Utility of Rhizobium in the phyllosphere of crop plants in nitrogen-free sand culture

1982 ◽  
Vol 98 (1) ◽  
pp. 167-171 ◽  
Author(s):  
A. S. Nandi ◽  
B. Sengupta ◽  
S. P. Sen

SUMMARYSoya bean, mung bean, Bengal gram and lentil grown in nitrogenless sand culture and sprayed with suspensions of different strains ofRhizobiumshowed increases in dry weight, chlorophyll and N-content. In a few cases the performance ofRhizobiumapplied to the phyllosphere was almost as good as a seed inoculation treatment. The beneficial effect of sprayingRhizobiumstrains was independent of the specificity of cross-inoculation groups. Nitrogenase activity as indicated by acetylene reduction by theRhizooium-leafassociation varied between 460 and 723 nmol/g leaf/h.

1982 ◽  
Vol 98 (1) ◽  
pp. 173-177 ◽  
Author(s):  
A. S. Nandi ◽  
B. Sengupta ◽  
S. P. Sen

SUMMARYSoya bean, Bengal gram and lentil plants were grown under field conditions and sprayed with suspensions of different strains ofRhizobium. Irrespective of crossinoculation groups beneficial effects were similar to those observed in nitrogen-free sand culture with respect to dry weight, chlorophyll and N contents. The beneficial effects of sprayingRhizobiumstrains compared favourably with seed treatment by appropriateRhizobiumstrains and application of urea. Both an ineffective strain and a mutant strain ofR. japonicumshowed similar beneficial effects. Acetylene reduction by theRhizobium-leafassociation ranged from 497 to 890 nmol/g leaf/h. The ectosymbiotic association ofRhizobiumwith foliage of legumes, thus, may meet to a large extent the nitrogen requirement of such plants.


1988 ◽  
Vol 110 (2) ◽  
pp. 321-329 ◽  
Author(s):  
R. Rai

SummaryHigh-temperature-adapted strains RAU 1, RAU 2 and RAU 3 ofAzospirillum brasilenseC 7 were isolated from stepwise transfer to higher temperature (30 to 42 °C). One of the strains (RAU 1) showed more growth, greater nitrogenase and hydrogenase activities at 30 and 42 °C than parental and other temperature-adapted strains. This strain also showed growth and more nitrogenase activity from pH 6·5 to 8·0. Strain RAU 1 showed cross-resistance to penicillin (300/µg/ml) but not to streptomycin, kanamycin, viomycin and polymixin B at 30 and 42 °C. It was demonstrated in field plots in calcareous soil that seed inoculation with RAU 1 enhanced mineral uptake of cheena. Inoculation with RAU 1 led to a significant increase in associative nitrogen fixation, dry weight of roots, grain and straw yield of cheena compared with the uninoculated control with or without applied N, but the effect of seed inoculation with high-temperature-adapted strains was variable with different genotypes of cheena.


1992 ◽  
Vol 38 (6) ◽  
pp. 577-583 ◽  
Author(s):  
J. K. Ladha ◽  
Minviluz Garcia ◽  
R. P. Pareek ◽  
G. Rarivoson

Six experiments, two each in the phytotron, greenhouse, and field, were conducted to assess the contribution of nitrogenase activity (acetylene reduction) by stem nodules in the presence and absence of root nodules of Sesbania rostrata (Brem & Oberm). In a greenhouse experiment, the effect of detaching already formed aerial stem nodules on the restoration of root nodules and nitrogenase activity was studied. The field experiment compared nodulation and acetylene-reduction activity by dual-nodulating S. rostrata and root-nodulating Sesbania cannabina. Acetylene-reduction activity expressed per gram of nodule dry weight was higher for stem nodules than for root nodules. Root nodule dry weight and acetylene-reduction activity failed to increase after stem inoculation, but root nodule dry weight and acetylene-reduction activity increased several fold within 15 days of detachment of aerial stem nodules. Stem nodulation, which occurred without inoculation under lowland field condition, suppressed root nodulation, thus accounting for more than 75% of total nitrogenase activity. Sesbania rostrata showed higher acetylene-reduction activity than S. cannabina. In dual-nodulating plants, root and stem nodules appeared to strike a balance in competition for energy, which may be controlled by stem nodulation. Key words: Sesbania rostrata, Azorhizobium caulinodans, stem nodule, root nodule, acetylene-reducing activity.


