Presence of rhizobia in soils in Somalia
4
Citation
6
Reference
10
Related Paper
Citation Trend
Keywords:
Bradyrhizobium japonicum
Bradyrhizobium
Mollisol
Previously, restriction fragment length polymorphism analysis using the nodD1YABC gene probe showed the genetic diversity of common nodD1ABC gene regions of Bradyrhizobium japonicum, Bradyrhizobium elkanii, and the Thai soybean Bradyrhizobium. The nodD1 sequences of representative strains of the 3 groups differed phylogenetically, suggesting that responses of NodD1 proteins of the 3 Bradyrhizobium groups to diverse flavonoids may differ. To confirm this hypothesis, 6 representative strains were chosen from the 3 Bradyrhizobium groups. Six reporter strains were constructed, all carrying the pZB32 plasmid, which contains a nod box and the nodY-lacZ fusion of B. japonicum USDA 110. Differences in nodY-lacZ expression among the strains in response to 37 flavonoid compounds at various concentrations were evaluated. Of those compounds, prunetin (4',5-dihydroxy-7-methoxyisoflavone) and esculetin (6,7-dihydroxycoumarin) were identified as Bradyrhizobium group-specific nod gene inducers. Esculetin showed nod gene induction activities unique to Thai Bradyrhizobium strains. The levels of nodY-lacZ induction among B. japonicum and Thai Bradyrhizobium strains increased with increasing concentration of prunetin, whereas, those in B. elkanii strains did not.
Bradyrhizobium japonicum
Bradyrhizobium
Cite
Citations (12)
Соя (Glycine max (L.) Merr.) является ведущей культурой среди бобовых и ее востребованность в мире ежегодно растает. Для Казахстана соя является стратегической культурой, так как позволяет снизить дефицит белка в питании людей и животных. Однако урожайность сои в Республике по сравнению с другими странами низкая. Из-за низкой урожайности ее производство становится нерентабельным. Для повышения продуктивности сои применяют минеральные азотные удобрения, что создает опасность для окружающей среды. Решением проблемы повышения урожайности сои является применение биоудобрений на основе клубеньковых бактерий, которые фиксируют азот атмосферы и снабжают им растения. Целью данного исследования было выделение нового штамма клубеньковых бактерий с высокой азотфиксирующей активностью, способного увеличивать всхожесть семян, эффективно образовывать клубеньки на корнях сои, стимулировать рост и повышать урожайностьсои. Из клубеньков на корнях растений сои, собранных на полях Алматинской области Казахстана, выделен высокоэффективный штамм бактерий Bradyrhizobium japonicum Н7, способный образовывать большое количество клубеньков, активно фиксировать молекулярный азот атмосферы, улучшать азотное питание растений и повышать урожайность сои. В полевых условиях установлено, что инокуляция штаммом Н7 увеличивает всхожесть семян сои до 90%, повышает густоту посевов на 26–30%, высоту растений - на 25%, а урожайность - на 9-11 ц/га. Таким образом, штамм клубеньковых бактерий Bradyrhizobium japonicum Н7 можно использовать для создания бактериального удобрения для культуры сои. Soybean (Glycine max (L.) Merr.) is the leading crop among legumes and its demand in the world will melt away every year. For Kazakhstan, soybean is a strategic crop, as it allows to reduce the protein deficiency in the nutrition of people and animals. However, soybean productivity in Kazakhstan is low compared to other countries. Due to low yields, its production becomes unprofitable. To increase the productivity of soybeans, mineral nitrogen fertilizers are used, which pose a threat to the environment. The solution to the problem of improving the nitrogen nutrition of soybeans is the use of biofertilizers based on rhizobia, which fix atmospheric nitrogen and supply it to plants. The goal of this study was to isolate a novel strain of rhizobia with high nitrogen-fixing activity, effectively forming nodules on soybean roots, increasing seed germination, promoting growth and increasing soybean productivity. From nodules on the roots of soybean plants collected in the fields of the Almaty region of Kazakhstan, a highly effective strain of rhizobia Bradyrhizobium japonicum H7 was isolated. The strain forms a large number of nodules, actively fixes atmospheric molecular nitrogen, improves nitrogen nutrition of plants and increases soybean yield. Under field conditions, it was found that inoculation with strain H7 increases the germination of soybean seeds up to 90%, seeding density by 26-30%, plant length by 25%, and productivity by 9-11 c/ha. Thus, the rhizobia Bradyrhizobium japonicum H7 can be used to create a bacterial fertilizer for soybean culture.
Bradyrhizobium japonicum
Bradyrhizobium
Biofertilizer
Strain (injury)
Cite
Citations (0)
Soybean rhizobia are Gram negative bacteria that fix nitrogen in root nodules of soybeans. Selection of soybean rhizobia from present and previous soybean cultivation areas is one way to obtain efficient strains for inoculant production. At present, information on the diversity of soybean rhizobia in Thailand is scarce. The experiments aimed to isolate and characterize soybean rhizobium strains in soils from 16 subdistricts in Phitsanulok province, Thailand. Host trapping method was used to isolate bacteria from root nodules of 5 soybean cultivars grown in soils from the 16 subdistricts. Identical RAPD-PCR fingerprints revealed the 202 slow-growing isolates consisted of 121 strains. Authentication tests using 5 soybean cultivars showed all the 121 slow-growing strains had nodulated soybean roots. Four types of colony morphology on yeast extract mannitol containing congo red agar plates were obtained for all the isolated strains. Bromothymol blue (BTB) reactions on BTB agar plates revealed two types of slow-growing soybean rhizobia. Type 1 secreted alkali products after 5-day incubation, and acidic products upon prolonged incubation for another 5 days. Type 2 secreted only alkali products after 5- and 10-day incubation. Results from nucleotide sequences of 16S rDNA revealed 7, 6, and 2 strains of Bradyrhizobium elkanii, B. japonicum, and B. yuanmingense, respectively. The B. elkanii and B. japonicum strains were found to be natural variants with different RAPD-PCR fingerprints. This study is the first report on the findings of B. yuanmingense as well as natural variants of slow-growing soybean rhizobia in Thailand.
