Glyphosate reduced seed and leaf concentrations of calcium, manganese, magnesium, and iron in non-glyphosate resistant soybean

Greenhouse experiments were conducted to study the effects of glyphosate drift on plant growth and concentrations of mineral nutrients in leaves and seeds of non-glyphosate resistant soybean plants (Glycine max, L.). Glyphosate was sprayed on plant shoots at increasing rates between 0.06 and 1.2% of the recommended application rate forweed control. In an experiment with 3-week-old plants, increasing application of glyphosate on shoots significantly reduced chlorophyll concentration of the young leaves and shoots dry weight, particularly the young parts of plants. Concentration of shikimate due to increasing glyphosate rates was nearly 2-fold for older leaves and 16-fold for younger leaves compared to the control plants without glyphosate spray. Among the mineral nutrients analyzed, the leaf concentrations of potassium (K), phosphorus (P), copper (Cu) and zinc (Zn) were not affected, or even increased significantly in case of P and Cu in young leaves by glyphosate, while the concentrations of calcium (Ca), manganese (Mn) and magnesium (Mg) were reduced, particularly in young leaves. In the case of Fe, leaf concentrations showed a tendency to be reduced by glyphosate. In the second experiment harvested at the grain maturation, glyphosate application did not reduce the seed concentrations of nitrogen (N), K, P, Zn and Cu. Even, at the highest application rate of glyphosate, seed concentrations of N, K, Zn and Cuwere increased by glyphosate. By contrast, the seed concentrations of Ca, Mg, Fe and Mn were significantly reduced by glyphosate. These results suggested that glyphosatemay interfere with uptake and retranslocation of Ca, Mg, Fe and Mn, most probably by binding and thus immobilizing them. The decreases in seed concentration of Fe, Mn, Ca and Mg by glyphosate are very specific, and may affect seed quality

Grain zinc, iron and protein concentrations and zinc-efficiency in wild emmer wheat under contrasting irrigation regimes

Micronutrient malnutrition, and particularly deficiency in zinc (Zn) and iron (Fe), afflicts over three billion people worldwide, and nearly half of the world’s cereal-growing area is affected by soil Zn deficiency. Wild emmer wheat [Triticum turgidum ssp. dicoccoides (Körn.) Thell.], the progenitor of domesticated durum wheat and bread wheat, offers a valuable source of economically important genetic diversity including grain mineral concentrations. Twenty two wild emmer wheat accessions, representing a wide range of drought resistance capacity, as well as two durum wheat cultivars were examined under two contrasting irrigation regimes (well-watered control and water-limited), for grain yield, total biomass production and grain Zn, Fe and protein concentrations. The wild emmer accessions exhibited high genetic diversity for yield and grain Zn, Fe and protein concentrations under both irrigation regimes, with a considerable potential for improvement of the cultivated wheat. Grain Zn, Fe and protein concentrations were positively correlated with one another. Although irrigation regime significantly affected ranking of genotypes, a few wild emmer accessions were identified for their advantage over durum wheat, having consistently higher grain Zn (e.g., 125 mg kg−1), Fe (85 mg kg−1) and protein (250 g kg−1) concentrations and high yield capacity. Plants grown from seeds originated from both irrigation regimes were also examined for Zn efficiency (Zn deficiency tolerance) on a Zn-deficient calcareous soil. Zinc efficiency, expressed as the ratio of shoot dry matter production under Zn deficiency to Zn fertilization, showed large genetic variation among the genotypes tested. The source of seeds from maternal plants grown under both irrigation regimes had very little effect on Zn efficiency. Several wild emmer accessions revealed combination of high Zn efficiency and drought stress resistance. The results indicate high genetic potential of wild emmer wheat to improve grain Zn, Fe and protein concentrations, Zn deficiency tolerance and drought resistance in cultivated wheat

Foliar-applied glyphosate substantially reduced uptake and transport of iron and manganese in sunflower (helianthus annuus L.) plants

