Response of ectomycorrhizal and nonmycorrhizal pitch pine (Pinusrigida) seedlings to nutrient supply and aluminum: growth and mineral nutrition

1996 ◽  
Vol 26 (12) ◽  
pp. 2145-2152 ◽  
Author(s):  
George A. Schier ◽  
Carolyn J. McQuattie

Mycorrhizal colonization and nutrient supply may have important effects on aluminum toxicity in trees grown on acidic, nutrient-poor soils. The interacting effects of mycorrhizal inoculation, nutrient level, and Al treatment on growth and mineral nutrition of pitch pine (Pinusrigida Mill.) seedlings grown with and without the ectomycorrhizal fungus Pisolithustinctorius (Pers.) Coker & Couch were determined. The seedlings were grown for 66 days in sand irrigated with 0.1- or 0.2-strength nutrient solution (pH 3.8) containing 0, 10, or 20 mg/L Al (0, 0.37, or 0.74 mM). Across nutrient and Al levels total dry weight of ectomycorrhizal (ECM) seedlings was 75% greater than that of nonmycorrhizal (NM) seedlings. Doubling the nutrient level increased the dry weight of NM seedlings by 120%, versus 60% for ECM seedlings. Aluminum reduced root and shoot growth in NM seedlings, but had no effect on shoot growth and only a marginally significant effect on root growth of ECM seedlings. Shoot growth of NM seedlings was more sensitive to Al than root growth. Increased growth of NM seedlings by doubling the nutrient level was least at the highest Al level. Symptoms of Al toxicity in roots (dark, stunted tips) occurred at a lower Al level in NM than ECM seedlings. A strong relationship was not found between Al toxicity and concentrations of Mg and Ca in roots and needles. Enhancement of growth resulting from increased uptake of nutrients due to mycorrhizal inoculation (and) or an increased level of nutrients was the overriding factor affecting the response of pitch pine seedlings to Al.

1992 ◽  
Vol 70 (7) ◽  
pp. 1488-1492 ◽  
Author(s):  
Peter Nosko ◽  
Kenneth A. Kershaw

Week-old white spruce seedlings were grown for 7 days at pH 4.5, 3.9, 3.65, or 3.5 using a continuous flow system to deliver experimental solutions. At each pH, seedlings received either no aluminum or 10 μM Al, a concentration 2 – 3 orders of magnitude lower than the reported minimum Al concentrations required to induce toxicity symptoms in seedlings of a variety of tree species. In – Al treatments, root elongation was reduced at pH 3.9 and root dry weight was reduced at pH 3.5, compared with seedlings grown at pH 4.5. Exposure to 10 μM Al caused further reduction of root growth, the magnitude of which increased as pH decreased. This suggests that seedling root growth was affected by the increased proportion of the total Al existing as phytotoxic Al3+ at lower pH values or by an interaction of Al3+ and H+. Neither pH nor Al affected shoot growth. Both acidity and Al could limit natural regeneration of white spruce by preventing seedling establishment. Key words: aluminum toxicity, soil acidity, forest decline, white spruce, Picea glauca, forest regeneration.


2015 ◽  
Vol 33 (3) ◽  
pp. 137-141
Author(s):  
Bruce R. Roberts ◽  
Chris Wolverton ◽  
Samantha West

The efficacy of treating soilless substrate with a commercial humectant was tested as a means of suppressing drought stress in 4-week-old container-grown Zinnia elegans Jacq. ‘Thumbelina’. The humectant was applied as a substrate amendment at concentrations of 0.0, 0.8, 1.6 and 3.2% by volume prior to withholding irrigation. An untreated, well-watered control was also included. The substrate of treated plants was allowed to dry until the foliage wilted, at which time the plants were harvested and the following measurements taken: number of days to wilt (DTW), xylem water potential (ψx), shoot growth (shoot dry weight, leaf area) and root growth (length, diameter, surface area, volume, dry weight). For drought-stressed plants grown in humectant-treated substrate at concentrations of 1.6 and 3.2%, DTW increased 25 and 33%, respectively. A linear decrease in ψx was observed as the concentration of humectant increased from 0.0 to 3.2%. Linear trends were also noted for both volumetric moisture content (positive) and evapotranspiration (negative) as the concentration of humectant increased. For non-irrigated, untreated plants, stress inhibited shoot growth more than root growth, resulting in a lower root:shoot ratio. For non-irrigated, humectant-treated plants, the length of fine, water-absorbing roots increased linearly as humectant concentration increased from 0.0 to 3.2%. Using humectant-amended substrates may be a management option for mitigating the symptoms of drought stress during the production of container-grown bedding plants such as Z. elegans.


