Arbuscular mycorrhizae fungi a potential eco-friendly tool for sustainable agriculture under changing climatic conditions/ in biotic and abiotic stress conditions

Los hongos micorrízicos arbusculares (HMA) son biotrofos obligados que viven en asociación simbiótica con las raíces de las plantas. Se encuentran entre los microorganismos del suelo más extendidos que proporcionan a la planta huésped nutrientes y protección contra patógenos. Las prácticas agrícolas modernas, como la labranza frecuente, el alto empleo de fertilización inorgánica pesticidas junto con condiciones climáticas cambiantes debido al calentamiento global, tienen enormes impactos en la colonización de los HMA, la interacción con las plantas y la productividad de los cultivos. Los HMA afectan positivamente la tolerancia de las plantas al estrés biótico y abiótico, a los ecosistemas severos y sus patógenos al alterar la estructura de las raíces, la exudación, la microflora de la rizosfera, la producción de antifúngicos y antibacterianos, y al competir con los patógenos por la absorción de nutrientes. Por lo tanto, juegan un papel importante en el crecimiento, la productividad y la calidad de las plantas. Además, el efecto de un fungicida varía según su modo de acción y las especies de HMA asociadas, lo que sugiere que estos hongos tienen un gran potencial como herramienta para la agricultura sostenible ecológica en el actual escenario de calentamiento global.

Arbuscular Mycorrhizal Fungi (AMF) are obligate biotrophs living in symbiotic association with roots of plants. They are among the most widespread soil microorganisms that provide the host plant with nutrients and pathogen protection. Modern farming practices like frequent tillage, high input inorganic fertilization and pesticide along changing climatic conditions due to global warming, have huge impacts on AMF colonization, interaction with plants and on crop productivity. AMF positively affect the plant tolerance to biotic and abiotic stresses, harsh ecosystems and plant pathogens by altering root structure, exudation, rhizosphere microflora, production of antifungals, antibacterials, and competing with pathogens for nutrient uptake. Thus, it plays a significant role in plant growth, productivity and quality. Further, the effect of a fungicide is varied depending on its mode of action and the associated AMF species, suggesting that these fungi have a strong potential as a tool for eco-friendly sustainable farming in the present scenario of global warming.

Effects of different inoculation periods on seedling growth and steroidal saponin content of Paris polyphylla var. yunnanensis / 中草药

Objective: To study the effects of different inoculation periods on seedling growth and steroidal saponin content of Paris polyphylla var. yunnanensis, in order to lay a foundation for cultivating and domesticating high-quality Paris polyphylla var. yunnanensis. Methods: The content of steroidal saponins I, II, VI, and VII in the different vaccination periods of Paris polyphylla var. yunnanensis was determined by HPLC. Meanwhile, trypan blue, UV spectrophotometry and so on were adopted to explore colonization rate, colonization intensity, physiological and biochemical indexes, rhizome biomass of the roots of Paris polyphylla var. yunnanensis. Results: Infection rate of AM fungi was higher in different inoculation periods, activities of protective enzymes, photosynthetic pigments and soluble sugars were increased, soluble protein was not changed, content of MDA was decreased, stress resistance of the seedlings of Paris polyphylla var. yunnanensis was improved, and the growth and development were good. Quality of the cultivar one-year seedlings (recovered in August 2015, T7) was relatively low, and cultivar one-year seedlings (harvested in June or July 2015, T5 and T6) and cultivar two years seedlings (recovered in August 2015, T8) were the best. S2, S3 and S6 treatment groups had better effect in different AM fungi mixed groups. Conclusion: Seedling growth and steroidal saponin content of Paris polyphylla var. yunnanensis inoculated by different inoculation periods had certain effects.

Screening of preponderant arbuscular mycorrhizal fungi species from Paris polyphylla var. yunnanensis seedlings based on biomass and active components / 中草药

