Tolerance of aluminium toxicity in annual Medicago species and lucerne

2008 ◽  
Vol 48 (4) ◽  
pp. 499 ◽  
Author(s):  
B. J. Scott ◽  
M. A. Ewing ◽  
R. Williams ◽  
A. W. Humphries ◽  
N. E. Coombes
Keyword(s):  
Average Length ◽  
Aluminium Toxicity ◽  
Solution Culture ◽  
Al Tolerance ◽  
Physiological Basis ◽  
Root Regrowth ◽  
Selection Intensities ◽  
Annual Medicago ◽  
Medicago Species ◽  
Relative Root

A rapid (7 day) solution-based screening test was developed using 15 annual Medicago cultivars and one M. sativa. Based on a relative root regrowth after exposures to aluminium (Al), Zodiac (M. murex), Orion (M. sphaerocarpos) and the M. polymorha cultivars Santiago, Cavalier and Serena had the greatest Al tolerance. Herald (M. littoralis) and Rivoli (M. tornata) were most sensitive. Ranking for Al tolerance from the solution culture correlated well (r = 0.80) with ranking for tolerance of the 16 genotypes grown in an acidic soil (unlimed pHCa 4.1). We screened 17 Australian populations of lucerne (M. sativa) using a 24 h ‘pulse’ of 75 µmol/L Al, and a three day ‘recovery’ of 10 µmol/L Al. We identified and recovered plants with a root regrowth of ≥5 mm in all 17 populations with selection intensities of 2 to 4%. Four of these selected populations (Aurora, UQL-1, A513 and TO2-011) were polycrossed within each population to produce four populations of seed from the cycle 1 selections. The length of root regrowth under Al stress was improved for all four populations of cycle 1 selection (P ≤ 0.001; from 2.6 mm for the original populations to 6.3 mm for the cycle 1 selections). In a subsequent experiment the cycle 2 selections from Aurora, UQL-1 and TO2-011 had significantly greater root regrowth than both the cycle 1 selections (P ≤ 0.001; 8.3 cf. 6.6 mm) and the unselected populations (3.0 mm). The selections from TO2-011 appeared to have greater improvement in the average length of root regrowth after 2 cycles of selection. Selected germplasm was more tolerant than GAAT in our evaluation. Based on estimation of realised heritability, it seemed likely that higher selection intensities would give more rapid improvements in tolerance. Our studies have not investigated the physiological basis of any tolerance of Al which we observed.

Comparative tolerance of sugarcane, navybean, soybean and maize to aluminium toxicity

1988 ◽  
Vol 39 (2) ◽  
pp. 171 ◽  
Author(s):  
SJ Hetherington ◽  
CJ Asher ◽  
FPC Blamey
Keyword(s):  
Root Length ◽  
Aluminium Toxicity ◽  
Solution Culture ◽  
The Other ◽  
Root Tip ◽  
Al Tolerance ◽  
Saccharum Spp ◽  
Wide Range ◽  
Length Data ◽  
Length Reduction

The aluminium (Al) tolerance of three sugarcane (Saccharum spp.) cultivars was compared with one cultivar each of navybean (Phaseolus vulgaris), soybean (Glycine max), and maize (Zea mays) in a short-term solution culture experiment. The experiment was conducted under closely controlled conditions of pH (adjusted daily to 4.2 � 0.02) and root temperature (28�C) over a wide range of Al levels expressed as the sum of activities of monomeric A1 species (mean +aAL mono 0, 4, 14, 54, and 222 8M). The three sugarcane cultivars, Q77, Q113 and Q117, were found to be considerably more tolerant of Al in solution than were the other three species. At 14 8M +aAL mono toxicity symptoms on the sugarcane roots were slight, but were well developed on the roots of the other three species. At 220 8M +aAL mono the distance from the root tip to the first visible lateral was reduced by 9-30% in the sugarcane cultivars compared with 79% in maize and navybean, and 91% in soybean. Interpolation of curves fitted to root length data indicated critical (i.e. 10% total root length reduction) +aAL mono of 11-21 8M for the sugarcane cultivars compared with 2.0 8M, 1.8 8M, and 1.0 8M for soybean, maize, and navybean, respectively. Implications for the management of sugarcane tand are discussed briefly.

