Bacillus spp. as plant growth-promoting bacteria in cotton under greenhouse conditions

Abstract

The use of plant growth-promoting bacteria (PGPB) is a promising alternative method to improve plant efficiency in the utilization of chemical fertilizers, enabling a reduction of fertilizer application on crops. This study aimed to evaluate the potential of ten Bacillus strains (eight B. subtilis, one B. velezensis and one B. amyloliquefaciens) to promote growth in cotton plants under greenhouse conditions. The experiment was performed in a completely randomized design with 11 treatments and five replicates under greenhouse conditions. The parameters related to plant growth from treatments that received the bacterial isolates were compared to the control. The parameters analyzed were shoot dry matter, root dry matter, total dry matter, plant height, nitrogen content and phosphorus content in soil and in plants. The highest root dry matter was 1.24 g for the isolate 263. The total dry matter was 4.0 g for the isolate 248 and 3.54 g for the isolate 290. The highest chlorophyll content was 28 µg/cm2 for the isolate 290. The higher N content in shoot dry matter was 28 g of N for the isolate 290, 26 g for the isolate 248 and 25 g for the isolate 320. The improved P efficiency use was 32% for the isolate 248, 28% for the isolate 188 and 27% for the isolate 274. These results strongly confirm that B. subtilis isolates 248, 290 and 263 may represent a good alternative as plant growth-promoting endophytes to cotton crops, as they positively affected several parameters evaluated, such as root and shoot dry matter and phosphorus content in the soil. In addition, the parameters evaluated can strongly and positively affect plant yield. However, some isolates of B. subtilis did not promote plant growth and most likely failed as bioinoculants. This result shows the importance of properly identifying the isolate for bioinoculation to achieve success in promoting plant growth.

Potential of Biostimulants Based on PGPR Rhizobacteria Native to Benin’s Soils on the Growth and Yield of Maize (<i>Zea mays </i> L.) under Greenhouse Conditions

“…This is due to the particular conditions of use of each microbial group [7]. The application of biostimulants makes it possible to reduce the use of chemicals that have generated a serious environmental impact [8] [9].…”

Effect of Aspergillus and Bacillus Concentration on Cotton Growth Promotion

“…Microorganisms (bacteria and fungi) used in this study belong to the collection of the Laboratory of Soil Microbiology, UNESP, Campus of Jaboticabal (Table 1) and were selected for presenting growth-promoting characteristics such as phosphorus solubilization, biological nitrogen fixation, and indole acetic acid production (Baron et al, 2018;Diaz et al, 2019;Milani et al, 2019). The microorganisms used in the study were pre-inoculated in Petri dishes containing nutrient agar for bacteria and potato dextrose agar for fungi.…”

Aspergillus spp. and Bacillus spp. as Growth Promoters in Cotton Plants Under Greenhouse Conditions

“…Another nutrient that plays an important role in plants is phosphorus, which forms biological molecules; however, its low availability and high fixation in the soil are problems that lead to deficiencies; thus, phosphorus is a limiting factor for plant growth (Anand et al, 2016). In view of the above, the nutritional requirements for cotton production can be addressed by using plant growth-promoting microorganisms (Diaz et al, 2019).…”

“…Studies have shown that the use of plant growth-promoting microorganisms as inoculants is a viable strategy in current agricultural production systems (Romero-Perdomo et al, 2017;Numan et al, 2018;Diaz et al, 2019); therefore, the search for new microorganisms must be constant to face current and future problems in cotton crops.…”