The interactive effects of arbuscular mycorrhiza and plant growth-promoting rhizobacteria synergistically enhance host plant defences against pathogens

Belowground interactions between plant roots, mycorrhizal fungi and plant growth-promoting rhizobacteria (PGPR) can improve plant health via enhanced nutrient acquisition and priming of the plant immune system. Two wheat cultivars differing in their ability to form mycorrhiza were (co)inoculated with the mycorrhizal fungus Rhizophagus irregularis and the rhizobacterial strain Pseudomonas putida KT2440. The cultivar with high mycorrhizal compatibility supported higher levels of rhizobacterial colonization than the low compatibility cultivar. Those levels were augmented by mycorrhizal infection. Conversely, rhizobacterial colonization of the low compatibility cultivar was reduced by mycorrhizal arbuscule formation. Single inoculations with R. irregularis or P. putida had differential growth effects on both cultivars. Furthermore, while both cultivars developed systemic priming of chitosan-induced callose after single inoculations with R. irregularis or P. putida, only the cultivar with high mycorrhizal compatibility showed a synergistic increase in callose responsiveness following co-inoculation with both microbes. Our results show that multilateral interactions between roots, mycorrhizal fungi and PGPR can have synergistic effects on growth and systemic priming of wheat

Management of Soil-Borne Diseases of Grain Legumes Through Broad-Spectrum Actinomycetes Having Plant Growth-Promoting and Biocontrol Traits

Chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan L.) are the two important grain legumes grown extensively in the semiarid tropics (SAT) of the world, where soils are poor in nutrients and receive inadequate/erratic rainfall. SAT regions are commonly found in Africa, Australia, and South Asia. Chickpea and pigeonpea suffer from about 38 pathogens that cause soil-borne diseases including wilt, collar rot, dry root rot, damping off, stem canker, and Ascochyta/Phytophthora blight, and of which three of them, wilt, collar rot, and dry root rot, are important in SAT regions. Management of these soil-borne diseases are hard, as no one control measure is completely effective. Advanced/delayed sowing date, solarization of soil, and use of fungicides are some of the control measures usually employed for these diseases but with little success. The use of disease-resistant cultivar is the best efficient and economical control measure, but it is not available for most of the soil-borne diseases. Biocontrol of soil-borne plant pathogens has been managed using antagonistic actinobacteria, bacteria, and fungi. Actinobacterial strains of Streptomyces, Amycolatopsis, Micromonospora, Frankia, and Nocardia were reported to exert effective control on soil-borne pathogens and help the host plants to mobilize and acquire macro- and micronutrients. Such novel actinomycetes with wide range of plant growth-promoting (PGP) and antagonistic traits need to be exploited for sustainable agriculture. This chapter gives a comprehensive analysis of important soil-borne diseases of chickpea and pigeonpea and how broad-spectrum actinomycetes, particularly Streptomyces spp., could be exploited for managing them

Multiple Mechanisms of Enterobacter asburiae strain RS83 for Plant Growth Enhancement

Enterobacter asburiae strain RS83 having the capacity of promoting plant growth and yield of various vegetable crops was isolated from the rhizosphere of cassava in Phitsanulok province. The objective of this study was to investigate possible bacterial determinants of strain RS83 involved with plant growth enhancement. Different methods such as using specific media, biochemical tests and high performance liquid chromatography technique were used to analyze bacterial determinants of interest relevant to plant growth promotion. Results revealed several bacterial determinants of strain RS83 implicated in plant growth improvement. These determinants released from strain RS83 included indole-3 acetic acid (IAA; plant-hormone like), catechol siderophore enterobactin (iron-chelating agent), and gluconic acid relating to phosphate solubilization. Moreover, the presence of pellicles in a semi-solid nitrogen-free medium inoculated with strain RS83 indicated possible nitrogen-fixing capacity of the bacterium. In conclusion, strain RS83 possesses several bacterial determinants involved with plant growth promotion

Physicians´ generic drug prescribing behavior in district hospitals: a case of Phitsanulok, Thailand

