ABSTRACT
Star anise (Illicium verum) is an important economic and medical plant widely cultivated in Guangxi province, China. Its fruit can be used as spice and medicine (Wang et al. 2011). In recent years, anthracnose led to a serious decline in the production of star anise in Guangxi. In 2021, a survey conducted in CenwangLaoshan Reserve of Guangxi (24°21'N; 106°27'E) showed that the 2500 ha planting area had disease incidence greater than 80%. The leaf symptoms initially appeared as small spots, then expanded to round spots, finally becoming withered with grayish-white centers, surrounded by dark brown margins. Sometimes, small black acervuli were observed in the later stage. To explore the pathogen, infected leaves were collected and cut into small pieces (about 5 mm2) from the edge of the lesion, disinfected with 75% ethanol for 10 s, 1% NaClO for 1 min, washed with sterilized water and incubated on potato dextrose agar (PDA) plates at 28 °C in the dark. Ten single-spore isolates were obtained from the cultures. After 7 days on PDA at 28 °C, the colonies of 7 isolates were white with abundant aerial hyphae, gray-black with white-gray margins, and the other 3 isolates were light gray on the upper surface, and pink or orange on the underside. Representative isolates BS3-4 and BS3-1 were selected from 3 isolates and 7 isolates, respectively. Conidia of BS3-4 and BS3-1 were both hyaline, cylindrical, aseptate, smooth, apex obtuse, base truncate, and no significant differences (P > 0.05) in size between BS3-1 (13.22 to 5.38 × 3.89 to 1.99 µm) (n = 50) and BS3-4 (12.04 to 4.34 × 3.48 to 1.64 µm) (n = 50). These morphological characteristics were consistent with the Colletotrichum ssp. (Damm et al. 2012). The species identification of BS3-4 and BS3-1 was performed based on DNA sequence analysis. Genomic DNA was extracted as a template. Partial sequences of the rDNA internal transcribed spacer (ITS), actin gene (ACT), ß-tubulin2 (TUB2) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were amplified and sequenced (Weir et al. 2012). The sequences were deposited in GenBank (ITS:OQ062642-43; ACT:OQ067614-15; GAPDH:OQ067616-17;TUB2ï¼OQ067618-19). Based on the concatenated sequences of the 4 genes (ITS-ACT- GAPDH -TUB2) of BS3-4 and BS3-1 as well as sequences of other Colletotrichum spp. obtained from GenBank, the Maximum likelihood (ML) tree which produced with IQ-TREE (Minh et al. 2020) revealed that the isolate BS3-1 was Colletotrichum horii, and BS3-4 was Colletotrichum fioriniae. Pathogenicity was confirmed on healthy leaves of 1-year-old star anise seedlings (cultivar Dahong), and the leaves were wounded by sterilized toothpicks, and were inoculated with 10 µl of conidial suspensions of BS3-1 and BS3-4 (106 conidia/ml). Control seedlings were inoculated with sterilized distilled water. Five leaves per plant and 3 plants per treatment were selected. All inoculated seedlings were maintained in the greenhouse (12/12h light/dark, 25 ± 2â, 90% relative humidity). Wound sites inoculated with BS3-1 and BS3-4 both turned greenish-brown after 2 days and then turned light brown with water-soaked spots. Black (BS3-1) or orange (BS3-4) dots of acervuli developed after 6 days. The lesion diameter of BS3-1 (14.4 mm) was larger than that of BS3-4 (8.1 mm). No symptoms were observed on controls. BS3-1 and BS3-4 were re-isolated from inoculated leaves, fulfilling Koch's postulates. Anthracnose of star anise caused by C.horii has been reported in China (Liao et al. 2017). However, to our knowledge, this is the first report of C.fioriniae infecting star anise in China. Accurate pathogen identification in this study could provide a reference for the control of anthracnose on star anise.
ABSTRACT
Economic development, accompanying with environmental damage and energy depletion, becomes essential nowadays. There is a complicated and comprehensive interaction between economics, environment and energy. Understanding the operating mechanism of Energy-Environment-Economy model (3E) and its key factors is the inherent part in dealing with the issue. In this paper, we combine System Dynamics model and Geographic Information System to analyze the energy-environment-economy (3E) system both temporally and spatially, which explicitly explore the interaction of economics, energy, and environment and effects of the key influencing factors. Beijing is selected as a case study to verify our SD-GIS model. Alternative scenarios, e.g., current, technology, energy and environment scenarios are explored and compared. Simulation results shows that, current scenario is not sustainable; technology scenario is applicable to economic growth; environment scenario maintains a balanced path of development for long term stability. Policy-making insights are given based on our results and analysis.
Subject(s)
Economic Development , Models, Theoretical , Beijing , Geographic Information Systems , Models, EconomicABSTRACT
AIM: To develop a double mAb sandwich ELISA for detecting sCD226 and apply it to clinical specimens. METHODS: The optimal concentrations of coating mAb and HRP-mAb, and the optimal diluents were determined. A double mAb sandwich ELISA then was established. The specificity, sentivity and stability of the method were identified. And clinical specimens were detected by this method. RESULTS: The optimal concentrations of coating mAb LeoA1 and HRP-mAb FMU3 were 2.5 mg/L and 1:400, respectively, and the optimal diluents for standard antigen and HRP-mAb were 1 g/L BSA 1 mL/L Tween20-PBS and 30 g/L PEG-PBS.The ELISA achieved satisfactory results in respect to specificity (no cross-reaction to human IgG, in block test blocking effect was does-dependent), sensitivity (the detected threshold was 110 ng/L) and stability (CV<10.2%). Statistical analysis showed that the serum sCD226 level in patients with rheumatoid arthritis (RA) was significantly higher than that in healthy adults. CONCLUSION: A double mAb sandwich ELISA with high specifity, and relative sensitivity for detection of sCD226 has been developed. It is shown to be an applicable method of detecting sCD226 in clinical specimens.
