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Sample records for water-stressed barley leaves

  1. Proline accumulation in water-stressed barley leaves in relation to translocation and the nitrogen budget

    International Nuclear Information System (INIS)

    Tully, R.E.; Hanson, A.D.; Nelsen, C.E.

    1979-01-01

    Mobilization of N from leaves of barley (Hordeum vulgare L.) during water stress, and the role of proline as a mobilized species, were examined in plants at the three-leaf stage. The plants responded to water stress by withdrawing about 25% of the total reduced N from the leaf blades via phloem translocation. Most of this N loss was during the first 2 days while translocation of 14 C-photosynthate out of the stressed blade still remained active. Free proline accumulation in the blade was initially slow, and became more rapid during the 2nd day of stress. Although a major free amino acid, proline accounted for only about 5% of the total N(soluble + insoluble) retained in severely stressed blades. When the translocation pathway in water-stressed leaves was interrupted just below the blade by a heat girdle, a cold jacket, or by blade excision, N loss from the blade was prevented and proline began to accumulate rapidly on 1st day of stress. Little free proline accumulated in the blades until after the ability to translocate was lost. Proline was, however, probably not a major species of N translocated during stress, because proline N accumulation in heat-girdled stressed leaves was five times slower than the rate of total N export from intact blades

  2. AFLP marker linked to water-stress-tolerant bulks in barley (Hordeum vulgare L.

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    A. Altinkut

    2003-01-01

    Full Text Available The amplified fragment length polymorphism (AFLP assay is an efficient method for the identification of molecular markers, useful in the improvement of numerous crop species. Bulked Segregant Analysis (BSA was used to identify AFLP markers associated with water-stress tolerance in barley, as this would permit rapid selection of water-stress tolerant genotypes in breeding programs. AFLP markers linked to water-stress tolerance was identified in two DNA pools (tolerant and sensitive, which were established using selected F2 individuals resulting from a cross between water-stress-tolerant and sensitive barley parental genotypes, based on their paraquat (PQ tolerance, leaf size, and relative water content (RWC. All these three traits were previously shown to be associated with water-stress tolerance in segregating F2 progeny of the barley cross used in a previous study. AFLP analysis was then performed on these DNA pools, using 40 primer pairs to detect AFLP fragments that are present/absent, respectively, in the two pools and their parental lines. One separate AFLP fragment, which was present in the tolerant parent and in the tolerant bulk, but absent in the sensitive parent and in the sensitive bulk, was identified. Polymorphism of the AFLP marker was tested among tolerant and sensitive F2 individuals. The presence of this marker that is associated with water-stress tolerance will greatly enhance selection for paraquat and water-stress tolerant genotypes in future breeding programs.

  3. Responses of growth and primary metabolism of water-stressed barley roots to rehydration

    Science.gov (United States)

    Barley seedlings [Hordeum vulgare L. Brant] were grown in pots in controlled environment chambers and drought treatments were imposed 11 days after sowing. Soil water content decreased from 92% to 10% after an additional 14 days of water stress. Shoot and root growth ceased after 4 and 9 days of wat...

  4. Variable Levels of Tolerance to Water Stress (Drought and Associated Biochemical Markers in Tunisian Barley Landraces

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    Sameh Dbira

    2018-03-01

    Full Text Available Due to its high tolerance to abiotic stress, barley (Hordeum vulgare is cultivated in many arid areas of the world. In the present study, we evaluate the tolerance to water stress (drought in nine accessions of “Ardhaoui” barley landraces from different regions of Tunisia. The genetic diversity of the accessions is evaluated with six SSR markers. Seedlings from the nine accessions are subjected to water stress by completely stopping irrigation for three weeks. A high genetic diversity is detected among the nine accessions, with no relationships between genetic distance and geographical or ecogeographical zone. The analysis of growth parameters and biochemical markers in the water stress-treated plants in comparison to their respective controls indicated great variability among the studied accessions. Accession 2, from El May Island, displayed high tolerance to drought. Increased amounts of proline in water-stressed plants could not be correlated with a better response to drought, as the most tolerant accessions contained lower levels of this osmolyte. A good correlation was established between the reduction of growth and degradation of chlorophylls and increased levels of malondialdehyde and total phenolics. These biochemical markers may be useful for identifying drought tolerant materials in barley.

  5. Abscisic acid biosynthesis in water-stressed leaves

    International Nuclear Information System (INIS)

    Li, Yi.

    1989-01-01

    Although abscisic acid (ABA) was discovered 30 years ago, very little is known about its biosynthetic pathway in higher plants. Two hypotheses have been proposed: (i) a direct pathway involving only C-15 intermediates like farnesyl pyrophosphate, (ii) an indirect pathway involving C-40 intermediates like the xanthophylls. When 14 CO 2 was fed into greened bean plants, the 14 C specific activity of ABA was always lower than those in xanthophylls, such as violaxanthin and lutein, regardless of 12 CO 2 chase periods. The ABA accumulation in green leaves was not affected by fluridone when plants were stressed once, but the 14 C incorporation into ABA was inhibited to the same extent as those of xanthophylls. The incorporation of 18 O into the ABA ring when violaxanthin was labeled by 18 O in vivo via the violaxanthin cycle indicates that at least a portion of ABA was derived from 18 O-labeled violaxanthin during water stress

  6. Abscisic acid biosynthesis in water-stressed leaves

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yi.

    1989-01-01

    Although abscisic acid (ABA) was discovered 30 years ago, very little is known about its biosynthetic pathway in higher plants. Two hypotheses have been proposed: (i) a direct pathway involving only C-15 intermediates like farnesyl pyrophosphate, (ii) an indirect pathway involving C-40 intermediates like the xanthophylls. When {sup 14}CO{sub 2} was fed into greened bean plants, the {sup 14}C specific activity of ABA was always lower than those in xanthophylls, such as violaxanthin and lutein, regardless of {sup 12}CO{sub 2} chase periods. The ABA accumulation in green leaves was not affected by fluridone when plants were stressed once, but the {sup 14}C incorporation into ABA was inhibited to the same extent as those of xanthophylls. The incorporation of {sup 18}O into the ABA ring when violaxanthin was labeled by {sup 18}O in vivo via the violaxanthin cycle indicates that at least a portion of ABA was derived from {sup 18}O-labeled violaxanthin during water stress.

  7. REDUCTION OF HERBICIDE AND WATER STRESS IN SPRING BARLEY BY REGULATORS OF POLYAMINE BIOSYNTHESIS

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    Pavol Trebichalský

    2014-02-01

    Full Text Available The experiment was carried out under artificial light of fluorescent lamps starting with 60 % full water capacity which was afterwards decreased on 40 % and finally the plants of barley were not watered. 30 plants of this cereal after plant emergence were thinned on 22 pieces. Experiment was treated by triazine herbicide, as well as its mixtures of regulators of polyamine synthesis: γ-aminobutyric acid, 1.3-propylenediamine dihydrochloride and salicyl acid. Solo application of triazine herbicide during water stress had negative balance on formation of root and above ground biomass. Addition of regulators of polyamine synthesis had positive effects on mentioned parameters, but not in comparison to control variant. These stress factors were eliminated most significantly only the application of GABA (100 g.ha-1 in mixture with herbicide.

  8. Metabolite Profiling of Barley Grains Subjected to Water Stress: To Explain the Genotypic Difference in Drought-Induced Impacts on Malting Quality

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    Xiaojian Wu

    2017-09-01

    Full Text Available Grain weight and protein content will be reduced and increased, respectively, when barley is subjected to water stress after anthesis, consequently deteriorating the malt quality. However, such adverse impact of water stress differs greatly among barley genotypes. In this study, two Tibetan wild barley accessions and two cultivated varieties differing in water stress tolerance were used to investigate the genotypic difference in metabolic profiles during grain-filling stage under drought condition. Totally, 71 differently accumulated metabolites were identified, including organic acids, amino acids/amines, and sugars/sugar alcohols. Their relative contents were significantly affected by water stress for all genotypes and differed distinctly between the wild and cultivated barleys. The principal component analysis of metabolites indicated that the Tibetan wild barley XZ147 possessed a unique response to water stress. When subjected to water stress, the wild barley XZ147 showed the most increase of β-amylase activity among the four genotypes, as a result of its higher lysine content, less indole-3-acetic acid (IAA biosynthesis, more stable H2O2 homeostasis, and more up-regulation of BMY1 gene. On the other hand, XZ147 had the most reduction of β-glucan content under water stress than the other genotypes, which could be explained by the faster grain filling process and the less expression of β-glucan synthase gene GSL7. All these results indicated a great potential for XZ147 in barley breeding for improving water stress tolerance.

  9. Dry matter yield, carbon isotope discrimination and nitrogen uptake in silicon and/ or potassium fed chickpea and barley plants grown under water and non-water stress conditions

    International Nuclear Information System (INIS)

    Kurd Ali, F.; Al-Chammaa, M.; Mouasess, A.

    2012-09-01

    A pot experiment was conducted to study the effects of silicon (Si) and/or potassium (K) on dry matter yield, nitrogen uptake and carbon isotope discrimination Δ 13 C in water stressed (FC1) and well watered (FC2) chickpea plants using 15 N and 13 C isotopes. Three fertilizer rates of Si (Si 5 0, Si 1 00 and Si 2 00) and one fertilizer rate of K were used. The results showed that: In chickpeas, it was found, for most of the growth parameters, that Si either alone or in combination with K was more effective to alleviate water stress than K alone. Increasing soil water level from FC1 to FC2 often had a positive impact on values of most studied parameters. The Si 1 00K + (FC1) and Si 5 0K + (FC2) treatments gave high enough amounts of N 2 -fixation, higher dry matter production and greater nitrogen yield. The percent increments of total N 2 -fixed in the above mentioned treatments were 51 and 47% over their controls, respectively. On the other hand, increasing leaves dry matter in response to the solely added Si (Si 5 0K - and Si 1 00K - ) is associated with lower Δ 13 C under both watering regimes. This may indicate that Si fertilization had a beneficial effect on water use efficiency (WUE). Hence, Δ 13 C could be an adequate indicator of WUE in response to the exogenous supply of silicon to chickpea plants. Our results highlight that Si is not only involved in amelioration of growth and in maintaining of water status but it can be considered as an important element for the symbiotic performance of chickpea plants. It can be concluded that synergistic effect of silicon and potassium fertilization with adequate irrigation improves growth and nitrogen fixation in chickpea plants.In barley plants, solely added K or in combination with adequate rate of Si (Si 1 00) were more effective in alleviating water stress and producing higher yield in barley plants than solely added Si. However, the latter nutrient was found to be more effective than the former in producing

  10. [Effects of water stress and temperature on gas exchange and chlorophyll fluorescence of Sinocalycanthus chinensis leaves].

    Science.gov (United States)

    Ke, Shi-sheng; Jin, Ze-xin

    2008-01-01

    Sinocalycanthus chinensis is an endangered species in Sinocalycanthus, and only distributed in Zhejiang Province of China. This paper studied the photosynthetic responses of 2-year-old pot-cultured S. chinensis to different levels of water stress and temperature. The results indicated that under mild and moderate water stress, the net photosynthetic rate (Pn) of S. chinensis leaves was decreased to 92.3% and 74.3% of the control, respectively, which was mainly attributed to stomatal limitation; and under severe water stress, the Pn was decreased to 44.4% of the control, which might be mainly linked to non-stomatal limitation. The appropriate temperature for S. chinensis photosynthesis was from 20 degrees C to 28 degrees C. At 39 degrees C, the Pn, water use efficiency (WUE), and maximal photochemistry efficiency (Fv/Fm) were decreased significantly, while the dark respiration rate (Rd) and transpiration rate (Tr) were enhanced significantly. With increasing water stress and temperature, some photosynthetic parameters including light saturation point (LSP), apparent quantum yield (AQY) and maximal CO2 assimilation rate (Pmax) decreased to certain extents, while light compensation point (LCP) increased, suggesting that both severe water stress and higher temperature were the important environmental factors affecting the survival of S. chinensis.

  11. 14C-incorporation into sugars and organic acids of water-stressed maize leaves

    International Nuclear Information System (INIS)

    Becker, T.; Fock, H.

    1986-01-01

    The incorporation of 14 C into sugars and some organic acids of maize leaves has been studied in relation to the leaf water potential by feeding 14 CO 2 (370 ppm) for 1,2 and 4 min during steady state photosynthesis at 25 0 C (PAR = 800 μmol m -2 s -1 ). The relative specific radioactivity (RSA) of the sugars was low (0.2% after 4 min) at -0.62 MPa (control) and decreased by about 50% when psi dropped to -0.95 MPa. The authors conclude that the low rate of photosynthetic sugar synthesis in maize leaves decreased during water stress. The RSA of malate was extremely low at -0.62 MPa (0.02%). This result may be the consequence of the large pool size of malate in maize leaves. The authors presume that there are two malate pools present in maize leaves, a small metabolic pool and a larger storage pool. The RSA of malate decreased during the stress period. This is consistent with the decline in net CO 2 uptake during water stress. The pool sizes of citrate and isocitrate increased when psi dropped to -0.95 MPa. As practically no radioactivity was detected in these organic acids, they conclude that these compounds are synthesized from unlabelled precursors during water stress

  12. Xanthophylls and abscisic acid biosynthesis in water-stressed bean leaves

    International Nuclear Information System (INIS)

    Li, Y.; Walton, D.C.

    1987-01-01

    Experiments were designed to obtain evidence about the possible role of xanthophylls as abscisic acid (ABA) precursors in water-stressed leaves of Phaseolus vularis L. Leaves were exposed to 14 CO 2 and the specific activities of several major leaf xanthophylls and stress-induced ABA were determined after a chase in 12 CO 2 for varying periods of time. The ABA specific radioactivities were about 30 to 70% of that of lutein and violaxanthin regardless of the chase period. The specific activity of neoxanthin, however, was only about 15% of that of ABA. The effects of fluridone on xanthophyll and ABA levels and the extent of labeling of both from 14 CO 2 were determined. Fluridone did not inhibit the accumulation of ABA when leaves were stressed once, although subsequent stresses in the presence of fluridone did lead to a reduced ABA accumulation. The incorporation of 14 C from 14 CO 2 into ABA and the xanthophylls was inhibited by fluridone and to about the same extent. The incorporation of 18 O into ABA from violaxanthin which had been labeled in situ by means of the violaxanthin cycle was measured. The results indicated that a portion of the ABA accumulated during stress was formed from violaxanthin which had been labeled with 18 O. The results of these experiments are consistent with a preformed xanthophyll(s) as the major ABA precursor in water-stressed bean leaves

  13. Xanthophylls and abscisic acid biosynthesis in water-stressed bean leaves

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    Li, Y.; Walton, D.C.

    1987-12-01

    Experiments were designed to obtain evidence about the possible role of xanthophylls as abscisic acid (ABA) precursors in water-stressed leaves of Phaseolus vularis L. Leaves were exposed to /sup 14/CO/sub 2/ and the specific activities of several major leaf xanthophylls and stress-induced ABA were determined after a chase in /sup 12/CO/sub 2/ for varying periods of time. The ABA specific radioactivities were about 30 to 70% of that of lutein and violaxanthin regardless of the chase period. The specific activity of neoxanthin, however, was only about 15% of that of ABA. The effects of fluridone on xanthophyll and ABA levels and the extent of labeling of both from /sup 14/CO/sub 2/ were determined. Fluridone did not inhibit the accumulation of ABA when leaves were stressed once, although subsequent stresses in the presence of fluridone did lead to a reduced ABA accumulation. The incorporation of /sup 14/C from /sup 14/CO/sub 2/ into ABA and the xanthophylls was inhibited by fluridone and to about the same extent. The incorporation of /sup 18/O into ABA from violaxanthin which had been labeled in situ by means of the violaxanthin cycle was measured. The results indicated that a portion of the ABA accumulated during stress was formed from violaxanthin which had been labeled with /sup 18/O. The results of these experiments are consistent with a preformed xanthophyll(s) as the major ABA precursor in water-stressed bean leaves.

  14. Violaxanthin is an abscisic acid precursor in water-stressed dark-grown bean leaves

    International Nuclear Information System (INIS)

    Li, Yi; Walton, D.C.

    1990-01-01

    The leaves a dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of ciolaxanthin, 9'-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were stressed for 7 hours. Early in the stress period, reductions in xanthophylls were greater than the accumulation of ABA and its metabolites, suggesting the accumulation of an intermediate which was subsequently converted to ABA. Leaves which were detached, but no stressed, did not accumulate ABA nor were their xanthophyll levels reduced. Leaves from plants that had been sprayed with cycloheximido did not accumulate ABA when stressed, nor were their xanthophyll levels reduced significantly. Incubation of dark-grown stressed leaves in an 18 O 2 -containing atmosphere resulted in the synthesis of ABA with levels of 18 O in the carboxyl group that were virtually identical to those observed in light-grown leaves. The results of these experiments indicate that violaxanthin is an ABA precursor in stressed dark-grown leaves, and they are used to suggest several possible pathways from violaxanthin to ABA

  15. Violaxanthin is an abscisic acid precursor in water-stressed dark-grown bean leaves

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    Li, Yi; Walton, D.C. (State Univ. of New York, Syracuse (USA))

    1990-03-01

    The leaves a dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of ciolaxanthin, 9{prime}-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were stressed for 7 hours. Early in the stress period, reductions in xanthophylls were greater than the accumulation of ABA and its metabolites, suggesting the accumulation of an intermediate which was subsequently converted to ABA. Leaves which were detached, but no stressed, did not accumulate ABA nor were their xanthophyll levels reduced. Leaves from plants that had been sprayed with cycloheximido did not accumulate ABA when stressed, nor were their xanthophyll levels reduced significantly. Incubation of dark-grown stressed leaves in an {sup 18}O{sub 2}-containing atmosphere resulted in the synthesis of ABA with levels of {sup 18}O in the carboxyl group that were virtually identical to those observed in light-grown leaves. The results of these experiments indicate that violaxanthin is an ABA precursor in stressed dark-grown leaves, and they are used to suggest several possible pathways from violaxanthin to ABA.

  16. Hormonal and Hydroxycinnamic Acids Profiles in Banana Leaves in Response to Various Periods of Water Stress

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    Jalel Mahouachi

    2014-01-01

    Full Text Available The pattern of change in the endogenous levels of several plant hormones and hydroxycinnamic acids in addition to growth and photosynthetic performance was investigated in banana plants (Musa acuminata cv. “Grand Nain” subjected to various cycles of drought. Water stress was imposed by withholding irrigation for six periods with subsequent rehydration. Data showed an increase in abscisic acid (ABA and indole-3-acetic acid (IAA levels, a transient increase in salicylic acid (SA concentration, and no changes in jasmonic acid (JA after each period of drought. Moreover, the levels of ferulic (FA and cinnamic acids (CA were increased, and plant growth and leaf gas exchange parameters were decreased by drought conditions. Overall, data suggest an involvement of hormones and hydroxycinnamic acids in plant avoidance of tissue dehydration. The increase in IAA concentration might alleviate the senescence of survival leaves and maintained cell elongation, and the accumulation of FA and CA could play a key role as a mechanism of photoprotection through leaf folding, contributing to the effect of ABA on inducing stomatal closure. Data also suggest that the role of SA similarly to JA might be limited to a transient and rapid increase at the onset of the first period of stress.

  17. Hormonal and hydroxycinnamic acids profiles in banana leaves in response to various periods of water stress.

    Science.gov (United States)

    Mahouachi, Jalel; López-Climent, María F; Gómez-Cadenas, Aurelio

    2014-01-01

    The pattern of change in the endogenous levels of several plant hormones and hydroxycinnamic acids in addition to growth and photosynthetic performance was investigated in banana plants (Musa acuminata cv. "Grand Nain") subjected to various cycles of drought. Water stress was imposed by withholding irrigation for six periods with subsequent rehydration. Data showed an increase in abscisic acid (ABA) and indole-3-acetic acid (IAA) levels, a transient increase in salicylic acid (SA) concentration, and no changes in jasmonic acid (JA) after each period of drought. Moreover, the levels of ferulic (FA) and cinnamic acids (CA) were increased, and plant growth and leaf gas exchange parameters were decreased by drought conditions. Overall, data suggest an involvement of hormones and hydroxycinnamic acids in plant avoidance of tissue dehydration. The increase in IAA concentration might alleviate the senescence of survival leaves and maintained cell elongation, and the accumulation of FA and CA could play a key role as a mechanism of photoprotection through leaf folding, contributing to the effect of ABA on inducing stomatal closure. Data also suggest that the role of SA similarly to JA might be limited to a transient and rapid increase at the onset of the first period of stress.

  18. Evaluation of drought tolerance and yield capacity of barley (hordeum vulgare) genotypes under irrigated and water-stressed conditions

    International Nuclear Information System (INIS)

    Khokhar, M.I.; Silva, J.A.T.D

    2012-01-01

    Twelve barley genotypes developed through different selection methods were evaluated under drought and irrigated conditions. The results of a correlation matrix revealed highly significant associations between Grain Yield (Yp) and Mean Productivity (MP), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP) and Yield Index (Yi) under irrigated conditions while the Mean Productivity (MP), Yield Stability Index (Yi), Stress Tolerance Index (STI), Geometric Mean Productivity (GMP) and Yield Index (Yi) had a high response under stressed condition. Based on a principal component analysis, Geometric Mean Productivity (GMP), Mean Productivity (MP) and Stress Tolerance Index (STI) were considered to be the best parameters for selection of drought-tolerant genotypes. The 2-row barley genotypes B-07023 and B-07021 performed better in yield response under drought conditions and were more stable under stress conditions. Furthermore, drought stress reduced the yield of some genotypes while others were tolerant to drought, suggesting genetic variability in this material for drought tolerance. (author)

  19. Influence of yellow rust infection on /sup 32/P transport in detached barley leaves

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J. (Akademie der Landwirtschaftswissenschaften der DDR, Aschersleben. Inst. fuer Phytopathologie)

    1982-01-01

    Several barley cultivars (Hordeum vulgare L.) differing in their resistance to yellow rust (Puccinia striiformis West.) were tested for relationships between changes of /sup 32/P transport in detached leaves and resistance to yellow rust disease. Investigation carried out with detached second leaves from plants infected at their first leaf revealed a matter transport in these leaves changed by the infection. Transport was also influenced by inoculation with yellow rust uredospores. In that case rust infection influenced the basipetal transport less strongly in resistent plants than in susceptible ones. Connected with the findings the influence of fungal substances on transport processes is discussed in general.

  20. Influence of yellow rust infextion on 32P transport in detached barley leaves

    International Nuclear Information System (INIS)

    Schubert, J.

    1982-01-01

    Several barley cultivars (Hordeum vulgare L.) differing in their resistance to yellow rust (Puccinia striiformis West.) were tested for relationships between changes of 32 P transport in detached leaves and resistance to yellow rust disease. Investigation carried out with detached second leaves from plants infected at their first leaf revealed a matter transport in these leaves changed by the infection. Transport was also influenced by inoculation with yellow rust uredospores. In that case rust infection influenced the basipetal transport less strongly in resistent plants than in susceptible ones. Connected with the findings the influence of fungal substances on transport processes is discussed in general. (author)

  1. Evaluation of nitrogen status and total chlorophyll in longkong (Aglaia dookkoo Griff. leaves under water stress using a chlorophyll meter

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    Sdoodee, S.

    2005-07-01

    Full Text Available A chlorophyll meter (SPAD-502 was used to assess nitrogen status and total chlorophyll in longkong leaves, leaves from twelve of 10-year-old trees grown in the experimental plot at Prince of Songkla University, Songkhla province. The relationship between SPAD-502 meter reading and nitrogen status and total chlorophyll content analyzed in the laboratory was evaluated during 8 months (May-December 2003. It was found that the trend of the relationships in each month was similar. There was no significant differenceamong regression linears of all months. The data of 8 months showed that SPAD-reading and nitrogen content, and SPAD-reading and total chlorophyll content were related in a positive manner. They were Y = 0.19X+10.10, r = 0.76** (n = 240, and Y = 0.43X-7.89, r = 0.79** (n = 400, respectively. The SPAD-502 was then used to assess total nitrogen and total chlorophyll content during imposed water stress. Fifteen 4-yearold plants were grown in pots (each pot containing 50 kg soil volume. The experiment was arranged in acompletely randomized design with 3 treatments: (1 daily watering (2 once watering on day 7 (3 no watering with 5 replications during 14 days of the experimental period. Measurements showed a continuous decrease of SPAD-reading in the treatment of no watering. On day 14, a significant difference of SPAD- reading values between the treatment of daily watering and no watering was found. Then, the values of nitrogen content and total chlorophyll were assessed by using the linear regression equations. From the result, it is suggested that the measurement by chlorophyll meter is a rapid technique for the evaluation of total chlorophyll and nitrogen status in longkong leaves during water stress.

  2. Effect of Different Level of Water Stress and Nitrogen Fertilizer on Yield and Yield Components of Barley in Badjgah (Fars province

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    ali asghar ghaemi

    2016-02-01

    plit-plot layout with three deficit irrigation treatments ( consisted of irrigation with 100% ,75% and 50% of crop water consumption use and three nitrogen fertilizer treatments (included 75 kg/ha, 150 kg/ha and 225 kg/ha with three replication. A total of 27 experimental plots were carried out. In each plot, 11-row barley with 30 cm spacing apart and 5 cm depth were planted by hand. Barley seeding rates on the basis of 200 kg per hectare were planted in each experimental plots in the first half of November.Nitrogen requirement was applied in three stages of the growth: 30% before cultivation, 40% in shooting stage and 30% in barleyclusterstage.Irrigation treatments included 100% = W1, in this treatment 100% treatment crop water requirement was estimated by neutron meter (this was the control treatment which received muchwater as neededand no water stress in all growth stages,75% = W2: in this treatment 75% of the crop water requirement was applied, and 50% = W3: the 50% of the crop water requirement plant was applied. During differentgrowth stages plant required data were collected and the parametersinclude: grain yield, biological yield, straw yield, number of grains per spike, spike per unit area, grain protein, harvest index, 1000 grain weight, number of unfilled and filled grain per spike and efficiency of water use were determined . Tests to determine the percentage of leaf nitrogen and protein was measured by kjeldahldevice(6405UV / VIS. The software SAS (version.9.1 was used to analyze data and graphs were drawn in Excel. Results and Discussion: results showed that the highest yield,yield component was obtained on 100% irrigation and 225 kg/ha fertilizer treatments. Also it was observed that at the certain level of irrigation treatment by increasing the amount of nitrogen fertilizer the amount of this parameters will be increased.Result also showed that at the certain level of nitrogen fertilizer by decreasing water, the maximum plant response to the nitrogen

  3. Optimization of microwave-assisted extraction of flavonoids from young barley leaves

    Science.gov (United States)

    Gao, Tian; Zhang, Min; Fang, Zhongxiang; Zhong, Qifeng

    2017-01-01

    A central composite design combined with response surface methodology was utilized to optimise microwave-assisted extraction of flavonoids from young barley leaves. The results showed that using water as solvent, the optimum conditions of microwave-assisted extraction were extracted twice at 1.27 W g-1 microwave power and liquid-solid ratio 34.02 ml g-1 for 11.12 min. The maximum extraction yield of flavonoids (rutin equivalents) was 80.78±0.52%. Compared with conventional extraction method, the microwave-assisted extraction was more efficient as the extraction time was only 6.18% of conventional extraction, but the extraction yield of flavonoids was increased by 5.47%. The main flavonoid components from the young barley leaf extract were probably 33.36% of isoorientin-7-O-glueoside and 54.17% of isovitexin-7-O-glucoside, based on the HPLC-MS analysis. The barley leaf extract exhibited strong reducing power as well as the DPPH radical scavenging capacity.

  4. Polyamine regulates tolerance to water stress in leaves of white clover associated with antioxidant defense and dehydrin genes via involvement in calcium messenger system and hydrogen peroxide signaling

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    Zhou eLi

    2015-10-01

    Full Text Available Endogenous polyamine (PA may play a critical role in tolerance to water stress in plants acting as a signaling molecule activator. Water stress caused increases in endogenous PA content in leaves, including putrescine (Put, spermidine (Spd, and spermine (Spm. Exogenous application of Spd could induce the instantaneous H2O2 burst and accumulation of cytosolic free Ca2+, and activate NADPH oxidase and CDPK gene expression in cells. To a great extent, PA biosynthetic inhibitor reduced the water stress-induced H2O2 accumulation, free cytosolic Ca2+ release, antioxidant enzyme activities and genes expression leading to aggravate water stress-induced oxidative damage, while these suppressing effects were alleviated by the addition of exogenous Spd, indicating PA was involved in water stress-induced H2O2 and cytosolic free Ca2+ production as well as stress tolerance. Dehydrin genes (Y2SK, Y2K, and SK2 were showed to be highly responsive to exogenous Spd. PA-induced antioxidant defense and dehydrin genes expression could be blocked by the scavenger of H2O2 and the inhibitors of H2O2 generation or Ca2+ channels blockers, a calmodulin antagonist, as well as the inhibitor of CDPK. These findings suggested that PA regulated tolerance to water stress in white clover associated with antioxidant defenses and dehydrins via involvement in the calcium messenger system and H2O2 signaling pathways. PA-induced H2O2 production required Ca2+ release, while PA-induced Ca2+ release was also essential for H2O2 production, suggesting an interaction between PA-induced H2O2 and Ca2+ signaling.

  5. Changes in the free amino acid composition of Capsicum annuum (pepper) leaves in response to Myzus persicae (green peach aphid) infestation. A comparison with water stress.

    Science.gov (United States)

    Florencio-Ortiz, Victoria; Sellés-Marchart, Susana; Zubcoff-Vallejo, José; Jander, Georg; Casas, José L

    2018-01-01

    Amino acids play a central role in aphid-plant interactions. They are essential components of plant primary metabolism, function as precursors for the synthesis of defense-related specialized metabolites, and are major growth-limiting nutrients for aphids. To quantify changes in the free amino acid content of pepper (Capsicum annuum L.) leaves in response to green peach aphid (Myzus persicae Sulzer) feeding, plants were infested with a low (20 aphids/plant) or a high (200 aphids/plant) aphid density in time-course experiments ranging from 3 hours to 7 days. A parallel experiment was conducted with pepper plants that had been subjected to water stress. Factor Analysis of Mixed Data revealed a significant interaction of time x density in the free amino acid response of aphid-infested leaves. At low aphid density, M. persicae did not trigger a strong response in pepper leaves. Conversely, at high density, a large increase in total free amino acid content was observed and specific amino acids peaked at different times post-infestation. Comparing aphid-infested with water-stressed plants, most of the observed differences were quantitative. In particular, proline and hydroxyproline accumulated dramatically in response to water stress, but not in response to aphid infestation. Some additional differences and commonalities between the two stress treatments are discussed.

  6. Pathogen-Induced Changes in the Antioxidant Status of the Apoplast in Barley Leaves

    Science.gov (United States)

    Vanacker, Hélène; Carver, Tim L.W.; Foyer, Christine H.

    1998-01-01

    Leaves of two barley (Hordeum vulgare L.) isolines, Alg-R, which has the dominant Mla1 allele conferring hypersensitive race-specific resistance to avirulent races of Blumeria graminis, and Alg-S, which has the recessive mla1 allele for susceptibility to attack, were inoculated with B. graminis f. sp. hordei. Total leaf and apoplastic antioxidants were measured 24 h after inoculation when maximum numbers of attacked cells showed hypersensitive death in Alg-R. Cytoplasmic contamination of the apoplastic extracts, judged by the marker enzyme glucose-6-phosphate dehydrogenase, was very low (less than 2%) even in inoculated plants. Dehydroascorbate, glutathione, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, monodehydroascorbate reductase, and dehydroascorbate reductase were present in the apoplast. Inoculation had no effect on the total foliar ascorbate pool size or the redox state. The glutathione content of Alg-S leaves and apoplast decreased, whereas that of Alg-R leaves and apoplast increased after pathogen attack, but the redox state was unchanged in both cases. Large increases in foliar catalase activity were observed in Alg-S but not in Alg-R leaves. Pathogen-induced increases in the apoplastic antioxidant enzyme activities were observed. We conclude that sustained oxidation does not occur and that differential strategies of antioxidant response in Alg-S and Alg-R may contribute to pathogen sensitivity. PMID:9662553

  7. Characterization and partial purification of beta-1,3-D-glucan (callose) synthase from barley (Hordeum vulgare) leaves

    DEFF Research Database (Denmark)

    Pedersen, L.H.; Jacobsen, S.; Hejgaard, J.

    1993-01-01

    The plasma membrane bound beta-1,3-D-glucan (callose) synthase. assumed to be involved in the resistance to the powdery mildew fungus (Erysiphe graminis f.sp. hordei), was partially purified from a microsomal fraction of green barley leaves (Hordeum vulgare L.). Plasma membranes were enriched...

  8. Microarray Analysis of Late Response to Boron Toxicity in Barley (Hordeum vulgare L.) Leaves

    NARCIS (Netherlands)

    Oz, M.T.; Yilmaz, R.; Eyidogan, F.; Graaff, de L.H.; Yucel, M.; Oktem, H.A.

    2009-01-01

    DNA microarrays, being high-density and high-throughput, allow quantitative analyses of thousands of genes and their expression patterns in parallel. In this study, Barley1 GereChip was used to investigate transcriptome changes associated with boron (B) toxicity in a sensitive barley cultivar

  9. Members of the barley NAC transcription factor gene family show differential co-regulation with senescence-associated genes during senescence of flag leaves

    DEFF Research Database (Denmark)

    Christiansen, Michael W; Gregersen, Per L.

    2014-01-01

    -expressed with members of the NAC gene family. In conclusion, a list of up to 15 NAC genes from barley that are strong candidates for being regulatory factors of importance for senescence and biotic stress-related traits affecting the productivity of cereal crop plants has been generated. Furthermore, a list of 71...... in the NAC transcription factor family during senescence of barley flag leaves was studied. Several members of the NAC transcription factor gene family were up-regulated during senescence in a microarray experiment, together with a large range of senescence-associated genes, reflecting the coordinated...... activation of degradation processes in senescing barley leaf tissues. This picture was confirmed in a detailed quantitative reverse transcription–PCR (qRT–PCR) experiment, which also showed distinct gene expression patterns for different members of the NAC gene family, suggesting a group of ~15 out of the 47...

  10. Possible role for abscisic acid in regulation of photosynthetic and photorespiratory carbon metabolism in barley leaves

    International Nuclear Information System (INIS)

    Popova, L.P.; Tsonev, T.D.; Vaklinova, S.G.

    1987-01-01

    The influence of abscisic acid (ABA) on carbon metabolism, rate of photorespiration, and the activity of the photorespiratory enzymes ribulose bisphosphate oxygenase and glycolate oxidase in 7-day-old barley seedlings (Hordeum vulgare L. var. Alfa) was investigated. Plants treated with ABA had enhanced incorporation of labeled carbon from 14 CO 2 into glycolic acid, glycine, and serine, while 14 C incorporation into 3-phosphoglyceric acid and sugarphosphate esters was depressed. Parallel with this effect, treated plants showed a rise in activity of RuBP oxygenase and glycolic acid oxidase. The rate of photorespiration was increased twofold by ABA treatment at IO -6 molar while the CO 2 -compensation point increased 46% and stomatal resistance increased more than twofold over control plants

  11. under water stress conditio

    African Journals Online (AJOL)

    A. Thameur

    2012-05-17

    adjustment trait variation in barley (Hordeum vulgare L.). Theor. Appl. Genet., 96: 688-698. Thameur A, Ferchichi A, López-Carbonell M (2011). Quantification of free and conjugated abscisic acid in five genotypes of barley. (Hordeum ...

  12. Genotype-dependent variation in the transpiration efficiency of plants and photosynthetic activity of flag leaves in spring barley under varied nutrition.

    Science.gov (United States)

    Krzemińska, Anetta; Górny, Andrzej G

    2003-01-01

    In the study, spring barley genotypes of various origin and breeding history were found to show a broad genetic variation in the vegetative and generative measures of the whole-plant transpiration efficiency (TE), photosynthesis (A) and transpiration (E) rates of flag leaves, leaf efficiency of gas exchange (A/E) and stress tolerance (T) when grown till maturity in soil-pots under high and reduced NPK supplies. Broad-sense heritabilities for the characteristics ranged from 0.61 to 0.87. Significant genotype-nutrition interactions were noticed, constituting 19-23% of the total variance in TE measures. The results suggest that at least some 'exotic' accessions from Ethiopia, Syria, Morocco and/or Tibet may serve as attractive genetic sources of novel variations in TE, T and A for the breeding of barleys of improved adaptation to less favourable fertilisation.

  13. Effects of INH, DNP, 2, 4-D and CMU on the sugar content of the barley and maize leaves

    International Nuclear Information System (INIS)

    Fernandez, J.; Sancho, P.

    1979-01-01

    1 ppm of the chemicals in nutritive solution was absorbed by barley and maize roots during 24 and 48 hours in dark or light conditioners in order to determine the best conditions for the obtention of labelled sugars with high specific activity. Results show that the highest specific activity was obtained in maize plants treated with DNP for 24 hours in dark conditions. (Author) 51 refs

  14. Loss of the precise control of photosynthesis and increased yield of non-radiative dissipation of exitation energy after mild heat treatment of barley leaves

    International Nuclear Information System (INIS)

    Bukhov, N.G.; Boucher, N.; Carpentier, R.

    1998-01-01

    The after effects of a short exposure of intact barley leaves to moderately elevated temperature (40°C, 5 min) on the induction transients and the irradiance dependencies of photosynthesis and chlorophyll fluorescence are presented. This mild heat treatment strongly reduced the oscillations in the rate of photosynthesis and in the yield of chlorophyll fluorescence. However, only a 25% irreversible inhibition of maximum photosynthetic capacity of photosystem II (PSII) measured by oxygen evolution was produced and the intrinsic quantum yield of PSII measured by the chlorophyll fluorescence ratio (F m - F o )/Fm decreased by only 15%. In contrast, the above treatment increased radiationless dissipation processes in PSII by a factor of two. In heat-treated leaves, photosynthesis was not saturated even by strong light. Both ΔpH-dependent quenching of excitons in PSII (including formation of zeaxanthin) and state 1/state 2 transition were found to be stimulated. Heat exposure enhanced the control of PSII activity by PSI, as evidenced by a significant increase in the quenching effect of far-red light on the maximum yield of chlorophyll fluorescence. It was deduced that after mild heat treatment, the photosynthetic apparatus in leaves lacks the precise coordinating control of electron transport and carbon metabolism owing to the inability of PSII to support electron transport at a level adequate for carbon metabolism. This effect was not related to the small irreversible thermal damage to PSII, but was rather due to a significant increase in non-photochemical quenching of excitation energy. (author)

  15. An eceriferum locus, cer-zv, is associated with a defect in cutin responsible for water retention in barley (Hordeum vulgare) leaves.

    Science.gov (United States)

    Li, Chao; Wang, Aidong; Ma, Xiaoying; Pourkheirandish, Mohammad; Sakuma, Shun; Wang, Ning; Ning, Shunzong; Nevo, Eviatar; Nawrath, Christiane; Komatsuda, Takao; Chen, Guoxiong

    2013-03-01

    Drought limits plant growth and threatens crop productivity. A barley (Hordeum vulgare) ethylene imine-induced monogenic recessive mutant cer-zv, which is sensitive to drought, was characterized and genetically mapped in the present study. Detached leaves of cer-zv lost 34.2 % of their initial weight after 1 h of dehydration. The transpiration was much higher in cer-zv leaves than in wild-type leaves under both light and dark conditions. The stomata of cer-zv leaves functioned normally, but the cuticle of cer-zv leaves showed increased permeability to ethanol and toluidine blue dye. There was a 50-90 % reduction in four major cutin monomers, but no reduction in wax loads was found in the cer-zv mutant as compared with the wild type. Two F(2) mapping populations were established by the crosses of 23-19 × cer-zv and cer-zv × OUH602. More polymorphisms were found in EST sequences between cer-zv and OUH602 than between cer-zv and 23-19. cer-zv was located in a pericentromeric region on chromosome 4H in a 10.8 cM interval in the 23-19 × cer-zv map based on 186 gametes tested and a 1.7 cM interval in the cer-zv × OUH602 map based on 176 gametes tested. It co-segregated with EST marker AK251484 in both maps. The results indicated that the cer-zv mutant is defective in cutin, which might be responsible for the increased transpiration rate and drought sensitivity, and that the F(2) of cer-zv × OUH602 might better facilitate high resolution mapping of cer-zv.

  16. Dehydrin from citrus, which confers in vitro dehydration and freezing protection activity, is constitutive and highly expressed in the flavedo of fruit but responsive to cold and water stress in leaves.

    Science.gov (United States)

    Sanchez-Ballesta, Maria Teresa; Rodrigo, Maria Jesus; Lafuente, Maria Teresa; Granell, Antonio; Zacarias, Lorenzo

    2004-04-07

    A cDNA encoding a dehydrin was isolated from the flavedo of the chilling-sensitive Fortune mandarin fruit (Citrus clementina Hort. Ex Tanaka x Citrus reticulata Blanco) and designed as Crcor15. The predicted CrCOR15 protein is a K2S member of a closely related dehydrin family from Citrus, since it contains two tandem repeats of the unusual Citrus K-segment and one S-segment (serine cluster) at an unusual C-terminal position. Crcor15 mRNA is consistently and highly expressed in the flavedo during fruit development and maturation. The relative abundance of Crcor15 mRNA in the flavedo was estimated to be higher than 1% of total RNA. The high mRNA level remained unchanged during fruit storage at chilling (2 degrees C) and nonchilling (12 degrees C) temperatures, and it was depressed by a conditioning treatment (3 days at 37 degrees C) that induced chilling tolerance. Therefore, the expression of Crcor15 appears not to be related to the acquisition of chilling tolerance in mandarin fruits. However, Crcor15, which was barely detected in unstressed mandarin leaves, was rapidly induced in response to both low temperature and water stress. COR15 protein was expressed in Escherichia coli, and the purified protein conferred in vitro protection against freezing and dehydration inactivation. The potential role of Citrus COR15 is discussed.

  17. Cytokinin Activity in Water-stressed Shoots 1

    Science.gov (United States)

    Itai, Chanan; Vaadia, Yoash

    1971-01-01

    Water stress applied to the plant shoot through enhanced evaporative demands reduced cytokinin activity in extracts of xylem exudate and leaves. This reduction resembled the changes in cytokinin activity caused by water stress applied to the root. Cytokinin activity in detached wilting leaves decreased rapidly. Recovery took place after several hours in a humid chamber. Experiments with 14C-kinetin indicated that the mechanism of the inactivation and its reversal involve a chemical transformation of the cytokinin molecule. PMID:16657585

  18. Consecutive monitoring of lifelong production of conidia by individual conidiophores of Blumeria graminis f. sp. hordei on barley leaves by digital microscopic techniques with electrostatic micromanipulation.