1986 ◽  
Vol 37 (3) ◽  
pp. 263 ◽  
Author(s):  
AM Alston ◽  
DW Puckridge

Barrel medic (cv. Jemalong) was grown on a red-brown earth at Adelaide to examine dry matter production and nitrogenase activity in relation to environmental conditions and carbon dioxide exchange. At 4-10-day intervals, measurements were made of dry weight and nitrogen content in plant parts, and mineral nitrogen content of the soil. Rates of acetylene reduction and carbon dioxide exchange, and environmental variables were measured. Curves fitted to data for solar radiation and carbon exchange rate were used to calculate daily values for net carbon dioxide uptake. Estimates of dry weight production derived from these net uptakes of carbon dioxide gave a similar curve to measured dry weight, but overestimated maximum dry weight by almost 20%. The difference is presumed to be due to materials lost from the roots. At maturity, dry weight and plant nitrogen content had declined by 10 and 14% respectively from their maxima of 1.02 kg m-2 and 26.1 g m-2 in October. All fractions of the plant except the litter and seed lost nitrogen. Rates of acetylene reduction reached a maximum of 39 mmol m-2 day-1 104 days from sowing, when the medic began to flower, and declined to almost zero by 145 days. At this time carbon dioxide exchange rates were high, and the plants were still accumulating nitrogen; from approximately 14 g N m-2 at day 104 to 24 g N m-2 at day 145. These changes are discussed in relation to environmental conditions and soil nitrogen content.


1987 ◽  
Vol 14 (5) ◽  
pp. 527 ◽  
Author(s):  
AD Day ◽  
GD Price ◽  
KA Schuller ◽  
PM Gresshoff

The nodule physiology of a supernodulating, nitrate tolerant symbiosis soybean (Glycine max (L.) Merr.) mutant (nts382) was compared to that of its wild-type parent, cv. Bragg. Nodule number and mass were greater in nts382 than cv. Bragg and individual nodule mass, bacteroid and haem content, and acetylene reduction activity per g nodule were less. Acetylene reduction activity expressed per mg bacteroid protein was the same in the two genotypes. In median sections, the ratio of infected to total nodule area was smaller in nts382, infected cell size was smaller and there were fewer bacteroids per peribacteroid envelope. When inoculum dose was decreased from 109 to 103 viable cells per pot, nodule number on nts382 decreased approximately to that on cv. Bragg; nodule size, bacteroid and haem contents increased as did nodule acetylene reduction activity. Application of moderate levels of nitrate, which did not significantly affect symbiotic parameters of cv. Bragg or high inoculum nts382, stimulated nodule growth and nitrogenase activity of low inoculum nts382. A combination of nitrate and low inoculum levels enhanced nodule parameters of nts382 to the level usually seen with cv. Bragg. When supernodulated, plant dry weight of nts382 was less than that of Bragg; decreasing inoculum dose had no significant effect but nitrate application increased plant growth; nitrate plus low inoculum induced similar plant growth to that of cv. Bragg. Nodule carbohydrate content was similar in both genotypes but nodule and xylem sap ureide contents were higher in nts382. In general, nodules of supernodulated nts382 resembled under-developed cv. Bragg nodules; when supernodulation was avoided by using low inoculum doses, ,nts382 nodules resembled those of cv. Bragg. Nitrogen metabolism in the mutant seems to be disturbed, resulting in ureide accumulation.


