Tolerance of Trifolium subterraneum cultivars to low pH

1985 ◽  
Vol 36 (4) ◽  
pp. 569 ◽  
Author(s):  
MK Kim ◽  
DG Edwards ◽  
CJ Asher
Keyword(s):  
Phosphorus Uptake ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Solution Culture ◽  
Nutrient Concentrations ◽  
Solution Ph ◽  
Ph Values ◽  
Phosphorus Absorption ◽  
Constant Ph ◽  
Effects Of Ph

Eleven cultivars of Trifolium subterraneum and Trifolium semipilosum cv. Safari were grown with adequate combined nitrogen for 27 days in flowing solution culture with controlled nutrient concentrations at constant pH values ranging from 3.5 to 6.5. A solution pH of 3.5 was lethal to all cultivars, but growth was in all cases vigorous at pH 4.0 (RGR 15.2-16.9 g 100 g-1 day-1). There were no significant effects of pH over the range of 4.0-6.5 on the yield of any clover cultivar. The results are discussed in relation to an earlier study suggesting greater tolerance of subterranean clover to pH values below 4.0. Phosphorus toxicity symptoms developed in all subterranean clover cultivars with the intensity of symptom development increasing with solution pH from 4.5 to 6.5. The concentration of phosphorus in the older leaves decreased as the solution pH was increased from 4.0 to 4.5, and then increased with further increase in pH, reaching values = 1.0%. Rates of phosphorus absorption followed a similar pattern of response to solution pH. Results are discussed with reference to previously reported effects of pH on phosphorus uptake.

Effects of pH and aluminium on the growth of temperate pasture species. I. Temperate grasses and legumes supplied with inorganic nitrogen

1991 ◽  
Vol 42 (3) ◽  
pp. 559 ◽  
Author(s):  
DC Edmeades ◽  
FPC Blamey ◽  
CJ Asher ◽  
DG Edwards
Keyword(s):  
White Clover ◽  
Festuca Arundinacea ◽  
Trifolium Pratense ◽  
Inorganic Nitrogen ◽  
Red Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Solution Culture ◽  
Pasture Legumes ◽  
Effects Of Ph

A flowing solution culture experiment was conducted in which four temperature pasture grasses and 11 temperate pasture legumes were grown in solutions of low ionic strength for 29 days at six aluminium (Al) levels with average Al3+ activities {Al3+} of 1.0, 5.1, 5.9, 9.9, 20.8, 41.6 8M at pH 4.5. Growth of these species was also measured at pH 5.5 in the absence of Al. In the absence of added Al, lucerne (Medicago sativa) cv. Hunter River and phalaris (Phalaris aquatica) cv. Grasslands Maru grew better at pH 5.5 than at 4.5. The reverse was so for ryegrass (Lolium perenne) cv. Grasslands Nui and subterranean clover (Trifolium subterraneum) cv. Tallarook. Increasing the pH from 4.5 to 5.5 had no effect on the growth of the other 11 species and cultivars tested. Micromolar activities of Al (<10 8M) markedly reduced the growth of all species. Four groups were tentatively identified in terms of their tolerance to Al. The two cultivars of ryegrass and the two red clover (Trifolium pratense) cultivars, together with Lotus corniculatus cv. Maitland, were relatively sensitive to Al. A 50% reduction in total dry matter (TDM) was associated with {Al3+} of 2-3 8M. The four white clover (Trifolium repens) cultivars, tall fescue (Festuca arundinacea) cv. Grasslands Roa, phalaris cv. Grasslands Maru, and Lucerne cv. Hunter River were intermediate in their tolerance, with {Al3+} of 3-5 8M reducing TDM by 50%. The two subterranean clover cultivars were more tolerant to Al than white clover (50% TDM reduction at 5-6 8M {Al3+}. Lotus pedunculatus CV. Grasslands Maku was exceptional in its tolerance to Al. Its growth was unaffected by {Al3+} up to 5 8M and 50% growth reduction was associated with {Al3+} of 7 8M The results of this study emphasize the need to conduct solution culture experiments at realistic solution concentrations and ionic strengths when examining the effects of Al on plant growth.