Evidence clearly shows that cationic micronutrients in spray solutions reduce the herbicidal effectiveness of glyphosate for weed control due to the formation of metal-glyphosate complexes. The formation of these glyphosate-metal complexes in plant tissue may also impair micronutrient nutrition of nontarget plants when exposed to glyphosate drift or glyphosate residues in soil. In the present study, the effects of simulated glyphosate drift on plant growth and uptake, translocation, and accumulation (tissue concentration) of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were investigated in sunflower ( Helianthus annuusL.) plants grown in nutrient solution under controlled environmental conditions. Glyphosate was sprayed on plant shoots at different rates between 1.25 and 6.0% of the recommended dosage (i.e., 0.39 and 1.89 mM glyphosate isopropylamine salt). Glyphosate applications significantly decreased root and shoot dry matter production and chlorophyll concentrations of young leaves and shoot tips. The basal parts of the youngest leaves and shoot tips were severely chlorotic. These effects became apparent within 48 h after the glyphosate spray. Glyphosate also caused substantial decreases in leaf concentration of Fe and Mn while the concentration of Zn and Cu was less affected. In short-term uptake experiments with radiolabeled Fe (59Fe), Mn (54Mn), and Zn (65Zn), root uptake of 59Fe and 54Mn was significantly reduced in 12 and 24 h after application of 6% of the recommended dosage of glyphosate, respectively. Glyphosate resulted in almost complete inhibition of root-to-shoot translocation of 59Fe within 12 h and 54Mn within 24 h after application. These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate-metal complexes in plant tissues and/or rhizosphere interactions

Glyphosate inhibition of ferric reductase activity in iron deficient sunflower roots

Iron (Fe) deficiency is increasingly being observed in cropping systems with frequent glyphosate applications. A likely reason for this is that glyphosate interferes with root uptake of Fe by inhibiting ferric reductase in roots required for Fe acquisition by dicot and nongrass species. This study investigated the role of drift rates of glyphosate (0.32, 0.95 or 1.89 mM glyphosate corresponding to 1, 3 and 6% of the recommended herbicidal dose, respectively) on ferric reductase activity of sunflower (Helianthus annuus) roots grown under Fe deficiency conditions. Application of 1.89 mM glyphosate resulted in almost 50% inhibition of ferric reductase within 6 h and complete inhibition 24 h after the treatment. Even at lower rates of glyphosate (e.g. 0.32 mM and 0.95 mM), ferric reductase was inhibited. Soluble sugar concentration and the NAD(P)H oxidizing capacity of apical roots were not decreased by the glyphosate applications. To our knowledge, this is the first study reporting the effects of glyphosate on ferric reductase activity. The nature of the inhibitory effect of glyphosate on ferric reductase could not be identified. Impaired ferric reductase could be a major reason for the increasingly observed Fe deficiency in cropping systems associated with widespread glyphosate usage

Heavy metal accumulation in Artemisia and foliaceous lichen species from the Azerbaijan flora

Artemisia plants and foliaceous lichens are known to be capable of accumulating heavy metals (HM) from soil and air. These plant species are widespread on polluted sites of Azerbaijan. However, so far their capacity to accumulate HM in their shoots and roots has not been tested. Three Artemisia and two lichen species were collected from different contaminated sites of Azerbaijan. Plant and surface soil samples were measured for Cd, Cu, Pb, Ni and Zn concentrations by ICP-AES.The results indicated that among the Artemisia species A. scoparia showed the best HM accumulation properties. Lichen species were also distinguished by very high amounts of HM in their biomass, while in surrounding soil samples HM concentrations had higher contents than the soils occupied only with Artemisia species.The results indicate that on contaminated sites Artemisia and lichens accumulated metals in their biomass without toxicity symptoms. Taking large biomass and high adaptation ability into account, A. scoparia represents a good tool for a phytoremediation approach on polluted soils

Effects of Different Forms and Doses of Sulphur Application on Wheat

Deficiency of sulphur (S) is an important limiting factor of plant growth for sustainable agricultural production. The decline in sulphur dioxide emission, decrease in S-containing fertilizer consumption due to the high cost of S-fertilizers, breeding of new high yielding species are the well known causes of S-deficiency. A greenhouse experiment was conducted to investigate the effects of several doses of K2SO4-S, CaSO4-S and elemental-S applied on growth, shoot dry matter yield, S and N concentrations of wheat cultivar. The experiments were conducted in three soils differed from available S concentrations. Effects of different S-treatments (0, 25, 50 and 100 mg S kg-1) and S-forms had significant effects on shoot dry matter yields of plants. Sulphur from different S-sources did not increase shoot S-concentrations in Eskisehir and Konya soils, but increase was significant obtained in the Harran soil. Shoot S-concentration in Harran soil for zero K2SO4 treatment was 0.09%, the values were 0.22, 0.26 and 0.27% respectively for 25, 50 and 100 mg kg-1 treatments. The results indicated significant effects of S-treatments on plant growth and yield mostly based on soil properties, especially the available S-level

