dynamics of the monogeneans Pseudorhabdosynochus coioidesis and P. serrani on wild versus cultured groupers in Daya Bay, South China Sea

Abstract

In this paper, seasonal samples of wild versus cultured groupers, Epinephelus spp., from Daya Bay, South China Sea were examined to survey the seasonality of two important species, Pseudorhabdosynochus coioidesis and P. serrani (Monogenea: Diplectanidae), and to analyze the interspecific relationships between these two parasites. Between April 2008 and January 2009, P. coioidesis and P. serrani were found to be parasitic only on E. coioides Hamilton during summer and winter in the natural waters of Daya Bay, exhibiting a high degree of host specificity, whereas they co-occurred and persisted on several species of hosts, such as E. coioides, E. bruneus Block and E. awoara Temminck & Schlegel, in an experimental polyculture pond during several seasons. E. coioides is the main host for both of these two monogenean species. The overall prevalences and mean intensities of these two parasites on polycultured Epinephelus spp. showed the same pattern of seasonal fluctuations, with the maximum values during autumn, except for the overall prevalence of P. serrani, which reached its maximum values during summer and winter and the minimum values during spring and autumn. Prevalence and mean intensity were found to be related to host size. In the wild, medium-sized fishes harboured higher infections, whereas under cultured conditions the small-sized and large-sized fishes were more heavily infected. Simultaneous infections of P. coioidesis and P. serrani were common, and there was a significant positive interspecific correlation between these two parasites.

Open access
Exogenous isoleucine and phenylalanine interact with abscisic acid-mediated anthocyanin accumulation in grape

Abstract

Berry skin colour is a crucial determinant of red/black grape berry quality. We investigated the effects of combination treatments with amino acids and a low concentration of ABA on anthocyanin accumulation in grapes. Among the amino acids tested, isoleucine and phenylalanine resulted in high anthocyanin contents in grape cell cultures. The combination treatments with isoleucine or phenylalanine, and a low concentration of ABA enhanced anthocyanin accumulation in grape cells and detached grape berries. The combination treatment with isoleucine, but not with phenylalanine, and ABA upregulated MybA1 expression. Field-grown grapevines received combination treatments with isoleucine or phenylalanine, and ABA in two growing seasons. In the 2015 growing season, the combination treatments with isoleucine or phenylalanine, and a low concentration of ABA accelerated anthocyanin accumulation in grape berry skins of field-grown grapevines on days 10 and 31 post treatment. The effects on anthocyanin accumulation became negligible at harvest. The effect of the combination treatment with phenylalanine and a low concentration of ABA on anthocyanin accumulation was masked in the 2017 growing season due to the unexpected stimulation of anthocyanin accumulation by the low concentration of ABA, although the combination treatment accelerated anthocyanin accumulation on days 3 and 10 post treatment. Taken together, the results suggested that exogenous isoleucine and phenylalanine interacted with ABA-mediated anthocyanin accumulation in grape berry skins of field-grown grapevines when the activity of ABA used to treat the grapevines was inadequate.

Open access
The requirements of forestry cooperative organization development in China: a case study of different stakeholder groups

Abstract

After China’s collective forest tenure reform, cooperation organization has played an important role on the development of community forestry. In order to analyse the different stakeholders’ opinion and suggestion on the development of forestry cooperation organization, publicizing and training, participatory interview, brainstorming, and questionnaire surveys were used in this case study. According to the results it can be seen that the real motivation for the development of cooperatives is farmers’ demands and the demands come from farmers’ pursuit of interests in forest industry. Cooperatives in China are still in the early stage of development, and the cooperative laws cannot cover all the basic features of the forestry and the cooperatives. Therefore, the relevant laws and guarantee systems for resource exploitation and management, publicity and demonstration, forestry technology training as well as the preferential policies such as tax breaks, are needed for the sound development of China’s forestry cooperation organization.

Open access
Construction and analysis of a library of miRNA in gold-coloured mutant leaves of Ginkgo biloba L.

Abstract

To gain insights into the regulatory networks of miRNAs related to golden colour formation in Ginkgo biloba leaves, we constructed an sRNA library of golden-green striped mutant leaves. A total of 213 known miRNAs comprising 54 miRNA families were obtained, and 214 novel miRNAs were identified in the mutant leaves. We further constructed a normal green leaf sRNA library as a control and compared the expression of miRNAs between mutant and normal leaves. We found 42 known and 54 novel differential expression candidate miRNAs; 39 were up-regulated and 57 down-regulated in mutants compared to normal leaves. Our transcriptome analysis and annotation of the predicted targets indicated that the potential roles of miRNAs in G. biloba leaves included involvement in the ‘Glutathione metabolism’, ‘Plant circadian rhythm’, and ‘Phenylalanine metabolism’ categories. miRNAs and their targets were further validated by qRT-PCR. The expression of miR159a and miR159c, in particular, was significantly higher in mutant leaves than in normal leaves, while their potential target gene CLT3, which is associated with chloroplast development, displayed the opposite expression pattern. In addition, the expression of miR396g-3p and miR396h was also significantly higher in mutant leaves than in normal leaves, while the target genes ABP1 (auxin-related gene) and PPR32 (chloroplast RNA editing protein), respectively, showed the opposite expression pattern. Combined with the transcriptome analysis, these data suggest that miR159, miR396, and their targets may participate in chloroplast development and hormone metabolism to regulate colour formation in G. biloba leaves.

Open access
Morphological and molecular characterization of two isolates of Paratrichodorus porosus from Shenzhen, China

Abstract

Studies were conducted to characterize morphological and molecular profiles of two isolates of Paratrichodorus porosus (SZ1 and SZ2) which were recovered from Acacia mangium in Tianxinshan and Gleichenia linearis in Yangmeikeng environmental monitoring sites in Shenzhen, China, respectively. Analysis of morphometric, morphological and molecular characters revealed these two Shenzhen isolates are identical to P. porosus. Measurements of both study isolates lie within the ranges for P. porosus. It is typologically characterized by possessing a clearly swollen body cuticle after fixation, an onchiostyle ventrally curved, 46–58 μm long, a pharyngeal bulb usually with a well developed anterior-dorsal intestinal overlap, a secretoryexcretory pore opening between the nerve ring and anterior end of pharyngeal bulb, 90–110 μm from the anterior end, a reproductive system with didelphic, amphidelphic, without spermathecae, a pore-like vulva in ventral view and occupying 52.0 %–59.5 % of total body length from anterior end, a short and barrel-shaped vagina with small sclerotizations, a pair of ventromedian advulvar body pores located prevulvar and postvulvar, a rounded tail and a subterminal anus in females. The sequence analysis based on partial rDNA 18S gene and 28S D2/D3 expansion segment confirm its identity as P. porosus. This is the first report of P. porosus associated with A. mangium and G. linearis.

Open access