First Report of Rhizoctonia solani AG-2-2 IIIB Causing Foliar Blight on Bletilla striata in China.

Bletilla striata (Thunb.) Rchb. f. (Orchidaceae), a perennial plant, is a traditional Chinese herb (known as baiji) used to treat hemorrhage, scalding injuries, gastric ulcers, pulmonary diseases, and inflammation (Zu et al. 2019). In May 2019, foliar blight symptoms were observed on approximately 25% of B. striata (cv. Guiji No.1) plants in three plantations (∼4.5 hectares in total) in Ziyuan County, Guangxi Province, China. Initial symptoms were light brown, irregular, water-soaked spots on the plant leaves. Several spots often merged, forming large, irregular, lesions that extended onto the stem after a week and led to leaf abscission, and even plant death. To determine the causal agent, 5-mm squares cut from the margin of 6 infected leaves were surface disinfected in 1% sodium hypochlorite solution for 2 min, rinsed three times with sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 28°C (12-h light-dark cycle) for 3 days. The emerging hyphal tip of a single mycelium was transferred to PDA to obtain pure cultures of the isolates. Twenty isolates were obtained, and 10 isolates (50%) were initially white before turning light brown (∼4 days). Septate hyphae were 4.29 to 10.75 µm (average 6.42 µm) in diameter and branched at right angles with a constriction at the origin of the branch point. Staining with 1% safranin O and 3% KOH solution (Bandoni 1979) revealed multinucleated cells (3 to 9 nuclei per cell, n = 142). This morphology was typical of Rhizoctonia solani Kühn (Meyer et al. 1990). For species confirmation by molecular identification, three isolates (BJ101.6, BJ101.11, and BJ102.2) were cultured on PDA for 4 days, then DNA was extracted from the mycelium using the CTAB method (Guo et al. 2000), and the ribosomal ITS1-5.8S-ITS2 region was amplified by PCR using the universal fungal primers ITS1 and ITS4 (White et al. 1990). Internal transcribed spacer (ITS) sequences of strains BJ101.6, BJ101.11, and BJ102 (deposited in GenBank under accession nos MT406271, MT892815, and MT892814, respectively) had over 99% similarity with those of R. solani AG-2-2 IIIB in GenBank (accession nos JX913810 and AB054858) (Carling et al. 2002; Hong et al. 2012). Phylogenetic analysis using ITS sequences showed that the isolates clustered monophyletically with strains of R. solani AG-2-2 IIIB. The AG of the isolates was confirmed by their ability to grow well on PDA at 35°C, which separates AG-2-2 IIIB from AG-2-2 IV (Inokuti et al. 2019). Based on morphological characteristics and nucleotide sequence analysis, the isolates were identified as R. solani AG-2-2 IIIB. Pathogenicity was tested using 1.5-year-old B. striata (cv. Guiji No.1) plants grown in a perlite and peat moss mixture (1:3) in 7-cm pots. Healthy leaves on plants were inoculated with an aqueous suspension (approximately 1 × 105 hyphal fragments/mL, 100 µL) prepared from cultures of strains BJ101.6, BJ101.11, and BJ102.2, each isolate was inoculated onto three plants; three other plants with sterile water served as controls. All plants were enclosed in transparent plastic bags and incubated in a greenhouse at 28°C for 14 days (12-h photoperiod). Three days post-inoculation, leaves exposed to the mycelial fragments had symptoms similar to those originally observed in the field. No symptoms were detected on control plants. Experiments were replicated three times with similar results. To fulfill Koch's postulates, R. solani AG-2-2 IIIB was re-isolated on PDA from symptomatic leaves and confirmed by sequencing, whereas no fungus was isolated from the control plants. To our knowledge, this is the first report of R. solani AG-2-2 IIIB causing foliar blight on B. striata in China, and these findings will be useful for further control strategies and research.

A facile heterogeneous system for persulfate activation by CuFe2O4 under LED light irradiation.

In this study, the removal performance for rhodamine B (RB) by persulfate (PS) activated by the CuFe2O4 catalyst in a heterogeneous catalytic system under LED light irradiation was investigated. The effect of vital experimental factors, including initial solution pH, CuFe2O4 dosage, PS concentration, co-existing anion and initial RB concentration on the removal of RB was systematically studied. The removal of RB was in accordance with the pseudo first-order reaction kinetics. Over 96% of 20 mg L-1 RB was removed in 60 min using 0.5 g L-1 CuFe2O4 catalyst and 0.2 mM PS at neutral pH. In addition, free radical quenching experiments and electron spin resonance (EPR) experiments were performed, which demonstrated the dominant role of sulfate radical, photogenerated holes and superoxide radical in the CuFe2O4/PS/LED system. The morphology and physicochemical properties of the catalyst were characterized by XRD, SEM-EDS, TEM, N2 adsorption-desorption isotherm, UV-vis DRS, and XPS measurements. Moreover, 18.23% and 38.79% total organic carbon (TOC) removal efficiency was reached in 30 min and 60 min, respectively. The catalyst revealed good performance during the reusability experiments with limited iron and copper leaching. Eventually, the major intermediates in the reaction were detected by GC/MS, and the possible photocatalytic pathway for the degradation of RB in the CuFe2O4/PS/LED system was proposed. The results suggest that the CuFe2O4/PS/LED system has good application for further wastewater treatment.