Response of growth and nitrogen fixation to pod elimination of three annual Medicago species submitted to drought and subsequent recovery

2016 ◽  
Vol 96 (5) ◽  
pp. 757-764 ◽  
Author(s):  
Hossein Sadeghi ◽  
Farzaneh Fakhari
Keyword(s):  
Nitrogen Fixation ◽  
Drought Stress ◽  
Growth Parameters ◽  
Field Capacity ◽  
Physiological Basis ◽  
Subsequent Recovery ◽  
Randomized Design ◽  
Four Levels ◽  
Annual Medicago ◽  
Medicago Species

This research examined the effect of pod elimination on growth and N2 fixation ability in three annual Medicago species during drought stress and subsequent recovery. This study was carried out as a factorial experiment based on a completely randomized design with four replications. The treatments included annual Medicago species, presence or removal of the pod, and water stress at four levels: 100% (as a control), 80%, 60%, and 40% field capacity (FC) during the period of stress. The results showed that annual Medicago species can be considered as semi-drought tolerant species and their recovery ability from mild and moderate drought stress is relatively good. M. polymorpha performed better and showed higher recovery ability in comparison with other tested species. The results of this study showed that elimination of pods from annual Medicago species before sowing enhanced seedling performance under drought stress. However, the effect of pod elimination showed higher significance on growth parameters than nitrogen fixation. The information from this research would be useful for better understanding the physiological basis of changes in drought resistance, as well as targeted breeding programs, to improve the performance of annual Medicago species under conditions of limited or scarce water supply.

The effect of nitrogen supply on the early growth and nodulation of several annual Medicago species

1990 ◽  
Vol 41 (3) ◽  
pp. 489 ◽  
Author(s):  
MA Ewing ◽  
AD Robson
Keyword(s):  
Inorganic Nitrogen ◽  
Acid Soils ◽  
Early Growth ◽  
Solution Culture ◽  
Nitrogen Supply ◽  
Fixed Nitrogen ◽  
Nodule Number ◽  
Annual Medicago ◽  
Medicago Species ◽  
Nutrient Solutions

Differences in nodulation amongst species of annual Medicago (medics) on moderately acid soils could be explained by differences in response to the form or level of nitrogen supply. We compared the growth and bulk soil pH changes when four annual medic species (M. truncatula, M. littoralis, M. polymorpha and M. murex) were supplied with ammonium, nitrate or biologically fixed nitrogen. Growth and nodule number were measured for M. polymorpha grown in solution culture at constant nitrogen supply (1 mM) but variable ammonium to nitrate ratio (1:0, 3:1, 1:1, 1:3, 0:1). Similar measurements were also made on M. truncatula, M. polymorpha and M. murex exposed to different concentrations of nitrate (0, 0.1, 1.5, 10 mM) during nodulation. When uninoculated, all medic species grew at the same rate when given equivalent levels of inorganic nitrogen as either ammonium or nitrate. All species similarly decreased the pH of soil around their roots when supplied with ammonium, and increased pH when supplied with nitrate. Nutrient solutions were acidified when M. polymorpha was supplied with ammonium and neutralized when nitrate was supplied. However, when ammonium and nitrate were added simultaneously solutions acidified, indicating a more rapid uptake of ammonium than nitrate. Nodule number of all medic species was reduced by nitrate concentrations in solution as low as 0.1 mM. M. truncatula formed fewer nodules than M. polymorpha and M. murex at all concentrations of nitrate.

Phytotoxicity of aluminium to wheat plants in high-pH solutions

2003 ◽  
Vol 43 (5) ◽  
pp. 497 ◽  
Author(s):  
G. Ma ◽  
P. Rengasamy ◽  
A. J. Rathjen
Keyword(s):  
South Australia ◽  
Acid Soils ◽  
Aluminium Toxicity ◽  
Solution Culture ◽  
Alkaline Solutions ◽  
Carbonate Solutions ◽  
Soil Solutions ◽  
Bicarbonate Solutions ◽  
Aluminium Species ◽  
Relative Root