    Science.gov (United States)

    Moriura, Nobuyuki; Matsuda, Yoshinori; Oichi, Wataru; Nakashima, Shinya; Hirai, Tatsuo; Sameshima, Takeshi; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Higashi, Katsuhide; Toyoda, Hideyoshi

    2006-01-01

    Conidial formation and secession by living conidiophores of Blumeria graminis f. sp. hordei on barley leaves were consecutively monitored using a high-fidelity digital microscopic technique combined with electrostatic micromanipulation to trap the released conidia. Conidial chains formed on conidiophores through a series of septum-mediated division and growth of generative cells. Apical conidial cells on the conidiophores were abstricted after the conidial chains developed ten conidial cells. The conidia were electrically conductive, and a positive charge was induced in the cells by a negatively polarized insulator probe (ebonite). The electrostatic force between the conidia and the insulator was used to attract the abstricted conidia from the conidiophores on leaves. This conidium movement from the targeted conidiophore to the rod was directly viewed under the digital microscope, and the length of the interval between conidial septation and secession, the total number of the conidia produced by a single conidiophore, and the modes of conidiogenesis were clarified. During the stage of conidial secession, the generative cells pushed new conidial cells upwards by repeated division and growth. The successive release of two apical conidia was synchronized with the successive septation and growth of a generative cell. The release ceased after 4-5 conidia were released without division and growth of the generative cell. Thus, the life of an individual conidiophore (from the erection of the conidiophore to the release of the final conidium) was shown to be 107 h and to produce an average of 33 conidia. To our knowledge, this is the first report on the direct estimation of life-long conidial production by a powdery mildew on host leaves.

  19. Improving drought and salinity tolerance in barley by application of salicylic acid and potassium nitrate

    Directory of Open Access Journals (Sweden)

    Khalaf Ali Fayez

    2014-01-01

    Full Text Available Growth and physiological activities of barley (Hordeum vulgare L. cv. Gustoe grown in soil cultures were evaluated to recognize the ameliorative role of salicylic acid (SA and KNO3 against the negative effects of salt and water deficit stresses. Barley plants were subjected to three levels of NaCl (50, 100 and 150 mM, three levels of water stress (80%, 70% and 50% of the soil water content (SWC and the combination of 150 mM NaCl + 50 μM SA, 150 mM NaCl + 10 mM KNO3, 50% SWC + 50 μM SA and 50% SWC + 10 mM KNO3 for two weeks. Salt and water deficit stresses reduced the shoot growth, leaf photosynthetic pigments, K+ contents and provoked oxidative stress in leaves confirmed by considerable changes in soluble carbohydrate, proline, malondialdehyde (MDA, total phenolic compounds, antioxidant activity and Na+ contents. Leaf soluble protein of salt and water deficit treated plants was unaffected. The Na+/K+ ratio increased with increasing salt and water deficit treated plants. Application of 50 μM SA or 10 mM KNO3 to150 mM NaCl and/or 50% SWC treated plants improved these attributes under salt and water stresses. Soluble carbohydrates in stressed plants may have a significant role in osmotic adjustment. It can be concluded that the addition of SA or KNO3 can ameliorate the oxidative stress in barley stressed plants. This ameliorative effect might be maintained through low MDA contents and decreased Na+/K+ ratio in leaves. This study also provided evidence for the ability of barley cultivation in salt and water deficit soils due to its capacity for osmotic adjustment.

  20. Growth, Carbon Isotope Discrimination and Nitrogen Uptake in Silicon and/or Potassium Fed barley Grown under Two Watering Regimes

    Directory of Open Access Journals (Sweden)

    Kurdali, Fawaz

    2013-02-01

    Full Text Available The present pot experiment was an attempt to monitor the beneficial effects of silicon (Si and/or potassium (K applications on growth and nitrogen uptake in barley plants grown under water (FC1 and non water (FC2 stress conditions using 15N and 13C isotopes. Three fertilizer rates of Si (Si50, Si100 and Si200 and one fertilizer rate of K were used. Dry matter (DM and N yield (NY in different plant parts of barley plants was affected by Si and/ or K fertilization as well as by the watering regime level under which the plants have been grown. Solely added K or in combination with adequate rate of Si (Si 100 were more effective in alleviating water stress and producing higher yield in barley plants than solely added Si. However, the latter nutrient was found to be more effective than the former in producing higher spike's N yield. Solely added Si or in combination with K significantly reduced leaves ∆13 C reflecting their bifacial effects on water use efficiency (WUE, particularly in plants grown under well watering regime. This result indicated that Si might be involved in saving water loss through reducing transpiration rate and facilitating water uptake; consequently, increasing WUE. Although the rising of soil humidity generally increased fertilizer nitrogen uptake (Ndff and its use efficiency (%NUE in barley plants, applications of K or Si fertilizers to water stressed plants resulted in significant increments of these parameters as compared with the control. Our results highlight that Si or K is not only involved in amelioration of growth of barley plants, but can also improve nitrogen uptake and fertilizer nitrogen use efficiency particularly under water deficit conditions.

  1. Temporal versus spatial variation in leaf reflectance under changing water stress conditions

    Science.gov (United States)

    Cohen, Warren B.

    1991-01-01

    Leaf reflectance changes associated with changes in water stress were analyzed in two separate experiments. Results indicate that the variation in reflectance among collections of leaves of a given species all at the same level of water stress is at least as great as the variation in reflectance associated with changes in water stress for a given leaf collection of that species. The implications is that results from leaf reflectance-water stress studies have only limited applicability to the remote sensing of plant canopy water stress.

  2. Barley germination

    DEFF Research Database (Denmark)

    Daneri-Castro, Sergio N.; Svensson, Birte; Roberts, Thomas H.

    2016-01-01

    germination. Lastly, the application of metabolomics to barley grain germination provides essential data on biochemical processes, including insights into the formation of compounds that contribute to malt quality. To maximize the benefits of the 'omics' revolution to the malting industry, there is a need......Germination of barley grain is central to the malting industry and is a valuable model for cereal grain germination. Our current understanding of the complexity of germination at the molecular level is facilitated by access to genomic, transcriptomic, proteomic and metabolomic data. Here we review...... of germination in the context of industrial malting. For transcriptomics, recent advances in sequencing the barley genome allow next-generation sequencing approaches to reveal novel effects of variety and environment on germination. For proteomics, selection of the source tissue(s) and the protein extraction...

  3. Underground water stress release models

    Science.gov (United States)

    Li, Yong; Dang, Shenjun; Lü, Shaochuan

    2011-08-01

    The accumulation of tectonic stress may cause earthquakes at some epochs. However, in most cases, it leads to crustal deformations. Underground water level is a sensitive indication of the crustal deformations. We incorporate the information of the underground water level into the stress release models (SRM), and obtain the underground water stress release model (USRM). We apply USRM to the earthquakes occurred at Tangshan region. The analysis shows that the underground water stress release model outperforms both Poisson model and stress release model. Monte Carlo simulation shows that the simulated seismicity by USRM is very close to the real seismicity.

  4. Strobilurin fungicides induce changes in photosynthetic gas exchange that do not improve water use efficiency of plants grown under conditions of water stress.

    Science.gov (United States)

    Nason, Mark A; Farrar, John; Bartlett, David

    2007-12-01

    The effects of five strobilurin (beta-methoxyacrylate) fungicides and one triazole fungicide on the physiological parameters of well-watered or water-stressed wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soya (Glycine max Merr.) plants were compared. Water use efficiency (WUE) (the ratio of rate of transpiration, E, to net rate of photosynthesis, A(n)) of well-watered wheat plants was improved slightly by strobilurin fungicides, but was reduced in water-stressed plants, so there is limited scope for using strobilurins to improve the water status of crops grown under conditions of drought. The different strobilurin fungicides had similar effects on plant physiology but differed in persistence and potency. When applied to whole plants using a spray gun, they reduced the conductance of water through the epidermis (stomatal and cuticular transpiration), g(sw), of leaves. Concomitantly, leaves of treated plants had a lower rate of transpiration, E, a lower intercellular carbon dioxide concentration, c(i), and a lower net rate of photosynthesis, A(n), compared with leaves of control plants or plants treated with the triazole. The mechanism for the photosynthetic effects is not known, but it is hypothesised that they are caused either by strobilurin fungicides acting directly on ATP production in guard cell mitochondria or by stomata responding to strobilurin-induced changes in mesophyll photosynthesis. The latter may be important since, for leaves of soya plants, the chlorophyll fluorescence parameter F(v)/F(m) (an indication of the potential quantum efficiency of PSII photochemistry) was reduced by strobilurin fungicides. It is likely that the response of stomata to strobilurin fungicides is complex, and further research is required to elucidate the different biochemical pathways involved. Copyright (c) 2007 Society of Chemical Industry.

  5. Effects of water stress on the distribution of 14C-assimilates in young apple trees (mauls pumila mill.)

    International Nuclear Information System (INIS)

    Dong Jiankang; Deng Ximin; Zeng Xiang

    1994-01-01

    Young apple trees were treated by water stress and 14 CO 2 was fed to leaves. Distribution of assimilates in source and sink organs was determined. The results show that plant water deficit increased the proportion of 14 C-assimilates remained in source leaves, and decreased the proportion of 13 C-assimilates exported into the developing fruits. Water stress also significantly decreased the photosynthetic rate of leaves and the growth rate of plants

  6. Crop water stress maps for an entire growing season from visible and thermal UAV imagery

    DEFF Research Database (Denmark)

    Hoffmann, Helene; Jensen, Rasmus; Thomsen, Anton

    2016-01-01

    This study investigates whether a water deficit index (WDI) based on imagery from unmanned aerial vehicles (UAVs) can provide accurate crop water stress maps at different growth stages of barley and in differing weather situations. Data from both the early and late growing season are included...... to investigate whether the WDI has the unique potential to be applicable both when the land surface is partly composed of bare soil and when crops on the land surface are senescing. The WDI differs from the more commonly applied crop water stress index (CWSI) in that it uses both a spectral vegetation index (VI...... season because at this stage the remote sensing data represent crop water availability to a greater extent than they do in the early growing season, and because the WDI accounts for areas of ripe crops that no longer have the same need for irrigation. WDI maps can potentially serve as water stress maps...

  7. Comparisons of Photosynthetic Responses of Xanthium strumarium and Helianthus annuus to Chronic and Acute Water Stress in Sun and Shade.

    Science.gov (United States)

    Ben, G Y; Osmond, C B; Sharkey, T D

    1987-06-01

    We have examined the effects of mild, chronic water stress and acute water stress on two water stress sensitive plants, Xanthium strumarium and Helianthus annuus. Using a combination of the leaf disc O(2) electrode to measure the light responses of photosynthesis and 77 K fluorescence to monitor damage to the primary photochemistry, we have found the following: (a) The CO(2) saturated rate of photosynthesis at high light is the most water stress sensitive parameter measured. (b) The apparent quantum yield (moles O(2) per mole photons) was slightly, if at all, affected by mild water stress (>-1.5 megapascals). (c) Severe water stress (<-1.5 megapascals) reduced the quantum yield of photosynthesis regardless of whether the stress was applied in sun or shade. The light independent reduction of quantum yield was not associated with a reduction in 77 K fluorescence (F(v)/F(m)) indicating that the quantum yield reduction was not the result of damage to primary photochemistry. (d) The diel fluctuation in 77 K fluorescence seen in sun-exposed control leaves was greatly exaggerated in water stressed leaves because of enhanced decline in 77 K fluorescence in the morning. The rate of recovery was similar in both control and water stressed leaves. Shaded leaves showed no change in 77 K fluorescence regardless of whether water stress was imposed or not. (e) The water stress sensitive plants used in these experiments did not recover from acute water stress severe enough to reduce the quantum yield or chronic water stress which lasted long enough that light dependent damage to primary photochemistry occurred.

  8. Loss in photosynthesis during senescence is accompanied by an increase in the activity of β-galactosidase in leaves of Arabidopsis thaliana: modulation of the enzyme activity by water stress.

    Science.gov (United States)

    Pandey, Jitendra Kumar; Dash, Sidhartha Kumar; Biswal, Basanti

    2017-07-01

    The precise nature of the developmental modulation of the activity of cell wall hydrolases that breakdown the wall polysaccharides to maintain cellular sugar homeostasis under sugar starvation environment still remains unclear. In this work, the activity of β-galactosidase (EC 3.2.1.23), a cell-wall-bound enzyme known to degrade the wall polysaccharides, has been demonstrated to remarkably enhance during senescence-induced loss in photosynthesis in Arabidopsis thaliana. The enhancement in the enzyme activity reaches a peak at the terminal phase of senescence when the rate of photosynthesis is at its minimum. Although the precise nature of chemistry of the interface between the decline in photosynthesis and enhancement in the activity of the enzyme could not be fully resolved, the enhancement in its activity in dark and its suppression in light or with exogenous sugars may indicate the involvement of loss of photosynthetic production of sugars as a key factor that initiates and stimulates the activity of the enzyme. The hydrolase possibly participates in the catabolic network of cell wall polysaccharides to produce sugars for execution of energy-dependant senescence program in the background of loss of photosynthesis. Drought stress experienced by the senescing leaves accelerates the decline in photosynthesis with further stimulation in the activity of the enzyme. The stress recovery of photosynthesis and suppression of the enzyme activity on withdrawal of stress support the proposition of photosynthetic modulation of the cell-wall-bound enzyme activity.

  9. The effect of lanthanum applications on drought tolerance in barley

    International Nuclear Information System (INIS)

    Buckingham, S.; Maheswaran, J.; Peverill, K.; Meehan, B.; Stokes, J.

    1998-01-01

    Full text: Glasshouse investigations carried out by the authors on both perlite and soil, have repeatedly shown that several plant species, when treated with lanthanum, retain greater amounts of moisture under water stressed conditions. Dry matter increases under water stress have been observed in some cases. Barley plants watered to 50% field capacity, and show-ing signs of water stress, yielded 18% more dry matter when treated with 5 kg/ha and 10 kg/ha of lanthanum than control plants (P<0.05). The results of these experiments suggest that increased dry matter production in crops under periods of water stress, is likely when previously treated with lanthanum. Consequently, it is conceivable that lanthanum may have potential as an agent that induces drought tolerance in grain crops, grown in low rainfall areas. Subsequent field trials using barley as a test crop at Walpeup, in the Mallee region of Victoria have shown that in a below average rainfall year, combined soil and foliar applications of lanthanum can significantly increase grain yield. This effect was not evident when barley grown on the same soil type was treated with lanthanum under above average rainfall conditions

  10. Co-regulation of water and K(+) transport in sunflower plants during water stress recovery.

    Science.gov (United States)

    Benlloch, Manuel; Benlloch-González, María

    2016-06-01

    16-day-old sunflower (Helianthus annuus L.) plants were subjected to deficit irrigation for 12 days. Following this period, plants were rehydrated for 2 days to study plant responses to post-stress recovery. The moderate water stress treatment applied reduced growth in all plant organs and the accumulation of K(+) in the shoot. After the rehydration period, the stem recovered its growth and reached a similar length to the control, an effect which was not observed in either root or leaves. Moreover, plant rehydration after water stress favored the accumulation of K(+) in the apical zone of the stem and expanding leaves. In the roots of plants under water stress, watering to field capacity, once the plants were de- topped, rapidly favored K(+) and water transport in the excised roots. This quick and short-lived response was not observed in roots of plants recovered from water stress for 2 days. These results suggest that the recovery of plant growth after water stress is related to coordinated water and K(+) transport from the root to the apical zone of the ​​stem and expanding leaves. This stimulation of K(+) transport in the root and its accumulation in the cells of the growing zones of the ​​stem must be one of the first responses induced in the plant during water stress recovery. Copyright © 2016 Elsevier GmbH. All rights reserved.

  11. Light energy dissipation under water stress conditions

    International Nuclear Information System (INIS)

    Stuhlfauth, T.; Scheuermann, R.; Fock, H.P.

    1990-01-01

    Using 14 CO 2 gas exchange and metabolite analyses, stomatal as well as total internal CO 2 uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to -2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO 2 exchange was drastically reduced, whereas the total CO 2 uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO 2 . This CO 2 -recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO 2 recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations

  12. Light energy dissipation under water stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Stuhlfauth, T.; Scheuermann, R.; Fock, H.P. (Universitaet Kaiserslautern (West Germany))

    1990-04-01

    Using {sup 14}CO{sub 2} gas exchange and metabolite analyses, stomatal as well as total internal CO{sub 2} uptake and evolution were estimated. Pulse modulated fluorescence was measured during induction and steady state of photosynthesis. Leaf water potential of Digitalis lanata EHRH. plants decreased to {minus}2.5 megapascals after withholding irrigation. By osmotic adjustment, leaves remained turgid and fully exposed to irradiance even at severe water stress. Due to the stress-induced reduction of stomatal conductance, the stomatal CO{sub 2} exchange was drastically reduced, whereas the total CO{sub 2} uptake and evolution were less affected. Stomatal closure induced an increase in the reassimilation of internally evolved CO{sub 2}. This CO{sub 2}-recycling consumes a significant amount of light energy in the form of ATP and reducing equivalents. As a consequence, the metabolic demand for light energy is only reduced by about 40%, whereas net photosynthesis is diminished by about 70% under severe stress conditions. By CO{sub 2} recycling, carbon flux, enzymatic substrate turnover and consumption of light energy were maintained at high levels, which enabled the plant to recover rapidly after rewatering. In stressed D. lanata plants a variable fluorescence quenching mechanism, termed coefficient of actinic light quenching, was observed. Besides water conservation, light energy dissipation is essential and involves regulated metabolic variations.

  13. Brewing with fractionated barley

    NARCIS (Netherlands)

    Donkelaar, van L.H.G.

    2016-01-01

    Brewing with fractionated barley

    Beer is a globally consumed beverage, which is produced from malted barley, water, hops and yeast. In recent years, the use of unmalted barley and exogenous enzymes have become more popular because they enable simpler processing and reduced environmental

  14. The barley Jip23b gene

    DEFF Research Database (Denmark)

    Müller-Uri, Frieder; Cameron-Mills, Verena; Mundy, John

    2002-01-01

    The barley gene (Jip23) encoding a 23,000-Da protein of unknown function was isolated and shown to be induced by jasmonate methyl ester (MeJA) in leaves. 5'upstream Jip23 sequence was isolated and fused to the beta-glucuronidase gene (GUS), and this reporter was introduced by particle bombardment...

  15. Plant responses to water stress

    Science.gov (United States)

    Kar, Rup Kumar

    2011-01-01

    Terrestrial plants most often encounter drought stress because of erratic rainfall which has become compounded due to present climatic changes.Responses of plants to water stress may be assigned as either injurious change or tolerance index. One of the primary and cardinal changes in response to drought stress is the generation of reactive oxygen species (ROS), which is being considered as the cause of cellular damage. However, recently a signaling role of such ROS in triggering the ROS scavenging system that may confer protection or tolerance against stress is emerging. Such scavenging system consists of antioxidant enzymes like SOD, catalase and peroxidases, and antioxidant compounds like ascorbate, reduced glutathione; a balance between ROS generation and scavenging ultimately determines the oxidative load. As revealed in case of defence against pathogen, signaling via ROS is initiated by NADPH oxidase-catalyzed superoxide generation in the apoplastic space (cell wall) followed by conversion to hydrogen peroxide by the activity of cell wall-localized SOD. Wall peroxidase may also play role in ROS generation for signaling. Hydrogen peroxide may use Ca2+ and MAPK pathway as downstream signaling cascade. Plant hormones associated with stress responses like ABA and ethylene play their role possibly via a cross talk with ROS towards stress tolerance, thus projecting a dual role of ROS under drought stress. PMID:22057331

  16. Dielectric Response of Corn Leaves to Water Stress

    NARCIS (Netherlands)

    van Emmerik, T.H.M.; Steele-Dunne, S.C.; Judge, J; van de Giesen, N.C.

    2016-01-01

    Radar backscatter from vegetated surface is sensitive to direct backscatter from the canopy, and two-way attenuation of the signal as it travels through the canopy. Both mechanisms are affected by the dielectric properties of {the individual elements of the canopy, which are primarily a function of

  17. Winter barley mutants created in the Ukraine

    International Nuclear Information System (INIS)

    Zayats, O.M.

    2001-01-01

    Full text: Increasing fodder and protein production is one of the objectives of the development of agriculture in Ukraine. Higher productivity of fodder crops, due to new highly productive varieties, is the means to meet this aim. Winter barley is an important crop for fodder purposes. The climate of the Ukraine is favourable for growing this crop. The areas used for the growth of winter barley are however, small (500,000-550,000 ha) and there is a shortage of good quality varieties. The main aim of the work was therefore to create new varieties of highly productive winter barley, of good quality. The new varieties and mutation lines of winter barley were created under the influence of water solutions of N-nitroso-N-methylurea (NMH - 0,012, 0,005%), N-nitroso-N-ethylurea (NEH - 0,05; 0.025; 0,012%) ethyleneimine (EI - 0,02; 0,01; 0,005%) on winter barley seeds of the varieties of local and foreign selections. On the basis of many years of investigations (1984-94) the following mutations were described: hard-grained, winter-hardiness, earliness, middle-maturity, late-maturity, wide and large leaves, narrow leaves, multinodal, great number of leaves, great number of flowers, strong stem (lodging resistant), tallness, semi-dwarfness, dwarfness, and high productivity. Particularly valuable are mutants with high productivity of green bulk. Their potential yield is 70 t/ha. As a result of the work two varieties of winter barley 'Shyrokolysty' and 'Kormovy' were released into the State register of plant varieties of the Ukraine. The other valuable mutant genotypes are used in cross breeding programmes. (author)

  18. Water stress strengthens mutualism among ants, trees, and scale insects.

    Directory of Open Access Journals (Sweden)

    Elizabeth G Pringle

    2013-11-01

    Full Text Available Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  19. Water Stress Strengthens Mutualism Among Ants, Trees, and Scale Insects

    Science.gov (United States)

    Pringle, Elizabeth G.; Akçay, Erol; Raab, Ted K.; Dirzo, Rodolfo; Gordon, Deborah M.

    2013-01-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism. PMID:24223521

  20. Water stress strengthens mutualism among ants, trees, and scale insects.

    Science.gov (United States)

    Pringle, Elizabeth G; Akçay, Erol; Raab, Ted K; Dirzo, Rodolfo; Gordon, Deborah M

    2013-11-01

    Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant-plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners' investments in a widespread ant-plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the ants with sugars, and the ants provide better defense of the carbon-producing leaves. Under water stress, the trees have smaller carbon pools. A model of the carbon trade-offs for the mutualistic partners shows that the observed strategies can arise from the carbon costs of rare but extreme events of herbivory in the rainy season. Thus, water limitation, together with the risk of herbivory, increases the strength of a carbon-based mutualism.

  1. Comparisons of Photosynthetic Responses of Xanthium strumarium and Helianthus annuus to Chronic and Acute Water Stress in Sun and Shade 1

    Science.gov (United States)

    Ben, Gui-Ying; Osmond, C. Barry; Sharkey, Thomas D.

    1987-01-01

    We have examined the effects of mild, chronic water stress and acute water stress on two water stress sensitive plants, Xanthium strumarium and Helianthus annuus. Using a combination of the leaf disc O2 electrode to measure the light responses of photosynthesis and 77 K fluorescence to monitor damage to the primary photochemistry, we have found the following: (a) The CO2 saturated rate of photosynthesis at high light is the most water stress sensitive parameter measured. (b) The apparent quantum yield (moles O2 per mole photons) was slightly, if at all, affected by mild water stress (>−1.5 megapascals). (c) Severe water stress (<−1.5 megapascals) reduced the quantum yield of photosynthesis regardless of whether the stress was applied in sun or shade. The light independent reduction of quantum yield was not associated with a reduction in 77 K fluorescence (Fv/Fm) indicating that the quantum yield reduction was not the result of damage to primary photochemistry. (d) The diel fluctuation in 77 K fluorescence seen in sun-exposed control leaves was greatly exaggerated in water stressed leaves because of enhanced decline in 77 K fluorescence in the morning. The rate of recovery was similar in both control and water stressed leaves. Shaded leaves showed no change in 77 K fluorescence regardless of whether water stress was imposed or not. (e) The water stress sensitive plants used in these experiments did not recover from acute water stress severe enough to reduce the quantum yield or chronic water stress which lasted long enough that light dependent damage to primary photochemistry occurred. PMID:16665465

  2. Movement of Abscisic Acid into the Apoplast in Response to Water Stress in Xanthium strumarium L.

    Science.gov (United States)

    Cornish, K; Zeevaart, J A

    1985-07-01

    The effect of water stress on the redistribution of abcisic acid (ABA) in mature leaves of Xanthium strumarium L. was investigated using a pressure dehydration technique. In both turgid and stressed leaves, the ABA in the xylem exudate, the ;apoplastic' ABA, increased before ;bulk leaf' stress-induced ABA accumulation began. In the initially turgid leaves, the ABA level remained constant in both the apoplast and the leaf as a whole until wilting symptoms appeared. Following turgor loss, sufficient quantities of ABA moved into the apoplast to stimulate stomatal closure. Thus, the initial increase of apoplastic ABA may be relevant to the rapid stomatal closure seen in stressed leaves before their bulk leaf ABA levels rise.Following recovery from water stress, elevated levels of ABA remained in the apoplast after the bulk leaf contents had returned to their prestress values. This apoplastic ABA may retard stomatal reopening during the initial recovery period.

  3. Barley HvPAPhy_a as transgene provides high and stable phytase activities in mature barley straw and in grains

    DEFF Research Database (Denmark)

    Holme, Inger; Dionisio, Giuseppe; Madsen, Claus Krogh

    2017-01-01

    The phytase purple acid phosphatase (HvPAPhy_a) expressed during barley seed development was evaluated as transgene for overexpression in barley. The phytase was expressed constitutively driven by the cauliflower mosaic virus 35S-promoter, and the phytase activity was measured in the mature grains......, the green leaves and in the dry mature vegetative plant parts left after harvest of the grains. The T2-generation of HvPAPhy_a transformed barley showed phytase activity increases up to 19-fold (29 000 phytase units (FTU) per kg in mature grains). Moreover, also in green leaves and mature dry straw, phytase...... activities were increased significantly by 110-fold (52 000 FTU/kg) and 57-fold (51 000 FTU/kg), respectively. The HvPAPhy_a-transformed barley plants with high phytase activities possess triple potential utilities for the improvement of phosphate bioavailability. First of all, the utilization of the mature...

  4. Expression of NCED gene in colored cotton genotypes subjected to water stress

    Directory of Open Access Journals (Sweden)

    Alexandre M. S. de Souza

    Full Text Available ABSTRACT Considering that the NCED gene acts on the biosynthetic cascade of ABA, a hormone involved in the functioning of stomata and consequently in the regulation of transpiration, the aim of this research was to analyze the expression of this gene in colored cotton genotypes subjected to water stress at the beginning of plant growth. Four colored cotton genotypes were used, subjected to two managements, with and without water stress, beginning the treatments when the blade of the first true leaves reached an area that allowed the evaluation of gas exchange. For the studies of the expression of the NCED gene, via RT-qPCR, leaves were collected on three distinct dates: at 4 and 6 days of water stress, and after the plants regained their turgor. The differential expression of NCED was found in all genotypes, with higher levels of expression related to six days of water stress. When the stomatal conductance was around 25%, there was overexpression in the genotype CNPA 2009.13, followed by CNPA 2009.6, BRS SAFIRA and CNPA 2009.11, confirming the data obtained in the semi-quantitative RT-PCR. The NCED gene is involved in the response to water stress in the vegetative phase of colored cotton.

  5. Water stress mitigates the negative effects of ozone on photosynthesis and biomass in poplar plants.

    Science.gov (United States)

    Gao, Feng; Catalayud, Vicent; Paoletti, Elena; Hoshika, Yasutomo; Feng, Zhaozhong

    2017-11-01

    Tropospheric ozone (O 3 ) pollution frequently overlaps with drought episodes but the combined effects are not yet understood. We investigated the physiological and biomass responses of an O 3 sensitive hybrid poplar clone ('546') under three O 3 levels (charcoal-filtered ambient air, non-filtered ambient air (NF), and NF plus 40 ppb) and two watering regimes (well-watered (WW) and reduced watering (RW), i.e. 40% irrigation) for one growing season. Water stress increased chlorophyll and carotenoid contents, protecting leaves from pigment degradation by O 3 . Impairment of photosynthesis by O 3 was also reduced by stomatal closure due to water stress, which preserved light-saturated CO 2 assimilation rate, and the maximum carboxylation efficiency. Water stress increased water use efficiency of the leaves while O 3 decreased it, showing significant interactions. Effects were more evident in older leaves than in younger leaves. Water stress reduced biomass production, but the negative effects of O 3 were less in RW than in WW for total biomass per plant. A stomatal O 3 flux-based dose-response relationship was parameterized considering water stress effects, which explained biomass losses much better than a concentration-based approach. The O 3 critical level of Phytotoxic Ozone Dose over a threshold of 7 nmol O 3 .m -2 .s -1 (POD 7 ) for a 4% biomass loss in this poplar clone under different water regimes was 4.1 mmol m -2 . Our results suggest that current O 3 levels in most parts of China threaten poplar growth and that interaction with water availability is a key factor for O 3 risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. ALTERATIONS IN BARLEY PROTEOME UPON FUNGAL INFECTION AND TRICYCLAZOLE TREATMENT

    Directory of Open Access Journals (Sweden)

    Manoj Kumar a,b

    2017-04-01

    Full Text Available The barley proteome was investigated upon fungal infection and subsequent treatment by tricyclazole (TCZ, which is known to have applications in spot blotch disease management in barley.Significantly enhanced chlorophyll content was recorded in TCZ treated plants. The disease severity was significantly reduced after TCZ application in pathogen inoculated plants by reducing the appressoria formation at infection site in barley leaves. Two-dimensional gel electrophoresis (2-DE revealed the expression profile of proteins from (I control plants (healthy barley leaves; application with sterile water,(II plants after foliar application of TCZ (100 µg/ml, (III plants inoculated with B. sorokiniana and (IV plants treated with TCZ (72 h after B. sorokiniana inoculation. A set of 33 proteins expressed differentially after TCZ treatment. Out of this 19 had known functions, while others were unknown or hypothetical proteins. These differentially expressed proteins were related to redox-activity and gene expression, electron transfer,cell division and chromosome partitioning, cell envelop biogenesis, energy metabolism and conversion, respiration and pathogenesis related functions in the barley plants. The study provides a platform and documents the proteins that might be involved in disease management in barley following TCZ application. It is expected that the study will provide boost in understanding proteome regulation upon fungal infection and subsequent anti-fungal treatment and will attract researchers for further validation leading to better pest management.

  7. Use of crop water stress index for monitoring water stress in some sinanthropic plant species

    Directory of Open Access Journals (Sweden)

    Marinela Roxana ROŞESCU

    2010-11-01

    Full Text Available The water stress indicator (crop water stress index, CWSI is a measure of the transpiration rate of a plant, influenced by the leaf and air temperature difference from the plant’s vicinity and the air pressure deficit of the water vapors from the atmosphere. The experiments were realized in July-August 2008 and 2009 for six species in the cities Pitesti, Mioveni and Maracineni: Cichorium intybus L., Conyza canadensis (L. Cronq., Erigeron annuus L. (Pers., Lactuca serriola Torn., Polygonum aviculare L. and Echinochloa crus-galli (L. Beauv. For those species we calculated the CWSI to estimate the water stress on the selected plants in the urban environment conditions. The analyzed species were exposed to a less accentuated water stress while vegetating in the soil and to a more intense one they were grown in the asphalt cracks. Cichorium intybus had the smallest CWSI value (0.26 while Lactuca serriola the highest one (0.44.

  8. Hydraulic failure defines the recovery and point of death in water-stressed conifers.

    Science.gov (United States)

    Brodribb, Tim J; Cochard, Hervé

    2009-01-01

    This study combines existing hydraulic principles with recently developed methods for probing leaf hydraulic function to determine whether xylem physiology can explain the dynamic response of gas exchange both during drought and in the recovery phase after rewatering. Four conifer species from wet and dry forests were exposed to a range of water stresses by withholding water and then rewatering to observe the recovery process. During both phases midday transpiration and leaf water potential (Psileaf) were monitored. Stomatal responses to Psileaf were established for each species and these relationships used to evaluate whether the recovery of gas exchange after drought was limited by postembolism hydraulic repair in leaves. Furthermore, the timing of gas-exchange recovery was used to determine the maximum survivable water stress for each species and this index compared with data for both leaf and stem vulnerability to water-stress-induced dysfunction measured for each species. Recovery of gas exchange after water stress took between 1 and >100 d and during this period all species showed strong 1:1 conformity to a combined hydraulic-stomatal limitation model (r2 = 0.70 across all plants). Gas-exchange recovery time showed two distinct phases, a rapid overnight recovery in plants stressed to 50% loss of Kleaf. Maximum recoverable water stress (Psimin) corresponded to a 95% loss of Kleaf. Thus, we conclude that xylem hydraulics represents a direct limit to the drought tolerance of these conifer species.

  9. Water stress drastically reduces root growth and inulin yield in Cichorium intybus (var. sativum) independently of photosynthesis

    Science.gov (United States)

    Vandoorne, B.; Mathieu, A.-S.; Van den Ende, W.; Vergauwen, R.; Périlleux, C.; Javaux, M.; Lutts, S.

    2012-01-01

    Root chicory (Cichorium intybus var. sativum) is a cash crop cultivated for inulin production in Western Europe. This plant can be exposed to severe water stress during the last 3 months of its 6-month growing period. The aim of this study was to quantify the effect of a progressive decline in water availability on plant growth, photosynthesis, and sugar metabolism and to determine its impact on inulin production. Water stress drastically decreased fresh and dry root weight, leaf number, total leaf area, and stomatal conductance. Stressed plants, however, increased their water-use efficiency and leaf soluble sugar concentration, decreased the shoot-to-root ratio and lowered their osmotic potential. Despite a decrease in photosynthetic pigments, the photosynthesis light phase remained unaffected under water stress. Water stress increased sucrose phosphate synthase activity in the leaves but not in the roots. Water stress inhibited sucrose:sucrose 1-fructosyltransferase and fructan:fructan 1 fructosyltransferase after 19 weeks of culture and slightly increased fructan 1-exohydrolase activity. The root inulin concentration, expressed on a dry-weight basis, and the mean degree of polymerization of the inulin chain remained unaffected by water stress. Root chicory displayed resistance to water stress, but that resistance was obtained at the expense of growth, which in turn led to a significant decrease in inulin production. PMID:22577185

  10. Water stress induced changes in antioxidant enzymes, membrane ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... membrane stability index occurred under water stress. Accession 320 ... yielding wheat varieties for areas affected by water stress. (Mujtaba ...... Peroxidase activity in golden delicious apples as a ... Food Chem. 24: 200-201.

  11. Physiological basis of barley yield under near optimal and stress conditions

    Directory of Open Access Journals (Sweden)

    Pržulj Novo

    2004-01-01

    Full Text Available Average barley yield fall below its potential due to incidence of stresses. Water stress is the main environmental factor limiting yield. The component a priori more sensitive to most stresses is the amount of radiation absorbed. The effect of stresses influence on the total amount of radiation absorbed by barley crop during its vegetation and the photosynthetic efficiency of radiation conversion. Growth inhibition is accompanied by reductions in leaf and cell wall extensibility. Grain yield under drought conditions is source limited. Supply of assimilates to the developing inflorescence plays a critical role in establishing final grain number and grain size. Grain weight is negatively affected by drought, high temperature, and any other factors that may reduce grain filling duration and grain filling rate. Awns and glaucousness confer better performance of barley under drought stress conditions. Barley responds with an increased accumulation of a number of proteins when subjected to different stress inducing cell dehydration. Screening techniques that are able to identify desirable genotypes based on the evaluation of physiological traits related to stress evasion and stress resistance maybe useful in breeding barley for resistance to stress, particularly drought stress. Crop management and breeding can reduce the incidence of stress on yield. The effect of these practices is sustained by an understanding of their physiology. In this paper the physiological basis of the processes determining barley yield and the incidence of stresses on photosynthetic metabolism that determine grain yield of barley is discussed. .

  12. Identification of genes involved in a water stress response in timothy and mapping of orthologous loci in perennial ryegrass

    DEFF Research Database (Denmark)

    Jonavičienė, Kristina; Studer, Bruno; Asp, Torben

    2012-01-01

    In order to characterize the response of selected grasses to water stress, relative water content (RWC) in leaves and quantum efficiency of photosystem 2 (Fv/Fm) were measured in Phleum pratense L., P. bertolonii DC. and P. phleoides H. Karst. during 6 d of water stress. The results indicated...... differential responses to water stress among the three Phleum species with higher water deficit sensitivity of P. pratense and P. bertolonii than that of P. phleoides. The cDNA-amplified fragment length polymorphism (cDNA-AFLP) technique was applied to identify differentially expressed genes responding...... to water stress in P. pratense. Cloned and sequenced differentially expressed fragments (DEFs) were used for primer design in order to identify orthologous genes in Lolium perenne L. Twelve genes orthologous to P. pratense DEFs were mapped in the L. perenne mapping population VrnA based on a high...

  13. Assessing corn water stress using spectral reflectance

    Science.gov (United States)

    Mefford, Brenna S.

    Multiple remote sensing techniques have been developed to identify crop water stress, but some methods may be difficult for farmers to apply. Unlike most techniques, shortwave vegetation indices can be calculated using satellite, aerial, or ground imagery from the green (525-600 nm), red (625-700 nm), and near infrared (750-900 nm) spectral bands. If vegetation indices can be used to monitor crop water stress, growers could use this information as a quick low-cost guideline for irrigation management, thus helping save water by preventing over irrigating. This study occurred in the 2013 growing season near Greeley, CO, where pressurized drip irrigation was used to irrigate twelve corn ( Zea mays L.) treatments of varying water deficit. Multispectral data was collected and four different vegetation indices were evaluated: Normalized Difference Vegetation Index (NDVI), Optimized Soil-Adjusted Vegetation Index (OSAVI), Green Normalized Difference Vegetation Index (GNDVI), and the Wide Dynamic Range Vegetation Index (WDRVI). The four vegetation indices were compared to corn water stress as indicated by the stress coefficient (Ks) and water deficit in the root zone, calculated by using a water balance that monitors crop evapotranspiration (ET), irrigation events, precipitation events, and deep percolation. ET for the water balance was calculated using two different methods for comparison purposes: (1) calculation of the stress coefficient (Ks) using FAO-56 standard procedures; (2) use of canopy temperature ratio (Tc ratio) of a stressed crop to a non-stressed crop to calculate Ks. It was found that obtaining Ks from Tc ratio is a viable option, and requires less data to obtain than Ks from FAO-56. In order to compare the indices to Ks, vegetation ratios were developed in the process of normalization. Vegetation ratios are defined as the non-stressed vegetation index divided by the stressed vegetation index. Results showed that vegetation ratios were sensitive to water

  14. Nondestructive detection of water stress in tomato [Lycopersicon esculentum] plants using microwave sensing, 2

    International Nuclear Information System (INIS)

    Shimomachi, T.; Takemasa, T.; Kurata, K.; Takakura, T.

    2004-01-01

    The physiological accommodation response to environmental stress of a plant can induce changes in physiological and physical conditions of the plant. These changes influence the dielectric properties of the plant, which can be detected by measuring microwave complex dielectric properties of plant materials such as leaves and stems. The objective of this research was to detect these responses of plants to water deficiency stress nondestructively. The complex dielectric properties of tomato leaves during water stress were measured with an Open-ended Coaxial Probe from 0.3 to 3 GHz, as well as changes in gravimetric moisture, photosynthetic rate, stomatal conductance and water potential which reflect the physiological condition of the plants. Experimental results showed that the complex permittivity (both permittivity and loss factor) of tomato leaves increased during water stress. Of the parameters measured the highest correlation was observed between complex permittivity and water potential. In order to confirm these results, control and water deficient tomato leaves were crushed, and the complex permittivity was measured and compared. The results showed quite similar tendencies compared with the results from the nondestructive microwave measurements. A physiochemical model to describe the complex permittivity of crushed non-stressed and stressed tomato leaves was constructed with pure water, pulp, glycine, and KN03, and the complex dielectric measurements of crushed tomato leaves were reproduced quite accurately from 0.3 to 3 GHz

  15. Effect of microwave freeze drying on quality and energy supply in drying of barley grass.

    Science.gov (United States)

    Cao, Xiaohuang; Zhang, Min; Mujumdar, Arun S; Zhong, Qifeng; Wang, Zhushang

    2018-03-01

    Young barley grass leaves are well-known for containing the antioxidant substances flavonoid and chlorophyll. However, low product quality and energy efficiency exist with respect to the dehydration of barley grass leaves. To improve energy supply and the quality of barley grass, microwave heating instead of contact heat was applied for the freeze drying of barley grass at a pilot scale at 1, 1.5 and 2 W g -1 , respectively; After drying, energy supply and quality parameters of color, moisture content, chlorophyll, flavonoids, odors of dried barley grass were determined to evaluate the feasibility of the study. Microwave freeze drying (MFD) allowed a low energy supply and high contents of chlorophyll and flavonoids. A lightness value of 60.0, a green value of -11.5 and an energy supply of 0.61 kW h -1  g -1 were observed in 1.5 W g -1 MFD; whereas drying time (7 h) decreased by 42% compared to contact heating. Maximum content of flavonoid and chlorophyll was 11.7 and 12.8 g kg -1 barley grass. Microwave heating leads to an odor change larger than that for contact heating observed for the freeze drying of barley grass. MFD retains chlorophyll and flavonoids, as well as colors and odors of samples, and also decreases energy consumption in the freeze drying of barley grass. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. Estimating water stressed dwarf green bean pigment concentration through hyperspectral indices

    International Nuclear Information System (INIS)

    Koksal, E.S.; Ustrun, H.; Ozcan, H.; Gunturk, A.

    2010-01-01

    In this study, the relationship between leaf pigment concentration (analyzed in the laboratory) and four spectral indexes (measured in the field) was investigated. For this purpose, field experiments consisting of six different irrigation treatments were conducted with dwarf green beans during 2005 growing season. Based on spectral data, spectral indexes were plotted against pigment concentration. Results showed that under water stress, the chlorophyll and carotene contents of green bean leaves rose. According to linear regression analysis between spectral indexes and pigment contents, the Normalized Difference Pigment Chlorophyll Index (NPCI) and Normalized Difference Vegetation Index (NDVI) had the highest correlations with the chlorophyll (a, b and total), and carotene content of leaves. (author)

  17. Movement of Abscisic Acid into the Apoplast in Response to Water Stress in Xanthium strumarium L. 1

    Science.gov (United States)

    Cornish, Katrina; Zeevaart, Jan A. D.

    1985-01-01

    The effect of water stress on the redistribution of abcisic acid (ABA) in mature leaves of Xanthium strumarium L. was investigated using a pressure dehydration technique. In both turgid and stressed leaves, the ABA in the xylem exudate, the `apoplastic' ABA, increased before `bulk leaf' stress-induced ABA accumulation began. In the initially turgid leaves, the ABA level remained constant in both the apoplast and the leaf as a whole until wilting symptoms appeared. Following turgor loss, sufficient quantities of ABA moved into the apoplast to stimulate stomatal closure. Thus, the initial increase of apoplastic ABA may be relevant to the rapid stomatal closure seen in stressed leaves before their bulk leaf ABA levels rise. Following recovery from water stress, elevated levels of ABA remained in the apoplast after the bulk leaf contents had returned to their prestress values. This apoplastic ABA may retard stomatal reopening during the initial recovery period. PMID:16664294

  18. Construction of barley consensus map showing chromosomal ...

    African Journals Online (AJOL)

    In the past, it has been difficult to accurately determine the location of many types of barley molecular markers due to the lack of commonality between international barley linkage maps. In this study, a consensus map of barley was constructed from five different maps (OWB, VxHs, KxM, barley consensus 2 and barley ...

  19. Abscisic Acid Metabolism in Relation to Water Stress and Leaf Age in Xanthium strumarium1

    Science.gov (United States)

    Cornish, Katrina; Zeevaart, Jan A.D.