[Observation of the clinical efficacy of the bone filling bag vertebroplasty for the treatment of osteoporotic vertebral compression fractures].

OBJECTIVE: To explore the clinical effects of bone filling bag vertebroplasty in treating osteoporotic vertebral compression fractures. METHODS: The clinical data of 127 patients (145 vertebrae) with osteoporotic vertebral compression fractures who corresponded the criteria of inclusion and exclusion from December 2015 to June 2017 were retrospectively analyzed. Responsible vertebral bodies were identified by clinical situation, X-rays, CT scan, MRI. Among them, 95 cases (110 vertebrae) were treated by percutaneons kyphoplasty (PKP group), there were 34 males (42 vertebrae) and 61 females (68 vertebrae), with an average age of (73.92±7.14) years, 47 thoracic vertebra (T8-T12) and 63 lumbar vertebra (L1-L5). Other 32 patients (35 vertebrae) were treated by bone filling bag vertebroplasty(bone filling bag vertebroplasty group). There were 11 males (12 vertebrae) and 21 females (23 vertebrae), with an average age of (71.56±7.89) years, 16 thoracic vertebra (T9-T12) and 19 lumbar vertebra(L1-L5). Postoperative pain after 3 days, vertebral body height, improvement of lumbar function were recorded and bone cement diffusion and leakage were observed by X-rays. RESULTS: All operations were successful and no complications were found. In bone filling bag vertebroplasty group, operation time was (31.75±4.99) min, postoperative VAS score at 3 days was(2.38±0.94) points, anterior and middle height of the vertebral body were(19.54±2.36) mm and (18.16±2.65) mm, respectively; ODI score was(25.19±5.49) points, all above items after operation were better than preoperation(P<0.01), but there was no significant difference between two groups(P>0.05). Bone cement was patchy, clumpy or slightly dispersed by X-rays at 3 days after operation, the leakage rate of bone cement in bone filling bag vertebroplasty group was 2.86%(1/35), while was 6.36%(18/110) in PKP group, all of them were "trailing sign", there was significant difference between two groups (P<0.05). CONCLUSIONS: The clinical effect of bone filling bag vertebroplasty in the treatment of osteoporotic vertebral compression fractures is similar to percutaneous kyphoplasty, it can effectively relieve the pain, restore part vertebral body height and obviously reduce the leakage rate, with safer, it is a simple, rapid and effective therapeutic method.

[Effects of different treatments on patients with osteoporotic fracture after percutaneous kyphoplasty].

OBJECTIVE: To evaluate effects of different treatments on patients with osteoporotic vertebral fracture after percutaneous kyphoplasty in pain and function. METHODS: From March 2010 to March 2012,138 patients (165 vertebrae) with thoracic and lumbar vertebral osteoporotic fracture were randomly divided into three groups (control group, treatment group and comprehensive group), 46 cases in each group, and all patients were treated by PKP. Control group were treated with calcium and calcitriol after operation, treatment group added salmon calcitonin see calcimar based on control group, comprehensive group added incrementality waist musculi dorsi function exercise based on treatment group. VAS, ODI scores and BMD before operation, 3 d, 2 weeks, 1 month, 6 months and 12 months after operation were detected and compared. RESULTS: All operation were performed successfully,38 cases (45 vertebrae) in control group, 36 cases (44 vertebrae) in treatment group and 40 cases (49 vertebrae) were obtained complete following up, there was no significant meaning in following time among three groups (P>0.05). Postoperative VAS and ODI scores at 3 d, 2 weeks and 1 month among three groups were lower than that of before operation (P<0.01). Compared with control group, postoperative VAS score at 3 d, 2 weeks and 1 month were decreasedin treatment group and comprehensive group, but there was no significant meaning in ODI scores (P>0.05). At 6 and 12 months after operation,there was no significant differences in VAS and ODI between control group and treatment group (P>0.05), while VAS score in comprehensive group decreased much than other two groups,decreased continuously (P<0.01). At 12 months after operation, BMD among three groups were increased more than preoperative,and BMD in comprehensive group was more obviously than that of in control and treatment group. CONCLUSION: PKP, an effective method for the treatment of thoracic and lumbar vertebral osteoporotic fracture, could improve short-term clinical effects by adding calcitonin with calcium supplements and activated vitamin D. Waist musculi dorsi function exercise could improve long-term clinical effects of PKP and improve quality of life.