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Bioavailability of Chlorpyrifos in Wheat Plants (Triticum aestivun)  [PDF]
Sylvia V. Copaja, Rosa Vergara, Héctor R. Bravo
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.58069
Abstract:

Adsorption processes of chlorpyrifos in two Chilean agro soils (Calera: C; San Esteban: SE) in relation with the bioaccumulation in wheat plants (Triticum aestivun) were studied. RP-HPLC method was developed to determine the chlorpyrifos content in soils, roots and seedling tissues. The two soils showed high adsorption capacity (C = 78%, SE = 92%). The values are not in relation with the contents of organic matter (C = 3.9% and SE = 2.0%) and clay (C = 12.7% and SE = 10.1%) determined in the soils. Persistence and mobility of chlorpyrifos in the soils were estimated from halflife values (Csoil = 23 d, SEsoil = 14 d) and the Guss index (Csoil = 0.89, SEsoil = 0.25) respectively. These values are in the range of non-leaching compounds, and suggest that there should be no pollutant in the ground water. Wheat plants grown in both soils incubated with chlorpyrifos bioaccumulate residues in roots and seedling tissues. Root tissues showed the greatest contents (C = 22.3 mg/k. f. wt; SE = 51.8 mg/kg. f. wt.). Germination and growth of wheat young plants were not inhibited for the contents in the tissues. A relation between the levels of chlorpyrifos residues in the soils and the bioaccumulation in wheat tissues was estimated from the BAI parameter. Values showed that the bioaccumulation is dependent on the residues contents in soils. These results suggest that bioavailability of chlorpyrifos in wheat plants may be a harmful pollutant for mammals if it remains stable at all growth stage of the plant. Further research should be considered to see if bioavailability in forage and/or grain can occur.