scholarly journals Adsorption of Lysozyme Into a Charged Confining Pore

2021 ◽  
Author(s):  
Sidney Carvalho ◽  
Ralf Metzler ◽  
Andrey Cherstvy ◽  
Daniel Caetano
Keyword(s):  
Electrostatic Interactions ◽  
Active Sites ◽  
Coarse Grained ◽  
Pore Surface ◽  
Solution Ph ◽  
Coarse Grained Model ◽  
Egg White Lysozyme ◽  
Constant Ph ◽  
Pka Shift ◽  
Effects Of Ph

Several applications arise from the confinement of proteins on surfaces since their stability and biological activity are enhanced. It is also known that the way a protein adsorbs on the surface is important for its biological function since its active sites should not be obstructed. In this study, the adsorption properties of hen egg-white Lysozyme, HEWL, into a negatively charged silica pore is examined employing a coarse-grained model and constant-pH Monte Carlo simulations. The role of electrostatic interactions is taken into account when including the Debye-Hueckel potentials into the Ca structure-based model. We evaluate the effects of pH, salt concentration, and pore radius on the protein preferential orientation and spatial distribution of its residues regarding the pore surface. By mapping the residues that stay closer to the pore surface, we find the increase of pH leads to orientational changes of the adsorbed protein when the solution pH gets closer to the HEWL isoelectric point. At these conditions, the pKa shift of these important residues caused by the adsorption into the charged confining surface results in a HEWL charge distribution that stabilizes the adsorption in the observed protein orientation. We compare our observations to the results of pKa shift for HEWL available in the literature and to some experimental data.

Comparison of single superphosphate and superphosphate coated with bauxite residue for subterranean clover production on phosphorus-leaching soils

Soil Research ◽  
2000 ◽  
Vol 38 (3) ◽  
pp. 735 ◽  
Author(s):  
Robert Summers ◽  
Martin Clarke ◽  
Tim Pope ◽  
Tim O'Dea
Keyword(s):  
Field Experiment ◽  
Soil Phosphorus ◽  
Bauxite Residue ◽  
Phosphorus Uptake ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Single Superphosphate ◽  
Glasshouse Experiment ◽  
The Impact ◽  
Coated Granules

Bauxite residue from alumina refining was used to coat granules of single superphosphate to reduce the leaching of phosphorus in coarse, sandy soils for pastures in high rainfall areas of south-western Australia (>800 mm annual average). The impact of coating the superphosphate on the leaching of phosphorus was measured in a glasshouse experiment and the effectiveness of the fertiliser using dry herbage yield of subterranean clover (Trifolium subterraneum) was measured in a field experiment. The glasshouse experiment measured the effect of coating the superphosphate with bauxite residue at 0, 5, 10, 15, 20, 25, 30, 35, and 40% by weight. A coating of 25% (by weight) was chosen for the field experiment. In the glasshouse experiment, the coated granules were applied to columns of soil, where subterranean clover was grown under leaching conditions. A coating of 30%, by weight, reduced leaching of single superphosphate by about half. Increasing the coating of bauxite residue also increased the phosphorus uptake and increased the plant growth. In the field trial, the effectiveness of single superphosphate with a bauxite residue coating of 25% by weight was increased on average by 100% in Year 1, 303% in Year 2, and 158% in Year 3, relative to freshly applied single superphosphate. The bauxite residue coating also increased the phosphorus content of the herbage in a similar manner to the increases in yield. Limited soil phosphorus tests showed only minor increases in the residues of phosphorus where the superphosphate had been coated with bauxite residue.

Nutrient problems in sown pasture on an acid soil. 2. Role of lime and superphosphate

1980 ◽  
Vol 20 (106) ◽  
pp. 568 ◽  
Author(s):  
KD McLachlan
Keyword(s):  
Plant Growth ◽  
Acid Soil ◽  
Phosphorus Uptake ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Titratable Acidity ◽  
Yield Response ◽  
P 16 ◽  
Exchangeable Magnesium