Objective To screen preponderant arbuscular mycorrhizal (AM) fungi species from Paris polyphylla var. yunnanensis seedlings based on mycorrhiza viability, rhizome biomass, and active components. Methods After 28 exogenous species of AM fungi were inoculated in sterilized soil, the effects of the mycorrhiza viability of seedling, the biomass in rhizome, the total amount of polyphyllins in single whole seedling, the amount of polyphyllins in rhizome, and the amount of nucleosides in rhizome of P. polyphylla var. yunnanensis were observed by inoculation test in pot at room temperature. Results All the 28 AM groups formed well mycorrhizal structure, the mycorrhiza viability of P. polyphylla var. yunnanensis seedling was enhanced, but it showed preference. Most of the AM treatment groups could improve the biomass in rhizome, the contents and yields of polyphyllins increased, which implied that the accumulation of polyphyllins and nucleosides in P. polyphylla var. yunnanensis seedling were enhanced after inoculation. AM also changed polyphyllins and nucleosides allocation in different organs of P. polyphylla var. yunnanensis seedling in the secondary metablism, the total amount of four kinds of polyphyllins in rootlet were higher than those in rhizome, but the total amount of nine kinds of nucleosides in rhizome were higher than rootlet. Conclusion The performance of different AM strains in this study is of great reference for further improving the biological quantity and quality of the screening of preponderant AM fungi species from P. polyphylla var. yunnanensis seedlings. Gigaspora gigantean, Scutellospora calospora, Diversispora spurca, Dentiscutata heterogama, Septoglomus deserticola, and Ambispora leptoticha can use as the preponderant AM fungi species for the cultivation of mycorrhizal seedlings of P. polyphylla var. yunnanensis.

Role of Arbuscular Mycorrhizae (AM) Fungi and Multi Bioinoculants in Cotton Plant Growth.

Aim: The present study reflects the effect of Arbuscular Mycorrhizae (AM) fungi and other bioinoculants on the growth of cotton seedlings. Study Design: Screening of efficient biofertilizers from undisturbed forest soils to improve the crop yield of cotton in barren lands of Mahabubnagar District. Place and Duration of Study: Department of Microbiology, Palamuru University, Mahabubnagar, Andhra Pradesh, India, between May 2011 and February 2012. Methodology: Mahyco hybrid variety, the most widely cultivated variety in Mahabubnagar District, Andhra Pradesh, India was selected among the sixteen varieties of cotton seeds for this study. Soil samples were analyzed for physicochemical characteristics. Seven different isolates of AM fungi were maintained as pure cultures in laboratory, which were isolated from different Agroforestry tree rhizosphere soils. Among these pure cultures, R1- R2 has shown maximum colonization with Mahyco variety and this isolate was identified as Glomus mosseae. Mahyco hybrid variety was also tested with three different bioinoculants (Rhizobium sp., Azospirillum sp., Bacillus sp.) along with the combination of AM pure culture of R1-R2. These three potential bioinoculants were identified based on 16S rRNA gene sequence. Preliminarily Mahyco hybrid variety was investigated with individual pure cultures of AM fungi and with other bioinoculants. R1-R2 was taken in single, dual, triple and multi combinations with other three bioinoculants. Results: In single combination M+R1-R2 showed the best growth by M+Rhizobium, followed by M+Bacillus and in dual combination M+R1-R2+Rhizobium and in triple combination M+R1-R2+Rhizobium+Azospirillum and in multicombination i.e. M+R1- R2+Rhizobium+Azospirillum+Bacillus showed the best growth among all the combinations. Conclusion: The multicombination mediates increased the cotton growth characteristics. The effect of multicombination was not significantly different in treatment affected by various varieties. Inoculation of multicombination along with AM pure culture resulted significant increase in shoot and root length of cotton plant. So multicombination was proved to be superior.

Differential Growth Response of Various Crop Species to Arbuscular Mycorrhizal Inoculation

To investigate the growth response of various crop species to mycorrhizal inoculation, arbuscular mycorrhizal fungi were applied to Glycine max, Vigna angularis, Senna tora, Hordeum vulgare var. hexastichon. Zea mays, Sorghum bicolor, Allium tuberosum, Solanum melongena, and Capsicum annuum. The biomass of the inoculated crops was measured every two weeks for the 12-week growth period. By measuring biomass, we calculated the mycorrhizal responsiveness of the nine crop species. Among the nine crop species, four species showed a significant response to mycorrhizal inoculation. The shoot biomasses of V. angularis, C. annuum, A. tuberosum, and S. tora significantly increased with mycorrhizal inoculation.

Effects of AM fungi on growth of Bupleurum chinense under different phosphorus levels / 中草药

Objective The effects of AM fungi on the growth of Bupleurum chinense were investigated by inoculation Glomus mosseae, G. caledonium, and the two fungal mixture under different phosphorus levels. Methods Pot culture and experimental analyses were carried out. Results Mycorrhizal infection rate could be promoted by inoculation and increased phosphorus content of plant and root dry weight; the content of chlorophyll, carotenoids, and soluble sugar of leaf was higher than that of controlled plant, and the soluble sugar content of plant root by inoculation the two fungal mixtures were lower than that of controlled plant. The inoculation effect of AM fungi was closed related to AM fungal species and phosphorus applied levels, which was the best under 0.1—0.3 g/kg P_2O_5 soil. Conclusion The growth of host plant and using rate of phosphorus fertilizer can be promoted by inoculation of AM fungi.