Effect of gamma radiation on wheat plant growth due to impact on gas exchange characteristics and mineral nutrient uptake and utilization

The experiment was conducted to determine the effect of gamma radiation on plant growth and development, flag leaf gas exchange characteristics such as net photosynthetic rate (P _N), stomatal conductance (g _s), and transpiration rate (E) and activity of key carbon and nitrogen assimilating enzymes like Rubisco, starch synthase (SS) and nitrate reductase (NR) in field grown wheat. Grains of cultivar PBW-343 were exposed to a ⁶⁰Co (Cobalt-60) gamma source at a dose range from 0 to 500 Gy (Gray). Gas exchange characteristics of flag leaf were measured using Infrared Gas Analyzer (IRGA), while mineral nutrients were analyzed spectrophotometrically. Our results show that an irradiation treatment, in general, caused an improvement in plant growth and yield characteristics such as shoot and root mass, root length and surface area, leaf area and chlorophyll SPAD index, tiller number and grain yield. However, irradiation exceeding 5 Gy reduced the magnitude of radiation advantage for most of the investigated physiological and biochemical traits. No germination was recorded at 500 Gy irradiation dose. A dose-dependant increase in shoot Fe in radiated plants up to 25 Gy reflected its higher plant root to shoot translocation which may yield micronutrient rich grains. At higher dose of 100 Gy, there was a drastic reduction in flag leaf membrane stability index (MSI), photosynthesis, Rubisco, NR, and nutrients like K, P, Mg, Fe, and Zn. Starch synthase enzyme activity was unaffected by gamma irradiation indicating that the negative effect of high dose (100 Gy) on the grain yield were caused by the adverse effect of radiation on the gas exchange attributes particularly photosynthesis, carbon, and nitrogen assimilation efficiency and the plant uptake of mineral nutrients. The study concludes that gamma radiation at a low dose (25 Gy or lower) stimulates, while a high dose (100 Gy and above) inhibits plant growth and development of wheat. The adverse effect at 100 Gy and beyond could be attributed to the poor carbon and nitrogen assimilation efficiency and the plant uptake of mineral nutrients, all of which are the ultimate determinant of plant health.     

Siderophore as a Potential Plant Growth-Promoting Agent Produced by Pseudomonas aeruginosa JAS-25

Siderophores scavenges Fe⁺³ from the vicinity of the roots of plants, and thus limit the amount of iron required for the growth of pathogens such as Fusarium oxysporum, Pythium ultimum, and Fusarium udum, which cause wilt and root rot disease in crops. The ability of Pseudomonas to grow and to produce siderophore depends upon the iron content, pH, and temperature. Maximum yield of siderophore of 130 μM was observed at pH 7.0?±?0.2 and temperature of 30 °C at 30 h. The threshold level of iron was 50 μM, which increases up to 150 μM, favoring growth but drastically affecting the production of siderophore by Pseudomonas aeruginosa JAS-25. The seeds of agricultural crops like Cicer arietinum (chick pea), Cajanus cajan (pigeon pea), and Arachis hypogaea (ground nut) were treated with P. aeruginosa JAS-25, which enhanced the seed germination, root length, shoot length, and dry weight of chick pea, pigeon pea, and ground nut plants under pot studies. The efficient growth of the plants was not only due to the biocontrol activity of the siderophore produced by P. aeruginosa JAS-25 but also may be by the production of indole acetic acid (IAA), which influences the growth of the plants as phytohormones.     

Isolation of herbicidal compounds,quercetin and β-caryophyllene,from Digera muricata

