Enhanced attachment of Bradyrhizobium japonicum to soybean through reduced root colonization of internally seedborne microorganisms

2000 ◽  
Vol 46 (7) ◽  
pp. 600-606 ◽  
Author(s):  
Nathan W Oehrle ◽  
Dale B Karr ◽  
Robert J Kremer ◽  
David W Emerich

Internally seedborne microorganisms are those surviving common surface sterilization procedures. Such microbes often colonize the radicle surface of a germinating soybean (Glycine max) seed, introducing an undefined parameter into studies on attachment and infection by Bradyrhizobium japonicum. Bacterial isolates from surface-sterilized soybean seed, cv. Williams 82 and cv. Maverick, used in our studies, were identified as Agrobacterium radiobacter, Aeromonas sp., Bacillus spp., Chryseomonas luteola, Flavimonas oryzihabitans, and Sphingomonas paucimobilis. Growth of these microbes during seed germination was reduced by treating germinating seeds with 500 µg/mL penicillin G. The effects of this antibiotic on seedling development and on B. japonicum 2143 attachment, nodulation, and nitrogen fixation are reported here. Penicillin G treatment of seeds did not reduce seed germination or root tip growth, or affect seedling development. No differences in nodulation kinetics, nitrogen fixation onset or rates were observed. However, the number of B. japonicum attached to treated intact seedlings was enhanced 200-325%, demonstrating that other root-colonizing bacteria can interfere with rhizobial attachment. Penicillin G treatment of soybean seedlings can be used to reduce the root colonizing microbes, which introduce an undefined parameter into studies of attachment of B. japonicum to the soybean root, without affecting plant development.Key words: internally seedborne microorganisms, penicillin G, Bradyrhizobium japonicum, microbial attachment, soybean (Glycine max).

1994 ◽  
Vol 40 (6) ◽  
pp. 456-460 ◽  
Author(s):  
M. L. Ferrey ◽  
P. H. Graham ◽  
M. P. Russelle

Competition from existing soil rhizobia has limited the benefits from nitrogen fixation for soybean grown in the American Midwest. A strategy being considered to overcome this problem is the use of varieties that are restricted in nodulation with soil strains, but nodulate normally with inoculant bradyrhizobia. In this study we examine the efficiency in nodulation of strains of Bradyrhizobium japonicum that have been reported as restricted in nodulation with specific genotypes of soybean, using a root-tip marking procedure in growth pouches. When B. japonicum USDA110 was applied to the soybean cultivars Hardee and Fiskeby V at the rate of 3.50 × 104 cells/pouch, more than 75% of the plants were nodulated above the root-tip mark, and average uppermost nodule position was above the root-tip mark. By contrast, when this strain was applied in similar concentration to the soybean cultivar Peking, few plants developed nodules above the root-tip mark, and the average position of the uppermost taproot nodule was nearly 30 mm below this mark. Nodulation was improved at higher rates of inoculation, but even when 3.50 × 106 cells were applied to each pouch, less than 50% of the plants were nodulated above the root-tip mark. Bradyrhizobium japonicum strain CB1809 (=USDA136) was also efficient in nodulation with cv. Fiskeby V, but with cv. Hardee, less than 65% of plants were nodulated above the root-tip mark, irrespective of inoculation rate. Because restriction of nodulation with the strains initially tested was not absolute, we examined the patterns of nodulation obtained following the inoculation of two restriction hosts, Peking and PI371607. In pure culture, serogroup USDA110 strains failed to induce significant taproot nodulation of cv. Peking in Leonard jars, but did induce lateral root nodulation. However, in a glasshouse experiment contrasting soil- and seed-applied inoculant, lateral-root nodulation of the restriction host PI371607 by USDA123 was not significant.Key words: Glycine max, competition, restriction, nodulation.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1473
Author(s):  
Zlatica Mamlic ◽  
Ivana Maksimovic ◽  
Petar Canak ◽  
Goran Mamlic ◽  
Vojin Djukic ◽  
...  

Soybean production in the system of organic agriculture is not very demanding, and this has been well documented both through experimental results and commercial production. However, one of the biggest problems in organic production is the lack of adequate pre-sowing treatments. Therefore, the aim of this study was to examine the effect of the electrostatic field. This is a physical treatment that was first used for seed treatment in the 18th century but has mostly been neglected since then. Seeds of five soybean genotypes with differently colored seed coats (yellow, green, dark green, brown, and black) were included in this study. The seeds were exposed to different values of direct current (DC) with the following voltages: 0 V (control), 3 V, 6 V, and 9 V, to which the seeds were exposed for 0 min (control), 1 min, and 3 min. After exposing the seeds to the electric field, the physiological properties of seeds and seedlings at the first stage of growth were evaluated. The results show that the effect of the electrostatic field on seed quality depends on the genotype, voltage, and exposure time. The application of DC can be a suitable method for improving seed germination and the initial growth of soybean seedlings. In addition, the results indicate that it is necessary to adjust the DC treatment (voltage and duration of exposure of seeds) to particular genotypes since inadequate treatments may reduce the quality of seeds.