Bradyrhizobium japonicum
Bradyrhizobium
Cite
Citations (3)
Bradyrhizobium japonicum
Sinorhizobium
Bradyrhizobium
Plant biochemistry
Sinorhizobium meliloti
Cite
Citations (2)
Bradyrhizobium japonicum
Bradyrhizobium
Nod factor
Cite
Citations (0)
Free-living soybean rhizobia and Bradyrhizobium spp. (lupine) have the ability to catabolize ethanol. Of the 30 strains of rhizobia examined, only the fast- and slow-growing soybean rhizobia and the slow-growing Bradyrhizobium sp. (lupine) were capable of using ethanol as a sole source of carbon and energy for growth. Two strains from each of the other Rhizobium species examined ( R. meliloti, R. loti , and R. leguminosarum biovars phaseoli, trifolii , and viceae ) failed to grow on ethanol. One Rhizobium fredii (fast-growing) strain, USDA 191, and one (slow-growing) Bradyrhizobium japonicum strain, USDA 110, grew in ethanol up to concentrations of 3.0 and 1.0%, respectively. While three of the R. fredii strains examined (USDA 192, USDA 194, and USDA 205) utilized 0.2% acetate, only USDA 192 utilized 0.1% n -propanol. None of the three strains utilized 0.1% methanol, formate, or n -butanol as the sole carbon source.
Bradyrhizobium japonicum
Bradyrhizobium
Strain (injury)
Cite
Citations (11)
The effect of pH on the nodulation of Sinorhizobium fredii and Bradyrhizobium japonicum was examined by analyzing the indigent soybean rhizobia, predominant indigent rhizobia, and specific rhizobia, respectively. The results showed that very acid and very alkaline environment could retard the nodulation and inhibit the growth of the rhizobia. Sinorhizohium fredii could endure environment more strongly than Bradyrhizobium japonicum, and had a high competitive nodulation capacity. Bradyhizobium japonicum could endure acid environment more strongly than Sinorhizobium fredii. In very acid and very alkaline environment, the nodulation capacity of S. fredii and B. japonicum was mainly determined by their physiological characteristics.
Bradyrhizobium japonicum
Bradyrhizobium
Sinorhizobium
Sinorhizobium meliloti
Cite
Citations (3)
Bradyrhizobium japonicum
Bradyrhizobium
Strain (injury)
Cite
Citations (14)
The nodule bacteria were isolated from the nodules of cowpea. On the basis of phenotypical properties these rhizobia were referred to slow growing bacteria of Bradyrhizobium genus. Interaction features of cowpea with the nodule bacteria of cowpea (Bradyrhizobium sp. (Vigna)) and soybean (Bradyrhizobium japonicum) on nitrogen-free substrate and in soil culture were studied. It was established that the cowpea rhizobia strains possess high specificity to the host plant, promote symbiotic nitrogen fixation activity in 1,8-2,6 times and increase plants aboveground mass yield in 1,4-3,4 times, in comparison with control. The significant positive influence of the active soybean microsymbiont Bradyrhizobium japonicum 46 on the growth and development of cowpea was shown.
Bradyrhizobium japonicum
Bradyrhizobium
Symbiotic bacteria
Nodule (geology)
Cite
Citations (0)
This study aimed to determine the molecular identities and genetic relatedness of rhizobia isolated from pigeon pea and pinto beans, and assess their remediation potential in the presence of 1 %, 3 % and 5 % (w/v) crude oil in minimal medium for 7 days incubation period. Standard microbiological and molecular methods which include amplification and purification of 16S rRNA, agarose gel electrophoresis, and sequencing. Results showed molecular identities of six rhizobia from pigeon peas as Bradyrhizobium diazoefficiens USDA122, Rhizobium leguminosarum WSM2304, Bradyrhizobium japonicum N61, Rhizobium leguminosarum N741, Rhizobium leguminosarum BIHIB1217, and Bradyrhizobium japonicum E109; and three rhizobia obtained from pinto beans were Rhizobium leguminosarum N871, Bradyrhizobium diazoefficiens USDA110 and Bradyrhizobium japonicum SEMIA5079. All tested rhizobia (9) showed petroleum degradation ability, as they all grew in the 1, 3 and 5 % (w/v) crude oil minimal medium under laboratory conditions. B. diazoefficiens USDA122 showed the highest optical density (OD) value of 1.184 ± 0.05 on 7th day at 1 % (w/v) crude oil contamination, while R. leguminosarum N741 has the lowest OD value of 0.372 ± 0.02 at 5 % (w/v) crude oil on 7th day. For all the rhizobia, increase occurred throughout incubation period at 1, 3 and 5 % (w/v) except Rhizobium leguminosarum N741 and R. leguminosarum BIHIB1217. In conclusion, the association of R. leguminosarum BIHIB1217 and R. leguminosarum N871 from pigeon pea and pinto beans respectively, were found most effective in crude oil degradation and thus they are recommended as a promising association for remediation of crude oil spilled soils.
Rhizobium leguminosarum
Bradyrhizobium japonicum
Bradyrhizobium
Cite
Citations (3)