Phytotoxicity of aluminium in acid soils is well known. At pH ≥6.3, aluminate [Al(OH)4–] is the principal hydroxo-aluminium species in soil solutions; however, its phytotoxicity has not received much attention. Sodic subsoils in Australia are generally alkaline and have pH above 9. During our survey of 8 subsoils in South Australia, we found aluminate ions at concentrations greater than 0.8 mg/L (29.7 μmol/L of aluminium) in soil solutions when pH was greater than 9, with corresponding high uptake of aluminium by wheat plants. We studied the phytotoxicity of aluminium to wheat plants in solution culture by maintaining the pH of alkaline solutions at 9.2.Relative root lengths of wheat plants, compared with those in reverse-osmosis deionised water, were significantly reduced in alkaline solutions and CO2-free air indicated toxicity of hydroxy, carbonate and bicarbonate ions. Further reduction of root lengths due to aluminate toxicity was also evident. Relative root lengths of wheat plants, when comparing between +aluminium and –aluminium treatments, were reduced up to 50% in alkaline solutions containing as low as 1 mg/L of aluminium. Aluminium accumulated mainly in the roots, thereby reducing their growth. In bicarbonate solutions, aluminium toxicity under alkaline pH was highly significant (P<0.001). However, at the same level of added aluminium in carbonate solutions, relative root length was not reduced. This study concludes that when aluminium species are present at a concentration of about 1 mg/L in soil solutions with pH greater than 9, the growth of wheat plants could be significantly affected.

Differential tolerance of manganese among cultivars of Triticum aestivum

1989 ◽  
Vol 67 (5) ◽  
pp. 1305-1308 ◽  
Author(s):  
Sheila M. Macfie ◽  
Gregory J. Taylor ◽  
Keith G. Briggs ◽  
John Hoddinott
Keyword(s):  
Triticum Aestivum ◽  
Root Growth ◽  
Solution Culture ◽  
High Yield ◽  
Root Weight ◽  
Al Tolerance ◽  
Control Root ◽  
Relative Root Growth ◽  
Maximum Root ◽  
Relative Root

Thirty cultivars of Triticum aestivum differed in tolerance of manganese (Mn) as determined by relative root growth in solution culture. Based upon a root weight index (RWI = root weight in the presence of 500 μM Mn divided by control root weight), Mn tolerance ranged from 0.08 to 0.88. All Canadian Western Red Spring (CWRS) cultivars tested were Mn sensitive. Cultivars bred for high yield were more Mn tolerant, especially 'Norquay' (RWI = 0.88) which was the only cultivar with a RWI > 0.70. The cultivars 'Norquay' and 'Columbus' were selected as standards for Mn tolerance and Mn sensitivity, respectively. 'Norquay' showed maximum root growth at 100 μM Mn, a concentration which was toxic to 'Columbus', and differential tolerance was maintained up to 1000 μM Mn in solution. Differences between 'Norquay' and 'Columbus', grown in excess Mn, were also observed in the accumulation of biomass with time. In contrast with previous studies, Mn tolerance was positively correlated with Al tolerance (R2 = 32.7, p = 0.001) in the cultivars tested.

Evaluation of solution culture techniques for studying aluminium toxicity in plants

1991 ◽  
pp. 905-912 ◽  
Author(s):  
F. P. C. Blamey ◽  
D. C. Edmeades ◽  
C. J. Asher ◽  
D. G. Edwards ◽  
D. M. Wheeler
Keyword(s):  
Aluminium Toxicity ◽  
Solution Culture ◽  
Culture Techniques

scholarly journals Differential expression of TLP, ERF1, and R2R3MYB in annual Medicago species under salinity conditions

2015 ◽  
Vol 14 (3) ◽  
pp. 10152-10164 ◽  
Author(s):  
F. Gharaghani ◽  
F. Rafiei ◽  
N. Mirakhorli ◽  
E. Ebrahimie
Keyword(s):  
Differential Expression ◽  
Annual Medicago ◽  
Medicago Species

An improved method for artificial hybridization in annual Medicago species

1994 ◽  
Vol 45 (7) ◽  
pp. 1329 ◽  
Author(s):  
W Pathipanawat ◽  
RAC Jones ◽  
K Sivasithamparam
Keyword(s):  
Success Rate ◽  
Fold Increase ◽  
Modified Technique ◽  
Established Method ◽  
Artificial Hybridization ◽  
Annual Medicago ◽  
Improved Technique ◽  
Medicago Species ◽  
First Time ◽  
Selection Of

An improved technique for successful artificial hybridization in annual medic (Medicago spp.) is described. Using a previously reported method, only four out of seven species were successfully crossed, with the percentage of success ranging from 3 to 22%. Initial modifications to this technique gave a 7-8 fold increase in the successful crossing rate in M. murex and M. polymorpha medic, from 9 to 64% with M. murex and from 10 to 82% with M. polymorpha. Further modifications to the technique resulted in a success rate of 100% in both species. The numbers of seeds per pod obtained from crosses in both species were also increased by using the modified techniques compared to the established method. Selection of larger, more mature flowers, differences in flower cutting position, as well as post pollination position were the main modifications which accounted for the greatly improved success rate. The modified technique was subsequently applied successfully to obtain for the first time inter-specific crosses involving M. polymorphax M. murex, M. polymorphax M. sphaerocarpos, M.murexx M. sphaerocarpos, M. solerolii x M. littoralis/M.truncatula hybrid, M. solerolii x M, tornata, and M. littoralis/M.truncatula hybrid x M. sphaerocarpos.