    1984-01-01

    Intact plants of Xanthium strumarium L. were subjected to a water stress-recovery cycle. As the stress took effect, leaf growth ceased and stomatal resistance increased. The mature leaves then wilted, followed by the half expanded ones. Water, solute, and pressure potentials fell steadily in all leaves during the rest of the stress period. After 3 days, the young leaves lost turgor and the plants were rewatered. All the leaves rapidly regained turgor and the younger ones recommenced elongation. Stomatal resistance declined, but several days elapsed before pre-stress values were attained. Abscisic acid (ABA) and phaseic acid (PA) levels rose in all the leaves after the mature ones wilted. ABA-glucose ester (ABA-GE) levels increased to a lesser extent, and the young leaves contained little of this conjugate. PA leveled off in the older leaves during the last 24 hours of stress, and ABA levels declined slightly. The young leaves accumulated ABA and PA throughout the stress period and during the 14-hour period immediately following rewatering. The ABA and PA contents, expressed per unit dry weight, were highest in the young leaves. Upon rewatering, large quantities of PA appeared in the mature leaves as ABA levels fell to the pre-stress level within 14 hours. In the half expanded and young leaves, it took several days to reach pre-stress ABA values. ABA-GE synthesis ceased in the mature leaves, once the stress was relieved, but continued in the half expanded and young leaves for 2 days. Mature leaves, when detached and stressed, accumulated an amount of ABA similar to that in leaves on the intact plant. In contrast, detached and stressed young leaves produced little ABA. Detached mature leaves, and to a lesser extent the half expanded ones, rapidly catabolized ABA to PA and ABA-GE, but the young leaves did not. Studies with radioactive (±)-ABA indicated that in young leaves the conversion of ABA to PA took place at a much lower rate than in mature ones. Leaves of all

  20. Abscisic Acid Metabolism in Relation to Water Stress and Leaf Age in Xanthium strumarium.

    Science.gov (United States)

    Cornish, K; Zeevaart, J A

    1984-12-01

    Intact plants of Xanthium strumarium L. were subjected to a water stress-recovery cycle. As the stress took effect, leaf growth ceased and stomatal resistance increased. The mature leaves then wilted, followed by the half expanded ones. Water, solute, and pressure potentials fell steadily in all leaves during the rest of the stress period. After 3 days, the young leaves lost turgor and the plants were rewatered. All the leaves rapidly regained turgor and the younger ones recommenced elongation. Stomatal resistance declined, but several days elapsed before pre-stress values were attained.Abscisic acid (ABA) and phaseic acid (PA) levels rose in all the leaves after the mature ones wilted. ABA-glucose ester (ABA-GE) levels increased to a lesser extent, and the young leaves contained little of this conjugate. PA leveled off in the older leaves during the last 24 hours of stress, and ABA levels declined slightly. The young leaves accumulated ABA and PA throughout the stress period and during the 14-hour period immediately following rewatering. The ABA and PA contents, expressed per unit dry weight, were highest in the young leaves. Upon rewatering, large quantities of PA appeared in the mature leaves as ABA levels fell to the pre-stress level within 14 hours. In the half expanded and young leaves, it took several days to reach pre-stress ABA values. ABA-GE synthesis ceased in the mature leaves, once the stress was relieved, but continued in the half expanded and young leaves for 2 days.Mature leaves, when detached and stressed, accumulated an amount of ABA similar to that in leaves on the intact plant. In contrast, detached and stressed young leaves produced little ABA. Detached mature leaves, and to a lesser extent the half expanded ones, rapidly catabolized ABA to PA and ABA-GE, but the young leaves did not. Studies with radioactive (+/-)-ABA indicated that in young leaves the conversion of ABA to PA took place at a much lower rate than in mature ones. Leaves of all

  1. Malting barley BRS Borema

    Directory of Open Access Journals (Sweden)

    Euclydes Minella

    2006-01-01

    Full Text Available BRS Borema is an early maturing, two-rowed spring barley registered in 2003 for commercial production inSouthern Brazil, bred by Embrapa Trigo. It combines good yield potential with superior malting quality and a reasonable levelof disease (net blotch, powdery mildew, leaf rust resistance. It is well-adapted to all major production regions of maltingbarley in Brazil.

  2. Rootstock alleviates PEG-induced water stress in grafted pepper seedlings: physiological responses.

    Science.gov (United States)

    Penella, Consuelo; Nebauer, Sergio G; Bautista, Alberto San; López-Galarza, Salvador; Calatayud, Ángeles

    2014-06-15

    Recent studies have shown that tolerance to abiotic stress, including water stress, is improved by grafting. In a previous work, we took advantage of the natural variability of Capsicum spp. and selected accessions tolerant and sensitive to water stress as rootstocks. The behavior of commercial cultivar 'Verset' seedlings grafted onto the selected rootstocks at two levels of water stress provoked by adding 3.5 and 7% PEG (polyethylene glycol) was examined over 14 days. The objective was to identify the physiological traits responsible for the tolerance provided by the rootstock in order to determine if the tolerance is based on the maintenance of the water relations under water stress or through the activation of protective mechanisms. To achieve this goal, various physiological parameters were measured, including: water relations; proline accumulation; gas exchange; chlorophyll fluorescence; nitrate reductase activity; and antioxidant capacity. Our results indicate that the effect of water stress on the measured parameters depends on the duration and intensity of the stress level, as well as the rootstock used. Under control conditions (0% PEG) all plant combinations showed similar values for all measured parameters. In general terms, PEG provoked a strong decrease in the gas exchange parameters in the cultivar grafted onto the sensitive accessions, as also observed in the ungrafted plants. This effect was related to lower relative water content in the plants, provoked by an inefficient osmotic adjustment that was dependent on reduced proline accumulation. At the end of the experiment, chronic photoinhibition was observed in these plants. However, the plants grafted onto the tolerant rootstocks, despite the reduction in photosynthetic rate, maintained the protective capacity of the photosynthetic machinery mediated by osmotic adjustment (based on higher proline content). In addition, water stress limited uptake and further NO3(-) transfer to the leaves. Increased

  3. Water-Stressed Loquat Trees Need More Time and Heat to Ripen Their Fruits

    Directory of Open Access Journals (Sweden)

    Julián Cuevas

    2018-06-01

    Full Text Available To determine if water-stressed trees need more time and heat to mature their fruits, we compared chronological and thermal time from bloom to harvest among control fully-irrigated ‘Algerie’ loquat trees and trees suffering prior-to-bloom deficit irrigation (DI. Heat requirement calculation was performed using the double sine method with a lower threshold temperature of 3 °C. The results show that the greater the blooming advancement achieved by DI, the longer the period to mature the fruits. Such a pattern indicates that the longer duration for bloom-harvest period under DI is due to a displacement of the reproductive phenology to cooler dates. However, some effects of DI on heat requirements for ripening persist, indicating a slower fruit development in some, but not all, DI treatments. The differences in fruit development rate between fully-irrigated and water-stressed trees were established during the phase of rapid fruit growth. The comparison of water stress effects on sink (flower size and seed number and source (leaf number and size, gas exchange and mineral and carbohydrate nutrition of DI treatments seems to indicate that the amount of stored reserves in the leaves to sustain early fruit development is the most plausible reason behind the increase in thermal time between bloom and harvest in water-stressed loquats.

  4. Dynamic Allocation of Sugars in Barley

    Science.gov (United States)

    Cumberbatch, L. C.; Crowell, A. S.; Fallin, B. A.; Howell, C. R.; Reid, C. D.; Weisenberger, A. G.; Lee, S. J.; McKisson, J. E.

    2014-03-01

    Allocation of carbon and nitrogen is a key factor for plant productivity. Measurements are carried out by tracing 11C-tagged sugars using positron emission tomography and coincidence counting. We study the mechanisms of carbon allocation and transport from carbohydrate sources (leaves) to sinks (stem, shoot, roots) under various environmental conditions such as soil nutrient levels and atmospheric CO2 concentration. The data are analyzed using a transfer function analysis technique to model transport and allocation in barley plants. The experimental technique will be described and preliminary results presented. This work was supported in part by USDOE Grant No. DE-FG02-97-ER41033 and DE-SC0005057.

  5. Physiological responses in barley to applications of lanthanum

    International Nuclear Information System (INIS)

    Reddy, N.; Maheswaran, J.; Peverill, K.; Meehan, B.

    1998-01-01

    Full text: Chinese research and glasshouse investigations carried out in Victoria by the authors have shown that several plant species, when treated with Rare Earth Elements (REEs), retain greater amounts of moisture under water stressed conditions. The physiological adaptation of the plant to retain moisture in response to REE treatment however, has not been investigated. A glasshouse trial is currently in progress to study the physiological and agronomic responses of barley (cv. Schooner) grown in pots to application of lanthanum (0, 5 and 10 kg/ha), at a concentration of 0.05%, under well-watered (field capacity) and water-deficit (25 - 30% field capacity) conditions. Lanthanum was applied both directly to the soil and as a foliar spray. The physiological measurements include, photosynthetic rate, leaf water potential, osmotic potential, relative water content, stomatal conductance and water use efficiency. Measured agronomic parameters include plant height, tiller production, leaf area development, total grain weight, total biomass, root and shoot ratio and harvest index. Analysis of plant tissue for N, P, K, Ca, Mg, Zn and La to study the relationship between application of REE and nutrient uptake is also being carried out. The paper discusses physiological and agronomic changes in barley plants in response to treatment with lanthanum, under conditions of water stress

  6. Survival strategies of plants during water stress

    International Nuclear Information System (INIS)

    Scheuermann, R.; Stuhlfauth, T.; Sueltemeyer, D.; Fock, H.

    1989-01-01

    Fluorescence and gas exchange of bean, maize, sunflower and wooly foxglove were simultaneously measured at 250 μmol quanta/m 2 /s. Under severe water stresses conditions about 40% of the photochemical energy was converted to heat at PS II. This is interpreted as a protective mechanism against photoinhibitory damage when net CO 2 uptake is reduced by about 70%. After 14 CO 2 gas exchange, only in bean was a homogeneous distribution of radioactivity over the leaf observed. In all other plants we found a patchy distribution of regions with either an intensive or a reduced gas exchange. We conclude that CO 2 -recycling (photorespiration and reassimilation) behind closed stomata also contributed to energy dissipation under severe stress conditions

  7. Effects of water stress and inoculation with plant growth promoting rhizobacteria (PGPR on antioxidant status and photosynthetic pigments in basil (Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    Mostafa Heidari

    2012-01-01

    Full Text Available Effects of water stress and inoculation with plant growth promoting rhizobacteria (PGPR on antioxidant activity and photosynthetic pigments were studied in basil plants. A field experiment was conducted at the University of Zabol in Iran during 2010 growing season. The experiment laid out as split plot based on randomized complete block design with three replications. Three levels of water stress W1 = 80 (control, W2 = 60 and W3 = 40% of the field capacity (FC as main plots and four levels of bacterial species consisting of S1 = Pseudomonades sp., S2 = Bacillus lentus, S3 = Azospirillum brasilens, S4 = combination of three bacterial species and S5 = control (without use of bacterial as sub plots. The results revealed that water stress caused a significant change in the antioxidant activity. The highest concentration CAT and GPX activity were in W3 treatments. By increasing water stress from control to W3, chlorophyll content in leaves was increased but Fv/Fm and APX activity decreased. Application of rhizobacteria under water stress improved the antioxidant and photosynthetic pigments in basil plants. S1 = Pseudomonades sp. under water stress, significantly increased the CAT enzyme activity, but the highest GPX and APX activity and chlorophyll content in leaves under water stress were in S4 = combination of three bacterial species.

  8. Spectral reflectance relationships to leaf water stress

    Science.gov (United States)

    Ripple, William J.

    1986-01-01

    Spectral reflectance data were collected from detached snapbean leaves in the laboratory with a multiband radiometer. Four experiments were designed to study the spectral response resulting from changes in leaf cover, relative water content of leaves, and leaf water potential. Spectral regions included in the analysis were red (630-690 nm), NIR (760-900 nm), and mid-IR (2.08-2.35 microns). The red and mid-IR bands showed sensitivity to changes in both leaf cover and relative water content of leaves. The NIR was only highly sensitive to changes in leaf cover. Results provided evidence that mid-IR reflectance was governed primarily by leaf moisture content, although soil reflectance was an important factor when leaf cover was less than 100 percent. High correlations between leaf water potentials and reflectance were attributed to covariances with relative water content of leaves and leaf cover.

  9. The enhanced callose deposition in barley with ml-o powdery mildew resistance genes

    DEFF Research Database (Denmark)

    Skou, Jens-Peder

    1985-01-01

    Carborundum treatment of barley leaves induced a callose deposition which was detected as diffuse blotches in the epidermal cells of susceptible barleys and as deeply stained tracks along the scratches in barleys with the ml-o powdery mildew resistance gene. Subsequent inoculation with powdery...... mildew resulted in appositions that enlarged inversely to their size in the respective varieties when inoculated without carborundum treatment. Aphids sucking the leaves resulted in rows of callose containing spots along the anticlinal cell walls. The spots were larger in the ml-o mutant than...... in the mother variety. Callose was deposited in connection with the pleiotropic necrotic spotting in barleys with the ml-o gene. Modification of the necrotic spotting by crossing the ml-o gene into other gene backgrounds did not result in any change in the size of appositions upon inoculation with powdery...

  10. Water stress induces overexpression of superoxide dismutases that ...

    African Journals Online (AJOL)

    Water stress is known to induce active oxygen species in plants. The accumulation of these harmful species must be prevented by plants as rapidly as possible to maintain growth and productivity. The aim of this study was to determine the effect of water stress on superoxide dismutase isozymes (SOD, EC 1.15.1.1.) in two ...

  11. Critical water stress levels in Pinus patula seedlings and their ...

    African Journals Online (AJOL)

    Critical water stress levels in Pinus patula seedlings and their relation to measures of seedling morphology. ... Southern Forests: a Journal of Forest Science ... A pot trial was implemented to determine the effect of soil water stress following transplanting on shoot water potential and stomatal conductance of Pinus patula ...

  12. Fluorescência da clorofila a em folhas de tangerineira 'Ponkan' e limeira ácida 'Tahiti' submetidas ao estresse hídrico Chlorophyll a fluorescence in leaves of 'Ponkan' mandarin and the 'Tahiti' acid lime submitted to water stress

    Directory of Open Access Journals (Sweden)

    Maria do Céu Monteiro da Cruz

    2009-09-01

    Full Text Available O trabalho foi realizado com o objetivo de avaliar o estresse causado por deficiência hídrica para induzir o florescimento sobre a fluorescência da clorofila a em tangerineira 'Ponkan' e limeira ácida 'Tahiti'. As plantas foram enxertadas sobre o limoeiro 'Cravo', conduzidas em câmara de crescimento sob condições controladas. O estresse causado pela deficiência hídrica submetido à tangerineira 'Ponkan' e à limeira ácida 'Tahiti' reduziu a eficiência quântica potencial do fotossistema II (Fv/Fm. Após a irrigação, as plantas apresentaram valores dos parâmetros de fluorescência similares àqueles verificados antes do estresse submetido por deficiência hídrica.The research was carried out with the aim to evaluate the stress caused by water deficiency on a chlorophyll a fluorescence in 'Ponkan' mandarin and 'Tahiti' acid lime plants. The plants were grafted on Rangpur lime submitted to water stress in growth chamber under controlled conditions for induce the flowering. the stress caused by water deficiency submitted in plants of mandarin 'Ponkan' and 'Tahiti' lime decreased the potential quantum efficiency of photosystem II (Fv/Fm. After the irrigation the plants showed fluorescence parameters values similar to those prior to stress submitted by water deficiency.

  13. Barley HvPAPhy_a as transgene provides high and stable phytase activities in mature barley straw and in grains.

    Science.gov (United States)

    Holme, Inger Baeksted; Dionisio, Giuseppe; Madsen, Claus Krogh; Brinch-Pedersen, Henrik

    2017-04-01

    The phytase purple acid phosphatase (HvPAPhy_a) expressed during barley seed development was evaluated as transgene for overexpression in barley. The phytase was expressed constitutively driven by the cauliflower mosaic virus 35S-promoter, and the phytase activity was measured in the mature grains, the green leaves and in the dry mature vegetative plant parts left after harvest of the grains. The T 2 -generation of HvPAPhy_a transformed barley showed phytase activity increases up to 19-fold (29 000 phytase units (FTU) per kg in mature grains). Moreover, also in green leaves and mature dry straw, phytase activities were increased significantly by 110-fold (52 000 FTU/kg) and 57-fold (51 000 FTU/kg), respectively. The HvPAPhy_a-transformed barley plants with high phytase activities possess triple potential utilities for the improvement of phosphate bioavailability. First of all, the utilization of the mature grains as feed to increase the release of bio-available phosphate and minerals bound to the phytate of the grains; secondly, the utilization of the powdered straw either directly or phytase extracted hereof as a supplement to high phytate feed or food; and finally, the use of the stubble to be ploughed into the soil for mobilizing phytate-bound phosphate for plant growth. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  14. Effect of Water Stress and Sulfur Fertilizer on Grain Yield, Chlorophyll and Nutrient Status of Black Cumin (Nigella Sativa L.

    Directory of Open Access Journals (Sweden)

    M. Heidari

    2011-04-01

    Full Text Available In order to study the effects of water stress and different amounts of sulfur fertilizer on grain yield, nutrient status and chlorophyll content in black cumin (Nigella sativa L. a field experiment as split plot design with three replications was conducted at Ghaen city in 2009. Treatments included three levels of irrigation after 50, 100 and 150 mm evaporation from Class A pan as main plot and four levels of sulfur fertilizer including 0, 75, 150 and 225 kg/ha from bentonite-sulfur source as sub-plot. Statistical analysis of the results showed that water stress has significant effect on grain yield and essential oil of black cumin. At the level of 150 mm evaporation from Class A pan, the grain yield decreased by 22.8% and essential oil by 27.6%. Application of 225 kg/ha sulfur fertilizer increased grain yield up to 7.2%. Water stress and sulfur fertilizer treatments had only significant effect on chlorophyll a content. However, water stress decreased chlorophyll a content, but sulfur fertilizer application up to 225 kg/ha increased the content of chlorophyll a. In this study, water stress decreased potassium content in black cumin leaves, but increased the sodium and calcium accumulation. Although application of sulfur fertilizer affected significantly the potassium and magnesium contents in shoots, but did not have significant effect on sodium and calcium contents.

  15. Genomic Prediction in Barley

    DEFF Research Database (Denmark)

    Edriss, Vahid; Cericola, Fabio; Jensen, Jens D

    2015-01-01

    to next generation. The main goal of this study was to see the potential of using genomic prediction in a commercial Barley breeding program. The data used in this study was from Nordic Seed company which is located in Denmark. Around 350 advanced lines were genotyped with 9K Barely chip from Illumina....... Traits used in this study were grain yield, plant height and heading date. Heading date is number days it takes after 1st June for plant to head. Heritabilities were 0.33, 0.44 and 0.48 for yield, height and heading, respectively for the average of nine plots. The GBLUP model was used for genomic...

  16. An Integrated Analysis of Changes in Water Stress in Europe

    DEFF Research Database (Denmark)

    Henrichs, T.; Lehner, B.; Alcamo, J.

    2002-01-01

    Future changes in water availability with climate change and changes in water use due to socio-economic development are to occur in parallel. In an integrated analysis we bring together these aspects of global change in a consistent manner, and analyse the water stress situation in Europe. We find...... that today high water stress exists in one-fifth of European river basin area. Under a scenario projection, increases in water use throughout Eastern Europe are accompanied by decreases in water availability in most of Southern Europe--combining these trends leads to a marked increase in water stress...

  17. Grafting improves cucumber water stress tolerance in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abdulaziz R. Al-Harbi

    2018-02-01

    Full Text Available Water scarcity is a major limiting factor for crop productivity in arid and semi-arid areas. Grafting elite commercial cultivars onto selected vigorous rootstocks is considered as a useful strategy to alleviate the impact of environmental stresses. This study aims to investigate the feasibility of using grafting to improve fruit yield and quality of cucumber under water stress conditions. Alosama F1 cucumber cultivar (Cucumis sativus L. was grafted onto Affyne (Cucumis sativus L. and Shintoza A90 (Cucurbitamaxima × C. moschata rootstocks. Non-grafted plants were used as control. All genotypes were grown under three surface drip irrigation regimes: 50%, 75% and 100% of the crop evapotranspiration (ETc, which represent high-water stress, moderate-water stress and non-water stress conditions, respectively. Yield and fruit quality traits were analyzed and assessed. In comparison to the non-grafted plants, the best grafting treatment under water stress was Alosama F1 grafted onto Shintoza A90 rootstock. It had an overall improved yield and fruit quality under water stress owing to an increase in the total fruit yield by 27%, from 4.815 kg plant−1 in non-grafted treatment to 6.149 kg plant−1 in grafted treatment under moderate -water stress, total soluble solid contents (13%, titratable acidity (39% and vitamin C (33%. The soil water contents were low in soil surface and increase gradually with soil depth, while salt distribution showed an adverse trend. The positive effects of grafting on plant growth, productivity, and water use efficiency support this strategy as an useful tool for improving water stress tolerance in greenhouse grown cucumber in Saudi Arabia.

  18. Grafting improves cucumber water stress tolerance in Saudi Arabia.

    Science.gov (United States)

    Al-Harbi, Abdulaziz R; Al-Omran, Abdulrasoul M; Alharbi, Khadiga

    2018-02-01

    Water scarcity is a major limiting factor for crop productivity in arid and semi-arid areas. Grafting elite commercial cultivars onto selected vigorous rootstocks is considered as a useful strategy to alleviate the impact of environmental stresses. This study aims to investigate the feasibility of using grafting to improve fruit yield and quality of cucumber under water stress conditions. Alosama F 1 cucumber cultivar ( Cucumis sativus L.) was grafted onto Affyne ( Cucumis sativus L.) and Shintoza A90 ( Cucurbitamaxima × C. moschata ) rootstocks. Non-grafted plants were used as control. All genotypes were grown under three surface drip irrigation regimes: 50%, 75% and 100% of the crop evapotranspiration (ETc), which represent high-water stress, moderate-water stress and non-water stress conditions, respectively. Yield and fruit quality traits were analyzed and assessed. In comparison to the non-grafted plants, the best grafting treatment under water stress was Alosama F 1 grafted onto Shintoza A90 rootstock. It had an overall improved yield and fruit quality under water stress owing to an increase in the total fruit yield by 27%, from 4.815 kg plant -1 in non-grafted treatment to 6.149 kg plant -1 in grafted treatment under moderate -water stress, total soluble solid contents (13%), titratable acidity (39%) and vitamin C (33%). The soil water contents were low in soil surface and increase gradually with soil depth, while salt distribution showed an adverse trend. The positive effects of grafting on plant growth, productivity, and water use efficiency support this strategy as an useful tool for improving water stress tolerance in greenhouse grown cucumber in Saudi Arabia.

  19. Enumeration of fungi in barley

    CSIR Research Space (South Africa)

    Rabie, CJ

    1997-04-01

    Full Text Available Estimation of fungal contamination of barley grain is important as certain fungi can proliferate during the malting process. The following factors which may affect the enumeration of fungi were evaluated: dilution versus direct plating, pre...

  20. Water stress-induced modifications of leaf hydraulic architecture in sunflower: co-ordination with gas exchange.

    Science.gov (United States)

    Nardini, Andrea; Salleo, Sebastiano

    2005-12-01

    The hydraulic architecture, water relationships, and gas exchange of leaves of sunflower plants, grown under different levels of water stress, were measured. Plants were either irrigated with tap water (controls) or with PEG600 solutions with osmotic potential of -0.4 and -0.8 MPa (PEG04 and PEG08 plants, respectively). Mature leaves were measured for hydraulic resistance (R(leaf)) before and after making several cuts across minor veins, thus getting the hydraulic resistance of the venation system (R(venation)). R(leaf) was nearly the same in controls and PEG04 plants but it was reduced by about 30% in PEG08 plants. On the contrary, R(venation) was lowest in controls and increased in PEG04 and PEG08 plants as a likely result of reduction in the diameter of the veins' conduits. As a consequence, the contribution of R(venation) to the overall R(leaf) markedly increased from controls to PEG08 plants. Leaf conductance to water vapour (g(L)) was highest in controls and significantly lower in PEG04 and PEG08 plants. Moreover, g(L) was correlated to R(venation) and to leaf water potential (psi(leaf)) with highly significant linear relationships. It is concluded that water stress has an important effect on the hydraulic construction of leaves. This, in turn, might prove to be a crucial factor in plant-water relationships and gas exchange under water stress conditions.

  1. Effects of water stress on irradiance acclimation of leaf traits in almond trees.

    Science.gov (United States)

    Egea, Gregorio; González-Real, María M; Baille, Alain; Nortes, Pedro A; Conesa, María R; Ruiz-Salleres, Isabel

    2012-04-01

    Photosynthetic acclimation to highly variable local irradiance within the tree crown plays a primary role in determining tree carbon uptake. This study explores the plasticity of leaf structural and physiological traits in response to the interactive effects of ontogeny, water stress and irradiance in adult almond trees that have been subjected to three water regimes (full irrigation, deficit irrigation and rain-fed) for a 3-year period (2006-08) in a semiarid climate. Leaf structural (dry mass per unit area, N and chlorophyll content) and photosynthetic (maximum net CO(2) assimilation, A(max), maximum stomatal conductance, g(s,max), and mesophyll conductance, g(m)) traits and stem-to-leaf hydraulic conductance (K(s-l)) were determined throughout the 2008 growing season in leaves of outer south-facing (S-leaves) and inner northwest-facing (NW-leaves) shoots. Leaf plasticity was quantified by means of an exposure adjustment coefficient (ε=1-X(NW)/X(S)) for each trait (X) of S- and NW-leaves. Photosynthetic traits and K(s-l) exhibited higher irradiance-elicited plasticity (higher ε) than structural traits in all treatments, with the highest and lowest plasticity being observed in the fully irrigated and rain-fed trees, respectively. Our results suggest that water stress modulates the irradiance-elicited plasticity of almond leaves through changes in crown architecture. Such changes lead to a more even distribution of within-crown irradiance, and hence of the photosynthetic capacity, as water stress intensifies. Ontogeny drove seasonal changes only in the ε of area- and mass-based N content and mass-based chlorophyll content, while no leaf age-dependent effect was observed on ε as regards the physiological traits. Our results also indicate that the irradiance-elicited plasticity of A(max) is mainly driven by changes in leaf dry mass per unit area, in g(m) and, most likely, in the partitioning of the leaf N content.

  2. Systems responses to progressive water stress in durum wheat.

    Directory of Open Access Journals (Sweden)

    Dimah Z Habash

    Full Text Available Durum wheat is susceptible to terminal drought which can greatly decrease grain yield. Breeding to improve crop yield is hampered by inadequate knowledge of how the physiological and metabolic changes caused by drought are related to gene expression. To gain better insight into mechanisms defining resistance to water stress we studied the physiological and transcriptome responses of three durum breeding lines varying for yield stability under drought. Parents of a mapping population (Lahn x Cham1 and a recombinant inbred line (RIL2219 showed lowered flag leaf relative water content, water potential and photosynthesis when subjected to controlled water stress time transient experiments over a six-day period. RIL2219 lost less water and showed constitutively higher stomatal conductance, photosynthesis, transpiration, abscisic acid content and enhanced osmotic adjustment at equivalent leaf water compared to parents, thus defining a physiological strategy for high yield stability under water stress. Parallel analysis of the flag leaf transcriptome under stress uncovered global trends of early changes in regulatory pathways, reconfiguration of primary and secondary metabolism and lowered expression of transcripts in photosynthesis in all three lines. Differences in the number of genes, magnitude and profile of their expression response were also established amongst the lines with a high number belonging to regulatory pathways. In addition, we documented a large number of genes showing constitutive differences in leaf transcript expression between the genotypes at control non-stress conditions. Principal Coordinates Analysis uncovered a high level of structure in the transcriptome response to water stress in each wheat line suggesting genome-wide co-ordination of transcription. Utilising a systems-based approach of analysing the integrated wheat's response to water stress, in terms of biological robustness theory, the findings suggest that each durum

  3. Impact of emerging clean vehicle system on water stress

    International Nuclear Information System (INIS)

    Cai, Hua; Hu, Xiaojun; Xu, Ming

    2013-01-01

    Graphical abstract: Display Omitted - Highlights: • Clean vehicles may increase US water consumption up to 2810 billion gallons/year. • Large-scale clean vehicle adoption could lead to severe regional water stress. • Fuel choice for clean vehicle is crucial in minimizing regional water stress. • Regional optimization illustrated the importance of regional consideration. - Abstract: While clean vehicles (i.e., vehicles powered by alternative fuels other than fossil fuels) offer great potential to reduce greenhouse gas emissions from gasoline-based vehicles, the associated impact on water resources has not yet been fully assessed. This research provides a systematic evaluation of the impact of a fully implemented clean vehicle system on national and state-level water demand and water stress. On the national level, based on existing policies, transitioning the current gasoline-based transportation into one with clean vehicles will increase national annual water consumption by 1950–2810 billion gallons of water, depending on the market penetration of electric vehicles. On the state level, variances of water efficiency in producing different fuels are significant. The fuel choice for clean vehicle development is especially crucial for minimizing water stress increase in states with already high water stress, high travel demands, and significant variations in water efficiency in producing different alternative fuels. Current development of clean vehicle infrastructure, however, has not reflected these state-level variations. This study takes an optimization approach to further evaluate impacts on state-level water stress from a fully implemented clean vehicle system and identified potential roles (fuel producer or consumer) states may play in real world clean vehicle development scenario. With an objective of minimizing overall water stress impact, our optimization model aims to provide an analytical framework to better assess impacts on state-level water

  4. Factors controlling plasticity of leaf morphology in Robinia pseudoacacia L. II: the impact of water stress on leaf morphology of seedlings grown in a controlled environment chamber

    Science.gov (United States)

    M.T. Tyree

    2012-01-01

    Context. The cause of morphological plasticity of leaves within the crowns of tall trees still debated. Whether it is driven by irradiance or hydraulic constraints is inconclusive. In a previous study, we hypothesized that water stress caused between-site and within-tree morphological variability in mature Robinia trees.

  5. Factors controlling plasticity of leaf morphology in Robinia pseudoacacia: III. biophysical constraints on leaf expansion under long-term water stress

    Science.gov (United States)

    Yanxiang ​Zhang; Maria Alejandra Equiza; Quanshui Zheng; Melvin T. Tyree

    2011-01-01

    In this article, we measured the relative growth rate (RGR) of leaves of Robinia pseudoacacia seedlings under well-watered and water-stressed conditions (mid-day Ψw = leaf water potential estimated with a pressure bomb of −0.48 and −0.98 MPa, respectively). Pressure–volume (PV) curves were done on growing leaves at 25, 50 and 95% of the mature size...

  6. Activities of fructan- and sucrose-metabolizing enzymes in wheat stems subjected to water stress during grain filling.

    Science.gov (United States)

    Yang, Jianchang; Zhang, Jianhua; Wang, Zhiqing; Zhu, Qingsen; Liu, Lijun

    2004-12-01

    This study investigated if a controlled water deficit during grain filling of wheat (Triticum aestivum L.) could accelerate grain filling by facilitating the remobilization of carbon reserves in the stem through regulating the enzymes involved in fructan and sucrose metabolism. Two high lodging-resistant wheat cultivars were grown in pots and treated with either a normal (NN) or high amount of nitrogen (HN) at heading time. Plants were either well-watered (WW) or water-stressed (WS) from 9 days post anthesis until maturity. Leaf water potentials markedly decreased at midday as a result of water stress but completely recovered by early morning. Photosynthetic rate and zeatin + zeatin riboside concentrations in the flag leaves declined faster in WS plants than in WW plants, and they decreased more slowly with HN than with NN when soil water potential was the same, indicating that the water deficit enhanced, whereas HN delayed, senescence. Water stress, both at NN and HN, facilitated the reduction in concentration of total nonstructural carbohydrates (NSC) and fructans in the stems but increased the sucrose level there, promoted the re-allocation of pre-fixed (14)C from the stems to grains, shortened the grain-filling period, and accelerated the grain-filling rate. Grain weight and grain yield were increased under the controlled water deficit when HN was applied. Fructan exohydrolase (FEH; EC 3.2.1.80) and sucrose phosphate synthase (SPS; EC 2.4.1.14) activities were substantially enhanced by water stress and positively correlated with the total NSC and fructan remobilization from the stems. Acid invertase (EC 3.2.1.26) activity was also enhanced by the water stress and associated with the change in fructan concentration, but not correlated with the total NSC remobilization and (14)C increase in the grains. Sucrose:sucrose fructosyltransferase (EC 2.4.1.99) activity was inhibited by the water stress and negatively correlated with the remobilization of carbon reserves

  7. Maintenance of water uptake and reduced water loss contribute to water stress tolerance of Spiraea alba Du Roi and Spiraea tomentosa L.

    Science.gov (United States)

    Stanton, Kelly M; Mickelbart, Michael V

    2014-01-01

    Two primarily eastern US native shrubs, Spiraea alba Du Roi and Spiraea tomentosa L., are typically found growing in wet areas, often with standing water. Both species have potential for use in the landscape, but little is known of their environmental requirements, including their adaptation to water stress. Two geographic accessions of each species were evaluated for their response to water stress under greenhouse conditions. Above-ground biomass, water relations and gas exchange were measured in well-watered and water stress treatments. In both species, water stress resulted in reduced growth, transpiration and pre-dawn water potential. However, both species also exhibited the ability to osmotically adjust to lower soil water content, resulting in maintained midday leaf turgor potential in all accessions. Net CO2 assimilation was reduced only in one accession of S. alba, primarily due to large reductions in stomatal conductance. S. tomentosa lost a larger proportion of leaves than S. alba in response to water stress. The primary water stress tolerance strategies of S. alba and S. tomentosa appear to be the maintenance of water uptake and reduced water loss.

  8. The impact of long-term water stress on relative growth rate and morphology of needles and shoots of Metasequoia glyptostroboides seedlings: research toward identifying mechanistic models.

    Science.gov (United States)

    Zhang, Yanxiang; Equiza, Maria Alejandra; Zheng, Quanshui; Tyree, Melvin T

    2011-09-01

    Leaf morphology in the upper canopy of trees tends to be different from that lower down. The effect of long-term water stress on leaf growth and morphology was studied in seedlings of Metasequoia glyptostroboides to understand how tree height might affect leaf morphology in larger trees. Tree height increases water stress on growing leaves through increased hydraulic resistance to water flow and increased gravitational potential, hence we assume that water stress imposed by soil dehydration will have an effect equivalent to stress induced by height. Seedlings were subjected to well-watered and two constant levels of long-term water stress treatments. Drought treatment significantly reduced final needle count, area and mass per area (leaf mass area, LMA) and increased needle density. Needles from water-stressed plants had lower maximum volumetric elastic modulus (ε(max)), osmotic potential at full turgor (Ψ¹⁰⁰(π)) (and at zero turgor (Ψ⁰(π)) (than those from well-watered plants. Palisade and spongy mesophyll cell size and upper epidermal cell size decreased significantly in drought treatments. Needle relative growth rate, needle length and cell sizes were linear functions of the daily average water potential at the time of leaf growth (r² 0.88-0.999). We conclude that water stress alone does mimic the direction and magnitude of changes in leaf morphology observed in tall trees. The results are discussed in terms of various models for leaf growth rate. Copyright © Physiologia Plantarum 2011.

  9. The Swedish mutant barley collection

    International Nuclear Information System (INIS)

    1989-01-01

    Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

  10. The Swedish mutant barley collection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-07-01

    Full text: The Swedish mutation research programme in barley began about 50 years ago and has mainly been carried out at Svaloev in co-operation with the institute of Genetics at the University of Lund. The collection has been produced from different Swedish high-yielding spring barley varieties, using the following mutagens: X-rays, neutrons, several organic chemical compounds such as ethyleneimine, several sulfonate derivatives and the inorganic chemical mutagen sodium azide. Nearly 10,000 barley mutants are stored in the Nordic Gene Bank and documented in databases developed by Udda Lundquist, Svaloev AB. The collection consists of the following nine categories with 94 different types of mutants: 1. Mutants with changes in the spike and spikelets; 2. Changes in culm length and culm composition; 3. Changes in growth types; 4. Physiological mutants; 5. Changes in awns; 6. Changes in seed size and shape; 7. Changes in leaf blades; 8. Changes in anthocyanin and colour; 9. Resistance to barley powdery mildew. Barley is one of the most thoroughly investigated crops in terms of induction of mutations and mutation genetics. So far, about half of the mutants stored at the Nordic Gene Bank, have been analysed genetically; They constitute, however, only a minority of the 94 different mutant types. The genetic analyses have given valuable insights into the mutation process but also into the genetic architecture of various characters. A number of mutants of two-row barley have been registered and commercially released. One of the earliest released, Mari, an early maturing, daylength neutral, straw stiff mutant, is still grown in Iceland. The Swedish mutation material has been used in Sweden, but also in other countries, such as Denmark, Germany, and USA, for various studies providing a better understanding of the barley genome. The collection will be immensely valuable for future molecular genetical analyses of clone mutant genes. (author)

  11. A Three-Dimensional Index for Characterizing Crop Water Stress

    Directory of Open Access Journals (Sweden)

    Jessica A. Torrion

    2014-05-01

    Full Text Available The application of remotely sensed estimates of canopy minus air temperature (Tc-Ta for detecting crop water stress can be limited in semi-arid regions, because of the lack of full ground cover (GC at water-critical crop stages. Thus, soil background may restrict water stress interpretation by thermal remote sensing. For partial GC, the combination of plant canopy temperature and surrounding soil temperature in an image pixel is expressed as surface temperature (Ts. Soil brightness (SB for an image scene varies with surface soil moisture. This study evaluates SB, GC and Ts-Ta and determines a fusion approach to assess crop water stress. The study was conducted (2007 and 2008 on a commercial scale, center pivot irrigated research site in the Texas High Plains. High-resolution aircraft-based imagery (red, near-infrared and thermal was acquired on clear days. The GC and SB were derived using the Perpendicular Vegetation Index approach. The Ts-Ta was derived using an array of ground Ts sensors, thermal imagery and weather station air temperature. The Ts-Ta, GC and SB were fused using the hue, saturation, intensity method, respectively. Results showed that this method can be used to assess water stress in reference to the differential irrigation plots and corresponding yield without the use of additional energy balance calculation for water stress in partial GC conditions.

  12. Leaf senescence and nutrient remobilisation in barley and wheat

    DEFF Research Database (Denmark)

    Gregersen, P L; Holm, P B; Krupinska, K

    2008-01-01

    Extensive studies have been undertaken on senescence processes in barley and wheat and their importance for the nitrogen use efficiency of these crop plants. During the senescence processes, proteins are degraded and nutrients are re-mobilised from senescing leaves to other organs, especially...... of chloroplasts is summarised. Rubisco is thought to be released from chloroplasts into vesicles containing stroma material (RCB = Rubisco-containing bodies). These vesicles may then take different routes for their degradation. Transcriptome analyses on barley and wheat senescence have identified genes involved...... in degradative, metabolic and regulatory processes that could be used in future strategies aimed at modifying the senescence process. The breeding of crops for characters related to senescence processes, e.g. higher yields and better nutrient use efficiency, is complex. Such breeding has to cope with the dilemma...

  13. Root hair mutants of barley

    International Nuclear Information System (INIS)

    Engvild, K.C.; Rasmussen, K.

    2005-01-01

    Barley mutants without root hairs or with short or reduced root hairs were isolated among M 2 seeds of 'Lux' barley (Hordeum vulgare L.) after acidified sodium azide mutagenesis. Root hair mutants are investigated intensively in Arabidopsis where about 40 genes are known. A few root hair mutants are known in maize, rice, barley and tomato. Many plants without root hairs grow quite well with good plant nutrition, and mutants have been used for investigations of uptake of strongly bound nutrients like phosphorus, iron, zinc and silicon. Seed of 'Lux' barley (Sejet Plant Breeding, Denmark) were soaked overnight, and then treated with 1.5-millimolarsodium azide in 0.1 molar sodium phosphate buffer, pH 3, for 2.5 hours according to the IAEA Manual on Mutation Breeding (2nd Ed.). After rinsing in tap water and air-drying, the M 2 seeds were sown in the field the same day. Spikes, 4-6 per M 1 plant, were harvested. The mutation frequency was similar to that obtained with other barley cultivars from which low-phytate mutants were isolated [5]. Seeds were germinated on black filter paper in tap water for 3 or 4 days before scoring for root hair mutants

  14. Plants in water-controlled ecosystems: active role in hydrologic processes and response to water stress. III. Vegetation water stress

    Science.gov (United States)

    Porporato, A.; Laio, F.; Ridolfi, L.; Rodriguez-Iturbe, I.

    The reduction of soil moisture content during droughts lowers the plant water potential and decreases transpiration; this in turn causes a reduction of cell turgor and relative water content which brings about a sequence of damages of increasing seriousness. A review of the literature on plant physiology and water stress shows that vegetation water stress can be assumed to start at the soil moisture level corresponding to incipient stomatal closure and reach a maximum intensity at the wilting point. The mean crossing properties of these soil moisture levels crucial for water stress are derived analytically for the stochastic model of soil moisture dynamics described in Part II (F. Laio, A. Porporato, L. Ridolfi, I. Rodriguez-Iturbe. Adv. Water Res. 24 (7) (2001) 707-723). These properties are then used to propose a measure of vegetation water stress which combines the mean intensity, duration, and frequency of periods of soil water deficit. The characteristics of vegetation water stress are then studied under different climatic conditions, showing how the interplay between plant, soil, and environment can lead to optimal conditions for vegetation.

  15. Variations in natural abundances of 15N and 13C in potassium fed lentil plants grown under water stress

    International Nuclear Information System (INIS)

    Kurdali, F.; Al-Shammaa, M.

    2007-12-01

    The impact of two K-fertilizer treatments [K0 (0) and K1 (150 kg K 2 O/ha)] on dry matter production and N 2 fixation (Ndfa) by Lentil (Lens culinaris.) was evaluated in a pot experiment. The plants were also subjected to three soil moisture regimes starting from bud flower initiation stage to pod formation (low, 45-50%; moderate, 55-60% and high 75-80% of field capacity, abbreviated as FC1, FC2 and FC3, respectively). The 15 N natural abundance technique (%δ 1 5 N) was employed to evaluate N 2 fixation using barley as a reference crop. Moreover, the carbon isotope discrimination (%Δ 13 C) was determined to assess factors responsible for crop performance variability in the different treatments. Water restriction occurring during the post-flowering period considerably affects growth and N 2 -fixation. However, K-fertilizer enhanced plant performance by overcoming water shortage influences. The δ 15 N values in lentils ranged from +0.67 to +1.36% depending on soil moisture and K-fertilizer treatments; whereas, those of N 2 fixation and the reference plant were -0.45 and +2.94%, respectively. Consequently, Ndfa% ranged from 45 and 65%. Water stress reduced Δ 13 C values in the FC1K0 And FC1K1 treatments. However, K fertilizer enhanced the whole plants Δ 13 C along with dry matter yield and N 2 fixation. The water stressed plants amended with K (FC1K1) seemed to be the best treatment because of its highest pod yield, high N balance and N 2 -fixation with low consumption of irrigation water. This illustrates the ecological and economical importance of K-fertilizer in alleviating water stress occurring during the post-flowering period of lentil.(Authors)

  16. Variations in natural abundances of 15N and 13C in potassium fed lentil plants grown under water stress

    International Nuclear Information System (INIS)

    Kurdali, F.; Al-Shammaa, M.