2018 ◽  
Vol 51 (3) ◽  
pp. 51-68 ◽  
Author(s):  
M.K. Hasan ◽  
M.S. Islam ◽  
M.R. Islam ◽  
H.N. Ismaan ◽  
A. El Sabagh

Abstract A laboratory experiment regarding germination and seedling growth test was conducted with three black gram genotypes tested under three salinity levels (0, 75 and 150 mM), for 10 days, in sand culture within small plastic pot, to investigate the germination and seedling growth characteristics. Different germination traits of all black gram genotypes, like germination percentage (GP), germination rate (GR), coefficient of velocity of germination (CVG) greatly reduced, as well as mean germination time (MGT) increased with increasing salt stress. At high salt stress, BARI Mash-3 provided the highest GP reduction (28.58%), while the lowest was recorded (15.79% to control) in BARI Mash-1. Salinity have the negative impact on shoot and root lengths, fresh and dry weights. The highest (50.32% to control) and lowest reduction (36.39%) of shoot length were recorded in BARI Mash-2 and BARI Mash-1, respectively, under 150 mM NaCl saline conditions. There were significant reduction of root lengths, root fresh and dry weight, shoot length, shoot fresh and dry weight in all genotypes under saline condition. The genotypes were arranged as BARI Mash-1 > BARI Mash-3 > BARI Mash-2, with respect to salinity tolerance.


1990 ◽  
Vol 17 (5) ◽  
pp. 489 ◽  
Author(s):  
Herdina ◽  
JH Silsbury

Methods of conducting acetylene reduction (AR) assay were appraised for estimating the nitrogenase activity of nodules of faba bean (Vicia faba L.). Factors considered were: (i) disturbance of plants when removing the rooting medium; (ii) assay temperature; (iii) the use of whole plants rather than detached, nodulated roots; (iv) diurnal variation in nodule activity; and (v) a decline in C2H4 production after exposure to C2H2. Plants growing in jars of 'oil dry' (calcined clay) had the same AR activity when assayed in situ in a closed system as when assayed after removal of the rooting medium. Assay temperatures of 12.5, 17.5 and 22.5°C influenced the specific rate of AR with the optimum at 17.5°C. Removal of the shoot resulted in a rapid decrease in AR activity in both vegetative and reproductive plants but the effect was much larger in the latter. AR and respiration by nodulated roots were closely linked and both varied markedly over a diurnal 12 h/12 h cycle. Since no fluctuation was found after nodules were detached, diurnal variation in the respiration of nodulated roots is attributed to change in nodule activity. Half of the dark respiration of nodulated roots was associated with respiration of the nodules and thus largely with N2 fixation. Since the AR assay provides no information on how electron flow in vivo is partitioned between reduction of N2 and reduction of protons, diurnal variation in hydrogen evolution (HE) in air and Ar/O2 in an open system was used to estimate this partitioning. Diurnal variation in apparent N2 fixation estimated in this manner was examined at a 'low' PPFD (300 μmol m-2 s-1) and at 'high' (1300 μmol m-2 s-1) to explore whether variation could be attributed to change in carbohydrate supply. Although HE in air and in Ar/O2 were both closely linked with the respiration of the nodulated root, apparent N2 fixation showed only a slight diurnal variation at 'low' light and almost none at 'high'. Vegetative plants showed no C2H2-induced decline in activity with exposure to C2H2 but reproductive plants did. This difference appears to be an age effect rather than attributable to flowering per se, since a decline occurred even when plants were kept vegetative by disbudding. A closed system for AR assay appears satisfactory for vegetative faba bean but such an assay over a 40-min period during the reproductive stage would underestimate nitrogenase activity by about 20%.


1983 ◽  
Vol 61 (11) ◽  
pp. 2956-2963 ◽  
Author(s):  
U. Granhall ◽  
T. Ericsson ◽  
M. Clarholm