Weed Science ◽  
1981 ◽  
Vol 29 (4) ◽  
pp. 433-439 ◽  
Author(s):  
Robert E. Hoagland ◽  
Stephen O. Duke

Effects of 16 herbicides representing 14 herbicide classes on growth and extractable phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) were examined in light- and dark-grown soybean [Glycine max(L.) Merr. ‘Hill’] seedlings. High purity (96 to 100%) herbicides were supplied via aqueous culture at various concentrations: 0.5 mM amitrole (3-amino-s-triazole), 0.1 mM atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], 0.07 mM diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoicacid}, 0.5 mM DSMA (disodium methanearsonate), 0.2 mM fenuron (1,1-dimethyl-3-phenylurea), 0.05 mM fluridone {1-methyl-3-phenyl-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone}, 0.5 mM MH (1,2-dihydro-3,6-pyridazinedione), 0.5 mM metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], 1.8 μM nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], 0.5 mM norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], 0.05 mM paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), 0.15 mM perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide}, 0.2 mM propanil (3′,4′-dichloropropionanilide), 0.1 mM propham (isopropyl carbanilate), 0.5 mM TCA (trichloroacetic acid), and 0.05 mM 2,4-D [(2,4-dichlorophenoxy)acetic acid]. Dark-grown soybean seedlings (3-day-old) were transferred to control solutions (2 mM CaSO4) or to herbicide solutions (in 2 mM CaSO4) and grown at 25 C in continuous white light (200 μE•m-2•s-1) or continuous darkness until harvested 24 or 48 h after transfer. After 48 h, growth (fresh weight, dry weight, elongation) was inhibited by most of the chemicals. Other signs of toxicity (necrosis, secondary root stunting, and root tip swelling) were noted for some treatments. Roots were most affected, although hypocotyls were generally not changed. Hypocotyl elongation was stimulated by atrazine, fluridone, and norflurazon after 48 h light. Extractable PAL activity from soybean axes was decreased by atrazine, fenuron, metribuzin, norflurazon, propanil, propham, and 2,4-D. Amitrole and paraquat were the only herbicides that increased extractable PAL activity. Other compounds tested had no effect on the enzyme. None of the herbicides significantly affected in vitro PAL activity.


2020 ◽  
Vol 2 (5) ◽  
Author(s):  
Gabriel Sgarbiero Montanha ◽  
Eduardo Santos Rodrigues ◽  
João Paulo Rodrigues Marques ◽  
Eduardo de Almeida ◽  
Marina Colzato ◽  
...  

2018 ◽  
Vol 67 (2) ◽  
pp. 297-302 ◽  
Author(s):  
Alessandro Pedrozo ◽  
Nelson João Girelli de Oliveira ◽  
Odair Alberton

La soya es uno de los cultivos más importantes del mundo y presenta una gran versatilidad. Este estudio tiene como objetivo investigar el efecto del inoculante Bradyrhizobium japonicum a 0, 600 y 1200 ml ha-1 en cultivo de soya, con y sin 1 L ha-1 calcio (Ca 41%) + 0,4 L ha-1 boro (B 14 %). Las plantas se cultivaron durante 90 días en macetas de plástico con 3 kg de arena y vermiculita (v / v) tratadas en autoclave a 121°C durante 1 h. El experimento se realizó en un diseño completamente aleatorizado con cinco repeticiones en un invernadero. Se evaluaron los parámetros de rendimiento de soja, tales como, peso seco del brote, raíz y total; altura de la planta, nitrógeno en el brote; número y peso seco de los nódulos; índice de clorofila en las hojas; cantidad de mazorcas por planta (NPPL); número de granos por pod (NGP); y número de granos por planta (NGPL). La adición de Ca + B aumentó significativamente NPPL, NGPL y NGP. El NPPL y NGPL se incrementaron significativamente con 600 mL ha-1 del inoculante. La dosis de 600 ml ha-1 del inoculante combinado con Ca + B estimuló significativamente NPPL, NGPL y NGP. Se concluye que la productividad de la soya se incrementó con la adición de 600 mL ha-1 de inoculante, en combinación con Ca y B.