    2009-01-01

    The impact of two K-fertilizer treatments [K0 (0) and K1 (150 kg K 2 O/ha)] on dry matter production and N 2 fixation (Ndfa) by Lentil (Lens culinaris.) was evaluated in a pot experiment. The plants were also subjected to three soil moisture regimes starting from bud flower initiation stage to pod formation (low, 45-50%. Moderate, 55-60% and high 75-80% of field capacity, abbreviated as FC1, FC2 and FC3, respectively). The 15 N natural abundance technique (%δ 15 N) was employed to evaluate N 2 fixation using barley as a reference crop. Moreover, the carbon isotope discrimination (%Δ 13 C) was determined to assess factors responsible for crop performance variability in the different treatments. Water restriction occurring during the post-flowering period considerably affects growth and N 2 -fixation. However, K-fertilizer enhanced plant performance by overcoming water shortage influences. The delta 15 N values in lentils ranged from +0.67 to +1.36% depending on soil moisture and K-fertilizer treatments. Whereas, those of N 2 fixation and the reference plant were -0.45 and +2.94%, respectively. Consequently, Ndfa% ranged from 45 and 65%. Water stress reduced Δ 13 C values in the FC1K0 And FC1K1 treatments. However, K fertilizer enhanced the whole plants Δ 13 C along with dry matter yield and N 2 fixation. The water stressed plants amended with K (FC1K1) seemed to be the best treatment because of its highest pod yield, high N balance and N 2 -fixation with low consumption of irrigation water. This illustrates the ecological and economical importance of K-fertilizer in alleviating water stress occurring during the post-flowering period of lentil.(Authors)

  17. Effect of Mild Water Stress and Enhanced Ultraviolet-B Irradiation on Leaf Growth of Rumex obtusifolius L. and Rumex patientia L. (Polygonaceae).

    OpenAIRE

    Holman, Steven R.

    1981-01-01

    Leaves of Rumex obtusifolius L. and R. patientia L.were exposed to combinations of mild water stress and enhanced ultraviolet-B irradiation during their ontogeny. Two UV-B treatments (enhanced UV-B and control) and three water stress treatments (-0.0 MPa, -0.2 MPa and -0.4 MPa rooting medium matric potentials) were employed. The impact of the stress interaction was assessed on the basis of changes in leaf area, average adaxial epidermal cell size, and total number of adaxial epidermal cells p...

  18. Biochemical response of hybrid black poplar tissue culture (Populus × canadensis) on water stress.

    Science.gov (United States)

    Popović, B M; Štajner, D; Ždero-Pavlović, R; Tari, I; Csiszár, J; Gallé, Á; Poór, P; Galović, V; Trudić, B; Orlović, S

    2017-05-01

    In this study, poplar tissue culture (hybrid black poplar, M1 genotype) was subjected to water stress influenced by polyethyleneglycol 6000 (100 and 200 mOsm PEG 6000). The aim of the research was to investigate the biochemical response of poplar tissue culture on water deficit regime. Antioxidant status was analyzed including antioxidant enzymes, superoxide-dismutase (SOD), catalase (CAT), guiacol-peroxidase (GPx), glutathione-peroxidase (GSH-Px), glutathione-reductase, reduced glutathione, total phenol content, Ferric reducing antioxidant power and DPPH radical antioxidant power. Polyphenol oxidase and phenylalanine-ammonium-lyase were determined as enzymatic markers of polyphenol metabolism. Among oxidative stress parameters lipid peroxidation, carbonyl-proteins, hydrogen-peroxide, reactive oxygen species, nitric-oxide and peroxynitrite were determined. Proline, proline-dehydrogenase and glycinebetaine were measured also as parameters of water stress. Cell viability is finally determined as a biological indicator of osmotic stress. It was found that water stress induced reactive oxygen and nitrogen species and lipid peroxidation in leaves of hybrid black poplar and reduced cell viability. Antioxidant enzymes including SOD, GPx, CAT and GSH-Px were induced but total phenol content and antioxidant capacity were reduced by PEG 6000 mediated osmotic stress. The highest biochemical response and adaptive reaction was the increase of proline and GB especially by 200 mOsm PEG. While long term molecular analysis will be necessary to fully address the poplar potentials for water stress adaptation, our results on hybrid black poplar suggest that glycine-betaine, proline and PDH enzyme might be the most important markers of poplar on water stress and that future efforts should be focused on these markers and strategies to enhance their concentration in poplar.

  19. Detecting long-term low-irradiance stress and water stress of trees with laser-induced fluorescence measurements

    International Nuclear Information System (INIS)

    Sagawa, M.; Kurata, K.; Takahashi, K.; Mineuchi, K.

    2001-01-01

    The objective of this study was to find simple and objective methods of diagnosing the ailments of trees in indoor spaces, such as atriums. In this study, two simple diagnostics were compared. One was the analysis of the laser-induced fluorescence spectra of leaves and the other was the analysis of the laser-induced chlorophyll-fluorescence induction kinetics (Kautsky effect). In the latter analysis, second time derivatives of the induction-kinetics curves were used. Cinnamomum camphora and Quercus myrsinifolia grown under different light conditions and Cinnamomum camphora under water stress were used in the experiments. The effects of low irradiance were detected in both the induction kinetics and the spectra; however, the effects of water stress were detected in the induction kinetics only. These results indicate the possibility of utilizing laser-induced-fluorescence induction-kinetics for diagnosing the ailments of trees. (author)

  20. Water stress induces overexpression of superoxide dismutases that ...

    African Journals Online (AJOL)

    SERVER

    2007-09-05

    Sep 5, 2007 ... Water stress is known to induce active oxygen species in plants. ... photosystem II photochemistry and whole plant growth against oxidative stress in these plants. ..... CO2. Plant Physiol. 110: 393-402. Sen Gupta A, Heinen JL, ...

  1. Water stress effects on spatially referenced cotton crop canopy properties

    Science.gov (United States)

    rop canopy temperature is known to be affected by water stress. Canopy reflectance can also be impacted as leaf orientation and color respond to the stress. As sensor systems are investigated for real-time management of irrigation and nitrogen, it is essential to understand how the data from the sen...

  2. Transient water stress in a vegetation canopy - Simulations and measurements

    Science.gov (United States)

    Carlson, Toby N.; Belles, James E.; Gillies, Robert R.

    1991-01-01

    Consideration is given to observational and modeling evidence of transient water stress, the effects of the transpiration plateau on the canopy radiometric temperature, and the factors responsible for the onset of the transpiration plateau, such as soil moisture. Attention is also given to the point at which the transient stress can be detected by remote measurement of surface temperature.

  3. Multi-modal sensor system for plant water stress assessment

    Science.gov (United States)

    Plant stress critically affects plant growth and causes significant loss of productivity and quality. When the plant is under water stress, it impedes photosynthesis and transpiration, resulting in changes in leaf color and temperature. Leaf discoloration in photosynthesis can be assessed by measu...

  4. Water stress induced changes in antioxidant enzymes, membrane ...

    African Journals Online (AJOL)

    Water stress induced changes in antioxidant enzymes membrane stablity index and seed protein profiling of four different wheat (Triticum aestivum L.) accessions (011251, 011417, 011320 and 011393) were determined in a pot study under natural condition during the wheat-growing season 2005 and 2006. Sampling was ...

  5. Biomass production and potential water stress increase with ...

    African Journals Online (AJOL)

    The choice of planting density and tree genotype are basic decisions when establishing a forest stand. Understanding the interaction between planting density and genotype, and their relationship with biomass production and potential water stress, is crucial as forest managers are faced with a changing climate. However ...

  6. Pure culture response of ectomycorrhizal fungi to imposed water stress

    Science.gov (United States)

    Mark D. Coleman; Caroline S. Bledsoe; William Lopushinsky

    1989-01-01

    The ability of ectomycorrhizal fungal isolates to tolerate imposed water stress in pure culture was examined in 55 isolates of 18 species. Water potential treatments, adjusted with polyethylene glycol, were applied to Petri dish units. These units allowed colony diameter measurements of fungi grown on liquid media. Delayed growth initiation and inhibition of growth...

  7. Forest productivity and water stress in Amazonia: observations from GOSAT chlorophyll fluorescence.

    Science.gov (United States)

    Lee, Jung-Eun; Frankenberg, Christian; van der Tol, Christiaan; Berry, Joseph A; Guanter, Luis; Boyce, C Kevin; Fisher, Joshua B; Morrow, Eric; Worden, John R; Asefi, Salvi; Badgley, Grayson; Saatchi, Sassan

    2013-06-22

    It is unclear to what extent seasonal water stress impacts on plant productivity over Amazonia. Using new Greenhouse gases Observing SATellite (GOSAT) satellite measurements of sun-induced chlorophyll fluorescence, we show that midday fluorescence varies with water availability, both of which decrease in the dry season over Amazonian regions with substantial dry season length, suggesting a parallel decrease in gross primary production (GPP). Using additional SeaWinds Scatterometer onboard QuikSCAT satellite measurements of canopy water content, we found a concomitant decrease in daily storage of canopy water content within branches and leaves during the dry season, supporting our conclusion. A large part (r(2) = 0.75) of the variance in observed monthly midday fluorescence from GOSAT is explained by water stress over moderately stressed evergreen forests over Amazonia, which is reproduced by model simulations that include a full physiological representation of photosynthesis and fluorescence. The strong relationship between GOSAT and model fluorescence (r(2) = 0.79) was obtained using a fixed leaf area index, indicating that GPP changes are more related to environmental conditions than chlorophyll contents. When the dry season extended to drought in 2010 over Amazonia, midday basin-wide GPP was reduced by 15 per cent compared with 2009.

  8. A transcriptional approach to unravel the connection between phospholipases A₂ and D and ABA signal in citrus under water stress.

    Science.gov (United States)

    Romero, Paco; Lafuente, M Teresa; Alférez, Fernando

    2014-07-01

    The effect of water stress on the interplay between phospholipases (PL) A2 and D and ABA signalling was investigated in fruit and leaves from the sweet orange Navelate and its fruit-specific ABA-deficient mutant Pinalate by studying simultaneously expression of 5 PLD and 3 PLA2-encoding genes. In general, expression levels of PLD-encoding genes were higher at harvest in the flavedo (coloured outer part of the peel) from Pinalate. Moreover, a higher and transient increase in expression of CsPLDα, CsPLDβ, CsPLDδ and CsPLDζ was observed in the mutant as compared to Navelate fruit under water stress, which may reflect a mechanism of acclimation to water stress influenced by ABA deficiency. An early induction in CsPLDγ gene expression, when increase in peel damage during fruit storage was most evident, suggested a role for this gene in membrane degradation processes during water stress. Exogenous ABA on mutant fruit modified the expression of all PLD genes and reduced the expression of CsPLDα and CsPLDβ by 1 week to levels similar to those of Navelate, suggesting a repressor role of ABA on these genes. In general, CssPLA2α and β transcript levels were lower in flavedo from Pinalate than from Navelate fruit during the first 3 weeks of storage, suggesting that expression of these genes also depends at least partially on ABA levels. Patterns of expression of PLD and PLA2-encoding genes were very similar in Navelate and Pinalate leaves, which have similar ABA levels, when comparing both RH conditions. Results comparison with other from previous works in the same experimental systems helped to decipher the effect of the stress severity on the differential response of some of these genes under dehydration conditions and pointed out the interplay between PLA2 and PLD families and their connection with ABA signalling in citrus. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. The Stimulation Effects of N+ Ion Beam on Liquorice and Its Influence on Water Stress

    International Nuclear Information System (INIS)

    Wei Shenglin; Liu Jingnan; Wu Lijun; Wang Jiabao; Yu Zengliang

    2006-01-01

    We have developed a large number of exocrine glands on liquorice leaves and facilitated polysaccharide secretion. Liquorice polysaccharide possesses stronger bound water affinity to gaseous water compared with sucrose and glucose. Our results show that the bound water affinity of liquorice polysaccharide to gaseous water is 49.75% higher than glucose (p + implantation (total dosage of 4.68x10 16 ions/cm 2 and energy of 20 keV) into dry liquorice seeds, both the bound water affinity to gaseous water and the bound water content of dry liquorice leaf can be significantly increased 30.24% ( p + implantation into dry liquorice seeds, the leaf polysaccharide content under water stress (ψ w = -1.5 MPa) can increase significantly (p<0.05) and the plant growth can also improve significantly (p<0.05)

  10. Selection of Almond Vegetative Rootstocks for Water Stress Tolerance Based on the Morphological Markers

    Directory of Open Access Journals (Sweden)

    A.A. Shokouhian

    2016-02-01

    677 and selected natural hybrid of peach × almond (H1and H2, and almond vegetative rootstock (local control.In this study,EMtreatments for 60 days before stress treatments were applied so that in each irrigation, EM solution to a concentration of one percent was given to half of the experiment pots. Other pots were irrigated equally with normal water. Stress levels were applied from July as follow: full irrigation, watering after unloading 33% and 66% soil moisture availability. In order to evaluate the performance, seedling survival, plant growth, number of leaves, leaf area, root fresh and dry weight and leaves and root length were measured. Results and Discussion: Analysis of variance showed that between rootstock levels across all treatments were significantly differences at 0.01 level of probability. Comparison of means showed that the highest fresh and dry weight and leaf are awere observed forGF677and H1.Rootstockannualgrowth rate was also different. Most of the growth was related to the H1 Rootstocks. Thes urvival ratewas significantly different from the Rootstocks ofGF677,andH1showedthe highestpercentage of survival. The degree of adaptation to drought in varieties of almonds is different. The results showed that changes ingrowthparametersinGF677and H1were observed less often than other rootstocks. Because of strong roots,GF677and H1continue to attract more minerals under stress conditions. Analysis of variance showed that the between irrigation levels for all treatments were significantly different at 0.01 level of probability. Comparison of means showed that among the study traits, the highest amount was obtained from complete irrigation, while irrigationat66 percenthad the least amount. Water stress may directly affect photosyn thesis, through leaf photochemicalprocessorindirectly,byclosing stomata, reducingleaf area and growth. The results showed that the levels of(EM on the leaf surface, leaf number, annual growth, root dry weight and volume were

  11. Some Root Traits of Barley (Hordeum vulgare L. as Affected by Mycorrhizal Symbiosis under Drought Stress

    Directory of Open Access Journals (Sweden)

    R. Bayani

    2016-05-01

    Full Text Available The effect of drought stress and mycorrhizal symbiosis on the colonization, root and leaf phosphorous content, root and leaf phosphatase activity, root volume and area as well as shoot dry weight of a variety of hulless barley were evaluated using a completely randomized experimental design (CRD with 3 replications. Treatments were three levels of drought stress of 30, 60 and 90% field capacity and two levels of mycorrhizal with and without inoculation. According to the results, the highest value of leaf phosphorous (1.54 mg/g was observed at mycorrhizal symbiosis against severe drought treatment. Root phosphatase activity was highest (297.9 OD min -1 FW-1 at severe drought stress with mycorrhizal symbiosis which in comparison with mild stress in the presence of mycorrhiza showed 16.6 fold increasing. The control and non-mycorrhizal symbiosis treatments had highest root dry weight (0.091 g. The lowest root volume (0.016 cm2 observed at mycorrhizal symbiosis × severe drought treatment. Generally, Inoculation of barley seed with mycorrhiza at severe water stress could transport more phosphorous to shoot, especially leaf via inducing of leaf and root phosphatase activity. Also, in addition to supply of nutrient sources especially phosphorous for plant, mycorrhizal symbiosis could play an important role in withstanding water stress in plant via increasing of root dry weight and area.

  12. Water stress assessment of cork oak leaves and maritime pine needles based on LIF spectra

    Science.gov (United States)

    Lavrov, A.; Utkin, A. B.; Marques da Silva, J.; Vilar, Rui; Santos, N. M.; Alves, B.

    2012-02-01

    The aim of the present work was to develop a method for the remote assessment of the impact of fire and drought stress on Mediterranean forest species such as the cork oak ( Quercus suber) and maritime pine ( Pinus pinaster). The proposed method is based on laser induced fluorescence (LIF): chlorophyll fluorescence is remotely excited by frequency-doubled YAG:Nd laser radiation pulses and collected and analyzed using a telescope and a gated high sensitivity spectrometer. The plant health criterion used is based on the I 685/ I 740 ratio value, calculated from the fluorescence spectra. The method was benchmarked by comparing the results achieved with those obtained by conventional, continuous excitation fluorometric method and water loss gravimetric measurements. The results obtained with both methods show a strong correlation between them and with the weight-loss measurements, showing that the proposed method is suitable for fire and drought impact assessment on these two species.

  13. Will climate change exacerbate water stress in Central Asia?

    DEFF Research Database (Denmark)

    Siegfried, Tobias; Bernauer, Thomas; Guiennet, Renaud

    2012-01-01

    the Soviet Union collapsed. Will climate change exacerbate water stress and thus conflicts? We have developed a coupled climate, land-ice and rainfall-runoff model for the Syr Darya to quantify impacts and show that climatic changes are likely to have consequences on runoff seasonality due to earlier snow......-melt. This will increase water stress in unregulated catchments because less water will be available for irrigation in the summer months. Threats from geohazards, above all glacier lake outbursts, are likely to increase as well. The area at highest risk is the densely populated, agriculturally productive, and politically......Millions of people in the geopolitically important region of Central Asia depend on water from snow- and glacier-melt driven international rivers, most of all the Syr Darya and Amu Darya. The riparian countries of these rivers have experienced recurring water allocation conflicts ever since...

  14. Influence of water stress on Botryosphaeriaceae disease expression in grapevines

    Directory of Open Access Journals (Sweden)

    Jan VAN NIEKERK

    2011-12-01

    Full Text Available Several species in Botryosphaeriaceae have been associated with grapevine trunk diseases. To evaluate the effect of water stress on infection of grapevines by Botryosphaeriaceae spp., 1-year-old Shiraz/101-14 Mgt nursery grapevine plants were planted in plastic potting bags and placed outdoors under shade netting. Five weeks after planting, vines were pruned and the pruning wounds inoculated with spore suspensions of Neofusicoccum australe, Neofusicoccum parvum, Lasiodiplodia theobromae or Diplodia seriata. Control treatments consisted of applications of sterile water or a Trichoderma harzianum spore suspension. Stem inoculations were done by inserting a colonised or uncolonised agar plug into a wound made in each stem. Four different irrigation regimes were introduced 12 weeks after planting to simulate varying degrees of water stress. Measurements of stomatal conductance, photosynthetic rate and leaf spectrometry were made to monitor physiological stress. Eight months after inoculation, vines were uprooted and the root, shoot and plant mass of each vine determined. Lesions observed in the inoculated pruning wounds and stems were also measured. Vines subjected to the lowest irrigation regime were significantly smaller than optimally irrigated vines. Water stressed vines also had significantly lower photosynthetic rates and levels of stomatal conductance compared with vines receiving optimal irrigation, indicating that these plants experienced significantly higher levels of physiological stress. The mean lesion length was significantly longer in the pruning wounds and stems of plants subjected to the lowest irrigation regime, with lesion length declining linearly with increasing irrigation volume. These results clearly indicate that when a grapevine is exposed to water stress, colonisation and disease expression by Botryosphaeriaceae spp. are much more severe.

  15. Physiological Assessment of Water Stress in Potato Using Spectral Information.

    Science.gov (United States)

    Romero, Angela P; Alarcón, Andrés; Valbuena, Raúl I; Galeano, Carlos H

    2017-01-01

    Water stress in potato ( Solanum tuberosum L.) causes considerable losses in yield, and therefore, potato is often considered to be a drought sensitive crop. Identification of water deficit tolerant potato genotypes is an adaptation strategy to mitigate the climatic changes that are occurring in the Cundiboyacense region in Colombia. Previous studies have evaluated potato plants under water stress conditions using physiological analyses. However, these methodologies require considerable amounts of time and plant material to perform these measurements. This study evaluated and compared the physiological and spectral traits between two genotypes, Diacol Capiro and Perla Negra under two drought levels (10 and 15 days without irrigation from flowering). Reflectance information was used to calculate indexes which were associated with the physiological behavior in plants. The results showed that spectral information was correlated (ρ < 0.0001) with physiological variables such as foliar area (FA), total water content (H 2 Ot), relative growth rate of potato tubers (RGTtub), leaf area ratio (LAR), and foliar area index (AFI). In general, there was a higher concentration of chlorophyll under drought treatments. In addition, Perla Negra under water deficit treatments did not show significant differences in its physiological variables. Therefore, it could be considered a drought tolerant genotype because its physiological performance was not affected under water stress conditions. However, yield was affected in both genotypes after being subject to 15 days of drought. The results suggested that reflectance indexes are a useful and affordable approach for potato phenotyping to select parent and segregant populations in breeding programs.

  16. Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

    Directory of Open Access Journals (Sweden)

    Popović Zorica

    2010-01-01

    Full Text Available Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C (soil water regime in pots was maintained at the level of field water capacity and treated (water-stressed, WS (soil water regime was maintained in the range of wilting point and lentocapillary capacity. The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively, which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively. Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½. Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.

  17. The Hv NAC6 transcription factor: a positive regulator of penetration resistance in barley and Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Michael Krogh; Rung, Jesper Henrik; Gregersen, Per Langkjaer

    2007-01-01

    Pathogens induce the expression of many genes encoding plant transcription factors, though specific knowledge of the biological function of individual transcription factors remains scarce. NAC transcription factors are encoded in plants by a gene family with proposed functions in both abiotic...... and biotic stress adaptation, as well as in developmental processes. In this paper, we provide convincing evidence that a barley NAC transcription factor has a direct role in regulating basal defence. The gene transcript was isolated by differential display from barley leaves infected with the biotrophic...... powdery mildew fungus, Blumeria graminis f.sp. hordei (Bgh). The full-length cDNA clone was obtained using 5'-RACE and termed HvNAC6, due to its high similarity to the rice homologue, OsNAC6. Gene silencing of HvNAC6 during Bgh inoculation compromises penetration resistance in barley epidermal cells...

  18. Nitrogen metabolism correlates with the acclimation of photosynthesis to short-term water stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Zhong, Chu; Cao, Xiaochuang; Bai, Zhigang; Zhang, Junhua; Zhu, Lianfeng; Huang, Jianliang; Jin, Qianyu

    2018-04-01

    Nitrogen metabolism is as sensitive to water stress as photosynthesis, but its role in plant under soil drying is not well understood. We hypothesized that the alterations in N metabolism could be related to the acclimation of photosynthesis to water stress. The features of photosynthesis and N metabolism in a japonica rice 'Jiayou 5' and an indica rice 'Zhongzheyou 1' were investigated under mild and moderate soil drying with a pot experiment. Soil drying increased non-photochemical quenching (NPQ) and reduced photon quantum efficiency of PSII and CO 2 fixation in 'Zhongzheyou 1', whereas the effect was much slighter in 'Jiayou 5'. Nevertheless, the photosynthetic rate of the two cultivars showed no significant difference between control and water stress. Soil drying increased nitrate reducing in leaves of 'Zhongzheyou 1', characterized by enhanced nitrate reductase (NR) activity and lowered nitrate content; whereas glutamate dehydrogenase (GDH), glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) were relative slightly affected. 'Jiayou 5' plants increased the accumulation of nitrate under soil drying, although its NR activity was increased. In addition, the activities of GDH, GOT and GPT were typically increased under soil drying. Besides, amino acids and soluble sugar were significantly increased under mild and moderate soil drying, respectively. The accumulation of nitrate, amino acid and sugar could serve as osmotica in 'Jiayou 5'. The results reveal that N metabolism plays diverse roles in the photosynthetic acclimation of rice plants to soil drying. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  19. Identification of PEG-induced water stress responsive transcripts using co-expression network in Eucalyptus grandis.

    Science.gov (United States)

    Ghosh Dasgupta, Modhumita; Dharanishanthi, Veeramuthu

    2017-09-05

    Ecophysiological studies in Eucalyptus have shown that water is the principal factor limiting stem growth. Effect of water deficit conditions on physiological and biochemical parameters has been extensively reported in Eucalyptus. The present study was conducted to identify major polyethylene glycol induced water stress responsive transcripts in Eucalyptus grandis using gene co-expression network. A customized array representing 3359 water stress responsive genes was designed to document their expression in leaves of E. grandis cuttings subjected to -0.225MPa of PEG treatment. The differentially expressed transcripts were documented and significantly co-expressed transcripts were used for construction of network. The co-expression network was constructed with 915 nodes and 3454 edges with degree ranging from 2 to 45. Ninety four GO categories and 117 functional pathways were identified in the network. MCODE analysis generated 27 modules and module 6 with 479 nodes and 1005 edges was identified as the biologically relevant network. The major water responsive transcripts represented in the module included dehydrin, osmotin, LEA protein, expansin, arabinogalactans, heat shock proteins, major facilitator proteins, ARM repeat proteins, raffinose synthase, tonoplast intrinsic protein and transcription factors like DREB2A, ARF9, AGL24, UNE12, WLIM1 and MYB66, MYB70, MYB 55, MYB 16 and MYB 103. The coordinated analysis of gene expression patterns and coexpression networks developed in this study identified an array of transcripts that may regulate PEG induced water stress responses in E. grandis. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Isozyme differences in barley mutants

    Energy Technology Data Exchange (ETDEWEB)

    AI-Jibouri, A A.M.; Dham, K M [Department of Botany, Nuclear Research Centre, Baghdad (Iraq)

    1990-01-01

    Full text: Thirty mutants (M{sub 11}) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

  1. Isozyme differences in barley mutants

    International Nuclear Information System (INIS)

    AI-Jibouri, A.A.M.; Dham, K.M.

    1990-01-01

    Full text: Thirty mutants (M 11 ) of barley (Hordeum vulgare L.) induced by physical and chemical mutagens were analysed for isozyme composition using polyacrylamide gel electrophoresis. Results show that these mutants were different in the isozymes leucine aminopeptidase, esterase and peroxidase. The differences included the number of forms of each enzyme, relative mobility value and their intensity on the gel. Glutamate oxaloacetate transaminase isozyme was found in six molecular forms and these forms were similar in all mutants. (author)

  2. Mutation breeding in malting barley

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, Makoto; Sanada, Matsuyoshi

    1984-03-01

    The released varieties of malting barley through mutation breeding is more than ten in number, including foreign varieties. In Japan four varieties has been released so far. We started mutation breeding in 1956 together with cross breeding that we employed before. Until now, Gamma 4, Amagi Nijo 1 and Fuji Nijo 2 have been produced from the direct use of induced mutations and Nirasaki Nijo 8 from the indirect use of them. Mutation breeding has been used mainly in the partial improvement of agronomic characteristics since the selection for malting quality was very complicated. As the variety bred by induced mutation is usually equivalent to the original variety in malting quality, both this new variety and the original one could be cultivated in the same area without any problem on later malt production. Particularly when one farmer cultivates barley in an extensive acreage, he can harvest at the best time according to the different maturing time of each variety. From these points of view, mutation breeding is an efficient tool in malting barley breeding. Mutagens we have used so far are X-rays, ..gamma..-rays, neutron and chemicals such as dES. From our experience in selection, the low dose of radiation and chemical mutagens are more effective in selection of point mutation than the high dose of radiation which tends to produce many abnormal but few practical mutants. (author).

  3. Gravimorphism in rice and barley: promotion of leaf elongation by vertical inversion in agravitropically growing plants.

    Science.gov (United States)

    Abe, K; Takahashi, H; Suge, H

    1998-12-01

    We have compared shoot responses of agravitropic rice and barley plants to vertical inversion with those of normal ones. When rice plants were vertically inverted, the main stems of a japonica type of rice, cv. Kamenoo, showed negative gravitropism at nodes 2-15 of both elongated and non-elongated internodes. However, shoots of lazy line of rice, lazy-Kamenoo, bent gravitropically at nodes 11-15 only elongated internodes but not at nodes 2-10 of non-elongated ones. Thus, shoots of Kamenoo responded gravitropically at all stages of growth, whereas shoots of lazy-Kamenoo did not show gravitropic response before heading. In Kamenoo plants, lengths of both leaf-sheath and leaf-blade were shortened by vertical inversion, but those of the vertically inverted plants of lazy-Kamenoo were significantly longer than the plants in an upright position. When agravitropic and normal plants of barley were vertically inverted, the same results as in rice were obtained; elongation of both leaf-sheath and leaf-blade was inhibited in normal barley plants, Chikurin-Ibaragi No. 1, but significantly stimulated in agravitropic plants of serpentina barley. These results suggest that vertical inversion of rice and barley plants enhances the elongation growth of leaves in the absence of tropistic response.

  4. Transient Overexpression of HvSERK2 Improves Barley Resistance to Powdery Mildew.

    Science.gov (United States)

    Li, Yingbo; Li, Qingwei; Guo, Guimei; He, Ting; Gao, Runhong; Faheem, Muhammad; Huang, Jianhua; Lu, Ruiju; Liu, Chenghong

    2018-04-18

    Somatic embryogenesis receptor-like kinases (SERKs) play an essential role in plant response to pathogen infection. Here we identified three SERK genes ( HvSERK1/2/3 ) from barley, and aimed to determine their implication in defense responses to barley powdery mildew ( Bgh ). Although HvSERK1/2/3 share the characteristic domains of the SERK family, only HvSERK2 was significantly induced in barley leaves during Bgh infection. The expression of HvSERK2 was rapidly induced by hydrogen peroxide (H₂O₂) treatment, but not by treatment with salicylic acid (SA), methyl jasmonate (MeJA), ethephon (ETH), or abscisic acid (ABA). Bioinformatics analysis of the cloned HvSERK2 promoter revealed that it contains several elements responsible for defense responses against pathogens. Promoter functional analysis showed that the HvSERK2 promoter was induced by Bgh and H₂O₂. Subcellular localization analysis of HvSERK2 indicated that it is mainly located on the plasma membrane. Transient overexpression of HvSERK2 in epidermal cells of the susceptible barley cultivar Hua 30 reduced the Bgh haustorium index from 58.6% to 43.2%. This study suggests that the HvSERK2 gene plays a positive role in the improvement of barley resistance to powdery mildew, and provides new insight into the function of SERK genes in the biotic stress response of plants.

  5. Taking Leave?

    CERN Multimedia

    2000-01-01

    Planning a holiday? Then if you're a member of the personnel, you'll need to use the Laboratory's new leave system that will be put in place on 1 October. Leave allocations don't change - you are entitled to just as much holiday as before - but instead of being credited annually, your leave will be credited on a monthly basis, and this information will be communicated on your salary slip. The reason for the change is that with the various new leave schemes such as Recruitment by Saved Leave (RSL) and the Progressive Retirement Programme (PRP), a streamlined procedure was required for dealing with all kinds of leave. In the new system, each member of the personnel will have leave accounts to which leave will be credited monthly from the payroll and debited each time an absence is registered in the CERN Electronic Document Handling system (EDH). Leave balances will appear on monthly pay slips, and full details of leave transactions and balances will be available through EDH at all times. As the leave will be c...

  6. 11C-methionine translocation in barley

    International Nuclear Information System (INIS)

    Nakanishi, Hiromi; Bughio, Naimatullah; Shigeta Ishioka, Noriko

    2000-01-01

    11 C-methionine was supplied to barley plants through a single leaf or via the roots and real time 11 C movement was monitored using a PETIS (positron emitting tracer imaging system). In Fe-deficient plants, 11 C-methionine was translocated from the tip of the absorbing leaf to the discrimination center' at the basal part of the shoot and then retranslocated to all the chlorotic leaves, while a negligible amount was retranslocated to the roots. In Fe-sufficient plants, methionine was translocated from the absorbing leaf to the discrimination center and then only to the newest leaf on the main shoot. A negligible amount was also retranslocated to the roots. Although, in Fe-sufficient plants, methionine translocation was observed from absorbing roots to shoots, in Fe-deficient plants, only a little amount was translocated from roots to shoots. In conclusion, methionine from the upper portion of a plant is not used as a precursor of mugineic acid under Fe-deficiency conditions. (author)

  7. [Effects of soil water status on gas exchange of peanut and early rice leaves].

    Science.gov (United States)

    Chen, Jiazhou; Lü, Guoan; He, Yuanqiu

    2005-01-01

    The gas exchange characteristics of peanut and early rice leaves were investigated in experimental plots under different soil water conditions over a long growth period. The results showed that at the branching stage of peanut, the stomatal conductance (Gs) and transpiration rate (Tr) decreased slightly under mild and moderate soil water stress, while the net photosynthetic rate (Pn) and leaf water use efficiency (WUE) increased. The Gs/Tr ratio also increased under mild water stress, but decreased under moderate water stress. At podding stage, the Gs, Tr, Gs/Tr ratio and Pn decreased, while WUE increased significantly under mild and moderate water stress. The peanut was suffered from water stress at its pod setting stage. At the grain filling stage of early rice, the Gs, Tr and Gs/Tr ratio fluctuated insignificantly under mild and moderate water stress, while Pn and WUE increased significantly, with an increase in grain yield under mild water stress. It's suggested that the combination of Gs and Gs/Tr ratio could be a reference index for crop water stress, namely, crops could be hazarded by water stress when Gs and Gs/Tr decreased synchronously.

  8. COMPARISON OF THE FROST RESISTANCE OF BARLEY ...

    African Journals Online (AJOL)

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    immediate recovery of the photosynthetic quantum yield after freezing. Landraces which showed the highest cold tolerance were found to acclimatize best. Key words/phrases: Barley, chlorophyll fluorescence, cold acclimation, Ethiopia, frost tolerance. INTRODUCTION. Barley (Hordeum vulgare L.) is a traditional crop.

  9. Cryosphere, climate and capitalism: drivers of Central Asian water stress

    Science.gov (United States)

    Hill, A. F.; Minbaeva, C.; Wilson, A. M.; Satylkanov, R.; Armstrong, R. L.

    2017-12-01

    The importance of meltwater to Central Asia's trans-boundary rivers and groundwater reserves suggests future water stress for the region. Climate is likely to induce shifts in water supply volume and delivery timing, while a complex fabric of socio-political factors complicates water management and adaptation strategies. To clarify the drivers of water stress over a large scale (440km, 4,200m elevation change), we conducted a socio-hydrologic study of Krygyzstan's Naryn River in the Tien Shan mountains, headwater stem of the Syr Darya and source of the disappearing Aral Sea. Using a combination of geochemical sampling, hydro-chemical mixing models, remote sensing image processing and community surveys, we characterized both the social and hydrologic controls of water supplies from glacier snout to downstream areas where people, hydropower and agriculture utilize water. We find melt-sourced water dominates hydrologic inputs to both surface flow and groundwater from headwaters to reservoir, suggesting high sensitivity of water supply to a warming climate. On a regional scale, the importance of melt to trans-boundary river flow serving thirsty downstream countries may increase hostility between already tense neighbors. Water stress on the basin level, however, is currently less impacted by supply than by access, agricultural knowledge deficiencies and infrastructure issues that are relic from the post-Soviet transition in the 1990s. The interplay of these factors suggests the need for creative and proactive water management adaptation planning in the Naryn basin and throughout similar melt-reliant areas of arid Central Asia.

  10. Water Stress Scatters Nitrogen Dilution Curves in Wheat

    Directory of Open Access Journals (Sweden)

    Marianne Hoogmoed

    2018-04-01

    Full Text Available Nitrogen dilution curves relate a crop’s critical nitrogen concentration (%Nc to biomass (W according to the allometric model %Nc = a W-b. This model has a strong theoretical foundation, and parameters a and b show little variation for well-watered crops. Here we explore the robustness of this model for water stressed crops. We established experiments to examine the combined effects of water stress, phenology, partitioning of biomass, and water-soluble carbohydrates (WSC, as driven by environment and variety, on the %Nc of wheat crops. We compared models where %Nc was plotted against biomass, growth stage and thermal time. The models were similarly scattered. Residuals of the %Nc - biomass model at anthesis were positively related to biomass, stem:biomass ratio, Δ13C and water supply, and negatively related to ear:biomass ratio and concentration of WSC. These are physiologically meaningful associations explaining the scatter of biomass-based dilution curves. Residuals of the thermal time model showed less consistent associations with these variables. The biomass dilution model developed for well-watered crops overestimates nitrogen deficiency of water-stressed crops, and a biomass-based model is conceptually more justified than developmental models. This has implications for diagnostic and modeling. As theory is lagging, a greater degree of empiricism might be useful to capture environmental, chiefly water, and genotype-dependent traits in the determination of critical nitrogen for diagnostic purposes. Sensitivity analysis would help to decide if scaling nitrogen dilution curves for crop water status, and genotype-dependent parameters are needed.

  11. Effects of foliar boron application on seed composition, cell wall boron, and seed δ15N and δ13C isotopes in water-stressed soybean plants

    Science.gov (United States)

    Bellaloui, Nacer; Hu, Yanbo; Mengistu, Alemu; Kassem, My A.; Abel, Craig A.

    2013-01-01

    Limited information is available on the effects of foliar boron (B) application on soybean seed composition. The objective of this research was to investigate the effects of foliar B on seed composition (protein, oil, fatty acids, and sugars). Our hypothesis was that since B is involved in nitrogen and carbon metabolism, it may impact seed composition. A repeated greenhouse experiment was conducted where half of the soybean plants was exposed to water stress (WS) and the other half was well-watered. Foliar boron (FB) in the form of boric acid was applied twice at a rate of 1.1 kg ha−1. The first application was during flowering stage, and the second application was during seed-fill stage. Treatments were water stressed plants with no FB (WS–B); water stressed plants with FB (WS+B); watered plants without FB (W–B), and watered plants with FB (W+B). The treatment W–B was used as a control. Comparing with WS–B plants, B concentration was the highest in leaves and seed of W+B plants (84% increase in leaves and 73% in seed). Seeds of W+B plants had higher protein (11% increase), oleic acid (27% increase), sucrose (up to 40% increase), glucose, and fructose comparing with W–B. However, seed stachyose concentrations increased by 43% in WS–B plants seed compared with W–B plants. Cell wall (structural) B concentration in leaves was higher in all plants under water stress, especially in WS–B plants where the percentage of cell wall B reached up to 90%. Water stress changed seed δ15N and δ13C values in both B applied and non-B applied plants, indicating possible effects on nitrogen and carbon metabolism. This research demonstrated that FB increased B accumulation in leaves and seed, and altered seed composition of well-watered and water stressed plants, indicating a possible involvement of B in seed protein, and oleic and linolenic fatty acids. Further research is needed to explain mechanisms of B involvement in seed protein and fatty acids. PMID:23888163

  12. Effects of INH, DNP, 2, 4-D and CMU on the sugar content of the barley and maize leaves; Efecto de cuatro inhibidores metabolicos (INH, DNP, 2, 3-D y CMU) sobre el contenido en azucares de hohas de cebada (Hordeum vulgare L.) y Maiz (Zea mais L.)

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J; Sancho, P

    1979-07-01

    1 ppm of the chemicals in nutritive solution was absorbed by barley and maize roots during 24 and 48 hours in dark or light conditioners in order to determine the best conditions. for the obtention of labelled sugars with high specific activity. Results show that the highest specific activity was obtained In maize plants treated with DNP for 24 hours in dark conditions. (Author) 51 refs.

  13. Fungal growth during malting of barley

    Directory of Open Access Journals (Sweden)

    Kocić-Tanackov Sunčica D.

    2005-01-01

    Full Text Available Fungi were isolated and identified in two samples of winter two-row barley (SSK3 and SSK6 harvested in 2003, Kragujevac location, during micromalting. Fungi were isolated and identified in barley before the micromalting, after the 1st, 2nd and 3rd day of steeping, the first day and after the germination after kilning and after malt degermination. The total fungi count was followed in both barley samples, during the mentioned phases. The total count of fungi was also determined in the steeping water, and the isolation and identification was performed after the steeping process. Change of the total count of fungi during barley micromalting was exponentional. During barley micromalting nine fungi genera were isolated: Phoma, Alternaria, Fusarium aspergillus, Cladosporium, Geotrichum, Scopulariopsis, Aureobasidium and Mucor. The most frequent genera were: Phoma, Alternaria and Fusarium. In water for steeping, five genera were identified: Geotrichum, Fusarium, Phoma Cladosporium and Mucor. The most frequent genera was Phoma.

  14. Comparative Study on the Effect of Water Stress and Rootstock on Photosynthetic Function in Pistachio (Pistacia vera L. Trees

    Directory of Open Access Journals (Sweden)

    Abolfazl Ranjbar

    2017-12-01

    Full Text Available The aim of this study is to evaluate the  effects of water deficit stress on chlorophyll fluorescence (CF characteristics of photosystem II (PSII and pigment contents in two rootstock seedlings (Pistacia atlantica L. and P. khinjuk L.. Three levels of soil water potential (Ψs was used, including WWD (-0.05 MPa, MWD (-0.7 MPa and SWD (-1.5 MPa. It was found that water stress increased the minimal fluorescence (F0, quantum yield baseline (F0/Fm and decreased the maximal fluorescence (Fm and maximum quantum yield of PSII photochemistry (Fv/Fm parameters in dark adapted leaves. In light adapted leaves, a significant increase in non-photochemical quenching (NPQ and thermal dissipation of light energy to heat (D and a decrease in electron transport rate (ETR and photochemical efficiency of photosystem II (ΦPSII occurred. The results demonstrated a decline in photosynthetic pigments (Chla, (Chlb and carotenoids (Car content with increasing water stress, whereas there was no significant effect on Chl (a/b and Car/(a+b ratios. Our data revealed there was no different in terms of performance between the two rootstocks in the alteration rate of pigment contents and photosynthetic features against soil water deficit conditions.

  15. Detecting and monitoring water stress states in maize crops using spectral ratios obtained in the photosynthetic domain

    Science.gov (United States)

    Baranoski, Gladimir V. G.; Van Leeuwen, Spencer R.

    2017-07-01

    The reliable detection and monitoring of changes in the water status of crops composed of plants like maize, a highly adaptable C4 species in large demand for both food and biofuel production, are longstanding remote sensing goals. Existing procedures employed to achieve these goals rely predominantly on the spectral signatures of plant leaves in the infrared domain where the light absorption within the foliar tissues is dominated by water. It has been suggested that such procedures could be implemented using subsurface reflectance to transmittance ratios obtained in the visible (photosynthetic) domain with the assistance of polarization devices. However, the experiments leading to this proposition were performed on detached maize leaves, which were not influenced by the whole (living) plant's adaptation mechanisms to water stress. In this work, we employ predictive simulations of light-leaf interactions in the photosynthetic domain to demonstrate that the living specimens' physiological responses to dehydration stress should be taken into account in this context. Our findings also indicate that a reflectance to transmittance ratio obtained in the photosynthetic domain at a lower angle of incidence without the use of polarization devices may represent a cost-effective alternative for the assessment of water stress states in maize crops.

  16. The role of water channel proteins in facilitating recovery of leaf hydraulic conductance from water stress in Populus trichocarpa.

    Directory of Open Access Journals (Sweden)

    Joan Laur

    Full Text Available Gas exchange is constrained by the whole-plant hydraulic conductance (Kplant. Leaves account for an important fraction of Kplant and may therefore represent a major determinant of plant productivity. Leaf hydraulic conductance (Kleaf decreases with increasing water stress, which is due to xylem embolism in leaf veins and/or the properties of the extra-xylary pathway. Water flow through living tissues is facilitated and regulated by water channel proteins called aquaporins (AQPs. Here we assessed changes in the hydraulic conductance of Populus trichocarpa leaves during a dehydration-rewatering episode. While leaves were highly sensitive to drought, Kleaf recovered only 2 hours after plants were rewatered. Recovery of Kleaf was absent when excised leaves were bench-dried and subsequently xylem-perfused with a solution containing AQP inhibitors. We examined the expression patterns of 12 highly expressed AQP genes during a dehydration-rehydration episode to identify isoforms that may be involved in leaf hydraulic adjustments. Among the AQPs tested, several genes encoding tonoplast intrinsic proteins (TIPs showed large increases in expression in rehydrated leaves, suggesting that TIPs contribute to reversing drought-induced reductions in Kleaf. TIPs were localized in xylem parenchyma, consistent with a role in facilitating water exchange between xylem vessels and adjacent living cells. Dye uptake experiments suggested that reversible embolism formation in minor leaf veins contributed to the observed changes in Kleaf.