A study was made of the role of superphosphate and lime on subterranean clover (Trifolium subterraneum) production on an infertile acid soil in pot culture. Both fertilizers increased the exchangeable calcium in this deficient soil. Lime and superphosphate were involved in nodulation of the clover plants. There was no evidence of the direct involvement of either of them in the nitrogen fixation process, but they did increase nitrogen uptake by the plants. Once the legume functioned adequately, full expression of the yield response to phosphorus on this deficient soil followed. Most efficient phosphorus use occurred at the lime 1255, superphosphate 2000 kg ha-1 level (lime 1/2, P 16). Heavy lime dressing reduced exchangeable magnesium and the phosphorus available to the plant. Aluminium and pH were involved in the effects observed. Lime reduced CaCl2-extractable aluminium and the titratable acidity in the soil. Phosphate increased the CaCl2-extractable aluminium and apparently reduced the titratable aluminium. The combined treatments reduced these three attributes and promoted increased plant growth. Increased plant growth was associated with increased aluminium uptake by the plants, which suggests that the real effect of aluminium may have been on the calcium and phosphorus uptake by the plants, rather than on the toxic nature of the element itself.

Effects of pH and aluminium on the growth of temperate pasture species. II. Growth and nodulation of legumes

1991 ◽  
Vol 42 (5) ◽  
pp. 893 ◽  
Author(s):  
DC Edmeades ◽  
FPC Blamey ◽  
CJ Asher ◽  
DG Edwards
Keyword(s):  
White Clover ◽  
Trifolium Pratense ◽  
Inorganic Nitrogen ◽  
Red Clover ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Lotus Corniculatus ◽  
Culture Solution ◽  
Solution Ph ◽  
Lotus Pedunculatus

Ten temperate pasture legumes inoculated with appropriate rhizobia were grown for 31 days in flowing solution culture. Solution ionic strength was approximately 2700 8M and contained inorganic nitrogen (150 , 8M NO3-) only at the commencement of the experiment. Solution pH was maintained at 4.5, 5.0, 5.5 and 6.0. Also, five aluminium (Al) treatments were imposed, with nominal Al concentrations of 0, 3, 6, 12 and 24 8M (2.5, 7.1, 8.3, 11.2 and 24.7 8M Al measured) at pH 4.5. Solution pH <6 . 0 markedly reduced total dry mass (TDM) in all cultivars of white clover (Trifolium repens) cvv. 'Grasslands Pitau, Huia, G18 and Tahora' and red clover (Trifolium pratense) cvv. 'Grassland Turoa and Pawera', and to a lesser extent in the two subterranean clover (Trifolium subterraneum) cvv. 'Tallarook and Woogenellup'. In contrast, solution pH had no effect on the growth of Lotus corniculatus cv. Maitland, while Lotus pedunculatus cv. Maku grew best at pH 4.5. Lotus pedunculatus cv. Maku grew best in solution where the sum of the activities of the monomeric Al species {Alm} was maintained at 5.9 8M. The growth of all other species was decreased with Al in solution, a 50% reduction in TDM being associated with c. 6 8M {Alm] for white clover and subterranean clover, and c. 3 8M in red clover and Lotus corniculatus cv. Maitland.

scholarly journals Tuber Initiation in Hydroponically Grown Potatoes by Alteration of Solution pH

HortScience ◽  
1994 ◽  
Vol 29 (6) ◽  
pp. 621-623 ◽  
Author(s):  
Waylen Y. Wan ◽  
Weixing Cao ◽  
Theodore W. Tibbitts
Keyword(s):  
Tissue Culture ◽  
Mineral Composition ◽  
Nutrient Solution ◽  
Solution Culture ◽  
Tuber Initiation ◽  
Solution Ph ◽  
Constant Ph ◽  
Leaf Tissues ◽  
Hydroponically Grown ◽  
Potato Plantlets

Because tuberization in potatoes (Solarium tuberosum L.) reportedly is inhibited when stolons are immersed in liquid, this study was conducted to determine the effect of intermittent pH reductions of the nutrient solution on tuber induction of potatoes in solution culture. Tissue-culture potato plantlets were transplanted into solutions maintained at pH 5.5. The pH of the nutrient solution was changed to 3.5 and 4.0 for 10 hours on each of three dates (30, 35, and 40 days after transplanting). For the pH 3.5 treatment, tubers were observed first on day 42 and averaged 140 tubers per plant at harvest on day 54. For the pH 4.0 treatment, tubers were observed first on day 48 and averaged 40 tubers per plant at harvest. At a constant pH 5.5, tubers were observed on day 52 and averaged two tubers per plant at harvest. Plants with the intermittent pH 3.5 had smaller shoots and roots with shorter and thicker stolons compared to constant pH 5.5. With the intermittent pH 4.0, plants were of similar size, but stolons were shorter and slightly thickener compared to those from pH 5.5. Mineral composition of leaf tissues at harvest was similar for the three pH treatments. These results indicate that regulation of solution pH can be a useful technique for inducing tuberization in potatoes.