Potassium applied under drought improves physiological and nutrient uptake performances of wheat (Triticum Aestivun L.)  [cached]
M. A Samar Raza,M Farrukh Saleem,G Mustafa Shah,M Jamil
Journal of Soil Science and Plant Nutrition , 2013,
Abstract: The physiological and nutrient uptake performance of two wheat (Triticum aestivum L.) cultivars (Lasani-2008 and Auqab-2000) to foliar application of 1% potassium (K) at three different growth stages (tillering, flower initiation and grain filling) was investigated under water limited environment in a wire house experiment at the Nuclear Institute for Agriculture and Biology, Faisalabad. The aim was to find out the best K application stage for improvement in drought tolerance potential. Drought stress was created by withholding irrigation at the three growth stages and then K was sprayed with carboxymethyl cellulose as a sticking agent, whereas Tween-20 was used as a surfactant for foliar spray. At maturity, aboveground nitrogen, phosphorus, K, sodium and calcium uptakes by the crop were measured. Besides, water potential, osmotic potential and turgor potential of crop were also estimated. The results indicated that the drought stress at all three critical growth stages of wheat adversely affected plant's nutrient uptake, water potential, osmotic potential and turgor potential of wheat plants. The exogenous application of K under drought stress at all three critical growth stages enhanced tolerance of wheat by reducing toxic nutrient's uptake and improving the physiological efficiency. In this regards, both varieties showed uniform behavior. Maximum improvement in all the recorded nutrients uptake and physiological parameters was achieved when K was applied at grain filling stage of both cultivars.
PREDICTION OF BIOAVAILABILITY OF CHLORPYRIFOS RESIDUES IN SOIL TO EARTHWORMS
Wu,X.M; Yu,Y.L; Li,M; Long,Y.H; Fang,H; Li,S.N;
Journal of soil science and plant nutrition , 2011, DOI: 10.4067/S0718-95162011000100004
Abstract: an incubation test was conducted to investigate the effect of aging on bioavailability of chlorpyrifos in soil and to assess the feasibility of chemical extraction techniques for predicting bioavailability of chlorpyrifos in soil. chlorpyrifos was spiked into sterilized soil and aged in microcosms for up to 120 days. the earthworms were incubated in the spiked soils, at 0, 7, 14, 30, 60, and 120 days after spiking, for a period of 7 days. after exposure, chlorpyrifos concentrations in the earthworm tissues were determined. change in chemical extractability of soil-chlorpyrifos was measured using a several solvent systems including methanol, methanol-water (9:1), acetone-water (5:3), and water. the results show that chemical extractability and earthworm bioavailability of chlorpyrifos in soil decreased with aging. the amount of aged and unaged chlorpyrifos recovered from soil varied with the individual chemical extractant and extraction method. concentrations of chlorpyrifos in eisenia foetida were significantly higher than in allolobophora caliginosa, suggesting that the bioavailability of chlorpyrifos was a species-dependent process. the extractability of chlorpyrifos by chemical solvents was significantly correlated with bioavailability fraction of e. foetida and a. caliginosa, showing that these extraction techniques may be efficient for predicting bioavailability of chlorpyrifos in soil.
PREDICTION OF BIOAVAILABILITY OF CHLORPYRIFOS RESIDUES IN SOIL TO EARTHWORMS  [cached]
X.M Wu,Y.L Yu,M Li,Y.H Long
Journal of Soil Science and Plant Nutrition , 2011,
Abstract: An incubation test was conducted to investigate the effect of aging on bioavailability of chlorpyrifos in soil and to assess the feasibility of chemical extraction techniques for predicting bioavailability of chlorpyrifos in soil. Chlorpyrifos was spiked into sterilized soil and aged in microcosms for up to 120 days. The earthworms were incubated in the spiked soils, at 0, 7, 14, 30, 60, and 120 days after spiking, for a period of 7 days. After exposure, chlorpyrifos concentrations in the earthworm tissues were determined. Change in chemical extractability of soil-chlorpyrifos was measured using a several solvent systems including methanol, methanol-water (9:1), acetone-water (5:3), and water. The results show that chemical extractability and earthworm bioavailability of chlorpyrifos in soil decreased with aging. The amount of aged and unaged chlorpyrifos recovered from soil varied with the individual chemical extractant and extraction method. Concentrations of chlorpyrifos in Eisenia foetida were significantly higher than in Allolobophora caliginosa, suggesting that the bioavailability of chlorpyrifos was a species-dependent process. The extractability of chlorpyrifos by chemical solvents was significantly correlated with bioavailability fraction of E. foetida and A. caliginosa, showing that these extraction techniques may be efficient for predicting bioavailability of chlorpyrifos in soil.
Effects of Soil pH Value on the Bioavailability and Fractionation of Rare Earth Elements in Wheat Seedling (Triticum aestivum L.)
土壤酸度对稀土元素在小麦体内的生物可利用性及分馏效应的影响

Cao Xinde,Ding Zhuhong,Hu Xin,Wang Xiaorong,
曹心德
,丁竹红,胡忻,王晓蓉

环境科学 , 2002,
Abstract: The effect of soil pH value on the bioavailability and fractionation of rare earth elements (REEs) in wheat seedling ( Triticum aestivum L.) were investigated. The results showed that the concentration of REEs in wheat decreased with increasing pH value, and their inter relationship was best expressed as quadratic equation, with correlation coefficients from 0.6003 to 0.9572. The response of individual elements to pH value change tended to be Ce>La>Nd>Sm> Gd>Yb>Eu, with Ce most sensitive to changing pH conditions and Eu lest. Chemical fractionation indicated that the order of REEs concentration in three fractions could be as follows: B2(NH2OH·HCl extraction)>B3(H2O2 NH4Ac extract)>B1(HAc extract). The increase of pH value resulted in transformation from B1 to B2 and B3. Multiple regression analysis was utilized to obtain the regression equations for prediction plant uptake of REEs. B1 fraction was most available to wheat. Meanwhile, it was found that the fractionation factors of REEs in wheat were negatively correlated with the soil pH value.
ECONOMIC EFFICIENCY OF THE WINTER WHEAT (TRITICUM AESTIVUM L.) AND WINTER SPELT (TRITICUM SPELTA L.) GROWING IN ORGANIC FARMING
J. ?RáMEK,P. KONVALINA,I. ZDRHOVá,J. MOUDRY jr.
Lucr?ri ?tiin?ifice : Management Agricol , 2009,
Abstract: Comparison of economic efectivity of the winter wheat (Triticum aestivum L.) and winter spelt (Triticum spelta L.) growing in organic farming systems. The differences of yield of two species wheats in organic farming system and factors are evaluated. In relation to standart technological procedures in farming systems are defined costs for area nad for production unit. Structure of costs on production, price differences between the winter wheat and winter spelt are analysed.
EFFECTS OF THE DIFFENTIAL CADMIUM COMPOUNDS AND THEIR INTERACTION ON THE WHEAT (Triticum aestivun L.)
不同化合形态镉、锌及其复合污染对小麦生理的影响