2000 ◽  
Vol 51 (6) ◽  
pp. 701 ◽  
Author(s):  
C. L. Davies ◽  
D. W. Turner ◽  
M. Dracup

We studied the adaptation of narrow-leafed lupin (Lupinus angustifolius) and yellow lupin (L. luteus) to waterlogging because yellow lupin may have potential as a new legume crop for coarse-textured, acidic, waterlogging-prone areas in Western Australia. In a controlled environment, plants were waterlogged for 14 days at 28 or 56 days after sowing (DAS). Plants were more sensitive when waterlogged from 56 to 70 DAS than from 28 to 42 DAS, root growth was more sensitive than shoot growth, and leaf expansion was more sensitive than leaf dry weight accumulation. Waterlogging reduced the growth of narrow-leafed lupin (60–81%) more than that of yellow lupin (25–56%) and the response was more pronounced 2 weeks after waterlogging ceased than at the end of waterlogging. Waterlogging arrested net root growth in narrow-leafed lupin but not in yellow lupin, so that after 2 weeks of recovery the root dry weight of yellow lupin was the same as that of the control plants but in narrow-leafed lupin it was 62% less than the corresponding control plants. Both species produced equal amounts of hypocotyl root when waterlogged from 28 to 42 DAS but yellow lupin produced much greater amounts than narrow-leafed lupin when waterlogged from 56 to 70 DAS.


2018 ◽  
Vol 19 (10) ◽  
pp. 3073 ◽  
Author(s):  
Md. Rahman ◽  
Sang-Hoon Lee ◽  
Hee Ji ◽  
Ahmad Kabir ◽  
Chris Jones ◽  
...  

Aluminum (Al) toxicity is one of the major limitations that inhibit plant growth and development in acidic soils. In acidic soils (pH < 5.0), phototoxic-aluminum (Al3+) rapidly inhibits root growth, and subsequently affects water and nutrient uptake in plants. This review updates the existing knowledge concerning the role of mineral nutrition for alleviating Al toxicity in plants to acid soils. Here, we explored phosphorus (P) is more beneficial in plants under P-deficient, and Al toxic conditions. Exogenous P addition increased root respiration, plant growth, chlorophyll content, and dry matter yield. Calcium (Ca) amendment (liming) is effective for correcting soil acidity, and for alleviating Al toxicity. Magnesium (Mg) is able to prevent Al migration through the cytosolic plasma membrane in root tips. Sulfur (S) is recognized as a versatile element that alleviates several metals toxicity including Al. Moreover, silicon (Si), and other components such as industrial byproducts, hormones, organic acids, polyamines, biofertilizers, and biochars played promising roles for mitigating Al toxicity in plants. Furthermore, this review provides a comprehensive understanding of several new methods and low-cost effective strategies relevant to the exogenous application of mineral nutrition on Al toxicity mitigation. This information would be effective for further improvement of crop plants in acid soils.


1990 ◽  
Vol 20 (11) ◽  
pp. 1714-1719 ◽  
Author(s):  
George A. Schier ◽  
Carolyn J. McQuattie ◽  
Keith F. Jensen

Newly germimated pitch pine (Pinusrigida Mill.) seedlings inoculated with a mycorrhizal fungus (Pisolithustinctorius (Pers.) Coker & Couch) were grown for 13 weeks in sand irrigated with nutrient solution (pH 4.0) containing 0, 12.5, 25, 50, or 100 mg/L of aluminum (Al) in growth chambers fumigated with 0, 50, 100, or 200 ppb ozone. Increasing the concentration of ozone or Al caused increasing reductions in needle length, seedling height, and biomass of needles, stems, and roots. Significant ozone × Al interactions indicated that ozone and Al were interacting synergistically in reducing growth. Effect of treatments on the root/shoot ratio demonstrated that shoot growth was more sensitive to Al than root growth, whereas root growth was more sensitive to ozone. The concentration of most mineral elements (P, K, Ca, Mg, Mn, Cu, Zn) in needles was reduced by ozone or Al. Iron was the only element that increased with increasing concentrations of ozone or Al.