Effects of calcium supply on uptake of calcium and selected mineral nutrients by tropical food legumes in solution culture

1989 ◽  
Vol 40 (5) ◽  
pp. 1003 ◽  
Author(s):  
RW Bell ◽  
DG Edwards ◽  
CJ Asher
Keyword(s):  
Calcium Concentration ◽  
Inorganic Nitrogen ◽  
Maximum Growth ◽  
Calcium Deficiency ◽  
Solution Culture ◽  
Nutrient Concentrations ◽  
Phosphorus Absorption ◽  
Food Legumes ◽  
Arachis Hypogaea L ◽  
Low Concentrations

Six tropical food legumes, peanut (Arachis hypogaea (L.) cv. Red Spanish), pigeonpea (Cajanus cajan (L.) Millsp. cv. Royes), guar (Cyarnopsis tetragonoloba (L.) Taub. cv. Brooks), soybean (Glycine max (L.) Merr. cv. Fitzroy), and cowpea (Vigna unguiculuta (L.) Walp. cv. Vita 4 and CPI 282 15) were grown for 20 days at six constant solution calcium concentrations (2, 12, 50, 100,500 and 2500 8M ) in flowing solution culture at pH 5.5 � 0.1, with adequate inorganic nitrogen and controlled basal nutrient concentrations. Increases in solution calcium concentration from 2 to 12 8M generally increased rates of absorption of nitrogen, phosphorus, potassium, manganese and zinc, and rates of transport of magnesium and iron to plant tops. These increases in nutrient absorption and transport rates were associated with the alleviation of severe calcium deficiency. Further increases in solution calcium concentration from 12 to 2500 8M generally had no effect on potassium absorption rate, but increased absorption rates of nitrogen (by 20-130%), and phosphorus (by 90-500%), and decreased those of manganese and zinc; it also decreased rates of transport of iron and magnesium to plant tops. With guar, rates of phosphorus absorption at <2500 8M calcium were too low to maintain adequate concentrations of phosphorus in tops for maximum growth. With the remaining legumes, rates of zinc absorption at 12 8M calcium were high enough for plants to accumulate excessive concentrations of zinc (347-479 mg kg-1) in their tops. These results are discussed in relation to the adaptation of tropical food legumes to soils with low concentrations of calcium in the soil solution and the response of legumes to calcium or lime applications.

Distribution of magnesium in subterranean clover (Trifolium subterraneum L.) in relation to supply

1990 ◽  
Vol 41 (3) ◽  
pp. 499 ◽  
Author(s):  
BJ Scott ◽  
AD Robson
Keyword(s):  
Plant Growth ◽  
Shoot Growth ◽  
Leaf Tissue ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Solution Culture ◽  
Tissue Concentrations ◽  
Deficiency Symptoms ◽  
Young Leaves ◽  
Supply Current

The objectives of this study were to examine Mg distribution in subterranean clover (Trifolium subterraneum L.), to identify an appropriate tissue for diagnosis of deficiency and to establish minimum tissue concentrations associated with maximum plant growth. Plants were grown in solution culture with both discontinued (40 8M and 160 8M reduced to nil) and constant supply (0, 5, 10, 20, 40, 80, 160 8M Mg). Magnesium was depleted from old leaves when Mg supply to the roots was interrupted. However, deficiency symptoms occurred first on the young tissue under these conditions. Under constant but inadequate supply, initial deficiency symptoms occurred in old tissue. Symptoms in leaves were associated with Mg concentrations in the leaf of < 1046 8g g-1 with constant root supply and 586 8g g-1 when supply was interrupted. At luxury constant supply, concentrations of Mg tended to be higher in the older leaves than in the young leaves; the reverse occurred with inadequate supply. Tissue choice for diagnosis was not critical, but the minimum Mg concentration in tissue commensurate with maximum shoot growth varied from 740 8g g-1 for the unifoliate leaf to 1310 8g g-1 in the youngest open leaf (YOL), when plants were grown under constant Mg supply. Current supply of Mg to roots was reflected more rapidly in the concentrations in young leaf than in old leaf tissue.