2020 ◽  
Vol 27 ◽  
pp. 119-124
Author(s):  
S. Ya. Kots ◽  
T. P. Mamenko ◽  
R. A. Yakymchuk

Aim. To investigate the use of soybean seed inoculation by nodule bacteria obtained by transposon mutagenesis to ensure the effective formation and functioning of symbiotic systems by regulating prooxidant - antioxidant processes and reducing the negative effects of drought on crop productivity. Methods. Microbiological, physiological, biochemical methods, gas chromatography and spectrophotometry. Results. It has been proved that due to the activation of protective antioxidant enzymes of catalase, ascorbate and guaiacol peroxidase in soybean roots and root nodules, adaptive rearrangements of plant metabolism occur aimed at stabilizing the content of prooxidants, hydrogen peroxide, in drought conditions. At the same time, the specific nitrogen-fixation activity of soybean root nodules undergoes no significant changes and indicates the preservation of the effective functioning of the symbiotic apparatus, is the result of activation of protective antioxidant processes and adaptation of the soybean symbiotic system with the participation of Tn-5 mutant Bradyrhizobium japonicum B1-20 to dehydration conditions. Conclusions. The use of inoculation of soybean seeds with the Tn-5 mutant Bradyrhizobium japonicum B1-20 leads to regulation of prooxidant - antioxidant protective processes in plants, helps to increase their nitrogen-fixation potential and maintain grain yield under prolonged exposure to drought. Keywords: soybean (Glycine max (L.) Merr.), hydrogen peroxide, catalase, ascorbate peroxidase, guaiacol peroxidase, drought.


DNA Research ◽  
2008 ◽  
Vol 15 (4) ◽  
pp. 201-214 ◽  
Author(s):  
M. Wei ◽  
T. Yokoyama ◽  
K. Minamisawa ◽  
H. Mitsui ◽  
M. Itakura ◽  
...  

1992 ◽  
Vol 38 (6) ◽  
pp. 588-593 ◽  
Author(s):  
D. J. Hume ◽  
D. H. Blair

In the absence of Bradyrhizobium japonicum populations in the soil, yields of field-grown soybean (Glycine max (L.) Merrill) usually respond to inoculation with B. japonicum. The objective of this research was to determine the relationship between numbers of B. japonicum per seed in inoculants and soybean nodulation and yield. A total of six field experiments were conducted in 1989 and 1990 on new soybean soils. In dilution trials, Grip inoculant was applied to provide approximately 106, 105, 104, and 103B. japonicum per seed at two locations in 1989. Nodule number and mass, as well as seed yield, increased curvilinearly upward with increasing log10 most probable numbers (MPNs) of B. japonicum. The yield response curve was best fit by a cubic equation, which accounted for 97% of the variation in yield. Seed yields increased 19% (1.83 to 2.13 Mg/ha) from 105 to 106B. japonicum per seed. In field experiments involving 8 commercial inoculants in 1989 and 10 in 1990, and conducted at two locations in each year, responses to increasing log MPNs in the inoculants also were concave upwards and cubic. In the two years, 78 and 46% of the yield variation was accounted for by log MPN per seed. Increasing MPN per seed from 105 to 106 improved yields in first-time fields by an average of 24%, indicating the present minimum standard of 105B. japonicum per seed should be increased. Key words: most probable numbers, response to inoculation, nodulation, Glycine max (L.) Merrill.


Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 123-127 ◽  
Author(s):  
W. R. Azlin ◽  
C. G. McWhorter

Over a 4-yr period, glyphosate [N-(phosphonomethyl)glycine] was applied over-the-top to soybeans [Glycine max(L.) Merr.] at five rates, from 0.56 to 3.36 kg/ha, at four periods of time prior to harvest, 23 to 29 days, 15 to 21 days, 7 to 12 days, and 1 to 4 days. Soybean yields were reduced when glyphosate was applied at 2.24 and 3.36 kg/ha 23 to 29 days before harvest. Soybean seed were discolored following all five rates of glyphosate applied 23 to 29 days before harvest, following glyphosate at 1.12 to 3.36 kg/ha applied 15 to 21 days before harvest, and following glyphosate at 3.36 kg/ha applied 7 to 12 days before harvest. Germination of soybean seed was reduced at 30 C only when glyphosate was applied at 2.24 and 3.36 kg/ha 23 to 29 days before harvest, or at 3.36 kg/ha applied 15 to 21 days before harvest. At alternating temperatures (10.6 C for 72 h followed by 30 C for 72 h), all treatments applied 23 to 29 days before harvest reduced soybean seed germination; glyphosate at 1.12, 1.68, and 3.36 kg/ha applied 15 to 21 days before harvest also reduced germination. Seed from plots treated with glyphosate 23 to 29 or 15 to 21 days before harvest produced atypical soybean plants. Glyphosate at 2.24 and 3.36 kg/ha applied 23 to 29 days before harvest reduced the oil content in soybean seed, but none of the treatments consistently affected the protein content.


Sign in / Sign up

Export Citation Format

Share Document