Fosfor eksikliğine dayanıklı domates genotiplerinin belirlenmesi ve etkinlik mekanizmalarının morfolojik ve fizyolojik açıdan karakterize edilmesi

TEZ6360Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2007.Kaynakça (s.61-71) var.xi, 72 s. : res. ; 29 cm.Low levels of available P in soils limit the plant production. Although total P concentrations are generally high in soils, because of some soil characteristics (low and high pH, high CaCO3, low organic matter etc.) in soils, it might be fixed in unavailable forms. Under P-limiting conditions, plants have developed some adaptation mechanisms such as changes in root morphology, increased root exudates, enhanced releases of acid phosphatase and phytase, increased root uptake of P, to survive. Because of these reasons, it can be thought that selection and cultivation of P efficient species and cultivars of a species might be very helpful for both economical and environmental aspects. In this PhD study, there was very large variation among P efficiency values of tomato genotypes. The most distinct differences between P-efficient and P-inefficient cultivars were shoot and root growth and P content under P-limiting conditions. At low P supply, P concentration in shoot was similar in all cultivars. However, it has been observed that, in sensitive cultivars, antosian accumulation in the leaves which appears in reddish-purple colour, was much higher. In the experiment dealing with the possible role of P uptake in P efficiency of tomato cultivars, it has been found that among the plants pre-cultured with low P, there was a good relation between P uptake and P efficiency of the genotypes used in this experiment. It is just to say that the Pefficient cultivars took almost 30% more P up and had higher P absorption rates than the P-inefficient cultivars. In the experiments conducted to see the role of possible physiological traits of plants such as acid phosphatase and phytase activities of roots, although the activities of both enzymes were increased under P limiting conditions, no relation was found between them and P efficiency of genotypes.Topraklarda bitkilere yarayışlı P konsantrasyonun düşük olması bitkisel üretimi sınırlamaktadır Topraklarda toplam P miktarı oldukça fazla olmakla birlikte bir takım toprak özelliklerinden (düşük veya yüksek pH, yüksek CaCO3, yetersiz organik madde vs.) gibi etmenlerden dolayı P toprakta bitkilerin kolayca yararlanamayacağı bileşiklere dönüşmektedir. Bitkiler yetersiz P koşulları altında kök sistemlerinde değişim, kök salgılarında artış, APA ve fitaz salgı aktivitelerinde atış, yüksek absorpsiyon kapasitesi gibi bir takım adaptasyon mekanizmaları geliştirebilmektedir. Bu nedenlerden dolayı, fosfor etkinliği yüksek bitki tür ve çeşitlerinin tarımsal üretim alanlarında yer alması, hem ekonomik hem de çevresel anlamda önemli faydalar sağlayacaktır. Bu tez çalışmasında, test edilen domates genotiplerinin P etkinliği oldukça geniş bir varyasyon göstermiştir. Fosfor etkinliği düşük ve yüksek bulunan çeşitler arasındaki en önemli farkın, düşük P uygulamasındaki yeşil aksam ve kök kuru madde verimi, fosfor içeriği olduğu saptanmıştır. Düşük P koşullarında yeşil aksamda P konsantrasyonun çeşitler arasında büyük benzerlik göstermiştir. Buna karşı bitki P eksiklik simptomu olan ve yeşil aksamda morarmalar şeklinde oluşan antosiyanin birikiminin duyarlı genotiplerde oldukça fazla düzeyde olduğu belirlenmiştir. Fosfor absorpsiyonu ile ilgili olarak yürütülen denemede, farklı P etkinliğine sahip çeşitlerin düşük P koşullarında P absorpsiyonu ve P absorpsiyon hızlarının P etkinliği ile ilişkili olduğu belirlenmiştir. Fosfor etkin olan genotiplerin duyarlı genotiplere göre ortalama %30 daha fazla P absorpsiyon kapasitelerinin olduğu ve P absorpsiyon hızlarının da daha fazla olduğu görülmüştür. Fosfor etkinliğindeki farklılıklardan sorumlu olabilecek bitkisel özelliklerin araştırıldığı denemelerde, P eksikliği koşullarında, köklerin APA (asit fosfataz) ve fitaz enzim aktiviteleri yeterli P koşullarına göre önemli düzeyde arttığı, ancak, söz konusu özellikler açısından çeşitler arasında farklılığın olmadığı belirlenmiştir.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi Tarafından Desteklenmiştir. Proje No