Strategies for control of Phoma black stem in annual Medicago species

1989 ◽  
Vol 29 (5) ◽  
pp. 635 ◽  
Author(s):  
MJ Barbetti
Keyword(s):  
Disease Severity ◽  
Medicago Truncatula ◽  
Field Trial ◽  
Subsequent Development ◽  
Field Site ◽  
Infected Seed ◽  
Annual Medicago ◽  
And Control ◽  
Medicago Species ◽  
Selection Of

Strategies for control of Phoma black stem disease in annual Medicago species through selection of cultivars with increased resistance to Phoma medicaginis, fungicidal spray applications to swards, and fungicidal control of seedborne infection, were investigated. Fiftyseven annual Medicago cultivars and lines were screened for resistance in the field in 1 m rows over 2 consecutive seasons. There were significant differences in resistance among species and also between lines and cultivars of any particular species. Three M. rugosa cultivars were very highly resistant and most cultivars and lines showed some resistance. In a field trial, the fungicides benomyl, carbendazim, flutriafol, propiconazole, thiabendazole and triadimefon were tested for their efficacy in controlling Phoma black stem disease. All fungicides reduced disease severity in the sward and, except for thiabendazole, the percentage burrs with Phoma lesions. The role and control of seed-borne P. medicaginis in causing Phoma black stem disease in Medicago truncatula and M. polymorpha var. brevispina at a field site was also investigated. Seed-borne P. medicaginis caused subsequent development of Phoma black stem disease in swards sown with infected seed. Disease appeared earlier, developed faster and became much more severe in M. truncatula cv. Cyprus than in M. polymorpha cv. Serena. Application of benomyl seed treatments (0.1 and 0.5% w/w) resulted in only a 4-5 week delay in the onset of Phoma black stem symptoms.

Characterization of manganese use efficiency in UK wheat cultivars grown in a solution culture system and in the field

2005 ◽  
Vol 143 (2-3) ◽  
pp. 151-160 ◽  
Author(s):  
W. Z. JIANG ◽  
C. R. IRELAND
Keyword(s):  
Spring Wheat ◽  
Crop Improvement ◽  
Dry Weight ◽  
Solution Culture ◽  
Dry Matter Accumulation ◽  
Wheat Cultivars ◽  
Apparent Quantum Yield ◽  
Physiological Basis ◽  
Use Efficiency ◽  
Wheat Lines

The aim of the research was to describe and characterize the physiological basis of Mn use efficiency among a range of old and modern UK wheat cultivars grown in Mn-depleted solution culture and to ascertain whether the existence of Mn use efficiency conferred a yield advantage under manganese stress conditions in the field. Results of solution culture experiments demonstrated that the old spring wheat cv. Maris Butler is relatively Mn efficient when grown in Mn-deficient conditions in comparison with both a modern winter wheat, cv. Claire, and a modern spring wheat, cv. Paragon. The mean dry weight gain of plants of cv. Maris Butler grown in Mn-depleted nutrient solution was 0·49 of that shown by plants in Mn-sufficient culture, whereas in cvs. Paragon and Claire the equivalent values were 0·38 and 0·21 respectively. When grown in Mn-deficient soil in a farm-based field trial, cv. Maris Butler showed significantly improved (P<0·05) dry matter accumulation and grain yield compared with other spring wheats including cv. Paragon. There was no significant variation in leaf Mn content between the cultivars examined, either under sufficient or depleted Mn supply; however, cv. Maris Butler showed both a relatively high maximum light-saturated rate of photosynthesis and a high photosynthetic apparent quantum yield (based on O2 evolution) when grown under Mn deficiency. It is argued that the apparent Mn use efficiency of cv. Maris Butler is related to superior internal utilization of Mn, resulting in an increased photosynthetic photosytem II efficiency rather than improved Mn uptake and accumulation. The results suggest that the wheat cultivar Maris Butler may provide a potentially useful source of parental material for future crop improvement programmes designed to produce wheat lines resistant to depleted Mn supply.

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