Generic prescribing is a sound approach to contain health care costs. However, little is known about physicians´ prescribing patterns in the Thai context. Objective: To explore physicians´ generic prescription patterns in district hospitals. Methods: Data was collected from three of the eight district hospitals between January and December 2008 (final response rate 37.5%). All participating hospitals were between 30 and 60-bed capacity. The researchers reviewed 10% of total outpatient prescriptions in each hospital. Results: A total of 14,500 prescriptions were evaluated. The majority of patients were under universal health coverage (4,367; 30.1%), followed by senior citizens´ health insurance (2,734; 18.9%), and civil servant medical benefit schemes (2,419; 16.7%). Ten thousand six hundred and seventy-one prescriptions (73.6% of total prescriptions) had at least one medication. Among these, each prescription contained 2.85 (SD=1.69) items. The majority of prescriptions (7,886; 73.9%) were prescribed by generic name only. Drugs prescribed by brand names varied in their pharmacological actions. They represented both innovator and branded-generic items. Interestingly, a large number of them were fixed-dose combination drugs. All brand name prescriptions were off patented. In addition, none of the brand-name drugs prescribed were categorized as narrow therapeutic range or any other drug that had been reported to have had problems with generic substitution. Conclusion: The majority of prescriptions in this sample were written by generic names. There is room for improvement in brand name prescribing patterns.La prescripción genérica es algo que podría contener los costes sanitarios. Sin embargo, se sabe poco de los hábitos de prescripción genérica de los médicos tailandeses. Objetivo. Explorar los hábitos de prescripción genérica de los médicos en hospitales distritales. Métodos. Se recogieron datos de tres de los ocho hospitales de distrito entre enero y diciembre de 2008 (tasa final de respuesta 37,5%). Todos los hospitales participantes estaban entre 30 y 60 camas de capacidad. Los investigadores revisaron el 10% del total de las prescripciones ambulatorias de cada hospital. Resultados. Se evaluó un total de 14500 prescripciones. La mayoría de los pacientes estaban bajo la cobertura sanitaria universal (4367; 30,1%) seguidos del seguro de ciudadanos mayores (2734; 18,9%) y de los sistemas de funcionarios civiles (2419; 16,7%). 10671 prescripciones (73,6% del total de prescripciones) tenían al menos un medicamento. Entre estas, cada prescripción contenía 2,85 (DE=1,69) ítems. La mayoría de las prescripciones (7886; 73,9%) estaban escritas en nombre genérico solamente. Los medicamentos prescritos por marca comercial variaban en sus acciones farmacológicas. Estos representaban tanto ítems innovadores como genéricos con marca. Curiosamente, un gran número de ellos eran combinaciones a dosis fijas. Todas las prescripciones por marca eran medicamentos con patente caducada. Además, ninguna de las marcas prescritas estaba calificada de estrecho margen terapéutico u otros medicamentos que hayan comunicado problemas con la sustitución genérica. Conclusión. La mayoría de las prescripciones en esta muestra estaban escritas en nombres genéricos. Existe espacio para mejorar los patrones de prescripción por marcas

“Rhizoproduct”, a biofertilizer containing spores of Bacillus cereus strain RS87 for early rice seedling enhancement and with potential for partial fertilizer substitution

The objectives of this study were to investigate the seed to seedling enhancement of Rhizo-product under laboratory conditions and to explore the efficacy of the product for partial fertilizer substitution in rice growth and yield production under submerged soil. Results showed that rice seedlings treated with Rhizo-product was significantly promoted compared to the non-bacterized control. Greenhouse experiments revealed that the growth parameters of all rice cultivars treated at 50% recommended fertilizer rate (RFR) and supplemented with Rhizo-product were better than, or equal to, the growth parameters of rice plants treated with full fertilizer rate (FFR) alone. Additionally, yield production of all rice cultivars receiving 50% RFR supplemented with the product was similar to rice treated with FFR alone. In conclusion, Rhizo-product stimulated early rice seed to seedling growth and exhibited growth and yield production at 50% RFR that was comparable to growth and yield production at FFR