  17. The role of water channel proteins in facilitating recovery of leaf hydraulic conductance from water stress in Populus trichocarpa.

    Science.gov (United States)

    Laur, Joan; Hacke, Uwe G

    2014-01-01

    Gas exchange is constrained by the whole-plant hydraulic conductance (Kplant). Leaves account for an important fraction of Kplant and may therefore represent a major determinant of plant productivity. Leaf hydraulic conductance (Kleaf) decreases with increasing water stress, which is due to xylem embolism in leaf veins and/or the properties of the extra-xylary pathway. Water flow through living tissues is facilitated and regulated by water channel proteins called aquaporins (AQPs). Here we assessed changes in the hydraulic conductance of Populus trichocarpa leaves during a dehydration-rewatering episode. While leaves were highly sensitive to drought, Kleaf recovered only 2 hours after plants were rewatered. Recovery of Kleaf was absent when excised leaves were bench-dried and subsequently xylem-perfused with a solution containing AQP inhibitors. We examined the expression patterns of 12 highly expressed AQP genes during a dehydration-rehydration episode to identify isoforms that may be involved in leaf hydraulic adjustments. Among the AQPs tested, several genes encoding tonoplast intrinsic proteins (TIPs) showed large increases in expression in rehydrated leaves, suggesting that TIPs contribute to reversing drought-induced reductions in Kleaf. TIPs were localized in xylem parenchyma, consistent with a role in facilitating water exchange between xylem vessels and adjacent living cells. Dye uptake experiments suggested that reversible embolism formation in minor leaf veins contributed to the observed changes in Kleaf.

  18. Alleviation of Water Stress Effects on MR220 Rice by Application of Periodical Water Stress and Potassium Fertilization

    Directory of Open Access Journals (Sweden)

    Nurul Amalina Mohd Zain

    2014-02-01

    Full Text Available The use of periodical water stress and potassium fertilization may enhance rice tolerance to drought stress and improve the crop’s instantaneous water use efficiency without much yield reduction. This study was conducted to assess the effects of different periodical water stress combined with potassium fertilization regimes on growth, yield, leaf gas exchanges and biochemical changes in rice grown in pots and compare them with standard local rice grower practices. Five treatments including (1 standard local grower’s practice (control, 80CF = 80 kg K2O/ha + control flooding; (2 120PW15 = 120 kg K2O/ha + periodical water stress for 15 days; (3 120DS15V = 120 kg K2O/ha + drought stress for 15 days during the vegetative stage; (4 120DS25V = 120 kg K2O/ha + drought stress for 25 days and (5 120DS15R = 120 kg K2O/ha + drought stress for 15 days during the reproductive stage, were evaluated in this experiment. Control and 120PW15 treatments were stopped at 100 DAS, and continuously saturated conditions were applied until harvest. It was found that rice under 120PW15 treatment showed tolerance to drought stress evidenced by increased water use efficiency, peroxidase (POX, catalase (CAT and proline levels, maximum efficiency of photosystem II (fv/fm and lower minimal fluorescence (fo, compared to other treatments. Path coefficient analysis revealed that most of parameters contribute directly rather than indirectly to rice yield. In this experiment, there were four factors that are directly involved with rice yield: grain soluble sugar, photosynthesis, water use efficiency and total chlorophyll content. The residual factors affecting rice yield are observed to be quite low in the experiment (0.350, confirming that rice yield was mostly influenced by the parameters measured during the study.

  19. Water stress detection in the Amazon using radar

    Science.gov (United States)

    van Emmerik, Tim; Steele-Dunne, Susan; Paget, Aaron; Oliveira, Rafael S.; Bittencourt, Paulo R. L.; Barros, Fernanda de V.; van de Giesen, Nick

    2017-07-01

    The Amazon rainforest plays an important role in the global water and carbon cycle, and though it is predicted to continue drying in the future, the effect of drought remains uncertain. Developments in remote sensing missions now facilitate large-scale observations. The RapidScat scatterometer (Ku band) mounted on the International Space Station observes the Earth in a non-Sun-synchronous orbit, which allows for studying changes in the diurnal cycle of radar backscatter over the Amazon. Diurnal cycles in backscatter are significantly affected by the state of the canopy, especially during periods of increased water stress. We use RapidScat backscatter time series and water deficit measurements from dendrometers in 20 trees during a 9 month period to relate variations in backscatter to increased tree water deficit. Morning radar bacskcatter dropped significantly with increased tree water deficit measured with dendrometers. This provides unique observational evidence that demonstrates the sensitivity of radar backscatter to vegetation water stress, highlighting the potential of drought detection and monitoring using radar.

  20. Water stress and harmful insects in agri-forest ecosystems

    Directory of Open Access Journals (Sweden)

    Mario Solinas

    2010-09-01

    Full Text Available Present knowledge on ecological services supplied by insects to natural terrestrial ecosystems, allow us to identify many homeostatic mechanisms regulating biological balance as well as life perpetuation of the said ecosystems; at the same time, that knowledge represents a sound referring point to understanding how those mechanisms do work so as to manage them in the anthropized ecosystems (i.e., agriculture and forests, and especially in order to identify in the latter the natural meaning of the so called insect outbreaks, so as to forecast and possibly prevent them; as well as, when needed, to conceive and formulate efficient control strategies having minimal environmental impact. Water factor is crucial with genesis, configuration and conservation of a terrestrial ecosystem (both natural or anthropized as a whole or in its individual components, but especially concerning plant life as well as plant interactions with phytophagous invertebrates, mainly insects. Insect-plant trophic interactions are principally influenced by the water conditions in the ecosystem, and the impact of phytophagous insects on crops is markedly affected. Extremely severe water stress, especially if prolonged, prevent insect life just like plant’s life but a moderate and not so prolonged water stress, while depressing plant vigour, paradoxically can improve development and multiplication of phytophagous arthropods, with severe consequences on woody plants especially, and forest trees markedly.

  1. Water stress and harmful insects in agri-forest ecosystems

    Directory of Open Access Journals (Sweden)

    Mario Solinas

    2011-02-01

    Full Text Available Present knowledge on ecological services supplied by insects to natural terrestrial ecosystems, allow us to identify many homeostatic mechanisms regulating biological balance as well as life perpetuation of the said ecosystems; at the same time, that knowledge represents a sound referring point to understanding how those mechanisms do work so as to manage them in the anthropized ecosystems (i.e., agriculture and forests, and especially in order to identify in the latter the natural meaning of the so called insect outbreaks, so as to forecast and possibly prevent them; as well as, when needed, to conceive and formulate efficient control strategies having minimal environmental impact. Water factor is crucial with genesis, configuration and conservation of a terrestrial ecosystem (both natural or anthropized as a whole or in its individual components, but especially concerning plant life as well as plant interactions with phytophagous invertebrates, mainly insects. Insect-plant trophic interactions are principally influenced by the water conditions in the ecosystem, and the impact of phytophagous insects on crops is markedly affected. Extremely severe water stress, especially if prolonged, prevent insect life just like plant’s life but a moderate and not so prolonged water stress, while depressing plant vigour, paradoxically can improve development and multiplication of phytophagous arthropods, with severe consequences on woody plants especially, and forest trees markedly.

  2. Water stress and harmful insects in agri-forest ecosystems

    Directory of Open Access Journals (Sweden)

    Mario Solinas

    Full Text Available Present knowledge on ecological services supplied by insects to natural terrestrial ecosystems, allow us to identify many homeostatic mechanisms regulating biological balance as well as life perpetuation of the said ecosystems; at the same time, that knowledge represents a sound referring point to understanding how those mechanisms do work so as to manage them in the anthropized ecosystems (i.e., agriculture and forests, and especially in order to identify in the latter the natural meaning of the so called insect outbreaks, so as to forecast and possibly prevent them; as well as, when needed, to conceive and formulate efficient control strategies having minimal environmental impact. Water factor is crucial with genesis, configuration and conservation of a terrestrial ecosystem (both natural or anthropized as a whole or in its individual components, but especially concerning plant life as well as plant interactions with phytophagous invertebrates, mainly insects. Insect-plant trophic interactions are principally influenced by the water conditions in the ecosystem, and the impact of phytophagous insects on crops is markedly affected. Extremely severe water stress, especially if prolonged, prevent insect life just like plant’s life but a moderate and not so prolonged water stress, while depressing plant vigour, paradoxically can improve development and multiplication of phytophagous arthropods, with severe consequences on woody plants especially, and forest trees markedly.

  3. Esterase Isoenzyme Variants in Barley

    DEFF Research Database (Denmark)

    Hvid, S.; Nielsen, G.

    1977-01-01

    Gene symbols are proposed for 27 esterase isoenzyme alleles representing 10 loci in barley. Two new esterase loci, Est 9 and Est 10, each with an active and a silent allele, and three new alleles in previously described loci were found. A few chemical and physical characteristics of the different...... esterase isoenzyme systems were studied. The heat inactivation temperature differed for the isoenzymes coded by most of the loci, whereas the substrate and inhibitor specificity of the isoenzymes was less distinct. A possible relationship between some of the systems is discussed....

  4. Resistance to Barley Leaf Stripe

    DEFF Research Database (Denmark)

    Nørgaard Knudsen, J. C.

    1986-01-01

    in well adapted Northwest European spring cultivars. Virulence matching two hitherto not overcome resistances was demonstrated. Differences in apparent race nonspecific or partial resistance were also present, changing the percentage of infected plants of susceptible genotypes from about 20 to 44 per cent.......Ten barley [Hordeum vulgare] genotypes were inoculated with twelve isolates of Pyrenophora graminea of diverse European and North African origin. Race specific resistance occurred. Four, possibly five, genetically different sources of race-specific resistance were found, three of them occurring...

  5. Roles of Hydroxynitrile Glucosides in Barley

    DEFF Research Database (Denmark)

    Roelsgaard, Pernille Sølvhøj

    on barley (Hordeum vulgare). Barley accumulates five hydroxynitrile glucosides, including one cyanogenic glucoside, in the epidermal cell layer. Cyanogenic glucosides are classically known as hydrogen cyanide-releasing defense compounds which act against generalist insects and herbivores. However...... is proposed. The results obtained in this Ph.D. study provide a unique insight demonstrating that hydroxynitrile glucosides play a far more complex role in barley defense against and susceptibility to Bgh than previously described. Future studies can build on the platforms established in this study to provide...

  6. Cowpea bean production under water stress using hydrogels

    Directory of Open Access Journals (Sweden)

    Marília Barcelos Souza Lopes

    2017-03-01

    Full Text Available The population increase and the need of intensifying food production, coupled with the scarcity of water resources, have led to the search of alternatives that reduce consumption and optimize the water use during cultivation. In this context, hydrogels become a strategy in agricultural management, due to their water retention capacity in the soil and availability to plants. This study aimed at evaluating the efficiency of hydrogels on the development and production of cowpea bean ('Sempre-verde' cultivar under water stress, in a greenhouse. The experiment was performed in a randomized block design, with five replications, in a 4 x 5 factorial scheme, consisting of four types of hydrogel (Hydroplan-EB HyA, with granulometry of 1-3 mm; Hydroplan-EB HyB, with granulometry of 0.5-1 mm; Hydroplan-EB HyC, with granulometry < 0.5 mm; Polim-Agri, with granulometry of 1-0.5 mm and five concentrations (0 g pot-1; 1.5 g pot-1; 3 g pot-1; 4.5 g pot-1; 6 g pot-1. The following traits were evaluated: number of pods per plant, number of grains per pod and grain yield. The highest concentration (6 g pot-1 resulted in a higher number of pods and yield for all the hydrogels, especially for HyC and Polim-Agro, which presented 7.4 pods plant-1 and 7.0 pods plant-1, with yield of 15.43 g plant-1 and 16.68 g plant-1, respectively. The use of hydrogel shows to be efficient for reducing yield losses under water stress.

  7. Net carbon allocation in soybean seedlings as influenced by soil water stress at two soil temperatures

    International Nuclear Information System (INIS)

    McCoy, E.L.; Boersma, L.; Ekasingh, M.

    1990-01-01

    The influence of water stress at two soil temperatures on allocation of net photoassimilated carbon in soybean (Glycine max [L.] Merr.) was investigated using compartmental analysis. The experimental phase employed classical 14 C labeling methodology with plants equilibrated at soil water potentials of -0.04, -0.25 and -0.50 MPa; and soil temperatures of 25 and 10C. Carbon immobilization in the shoot apex generally followed leaf elongation rates with decreases in both parameters at increasing water stress at both soil temperatures. However, where moderate water stress resulted in dramatic declines in leaf elongation rates, carbon immobilization rates were sharply decreased only at severe water stress levels. Carbon immobilization was decreased in the roots and nodules of the nonwater stressed treatment by the lower soil temperature. This relation was reversed with severe water stress, and carbon immobilization in the roots and nodules was increased at the lower soil temperature. Apparently, the increased demand for growth and/or carbon storage in these tissues with increased water stress overcame the low soil temperature limitations. Both carbon pool sizes and partitioning of carbon to the sink tissues increased with moderate water stress at 25C soil temperature. Increased pool sizes were consistent with whole plant osmotic adjustment at moderate water stress. Increased partitioning to the sinks was consistent with carbon translocation processes being less severely influenced by water stress than is photosynthesis

  8. MONITORING ON PLANT LEAF WATER POTENTIAL USING NIR SPECTROSCOPY FOR WATER STRESS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Diding Suhandy

    2012-12-01

    Full Text Available The performance of the calibration model with temperature compensation for on-plant leaf water potential (LWP determination in tomato plants was evaluated. During a cycle of water stress, the on-plant LWP measurement was conducted. The result showed that the LWP values under water stress and recovery from water stress could be monitored well. It showed that a real time monitoring of the LWP values using NIR spectroscopy could be possible.   Keywords: water stress, real time monitoring of leaf water potential, NIR spectroscopy, plant response-based

  9. SPRING BARLEY BREEDING FOR MALTING QUALITY

    Directory of Open Access Journals (Sweden)

    Alžbeta Žofajová

    2010-05-01

    Full Text Available The aim of this contribution is to illustrate the results of spring barley breeding for malting quality and point out an important position of variety in production of  qualitative  raw material for maltinq and beer  industry as well as the system of evaluation the qualitative parameters of breeding materials and adaptation of barley breeding programms to the  new requirements of  malting and beer industry. As an example of the results obtained most recently description is made of the Ezer, Levan, Donaris, Sladar spring barley varieties with very good malting quality and effective resistance to  powdery mildew.  Cultivation of these varieties  and malting barley production with  reduced use  of pesticidies is environmentally friedly alternative. doi:10.5219/50

  10. Detecting leaf pulvinar movements on NDVI time series of desert trees: a new approach for water stress detection.

    Directory of Open Access Journals (Sweden)

    Roberto O Chávez

    Full Text Available Heliotropic leaf movement or leaf 'solar tracking' occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI, should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern Chile, we studied seasonal and diurnal variations of MODIS and Landsat NDVI time series of plantation stands of the endemic species Prosopis tamarugo Phil., subject to different levels of groundwater depletion. As solar irradiation increased during the day and also during the summer, the paraheliotropic leaves of Tamarugo moved to an erectophile position (parallel to the sun rays making the NDVI signal to drop. This way, Tamarugo stands with no water stress showed a positive NDVI difference between morning and midday (ΔNDVI mo-mi and between winter and summer (ΔNDVI W-S. In this paper, we showed that the ΔNDVI mo-mi of Tamarugo stands can be detected using MODIS Terra and Aqua images, and the ΔNDVI W-S using Landsat or MODIS Terra images. Because pulvinar movement is triggered by changes in cell turgor, the effects of water stress caused by groundwater depletion can be assessed and monitored using ΔNDVI mo-mi and ΔNDVI W-S. For an 11-year time series without rainfall events, Landsat ΔNDVI W-S of Tamarugo stands showed a positive linear relationship with cumulative groundwater depletion. We conclude that both ΔNDVI mo-mi and ΔNDVI W-S have potential to detect early water stress of paraheliotropic vegetation.

  11. Detecting leaf pulvinar movements on NDVI time series of desert trees: a new approach for water stress detection.

    Science.gov (United States)

    Chávez, Roberto O; Clevers, Jan G P W; Verbesselt, Jan; Naulin, Paulette I; Herold, Martin

    2014-01-01

    Heliotropic leaf movement or leaf 'solar tracking' occurs for a wide variety of plants, including many desert species and some crops. This has an important effect on the canopy spectral reflectance as measured from satellites. For this reason, monitoring systems based on spectral vegetation indices, such as the normalized difference vegetation index (NDVI), should account for heliotropic movements when evaluating the health condition of such species. In the hyper-arid Atacama Desert, Northern Chile, we studied seasonal and diurnal variations of MODIS and Landsat NDVI time series of plantation stands of the endemic species Prosopis tamarugo Phil., subject to different levels of groundwater depletion. As solar irradiation increased during the day and also during the summer, the paraheliotropic leaves of Tamarugo moved to an erectophile position (parallel to the sun rays) making the NDVI signal to drop. This way, Tamarugo stands with no water stress showed a positive NDVI difference between morning and midday (ΔNDVI mo-mi) and between winter and summer (ΔNDVI W-S). In this paper, we showed that the ΔNDVI mo-mi of Tamarugo stands can be detected using MODIS Terra and Aqua images, and the ΔNDVI W-S using Landsat or MODIS Terra images. Because pulvinar movement is triggered by changes in cell turgor, the effects of water stress caused by groundwater depletion can be assessed and monitored using ΔNDVI mo-mi and ΔNDVI W-S. For an 11-year time series without rainfall events, Landsat ΔNDVI W-S of Tamarugo stands showed a positive linear relationship with cumulative groundwater depletion. We conclude that both ΔNDVI mo-mi and ΔNDVI W-S have potential to detect early water stress of paraheliotropic vegetation.

  12. Hydraulic properties of rice and the response of gas exchange to water stress.

    Science.gov (United States)

    Stiller, Volker; Lafitte, H Renee; Sperry, John S

    2003-07-01

    We investigated the role of xylem cavitation, plant hydraulic conductance, and root pressure in the response of rice (Oryza sativa) gas exchange to water stress. In the field (Philippines), the percentage loss of xylem conductivity (PLC) from cavitation exceeded 60% in leaves even in watered controls. The PLC versus leaf water potential relationship indicated diurnal refilling of cavitated xylem. The leaf water potential causing 50 PLC (P(50)) was -1.6 MPa and did not differ between upland versus lowland rice varieties. Greenhouse-grown varieties (Utah) were more resistant to cavitation with a 50 PLC of -1.9 MPa but also showed no difference between varieties. Six-day droughts caused concomitant reductions in leaf-specific photosynthetic rate, leaf diffusive conductance, and soil-leaf hydraulic conductance that were associated with cavitation-inducing water potentials and the disappearance of nightly root pressure. The return of root pressure after drought was associated with the complete recovery of leaf diffusive conductance, leaf-specific photosynthetic rate, and soil-leaf hydraulic conductance. Root pressure after the 6-d drought (61.2 +/- 8.8 kPa) was stimulated 7-fold compared with well-watered plants before drought (8.5 +/- 3.8 kPa). The results indicate: (a) that xylem cavitation plays a major role in the reduction of plant hydraulic conductance during drought, and (b) that rice can readily reverse cavitation, possibly aided by nocturnal root pressure.

  13. Cytosolic glutamine synthetase in barley

    DEFF Research Database (Denmark)

    Thomsen, Hanne Cecilie

    remobilisation from ageing plant parts. Thus, GS is highly involved in determining crop yield and NUE. The major objective of this PhD project was to investigate the NUE properties of transgenic barley designed to constitutively overexpress a GS1 isogene (HvGS1.1). These transgenic lines exhibited an increased...... for N demand. Of the GS isogenes, only the transcript levels of root HvGS1.1 increased when plants were transferred from high to low N. This change coincided with an increase in total GS activity. Pronounced diurnal variation was observed for root nitrate transporter genes and GS isogenes in both root...... fertilizer requirement. The enzyme glutamine synthetase (GS) has been a major topic in plant nitrogen research for decades due to its central role in plant N metabolism. The cytosolic version of this enzyme (GS1) plays an important role in relation to primary N assimilation as well as in relation to N...

  14. Nodule activity and allocation of photosynthate of soybean during recovery from water stress

    Science.gov (United States)

    Fellows, R. J.; Patterson, R. P.; Raper, C. D. Jr; Harris, D.; Raper CD, J. r. (Principal Investigator)

    1987-01-01

    Nodulated soybean plants (Glycine max [L.] Merr. cv Ransom) in a growth-chamber study were subjected to a leaf water potential (psi w) of -2.0 megapascal during vegetative growth. Changes in nonstructural carbohydrate contents of leaves, stems, roots, and nodules, allocation of dry matter among plant parts, in situ specific nodule activity, and in situ canopy apparent photosynthetic rate were measured in stressed and nonstressed plants during a 7-day period following rewatering. Leaf and nodule psi w also were determined. At the time of maximum stress, concentration of nonstructural carbohydrates had declined in leaves of stressed, relative to nonstressed, plants, and the concentration of nonstructural carbohydrates had increased in stems, roots, and nodules. Sucrose concentrations in roots and nodules of stressed plants were 1.5 and 3 times greater, respectively, than those of nonstressed plants. Within 12 hours after rewatering, leaf and nodule psi w of stressed plants had returned to values of nonstressed plants. Canopy apparent photosynthesis and specific nodule activity of stressed plants recovered to levels for nonstressed plants within 2 days after rewatering. The elevated sucrose concentrations in roots and nodules of stressed plants also declined rapidly upon rehydration. The increase in sucrose concentration in nodules, as well as the increase of carbohydrates in roots and stems, during water stress and the rapid disappearance upon rewatering indicates that inhibition of carbohydrate utilization within the nodule may be associated with loss of nodule activity. Availability of carbohydrates within the nodules and from photosynthetic activity following rehydration of nodules may mediate the rate of recovery of N2-fixation activity.

  15. The strategy of carbon utilization in uniculm barley

    International Nuclear Information System (INIS)

    Gordon, A.J.; Ryle, G.J.A.; Powell, C.E.

    1977-01-01

    Following exposure of the youngest mature leaf of uniculm barley to 14 CO 2 , groups of plants were harvested over a 72 h period to determine the fate of 14 C in the photosynthesizing leaf and in growing leaves and roots. Initially, 14 C was mainly present in sucrose with a little in starch and charged compounds; transport out of the fed leaf was rapid and, by 7 and 24 h, 56 and 93% respectively of the 14 C had been translocated about equally to growing leaves and roots. Sucrose entering meristems was quickly metabolized to protein and structural carbohydrate (40 and 60% of the 14 C in these organs at 7 and 24 h respectively), while the remainder was converted to short-term storage products or intermediary metabolites. By the end of the first day c.35% of the 14 C originally assimilated had been lost in respiration. The metabolism of the leaf appeared to be organized on a diurnal basis, for it exported nearly all its carbon within 24 h of assimilation. In contrast, some of the assimilate imported into growing leaves and, to a lesser extent, roots was not immediately used for growth but persisted as temporary metabolites and was subsequently used for growth in the following days. (author)

  16. Antidepressant-like effects of young green barley leaf (Hordeum vulgare L.) in the mouse forced swimming test.

    Science.gov (United States)

    Yamaura, Katsunori; Nakayama, Noriyuki; Shimada, Maki; Bi, Yuanyuan; Fukata, Hideki; Ueno, Koichi

    2012-01-01

    Young green barley leaf is one of the richest sources of antioxidants and has been widely consumed for health management in Japan. In this study, we examined whether oral administration of young green barley leaf has an antidepressant effect on the forced swimming test in mice. Mice were individually forced to swim in an open cylindrical container, one hour after oral administration of young green barley leaf (400 or 1000 mg / kg) or imipramine (100 mg / kg). Expression of mRNA for nerve growth factor (NGF), brain-derived neurotrophic factor, and glucocorticoid receptor in the brain was analyzed using real-time quantitative polymerase chain reaction (PCR). There was a significant antidepressant-like effect in the forced swimming test; both 400 and 1000 mg / kg young green barley leaves, as well as the positive control imipramine (100 mg / kg), reduced the immobility duration compared to the vehicle group. The expression of mRNA for NGF detected in the hippocampus immediately after the last swimming test was higher than that in the non-swimming group (Nil). Oral administration of imipramine suppressed this increase to the level of the Nil group. Young green barley leaf (400 and 1000 mg / kg) also showed a moderate decrease in the expression of mRNA for NGF, in a dose-dependent manner. Oral administration of young green barley leaf is able to produce an antidepressant-like effect in the forced swimming test. Consequently it is possible that the antidepressant-like effects of the young green barley leaf are, at least in part, mediated by an inhibition of the increase in the hippocampus levels of NGF.

  17. Functional proteomics of barley and barley chloroplasts – strategies, methods and perspectives

    DEFF Research Database (Denmark)

    Petersen, Jørgen; Rogowska-Wrzesinska, Adelina; Jensen, Ole Nørregaard

    2013-01-01

    Barley (Hordeum vulgare) is an important cereal grain that is used in a range of products for animal and human consumption. Crop yield and seed quality has been optimized during decades by plant breeding programs supported by biotechnology and molecular biology techniques. The recently completed...... whole-genome sequencing of barley revealed approximately 26,100 open reading frames, which provides a foundation for detailed molecular studies of barley by functional genomics and proteomics approaches. Such studies will provide further insights into the mechanisms of, for example, drought and stress...... tolerance, micronutrient utilization, and photosynthesis in barley. In the present review we present the current state of proteomics research for investigations of barley chloroplasts, i.e., the organelle that contain the photosynthetic apparatus in the plant. We describe several different proteomics...

  18. Comparative leaf proteomics of drought-tolerant and -susceptible peanut in response to water stress

    Science.gov (United States)

    Water stress (WS) predisposes peanut plants to fungal infection resulting in pre-harvest aflatoxin contamination. Major changes during water stress including oxidative stress, lead to destruction of photosynthetic apparatus and other macromolecules within cells. Two peanut cultivars with diverse dro...

  19. Global monthly water stress: II. Water demand and severity of water

    NARCIS (Netherlands)

    Wada, Y.; Beek, L.P.H. van; Viviroli, D.; Dürr, H.H.; Weingartner, R.; Bierkens, M.F.P.

    2011-01-01

    This paper assesses global water stress at a finer temporal scale compared to conventional assessments. To calculate time series of global water stress at a monthly time scale, global water availability, as obtained from simulations of monthly river discharge from the companion paper, is confronted

  20. The crop water stress index (CWSI) for drip irrigated cotton in a semi ...

    African Journals Online (AJOL)

    The crop water stress index (CWSI) for drip irrigated cotton in a semi-arid region of Turkey. ... Four irrigation treatments designated as full (I100) with no water stress and slight (DI70), moderate (DI50) and strong water ... from 32 Countries:.

  1. Drought genetics have varying influence on corn water stress under differing water availability

    Science.gov (United States)

    Irrigated corn (Zea mays L.) in the Great Plains will be increasingly grown under limited irrigation management and greater water stress. Hybrids with drought genetics may decrease the impacts of water stress on yield. The objective of this experiment was to evaluate the effect of drought genetics o...

  2. The impacts of water stress on phloem transport in Douglas-fir trees

    Science.gov (United States)

    David Woodruff

    2014-01-01

    Despite the critical role that phloem plays in a number of plant functional processes and the potential impact of water stress on phloem structural and phloem sap compositional characteristics, little research has been done to examine how water stress influences phloem transport. The objectives of this study were to develop a more accurate understanding of how water...

  3. Infrared thermometry and the crop water stress index. I. History, theory, and baselines

    International Nuclear Information System (INIS)

    Gardner, B.R.; Nielsen, D.C.; Shock, C.C.

    1992-01-01

    Development of portable infrared thermometers and the definition of the Crop Water Stress Index (CWSI) have led to widespread interest in infrared thermometry to monitor water stress and schedule irrigations. But the CWSI concept is still new and poorly understood by many. The purpose of this paper is to review the definition of CWSI, and the determination and interpretation of the non-water-stressed baselines used to compute CWSI. The non-water-stressed baseline equation normalizes the canopy minus air temperature differential for variations in vapor pressure deficit. Non-water-stressed baselines can be determined empirically from measurements of canopy and air temperatures and vapor pressure deficit, made diurnally on a single day, or at a single time of day over many days, on well-watered plants. The value of the maximum canopy minus air temperature differential under maximum water stress should also be determined empirically. Causes for CWSI values falling outside of the defined 0 to 10 unit range are reviewed. Non-water-stressed baselines may shift with plant growth stage. Effective use of CWSI is dependent on understanding the definition of CWSI, and the proper determination and use of non-water-stressed baselines. (author)

  4. Response of Thematic Mapper bands to plant water stress

    Science.gov (United States)

    Cibula, W. G.; Zetka, E. F.; Rickman, D. L.

    1992-01-01

    Changes in leaf reflectance as water content decreases have been hypothesized to occur in the 1.55-1.75 and 2.08-2.35 micron wavelength regions. To evaluate this hypothesis, studies were conducted on ryegrass (Lolium multiflorum Lam.) and oats (Avena sativa L.), which were grown in a controlled, outdoor situation. Both fully-watered control beds and water-stressed beds were periodically examined with a spectroradiometer calibrated against a reflectance reference of polytetrafluoroethylene. The observed changes correspond to those predicted by stochastic leaf models employed by other investigators (leaf reflection increases in the 1.55-1.75 micron region as leaf water content decreases). Although the percentage changes in TM bands 1-3 are nearly as great as those found in TM bands 5 and 7, the absolute values of reflectance change are much lower. It is believed that these patterns are probably characteristic of a broad range of vegetation types. In terms of phenomena detection, these patterns should be considered in any practical remote sensing sensor scenario.

  5. Genomic Prediction of Seed Quality Traits Using Advanced Barley Breeding Lines

    Science.gov (United States)

    Nielsen, Nanna Hellum; Jahoor, Ahmed; Jensen, Jens Due; Orabi, Jihad; Cericola, Fabio; Edriss, Vahid; Jensen, Just

    2016-01-01

    Genomic selection was recently introduced in plant breeding. The objective of this study was to develop genomic prediction for important seed quality parameters in spring barley. The aim was to predict breeding values without expensive phenotyping of large sets of lines. A total number of 309 advanced spring barley lines tested at two locations each with three replicates were phenotyped and each line was genotyped by Illumina iSelect 9Kbarley chip. The population originated from two different breeding sets, which were phenotyped in two different years. Phenotypic measurements considered were: seed size, protein content, protein yield, test weight and ergosterol content. A leave-one-out cross-validation strategy revealed high prediction accuracies ranging between 0.40 and 0.83. Prediction across breeding sets resulted in reduced accuracies compared to the leave-one-out strategy. Furthermore, predicting across full and half-sib-families resulted in reduced prediction accuracies. Additionally, predictions were performed using reduced marker sets and reduced training population sets. In conclusion, using less than 200 lines in the training set can result in low prediction accuracy, and the accuracy will then be highly dependent on the family structure of the selected training set. However, the results also indicate that relatively small training sets (200 lines) are sufficient for genomic prediction in commercial barley breeding. In addition, our results indicate a minimum marker set of 1,000 to decrease the risk of low prediction accuracy for some traits or some families. PMID:27783639

  6. Genomic Prediction of Seed Quality Traits Using Advanced Barley Breeding Lines.

    Directory of Open Access Journals (Sweden)

    Nanna Hellum Nielsen

    Full Text Available Genomic selection was recently introduced in plant breeding. The objective of this study was to develop genomic prediction for important seed quality parameters in spring barley. The aim was to predict breeding values without expensive phenotyping of large sets of lines. A total number of 309 advanced spring barley lines tested at two locations each with three replicates were phenotyped and each line was genotyped by Illumina iSelect 9Kbarley chip. The population originated from two different breeding sets, which were phenotyped in two different years. Phenotypic measurements considered were: seed size, protein content, protein yield, test weight and ergosterol content. A leave-one-out cross-validation strategy revealed high prediction accuracies ranging between 0.40 and 0.83. Prediction across breeding sets resulted in reduced accuracies compared to the leave-one-out strategy. Furthermore, predicting across full and half-sib-families resulted in reduced prediction accuracies. Additionally, predictions were performed using reduced marker sets and reduced training population sets. In conclusion, using less than 200 lines in the training set can result in low prediction accuracy, and the accuracy will then be highly dependent on the family structure of the selected training set. However, the results also indicate that relatively small training sets (200 lines are sufficient for genomic prediction in commercial barley breeding. In addition, our results indicate a minimum marker set of 1,000 to decrease the risk of low prediction accuracy for some traits or some families.

  7. Radiosensitivities of cultured barley of different type (Hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan

    1990-01-01

    The dormant seeds (with 13% moisture) of 47 barley varieties were irradiated with various doses (0-40 krad) of 137 Cs γ-rays. The radiosensitivities of naked barley was significantly higher than that of hulled barley. The sensitive coefficients of seedling height were 0.04945 and 0.03667 for naked barley and hulled barley, respectively. The radiosensitivity of four-row naked barley was significantly higher than that of two-row hulled barley and six-row hulled barley. 47 varieties studied could be divided into five types with different radiosensitivities, i.e. extreme resistant, resistant, intermediate, sensitive and extreme sensitive. It was also found that the dose-effect curves of cell nucleus volume had a peal at 30 krad

  8. Ascorbic Acid Alleviates Water Stress in Young Peach Trees and Improves Their Performance after Rewatering

    Directory of Open Access Journals (Sweden)

    Consuelo Penella

    2017-09-01

    Full Text Available Exogenous application of biochemicals has been found to improve water stress tolerance in herbaceous crops but there are limited studies on deciduous fruit trees. The goal of this research was to study if ascorbic acid applications could improve physiological mechanisms associated with water stress tolerance in young fruit trees. Ascorbic acid was foliarly applied at a concentration of 250 ppm to water-stressed and well-watered peach trees (control of two cultivars (‘Scarletprince’ and ‘CaroTiger’. Trees received either one or two applications, and 1 week after the second application all trees were rewatered to field capacity. Upon rewatering, CO2 assimilation and stomatal conductance of water-stressed ‘Scarletprince’ trees sprayed with ascorbic acid (one or two applications were similar to those of well-irrigated trees, but water-stressed trees that had not received ascorbic acid did not recover photosynthetical functions. Also, water status in sprayed water-stressed ‘Scarletprince’ trees was improved to values similar to control trees. On the other hand, water-stressed ‘CaroTiger’ trees needed two applications of ascorbic acid to reach values of CO2 assimilation similar to control trees but these applications did not improve their water status. In general terms, different response mechanisms to cope with water stress in presence of ascorbic acid were found in each cultivar, with ‘Scarletprince’ trees preferentially using proline as compatible solute and ‘CaroTiger’ trees relying on stomatal regulation. The application of ascorbic acid reduced cell membrane damage and increased catalase activity in water-stressed trees of both cultivars. These results suggest that foliar applications of ascorbic acid could be used as a management practice for improving water stress tolerance of young trees under suboptimal water regimes.

  9. Ascorbic Acid Alleviates Water Stress in Young Peach Trees and Improves Their Performance after Rewatering.

    Science.gov (United States)

    Penella, Consuelo; Calatayud, Ángeles; Melgar, Juan C

    2017-01-01

    Exogenous application of biochemicals has been found to improve water stress tolerance in herbaceous crops but there are limited studies on deciduous fruit trees. The goal of this research was to study if ascorbic acid applications could improve physiological mechanisms associated with water stress tolerance in young fruit trees. Ascorbic acid was foliarly applied at a concentration of 250 ppm to water-stressed and well-watered peach trees (control) of two cultivars ('Scarletprince' and 'CaroTiger'). Trees received either one or two applications, and 1 week after the second application all trees were rewatered to field capacity. Upon rewatering, CO 2 assimilation and stomatal conductance of water-stressed 'Scarletprince' trees sprayed with ascorbic acid (one or two applications) were similar to those of well-irrigated trees, but water-stressed trees that had not received ascorbic acid did not recover photosynthetical functions. Also, water status in sprayed water-stressed 'Scarletprince' trees was improved to values similar to control trees. On the other hand, water-stressed 'CaroTiger' trees needed two applications of ascorbic acid to reach values of CO 2 assimilation similar to control trees but these applications did not improve their water status. In general terms, different response mechanisms to cope with water stress in presence of ascorbic acid were found in each cultivar, with 'Scarletprince' trees preferentially using proline as compatible solute and 'CaroTiger' trees relying on stomatal regulation. The application of ascorbic acid reduced cell membrane damage and increased catalase activity in water-stressed trees of both cultivars. These results suggest that foliar applications of ascorbic acid could be used as a management practice for improving water stress tolerance of young trees under suboptimal water regimes.

  10. Combined Effects of Numerical Method Type and Time Step on Water Stressed Actual Crop ET

    Directory of Open Access Journals (Sweden)

    B. Ghahraman

    2016-02-01

    Full Text Available Introduction: Actual crop evapotranspiration (Eta is important in hydrologic modeling and irrigation water management issues. Actual ET depends on an estimation of a water stress index and average soil water at crop root zone, and so depends on a chosen numerical method and adapted time step. During periods with no rainfall and/or irrigation, actual ET can be computed analytically or by using different numerical methods. Overal, there are many factors that influence actual evapotranspiration. These factors are crop potential evapotranspiration, available root zone water content, time step, crop sensitivity, and soil. In this paper different numerical methods are compared for different soil textures and different crops sensitivities. Materials and Methods: During a specific time step with no rainfall or irrigation, change in soil water content would be equal to evapotranspiration, ET. In this approach, however, deep percolation is generally ignored due to deep water table and negligible unsaturated hydraulic conductivity below rooting depth. This differential equation may be solved analytically or numerically considering different algorithms. We adapted four different numerical methods, as explicit, implicit, and modified Euler, midpoint method, and 3-rd order Heun method to approximate the differential equation. Three general soil types of sand, silt, and clay, and three different crop types of sensitive, moderate, and resistant under Nishaboor plain were used. Standard soil fraction depletion (corresponding to ETc=5 mm.d-1, pstd, below which crop faces water stress is adopted for crop sensitivity. Three values for pstd were considered in this study to cover the common crops in the area, including winter wheat and barley, cotton, alfalfa, sugar beet, saffron, among the others. Based on this parameter, three classes for crop sensitivity was considered, sensitive crops with pstd=0.2, moderate crops with pstd=0.5, and resistive crops with pstd=0

  11. The breeding of new malting barley variety 'Yangpi No.2'

    International Nuclear Information System (INIS)

    Chen Xiulan; He Zhentian; Han Yuepeng; Wang Jinrong; Yang Hefeng

    2005-01-01

    'Yangpi No.2' barley pasted the examination of Jiangsu province in 2002, is the new spring two-rowed malting barley variety selected by which irradiation mutated the early-maturing of barley. The yield capacity of 'Yangpi No.2' barley is about 6750 kg/hm 2 , it had the characters of early-maturing, good agronomic characters, strong anti-adversity, high quality, and adapted well to everywhere in Jiangsu province. (authors)

  12. Boron-toxicity tolerance in barley arising from efflux transporter amplification.

    Science.gov (United States)

    Sutton, Tim; Baumann, Ute; Hayes, Julie; Collins, Nicholas C; Shi, Bu-Jun; Schnurbusch, Thorsten; Hay, Alison; Mayo, Gwenda; Pallotta, Margaret; Tester, Mark; Langridge, Peter

    2007-11-30

    Both limiting and toxic soil concentrations of the essential micronutrient boron represent major limitations to crop production worldwide. We identified Bot1, a BOR1 ortholog, as the gene responsible for the superior boron-toxicity tolerance of the Algerian barley landrace Sahara 3771 (Sahara). Bot1 was located at the tolerance locus by high-resolution mapping. Compared to intolerant genotypes, Sahara contains about four times as many Bot1 gene copies, produces substantially more Bot1 transcript, and encodes a Bot1 protein with a higher capacity to provide tolerance in yeast. Bot1 transcript levels identified in barley tissues are consistent with a role in limiting the net entry of boron into the root and in the disposal of boron from leaves via hydathode guttation.

  13. Sprouted barley for dairy cows: Nutritional composition and digestibility

    Science.gov (United States)

    A 4-unit dual-flow continuous culture fermentor system was used to assess the effect of supplementing 7-d sprouted barley or barley grain with an haylage or pasture diet on nutrient digestibility and methane output. Barley grain was sprouted in climate controlled growth chambers, to be used as part ...

  14. Amylolytic strains of Lactobacillus plantarum isolated from barley ...

    African Journals Online (AJOL)

    ... naturally present in barley, and produced cell-bound and cell-free α-amylase at alkaline conditions. The two strains may be developed into starter cultures to facilitate the germination of barley and produce malt with a higher fermentable sugar content. Key words: Lactobacillus plantarum, starch hydrolysis, barley, malting ...

  15. Phosphatidic acid, a versatile water-stress signal in roots

    Directory of Open Access Journals (Sweden)

    Fionn eMcLoughlin

    2013-12-01

    Full Text Available Adequate water supply is of utmost importance for growth and reproduction of plants. In order to cope with water deprivation, plants have to adapt their development and metabolism to ensure survival. To maximize water use efficiency, plants use a large array of signaling mediators such as hormones, protein kinases and phosphatases, Ca2+, reactive oxygen species and low abundant phospholipids that together form complex signaling cascades. Phosphatidic acid (PA is a signaling lipid that rapidly accumulates in response to a wide array of abiotic stress stimuli. PA formation provides the cell with spatial and transient information about the external environment by acting as a protein-docking site in cellular membranes. PA reportedly binds to a number of proteins that play a role during water limiting conditions, such as drought and salinity and has been shown to play an important role in maintaining root system architecture. Members of two osmotic stress-activated protein kinase families, sucrose non-fermenting 1-related protein kinase 2 (SnRK2 and mitogen activated protein kinases (MAPKs were recently shown bind PA and are also involved in the maintenance of root system architecture and salinity stress tolerance. In addition, PA regulates several proteins involved in abscisic acid (ABA-signaling. PA-dependent recruitment of glyceraldehyde-3-phosphate dehydrogenase (GAPDH under water limiting conditions indicates a role in regulating metabolic processes. Finally, a recent study also shows the PA recruits the clathrin heavy chain and a potassium channel subunit, hinting towards additional roles in cellular trafficking and potassium homeostasis. Taken together, the rapidly increasing number of proteins reported to interact with PA implies a broad role for this versatile signaling phospholipid in mediating salt and water stress responses.

  16. Infrared thermometry and the crop water stress index. II. Sampling procedures and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, B. R. [BP Research, Cleveland, OH (United States); Nielsen, D. C.; Shock, C. C.

    1992-10-15

    Infrared thermometry can be a valuable research and production tool for detecting and quantifying water stress in plants, as shown by a large volume of published research. Users of infrared thermometers (IRT) should be aware of the many equipment, environmental, and plant factors influencing canopy temperature measured by an IRT. The purpose of this paper is to describe factors influencing measured plant temperature, outline sampling procedures that will produce reliable Crop Water Stress Index (CWSI) values, and offer interpretations of CWSI and plant temperatures relative to crop production and other water stress parameters by reviewing previously conducted research. Factors that are considered are IRT condition, configuration, and position; psychrometer location; wind speed; solar radiation; time of day; leaf area and orientation; and appropriate non-water-stressed baseline equation. Standard sampling and CWSI calculation procedures are proposed. Use of CWSI with crops varying in type of response to water stress is described. Previously conducted research on plant temperatures or CWSI is tabulated by crop and water stress parameters measured. The paper provides valuable information to assist interested users of IRTs in making reliable water stress measurements. (author)

  17. Infrared thermometry and the crop water stress index. II. Sampling procedures and interpretation

    International Nuclear Information System (INIS)

    Gardner, B.R.; Nielsen, D.C.; Shock, C.C.