Yu Guo-Ying,
余国莹
,吴玉树,王焕校

生态学报 , 1992,
Abstract:
PCR-Based EST Mapping in Wheat (Triticum aestivum L.)
TATIK CHIKMAWATI,MIFTAHUDIN,J. PERRY GUSTAFSON
Biodiversitas , 2009,
Abstract: Mapping expressed sequence tags (ESTs) to hexaploid wheat is aimed to reveal the structure and function of the hexaploid wheat genome. Sixty eight ESTs representing 26 genes were mapped into all seven homologous chromosome groups of wheat (Triticum aestivum L) using a polymerase chain reaction technique. The majority of the ESTs were mapped to homologous chromosome group 2, and the least were mapped to homologous chromosome group 6. Comparative analysis between the EST map from this study and the EST map based on RFLPs showed 14 genes that have been mapped by both approaches were mapped to the same arm of the same homologous chromosome, which indicated that using PCR-based ESTs was a reliable approach in mapping ESTs in hexaploid wheat.
Chromosome sorting and its applications in common wheat (Triticum aestivum) genome sequencing
SuoWei Wu,Yang Xiao,Xu Zheng,YingFan Cai,Jaroslav Dole el,BingHua Liu,Li Yang,MeiFang Song,Peng Zhou,Yang Zhou,FanHua Meng,ShanHong Wang,HongWei Liu,HuQu Zhai,JianPing Yang
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-3106-7
Abstract: The large genome size (~17000 Mb) and complicated DNA structures of common wheat (Triticum aestivum) hamper its genome sequencing. By means of flow cytometry, systematic investigations on individual chromosome sorting have been carried out to construct chromosome-specific bacterial artificial chromosome (BAC) libraries since the 1980s. Several wheat chromo-some-specific BAC libraries, such as chromosome 3B, three D genome chromosomes (1D, 4D and 6D), and the short arm of chromosome 1B, have been developed, and the physical map of chromosome 3B was established in 2008. The same chromosome-based strategy is being employed by the International Wheat Genome Sequencing Consortium (IWGSC) to establish the physical maps of the other 20 common wheat chromosomes (cv. Chinese Spring). Several projects on wheat genome sequencing are currently underway. The availability of new sequencing technologies provides new choices for sequencing of gene space of the wheat genome. The applications of flow-sorted chromosomes in wheat genome studies present some examples to analyze the complex genomes of cereals.
Effect of Environmental Changes on Phytic Acid Content of Wheat (Triticum aestivum)  [PDF]
Talat Mahmood,Tabassum Hameed,Nouman Rashid Siddiqui,Amir Mumtaz
Pakistan Journal of Nutrition , 2010,
Abstract: Wheat (Triticum aestivum) is one of the most important food grain crops in all South Asian countries especially in India and Pakistan. These countries have diversifying soil and climatic conditions inserting measurable effect on nutritional as well as anti-nutritional parameters of wheat. Wheat varieties included in this study are collected from different agro-ecological zones of Pakistan. Myoinositol hexa-phosphate (phytic acid) one of major anti-nutritional factors wheat. Phytic acid of collected samples was determined to facilitate the crop breeders and agronomists, so that they would also consider this factor while conducting research works. It was observed that wheat varieties showed different levels of phytic acid at different locations. At one location (Islamabad), a variety (Pari-73) showed the highest value of Phytic acid (1.343%) and at other location (Faisalabad), same variety the showed lowest phytic acid (0.74%). This maximum variability (44%) also indicated that there was significant effect of change in location on phytic acid contents of wheat varieties. It is mainly due to presence of available phosphorus reserves in soil as phytate has direct relation to soil phosphorus.
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