The effects of single large or repeated, exponentially increasing applications of nutrients, with or without inorganic nitrogen and at two pH levels, on the growth, nodulation, acetylene reduction, and nutrient uptake in Alnus incana (L.) Moench were investigated in pot experiments with peat under controlled laboratory conditions. The repeated application of inorganic nitrogen did not suppress nitrogenase activity until the last 2 weeks, whereas an initial, large, nitrogen application effectively inhibited nodulation and activity throughout the 40-day experimental period. The mode of nitrogen application was thus found to be more important than the total amounts applied. Shoot length, leaf area, shoot–root relations, dry-matter production, and nitrogen contents of plants were determined at the end of the experiment, as well as the effect of Frankia inoculations. Nitrogenase activity was determined three times, at 0, 3, and 5 weeks. N2 fixation (balance/acetylene reduction) was found to be maximal, 55% of total nitrogen uptake, in minus-N pots with single applications of essential nutrients. The fastest growth was, however, noted in pots with single applications of all nutrients, including N. Among the latter, pots inoculated with Frankia showed the best growth, in spite of low nitrogenase activity. The only noticeable effect of a raised pH level was a reduced endophyte activity in minus-N pots with single applications of essential nutrients, due to increased N mineralization in the peat.


2016 ◽  
Vol 29 (4) ◽  
pp. 789-795 ◽  
Author(s):  
SALOMÃO LIMA GUIMARÃES ◽  
LAURA CRISTINA REZENDE DAS NEVES ◽  
EDNA MARIA BONFIM-SILVA ◽  
DANIELA TIAGO DA SILVA CAMPOS

ABSTRACT Pigeon pea is an important protein source grown in several tropical and sub-tropical countries, and is considered a multi-purpose plant that is resistant to the conditions of the Brazilian Cerrado. Among the possible uses for cowpea, its use as a green manure, increasing soil nitrogen content through the association with diazotrophic bacteria, generically known as rhizobia, is noteworthy. The present work aimed to evaluate the efficiency of Rhizobium strains isolated from cowpea plants in the development of pigeon peas cultured in Red Latosol. The experiment was conducted in a greenhouse, using a completely randomized design with seven treatments and four replications. Treatments consisted of inoculation with four Rhizobium strains (MT8, MT15, MT16, and MT23) and one commercial inoculant comprising Bradyrhizobium spp. strains BR 2801 and BR 2003. There were two controls, one absolute (without inoculation or nitrogen fertilization) and the other with nitrogen fertilization. Each experimental plot consisted of an 8-dm3 vase containing three plants. Analyzed variables included plant height, SPAD index, number and dry weight of nodules, and shoot and root dry masses. Pigeon peas responded significantly to inoculation treatment, since all the plants inoculated with Rhizobium strains isolated from cowpea strains showed results similar to plants in the nitrogen control and commercial inoculant treatments. This demonstrates a favorable plant-bacteria interaction, which can be utilized as an alternative nitrogen source for pigeon peas.


1981 ◽  
Vol 27 (1) ◽  
pp. 52-56 ◽  
Author(s):  
L. V. Wood ◽  
R. V. Klucas ◽  
R. C. Shearman

Turfs of 'Park' Kentucky bluegrass reestablished in the greenhouse and inoculated with Klebsiella pneumoniae (W6) showed significantly increased nitrogen fixation (acetylene reduction) compared with control turfs. Mean ethylene production rates per pot were 368 nmol h−1 for K. pneumoniae treated turfs, 55 nmol h−1 for heat-killed K. pneumoniae treated turfs, and 44 nmol h−1 for untreated turfs. Calculated lag periods before activity was observed were generally very short (less than 1 h).When 'Park' Kentucky bluegrass was grown from seed on soil-less medium of Turface, a fired aggregate clay, inoculation with K. pneumoniae (W6) resulted in 9 of 11 turfs showing nitrogenase activity (mean ethylene producion rate per pot was 195 nmol h−1). Only 3 of 11 turfs treated with heat-killed K. pneumoniae showed any activity and their mean rate of ethylene production (40 nmol h−1 per pot) was significantly lower than that for turfs treated with K. pneumoniae.Using the 'Park'–Turface soil-less model system it was shown that acetylene reducing activity was (i) root associated, (ii) generally highest at a depth of 1–4 cm below the surface, (iii) enhanced by washing excised roots, and (iv) inhibited by surface sterilization of excised roots. Klebsiella pneumoniae was recovered from Turface and roots showing acetylene reducing activity.


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