    1992-01-01

    Infrared thermometry can be a valuable research and production tool for detecting and quantifying water stress in plants, as shown by a large volume of published research. Users of infrared thermometers (IRT) should be aware of the many equipment, environmental, and plant factors influencing canopy temperature measured by an IRT. The purpose of this paper is to describe factors influencing measured plant temperature, outline sampling procedures that will produce reliable Crop Water Stress Index (CWSI) values, and offer interpretations of CWSI and plant temperatures relative to crop production and other water stress parameters by reviewing previously conducted research. Factors that are considered are IRT condition, configuration, and position; psychrometer location; wind speed; solar radiation; time of day; leaf area and orientation; and appropriate non-water-stressed baseline equation. Standard sampling and CWSI calculation procedures are proposed. Use of CWSI with crops varying in type of response to water stress is described. Previously conducted research on plant temperatures or CWSI is tabulated by crop and water stress parameters measured. The paper provides valuable information to assist interested users of IRTs in making reliable water stress measurements. (author)

  18. Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin.

    Science.gov (United States)

    Chamorro, D; Luna, B; Ourcival, J-M; Kavgacı, A; Sirca, C; Mouillot, F; Arianoutsou, M; Moreno, J M

    2017-01-01

    Mediterranean shrublands are generally water-limited and fire-driven ecosystems. Seed-based post-fire regeneration may be affected by varying rainfall patterns, depending on species sensitivity to germinate under water stress. In our study, we considered the germination response to water stress in four species from several sites across the Mediterranean Basin. Seeds of species with a hard coat (Cistus monspeliensis, C. salviifolius, Cistaceae, Calicotome villosa, Fabaceae) or soft coat (Erica arborea, Ericaceae), which were exposed or not to a heat shock and smoke (fire cues), were made to germinate under water stress. Final germination percentage, germination speed and viability of seeds were recorded. Germination was modelled using hydrotime analysis and correlated to the water balance characteristics of seed provenance. Water stress was found to decrease final germination in the three hard-seeded species, as well as reduce germination speed. Moreover, an interaction between fire cues and water stress was found, whereby fire cues increased sensitivity to water stress. Seed viability after germination under water stress also declined in two hard-seeded species. Conversely, E. arborea showed little sensitivity to water stress, independent of fire cues. Germination responses varied among populations of all species, and hydrotime parameters were not correlated to site water balance, except in E. arborea when not exposed to fire cues. In conclusion, the species studied differed in germination sensitivity to water stress; furthermore, fire cues increased this sensitivity in the three hard-seeded species, but not in E. arborea. Moreover, populations within species consistently differed among themselves, but these differences could only be related to the provenance locality in E. arborea in seeds not exposed to fire cues. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. A water stress index based on water balance modelling for discrimination of grapevine quality and yield

    Directory of Open Access Journals (Sweden)

    Rémi Gaudin

    2014-01-01

    Significance and impact of the study: This water stress index is a valuable tool for explaining the variations in grape yield and quality among various locations and years because it reflects the vineyard water stress history in relation to rainfall regime and soil conditions. Improvement would come from the simulation of FTSW during winter, notably for soils of high Total Transpirable Soil Water. One potential application is the quantification of water stress change brought by irrigation in Mediterranean vineyards, and its relation to grapevine production.

  20. SPRING BARLEY BREEDING FOR MALTING QUALITY

    OpenAIRE

    Alžbeta Žofajová; Jozef Gubiš; Ľudovít Sleziak; Klára Križanová; Vratislav Psota

    2010-01-01

    The aim of this contribution is to illustrate the results of spring barley breeding for malting quality and point out an important position of variety in production of  qualitative  raw material for maltinq and beer  industry as well as the system of evaluation the qualitative parameters of breeding materials and adaptation of barley breeding programms to the  new requirements of  malting and beer industry. As an example of the results obtained most recently descripti...

  1. Barley Transformation Using Agrobacterium-Mediated Techniques

    Science.gov (United States)

    Harwood, Wendy A.; Bartlett, Joanne G.; Alves, Silvia C.; Perry, Matthew; Smedley, Mark A.; Leyland, Nicola; Snape, John W.

    Methods for the transformation of barley using Agrobacterium-mediated techniques have been available for the past 10 years. Agrobacterium offers a number of advantages over biolistic-mediated techniques in terms of efficiency and the quality of the transformed plants produced. This chapter describes a simple system for the transformation of barley based on the infection of immature embryos with Agrobacterium tumefaciens followed by the selection of transgenic tissue on media containing the antibiotic hygromycin. The method can lead to the production of large numbers of fertile, independent transgenic lines. It is therefore ideal for studies of gene function in a cereal crop system.

  2. Barley seed proteomics from spots to structures

    DEFF Research Database (Denmark)

    Finnie, Christine; Svensson, Birte

    2009-01-01

    forms on 2D-gels. Specific protein families, including peroxidases and alpha-amylases have been subjected to in-depth analysis resulting in characterisation of different isozymes, post-translational. modifications and processing. A functional proteomics study focusing on the seed thioredoxin system has...... with information from rice and other cereals facilitate identification of barley proteins. Several hundred barley seed proteins are identified and lower abundance proteins including membrane proteins are now being analysed. In the present review we focus on variation in protein profiles of seed tissues during...

  3. The Effect of Water Stress and Polymer on Water Use Efficiency, Yield and several Morphological Traits of Sunflower under Greenhouse Condition

    Directory of Open Access Journals (Sweden)

    Hossein NAZARLI

    2010-12-01

    Full Text Available In many part of Iran, the reproductive growth stages of sunflower (Helianthus annuus L. are exposed to water deficit stress. Therefore, the investigation of irrigation management in the farm conditions is a necessary element for increasing irrigation efficiency and decreasing water losses. The objective of present study was to investigate the effect of different rates of super absorbent polymer and levels of water stress on water use efficiency (WUE, yield and some morphological traits of sunflower (cultivar Master. Factorial experiment was carried out in completely randomized design with 3 replications. Factors were water stress in three levels (irrigation in 0.75; 0.50 and 0.25% of field capacity and super absorbent polymer in five levels (0; 0.75; 0.150; 2.25; 3 g/kg of soil. Super absorbent polymer was added in eight leaves stage of sunflower to pots in deepness of roots development. Water stress treatment was also applied in this growth stage of sunflower. For stress application, pots were weighted every day and irrigated when soil water received to 0.75; 0.50 and 0.25 of field capacity, respectively. The results of ANOVA indicated that the effect of different rates of super absorbent polymer and different rates of consumed water in all traits were significant. ANOVA also revealed that the interactive effects of two mentioned factors were significant except for seed yield trait. Polynomial model based on the ANOVA results was fitted for each trait. The results indicated that water stress significantly convert in decreasing the number of leaves per plant, chlorophyll content, 100 weight of seeds, seed yield and WUE in sunflower, whereas the application of super absorbent polymer moderated the negative effect of deficit irrigation, especially in high rates of polymer (2.25 and 3 g/kg of soil. The above mentioned rates of polymer have the best effect to all characteristics of sunflower in all levels of water stress treatment. The findings

  4. Effects of ultraviolet-B radiation on plants during mild water stress, 4: The insensitivity of soybean internal water relations to ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Teramura, A.H.; Forseth, I.N.; Lydon, J.

    1984-01-01

    The combined effects of ultraviolet-B (UV-B, 280–320 nm) radiation and water stress were investigated on the water relations of greenhouse grown soybean [Glycine max (L.) Merr. cv. Essex]. On a weighted (Caldwell 1971), total daily dose basis, plants received either 0 or 3 000 effective J m 2 UV-B BE supplied by filtered FS-40 sunlamps. The latter dose simulated the solar UV-B radiation anticipated at College Park, Maryland, U.S.A. (39°N latitude) in the event that the global stratospheric ozone column is reduced by 25%. Plants were either well-watered or preconditioned by drought stress cycles. Diurnal measurements of water potential and stomatal conductance were made on the youngest fully expanded leaf. Various internal water relations parameters were determined for detached leaves. Plants were monitored before, during and after water stress. There were no significant differences in leaf water potential or stomatal conductance between treatments before plants were preconditioned to water stress. However, drought stress resulted in significantly lower midday and afternoon leaf water potentials and lower leaf conductances as compared to well-watered plants. UV-B radiation had no additional effect on leaf water potential; however, UV did result in lower leaf conductances in plants preconditioned to water stress. Turgid weight:dry weight ratio, elastic modulus, bound water and relative water content were unaffected by UV-B radiation. Osmotic potentials at full and zero turgor were significantly lower in the drought stressed treatments as compared to well-watered plants. (author)

  5. Effect of water stress on in vitro mycelium cultures of two mycorrhizal desert truffles.

    Science.gov (United States)

    Navarro-Ródenas, Alfonso; Lozano-Carrillo, M Cecilia; Pérez-Gilabert, Manuela; Morte, Asunción

    2011-05-01

    The ability of two species of desert truffle, Terfezia claveryi strain TcS2 and Picoa lefebvrei strain OL2, to tolerate water stress in pure culture has been investigated. Both T. claveryi and P. lefebvrei strains exhibited a mycelium growth pattern characteristic of drought tolerant species. However, they were only tolerant to moderate water stress, below -1.07 MPa, with the P. lefebvrei isolate being slightly more drought tolerant than the T. claveryi isolate. The increased alkaline phosphatase (ALP) activity observed in both fungi at moderate water stress with respect to the control indicated the functional adaptation of these mycelia to these drought conditions. ALP activity can be used as an indicator of the metabolic activity of these fungi. Slight water stress (-0.45 MPa) could improve mycelial inoculum production of these desert truffles. Moreover, P. lefebvrei could be a good candidate for further desert truffle mycorrhizal plant cultivation programmes in semiarid Mediterranean areas.

  6. Effects of water stress on germination of Pinus nigra Arnold. seeds

    International Nuclear Information System (INIS)

    Topacoglu, O.; Sevik, H.; Akkuzu, E.

    2016-01-01

    Climate change, global warming and the deterioration of related environmental conditions cause an important problem for forest tree species. For this reason, it is necessary to determine the response of trees to these conditions. The Objective of this study was to investigate the effects of water stress on seed germination of fifteen Pinus nigra Arnold. provenances in Turkey. For this purpose, the water stresses between 0 and -8.0 bars were obtained using polyethylene glycol-6000 (PEG) solutions. Seeds were kept for 35 days at 20 ± 0.5 degree C. In this study, significant variations between the provenances were found. Ankara Uluhan ( percent 95, 08) and Isparta Tota ( percent 85, 41) provenances at -8.0 bars having the highest cumulative germination percentages were the most resistant provenances against the water stress. This study has shown that the water stress reduced the germination speed, germination percentage and germination value. (author)

  7. Effect of soil water stress on yield and proline content of four wheat ...

    African Journals Online (AJOL)

    Effect of soil water stress on yield and proline content of four wheat lines. ... This field study was conducted to evaluate the effect of drought stress after anthesis on proline accumulation and wheat yield during 2008 at ... from 32 Countries:.

  8. Occurrence of Rhynchosporium secalis (Oud. J.J. Davis on spring barley and winter rye in Finland

    Directory of Open Access Journals (Sweden)

    Kaiho Mäkelä

    1974-05-01

    Full Text Available This study was carried out on Rhynchosprium secalis (Oud. J. J. Davis occurring on spring barley, winter rye and couch grass (Agropyron repens (L. PB in Finland. The results were obtained from samples of barley (c. 860 samples and rye (c. 200 samples gathered in fields during the growing season throughout the country in 1971 1973. The samples (c. 170 samples of Agropyron repens were collected in fields and the borders of fields. The fungi of all the samples were examined by microscope and cultures and inocolation tests were used as well. Rhynchosporium secalis was observed to occur commonly on spring barley throughout the country from Helsinki to Lapland. The fungus was observed in about 30 per cent of the fields and in below 60 percent of the localities examined. Leaf blotch was commoner on six rowed barley than on two-rowed barley. The fungus sometimes attacked a field in great profusion. R. secalis was observed in below 50 per cent of the winter rye samples and in below 70 per cent of the localities examined. The fungus occurred commonly in the southern part of Finland and was found also in Lapland (Inari, 69° N, 27°E. Spores of the fungus were most abundant in the leaves of rye in spring and in early summer. R. secalis was observed rather scarce (in over 10 per cent of fields and in over 25 per cent of the localities examined on Agropyron repens throughout the country. A high degree of host specialisation has been found within the species R. secalis. Two isolates from spring barley and from winter rye were pathogenic to their original host only.

  9. Nitrogen Metabolism in Adaptation of Photosynthesis to Water Stress in Rice Grown under Different Nitrogen Levels

    Directory of Open Access Journals (Sweden)

    Chu Zhong

    2017-06-01

    Full Text Available To investigate the role of nitrogen (N metabolism in the adaptation of photosynthesis to water stress in rice, a hydroponic experiment supplying with low N (0.72 mM, moderate N (2.86 mM, and high N (7.15 mM followed by 150 g⋅L-1 PEG-6000 induced water stress was conducted in a rainout shelter. Water stress induced stomatal limitation to photosynthesis at low N, but no significant effect was observed at moderate and high N. Non-photochemical quenching was higher at moderate and high N. In contrast, relative excessive energy at PSII level (EXC was declined with increasing N level. Malondialdehyde and hydrogen peroxide (H2O2 contents were in parallel with EXC. Water stress decreased catalase and ascorbate peroxidase activities at low N, resulting in increased H2O2 content and severer membrane lipid peroxidation; whereas the activities of antioxidative enzymes were increased at high N. In accordance with photosynthetic rate and antioxidative enzymes, water stress decreased the activities of key enzymes involving in N metabolism such as glutamate synthase and glutamate dehydrogenase, and photorespiratory key enzyme glycolate oxidase at low N. Concurrently, water stress increased nitrate content significantly at low N, but decreased nitrate content at moderate and high N. Contrary to nitrate, water stress increased proline content at moderate and high N. Our results suggest that N metabolism appears to be associated with the tolerance of photosynthesis to water stress in rice via affecting CO2 diffusion, antioxidant capacity, and osmotic adjustment.

  10. Inhibition of barley grain germination by light

    NARCIS (Netherlands)

    Roth-Bejerano, N.; Meulen, R.M. van der; Wang, M.

    1996-01-01

    Intact grains of barley (Hordeum distichum cv. Triumph) germinated rapidly in the dark or when exposed to brief daily light breaks in the temperature range 15-25°C, although germination proceeded less rapidly at low temperatures. Prolonged illumination (16 h/day) or continuous light inhibited

  11. Barley Breeding for Quality Improvement in Tunisia

    African Journals Online (AJOL)

    TOSHIBA

    2012-11-06

    Nov 6, 2012 ... sub-humid environment at Beja and a semi-arid one at Kef. Heading date ... State of art showed that barley was a main food crop in. North Africa for ... rably to many other food grains (wheat, rye, and oats) and played a .... rates both analysis of variance (ANOVA) and principal component analysis (PCA) into ...

  12. Endoproteolytic activity assay in malting barley

    Directory of Open Access Journals (Sweden)

    Blanca Gómez Guerrero

    2013-12-01

    Full Text Available Hydrolysis of barley proteins into peptides and amino acids is one of the most important processes during barley germination.The degradation of the endosperm stored proteins facilitates water and enzyme movements, enhances modification, liberates starch granules and increases soluble amino nitrogen. Protease activity is the result of the activities of a mixture of exo- and endo-proteases. The barley proteins are initially solubilized by endo-proteases and the further by exo-proteases. Four classes of endo-proteases have been described: serine-proteases, cysteine-proteases, aspartic-proteases and metallo-proteases. The objective of this work was to develop a rapid and colorimetric enzymatic assay to determine the endo-proteolytic activity of the four endo-protease classes using two different substrates: azo-gelatin and azo-casein. Optimum conditions for the assays such as: pH,reaction time and temperature and absorbance scale were determined. Azo-gelatin presented several difficulties in standardizing an “in solution” assay. On the other hand, azo-casein allowed standardization of the assay for the four enzyme classes to produce consistent results. The endo-proteoteolytic method developed was applied to determine the endo-protease activity in barley, malt and wort.

  13. Chromosome aberration assays in barley (Hordeum vulgare)

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, M J [Univ. of Tennessee, Knoxville; Nilan, R A

    1982-01-01

    Barley is an exceellent organism for studies of induced chromosome aberrations because of its few (2n = 2x = 14) relatively large chromosomes. Root-tip and shoot-tip cells have been used extensively for the study of ionizing radiation-induced chromosome aberrations. The general procedures are well known, the technology is simple and easy to learn, and the assays are relatively quick and inexpensive. Both root tips and shoot tips can be used for the study of chemical mutagens as well as ionizing radiations. Pollen mother cells are well suited for studying the effects of mutagens on meiotic chromosomes. The literature review for the Gene-Tox Program reported on 61 chemicals tested for their effects on barley chromosomes. Of these, 90% were reported to be either positive or positive dose-related, while 7% were negative and 3% were questionable. Barley assays based on chromosomal aberrations are useful to detect the clastogenic potency of chemicals under laboratory conditions. Indications are that the data from barley can be used to corroborate data obtained from other organisms. Among the classes of chemicals assayed were: alcohols and phenols; alkaloids; epoxides; alkyl sulfates; amides and sulfonamides; aromatic amines; aryl halides; aziridines; alkenes; carbamates; hydroazides; nitroaromatics; nitrosamides; nitrosources; phenothiazines; and polycyclic aromatic hydrocarbons.

  14. The Barley Chromosome 5 Linkage Map

    DEFF Research Database (Denmark)

    Jensen, J.; Jørgensen, Jørgen Helms

    1975-01-01

    The literature is surveyed for data on recombination between loci on chromosome 5 of barley; 13 loci fall into the category “mapped” loci, more than 20 into the category “associated” loci and nine into the category “loci once suggested to be on chromosome 5”. A procedure was developed...

  15. Technical note: In situ ruminal starch disappearance kinetics of hull-less barley, hulled barley, and corn grains.

    Science.gov (United States)

    Ferreira, G; Yang, Y; Teets, C L; Brooks, W S; Griffey, C A

    2018-07-01

    The objective of this study was to compare ruminal starch disappearance rates of hull-less barley, hulled barley, and corn grains. Five different genotypes were used for each of the 2 barley types. In addition, each of these genotypes was grown in 2 different locations and years, resulting 10 independent barley samples for each of the 2 barley grain types. Five different genotypes of corn grain were obtained from a commercial seed company. After being ground to pass through a 4-mm screen of a cutter mill, 3.6 g of each grain was placed into a porous bag, which was then incubated in the rumen of 2 ruminally cannulated cows for 0, 4, 8, 12, 24, and 48 h. Corn grains had greater instant ruminal starch disappearances than barley grains (22.4 and 8.2%, respectively). Instant ruminal starch disappearances did not differ between hulled and hull-less barley grains. Ruminal starch fractional disappearance rates were greatest for hulled barley grains, moderate for hull-less barley grains, and lowest for corn grains (15.3, 13.9, and 7.1%/h, respectively). Ruminal starch half-life was shortest for hulled and hull-less barley grains (4.4 h) and longest for corn grains (6.6 h). Ruminal starch half-life did not differ between hulled barley and hull-less barley grains. In conclusion, using a holistic experimental design and statistical analysis, this study showed that starch from hull-less barley grains has a ruminal half-life similar to that of hulled barley grains and shorter than that of corn grains. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Barley yellow dwarf virus: Luteoviridae or Tombusviridae?

    Science.gov (United States)

    Miller, W Allen; Liu, Sijun; Beckett, Randy

    2002-07-01

    Summary Barley yellow dwarf virus (BYDV), the most economically important virus of small grains, features highly specialised relationships with its aphid vectors, a plethora of novel translation mechanisms mediated by long-distance RNA interactions, and an ambiguous taxonomic status. The structural and movement proteins of BYDV that confer aphid transmission and phloem-limitation properties resemble those of the Luteoviridae, the family in which BYDV is classified. In contrast, many genes and cis-acting signals involved in replication and gene expression most closely resemble those of the Tombusviridae. BYDV is in genus Luteovirus, family Luteoviridae. BYDV includes at least two serotypes or viruses: BYDV-PAV and BYDV-MAV. The former BYDV-RPV is now Cereal yellow dwarf virus-RPV (CYDV-RPV). CYDV is in genus Polerovirus, family Luteoviridae. Genus Luteovirus shares many features with family Tombusviridae. Physical properties: approximately 25 nm icosahedral (T = 3) virions. One major (22 kDa) and one minor (50-55 kDa) coat protein. 5.6-5.8 kb positive sense RNA genome with no 5'-cap and no poly(A) tail. Most grasses. Most important in oats, barley and wheat. Also infects maize and rice. Yellowing and dwarfing in barley, stunting in wheat; reddening, yellowing and blasting in oats. Some isolates cause leaf notching and curling. Key attractions: Model for the study of circulative transmission of aphid-transmitted viruses. Plethora of unusual translation mechanisms. Evidence of recombination in recent evolutionary history creates taxonomic ambiguity. Economically important virus of wheat, barley and oats, worldwide. Useful websites/meetings: International symposium: 'Barley Yellow Dwarf Disease: Recent Advances and Future Strategies', CIMMYT, El Batan, Mexico, 1-5 September 2002, http://www.cimmyt.cgiar.org/Research/wheat/Conf_BYD_02/invitation.htm http://www.cimmyt.org/Research/wheat/BYDVNEWS/htm/BYDVNEWS.htm Aphid transmission animation: http://www.ppws.vt.edu/~sforza/tmv/bydv_aph.html.

  17. Effect of Phosphorus Fertilizer and Water Stress on Protein and Phenolic Contents in Cotton (Gossypium Hirsutum L.)

    International Nuclear Information System (INIS)

    Abbas, Z.; Muhammad, S.; Murtaza, G.; Ahmad, I.; Shakeel, A.; Islam, M.; Ahmad, M.; Abdullah, M.

    2015-01-01

    Crop quality and production are affected by various fertilizers and water stress. In present research, the response of cotton variety CIM-496 to water stress and phosphorus fertilizer was investigated. Samples were collected after 90 days of planting. Kjeldahl method and thin layer chromatography (TLC) were used for the quantitative and qualitative analysis of total protein and phenolic compounds, respectively. Proteins were greatly affected by fertilizer treatment and water stress, but phenolic compounds remained unchanged upon fertilizer treatment. However, they were greatly affected by irrigation and water stress. Crop treated with 100 kg ha/sup -1/ P/sub 2/O/sub 5/ under water stress maintained high protein content as compared to unfertilized and no water stress treatments. However, phenolic compounds were found higher in fully irrigated plants as compared to water stress ones. Fertilizer treatments had no considerable effect on phenolic compounds. (author)

  18. High voltage electric field effects on structure and biological characteristics of barley seeds

    Energy Technology Data Exchange (ETDEWEB)

    Khazaei, J. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Agrotechnology, Univ. College of Abouraihan; Aliabadi, E. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Crop Production Horticulture, Univ. College of Aburaihan; Shayegani, A.A. [Tehran Univ., Tehran (Iran, Islamic Republic of). Univ. College of Engineering

    2010-07-01

    Electric biostimulation of seeds is a pre-sowing treatment in which an electric field is applied to seeds to increase germination of non standard seeds. This paper reported on a study that examined the effects of AC electric field and exposure time on the structure and biological characteristics of barley seeds. The objective was to determine the potential to accelerate seed germination, plant growth and root development by the electric field strength and exposure time. Makooei cultivar barley seeds were used in this study. The effect of electric field strength (at 2, 4, 9, and 14 kV/m) and exposure time (at 15, 45, 80, and 150 min) on seed germination was studied along with height of seedling, length or root, height of stem, length of leaves, earliness, dry weight and wet weight of seedling. The treated seeds were stored for a month in a refrigerator at 5 degrees C prior to the germination experiments. The initial germination percent of the seed was 81 per cent. The treatment of barley seeds in an AC electric field had a positive effect on all investigated parameters. The germination percent of the treated seed increased to 94.5 per cent . The seeds exposed for long periods of time (45 to 150 min) showed better germination than the seeds exposed to lower exposure times. Dry and wet weights of seedling increased 143.4 per cent and 45.7 per cent, respectively.

  19. Lipid and sugar profiles of various barley cultivars (Hordeum vulgare

    Directory of Open Access Journals (Sweden)

    Pastor Kristian A.

    2015-01-01

    Full Text Available The lipid components and soluble sugars in flour samples of different cultivars of barley (Hordeum vulgare, involving winter malting barley, winter forage barley, spring barley, and hulless barley, were identified. Fatty acids were extracted from flour samples with n-hexane, and derivatized into volatile methyl esters, using TMSH (trimethylsulfonium hydroxide in methanol. Soluble sugars were extracted from defatted and dried samples of barley flour with 96% ethanol, and further derivatized into the corresponding trimethylsilyl (TMS oximes, using hydroxylamine hydrochloride solution and BSTFA (N,O-bis-(trimethylsilyl-trifluoroacetamide. The hexane and alcoholic extracts of barley cultivars were analyzed by GC-MS system. Lipid and sugar compositions were very similar in all barley cultivars. Therefore, multivariate analysis was applied to numerical values of automatically integrated areas of the identified fatty acid methyl esters and TMS oximes of soluble sugars. The application of hierarchical cluster analysis showed a great similarity between the investigated flour samples of barley cultivars, according to their fatty acid content (0.96. Also, significant, but somewhat less similarity was observed regarding the content of soluble sugars (0.70. These preliminary results indicate the possibility of distinguishing flour made of barley, regardless of the variety, from flours made of other cereal species, just by the analysis of the contents of fatty acids and soluble sugars.[Projekat Ministarstva nauke Republike Srbije, br. TR 31066

  20. Studies on /sup 32/P transport and yellow rust resistance in barley

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, J. (Akademie der Landwirtschaftswissenschaften der DDR, Aschersleben. Inst. fuer Phytopathologie)

    1982-01-01

    Several cultivars of barley (Hordeum vulgare L.) differing in their resistance to yellow rust were used to study the influence of the infection with Puccinia striiformis West. (strain 24) on /sup 32/P transport in intact plants and isolated leaves. Close correlations exist between transport processes and resistance. For example, resistant plants seem to have a more intensive matter transport than susceptible ones. The importance of the rate of transport to the effectiveness of hypothetic inducers of resistance reactions and defence substances is discussed.

  1. Retardation of senescence by UV-A light in barley (Hordeum vulgare L.) leaf segments

    International Nuclear Information System (INIS)

    Cuello, J.; Sanchez, M.D.; Sabater, B.

    1994-01-01

    The effects of low intensity (0.9–2.2 W m −2 ) UV-A radiation on barley leaf senescence were investigated. UV-A inhibited chlorophyll loss and caused increases in membrane permeability and chloroplast endopeptidases associated with senescence. The treatment of leaf segments with UV-A changed the type of proteins synthesized by chloroplasts, stimulating the synthesis of some specific polypeptides. It is concluded that the senescence of detached leaves provides an appropriate system for investigating effects of low UV-A intensities which are probably mediated by synthesis of specific proteins. (author)

  2. Field assessment of partial resistance to powdery mildew in spring barley

    DEFF Research Database (Denmark)

    Nørgaard Knudsen, J. Chr.; Dalsgaard, H. H.; Jørgensen, Jørgen Helms

    1986-01-01

    Partial resistance to powdery mildew in spring barley was evaluated in three plot types: large isolation plots, in 1.4 m2 plots in chessboard design with guard plots of spring wheat and in single rows. Percentage leaf area covered by powdery mildew was scored four to six times during the season....... The relationship between single scores of amount of powdery mildew on the upper four leaves and the area under the disease progress curve was high in all plot designs during the first two to three weeks after heading, allowing selection for the trait by one or two scorings. Differential ranking of varieties...

  3. Foliar morphometric indicators for early detection of water stress in Gmelina arborea Roxb. in agroforestry systems of Santafé de Antioquia

    Directory of Open Access Journals (Sweden)

    Omar Melo-Cruz

    2012-12-01

    Full Text Available Leaf asymmetry was assessed in individuals of Gmelina arborea Roxb. growing under different soil water conditions in a dry forest agroforestry system (AFS, in Santafé de Antioquia. Leaf asymmetry was correlated with additional morphometric parameters, such as angle of insertion of the petiole in the leaf in mature individuals and the ratio of the number of teeth on the edge of the blade in juvenile leaves to propose new indicators of early stage stress. The models generated had R2 values of above 75 %, which support their use in identifying developmental instability as an early indicator of water stress. Similarly, leaf diversity was assessed between the two phenotypes of leaves (ML and JL, with conventional morphometric variables (length of the midrib, leaf perimeter, specific leaf area and dry matter, because they are characters related to leaf form and function. There were marked differences in form and behavior between the two types of leaf indicating a further source of instability evident from leaf ontogeny. The results of this work will allow the optimization of management strategies of G. arborea in the AFS as an early indicator of water stress.

  4. The cis-regulatory element CCACGTGG is involved in ABA and water-stress responses of the maize gene rab28.

    Science.gov (United States)

    Pla, M; Vilardell, J; Guiltinan, M J; Marcotte, W R; Niogret, M F; Quatrano, R S; Pagès, M

    1993-01-01

    The maize gene rab28 has been identified as ABA-inducible in embryos and vegetative tissues. It is also induced by water stress in young leaves. The proximal promoter region contains the conserved cis-acting element CCACGTGG (ABRE) reported for ABA induction in other plant genes. Transient expression assays in rice protoplasts indicate that a 134 bp fragment (-194 to -60 containing the ABRE) fused to a truncated cauliflower mosaic virus promoter (35S) is sufficient to confer ABA-responsiveness upon the GUS reporter gene. Gel retardation experiments indicate that nuclear proteins from tissues in which the rab28 gene is expressed can interact specifically with this 134 bp DNA fragment. Nuclear protein extracts from embryo and water-stressed leaves generate specific complexes of different electrophoretic mobility which are stable in the presence of detergent and high salt. However, by DMS footprinting the same guanine-specific contacts with the ABRE in both the embryo and leaf binding activities were detected. These results indicate that the rab28 promoter sequence CCACGTGG is a functional ABA-responsive element, and suggest that distinct regulatory factors with apparent similar affinity for the ABRE sequence may be involved in the hormone action during embryo development and in vegetative tissues subjected to osmotic stress.

  5. Simulating carbon dioxide exchange rates of deciduous tree species: evidence for a general pattern in biochemical changes and water stress response.

    Science.gov (United States)

    Reynolds, Robert F; Bauerle, William L; Wang, Ying

    2009-09-01

    Deciduous trees have a seasonal carbon dioxide exchange pattern that is attributed to changes in leaf biochemical properties. However, it is not known if the pattern in leaf biochemical properties - maximum Rubisco carboxylation (V(cmax)) and electron transport (J(max)) - differ between species. This study explored whether a general pattern of changes in V(cmax), J(max), and a standardized soil moisture response accounted for carbon dioxide exchange of deciduous trees throughout the growing season. The model MAESTRA was used to examine V(cmax) and J(max) of leaves of five deciduous trees, Acer rubrum 'Summer Red', Betula nigra, Quercus nuttallii, Quercus phellos and Paulownia elongata, and their response to soil moisture. MAESTRA was parameterized using data from in situ measurements on organs. Linking the changes in biochemical properties of leaves to the whole tree, MAESTRA integrated the general pattern in V(cmax) and J(max) from gas exchange parameters of leaves with a standardized soil moisture response to describe carbon dioxide exchange throughout the growing season. The model estimates were tested against measurements made on the five species under both irrigated and water-stressed conditions. Measurements and modelling demonstrate that the seasonal pattern of biochemical activity in leaves and soil moisture response can be parameterized with straightforward general relationships. Over the course of the season, differences in carbon exchange between measured and modelled values were within 6-12 % under well-watered conditions and 2-25 % under water stress conditions. Hence, a generalized seasonal pattern in the leaf-level physiological change of V(cmax) and J(max), and a standardized response to soil moisture was sufficient to parameterize carbon dioxide exchange for large-scale evaluations. Simplification in parameterization of the seasonal pattern of leaf biochemical activity and soil moisture response of deciduous forest species is demonstrated. This

  6. Gas exchange and hydraulics in seedlings of Hevea brasiliensis during water stress and recovery.

    Science.gov (United States)

    Chen, Jun-Wen; Zhang, Qiang; Li, Xiao-Shuang; Cao, Kun-Fang

    2010-07-01

    The response of plants to drought has received significant attention, but far less attention has been given to the dynamic response of plants during recovery from drought. Photosynthetic performance and hydraulic capacity were monitored in seedlings of Hevea brasiliensis under water stress and during recovery following rewatering. Leaf water relation, gas exchange rate and hydraulic conductivity decreased gradually after water stress fell below a threshold, whereas instantaneous water use efficiency and osmolytes increased significantly. After 5 days of rewatering, leaf water relation, maximum stomatal conductance (g(s-max)) and plant hydraulic conductivity had recovered to the control levels except for sapwood area-specific hydraulic conductivity, photosynthetic assimilation rate and osmolytes. During the phase of water stress, stomata were almost completely closed before water transport efficiency decreased substantially, and moreover, the leaf hydraulic pathway was more vulnerable to water stress-induced embolism than the stem hydraulic pathway. Meanwhile, g(s-max) was linearly correlated with hydraulic capacity when water stress exceeded a threshold. In addition, a positive relationship was shown to occur between the recovery of g(s-max) and of hydraulic capacity during the phase of rewatering. Our results suggest (i) that stomatal closure effectively reduces the risk of xylem dysfunction in water-stressed plants at the cost of gas exchange, (ii) that the leaf functions as a safety valve to protect the hydraulic pathway from water stress-induced dysfunction to a larger extent than does the stem and (iii) that the full drought recovery of gas exchange is restricted by not only hydraulic factors but also non-hydraulic factors.

  7. Including Effects of Water Stress on Dead Organic Matter Decay to a Forest Carbon Model

    Science.gov (United States)

    Kim, H.; Lee, J.; Han, S. H.; Kim, S.; Son, Y.

    2017-12-01

    Decay of dead organic matter is a key process of carbon (C) cycling in forest ecosystems. The change in decay rate depends on temperature sensitivity and moisture conditions. The Forest Biomass and Dead organic matter Carbon (FBDC) model includes a decay sub-model considering temperature sensitivity, yet does not consider moisture conditions as drivers of the decay rate change. This study aimed to improve the FBDC model by including a water stress function to the decay sub-model. Also, soil C sequestration under climate change with the FBDC model including the water stress function was simulated. The water stress functions were determined with data from decomposition study on Quercus variabilis forests and Pinus densiflora forests of Korea, and adjustment parameters of the functions were determined for both species. The water stress functions were based on the ratio of precipitation to potential evapotranspiration. Including the water stress function increased the explained variances of the decay rate by 19% for the Q. variabilis forests and 7% for the P. densiflora forests, respectively. The increase of the explained variances resulted from large difference in temperature range and precipitation range across the decomposition study plots. During the period of experiment, the mean annual temperature range was less than 3°C, while the annual precipitation ranged from 720mm to 1466mm. Application of the water stress functions to the FBDC model constrained increasing trend of temperature sensitivity under climate change, and thus increased the model-estimated soil C sequestration (Mg C ha-1) by 6.6 for the Q. variabilis forests and by 3.1 for the P. densiflora forests, respectively. The addition of water stress functions increased reliability of the decay rate estimation and could contribute to reducing the bias in estimating soil C sequestration under varying moisture condition. Acknowledgement: This study was supported by Korea Forest Service (2017044B10-1719-BB01)

  8. Chronic water stress reduces tree growth and the carbon sink of deciduous hardwood forests.

    Science.gov (United States)

    Brzostek, Edward R; Dragoni, Danilo; Schmid, Hans Peter; Rahman, Abdullah F; Sims, Daniel; Wayson, Craig A; Johnson, Daniel J; Phillips, Richard P

    2014-08-01

    Predicted decreases in water availability across the temperate forest biome have the potential to offset gains in carbon (C) uptake from phenology trends, rising atmospheric CO2 , and nitrogen deposition. While it is well established that severe droughts reduce the C sink of forests by inducing tree mortality, the impacts of mild but chronic water stress on forest phenology and physiology are largely unknown. We quantified the C consequences of chronic water stress using a 13-year record of tree growth (n = 200 trees), soil moisture, and ecosystem C balance at the Morgan-Monroe State Forest (MMSF) in Indiana, and a regional 11-year record of tree growth (n > 300 000 trees) and water availability for the 20 most dominant deciduous broadleaf tree species across the eastern and midwestern USA. We show that despite ~26 more days of C assimilation by trees at the MMSF, increasing water stress decreased the number of days of wood production by ~42 days over the same period, reducing the annual accrual of C in woody biomass by 41%. Across the deciduous forest region, water stress induced similar declines in tree growth, particularly for water-demanding 'mesophytic' tree species. Given the current replacement of water-stress adapted 'xerophytic' tree species by mesophytic tree species, we estimate that chronic water stress has the potential to decrease the C sink of deciduous forests by up to 17% (0.04 Pg C yr(-1) ) in the coming decades. This reduction in the C sink due to mesophication and chronic water stress is equivalent to an additional 1-3 days of global C emissions from fossil fuel burning each year. Collectively, our results indicate that regional declines in water availability may offset the growth-enhancing effects of other global changes and reduce the extent to which forests ameliorate climate warming. © 2014 John Wiley & Sons Ltd.

  9. Combining ability studies on yield related traits in wheat under normal and water stress conditions

    International Nuclear Information System (INIS)

    Saeed, A.; Khan, A.S.; Khaliq, I.

    2010-01-01

    Six diverse wheat cultivars/lines viz; Baviacore, Nesser, 9247, 9252, 9258 and 9267 were crossed in a complete diallel fashion to develop 30 F1 crosses, which were tested along with their parents under normal and water stress conditions. Numerical analysis was made for spike density, number of grains per spike, 100-grain weight, biological yield, grain yield and harvest index. Significant differences among genotypic mean were observed in all of the traits under both conditions. GCA and SCA differences were significant for all the traits under study except spike density and 100-grain weight in both conditions. Wheat variety Nesser showed maximum general combining ability value for spike density under water stress conditions and maximum GCA value for biological yield and grain yield under irrigated condition. The variety Baviacore proved best general combiner for number of grains per spike and harvest index under both conditions while biological yield and grain yield under water stress condition. Variety 9252 found best general combiner for 100-grain weight under both condition. The cross 9252 x Nesser showed maximum specific combining ability value for spike density and biological yield under irrigated while for 100-grain weight under water stress condition. 9258 x 9252 exhibited maximum SCA for number of grains per spike under irrigated while 9258 x Nesser under water stress condition. 9267 x Nesser showed maximum SCA for 100-grain weight under irrigated condition while spike density under water stress condition. 9258 x 9247 was proved best combiner for grain yield and harvest index irrigated while 9267 x 9258 for biological yield, grain yield and harvest index under water stress condition. (author)

  10. Abscisic Acid Accumulation by Roots of Xanthium strumarium L. and Lycopersicon esculentum Mill. in Relation to Water Stress 1

    Science.gov (United States)

    Cornish, Katrina; Zeevaart, Jan A. D.

    1985-01-01

    Plants of Xanthium strumarium L. and Lycopersicon esculentum Mill. cv `Rheinlands Ruhm' were grown in solution culture, and control and steam-girdled intact plants were stressed. Detached roots of both species were stressed to different extents in two ways: (a) either in warm air or, (b) in the osmoticum Aquacide III. The roots of both species produced and accumulated progressively more abscisic acid (ABA), the greater the stress inflicted by either method. ABA-glucose ester levels in Xanthium roots were not affected by water stress and were too low to be the source of the stress-induced ABA. The fact that ABA accumulated in detached roots and in roots of girdled plants proves that ABA was synthesized in the roots and not merely transported from the shoots. Maximum ABA accumulation in detached roots occurred after 60 to 70% loss of fresh weight. In Xanthium roots, ABA levels continued to increase for at least 11 hours, and no catabolism was apparent when stressed roots were immersed in water, although the roots did stop accumulating ABA. When osmotically stressed, Xanthium roots reached a maximum ABA level after 2 hours, but ABA continued to rise in the medium. Under optimal stress conditions, endogenous ABA levels increased 100 times over their prestress values in detached roots of Xanthium, and 15 times in Lycopersicon under nonoptimal stress, when endogenous ABA was expressed as concentrations based on tissue water content. These are much greater relative increases than observed in the leaves (15 times in Xanthium, 3 times in Lycopersicon), although the roots contain substantially less ABA than the leaves in all circumstances. The results suggest that the endogenous level of ABA in roots could rise appreciably prior to leaf wilt, and could modify the plant's water economy before the leaves become stressed. PMID:16664467

  11. Abscisic Acid Accumulation by Roots of Xanthium strumarium L. and Lycopersicon esculentum Mill. in Relation to Water Stress.

    Science.gov (United States)

    Cornish, K; Zeevaart, J A

    1985-11-01

    Plants of Xanthium strumarium L. and Lycopersicon esculentum Mill. cv ;Rheinlands Ruhm' were grown in solution culture, and control and steam-girdled intact plants were stressed. Detached roots of both species were stressed to different extents in two ways: (a) either in warm air or, (b) in the osmoticum Aquacide III. The roots of both species produced and accumulated progressively more abscisic acid (ABA), the greater the stress inflicted by either method. ABA-glucose ester levels in Xanthium roots were not affected by water stress and were too low to be the source of the stress-induced ABA. The fact that ABA accumulated in detached roots and in roots of girdled plants proves that ABA was synthesized in the roots and not merely transported from the shoots.Maximum ABA accumulation in detached roots occurred after 60 to 70% loss of fresh weight. In Xanthium roots, ABA levels continued to increase for at least 11 hours, and no catabolism was apparent when stressed roots were immersed in water, although the roots did stop accumulating ABA. When osmotically stressed, Xanthium roots reached a maximum ABA level after 2 hours, but ABA continued to rise in the medium.Under optimal stress conditions, endogenous ABA levels increased 100 times over their prestress values in detached roots of Xanthium, and 15 times in Lycopersicon under nonoptimal stress, when endogenous ABA was expressed as concentrations based on tissue water content. These are much greater relative increases than observed in the leaves (15 times in Xanthium, 3 times in Lycopersicon), although the roots contain substantially less ABA than the leaves in all circumstances. The results suggest that the endogenous level of ABA in roots could rise appreciably prior to leaf wilt, and could modify the plant's water economy before the leaves become stressed.

