Growth and Competitive Infection Behaviors of Bradyrhizobium japonicum and Bradyrhizobium elkanii at Different Temperatures

Abstract

Growth and competitive infection behaviors of two sets of Bradyrhizobium spp. strains were examined at different temperatures to explain strain-specific soybean nodulation under local climate conditions. Each set consisted of three strains—B. japonicum Hh 16-9 (Bj11-1), B. japonicum Hh 16-25 (Bj11-2), and B. elkanii Hk 16-7 (BeL7); and B. japonicum Kh 16-43 (Bj10J-2), B. japonicum Kh 16-64 (Bj10J-4), and B. elkanii Kh 16-7 (BeL7)—which were isolated from the soybean nodules cultivated in Fukagawa and Miyazaki soils, respectively. The growth of each strain was evaluated in YM liquid medium at 15, 20, 25, 30, and 35 °C with shaking at 125 rpm for one week while measuring their OD660 daily. In the competitive infection experiment, each set of the strains was inoculated in sterilized vermiculite followed by sowing surface-sterilized soybean seeds, and they were cultivated at 20/18 °C and 30/28 °C in a 16/8 h (day/night) cycle in a phytotron for three weeks, then nodule compositions were determined based on the partial 16S-23R rRNA internal transcribes spacer (ITS) gene sequence of the isolates from the nodules. The optimum growth temperatures were at 15–20 °C for all B. japonicum strains, while they were at 25–35 °C for all B. elkanii strains. In the competitive experiment with the Fukagawa strains, Bj11-1 and BeL7 dominated in the nodules at the low and high temperatures, respectively. In the Miyazaki strains, BjS10J-2 and BeL7 dominated at the low and high temperatures, respectively. It can be assumed that temperature of soil affects rhizobia growth in rhizospheres and could be a reason for the different competitive properties of B. japonicum and B. elkanii strains at different temperatures. In addition, competitive infection was suggested between the B. japonicum strains.

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

“…B. megaterium strains have the ability to grow at a temperature range 3–45 °C [ 34 ], whereas Br. japonicum strains tolerate 15–20 °C and below well, although less frequently [ 35 ]. However, bacterial growth and activity were obviously not influenced by suboptimal conditions in the current study.…”

In vitro interactions between Bradyrhizobium spp. and Tuber magnatum mycelium

“…Bradyrhizobium strain isolation and purification were made by streak‐planting (Sanders, 2012) on YMA at 28°C in the dark, which are the best conditions for Bradyrhizobium growth (Hafiz et al, 2021; Vincent, 1970). The isolation was carried out starting from the bacterial population of each fungal strain.…”

Horticultural Crop Response to Different Environmental and Nutritional Stress

“…The effect of environment conditions (temperature, rainfall, altitude, soil types, hail) [5][6][7][8][9], nutritional strategies [5,6,[10][11][12][13][14], water (stress, salinity) [5,8,12,15], container substrate of cultivation [16] on yield, yield traits and quality were analyzed in different crops in an open field [8,9,13,14,17] and greenhouses [5][6][7][10][11][12]15,16].…”

“…Different innovative strategies were presented that included protected structures, container type, cultivation techniques [5,10,16], symbiotic relationships [6,7], fertigation strategies [10] new agricultural management technologies (remote sensing, smartphone) [11] novel hybrids for breeding [12] spraying of Gibberellic acid [17], water supplies [8,15] and substrate [16] cover crops management [13] and stand reduction [9].…”

“…Growth and competitive infection behaviors of two sets of Bradyrhizobium spp. strains were examined at different temperatures to explain strain-specific soybean nodulation under local climate conditions [6]. Each set consist of three strains-B.…”