2006 ◽  
Vol 57 (7) ◽  
pp. 761 ◽  
Author(s):  
Eun-Young Choi ◽  
Ann McNeill ◽  
David Coventry ◽  
James Stangoulis

Within the semi-arid region of south-eastern Australia, high levels of subsoil boron (B) in alkaline soil can limit production of dryland crops. The aim of this research was to investigate the whole plant response to a range of subsoil-extractable B concentrations for a number of crop and weed species common to agricultural areas of South Australia. Specifically, the objectives were to determine (a) the morphological response of the entire root system to high subsoil B and (b) the available B concentrations in subsoil critical for expression of shoot traits commonly used in selection of B tolerance. Barley grass (Hordeum glaucum L.), crop barley (Hordeum vulgare) variety Clipper and breeders’ line VB9953, fababean (Vicia faba var. Fjiord), Lincoln weed (Diplotaxis tenuifolia L.), prickly lettuce (Lactuca serriola), and evening primrose (Oenothera stricta L.) were grown in sealed PVC cylinders (500 mm deep by 150 mm diam.) containing a sandy soil. The concentration of extractable B in the topsoil (0–0.20 m), considered non-toxic, was 0.5 mg/kg for all cylinders but a range of B treatments (0.5, 2.4, 4.3, 6.8, or 12.2 mg/kg) was applied directly to the subsoil (0.30–0.50 m). Increasing the concentration of extractable B in the subsoil decreased root dry weight in this region, but did not reduce water use from subsoil by barley grass or evening primrose. The response of the roots in the topsoil and subsequent responses in the shoot also differed among species. Symptoms of B toxicity in shoots of all the species were observed at subsoil-extractable B concentrations of 12.2 mg/kg and at lower concentrations in some of the crop and weed species. Shoot growth, total water use, and root growth in topsoil of Clipper and Lincoln weed were severely impaired by high subsoil-extractable B, as was topsoil root growth in evening primrose, with the reduction in the weed species being mostly associated with a decrease in taproot dry weight. Barley grass, VB9953, evening primrose, and to a lesser extent fababean and prickly lettuce, maintained shoot growth at all subsoil-extractable B concentrations, despite a reduction in subsoil water use by VB9953. Prickly lettuce and VB9953 also sustained root growth in the topsoil whilst fababean and barley grass increased root growth in the topsoil in response to high subsoil extractable B. There was no direct relationship between the quantity of B accumulated in shoots and detrimental effects on growth. Furthermore, there appeared to be no direct relationship between water uptake and B uptake since irrespective of the effect of subsoil B on either subsoil or total water use, shoot B concentration increased in all the species/genotypes as subsoil B increased. The degree to which plants were deemed to exhibit tolerance was, therefore, highly dependent upon the trait used for assessment. One suggestion in the current study is that shoot dry matter in B toxic soil can be a consistent parameter for considering varieties for tolerance to B toxicity.


2013 ◽  
Vol 37 (1) ◽  
pp. 177-187 ◽  
Author(s):  
Michelli Fernandes Batista ◽  
Ismar Sebastião Moscheta ◽  
Carlos Moacir Bonato ◽  
Marcelo Augusto Batista ◽  
Odair José Garcia de Almeida ◽  
...  

Aluminum (Al) toxicity is one of the most limiting factors for productivity. This research was carried out to assess the influence of Al nutrient solution on plant height, dry weight and morphoanatomical alterations in corn (Zea mays L.) roots and leaves. The experiment was conducted in a greenhouse with five treatments consisting of Al doses (0, 25, 75, 150, and 300 µmol L-1) and six replications. The solutions were constantly aerated, and the pH was initially adjusted to 4.3. The shoot dry matter, root dry matter and plant height decreased significantly with increasing Al concentrations. Compared to the control plants, it was observed that the root growth of corn plants in Al solutions was inhibited, there were fewer lateral roots and the development of the root system reduced. The leaf anatomy of plants grown in solutions containing 75 and 300 µmol L-1 Al differed in few aspects from the control plants. The leaf sheaths of the plants exposed to Al had a uniseriate epidermis coated with a thin cuticle layer, and the cells of both the epidermis and the cortex were less developed. In the vascular bundle, the metaxylem and protoxylem had no secondary walls, and the diameter of both was much smaller than of the control plants.


HortScience ◽  
2019 ◽  
Vol 54 (6) ◽  
pp. 1067-1076 ◽  
Author(s):  
Ryan C. Costello ◽  
Dan M. Sullivan ◽  
David R. Bryla ◽  
Bernadine C. Strik ◽  
James S. Owen

