Seed Treatments with Microorganisms Can Have a Biostimulant Effect by Influencing Germination and Seedling Growth of Crops

Abstract

Seed quality is an important aspect of the modern cultivation strategies since uniform germination and high seedling vigor contribute to successful establishment and crop performance. To enhance germination, beneficial microbes belonging to arbuscular mycorrhizal fungi, Trichoderma spp., rhizobia and other bacteria can be applied to seeds before sowing via coating or priming treatments. Their presence establishes early relationships with plants, leading to biostimulant effects such as plant-growth enhancement, increased nutrient uptake, and improved plant resilience to abiotic stress. This review aims to highlight the most significant results obtained for wheat, maize, rice, soybean, canola, sunflower, tomato, and other horticultural species. Beneficial microorganism treatments increased plant germination, seedling vigor, and biomass, as well as overcoming seed-related limitations (such as abiotic stress), both during and after emergence. The results are generally positive, but variable, so more scientific information needs to be acquired for different crops and cultivation techniques, with considerations to different beneficial microbes (species and strains) and under variable climate conditions to understand the effects of seed treatments.

Bio-Priming of Soybean with Bradyrhizobium japonicum and Bacillus megaterium: Strategy to Improve Seed Germination and the Initial Seedling Growth

“…japonicum and Bacillus strains, which were shown to have PGP activity, increased nodule number, total biomass, total nitrogen, and yield, under the conditions of low root zone temperatures [ 37 ]. Cardarelli et al [ 8 ] reported that the application of beneficial microorganisms to the seeds of the major crops resulted in increased germination, seedling vigor, biomass, and the ability to overcome stress both during and after emergence. Generally, seed bio-priming with PGPR improves seed quality, plant growth and stress tolerance through production of regulatory substances, nutrient enhancement, and plant protection [ 38 ].…”

“…Problems in soybean seed quality occur during pre- and postharvest periods, and mostly include seed deterioration due to adverse environmental conditions, and seed diseases due to numerous pathogens [ 7 ]. In order to improve soybean seed quality, especially under stressful conditions and/or diseases, numerous researchers have explored different strategies, including pre-sowing seed treatments with beneficial microorganisms [ 8 ]. The development of microbial inoculants using plant growth-promoting rhizobacteria (PGPR) is increasingly regarded as an environmentally-friendly alternative to the extensive use of synthetic chemicals in agriculture [ 9 ].…”

Thinking for the future: Phytoextraction of cadmium using primed plants for sustainable soil clean‐up

“…Microorganisms can be used in seed biopriming, using cyanobacteria ( Spirulina platensis ) can enhance maize's tolerance to cadmium via accelerated germination, restriction of Cd translocation, and improvement of photosynthetic electron flows and non‐photochemical quenching (Seifikalhor et al, 2020). The use of microorganisms in seed priming processes can effectively enhance plant performance by influencing germination rates and seedling growth (Cardarelli et al, 2022), thus enabling plants to cope better with heavy metal stress‐induced injuries (Figure 3).…”

Effects of Rhizobium leguminosarum Thy2 on the Growth and Tolerance to Cadmium Stress of Wheat Plants

“…Increasing agricultural crop productivity, especially cereals such as wheat, is relevant and extremely important [ 1 , 2 , 3 , 4 ]. One of the guiding principles of modern agricultural production is the introduction of environmentally sound and harmless approaches that are safe for human health [ 1 , 5 , 6 , 7 ].…”