Plant-Growth-Promoting Rhizobacteria Improve Seeds Germination and Growth of Argania spinosa

• Published in: Plants (Basel) 2024-08, Vol.13 (15), p.2025
• Main Authors: Chabbi, Naima, Chafiki, Salahddine, Telmoudi, Maryem, Labbassi, Said, Bouharroud, Rachid, Tahiri, Abdelghani, Mentag, Rachid, El Amri, Majda, Bendiab, Khadija, Hsissou, Driss, Mimouni, Abdelaziz, Ait Aabd, Naima, Qessaoui, Redouan
• Format: Article
• Language: English
• Subjects: Acetic acid; Acid production; Agricultural ecosystems; Agricultural production; Agriculture; Alcaligenes; Algae; Argania spinosa; Availability; Bacteria; Biodegradation; Biodiversity; biofertilization; Brevundimonas; Climate change; Collars; Community involvement; Corn; Crop growth; Degradation; DNA sequencing; Enrichment; Environmental protection; Farm buildings; Fertilization; Gene sequencing; Germination; Greenhouses; In vitro methods and tests; Indoleacetic acid; Microorganisms; Mycorrhizas; Nitrogen; Nutrient availability; Nutrients; PGPR; Phosphorus; Physiology; Plant diseases; Plant extracts; Plant growth; Reforestation; Rhizosphere; Root development; seedling; Seeds; Socioeconomic factors; Soil degradation; Soil improvement; Soil nutrients; Soil quality; Solubilization; Sustainability management; Sustainable agriculture; Sustainable development; Sustainable practices; Taxonomy; Trees; VOCs; Volatile organic compounds
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants13152025

is among the most important species of the Moroccan forest in terms of ecological, environmental, and socio-economic aspects. However, it faces a delicate balance between regeneration and degradation in its natural habitat. Hence, the efforts to preserve and regenerate argan forests are crucial for biodiversity, soil quality, and local livelihoods, yet they face challenges like overgrazing and climate change. Sustainable management practices, including reforestation and community engagement, are vital for mitigating degradation. Similarly, exploiting the argan tree's rhizosphere can enhance soil quality by leveraging its rich microbial diversity. This approach not only improves crop growth but also maintains ecosystem balance, ultimately benefiting both agriculture and the environment. This enrichment can be achieved by different factors: mycorrhizae, plant extracts, algae extracts, and plant growth-promoting rhizobacteria (PGPR). The benefits provided by PGPR may include increased nutrient availability, phytohormone production, shoot, root development, protection against several plant pathogens, and disease reduction. In this study, the effect of rhizobacteria isolated from the Agran rhizosphere was evaluated on germination percentage and radicle length for in vitro tests, growth, collar diameter, and branching number under greenhouse conditions. One hundred and twenty (120) bacteria were isolated from the argan rhizosphere and evaluated for their capacity for phosphate solubilization and indole acetic acid production. The results showed that 52 isolates could solubilize phosphorus, with the diameters of the solubilization halos varying from 0.56 ± 0.14 to 2.9 ± 0.08 cm. Among 52 isolates, 25 were found to be positive for indole acetic acid production. These 25 isolates were first tested on maize growth to select the most performant ones. The results showed that 14 isolates from 25 tested stimulated maize growth significantly, and 3 of them by 28% (CN005, CN006, and CN009) compared to the control. Eight isolates (CN005, CN006, CN004, CN007, CN008, CN009, CN010, and CN011) that showed plant growth of more than 19% were selected to evaluate their effect on argan germination rate and radicle length and were subjected to DNA extraction and conventional Sanger sequencing. The 8 selected isolates were identified as: sp2, , sp3, sp4, sp1, sp2, sp1, and . The results showed that sp2 significantly increased the germination rate by 95.83%, and the radicle length wi