Synthetic herbicides are available to control weeds but these herbicides have many concerns. Eco-friendly herbicides obtained from plants is a better alternative to synthetic ones. Despite that the herbicidal activity of Digera muricata extracts have been reported but there are no studies regarding the isolation and identification of herbicidal compounds from D. muricata. Herein, we are reporting the identification of two herbicidal compounds from chloroform extract obtained from D. muricata. The chloroform extract was initially tested on the germination and early growth of two weeds; Avena fatua and Melilotus indicus as well as wheat where a significant decline in % age germination and growth of both weeds was observed. Among the 8 different fractions obtained using different chromatographic techniques, fractions 2 and 7 were found to be phytotoxic to both test weeds. The herbicidal efficacy was tested at 200, 150, 100, 50, 25 μg/ml. These two fractions were further purified on Reversed Phase High Pressure Liquid Chromatography (RP-HPLC). Fraction 2 yielded 3 sub-fractions (2A, 2B & 2C), while fraction 7 yielded 2 sub-fractions (7A, 7B). Fraction 2B caused 43%, 53%, and 57% decline in seed germination, shoot dry weight, and root dry weight of A. fatua, while these values against M. indicus were 50%, 81% and 84%, respectively. Fraction 7A caused 25%, 36%, and 42% decline in seed germination, shoot dry weight, and root dry weight of A. fatua, while these values against M. indicus were 35%, 62% and 69%, respectively, at 200 μg/ml conc. Cyanazine caused 61% and 50% reduction in seed germination of A. fatua and M. indicus, respectively. The herbicidal effects of these two fractions were found nonsignificant against wheat. Fourier Transform Infrared Spectroscopy (FT-IR), elemental analysis (C,H) and Nuclear Magnetic Resonanace (NMR) analyses of these two fractions depicted the presence of quercetin (Fraction 2B) and β-caryophyllene (Fraction 7A). In post emergence bioassays, the isolated compounds caused significant decrease in the biomass of both weeds. Plasma membrane integrity assays revealed electrolyte leakage in treated leaf discs of both weeds. It was concluded that quercetin and β-caryophyllene isolated from D. muricata exhibited toxicity towards both test weeds without harming wheat.     

Effects of Ion Beams Pretreatment on Damage of UV-B Radiation on Seedlings of Winter Wheat (Triticum aestivum L.)

The seeds of winter wheat were pretreated with three different doses of low-energy N⁺ beams, and its seedlings were subjected to UV-B irradiation (10.08?kJ?m^?2?day^?1) at three-leaves stage. The growth characteristic of seeds, the oxidative damage to membrane system induced by UV-B radiation, and the alleviating effects of N⁺ beams pretreatment to radiation damage were investigated. The results showed that the germination rate and seedling rate, respectively, increased 14.09?±?1.03 and 13.91?±?1.21?% compared with control (CK) at the dose of 4.0?×?10¹⁶ ions/cm². When seedlings were exposed to UV-B radiation, the pretreatment method under the dose of 4.0?×?10¹⁶ ions/cm² made the activity of peroxidase and superoxide dismutase increasing, the content of chlorophyll enhancing, but the content of malondialdehyde reducing significantly compared with that of the single UV-B radiation. Whereas, the activity of catalase irradiated by UV-B improved notably under the pretreatment dose of 8.0?×?10¹⁶ ions/cm². In addition, after being irradiated with UV-B, the content of soluble protein and glutathione whose seeds were pretreated by the dose of 6.0?×?10¹⁶ ions/cm² were higher than that of the single UV-B radiation. It was suggested that the suitable dose of low-energy ion beams pretreatment to wheat seeds could change its physiological characteristics at seedlings stage to alleviate the damage effects from UV-B radiation.     

Effect of Cold Atmospheric Pressure Plasma on the Wheat Seedlings Vigor and on the Inactivation of Microorganisms on the Seeds Surface

Effects of a cold atmospheric pressure plasma (CAPP) treatment on the germination, production of biomass, vigor of seedlings, uptake of water of wheat seeds (Triticum aestivum L. cv. Eva) were investigated. The CAPP treatment influence on the inactivation of microorganisms occurring on the surface of wheat seeds was investigated also. The so-called Diffuse Coplanar Surface Barrier Discharge generating a cold plasma in ambient air with high power volume density of some 100 W/cm³ was used for the treatment of seeds at exposure times in the range of 10–600 s. The optical emission spectroscopy and the electrical measurements were used for estimation of CAPP parameters. The obtained results indicate that the germination rate, dry weight and vigor of seedlings significantly increased for plasma treatment from 20 to 50 s. The plasma treatment of seeds led to an extensive increase in wettability and faster germination comparing with the untreated seeds. The growth inhibition effect of CAPP on the surface microflora of wheat seeds increased with the increase of the treatment time. The efficiency of the treatment of wheat seeds artificially contaminated with pure cultures of filamentous fungi decreased in the following order: Fusarium nivale > F. culmorum > Trichothecium roseum > Aspergillus flavus > A. clavatus.     