Nutrient potential and capacity. III. Minimum value of potassium potential for availability to Trifolium subterraneum in soil and in solution culture

1967 ◽  
Vol 18 (1) ◽  
pp. 55 ◽  
Author(s):  
NJ Barrow ◽  
CJ Asher ◽  
PG Ozanne
Keyword(s):  
Fine Root ◽  
Plant Root ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Solution Culture ◽  
Buffering Capacity ◽  
Free Energy Of Exchange ◽  
Solution Cultures ◽  
Very High ◽  
Nutrient Solutions

Plants of subterranean clover (Trifolium subterraneum L.) were grown in a range of soils until the supplies of potassium were exhausted. The potassium potential of each soil was then measured by determining the free energy of exchange of potassium for calcium plus magnesium. In soils of very high buffering capacity the potassium potential of the exhausted soil was about –6000 cal/equiv. In soils of lower buffering capacity the potential of the exhausted soil was higher but this may have been an artefact due to release of potassium from fine root material left in the soil at harvest. Subterranean clover plants were also grown in large volumes of well-stirred nutrient solutions which were held at a range of potassium concentrations. Again it was found that the plants were unable to take up potassium when the potassium potential was about –6000 cal/equiv. It is suggested that the potentials were similar because diffusion gradients were negligible in the exhausted soil and also in the swiftly flowing solutions. At potentials above –6000 cal/equiv. availability of potassium appeared to be greater in the solution cultures than in soils. It is suggested that this occurred because, in soils, the uptake of potassium causes the potential at the plant root to be lower than in the bulk of the soil.

scholarly journals Effects of pH and Trace Minerals on Long-Term Starvation of Leuconostoc mesenteroides

2000 ◽  
Vol 66 (3) ◽  
pp. 976-981 ◽  
Author(s):  
Dong-Shik Kim ◽  
Steven Thomas ◽  
H. Scott Fogler
Keyword(s):  
Cell Viability ◽  
Decay Rate ◽  
Leuconostoc Mesenteroides ◽  
Trace Minerals ◽  
Solution Ph ◽  
Decay Rate Constant ◽  
Ph Values ◽  
Wide Range ◽  
Effects Of Ph ◽  
Starvation Conditions

ABSTRACT Laboratory experiments have definitively shown that exopolymer-producing bacteria have the potential to modify the flow of fluids in oil reservoirs to enhance oil production. Once injected into the reservoir, they will be subjected to a wide range of pH values and to starvation resulting from nutrient depletion. For successful field implementation it is necessary to have a fundamental understanding of these effects on the viability of bacteria. This paper addresses the effects of pH and trace minerals on cell viability of Leuconostoc mesenteroides during carbon source depletion. Two different carbon sources were used to grow cells before transferring the cells to starvation conditions: sucrose and a combination of glucose and fructose. These substrates were chosen because L. mesenteroides produces a significant amount of water-insoluble exopolymers (dextran) under sucrose-fed conditions, which may enhance cell survival under harsh conditions. The effects of dextran on the cell viability were tested at different pH values with and without trace minerals. The rate of cell death followed an exponential-decay law for different values of the solution pH. The optimal solution pH for survival was pH 5, whereas cells died rapidly at pH 3 and below and at pH 13 and above. The sucrose-fed cells showed a greater viability than cells fed glucose and fructose for all pH ranges tested. The results indicated that water-insoluble exopolymers help cells survive for longer periods of time under starvation conditions. The effects of trace minerals on cell culturability were tested at two pH values, 4.5 and 7. For both cases, cells showed a greater culturability (smaller decay rate constant) in the presence of trace minerals than without trace minerals. It was also found that the effects of trace minerals on cell culturability were greater for glucose-fructose-fed cells than for sucrose-fed cells. The Michaelis pH function theory was used for comparing the relationships between the cell decay rate and pH.

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