  12. Association mapping of partitioning loci in barley

    Directory of Open Access Journals (Sweden)

    Mackay Ian J

    2008-02-01

    Full Text Available Abstract Background Association mapping, initially developed in human disease genetics, is now being applied to plant species. The model species Arabidopsis provided some of the first examples of association mapping in plants, identifying previously cloned flowering time genes, despite high population sub-structure. More recently, association genetics has been applied to barley, where breeding activity has resulted in a high degree of population sub-structure. A major genotypic division within barley is that between winter- and spring-sown varieties, which differ in their requirement for vernalization to promote subsequent flowering. To date, all attempts to validate association genetics in barley by identifying major flowering time loci that control vernalization requirement (VRN-H1 and VRN-H2 have failed. Here, we validate the use of association genetics in barley by identifying VRN-H1 and VRN-H2, despite their prominent role in determining population sub-structure. Results By taking barley as a typical inbreeding crop, and seasonal growth habit as a major partitioning phenotype, we develop an association mapping approach which successfully identifies VRN-H1 and VRN-H2, the underlying loci largely responsible for this agronomic division. We find a combination of Structured Association followed by Genomic Control to correct for population structure and inflation of the test statistic, resolved significant associations only with VRN-H1 and the VRN-H2 candidate genes, as well as two genes closely linked to VRN-H1 (HvCSFs1 and HvPHYC. Conclusion We show that, after employing appropriate statistical methods to correct for population sub-structure, the genome-wide partitioning effect of allelic status at VRN-H1 and VRN-H2 does not result in the high levels of spurious association expected to occur in highly structured samples. Furthermore, we demonstrate that both VRN-H1 and the candidate VRN-H2 genes can be identified using association mapping

  13. Effects of green manure herbage management and its digestate from biogas production on barley yield, N recovery, soil structure and earthworm populations

    DEFF Research Database (Denmark)

    Frøseth, Randi Berland; Bakken, Anne Kjersti; Bleken, Marina Azzaroli

    2014-01-01

    management on the yield and N recovery of a subsequent spring barley crop, and their short term effects on soil structure and earthworm populations. A field trial was run from 2008 to 2011 at four sites with contrasting soils under cold climate conditions. We compared several options for on-site herbage......In repeatedly mown and mulched green manure leys, the mulched herbage contains substantial amounts of nitrogen (N), which may only slightly contribute to the following crops’ nutrient demand. The objective of the present work was to evaluate the effect of alternative strategies for green manure...... management and the application of anaerobically digested green manure herbage. Depending on the site, removal of green manure herbage reduced the barley grain yield by 0% to 33% compared to leaving it on-site. Applying digestate, containing 45% of the N in harvested herbage, as fertilizer for barley gave...

  14. Barley grain for ruminants: A global treasure or tragedy

    Directory of Open Access Journals (Sweden)

    Nikkhah Akbar

    2012-07-01

    Full Text Available Abstract Barley grain (Hordeum vulgare L. is characterized by a thick fibrous coat, a high level of ß-glucans and simply-arranged starch granules. World production of barley is about 30 % of that of corn. In comparison with corn, barley has more protein, methionine, lysine, cysteine and tryptophan. For ruminants, barley is the third most readily degradable cereal behind oats and wheat. Due to its more rapid starch fermentation rate compared with corn, barley also provides a more synchronous release of energy and nitrogen, thereby improving microbial nutrient assimilation. As a result, feeding barley can reduce the need for feeding protected protein sources. However, this benefit is only realized if rumen acidity is maintained within an optimal range (e.g., > 5.8 to 6.0; below this range, microbial maintenance requirements and wastage increase. With a low pH, microbial endotoxines cause pro-inflammatory responses that can weaken immunity and shorten animal longevity. Thus, mismanagement in barley processing and feeding may make a tragedy from this treasure or pearl of cereal grains. Steam-rolling of barley may improve feed efficiency and post-rumen starch digestion. However, it is doubtful if such processing can improve milk production and feed intake. Due to the need to process barley less extensively than other cereals (as long as the pericarp is broken, consistent and global standards for feeding and processing barley could be feasibly established. In high-starch diets, barley feeding reduces the need for capacious small intestinal starch assimilation, subsequently reducing hindgut starch use and fecal nutrient loss. With its nutritional exclusivities underlined, barley use will be a factual art that can either matchlessly profit or harm rumen microbes, cattle production, farm economics and the environment.

  15. Detection of Ustilago nuda (Jensen) Rostrup in winter barley seed

    OpenAIRE

    Ignjatov Maja; Petrović Dragana; Vujaković Milka; Taški-Ajduković Ksenija; Nikolić Zorica; Jovičić Dušica

    2011-01-01

    Barley is one of the most important cereals grown in our agroecological conditions. The causal agent of loose smut on barley Ustilago nuda (Jensen) Rostrup occurs frequently as varieties susceptible to this pathogen are present in the production. Disease symptoms are manifested on barley head (spike). Parasite is transmitted by seed (seedborne) and stays in the embryo tissue of the infected kernel as dormant mycelium. Recommended method for detection of U. nuda is given by ISTA Rules (method ...

  16. Free proline accumulation in leaves of cultivated plant species under water deficit conditions

    Directory of Open Access Journals (Sweden)

    Hanna Bandurska

    2013-12-01

    Full Text Available The effect of water deficit caused by soil drought on the content of free proline as well as the degree of cell membrane damages in the leaves of three cultivated plant species having different farm usefulness and water requirements have been studied. The used pIants were: poinsettia (Euphorbia pulcherrima Willd., 'Regina' and 'Cortez' grown for decorative purposes, a green vegetable of broccoli (Brassica oleracea var. botrytis, subvar. cymosa, 'Colonel' and 'Marathon' and a cereal plant of barley (the wild form Hordeum spontaneumm and Hordeum vulgaree 'Maresi'. The examined species differed in the size of the experienced stress. the Iargest RWC reduction was found iii broccoli leaves, while somewhat smaller - in barley. In poinsettia leaves, the reduction of RWC level was not large or did not occur at all. The accumulation of free proline in the species under study was also variable. The largest amount of this amino acid tended to accumulate in broccoli leaves, whereas the increase of its level took place only at a strong dehydration of tissues. The increase of proline level was smaller in barley leaves than in broccoli, but that was found already at a smalI dehydration of tissues. In poinsettia leaves, a several f`old increase of proline level was found at the early stage of the stress. The level of that amino acid gradually increased at consecutive times and did not depend on tissue dehydration. Damage of cell membranes amounted to 8.5-9.5% in barley leaves, about 3% in brocolli and to 0-2.6% in poinsettia. The role of proline in prevention of leaf dehydration and in alleviation of dehydration effects in the studied species has been discussed.

  17. The response of winter wheat to water stress and nitrogen fertilizer use efficiency

    International Nuclear Information System (INIS)

    Wang, F.; Qi, M.; Wang, H.; Changjiu, Z.

    1995-01-01

    The response of winter wheat to water stress imposed at different crop growth stages by deficit irrigation and fertilizer use under several schemes of irrigation were evaluated on fine sandy soil and sand loam soil. The results showed that according to grain yield response factor K, the order of sensitive growth stages of winter wheat to water stress in decreasing sequence were booting to flowering ( K= 0.90), winter afterward to booting ( K= 0.69), flowering to milking ( K= 0.44) and milking to ripening ( K= 0.25). Field water efficiency would get 16.7 kg/mm.ha when no water stress in growth period, and when water stress has occurred in some growth stages, the value of it decreased by 5 - 20 percent. It was also found that high fertilizer application rate without split application would not significantly influence the yield on fine sandy soil. But schedule of irrigation affected the translocation of nitrogen in the plant. When water stress occurred in later growth stage, the ratio of NUE in gain to straw decreased, and fertilizer was available for crop only about one month after fertilizer application, excessive fertilizer rate would result in decrease of NUE by leaching of nitrogen in sandy soil. Total recovery of fertilizer at harvest was half amount of application. 6 refs; 10 tabs; ( author)

  18. Responses to water stress of gas exchange and metabolites in Eucalyptus and Acacia spp.

    Science.gov (United States)

    Warren, Charles R; Aranda, Ismael; Cano, F Javier

    2011-10-01

    Studies of water stress commonly examine either gas exchange or leaf metabolites, and many fail to quantify the concentration of CO₂ in the chloroplasts (C(c)). We redress these limitations by quantifying C(c) from discrimination against ¹³CO₂ and using gas chromatography-mass spectrometry (GC-MS) for leaf metabolite profiling. Five Eucalyptus and two Acacia species from semi-arid to mesic habitats were subjected to a 2 month water stress treatment (Ψ(pre-dawn) = -1.7 to -2.3 MPa). Carbohydrates dominated the leaf metabolite profiles of species from dry areas, whereas organic acids dominated the metabolite profiles of species from wet areas. Water stress caused large decreases in photosynthesis and C(c), increases in 17-33 metabolites and decreases in 0-9 metabolites. In most species, fructose, glucose and sucrose made major contributions to osmotic adjustment. In Acacia, significant osmotic adjustment was also caused by increases in pinitol, pipecolic acid and trans-4-hydroxypipecolic acid. There were also increases in low-abundance metabolites (e.g. proline and erythritol), and metabolites that are indicative of stress-induced changes in metabolism [e.g. γ-aminobutyric acid (GABA) shunt, photorespiration, phenylpropanoid pathway]. The response of gas exchange to water stress and rewatering is rather consistent among species originating from mesic to semi-arid habitats, and the general response of metabolites to water stress is rather similar, although the specific metabolites involved may vary. © 2011 Blackwell Publishing Ltd.

  19. Interactions between biochar and mycorrhizal fungi in a water-stressed agricultural soil.

    Science.gov (United States)

    Mickan, Bede S; Abbott, Lynette K; Stefanova, Katia; Solaiman, Zakaria M

    2016-08-01

    Biochar may alleviate plant water stress in association with arbuscular mycorrhizal (AM) fungi but research has not been conclusive. Therefore, a glasshouse experiment was conducted to understand how interactions between AM fungi and plants respond to biochar application under water-stressed conditions. A twin chamber pot system was used to determine whether a woody biochar increased root colonisation by a natural AM fungal population in a pasture soil ('field' chamber) and whether this was associated with increased growth of extraradical AM fungal hyphae detected by plants growing in an adjacent ('bait') chamber containing irradiated soil. The two chambers were separated by a mesh that excluded roots. Subterranean clover was grown with and without water stress and harvested after 35, 49 and 63 days from each chamber. When biochar was applied to the field chamber under water-stressed conditions, shoot mass increased in parallel with mycorrhizal colonisation, extraradical hyphal length and shoot phosphorus concentration. AM fungal colonisation of roots in the bait chamber indicated an increase in extraradical mycorrhizal hyphae in the field chamber. Biochar had little effect on AM fungi or plant growth under well-watered conditions. The biochar-induced increase in mycorrhizal colonisation was associated with increased growth of extraradical AM fungal hyphae in the pasture soil under water-stressed conditions.

  20. Rehydration After Water Stress in Forager Workers of Coptotermes gestroi (Wasmann) (Blattaria: Rhinotermitidae).

    Science.gov (United States)

    Janei, V; Lima, J T; Costa-Leonardo, A M

    2015-06-01

    Water maintenance is vital for termite survival under dry conditions, hence environment humidity is one of the most important factors that controls the distribution of Isoptera. To understand the dynamics of termite rehydration after water loss, two bioassays were performed with forager workers of Coptotermes gestroi (Wasmann) submitted to water stress. Insects were weighed and placed into Petri dishes without water and food for periods of 3, 15, and 30 h. For each period of water stress, 10 replicates were performed in the treatment and control groups, totalling 120 experimental units. Forager workers lost body mass across all periods of water stress and tested with the highest reduction for the 30 h exposure period. Subsequent access to water resulted in termite rehydration, and final weight values were near to initial body mass values. These results demonstrate that workers of C. gestroi experienced large reductions of body mass under water stress, but these reductions were not severe enough to cause mortality. Additionally, termites were able to rehydrate after water stress conditions. This is a potential risk factor to be considered in cases of new infestations because C. gestroi workers will be able to cause economic damage in their new locations even when deprived of water during their transportation by humans.

  1. Water stress indices for the sugarcane crop on different irrigated surfaces

    Directory of Open Access Journals (Sweden)

    Rodrigo G. Brunini

    Full Text Available ABSTRACT Sugarcane (Saccharum officinarum L. is a crop of vital importance to Brazil, in the production of sugar and ethanol, power generation and raw materials for various purposes. Strategic information such as topography and canopy temperature can provide management technologies accessible to farmers. The objective of this study was to determine water stress indices for sugarcane in irrigated areas, with different exposures and slopes. The daily water stress index of the plants and the water potential in the soil were evaluated and the production system was analyzed. The experiment was carried out in an “Experimental Watershed”, using six surfaces, two horizontal and the other ones with 20 and 40% North and South exposure slopes. Water stress level was determined by measuring the temperatures of the vegetation cover and the ambient air. Watering was carried out using a drip irrigation system. The results showed that water stress index of sugarcane varies according to exposure and slope of the terrain, while areas whose water stress index was above 5.0 oC had lower yield values.

  2. Physical and virtual water transfers for regional water stress alleviation in China.

    Science.gov (United States)

    Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R; Guan, Dabo; Hubacek, Klaus

    2015-01-27

    Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management.

  3. Impacts of Climate Variability on the Spatio-temporal Characteristics of Water Stress in Korea

    Science.gov (United States)

    Kim, Soojun; Devineni, Naresh; Lall, Upmanu; Kim, Hung Soo

    2017-04-01

    This study intended to evaluate water stress quantitatively targeted at the Korean Peninsula and to analyze the spatial and temporal characteristics of its occurrence. First, the severity and multiyear influence of water stress were analyzed by realizing water balance based on water supply and demand and by calculating the normalized deficit index (NDI) and the normalized deficit cumulated (NDC) for 113 small basins in the Korean Peninsula. Next, a change in the periodic characteristics of water stress was analyzed using wavelet transform of the NDI by small basins and 3 bands of periods of 1 year, 2-4 years, and 4-8 years were separated. Through an analysis of the empirical orthogonal function (EOF) on each band, it was found that water stress occurring in the Korean Peninsula has the characteristics of spatial distribution that it is extended from the south coast to the northern area and inland as its period gets longer. An analysis of the band with a period of 2-8 years for water stress showed that it has a relationship with El Niño-Southern Oscillation (ENSO). Acknowledgment This research was supported by a grant (14AWMP-B082564-01) from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

  4. A flavonoid mutant of barley (Hordeum vulgare L.) exhibits increased sensitivity to UV-B radiation in the primary leaf

    International Nuclear Information System (INIS)

    Reuber, S.; Bornman, J.F.; Weissenböck, G.

    1996-01-01

    The aim of the present investigation was to define the role of soluble flavonoids as UV-B protectants in the primary leaf of barley (Hordeum vulgare L.). For this purpose we used a mutant line (Ant 287) from the Carlsberg collection of proanthocyanidin-free barley containing only 7% of total extractable flavonoids in the primary leaf as compared to the mother variety (Hiege 550/75). Seven-day-old leaves from plants grown under high visible light with or without supplementary UV-B radiation were used for the determination of UV-B sensitivity. UV-B-induced changes were assessed from parameters of chlorophyll fluorescence of photosystem II, including initial and maximum fluorescence, apparent quantum yield, and photochemical and non-photochemical quenching. A quartz fibre-optic microprobe was used to evaluate the amount of potentially harmful UV-B (310 nm radiation) penetrating into the leaf as a direct consequence of flavonoid deficiency. Our data indicate an essential role of flavonoids in UV-B protection of barley primary leaves. In leaves of the mutant line grown under supplementary UV-B, an increase in 310nm radiation in the mesophyll and a strong decrease in the quantum yield of photosynthesis were observed as compared to the corresponding mother variety. Primary leaves of liege responded to supplementary UV-B radiation with a 30% increase in the major flavonoid saponarin and a 500% increase in the minor compound lutonarin. This is assumed to be an efficient protective response since no changes in variable chlorophyll fluorescence were apparent. In addition, a further reduction in UV-B penetration into the mesophyll was recorded in these leaves

  5. Implementation of biochemical screening to improve baking quality of barley

    DEFF Research Database (Denmark)

    Vincze, Éva; Dionisio, Giuseppe; Aaslo, Per

    2011-01-01

    Barley (Hordeum vulgare) has the potential to offer considerable human nutritional benefits, especially as supplement to wheat-based breads. Under current commercial baking conditions it is not possible to introduce more that 20% barley flour to the wheat bread without negative impact on the phys......Barley (Hordeum vulgare) has the potential to offer considerable human nutritional benefits, especially as supplement to wheat-based breads. Under current commercial baking conditions it is not possible to introduce more that 20% barley flour to the wheat bread without negative impact...... on the physical chemical properties of the bread products due to the poor baking properties of barley flour. As a consequence, the nutritional advantages of barley are not fully exploited. The inferior leavening and baking properties of barley can, in part, be attributed to the physical properties of the storage...... proteins. Changing the storage protein composition can lessen this problem. Our working hypothesis was that exploiting the substantial genetic variation within the gene pool for storage proteins could enable improving the baking qualities of barley flour. We characterised forty-nine barley cultivars...

  6. Cisgenic barley with improved phytase activity

    DEFF Research Database (Denmark)

    Holme, Inger; Dionisio, Giuseppe; Brinch-Pedersen, Henrik

    2010-01-01

    copies of the genomic phytase gene and the selection gene to identify segregation between the two genes. Presently, we have identified two cisgenic T1 plants without vector backbone and selection gene but with an extra copy of the genomic phytase gene....... are accordingly very similar to those generated by conventional breeding. The cisgenesis concept allows for the introduction of extra gene copies of a particular gene to accentuate the trait. We are using a barley purple acid phosphatase expressed during grain filling as candidate gene for cisgenesis. A genomic...... barley lambda library has been used to isolate the genomic clone of this phytase including 2.3 kb of the promoter region and 600 bp of the terminator region. The clone has been inserted into a cisgenic Agrobacterium vector where both the gene of interest and the selection gene are flanked by their own T...

  7. Biosorption of nickel with barley straw.

    Science.gov (United States)

    Thevannan, Ayyasamy; Mungroo, Rubeena; Niu, Catherine Hui

    2010-03-01

    Wastewater containing nickel sulphate generated from a nickel plating industry is of great concern. In the present work, biosorption of nickel by barley straw from nickel sulphate solution was investigated. Nickel uptake at room temperature (23+/-0.5 degrees C) was very sensitive to solution pH, showing a better uptake value at a pH of 4.85+/-0.10 among the tested values. The nickel biosorption isotherm fitted well the Langmuir equation. When the ionic strength (IS) of the solution was increased from less than 0.02-0.6M, nickel uptake was reduced to 12% of that obtained at IS of less than 0.02 M. Barley straw showed a higher nickel uptake (0.61 mmol/g) than acid washed crab shells (0.04 mmol/g), demonstrating its potential as an adsorbent for removal of nickel. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  8. Implications of vegetation hydraulic capacitance as an indicator of water stress and drought recovery

    Science.gov (United States)

    Matheny, A. M.; Bohrer, G.

    2017-12-01

    Above-ground water storage in vegetation plays an integral role in the avoidance of hydraulic impairment to transpiration. New high temporal resolution measurements of dynamic changes in tree hydraulic capacitance are facilitating insights into vegetation water use strategies. Diurnal withdrawal from water storage in leaves, branches, stems, and roots significantly impacts sap flow, stomatal conductance, and transpiration. The ability to store and use water varies based on soil- and root-water availability, tree size, wood vessel anatomy and density, and stomatal response strategy (i.e. isohydricity). We present results from a three-year long study of stem capacitance dynamics in five species in a mixed deciduous forest in Michigan. The site receives 800mm of rainfall annually, but water potential in the well-drained sandy soil nears the permanent wilting point several times annually. We demonstrate radical differences in stored water use between drought tolerant and intolerant species. Red maple, a drought intolerant, isohydric species, showed a strong dependence on stem capacitance for transpiration during both wet and dry periods. Red oak, a more drought hearty, deep rooted, anisohydric species, was much less reliant on withdrawal from water storage during all conditions. During well-watered conditions, withdrawal from storage by red maple was 10 kg day-1, yet storage withdrawal from similarly sized red oaks was 1 kg day-1. Red oaks only drew strongly upon stored water during the driest extremes. Metrics of hydration status derived from capacitance provide a means to explore drought response and recovery. Declines in consecutive days' maximum capacitance indicate an inability to restore lost water and can be used to mark the onset of water stress. Drought recovery can be quantified as the time required for stem water content to return to pre-drought volumes. Capacitance withdrawal and depletion exhibit a clear threshold response to declining soil water

  9. A Comparison of Petiole Hydraulics and Aquaporin Expression in an Anisohydric and Isohydric Cultivar of Grapevine in Response to Water-Stress Induced Cavitation.

    Science.gov (United States)

    Shelden, Megan C; Vandeleur, Rebecca; Kaiser, Brent N; Tyerman, Stephen D

    2017-01-01

    We report physiological, anatomical and molecular differences in two economically important grapevine ( Vitis vinifera L.) cultivars cv. Grenache (near-isohydric) and Chardonnay (anisohydric) in their response to water-stress induced cavitation. The aim of the study was to compare organ vulnerability (petiole and stem) to cavitation by measuring ultrasonic acoustic emissions (UAE) and percent loss of conductance of potted grapevines subject to the onset of water-stress. Leaf (ψ L ) and stem water potential (ψ S ), stomatal conductance ( g s ), transpiration ( E ), petiole hydraulics ( K Pet ), and xylem diameter were also measured. Chardonnay displayed hydraulic segmentation based on UAE, with cavitation occurring at a less negative ψ L in the petiole than in the stem. Vulnerability segmentation was not observed in Grenache, with both petioles and stems equally vulnerable to cavitation. Leaf water potential that induced 50% of maximum UAE was significantly different between petioles and stems in Chardonnay (ψ 50Petiole = -1.14 and ψ 50Stem = -2.24 MPa) but not in Grenache (ψ 50Petiole = -0.73 and ψ 50Stem = -0.78 MPa). Grenache stems appeared more susceptible to water-stress induced cavitation than Chardonnay stems. Grenache displayed (on average) a higher K Pet likely due to the presence of larger xylem vessels. A close relationship between petiole hydraulic properties and vine water status was observed in Chardonnay but not in Grenache. Transcriptional analysis of aquaporins in the petioles and leaves ( VvPIP1;1, VvPIP2;1, VvPIP2;2 VvPIP2;3, VvTIP1;1 , and VvTIP2;1 ) showed differential regulation diurnally and in response to water-stress. VvPIP2;1 showed strong diurnal regulation in the petioles and leaves of both cultivars with expression highest predawn. Expression of VvPIP2;1 and VvPIP2;2 responded to ψ L and ψ S in both cultivars indicating the expression of these two genes are closely linked to vine water status. Expression of several aquaporin

  10. Transgenic Wheat, Barley and Oats: Future Prospects

    Science.gov (United States)

    Dunwell, Jim M.

    Following the success of transgenic maize and rice, methods have now been developed for the efficient introduction of genes into wheat, barley and oats. This review summarizes the present position in relation to these three species, and also uses information from field trial databases and the patent literature to assess the future trends in the exploitation of transgenic material. This analysis includes agronomic traits and also discusses opportunities in expanding areas such as biofuels and biopharming.

  11. Radiation induced early maturing mutants in barley

    International Nuclear Information System (INIS)

    Kumar, R.; Chauhan, S.V.S.; Sharma, R.P.

    1978-01-01

    In M 2 generation, two early maturing plants were screened from a single spike progeny of a plant obtained from 20 kR of gamma-ray irradiation of a six-rowed barley (Hordeum vulgare L. var. Jyoti). Their true breeding nature was confirmed in M 3 generation. These mutants flower and mature 38 and 22 days earlier than those of control. (auth.)

  12. Search for endophytic diazotrophs in barley seeds

    Directory of Open Access Journals (Sweden)

    Myriam S. Zawoznik

    2014-06-01

    Full Text Available Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no antibiosis effects against Azospirillum brasilense Az39, a recognized PGPR.

  13. Localisation of genes for resistance against ¤Blumeria graminis¤ f.sp. ¤hordei¤ and ¤Puccinia graminis¤ in a cross between a barley cultivar and a wild barley (¤Hordeum vulgare¤ ssp. ¤spontaneum¤) line

    DEFF Research Database (Denmark)

    Backes, G.; Madsen, L.H.; Jaiser, H.

    2003-01-01

    The aims of this investigation have been to map new (quantitative) resistance genes against powdery mildew, caused by Blumeria graminis f.sp. hordei L., and leaf rust, caused by Puccinia hordei L., in a cross between the barley (Hordeum vulgare ssp. vulgare) cultivar "Vada" and the wild barley...... (Hordeum vulgare ssp. spontaneum) line "1B-87" originating from Israel. The population consisted of 121 recombinant inbred lines. Resistance against leaf rust and powdery mildew was tested on detached leaves. The leaf rust isolate "I-80" and the powdery mildew isolate "Va-4", respectively, were used...

  14. Spectral entropy as a mean to quantify water stress history for natural vegetation and irrigated agriculture in a water-stressed tropical environment

    Science.gov (United States)

    Kim, Y.; Johnson, M. S.

    2017-12-01

    Spectral entropy (Hs) is an index which can be used to measure the structural complexity of time series data. When a time series is made up of one periodic function, the Hs value becomes smaller, while Hs becomes larger when a time series is composed of several periodic functions. We hypothesized that this characteristic of the Hs could be used to quantify the water stress history of vegetation. For the ideal condition for which sufficient water is supplied to an agricultural crop or natural vegetation, there should be a single distinct phenological cycle represented in a vegetation index time series (e.g., NDVI and EVI). However, time series data for a vegetation area that repeatedly experiences water stress may include several fluctuations that can be observed in addition to the predominant phenological cycle. This is because the process of experiencing water stress and recovering from it generates small fluctuations in phenological characteristics. Consequently, the value of Hs increases when vegetation experiences several water shortages. Therefore, the Hs could be used as an indicator for water stress history. To test this hypothesis, we analyzed Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data for a natural area in comparison to a nearby sugarcane area in seasonally-dry western Costa Rica. In this presentation we will illustrate the use of spectral entropy to evaluate the vegetative responses of natural vegetation (dry tropical forest) and sugarcane under three different irrigation techniques (center pivot irrigation, drip irrigation and flood irrigation). Through this comparative analysis, the utility of Hs as an indicator will be tested. Furthermore, crop response to the different irrigation methods will be discussed in terms of Hs, NDVI and yield.

  15. Radiosensitivity study of cultured barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Xu Gang; Zhao Kongnan; Chen Qiufang

    1991-07-01

    For studying the radioactivity, forty seven varieties of dormant barley seeds were irradiated with various doses (0 ∼ 400 Gy) of 137 Cs γ-rays. The results showed that the dose-effects relations of seedling growth inhibition could be fitted by an equation of F(D) = 1 - (1 - e -a 1 D ) N , and the dose-effects of cell-nucleus, the frequency of root tip cell with chromosome aberations and peroxidase isoenzyme band could be expressed by a linear regression equation Y = A + B · X. The radioactivity of naked barley was much higher than of covered barley. According to different radiosensitivities the varieties studied could be divided into five types i.e. extreme resistant, resistant, intermediate, sensitive, and extreme sensitive. The results also showed that there was close relationship between the DNA content of cell-nucleus, peroxidase isoenzyme zymogram and radioactivity. The radiosensitivty was proportional to the DNA content. The volume of cell-nucleus varied inversly as D 50 of nucleus volume and no obvious correlation with the D 50 of seedling growth inhibition

  16. Characterization of a Thermo-Inducible Chlorophyll-Deficient Mutant in Barley

    Directory of Open Access Journals (Sweden)

    Rong Wang

    2017-11-01

    Full Text Available Leaf color is an important trait for not only controlling crop yield but also monitoring plant status under temperature stress. In this study, a thermo-inducible chlorophyll-deficient mutant, named V-V-Y, was identified from a gamma-radiated population of the barley variety Vlamingh. The leaves of the mutant were green under normal growing temperature but turned yellowish under high temperature in the glasshouse experiment. The ratio of chlorophyll a and chlorophyll b in the mutant declined much faster in the first 7–9 days under heat treatment. The leaves of V-V-Y turned yellowish but took longer to senesce under heat stress in the field experiment. Genetic analysis indicated that a single nuclear gene controlled the mutant trait. The mutant gene (vvy was mapped to the long arm of chromosome 4H between SNP markers 1_0269 and 1_1531 with a genetic distance of 2.2 cM and a physical interval of 9.85 Mb. A QTL for grain yield was mapped to the same interval and explained 10.4% of the yield variation with a LOD score of 4. This QTL is coincident with the vvy gene interval that is responsible for the thermo-inducible chlorophyll-deficient trait. Fine mapping, based on the barley reference genome sequence, further narrowed the vvy gene to a physical interval of 0.428 Mb with 11 annotated genes. This is the first report of fine mapping a thermo-inducible chlorophyll-deficient gene in barley.

  17. Understanding Water-Stress Responses in Soybean Using Hydroponics System-A Systems Biology Perspective.

    Science.gov (United States)

    Tripathi, Prateek; Rabara, Roel C; Shulaev, Vladimir; Shen, Qingxi J; Rushton, Paul J

    2015-01-01

    The deleterious changes in environmental conditions such as water stress bring physiological and biochemical changes in plants, which results in crop loss. Thus, combating water stress is important for crop improvement to manage the needs of growing population. Utilization of hydroponics system in growing plants is questionable to some researchers, as it does not represent an actual field condition. However, trying to address a complex problem like water stress we have to utilize a simpler growing condition like the hydroponics system wherein every input given to the plants can be controlled. With the advent of high-throughput technologies, it is still challenging to address all levels of the genetic machinery whether a gene, protein, metabolite, and promoter. Thus, using a system of reduced complexity like hydroponics can certainly direct us toward the right candidates, if not completely help us to resolve the issue.

  18. Understanding Water-Stress Responses in Soybean Using Hydroponics System—A Systems Biology Perspective

    Science.gov (United States)

    Tripathi, Prateek; Rabara, Roel C.; Shulaev, Vladimir; Shen, Qingxi J.; Rushton, Paul J.

    2015-01-01

    The deleterious changes in environmental conditions such as water stress bring physiological and biochemical changes in plants, which results in crop loss. Thus, combating water stress is important for crop improvement to manage the needs of growing population. Utilization of hydroponics system in growing plants is questionable to some researchers, as it does not represent an actual field condition. However, trying to address a complex problem like water stress we have to utilize a simpler growing condition like the hydroponics system wherein every input given to the plants can be controlled. With the advent of high-throughput technologies, it is still challenging to address all levels of the genetic machinery whether a gene, protein, metabolite, and promoter. Thus, using a system of reduced complexity like hydroponics can certainly direct us toward the right candidates, if not completely help us to resolve the issue. PMID:26734044

  19. Survival, physical and physiological changes of Taenia hydatigena eggs under different conditions of water stress.

    Science.gov (United States)

    Sánchez Thevenet, Paula; Alvarez, Hector Manuel; Basualdo, Juan Angel

    2017-06-01

    Taenia hydatigena eggs were investigated for morphological and physiological changes under water stress conditions. Fresh eggs were exposed at 31%, 47% and 89% of relative humidity (RH), and survival, size and ultrastructural changes were accounted up to 365 days of exposition. The article shows how each RH environment affects the vitality of the eggs. Results of this study suggest that T. hydatigena eggs have mechanisms to withstand water stress, indicating that the eggs clustering improves protection against desiccation, and that endogenous metabolism using triacylglycerols play an important role in the maintenance of embryo vitality under low, medium and high relative humidity conditions. This contributes to understanding the water stress resistance mechanism in eggs belonging to Taeniidae family. The findings shown herein have provided a basis to better comprehend basic biology and epidemiology of the cysticercosis caused by T. hydatigena. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Barley yellow dwarf virus in barley crops in Tunisia: prevalence and molecular characterization

    OpenAIRE

    Asma NAJAR; Imen HAMDI; Arvind VARSANI

    2017-01-01

    A field survey was conducted in Tunisia in the North-Eastern regions (Bizerte, CapBon and Zaghouan), the North-Western region (Kef) and the Central-Eastern region (Kairouan) during the 2011/2012 growing season, in order to determine the incidence and the geographic distribution of Barley yellow dwarf virus (BYDVs) in barley fields. Tissue blot immunoassays (TBIA) showed that BYDV was most common in Zaghouan (incidence 14%), Cap Bon (14%) and Bizerte (35%), in randomly collected samples from t...

  1. Effectiveness of rabbit manure biofertilizer in barley crop yield.

    Science.gov (United States)

    Islas-Valdez, Samira; Lucho-Constantino, Carlos A; Beltrán-Hernández, Rosa I; Gómez-Mercado, René; Vázquez-Rodríguez, Gabriela A; Herrera, Juan M; Jiménez-González, Angélica

    2017-11-01

    The quality of biofertilizers is usually assessed only in terms of the amount of nutrients that they supply to the crops and their lack of viable pathogens and phytotoxicity. The goal of this study was to determine the effectiveness of a liquid biofertilizer obtained from rabbit manure in terms of presence of pathogens, phytotoxicity, and its effect on the grain yield and other agronomic traits of barley (Hordeum vulgare L.). Environmental effects of the biofertilizer were also evaluated by following its influence on selected soil parameters. We applied the biofertilizer at five combinations of doses and timings each and in two application modes (foliar or direct soil application) within a randomized complete block design with three replicates and using a chemical fertilizer as control. The agronomic traits evaluated were plant height, root length, dry weight, and number of leaves and stems at three growth stages: tillering, jointing, and flowering. The effectiveness of the biofertilizer was significantly modified by the mode of application, the growth stage of the crop, and the dose of biofertilizer applied. The results showed that the foliar application of the biofertilizer at the tillering stage produced the highest increase in grain yield (59.7 %, p biofertilizer caused significant changes in soil, particularly concerning pH, EC, Ca, Zn, Mg, and Mn. It is our view that the production and use of biofertilizers are a reliable alternative to deal with a solid waste problem while food security is increased.

  2. Latent manganese deficiency increases transpiration in barley (Hordeum vulgare).

    Science.gov (United States)

    Hebbern, Christopher A; Laursen, Kristian Holst; Ladegaard, Anne H; Schmidt, Sidsel B; Pedas, Pai; Bruhn, Dan; Schjoerring, Jan K; Wulfsohn, Dvoralai; Husted, Søren

    2009-03-01

    To investigate if latent manganese (Mn) deficiency leads to increased transpiration, barley plants were grown for 10 weeks in hydroponics with daily additions of Mn in the low nM range. The Mn-starved plants did not exhibit visual leaf symptoms of Mn deficiency, but Chl a fluorescence measurements revealed that the quantum yield efficiency of PSII (F(v)/F(m)) was reduced from 0.83 in Mn-sufficient control plants to below 0.5 in Mn-starved plants. Leaf Mn concentrations declined from 30 to 7 microg Mn g(-1) dry weight in control and Mn-starved plants, respectively. Mn-starved plants had up to four-fold higher transpiration than control plants. Stomatal closure and opening upon light/dark transitions took place at the same rate in both Mn treatments, but the nocturnal leaf conductance for water vapour was still twice as high in Mn-starved plants compared with the control. The observed increase in transpiration was substantiated by (13)C-isotope discrimination analysis and gravimetric measurement of the water consumption, showing significantly lower water use efficiency in Mn-starved plants. The extractable wax content of leaves of Mn-starved plants was approximately 40% lower than that in control plants, and it is concluded that the increased leaf conductance and higher transpirational water loss are correlated with a reduction in the epicuticular wax layer under Mn deficiency.

  3. Residual transpiration as a component of salinity stress tolerance mechanism: a case study for barley.

    Science.gov (United States)

    Hasanuzzaman, Md; Davies, Noel W; Shabala, Lana; Zhou, Meixue; Brodribb, Tim J; Shabala, Sergey

    2017-06-19

    While most water loss from leaf surfaces occurs via stomata, part of this loss also occurs through the leaf cuticle, even when the stomata are fully closed. This component, termed residual transpiration, dominates during the night and also becomes critical under stress conditions such as drought or salinity. Reducing residual transpiration might therefore be a potentially useful mechanism for improving plant performance when water availability is reduced (e.g. under saline or drought stress conditions). One way of reducing residual transpiration may be via increased accumulation of waxes on the surface of leaf. Residual transpiration and wax constituents may vary with leaf age and position as well as between genotypes. This study used barley genotypes contrasting in salinity stress tolerance to evaluate the contribution of residual transpiration to the overall salt tolerance, and also investigated what role cuticular waxes play in this process. Leaves of three different positions (old, intermediate and young) were used. Our results show that residual transpiration was higher in old leaves than the young flag leaves, correlated negatively with the osmolality, and was positively associated with the osmotic and leaf water potentials. Salt tolerant varieties transpired more water than the sensitive variety under normal growth conditions. Cuticular waxes on barley leaves were dominated by primary alcohols (84.7-86.9%) and also included aldehydes (8.90-10.1%), n-alkanes (1.31-1.77%), benzoate esters (0.44-0.52%), phytol related compounds (0.22-0.53%), fatty acid methyl esters (0.14-0.33%), β-diketones (0.07-0.23%) and alkylresorcinols (1.65-3.58%). A significant negative correlation was found between residual transpiration and total wax content, and residual transpiration correlated significantly with the amount of primary alcohols. Both leaf osmolality and the amount of total cuticular wax are involved in controlling cuticular water loss from barley leaves under well

  4. Study of sugar phloem unloading in ripening grape berries under water stress conditions

    Directory of Open Access Journals (Sweden)

    Zenphing Wang

    2003-12-01

    Full Text Available Sugar phloem unloading in ripening grape berries (Vitis vinifera L. cv. Syrah was studied under water stress conditions using the «beny-cup» technique. After veraison, berry growth, the potential Exposed Leaf Area (pELA and photosynthetic activity are clearly reduced in water-stressed vines (- 0.5 > Ψb > - 0.6 MPa as compared to normal 1 Ψ-watcred vines (Mb = - 0.2 MPa. The ratio pELA/yield is also reduced, which is particular to this experiment. The beiries' ripening period (between veraison and maturity can be divided into three growth phases, Illa, Illb and IIlc. During phase Ma, the berries grow rapidly; at this point, water stress severely inhibits cell expan¬ sion of the berries but does not impact on daily sugar accumulation. During phase Mb, the berries grow slowly in both water-stressed and control vines. Water stress can shorten this phase and reduce sugar accumulation in the berries by decreasing daily sugar unloading. During phase II le, the Iresh weight and volume of the berries decreases as does the daily sugar unloading. During the day, sugar unloading in ripening berries occurs mainly in the morning (7 am to 10.30 am and at noon (1 to 1.30 pm; little sugar is unloaded in the afternoon (4 pm to 4.30 pin. Moderate water stress from veraison to maturity affects végétative growth (i.e. the growth of primary and secoridary shoots, and reduces the exposed leaf area, photosynthetic activity, berry growth, and the accumulation of sugar at the end of ripening (phases Mb and IIlc.

  5. Seed size effects on the response of seedlings of Acacia asak (Forssk.) Willd to water stress

    International Nuclear Information System (INIS)

    El Atta, H.A.; Areef, I.M.; Ahmed, A.I.

    2016-01-01

    Dry tropical forests are characterized by unpredictable spells of drought and climate change. Saudi Arabia mostly falls within the arid zone and some few scattered areas fall in the semiarid zone mainly in the South Western region. Rainfall is sparse and with sporadic distribution. Drought is the most critical factor for restoration of the tree cover. Within a tree, seeds vary in size from large to small seeds. Although several researchers have studied the effect of within species variation in seed size on seedlings growth parameters, however there is a lack of knowledge regarding the effect of seed size on stress tolerance (Khurana and Singh 2000). We assumed that seedlings grown from different seed sizes from the same tree species may influence their response to water stress. Seeds of Acacia asak (Forssk.) Willd. were categorized into large, medium and small seeds on the basis of the seed weight. Seedlings from the three seed sizes were grown in potted soil and subjected to 5 levels of field water capacity (FC) (100, 75, 50, 25 and 15 percent) in the greenhouse. The Objective was to evaluate the response of seedling grown (from different seed sizes) to water stress and to understand the acclimation of seedlings to water stress. Water stress significantly reduced RWC, leaf area, and shoot length, fresh and dry weight. Significant correlations between growth parameters and water stress level were recorded. Seedlings from large seeds were heavier and comparatively less affected by drought compared to seedlings from smaller seeds. In all seedlings root length increased significantly and more biomass was allocated to roots than to shoots. However, at severe water stress (15 percent FC) no significant differences were reported between the three seedling categories. Therefore, raising of seedlings from large seeds is more appropriate for tree restoration programs under drought conditions. (author)

  6. Water Stress in Global Transboundary River Basins: Significance of Upstream Water Use on Downstream Stress

    Science.gov (United States)

    Munia, H.; Guillaume, J. H. A.; Mirumachi, N.; Porkka,M.; Wada, Yoshihide; Kummu, M.

    2016-01-01

    Growing population and water demand have increased pressure on water resources in various parts of the globe, including many transboundary river basins. While the impacts of upstream water use on downstream water availability have been analyzed in many of these international river basins, this has not been systematically done at the global scale using coherent and comparable datasets. In this study, we aim to assess the change in downstream water stress due to upstream water use in the world's transboundary river basins. Water stress was first calculated considering only local water use of each sub-basin based on country-basin mesh, then compared with the situation when upstream water use was subtracted from downstream water availability. Wefound that water stress was generally already high when considering only local water use, affecting 0.95-1.44 billion people or 33%-51% of the population in transboundary river basins. After accounting for upstream water use, stress level increased by at least 1 percentage-point for 30-65 sub-basins, affecting 0.29-1.13 billion people. Altogether 288 out of 298 middle-stream and downstream sub-basin areas experienced some change in stress level. Further, we assessed whether there is a link between increased water stress due to upstream water use and the number of conflictive and cooperative events in the transboundary river basins, as captured by two prominent databases. No direct relationship was found. This supports the argument that conflicts and cooperation events originate from a combination of different drivers, among which upstream-induced water stress may play a role. Our findings contribute to better understanding of upstream-downstream dynamics in water stress to help address water allocation problems.

  7. Hyperspectral detection of a subsurface CO2 leak in the presence of water stressed vegetation.

    Directory of Open Access Journals (Sweden)

    Gabriel J Bellante

    Full Text Available Remote sensing of vegetation stress has been posed as a possible large area monitoring tool for surface CO2 leakage from geologic carbon sequestration (GCS sites since vegetation is adversely affected by elevated CO2 levels in soil. However, the extent to which remote sensing could be used for CO2 leak detection depends on the spectral separability of the plant stress signal caused by various factors, including elevated soil CO2 and water stress. This distinction is crucial to determining the seasonality and appropriateness of remote GCS site monitoring. A greenhouse experiment tested the degree to which plants stressed by elevated soil CO2 could be distinguished from plants that were water stressed. A randomized block design assigned Alfalfa plants (Medicago sativa to one of four possible treatment groups: 1 a CO2 injection group; 2 a water stress group; 3 an interaction group that was subjected to both water stress and CO2 injection; or 4 a group that received adequate water and no CO2 injection. Single date classification trees were developed to identify individual spectral bands that were significant in distinguishing between CO2 and water stress agents, in addition to a random forest classifier that was used to further understand and validate predictive accuracies. Overall peak classification accuracy was 90% (Kappa of 0.87 for the classification tree analysis and 83% (Kappa of 0.77 for the random forest classifier, demonstrating that vegetation stressed from an underground CO2 leak could be accurately discerned from healthy vegetation and areas of co-occurring water stressed vegetation at certain times. Plants appear to hit a stress threshold, however, that would render detection of a CO2 leak unlikely during severe drought conditions. Our findings suggest that early detection of a CO2 leak with an aerial or ground-based hyperspectral imaging system is possible and could be an important GCS monitoring tool.