The effects of differentiated water supply after anthesis and nitrogen fertilization on δ15N of wheat grain

The δ¹⁵N signature of plants integrates various processes in soil and plant. In this study, the effect of different water regimes applied during the period of grain growth of winter wheat on grain δ¹⁵N was examined in a 4‐year field experiment. The treatments comprised water shortage (S), an ample water supply (W), and rain‐fed crop (R). Zero fertilization (N0) and 200 kg N.ha^?1 in mineral fertilizer (N1) treatments were studied. The grain ¹⁵N was determined during grain growth and at maturity. The water regime, nitrogen application and year had a significant effect on mature grain δ¹⁵N (p < 0.001). Water and nitrogen explained 54.6% of the variability of δ¹⁵N in the experiment, the year accounted for 10.7% and the interactions for another 19.6% of the total variability. The analysis of non‐mature grain δ¹⁵N showed significant effects of N and year but not of water. Nitrogen fertilization reduced the δ¹⁵N of mature grain in years by 0.7–6.3‰ in comparison with N0 plants; the reduction was more pronounced under stress (average reduction by 4.1‰) than under rain‐fed (2.4‰) and ample water supply (2.2‰). Water stress decreased the grain δ¹⁵N in fertilized wheat, by 0.1–2.1‰ and 0.6–3.6‰ in experimental years, on average by 1.30‰ and 1.79‰ in comparison with the R and W water supply, respectively. The effect of water supply was not significant in non‐fertilized wheat. A significant negative linear relationship between grain N concentration and δ¹⁵N in maturity or during the grain growth (R² = 0.83, R² = 0.76, respectively) was found. The observed sources of grain δ¹⁵N variability should be taken into consideration when analyzing and interpreting the data on the δ¹⁵N signature of plant material from field conditions. Copyright © 2010 John Wiley & Sons, Ltd.     

Elemental analysis of fertilizers using X-ray fluorescence and their impact on alpha radioactivity of plants

The fertilizers used for plantation contain different elements including some natural radionuclides with their daughter decay products. The radiological impact of the use of fertilizers may be due to internal irradiation of the lung by the alpha particles, short lived radon-thoron progeny and the external irradiation of the body by gamma ray emitted from the radionuclides. The aim of this study was to estimate the enhanced alpha radioactivity in different parts of plants due to fertilizers and to measure the concentration of different elements present in the fertilizers. A control study was carried out on round gourd plants using different fertilizers. Fertilizers were added to the soil just before the plantation of seeds in the pots. For the measurement of alpha track densities in different parts of plants we used α-sensitive LR-115 type II plastic track detectors. The alpha-track density (T cm^?2 days^?1) was measured in leaves of plants at different interval of time. The variation in alpha track densities was also observed in root, stem leaf and grain parts of the plants. In case of the plants grown using some phosphate fertilizers the alpha radioactivity was found to be more compared with others. A positive correlation between alpha track densities and mass exhalation rates of radon from different fertilizers has been observed. The concentration of major elements (Al, Si, P, S, Cl, K) along with other elements present in fertilizer samples was measured by X-ray fluorescence analysis.     

Role of Bacillus cereus in Improving the Growth and Phytoextractability of Brassica nigra (L.) K. Koch in Chromium Contaminated Soil