New markets for organic northern highbush blueberry (Vaccinium corymbosum L.) have stimulated interest in using composts specifically tailored to the plant’s edaphic requirements. Because composts are typically neutral to alkaline in pH (pH 7 to 8), and blueberry requires acidic soil (pH 4.2 to 5.5), we investigated elemental sulfur (S0) addition as a methodology for reducing compost pH. The objectives were to 1) characterize initial compost chemistry, including the pH buffering capacity of compost (acidity required to reduce pH to 5.0), 2) measure changes in compost chemistry accompanying acidification, and 3) evaluate plant growth and mineral nutrition of blueberry in soil amended with an untreated or acidified compost. Ten composts prepared from diverse feedstocks were obtained from municipalities and farms. Addition of finely ground S0 reduced compost pH from 7.2 to 5.3, on average, after 70 d at 22 °C, and increased the solubility of nutrients, including K (from 22 to 36 mmol(+)/L), Ca (from 5 to 19 mmol(+)/L), Mg (from 5 to 20 mmol(+)/L), and Na (from 6 to 9 mmol(+)/L). Sulfate-S, a product of S0 oxidation, also increased from 5 to 45 mmol(−)/L. The composts were incorporated into soil at a high rate (30% v/v) in a greenhouse trial to evaluate their suitability for use in blueberry production. Shoot and root growth were strongly affected by compost chemical characteristics, including pH and electrical conductivity (EC). Potassium in compost was highly variable (2–32 g·kg−1). Concentration of K in the leaves increased positively in response to compost K, whereas shoot dry weight and root growth declined. Leaf Mg also declined in response to compost K, suggesting that elevated K concentrations in compost may cause Mg deficiency. Composts with the highest K were also high in total N, pH, and EC. Compost acidification to pH ≤ 6 improved growth and increased leaf Mg concentration. On the basis of these results, composts derived from animal manures or young plant tissues (e.g., green leaves) appear to be unsuitable for high-rate applications to blueberry because they usually require high amounts of S0 for acidification and are often high in EC and K, whereas those derived from woody materials, such as local yard debris, appear promising based on their C:N ratio, compost acidification requirement, and EC.


Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 27-32
Author(s):  
Larry D. Knerr ◽  
Herbert J. Hopen ◽  
Nelson E. Balke

Laboratory studies demonstrated that naptalam safens cucumber against the phytotoxic effects of chloramben. In petri dish studies, cucumber seedlings grown from seeds exposed to chloramben plus naptalam had greater shoot growth, root growth, and dry weight than seedlings grown from seeds exposed to chloramben alone. Naptalam also partially reversed the reduction in dry weight of various plant parts caused by exposure of roots of hydroponically grown seedlings to chloramben. More radioactivity from root-applied14C-chloramben remained in cucumber roots and less was translocated to shoots with a14C-chloramben plus naptalam treatment than with a14C-chloramben alone treatment. Naptalam appeared to influence chloramben metabolism. In various plant parts, concentrations of chloramben and its metabolites differed between the two treatments.


2009 ◽  
Vol 33 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Ivo Ribeiro Silva ◽  
Tarcísio Fernando Cortes Corrêa ◽  
Roberto Ferreira Novais ◽  
T. Jot Smyth ◽  
Thomas Rufty ◽  
...  

The protective effect of cations, especially Ca and Mg, against aluminum (Al) rhizotoxicity has been extensively investigated in the last decades. The mechanisms by which the process occurs are however only beginning to be elucidated. Six experiments were carried out here to characterize the protective effect of Mg application in relation to timing, location and crop specificity: Experiment 1 - Protective effect of Mg compared to Ca; Experiment 2 - Protective effect of Mg on distinct root classes of 15 soybean genotypes; Experiment 3 - Effect of timing of Mg supply on the response of soybean cvs. to Al; Experiment 4 - Investigating whether the Mg protective effect is apoplastic or simplastic using a split-root system; Experiment 5 - Protective effect of Mg supplied in solution or foliar spraying, and Experiment 6 - Protective effect of Mg on Al rhizotoxicity in other crops. It was found that the addition of 50 mmol L-1 Mg to solutions containing toxic Al increased Al tolerance in 15 soybean cultivars. This caused soybean cultivars known as Al-sensitive to behave as if they were tolerant. The protective action of Mg seems to require constant Mg supply in the external medium. Supplying Mg up to 6 h after root exposition to Al was sufficient to maintain normal soybean root growth, but root growth was not recovered by Mg addition 12 h after Al treatments. Mg application to half of the root system not exposed to Al was not sufficient to prevent Al toxicity on the other half exposed to Al without Mg in rooting medium, indicating the existence of an external protection mechanism of Mg. Foliar spraying with Mg also failed to decrease Al toxicity, indicating a possible apoplastic role of Mg. The protective effect of Mg appeared to be soybean-specific since Mg supply did not substantially improve root elongation in sorghum, wheat, corn, cotton, rice, or snap bean when grown in the presence of toxic Al concentrations.


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