Root and shoot development of corn seedlings as affected by rhizobacteria

Abstract

Multifunctional microorganisms are beneficial microorganisms able of promoting plant growth through direct and indirect mechanisms. Because of this, has enormous potential for use when aiming a sustainable agriculture. The objective of this work was to determine the effect of seed inoculation with multifunctional microorganisms on the initial development of corn seedlings. The experiment was carried out under controlled conditions in a completely randomized design, with seven treatments and six replications. Treatments consisted of microbiolization of corn seeds with the rhizobacteria: 1. Burkholderia cepacea (BRM 32111), 2. Serratia marcenses (BRM 32113), 3. Serratia sp. (BRM 32114), 4. Bacillus sp. (BRM 63573), 5. Azospirillum brasilense (Ab-V5), 6. Azospirillum sp. (BRM 63574) and 7. control treatment (no microorganisms). For each experimental unit, 500 mL plastic pots filled with soil and two corn seeds were used. After 14 days the seedlings were removed from the pots, set aside from the ground and photographed with a digital camera. The images presented were analyzed by WinRHIZO 2012 software to determine: total root length, root diameter, total root surface area and root volume. After this, roots and shoots of the seedlings were dried and weighed. Corn seedlings treated with the multifunctional microorganisms Bacillus sp. (BRM 63573), Serratia sp. (BRM32114) and Azospirillum sp. (BRM 63574) presented increased in the root and shoots biomass compared to untreated seeds. The microorganism Azospirillum sp. (BRM 63574) was the one that provided the highest values in the parameters of total root length, root diameter, root volume, root dry mass, shoot dry mass and total dry mass compared to the control treatment. The use of multifunctional microorganisms is a promising alternative to provide greater development of corn seedlings.

Interação de plântulas de soja com rizobactérias benéficas

“…Figure 2 displays images of the root system of soybean seedlings treated with the beneficial rhizobacteria evaluated in this study. Similar results were obtained for the root system of rice and corn treated with Azospirillum sp., showing an increase of 86.3% and 43.7%, respectively (Fernandes et al, 2021;Cruz et al, 2022) Serratia marcescens (BRM 32114), and Bacillus spp. (BRM63573) showed a significant increase in total dry matter (MST) of 36.6%, 35.9%, and 32.4%, respectively, and in aboveground dry matter (MSPA) by 39.0%, 43.8%, and 41.0%, respectively, compared to the control treatment (Table 2).…”

“…They contribute to biological nitrogen fixation (Pacentchuck et al, 2020), inorganic phosphate solubilization, and organic phosphate mineralization, as well as inhibition of ethylene production (Santoyo et al, 2016), and mitigation of oxidative, saline, and water stresses. Recent studies have demonstrated the beneficial effects of multifunctional microorganisms in crops such as rice (Fernandes et al, 2021), maize (Cruz et al, 2022), common beans (Rezende et al, 2021), soybeans (Chagas et al, 2022), among others. For soybean seed microbiolization, the seeds were immersed in bacterial suspensions (Filippi et al, 2011) produced by cultivating the mentioned rhizobacteria on solid medium (nutrient agar).…”

“…+ Azospirillum spp., suggesting that root system colonization by microorganisms led to increased root development, resulting in greater water and nutrient absorption by the plants. Cruz et al (2022) described an increase in the aboveground dry matter of corn seedlings treated with Azospirillum sp. (83.13%) and Bacillus sp.…”

“…These results may be related to the ability of microorganisms to produce phytohormones and solubilize nutrients. Additionally, seedlings with higher dry matter accumulation signal greater nutrient absorption, directly affecting growth, stress tolerance, and increased productivity potential (Cruz et al, 2022).…”

Desenvolvimento inicial de arroz de terras altas inoculado e coinoculado com rizobactérias multifuncionais

“…P. da Silva & Dourado, 2022a). These mechanisms mainly benefit the greater root development, providing conditions for the plant to explore a larger volume of soil and absorb more water and nutrients (Cruz et al, 2022).…”