Plant growth-promoting rhizobacteria (PGPR) mediate heavy metal tolerance and improve phytoextraction potential in plants. The present research was conducted to find the potential of bacterial strains in improving the growth and phytoextraction abilities of Brassica nigra (L.) K. Koch. in chromium contaminated soil. In this study, a total of 15 bacterial strains were isolated from heavy metal polluted soil and were screened for their heavy metal tolerance and plant growth promotion potential. The most efficient strain was identified by 16S rRNA gene sequencing and was identified as Bacillus cereus. The isolate also showed the potential to solubilize phosphate and synthesize siderophore, phytohormones (indole acetic acid, cytokinin, and abscisic acid), and osmolyte (proline and sugar) in chromium (Cr⁺³) supplemented medium. The results of the present study showed that chromium stress has negative effects on seed germination and plant growth in B. nigra while inoculation of B. cereus improved plant growth and reduced chromium toxicity. The increase in seed germination percentage, shoot length, and root length was 28.07%, 35.86%, 19.11% while the fresh and dry biomass of the plant increased by 48.00% and 62.16%, respectively, as compared to the uninoculated/control plants. The photosynthetic pigments were also improved by bacterial inoculation as compared to untreated stress-exposed plants, i.e., increase in chlorophyll a, chlorophyll b, chlorophyll a + b, and carotenoid was d 25.94%, 10.65%, 20.35%, and 44.30%, respectively. Bacterial inoculation also resulted in osmotic adjustment (proline 8.76% and sugar 28.71%) and maintained the membrane stability (51.39%) which was also indicated by reduced malondialdehyde content (59.53% decrease). The antioxidant enzyme activities were also improved to 35.90% (superoxide dismutase), 59.61% (peroxide), and 33.33% (catalase) in inoculated stress-exposed plants as compared to the control plants. B. cereus inoculation also improved the uptake, bioaccumulation, and translocation of Cr in the plant. Data showed that B. cereus also increased Cr content in the root (2.71-fold) and shoot (4.01-fold), its bioaccumulation (2.71-fold in root and 4.03-fold in the shoot) and translocation (40%) was also high in B. nigra. The data revealed that B. cereus is a multifarious PGPR that efficiently tolerates heavy metal ions (Cr⁺³) and it can be used to enhance the growth and phytoextraction potential of B. nigra in heavy metal contaminated soil.     

Increased Availability of Tryptophan in 5-Methyltryptophan-Tolerant Shoots of Catharanthus roseus and Their Postharvest in vivo Elicitation Induces Enhanced Vindoline Production

Ten 5-methyltryprophan (5-MT)-resistant multiple shoot culture lines in three genotypes of Catharanthus roseus were selected in vitro. The variant shoot lines displayed a differential threshold tolerance limit against the analogue stress, ranged from 20 to 70?mg/l 5-MT in the medium. The lines tolerant to 40?mg/l 5-MT stress were most stable and fast proliferating. All the selected lines in the presence of 5-MT stress recorded increased level of tryptophan in their free amino acid pool. Highest tryptophan accumulation occurred in lines P40, P30, D40, and N40 (i.e., 296.5, 241.0, 200.6, and 202.0???g/g dry wt., respectively). A concomitant increase in the total alkaloid content (2.3?C3.8?% dry wt.) under the analogue stress was also noticed in these lines when compared to 1.0?C1.58?% dry wt. in the respective wild-type shoot maintained on a stress-free medium. The HPLC analysis of the alkaloid extracts of the 5-MT-tolerant lines grown under analogue stress also revealed vindoline as a major constituent with maximum accumulation in lines N40, N30, D30, D40, and P40 (0.046, 0.032, 0.034, and 0.022?% dry wt., respectively). The rooted shoots of 5-MT-tolerant lines were successfully acclimatized under glasshouse environment wherein they grew normally and set seeds. Flowering twigs or leaves excised from 1-year-old glasshouse-grown plants of 5-MT variant lines upon postharvest in vivo elicitation with 30?mg/l 5-MT or 5.0?mg/l tryptophan registered an eight-to-tenfold increment in their vindoline content within 24?C48?h.     

13C/12C isotope labeling to study carbon partitioning and dark respiration in cereals subjected to water stress

Despite the relevance of carbon (C) loss through respiration processes (with its consequent effect on the lower C availability for grain filling), little attention has been given to this topic. Literature data concerning the role of respiration in cereals are scarce and these have been produced using indirect methods based on gas‐exchange estimations. We have developed a new method based on the capture of respired CO₂ samples and their analysis by gas chromatography‐combustion‐isotope ratio mass spectrometry (GC‐C‐IRMS). In order to analyse the main processes involved in the C balance during grain filling (photosynthesis, respiration, allocation and partitioning) the ambient isotopic ¹³C/¹²C composition (δ¹³C) of the growth chamber was modified during this period (δ¹³C ca. ?12.8 ± 0.3‰ to ca. ?20.0 ± 0.2‰). The physiological performance, together with the C allocation on total organic matter (TOM) and respiration of wheat (Triticum aestivum L., var. Califa sur) and two hybrids, tritordeum (X Tritordeum Asch. & Graebn line HT 621) and triticale (X Triticosecale Wittmack var. Imperioso), were compared during post‐anthesis water stress. In spite of the larger ear DM/total ratio, especially under drought conditions, the grain filling of triticale and wheat was mainly carried out with pre‐anthesis C, while the majority of C assimilated during post‐anthesis was invested in respiration processes. In the case of wheat and tritordeum, the C balance data suggested a reallocation during grain filling of photoassimilates stored prior to anthesis from shoot to ear. Furthermore, the lower percentage of labeled C on respired CO₂ of droughted tritordeum plants, together with the lower plant biomass, explained the fact that those plants had more C available for grain filling. Copyright © 2009 John Wiley & Sons, Ltd.     

