Radix pseudostellariae L. is a common and popular Chinese medication. However, continuous monoculture has increased its susceptibility to severe diseases. We identified two pathogenic microorganisms, Talaromyces helicus M. (KU355274) and Kosakonia sacchari W. (KU324465), and their antagonistic bacterium, Bacillus pumilus Z. in rhizosphere soil of continuously monocultured R. pseudostellariae. Nine types of phenolic acids were identified both in the rhizosphere soil and in culture medium under sterile conditions. A syringic acid and phenolic acid mixture significantly promoted the growth of T. helicus and K. sacchari. T. helicus could utilize eight types of phenolic acids, whereas K. sacchari could only use four phenolic acids. K. sacchari produced protocatechuic acid when consuming vanillin. Protocatechuic acid negatively affected the growth of B. pumilus. The 3A-DON toxin produced by T. helicus promoted the growth of K. sacchari and inhibited growth of B. pumilus at low concentrations. These data help explain why phenolic exudates mediate a microflora shift and structure disorder in the rhizosphere soil of continuously monocultured R. pseudostellariae and lead to increased replanting disease incidence.
BackgroundAs the core of the county-level Maternal and Child Health Hospitals (MCHH) in rural areas of China, the service efficiency affects the fairness and availability of healthcare services. This study aims to identify the determinants of hospital efficiency and explore how to improve the performance of MCHH in terms of productivity and efficiency.MethodsData was collected from a sample of 32 county-level MCHHs of Guangxi in 2014. Firstly, we specified and measured the indicators of the inputs and outputs which represent hospital resources expended and its profiles respectively. Then we estimated the efficiency scores using Data Envelopment Analysis (DEA) for each hospital. Efficiency scores were decomposed into technical, scale and congestion components, and the potential output increases and/or input reductions were also estimated in this model, which would make relatively inefficient hospitals more efficient. In the second stage, the estimated efficiency scores are regressed against hospital external and internal environment factors using a Tobit model. We used DEAP (V2.1) and R for data analysis.ResultsThe average scores of technical efficiency, net technical efficiency (managerial efficiency) and scale efficiency of the hospitals were 0.875, 0.922 and 0.945, respectively. Half of the hospitals were efficient, and 9.4 % and 40.6 % were weakly efficient and inefficient, respectively. Among the low-productiveness hospitals, 61.1 % came from poor counties (Poor counties in this article are in the list of key poverty-stricken counties at the national level, published by The State Council Leading Group Office of Poverty Alleviation and Development, 2012). The total input indicated that redundant medical resources in poverty areas were significantly higher than those in non-poverty areas. The Tobit regression model showed that the technical efficiency was proportional to the total annual incomes, the number of discharge patients, and the number of outpatient and emergency visits, while it was inversely proportional to total expenditure and the actual number of open beds. Technical efficiency was not associated with number of health care workers.ConclusionThe overall operational efficiency of the county-level MCHHs in Guangxi was low and needs to be improved. Regional economic differences affect the performances of hospitals. Health administrations should adjust and optimize the resource investments for the different areas. For the hospitals in poverty areas, policy-makers should not only consider the hardware facilities investment, but also the introduction of advanced techniques and high-level medical personnel to improve their technical efficiency.
Under consecutive monoculture, the abundance of pathogenic fungi, such as Fusarium oxysporum in the rhizosphere of Radix pseudostellariae, negatively affects the yield and quality of the plant. Therefore, it is pertinent to explore the role of antagonistic fungi for the management of fungal pathogens such as F. oxysporum. Our PCR-denatured gradient gel electrophoresis (DGGE) results revealed that the diversity of Trichoderma spp. was significantly declined due to extended monoculture. Similarly, quantitative PCR analysis showed a decline in Trichoderma spp., whereas a significant increase was observed in F. oxysporum. Furthermore, seven Trichoderma isolates from the R. pseudostellariae rhizosphere were identified and evaluated in vitro for their potentiality to antagonize F. oxysporum. The highest and lowest percentage of inhibition (PI) observed among these isolates were 47.91 and 16.67%, respectively. In in vivo assays, the R. pseudostellariae treated with four Trichoderma isolates, having PI > 30%, was used to evaluate the biocontrol efficiency against F. oxysporum in which T. harzianum ZC51 enhanced the growth of the plant without displaying any disease symptoms. Furthermore, the expression of eight defense-related genes of R. pseudostellariae in response to a combination of F. oxysporum and T. harzianum ZC51 treatment was checked, and most of these defense genes were found to be upregulated. In conclusion, this study reveals that the extended monoculture of R. pseudostellariae could alter the Trichoderma communities in the plant rhizosphere leading to relatively low level of antagonistic microorganisms. However, T. harzianum ZC51 could inhibit the pathogenic F. oxysporum and induce the expression of R. pseudostellariae defense genes. Hence, T. harzianum ZC51 improves the plant resistance and reduces the growth inhibitory effect of consecutive monoculture problem.
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