Effects of potassium, magnesium, and sulphur containing fertilizers on yield and quality of sugar beets (Beta vulgaris L.)

Effects of potassium (K), magnesium (Mg), and sulphur (S) containing fertilizers on root yield, refined sugar yield, and K, Mg, and S concentrations of leaf of sugar beet (Beta vulgaris L.) were studied on 3 different locations in Konya province, namely Kuzucu, Karaarslan, and Alakova, in 2004, 2005, and 2006. In the trails, a uniform diammonium phosphate (DAP) + urea application was used as the control treatment, while potassium sulphate and Mg containing Kalimagnesia, were applied at varying rate combinations. Compared to the control treatment (DAP + urea), all fertilizer treatments containing K, Mg, and S increased root yield in the Kuzucu and Alakova locations, while in the Karararslan location only potassium sulphate treatment improved root yield. The Kalimagnesia fertilizer containing all 3 nutrients, namely K, Mg, and S, enhanced root yield by 42% and 39% in the Kuzucu and Alakova locations, respectively. But, this yield-stimulating effect of the Kalimagnesia fertilizer was rate-dependent. Kalimagnesia was also effective in improving the sugar content of the root, while the amino-N levels were not consistently affected by the fertilizer treatments. Despite increases in the leaf concentrations of K, Mg, and S by the tested fertilizers, the changes in the leaf concentrations of these nutrients could not fully explain the increases in root yields. In the discussion of the results, the possible role of basic cation saturation ratios of soils was also taken into consideration. The results indicate that a fertilizer treatment including 81 kg K2O ha(-1), 27 kg Mg ha(-1), and 46 kg S ha(-1) may be recommendable in fertilization of sugar beets, together with regular nitrogen and phosphorus applications, under similar conditions, in order to achieve a balanced mineral nutrition and sustain better root and sugar yields

Genotypic Variation in Tolerance to Boron Toxicity in 70 Durum Wheat Genotypes

By using 70 durum wheat (Triticum durum) genotypes, a greenhouse experiment has been carried out to study genotypic variation in tolerance to boron (B) toxicity in soil. Plants were grown in a soil containing 12 mg extractable B kg-1 soil and treated additionally with (+B: 25 mg kg-1 soil) and without B (-B: 0 mg B kg-1 soil). Following 30 days of growth, only shoots have been harvested and analyzed for dry matter production and shoot concentrations of B. There was a large genotypic variation in tolerance to B toxicity based on the severity of leaf symptoms and decreases in dry matter production caused by B toxicity. Among the genotypes tested, the growth of the genotypes Sabil-1, Stn “S”, Aconhi-89 and Wadelmez-2 was not affected; even, there was a tendency for an increase in growth by B treatment. By contrast, the dry matter production of all other genotypes was markedly decreased by the applied B, particularly in the genotypes Lagost-3, Dicle-74, Brachoua/134xS-61 and Gerbrach. In case of the genotypes Brachoua/134xS-61 and Gerbrach, B application reduced dry weight of the plants by 2-fold. Interestingly, there was no relationship between shoot B concentrations and relative decreases in shoot dry weight by B toxicity. The most B-sensitive genotypes had generally much lower amount of B in shoot than the genotypes showing higher tolerance to B toxicity. This result indicates that the B-exclusion mechanism is not involved in differential expression of B tolerance within 70 durum wheat genotypes. It seems very likely that the internal mechanisms (e.g., adsorption to cell walls and compartementation of B in vacuoles) could be a more plausible explanation for B tolerance in the durum wheats tested in the present study