Assessment of annual effective dose from natural radioactivity intake through wheat grain produced in Faisalabad,Pakistan

Wheat is staple food of the people of Pakistan. Phosphate fertilizers, used to increase the yield of wheat, enhance the natural radioactivity in the agricultural fields from where radionuclides are transferred to wheat grain. A study was, therefore, carried out to investigate the uptake of radioactivity by wheat grain and to determine radiation doses received by human beings from the intake of foodstuffs made of wheat grain. Wheat was grown in a highly fertilized agricultural research farm at the Nuclear Institute of Agriculture and Biology (NIAB), Faisalabad, Pakistan. The activity concentration of ⁴⁰K, ²²⁶Ra and ²³²Th was measured in soil, single superphosphate (SSP) fertilizer, and wheat grain using an HPGe-based gamma-ray spectrometer. Soil to wheat grain transfer factors determined for ⁴⁰K, ²²⁶Ra and ²³²Th were 0.118 ± 0.021, 0.022 ± 0.004 and 0.036 ± 0.007, respectively, and the annual effective dose received by an adult person from the intake of wheat products was estimated to be 217 μSv.     

Plant Regeneration Through Callus Organogenesis and True-to-Type Conformity of Plants by RAPD Analysis in Desmodium gangeticum (Linn.) DC.

An efficient plant regeneration protocol was established for an endangered ethnomedicinal plant Desmodium gangeticum (Linn.) DC. Morphogenic calli were produced from 96 % of the cultures comprising the immature leaf explants on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (4.0 mg?l^?1) in combination with 6-benzylaminopurine (BA; 0.8 mg?l^?1). For callus regeneration, various concentrations of BA (1.0–5.0 mg?l^?1) or thidiazuron (TDZ; 1.0–5.0 mg?l^?1) alone or in combination with indole-3-acetic acid (IAA; 0.2–1.0 mg?l^?1) were used. Highest response of shoot regeneration was observed on MS medium fortified with TDZ (4.0 mg?l^?1) and IAA (0.5 mg?l^?1) combination. Here, 100 % cultures responded with an average number of 22.3 shoots per gram calli. Inclusion of indole-3-butyric acid in half MS medium favored rooting of recovered shoots. Out of 45 rooted plants transferred to soil, 40 survived. Total DNA was extracted from the leaves of the acclimatized plants of D. gangeticum. Analysis of random amplified polymorphic DNA using 13 arbitrary decanucleotide primers showed the genetic homogeneity in all the ten plants regenerated from callus with parental plant, suggesting that shoot regeneration from callus could be used for the true-to-type multiplication of this plant.     

Effects of long‐term exposure to elevated CO2 conditions in slow‐growing plants using a 12C‐enriched CO2‐labelling technique

