Examinando por Materia "Plant growth-promoting rhizobacteria"

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Biocontrol and plant growth-promoting potential of Bacillus and actinomycetes isolated from the rhizosphere and phyllosphere of potato (Solanum tuberosum L.) from different agroecological zones of Peru
(MDPI, 2025-12-23) Mamani Rojas, Lizbeth Margarita; Rengifo Sánchez, Raihil Rabindranath; Velarde Apaza, Leslie Diana; Ramírez Rojas, Max; Cántaro Segura, Hector
Potato (Solanum tuberosum L.) is a key staple crop in the Peruvian Andes, but its productivity is threatened by fungal pathogens such as Rhizoctonia solani and Alternaria alternata. In this study, 71 native bacterial strains (39 from phyllosphere and 32 from rhizosphere) were isolated from potato plants across five agroecological zones of Peru and characterized for their plant growth-promoting (PGPR) and antagonistic traits. Actinomycetes demonstrated broader enzymatic profiles, with 2ACPP4 and 2ACPP8 showing high proteolytic (68.4%, 63.4%), lipolytic (59.5%, 60.6%), chitinolytic (32.7%, 35.5%) and amylolytic activity (76.3%, 71.5%). Strain 5ACPP5 (Streptomyces decoyicus) produced 42.8% chitinase and solubilized both dicalcium (120.6%) and tricalcium phosphate (122.3%). The highest IAA production was recorded in Bacillus strain 2BPP8 (95.4 µg/mL), while 5ACPP6 was the highest among Actinomycetes (83.4 µg/mL). Siderophore production was highest in 5ACPP5 (412.4%) and 2ACPP4 (406.8%). In vitro antagonism assays showed that 5ACPP5 inhibited R. solani and A. alternata by 86.4% and 68.9%, respectively, while Bacillus strain BPP4 reached 51.0% inhibition against A. alternata. In greenhouse trials, strain 4BPP8 significantly increased fresh tuber weight (11.91 g), while 5ACPP5 enhanced root biomass and reduced stem canker severity. Molecular identification confirmed BPP4 as Bacillus halotolerans and 5ACPP5 as Streptomyces decoyicus. These strains represent promising candidates for the development of bioinoculants for sustainable potato cultivation in Andean systems.
The effects of the inoculation of bacterial microorganisms (Pseudomonas sp. and Bacillus sp.) on soil quality, aerial biomass and nutritional quality of native grasses under field conditions in the Peruvian highlands
(Soil Science Society of Poland, 2026-04-15) Arias Arredondo, Alberto Gilmer; Pizarro Carcausto, Samuel Edwin; Requena Rojas, Edilson Jimmy; Verástegui Martínez, Patricia; Cruz Luis, Juancarlos Alejandro; Solórzano Acosta, Richard Andi
Peruvian highland ecosystems cover approximately 22 million hectares and provide key ecosystem services that support human well-being and food security. Soil functioning in these ecosystems largely depends on the activity of microbial communities. This study evaluated the effects of Pseudomonas sp. and Bacillus sp. inoculation on soil chemical properties, aerial biomass production, and nutritional quality of Festuca dolichophylla, Jarava ichu and Cinnagrostis vicunarum. A field experiment was conducted at 4379 m a.s.l. in the central Peruvian highlands. Bacterial inoculation increased soil organic matter and nitrogen availability in plots dominated by J. ichu and F. dolichophylla inoculated with Bacillus sp., compared to non-inoculated controls. Higher soil phosphorus content was observed in C. vicunarum pastures inoculated with Pseudomonas sp. In terms of biomass production, significant increases were recorded in C. vicunarum under both bacterial inoculations and in F. dolichophylla associated with Bacillus sp., while J. ichu showed higher yields with Pseudomonas sp. In addition, bacterial inoculation improved forage nutritional quality, particularly total protein, calcium, and phosphorus contents in J. ichu, highlighting species-specific plant–microorganism interactions. Overall, the inoculation of beneficial bacteria represents a promising and environmentally sustainable strategy to improve soil quality, forage productivity, and nutritional value in native highland grasslands, contributing to more resilient rangeland systems and the conservation of ecosystem services.