Despite their relevancy, long‐term studies analyzing elevated CO₂ effect in plant production and carbon (C) management on slow‐growing plants are scarce. A special chamber was designed to perform whole‐plant above‐ground gas‐exchange measurements in two slow‐growing plants (Chamaerops humilis and Cycas revoluta) exposed to ambient (ca. 400 µmol mol^?1) and elevated (ca. 800 µmol mol^?1) CO₂ conditions over a long‐term period (20 months). The ambient isotopic ¹³C/¹²C composition (δ¹³C) of plants exposed to elevated CO₂ conditions was modified (from ca. ?12.8‰ to ca. ?19.2‰) in order to study carbon allocation in leaf, shoot and root tissues. Elevated CO₂ increased plant growth by ca. 45% and 60% in Chamaerops and Cycas, respectively. The whole‐plant above‐ground gas‐exchange determinations revealed that, in the case of Chamaerops, elevated CO₂ decreased the photosynthetic activity (determined on leaf area basis) as a consequence of the limited ability to increase C sink strength. On the other hand, the larger C sink strength (reflected by their larger CO₂ stimulatory effect on dry mass) in Cycas plants exposed to elevated CO₂ enabled the enhancement of their photosynthetic capacity. The δ¹³C values determined in the different plant tissues (leaf, shoot and root) suggest that Cycas plants grown under elevated CO₂ had a larger ability to export the excess leaf C, probably to the main root. The results obtained highlighted the different C management strategies of both plants and offered relevant information about the potential response of two slow‐growing plants under global climate change conditions. Copyright © 2008 John Wiley & Sons, Ltd.     

Effect of low dose gamma irradiation on plant and grain nutrition of wheat

We recently reported the use of low dose gamma irradiation to improve plant vigor, grain development and yield attributes of wheat (Singh and Datta, 2010). Further, we report here the results of a field experiment conducted to assess the effect of gamma irradiation at 0, 0.01, 0.03, 0.05, 0.07 and 0.1 kGy on flag leaf area, stomatal conductance, transpiration and photosynthetic rate and plant and grain nutritional quality. Gamma irradiation improved plant nutrition but did not improve the nutritional quality of grains particularly relating to micronutrients. Grain carotene, a precursor for vitamin A, was higher in irradiated grains. Low grain micronutrients seem to be caused by a limitation in the source to sink nutrient translocation rather than in the nutrient uptake capacity of the plant root.     

In Vitro Propagation,Encapsulation, and Genetic Fidelity Analysis of Terminalia arjuna: a Cardioprotective Medicinal Tree

The present study described an improved and reproducible in vitro regeneration system for Terminalia arjuna using nodal segment explants obtained from a mature plant. Shoot tips excised from in vitro proliferated shoots were encapsulated in 3 % sodium alginate and 100 mM CaCl₂?2H₂O for the development of synthetic seeds which may be applicable in short-term storage and germplasm exchange of elite genotype. Shoot multiplication was significantly influenced by a number of factors, namely types and concentrations of plant growth regulators, medium composition, repeated transfer of mother explants, subculturing of in vitro regenerated shoot clumps, agar concentrations, and temperature. Maximum numbers of shoots (16.50?±?3.67) were observed on modified Murashige and Skoog (MMS) medium containing 0.5 mg l^?1 of benzylaminopurine (BAP) and 0.1 mg l^?1 of naphthalene acetic acid (NAA). To shortening the regeneration pathway, rooting of micropropagated shoots under in vitro condition was excluded and an experiment on ex vitro rooting was conducted and it was observed that the highest percentage of shoots rooted ex vitro when treated with indole-3-butyric acid (IBA, 250 mg l^?1)?+?2-naphthoxy acetic acid (NOA, 250 mg l^?1) for 5 min. The well-developed ex vitro rooted shoots were acclimatized successfully in soilrite under greenhouse conditions with 80 % survival of plants. Randomly amplified polymorphic DNA (RAPD) analysis confirmed that all the regenerated plants were genetically identical to the mother plant, suggesting the absence of detectable genetic variation in the regenerated plantlets. To the best of our knowledge, this is the first report on synthetic seed production as well as ex vitro rooting and genetic fidelity assessment of micropropagated shoots of T. arjuna.     

An Improved Micropropagation of Arnebia hispidissima (Lehm.) DC. and Assessment of Genetic Fidelity of Micropropagated Plants Using DNA-Based Molecular Markers

An efficient and improved in vitro propagation method has been developed for Arnebia hispidissima, a medicinally and pharmaceutically important plant species of arid and semiarid regions. Nodal segments (3–4 cm) with two to three nodes obtained from field grown plants were used as explants for shoot proliferation. Murashige and Skoog’s (MS) medium supplemented with cytokinins with or without indole-3-acetic acid (IAA) or naphthalene acetic acid was used for shoot multiplication. Out of different PGRs combinations, MS medium containing 0.5 mg l^?1 6-benzylaminopurine and 0.1 mg l^?1 IAA was optimal for shoot multiplication. On this medium, explants produced the highest number of shoots (47.50?±?0.38). About 90 % of shoots rooted ex vitro on sterile soilrite under the greenhouse condition when the base (2–4 mm) of shoots was treated with 300 mg l^?1 of indole-3-butyric acid for 5 min. The plantlets were hardened successfully in the greenhouse with 85–90 % survival rate. Random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were employed to assess the genetic stability of in vitro-regenerated plants of A. hispidissima. Out of 40 (25 RAPD and 15 ISSR) primers screened, 15 RAPD and 7 ISSR primers produced a total number of 111 (77 RAPD and 34 ISSR) reproducible amplicons. The amplified products were monomorphic across all the micropropagated plants and were similar to the mother plant. To the best of our knowledge, it is the first report on the assessment of the genetic fidelity in micropropagated plants of A. hispidissima.     

Nitrogen assay in winter wheat by short-time instrumental photon activation analysis and its comparison with the Kjeldahl method

The nitrogen content in winter wheat from various crops grown organically or conventionally was determined by instrumental photon activation analysis. The method utilizes measurement of the annihilation gamma line at 511 keV from the short-lived photoactivation product ¹³N, corrected for interference contributions from other positron emitting nuclides. Results compared well to those obtained by the Kjeldahl method. A positive impact of conventional agriculture on higher crude protein content in grain was found. Analysis of whole kernels and their germination and growth after irradiation were also tested.

     

Voltammetric Determination of Zinc,Copper, and Selenium in Selected Raw Plant Material

The objective of this work was to determine zinc, copper, and selenium content in selected plant raw materials used as pharmaceuticals, foodstuffs, or spices. The study included: Chamomillae anthodium, Anisi fructus, Menthae piperitae folium, Equiseti herba, Urticae folium, quinoa seeds (Chenopodium quinoa), amaranth seeds (Amaranthus cruentus), clove (Syzygium aromaticum), and oregano (Origanum vulgare). Stripping voltammetry with differential pulse step was used for zinc, copper, and selenium determination after microwave digestion procedure for organic matrix decomposition. Obtained results showed that proposed methods were suitable in determination of selenium, copper, and zinc. Selenium content varied from 11.6 µgkg^?1 of dry weight of oregano up to 1031.2 µg kg^?1 for amaranth. Zinc content ranged from 11.1 to 42.1 mgkg^?1 and copper content was between 0.7 and 12.0 mg kg^?1. The proposed method was successfully applied and validated by studying the certified reference material (INCT-MPH-2, bovine liver BCR-185), with recovery 94%–102%; 92%–97%; and 97%–108% for copper, zinc, and selenium, respectively.     

Optimization of Elicitation Conditions with Methyl Jasmonate and Salicylic Acid to Improve the Productivity of Withanolides in the Adventitious Root Culture of Withania somnifera (L.) Dunal

Adventitious root cultures derived from leaf derived callus of Withania somnifera (L.) Dunal were treated with methyl jasmonate and salicylic acid independently. Biomass accumulation, culture age, elicitation period, and culture duration were optimized for higher withanolides production in the two best-responding varieties collected from Kolli hills (Eastern Ghats) and Cumbum (Western Ghats) of Tamil Nadu, India. Between the two elicitors, salicylic acid (SA) improved the production of major withanolides (withanolide A, withanolide B, withaferin A, and withanone) as well as minor constituents (12-deoxy withastramonolide, withanoside V, and withanoside IV) in the Kolli hills variety. Treatment of root biomass (11.70?g FW) on 30-day-old adventitious root cultures with 150???M SA for 4?h elicitor exposure period resulted in the production of 64.65?mg?g^?l dry weight (DW) withanolide A (48-fold), 33.74?mg?g^?l DW withanolide B (29-fold), 17.47?mg?g^?l DW withaferin A (20-fold), 42.88?mg?g^?l DW withanone (37-fold), 5.34?mg?g^?l DW 12-deoxy withastramonolide (nine fold), 7.23?mg?g^?l DW withanoside V (seven fold), and 9.45?mg?g^?l DW withanoside IV (nine fold) after 10?days of elicitation (40th day of culture) when compared to untreated cultures. This is the first report on the use of elicitation strategy on the significant improvement in withanolides production in the adventitious root cultures of W. somnifera.