  8. Hyperspectral detection of a subsurface CO2 leak in the presence of water stressed vegetation.

    Science.gov (United States)

    Bellante, Gabriel J; Powell, Scott L; Lawrence, Rick L; Repasky, Kevin S; Dougher, Tracy

    2014-01-01

    Remote sensing of vegetation stress has been posed as a possible large area monitoring tool for surface CO2 leakage from geologic carbon sequestration (GCS) sites since vegetation is adversely affected by elevated CO2 levels in soil. However, the extent to which remote sensing could be used for CO2 leak detection depends on the spectral separability of the plant stress signal caused by various factors, including elevated soil CO2 and water stress. This distinction is crucial to determining the seasonality and appropriateness of remote GCS site monitoring. A greenhouse experiment tested the degree to which plants stressed by elevated soil CO2 could be distinguished from plants that were water stressed. A randomized block design assigned Alfalfa plants (Medicago sativa) to one of four possible treatment groups: 1) a CO2 injection group; 2) a water stress group; 3) an interaction group that was subjected to both water stress and CO2 injection; or 4) a group that received adequate water and no CO2 injection. Single date classification trees were developed to identify individual spectral bands that were significant in distinguishing between CO2 and water stress agents, in addition to a random forest classifier that was used to further understand and validate predictive accuracies. Overall peak classification accuracy was 90% (Kappa of 0.87) for the classification tree analysis and 83% (Kappa of 0.77) for the random forest classifier, demonstrating that vegetation stressed from an underground CO2 leak could be accurately discerned from healthy vegetation and areas of co-occurring water stressed vegetation at certain times. Plants appear to hit a stress threshold, however, that would render detection of a CO2 leak unlikely during severe drought conditions. Our findings suggest that early detection of a CO2 leak with an aerial or ground-based hyperspectral imaging system is possible and could be an important GCS monitoring tool.

  9. Plant Water Stress Affects Interactions Between an Invasive and a Naturalized Aphid Species on Cereal Crops.

    Science.gov (United States)

    Foote, N E; Davis, T S; Crowder, D W; Bosque-Pérez, N A; Eigenbrode, S D

    2017-06-01

    In cereal cropping systems of the Pacific Northwestern United States (PNW), climate change is projected to increase the frequency of drought during summer months, which could increase water stress for crop plants. Yet, it remains uncertain how interactions between herbivore species are affected by drought stress. Here, interactions between two cereal aphids present in PNW cereal systems, Metopolophium festucae (Theobald) subsp. cerealium (a newly invasive species) and Rhopalosiphum padi L. (a naturalized species), were tested relative to wheat water stress. When aphids were confined in leaf cages on wheat, asymmetrical facilitation occurred; per capita fecundity of R. padi was increased by 46% when M. festucae cerealium was also present, compared to when only R. padi was present. Imposed water stress did not influence this interaction. When aphids were confined on whole wheat plants, asymmetrical competition occurred; cocolonization inhibited M. festucae cerealium population growth but did not affect R. padi population growth. Under conditions of plant water stress, however, the inhibitory effect of R. padi on M. festucae cerealium was not observed. We conclude that beneficial effects of cocolonization on R. padi are due to a localized plant response to M. festucae cerealium feeding, and that cocolonization of plants is likely to suppress M. festucae cerealium populations under ample water conditions, but not when plants are water stressed. This suggests that plant responses to water stress alter the outcome of competition between herbivore species, with implications for the structure of pest communities on wheat during periods of drought. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  10. Effects of water stress on photosynthetic electron transport, photophosphorylation, and metabolite levels of Xanthium strumarium mesophyll cells.

    Science.gov (United States)

    Sharkey, T D; Badger, M R

    1982-12-01

    Several component processes of photosynthesis were measured in osmotically stressed mesophyll cells of Xanthium strumarium L. The ribulose-1,5-bisphosphate regeneration capacity was reduced by water stress. Photophoshorylation was sensitive to water stress but photosynthetic electron transport was unaffected by water potentials down to-40 bar (-4 MPa). The concentrations of several intermediates of the photosynthetic carbon-reduction cycle remained relatively constant and did not indicate that ATP supply was limiting photosynthesis in the water-stressed cells.

  11. The barley anion channel, HvALMT1, has multiple roles in guard cell physiology and grain metabolism.

    Science.gov (United States)

    Xu, Muyun; Gruber, Benjamin D; Delhaize, Emmanuel; White, Rosemary G; James, Richard A; You, Jiangfeng; Yang, Zhenming; Ryan, Peter R

    2015-01-01

    The barley (Hordeum vulgare) gene HvALMT1 encodes an anion channel in guard cells and in certain root tissues indicating that it may perform multiple roles. The protein localizes to the plasma membrane and facilitates malate efflux from cells when constitutively expressed in barley plants and Xenopus oocytes. This study investigated the function of HvALMT1 further by identifying its tissue-specific expression and by generating and characterizing RNAi lines with reduced HvALMT1 expression. We show that transgenic plants with 18-30% of wild-type HvALMT1 expression had impaired guard cell function. They maintained higher stomatal conductance in low light intensity and lost water more rapidly from excised leaves than the null segregant control plants. Tissue-specific expression of HvALMT1 was investigated in developing grain and during germination using transgenic barley lines expressing the green fluorescent protein (GFP) with the HvALMT1 promoter. We found that HvALMT1 is expressed in the nucellar projection, the aleurone layer and the scutellum of developing barley grain. Malate release measured from isolated aleurone layers prepared from imbibed grain was significantly lower in the RNAi barley plants compared with control plants. These data provide molecular and physiological evidence that HvALMT1 functions in guard cells, in grain development and during germination. We propose that HvALMT1 releases malate and perhaps other anions from guard cells to promote stomatal closure. The likely roles of HvALMT1 during seed development and grain germination are also discussed. © 2014 Scandinavian Plant Physiology Society.

  12. Systemic responses of barley to the 3-hydroxy-decanoyl-homoserine lactone producing plant beneficial endophyte Acidovorax radicis N35

    Directory of Open Access Journals (Sweden)

    Shengcai Han

    2016-12-01

    Full Text Available Quorum sensing auto-inducers of the N-acyl homoserine lactone (AHL type produced by Gram-negative bacteria have different effects on plants including stimulation on root growth and/or priming or acquirement of systemic resistance in plants. In this communication the influence of AHL production of the plant growth promoting endophytic rhizosphere bacterium Acidovorax radicis N35 on barley seedlings was investigated. A. radicis N35 produces 3-hydroxy-C10-homoserine lactone (3-OH-C10-HSL as the major AHL compound. To study the influence of this QS autoinducer on the interaction with barley, the araI-biosynthesis gene was deleted. The comparison of inoculation effects of the A. radicis N35 wild type and the araI mutant resulted in remarkable differences. While the N35 wild type colonized plant roots effectively in microcolonies, the araI mutant occurred at the root surface as single cells. Furthermore, in a mixed inoculum the wild type was much more prevalent in colonization than the araI mutant documenting that the araI mutation affected root colonization. Nevertheless, a significant plant growth promoting effect could be shown after inoculation of barley with the wild type and the araI mutant in soil after two months cultivation. While A. radicis N35 wild type showed only a very weak induction of early defense responses in plant RNA expression analysis, the araI mutant caused increased expression of flavonoid biosynthesis genes. This was corroborated by the accumulation of several flavonoid compounds such as saponarin and lutonarin in leaves of root inoculated barley seedlings. Thus, although the exact role of the flavonoids in this plant response is not clear yet, it can be concluded, that the synthesis of AHLs by A. radicis has implications on the perception by the host plant barley and thereby contributes to the establishment and function of the bacteria-plant interaction.

  13. Enhanced quantitative resistance against fungal disease by combinatorial expression of different barley antifungal proteins in transgenic tobacco

    DEFF Research Database (Denmark)

    Jach, G; Görnhardt, B; Mundy, J

    1995-01-01

    cDNAs encoding three proteins from barley (Hordeum vulgare), a class-II chitinase (CHI), a class-II beta-1,3-glucanase (GLU) and a Type-I ribosome-inactivating protein (RIP) were expressed in tobacco plants under the control of the CaMV 35S-promoter. High-level expression of the transferred genes...... was detected in the transgenic plants by Northern and Western blot analysis. The leader peptides in CHI and GLU led to accumulation of these proteins in the intercellular space of tobacco leaves. RIP, which is naturally deposited in the cytosol of barley endosperm cells, was expressed either in its original...... cytosolic form or fused to a plant secretion peptide (spRIP). Fungal infection assays revealed that expression of the individual genes in each case resulted in an increased protection against the soilborne fungal pathogen Rhizoctonia solani, which infects a range of plant species including tobacco...

  14. Lysine metabolism in antisense C-hordein barley grains

    DEFF Research Database (Denmark)

    Schmidt, Daiana; Rizzi, Vanessa; Gaziola, Salete A

    2015-01-01

    The grain proteins of barley are deficient in lysine and threonine due to their low concentrations in the major storage protein class, the hordeins, especially in the C-hordein subgroup. Previously produced antisense C-hordein transgenic barley lines have an improved amino acid composition, with ...

  15. Revisit to Ethiopian traditional barley-based food

    Directory of Open Access Journals (Sweden)

    Jemal Mohammed

    2016-06-01

    Full Text Available Barley is the number one food crop in the highland parts of North Eastern Ethiopia produced by subsistence farmers grown as landraces. Barley producers in Ethiopia have given it the name gebs ye ehil nigus, which means barley is the king of crops, due to its suitability for preparing many of the known Ethiopians traditional dishes. Various barley foods and drinks play an important role in the socioeconomic and cultural life of Ethiopians, but detailed descriptions related to their preparation and their socioeconomic and cultural roles are not well-recorded and documented like most of the Ethiopian cultural foods. Foods such as ingera, kita, dabo, kolo, genfo, beso, chuko, shamet, tihlo, kinch, and shorba are the most commonly known traditional Ethiopian barley-based foods. These products are prepared from either roasted whole grain, raw and roasted-milled grain, or cracked grain as main, side, ceremonial, and recuperating dishes. The various barley-based traditional foods have perceived qualities and health benefits by the consumers. For example, genfo is served to breast-feeding mothers with the belief that it enhances breast milk production and serves as a good substitute for breast milk. Beso is claimed to be a remedy for gastritis, while genfo and kinche are used to heal broken bones and fractures. Considering the Western consumers' trend on functional foods and health benefits of barley, Ethiopian traditional barley-based foods are worth studying as functional foods, which can be appealing to Western consumers.

  16. Molecular characterization of barley ( Hordeum vulgare L.) genome ...

    African Journals Online (AJOL)

    The present work aimed to select drought tolerant barley (Hordeum vulgare L.) cultivars through identification of stress genes responsible for drought tolerance. Several barley genotypes were tested for drought resistance using specific molecular markers, nine out of all the genotypes were chosen for this study; five out of ...

  17. Combining unmalted barley and pearling gives good quality brewing

    NARCIS (Netherlands)

    Donkelaar, van Laura H.G.; Hageman, Jos A.; Oguz, Serhat; Noordman, Tom R.; Boom, Remko M.; Goot, van der Atze Jan

    2016-01-01

    Brewing with unmalted barley can reduce the use of raw materials, thereby increasing the efficiency of the brewing process. However, unmalted barley contains several undesired components for brewing and has a low enzymatic activity. Pearling, an abrasive milling method, has been proposed as a

  18. (GPx) activity in young barley seedlings enriched with selenium

    African Journals Online (AJOL)

    AJB_YOMI

    2011-09-21

    Sep 21, 2011 ... E-mail: guzx@njau.edu.cn. Tel/Fax: +86. 25 84396293. have been used for animal feeds and beer malts. Recently, young barley seedlings have been used as food material for people in Asian countries such as China,. Japan, and Korea. Young barley seedlings are rich in dietary fiber, chlorophyll, carotene ...

  19. stability analysis of food barley genotypes in northern ethiopia

    African Journals Online (AJOL)

    ACSS

    interaction and stability for barley grain yield and yield related traits in the growing ... that the environments were diverse; causing most of the variation in grain yield. ... component axes IPCA1, IPCA2 and IPCA3, which explained 58.06, 27.11 and ..... AMMI analysis of variance for grain yield (t ha-1) of food barley genotypes ...

  20. 7 CFR 801.3 - Tolerances for barley pearlers.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Tolerances for barley pearlers. 801.3 Section 801.3 Agriculture Regulations of the Department of Agriculture (Continued) GRAIN INSPECTION, PACKERS AND STOCKYARD... FOR GRAIN INSPECTION EQUIPMENT § 801.3 Tolerances for barley pearlers. The maintenance tolerances for...

  1. A multimodal image sensor system for identifying water stress in grapevines

    Science.gov (United States)

    Zhao, Yong; Zhang, Qin; Li, Minzan; Shao, Yongni; Zhou, Jianfeng; Sun, Hong

    2012-11-01

    Water stress is one of the most common limitations of fruit growth. Water is the most limiting resource for crop growth. In grapevines, as well as in other fruit crops, fruit quality benefits from a certain level of water deficit which facilitates to balance vegetative and reproductive growth and the flow of carbohydrates to reproductive structures. A multi-modal sensor system was designed to measure the reflectance signature of grape plant surfaces and identify different water stress levels in this paper. The multi-modal sensor system was equipped with one 3CCD camera (three channels in R, G, and IR). The multi-modal sensor can capture and analyze grape canopy from its reflectance features, and identify the different water stress levels. This research aims at solving the aforementioned problems. The core technology of this multi-modal sensor system could further be used as a decision support system that combines multi-modal sensory data to improve plant stress detection and identify the causes of stress. The images were taken by multi-modal sensor which could output images in spectral bands of near-infrared, green and red channel. Based on the analysis of the acquired images, color features based on color space and reflectance features based on image process method were calculated. The results showed that these parameters had the potential as water stress indicators. More experiments and analysis are needed to validate the conclusion.

  2. Evaluation of 10 wheat cultivars under water stress at Moghan (Iran ...

    African Journals Online (AJOL)

    Hami

    2011-09-14

    Sep 14, 2011 ... Accepted 20 May, 2011. Water deficit is one of the main abiotic factors that affect yield and yield component of wheat planted in ... evaluate the effects of water stress on seed yield and yield components of ten wheat cultivars and lines that differ in .... Analysis of variance is presented in Table 2. According to.

  3. Leaf water stress detection utilizing thematic mapper bands 3, 4 and 5 in soybean plants

    Science.gov (United States)

    Holben, B. N.; Schutt, J. B.; Mcmurtrey, J., III

    1983-01-01

    The total and diffuse radiance responses of Thematic Mapper bands 3 (0.63-0.69 microns), 4 (0.76-0.90 microns), and 5 (1.55-1.75 microns) to water stress in a soybean canopy are compared. Polarization measurements were used to separate the total from the diffuse reflectance; the reflectances were compared statistically at a variety of look angles at 15 min intervals from about 09.00 until 14.00 hrs EST. The results suggest that remotely sensed data collected in the photographic infrared region (TM4) are sensitive to leaf water stress in a 100 percent canopy cover of soybeans, and that TM3 is less sensitive than TM4 for detection of reversible foliar water stress. The mean values of TM5 reflectance data show similar trends to TM4. The primary implication of this study is that remote sensing of water stress in green plant canopies is possible in TM4 from ground-based observations primarily through the indirect link of leaf geometry.

  4. Infrared thermometry of water-stressed crops - emerging methods and technologies

    Science.gov (United States)

    Infrared thermometry has shown potential to quantify water stress in crop canopy. This presentation will outline the limited irrigation experiments by the USDA-ARS in northern Colorado, which is used for a framework to evaluate canopy temperature. Recent methods have been introduced that may be accu...

  5. Estimating maize water stress by standard deviation of canopy temperature in thermal imagery

    Science.gov (United States)

    A new crop water stress index using standard deviation of canopy temperature as an input was developed to monitor crop water status. In this study, thermal imagery was taken from maize under various levels of deficit irrigation treatments in different crop growing stages. The Expectation-Maximizatio...

  6. Long-term application of the Crop Water Stress Index in Midwest agro-ecosystems

    Science.gov (United States)

    Agricultural land in the Midwestern US is largely used for rainfed corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) production. The native ecosystems in this region predominantly consist of tallgrass prairie. Water stress can occur in summer which can affect carbon assimilation of those agro-...

  7. Development of an irrigation scheduling software based on model predicted crop water stress

    Science.gov (United States)

    Modern irrigation scheduling methods are generally based on sensor-monitored soil moisture regimes rather than crop water stress which is difficult to measure in real-time, but can be computed using agricultural system models. In this study, an irrigation scheduling software based on RZWQM2 model pr...

  8. Leaf temperature of maize and crop water stress index with variable irrigation and nitrogen supply

    Science.gov (United States)

    Water scarcity due to changing climate, population growth, and economic development is a major threat to the sustainability of irrigated agriculture in the Western United States and other regions around the world. Water stress indices based on crop canopy temperature can be useful for assessing plan...

  9. Estimating anthropogenic ecological water stress in the US great lakes region

    Science.gov (United States)

    Anthropocentric water resources management that prioritizes socio-economic growth can cause harmful ecological water stress by depriving aquatic ecosystems of the water needed to sustain habitats. It is important to better understand the impacts of water withdrawal by different economic sectors (e.g...

  10. Moderate water stress affects tomato leaf water relations in dependence on the nitrogen supply

    NARCIS (Netherlands)

    Garcia, A.L.; Marcelis, L.F.M.; Garcia-Sanchez, F.; Nicolas, N.; Martinez, V.

    2007-01-01

    The responses of water relations, stomatal conductance (g(s)) and growth parameters of tomato (Lycopersicon esculentum Mill. cv. Royesta) plants to nitrogen fertilisation and drought were studied. The plants were subjected to a long-term, moderate and progressive water stress by adding 80 % of the

  11. Crop coefficient, yield response to water stress and water productivity of teff (Eragrostis tef (Zucc.)

    NARCIS (Netherlands)

    Araya, A.; Stroosnijder, L.; Girmay, G.; Keesstra, S.D.

    2011-01-01

    In the semi-arid region of Tigray, Northen Ethiopia a two season experiment was conducted to measure evapotranspiration, estimate yield response to water stress and derive the crop coefficient of teff using the single crop coefficient approach with simple, locally made lysimeters and field plots.

  12. Seasonal water stress and the resistance of Pinus yunnanensis to a bark-beetle-associated fungus.

    Science.gov (United States)

    Salle, Aurelien; Ye, Hui; Yart, Annie; Lieutier, François

    2008-05-01

    We examined the influence of seasonal water stress on the resistance of Pinus yunnanensis (Franch.) to inoculation with Leptographium yunnanense, a pathogenic fungus associated with the aggressive bark beetle, Tomicus n. sp. Experiments took place between October 1997 and November 1999 in two plots located at the top and at the foot of a hill in Shaogiu, China, a region characterized by dry winters and wet summers. Following isolated and mass fungal inoculations, we observed the reaction zone length, fungal growth in the phloem, and the occlusion, blue-staining and specific hydraulic conductivity of the sapwood. Measurements of soil and needle water contents and predawn needle water potentials confirmed that trees were subject to mild water stress during winter, especially at the drier hilltop site. Measures of tree resistance to fungal infection of phloem and sapwood were congruent and indicated that trees were most susceptible to inoculation during the wet summer, especially at the lower-elevation plot. Specific hydraulic conductivity decreased after inoculation in summer. The results indicate that mild seasonal water stress is not likely responsible for the recent extensive damage to young P. yunnanensis stands by Tomicus n. sp. in the vicinity of our study plots. Rather, the results suggest that mild water stress enhances tree resistance to fungal pathogens associated with Tomicus n. sp.

  13. Interactive effects of rice residue and water stress on growth and metabolism of wheat seedlings

    Directory of Open Access Journals (Sweden)

    Nimisha Amist

    2014-08-01

    Full Text Available In the present study effects of rice residue with and without water stress were studied on Triticum aestivum L. cv. Shatabadi. The mixture of residue and garden soil in 1:1 ratio was considered as 50% (R1 and only decomposed residue as 100% (R2. Garden soil was taken as control. Twenty five seeds were sown in each experimental trays filled with soil mixture according to the treatments. Trays were arranged in two groups. After 15 days one set was subjected to water stress (WS by withholding water supply for 3 days. Morphological and biochemical parameters of 18 days old seedlings were recorded. Seedling height decreased in all treatments. A gradual decrease in relative water content, pigment and protein contents of wheat seedlings were observed. Sugar and proline contents increased in treatments. An increase in malondialdehyde (MDA content and antioxidative enzyme activities was recorded. Elevation in catalase activity was observed in all treatments except in plants with water deficit. Ascorbate peroxidase (APX and guaiacol peroxidase (GPX activities increased when residue mixed with soil but decreased in seedlings under the combined influence of the residue and water stress. Higher amount of MDA and lower activities of APX and GPX reflected the oxidative damage in seedlings under combined treatments. Rice residue inhibited growth of wheat seedlings. Water stress intensified the effects of residue.

  14. Effects of Water Stress on Photosynthesis and Chlorophyll Fluorescence of the Sugar Beet

    Directory of Open Access Journals (Sweden)

    HAN Kai-hong

    2015-10-01

    Full Text Available To investigate the effect of water stress and rewatering on sugar beet yield and its corresponding photosynthetic parameters, and to provide the basis of water management for the sugar beet fields, pool experiments in an artificial proof canopy were set up to observe changes of beet net photosynthetic rate(Pn, transpiration rate(Tr, water use efficiency(WUE and stomatal limitation (Ls, intercellular CO2 oncentration(Ci, and PSⅡ maximum quantum yield(Fv/Fm. The results indicated that the diurnal variation of Tr and Pn in CK treatment (whole growth period replenishment at different times near "unimodal" type; and water shortage treatments presented "twin peaks" change. Diurnal transpiration capacity(DTC under water stress at sugar accumulation stage reduced by 70.16%~74.81% and diurnal photosynthetic capacity(DPC was 63.48%~69.96% lower than that of CK, while diurnal water use efficiency(WUEd increased by 19.28%~22.39%. Rehydration helped Tr and Pn recovery, but did not reach unstressed levels. Ls changes under extremely dry environment had a midday trough "twin peaks" feature, and Ci was at "double-dip" in consistent with the timing of Ls; Water stress inhibited and inactivated photochemical reaction center of midday PSⅡ. Water stress led to irreversible decrease in the Pn and Tr, and prolonged the Pn inefficient period, which become the important factor of influencing the sugar beet yield.

  15. Effect of water stress on yield and yield components of sunflower ...

    African Journals Online (AJOL)

    A field experiment during year 2009 was conducted in the research station of the University of Tehran, College of Abouraihan in Pakdasht region, Iran. The study was aimed to investigate the effect of water stress on seed yield, yield component and some quantitative traits of four sunflower hybrids namely Azargol, Alstar, ...

  16. Evaluation of 10 wheat cultivars under water stress at Moghan (Iran ...

    African Journals Online (AJOL)

    Water deficit is one of the main abiotic factors that affect yield and yield component of wheat planted in arid and semi-arid regions. This study was conducted to evaluate the effect of water stress on wheat yield and yield component during 2008 at Moghan conditions. The objective of this study was to evaluate the effects of ...

  17. Interactions between abscisic acid and cytokinins during water stress and subsequent rehydration

    Czech Academy of Sciences Publication Activity Database

    Pospíšilová, Jana; Vágner, Martin; Malbeck, Jiří; Trávníčková, Alena; Baťková, Petra

    2005-01-01

    Roč. 49, - (2005), s. 533-540 ISSN 0006-3134 R&D Projects: GA ČR GA522/02/1099; GA AV ČR(CZ) IAA638105 Institutional research plan: CEZ:AV0Z50380511 Keywords : abscisic acid * cytokinins * water stress Subject RIV: EF - Botanics Impact factor: 0.792, year: 2005

  18. Water Stress Assessment in Jharkhand State Using Soil Data and GIS

    African Journals Online (AJOL)

    In this paper an attempt has been made to study the interrelationship of water resources available with that of soil class and its properties including soil drainage and erosional characteristics which has been used to generate drainage stress map and water stress map inferring the basic reason for water scarcity in the district ...

  19. Liquid organomineral fertilizer containing humic substances on soybean grown under water stress

    Directory of Open Access Journals (Sweden)

    Marcelo R. V. Prado

    2016-05-01

    Full Text Available ABSTRACT This study evaluated the effect of an organomineral fertilizer enriched with humic substances on soybean grown under water stress. The experiment was performed in a greenhouse using a Red Latosol (Oxisol with adequate fertility as substrate, in which soybean plants were cultivated with and without water stress. The experimental design was randomized blocks, in a 2 x 5 factorial scheme (two moisture levels and five fertilizer doses: 0, 1, 2, 4 and 8 mL dm-3, totaling 10 treatments, with four replicates. The organomineral fertilizer was applied in the soil 21 days after plant emergence and the water regimes were established one week thereafter. The fertilizer was not able to attenuate the effects of water stress, reducing soybean grain yield by more than 50% compared with plants cultivated under no stress. Fertilizer doses caused positive response on soybean nutrition and grain yield and, under water stress condition, the most efficient dose was 5.4 mL dm-3. There were lower leaf concentrations of nitrogen, phosphorus and potassium and higher concentrations of sulfur in plants under stress. Humic substances favor the absorption of micronutrients.

  20. Water stress projections for the northeastern and Midwestern United States in 2060: anthropogenic and ecological consequences

    Science.gov (United States)

    Brian G. Tavernia; Mark D. Nelson; Peter Caldwell; Ge Sun

    2013-01-01

    Future climate and land-use changes and growing human populations may reduce the abundance of water resources relative to anthropogenic and ecological needs in the Northeast and Midwest (U.S.). We used output from WaSSI, a water accounting model, to assess potential changes between 2010 and 2060 in (1) anthropogenic water stress for watersheds throughout the Northeast...

  1. Effect of soil water stress on yield and proline content of four wheat ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... Four lines of bread wheat (N-82-9, N-83-5, ... Key words: Water stress, Triticum aestivum, yield, proline, TSS. .... Numbers in the columns followed by the same letters are not significantly different at P .... constituents, Acta Bot.

  2. Fermented Dough Characteristics of Wheat-barley-hemp Composites. Comparison of Two Dosages of Barley and Hemp Wholemeal/Flour

    Directory of Open Access Journals (Sweden)

    Marie Hrušková

    2016-01-01

    Full Text Available Wheat flour substitution by barley one led to shortening of fermentation and leavening times (about 14–57% and 35–83%, respectively as well as to lessening of dough volumes (about 25–75%, based on lowered protein quality (Zeleny value. Addition of barley flour affected specific bread volume; diminishing for wheat-barley blends 70:30 and 50:50 reached 30% and 43%, respectively. Volume of bread prepared from wheat-barley blend 70:30 enhanced by dehulled hemp wholemeal was the highest within the tested tri-composites set, achieving 130% of wheat-barley control; other hemp products caused the parameter decrease (from 8 to 33%. Within a group of bakery products containing 50% of barley flour, hulled hemp wholemeal partially supressed negative effect of barley flour – specific bread volumes increased about ca 15%. Commercial fine hemp flour samples demonstrated a reversal influence – its addition resulted into lower buns size than wheat-barley control (about 3–34%. Between wheat flour and both groups of flour tri-composites, PCA confirmed differences in dough and bread technological quality. Specific bread volume could be predicted according to maturograph dough elasticity, dough or bread OTG volumes.

  3. Rainfall and crop modeling-based water stress assessment for rainfed maize cultivation in peninsular India

    Science.gov (United States)

    Manivasagam, V. S.; Nagarajan, R.

    2018-04-01

    Water stress due to uneven rainfall distribution causes a significant impact on the agricultural production of monsoon-dependent peninsular India. In the present study, water stress assessment for rainfed maize crop is carried out for kharif (June-October) and rabi (October-February) cropping seasons which coincide with two major Indian monsoons. Rainfall analysis (1976-2010) shows that the kharif season receives sufficient weekly rainfall (28 ± 32 mm) during 26th-39th standard meteorological weeks (SMWs) from southwest monsoon, whereas the rabi season experiences a major portion of its weekly rainfall due to northeast monsoon between the 42nd and 51st SMW (31 ± 42 mm). The later weeks experience minimal rainfall (5.5 ± 15 mm) and thus expose the late sown maize crops to a severe water stress during its maturity stage. Wet and dry spell analyses reveal a substantial increase in the rainfall intensity over the last few decades. However, the distribution of rainfall shows a striking decrease in the number of wet spells, with prolonged dry spells in both seasons. Weekly rainfall classification shows that the flowering and maturity stages of kharif maize (33rd-39th SMWs) can suffer around 30-40% of the total water stress. In the case of rabi maize, the analysis reveals that a shift in the sowing time from the existing 42nd SMW (16-22 October) to the 40th SMW (1-7 October) can avoid terminal water stress. Further, AquaCrop modeling results show that one or two minimal irrigations during the flowering and maturity stages (33rd-39th SMWs) of kharif maize positively avoid the mild water stress exposure. Similarly, rabi maize requires an additional two or three lifesaving irrigations during its flowering and maturity stages (48th-53rd SMWs) to improve productivity. Effective crop planning with appropriate sowing time, short duration crop, and high yielding drought-resistant varieties will allow for better utilization of the monsoon rain, thus reducing water stress with

  4. Differential responses of two Egyptian barley (Hordeum vulgare L.) cultivars to salt stress.

    Science.gov (United States)

    Elsawy, Hayam I A; Mekawy, Ahmad Mohammad M; Elhity, Mahmoud A; Abdel-Dayem, Sherif M; Abdelaziz, Maha Nagy; Assaha, Dekoum V M; Ueda, Akihiro; Saneoka, Hirofumi

    2018-06-01

    Although barley (Hordeum vulgare L.) is considered a salt tolerant crop species, productivity of barley is affected differently by ionic, osmotic, and oxidative stresses resulting from a salty rhizosphere. The current study was conducted to elucidate the mechanism of salt tolerance in two barley cultivars, Giza128 and Giza126. The two cultivars were exposed to 200 mM NaCl hydroponically for 12 days. Although both cultivars accumulated a large amount of Na + in their leaves with similar concentrations, the growth of Giza128 was much better than that of Giza126, as measured by maintaining a higher dry weight, relative growth rate, leaf area, and plant height. To ascertain the underlying mechanisms of this differential tolerance, first, the relative expression patterns of the genes encoding Na + /H + antiporters (NHX) and the associated proton pumps (V-PPase and V-ATPase) as well as the gene encoding the plasma membrane PM H + -ATPase were analyzed in leaf tissues. Salt stress induced higher HvNHX1 expression in Giza128 (3.3-fold) than in Giza126 (1.9-fold), whereas the expression of the other two genes, HvNHX2 and HvNHX3, showed no induction in either cultivar. The expression of HvHVP1 and HvHVA was higher in Giza128 (3.8- and 2.1-fold, respectively) than in Giza126 (1.6- and 1.1-fold, respectively). The expression of the PM H + -ATPase (ha1) gene was induced more in Giza128 (8.8-fold) than in Giza126 (1.8-fold). Second, the capacity for ROS detoxification was assessed using the oxidative stress biomarkers electrolyte leakage ratio (ELR) and the concentrations of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ), and these parameters sharply increased in Giza126 leaves by 66.5%, 42.8% and 50.0%, respectively, compared with those in Giza128 leaves. The antioxidant enzyme (CAT, APX, sPOD, GR, and SOD) activities were significantly elevated by salt treatment in Giza128 leaves, whereas in Giza126, these activities were not significantly altered. Overall, the

  5. Genomic Prediction of Barley Hybrid Performance

    Directory of Open Access Journals (Sweden)

    Norman Philipp

    2016-07-01

    Full Text Available Hybrid breeding in barley ( L. offers great opportunities to accelerate the rate of genetic improvement and to boost yield stability. A crucial requirement consists of the efficient selection of superior hybrid combinations. We used comprehensive phenotypic and genomic data from a commercial breeding program with the goal of examining the potential to predict the hybrid performances. The phenotypic data were comprised of replicated grain yield trials for 385 two-way and 408 three-way hybrids evaluated in up to 47 environments. The parental lines were genotyped using a 3k single nucleotide polymorphism (SNP array based on an Illumina Infinium assay. We implemented ridge regression best linear unbiased prediction modeling for additive and dominance effects and evaluated the prediction ability using five-fold cross validations. The prediction ability of hybrid performances based on general combining ability (GCA effects was moderate, amounting to 0.56 and 0.48 for two- and three-way hybrids, respectively. The potential of GCA-based hybrid prediction requires that both parental components have been evaluated in a hybrid background. This is not necessary for genomic prediction for which we also observed moderate cross-validated prediction abilities of 0.51 and 0.58 for two- and three-way hybrids, respectively. This exemplifies the potential of genomic prediction in hybrid barley. Interestingly, prediction ability using the two-way hybrids as training population and the three-way hybrids as test population or vice versa was low, presumably, because of the different genetic makeup of the parental source populations. Consequently, further research is needed to optimize genomic prediction approaches combining different source populations in barley.

  6. Ozone and Water Stress: Effects on the Behaviour of Two White Clover Biotypes

    Directory of Open Access Journals (Sweden)

    Massimo Fagnano

    Full Text Available ozone pollution, water stress, stomata conductance, ozone uptake, clover, OTC.Ozone is a strong oxidizing pollutant which derives by alteration of the photolytic NOx cycle and it accumulates in the troposphere spreading in rural areas and therefore determining injuries on natural vegetation and crops. Since its penetration occurs mainly through stomata, all factors which alter plant-atmosphere relations could be able to modify plant response to ozone. Interaction between ozone and water stress in Mediterranean environment was studied on ozone resistant and sensitive biotypes of white clover, which were grown in charcoal filtered and notfiltered Open Top Chambers in factorial combination with different levels of water supply. Measurements of biomass, leaf area and stomatal conductance were made during the growth period. Ozone injuries were estimated as not-filtered/filtered OTC yield ratio; the stomatal flux of ozone was estimated multiplying stomata conductance x diffusivity ratio between ozone and water vapour (0.613 x ozone hourly concentrations. The hourly values of ozone uptake were cumulated throughout the cropping periods of the two years. In the sensitive biotype, water stress reduced yield losses due to ozone from 38% to 22%, as well as yield losses due to water stress were reduced by the presence of ozone from 43% to 29%, while no interaction between ozone and water stress was observed in the resistant biotype. Biomass yield losses of the sensitive biotype were strictly correlated to cumulated ozone uptake (R2 = 0.99, while biomass yield losses of the resistant biotype were not affected by the ozone fluxes variations created by the treatments. Flux based models could better estimate yield losses due to ozone in Mediterranean environments in which other stresses could be contemporary present; therefore, the new European directives might replace the actual thresholds based

  7. Nitric oxide reduces oxidative damage induced by water stress in sunflower plants

    Directory of Open Access Journals (Sweden)

    Inês Cechin

    2015-06-01

    Full Text Available Drought is one of the main environmental constraints that can reduce plant yield. Nitric oxide (NO is a signal molecule involved in plant responses to several environmental stresses. The objective of this study was to investigate the cytoprotective effect of a single foliar application of 0, 1, 10 or 100 µM of the NO donor sodium nitroprusside (SNP in sunflower plants under water stress. Water stressed plants treated with 1μM SNP showed an increase in the relative water content compared with 0 μM SNP. Drought reduced the shoot dry weight but SNP applications did not result in alleviation of drought effects. Neither drought nor water stress plus SNP applications altered the content of photosynthetic pigments. Stomatal conductance was reduced by drought and this reduction was accompanied by a significant reduction in intercellular CO2 concentration and photosynthesis. Treatment with SNP did not reverse the effect of drought on the gas exchange characteristics. Drought increased the level of malondialdehyde (MDA and proline and reduced pirogalol peroxidase (PG-POD activity, but did not affect the activity of superoxide dismutase (SOD. When the water stressed plants were treated with 10 μM SNP, the activity of PG-POD and the content of proline were increased and the level of MDA was decreased. The results show that the adverse effects of water stress on sunflower plants are dependent on the external NO concentration. The action of NO may be explained by its ability to increase the levels of antioxidant compounds and the activity of ROS-scavenging enzymes.

  8. Gas exchanges and water use efficiency in the selection of tomato genotypes tolerant to water stress.

    Science.gov (United States)

    Borba, M E A; Maciel, G M; Fraga Júnior, E F; Machado Júnior, C S; Marquez, G R; Silva, I G; Almeida, R S

    2017-06-20

    Water stress can affect the yield in tomato crops and, despite this, there are few types of research aiming to select tomato genotypes resistant to the water stress using physiological parameters. This experiment aimed to study the variables that are related to the gas exchanges and the efficiency in water use, in the selection of tomato genotypes tolerant to water stress. It was done in a greenhouse, measuring 7 x 21 m, in a randomized complete block design, with four replications (blocks), being five genotypes in the F 2 BC 1 generation, which were previously obtained from an interspecific cross between Solanum pennellii versus S. lycopersicum and three check treatments, two susceptible [UFU-22 (pre-commercial line) and cultivar Santa Clara] and one resistant (S. pennellii). At the beginning of flowering, the plants were submitted to a water stress condition, through irrigation suspension. After that CO 2 assimilation, internal CO 2 , stomatal conductance, transpiration, leaf temperature, instantaneous water use efficiency, intrinsic efficiency of water use, instantaneous carboxylation efficiency, chlorophyll a and b, and the potential leaf water (Ψf) were observed. Almost all variables that were analyzed, except CO 2 assimilation and instantaneous carboxylation efficiency, demonstrated the superiority of the wild accession, S. pennellii, concerning the susceptible check treatments. The high photosynthetic rate and the low stomatal conductance and transpiration, presented by the UFU22/F 2 BC 1 #2 population, allowed a better water use efficiency. Because of that, these physiological characteristics are promising in the selection of tomato genotypes tolerant to water stress.

  9. The adsorption of α-amylase on barley proteins affects the in vitro digestion of starch in barley flour.

    Science.gov (United States)

    Yu, Wenwen; Zou, Wei; Dhital, Sushil; Wu, Peng; Gidley, Michael J; Fox, Glen P; Gilbert, Robert G

    2018-02-15

    The conversion of barley starch to sugars is a complex enzymic process. Most previous work concerned the biotechnical aspect of in situ barley enzymes. However, the interactions among the macromolecular substrates and their effects on enzymic catalysis has been little examined. Here, we explore the mechanisms whereby interactions of protein and starch in barley flour affect the kinetics of enzymatic hydrolysis of starch in an in vitro system, using digestion rate data and structural analysis by confocal microscopy. The degradation kinetics of both uncooked barley flour and of purified starches are found to be two-step sequential processes. Barley proteins, especially the water-soluble component, are found to retard the digestion of starch degraded by α-amylase: the enzyme binds with water-insoluble protein and with starch granules, leading to reduced starch hydrolysis. These findings are of potential industrial value in both the brewing and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Breeding of proanthocyanidin free malting barley

    International Nuclear Information System (INIS)

    Andersen, Anna Maria

    1990-01-01

    Full text: Haze formation in stored beer is due to colloidal precipitation of proteins with polyphenols of which proanthocyanidins are the most important group. 70-80% of proanthocyanidin in beer are from barley malt. Today breweries attain haze stability by using enzymes, additives or adsorbents. A better solution would be to remove proanthocyanidins. Carlsberg Plant Breeding uses induced mutations to breed proanthocyanidin-free malting barley. After mutagen treatment with sodium azide M1 seeds are planted in the field and M2 seeds are harvested in bulk. A single seed, non-destructive method has been developed to identify mutant kernels lacking proanthocyanidins in the testa. The method involves the inclusion of M2 seeds - 50 at a time - in semisolid clay blocks, whereafter a small part of the endosperm, testa and pericarp are exposed by sanding the seeds. The clay block is then placed in a vanillin-HCI solution so that the uncovered tissues can react with the solution. A red colour will develop in the testa of normal seeds, whereas the testa layers of proanthocyanid-free seeds remain colourless. So far, more than 600 mutants have been induced in over 100 barley varieties, spring as well as winter-types, from barley producing areas around the world. The mutants can be assigned to at least 7 loci, all of which can block the biosynthetic pathway for the proanthocyanidins. Mutants in the ant-18 and ant-19 loci show poor kernel development. Only a few mutants are known in the ant-12, ant-22 and ant-25 loci. Breeding work is focussed on mutants belonging to the ant-13 and ant-17 loci. Whereas the malting quality of ant-17 lines suffer from apparent abnormal enzyme development in the aleurone layer, this defect does not exist in ant-13 lines. Brewing trials with proanthocyanidin-free malt have shown excellent haze stability without changes in beer flavour. Breeding work based on the ant-13 lines led to disease resistant lines with good malting quality, while grain yield

  11. Replication of DNA during barley endosperm development

    DEFF Research Database (Denmark)

    Giese, H.

    1992-01-01

    The incorporation of [6-H-3]-thymidine into DNA of developing barley end sperm was examined by autoradiography of cross sections of seeds and DNA analysis. The majority of nuclear divisions took place in the very young endosperm, but as late as 25 days after anthesis there was evidence for DNA...... replication. The DNA content of the endosperm increases during development and in response to nitrogen application in parallel to the storage protein synthesis profile. The hordein genes were hypersensitive to DNase I treatment throughout development....

  12. The Barley Chromosome 5 Linkage Map

    DEFF Research Database (Denmark)

    Jensen, J.; Jørgensen, Jørgen Helms

    1975-01-01

    The distances between nine loci on barley chromosome 5 have been studied in five two-point tests, three three-point tests, and one four-point test. Our previous chromosome 5 linkage map, which contained eleven loci mapped from literature data (Jensen and Jørgensen 1975), is extended with four loci......-position is fixed on the map by a locus (necl), which has a good marker gene located centrally in the linkage group. The positions of the other loci are their distances in centimorgans from the 0-position; loci in the direction of the short chromosome arm are assigned positive values and those...

  13. Radiation induced desynaptic mutants in barley

    International Nuclear Information System (INIS)

    Srivastava, H.M.

    1974-01-01

    Spontaneous occurrence of asynapsis and desynapsis has been frequently reported in a number of crop plants (Beadle 1930, 1933; Beasley and Brown 1942; Li et al. 1945; Magoon et al. 1961; Miller 1963) and other angiospermic texa (Calarier 1955; Chennaveraiah and Krisnappa 1968; Ehrenberg 1949; Johnson 1941, 1944; Roy and Jha 1958). However, there are only a few reports of induced asynapsis or desynapsis (Gottschalk and Baquar 1971; Martini and Bozzini 1966). The present paper deals with the morphology and meiotic behavior of gamma-ray induced barley mutants showing high degree of desynapsis resulting in partial to complete sterility. (author)

  14. Post-fire wood management alters water stress, growth, and performance of pine regeneration in a Mediterranean ecosystem

    Science.gov (United States)

    Maranon-Jimenez, Sara; Castro, Jorge; Querejeta, José Ignacio; Fernandez-Ondono, Emilia; Allen, Craig D.

    2013-01-01

    Extensive research has focused on comparing the impacts of post-fire salvage logging versus those of less aggressive management practices on forest regeneration. However, few studies have addressed the effects of different burnt-wood management options on seedling/sapling performance, or the ecophysiological mechanisms underlying differences among treatments. In this study, we experimentally assess the effects of post-fire management of the burnt wood on the growth and performance of naturally regenerating pine seedlings (Pinus pinaster). Three post-fire management treatments varying in degree of intervention were implemented seven months after a high-severity wildfire burned Mediterranean pine forests in the Sierra Nevada, southeast Spain: (a) “No Intervention” (NI, all burnt trees left standing); (b) “Partial Cut plus Lopping” (PCL, felling most of the burnt trees, cutting off branches, and leaving all the biomass on site without mastication); and (c) “Salvage Logging” (SL, felling the burnt trees, piling up the logs and masticating the fine woody debris). Three years after the fire, the growth, foliar nutrient concentrations, and leaf carbon, nitrogen and oxygen isotopic composition (δ13C, δ18O and δ15N) of naturally regenerating seedlings were measured in all the treatments. Pine seedlings showed greatest vigor and size in the PCL treatment, whereas growth was poorest in SL. The nutrient concentrations were similar among treatments, although greater growth in the two treatments with residual wood present indicated higher plant uptake. Seedlings in the SL treatment showed high leaf δ13C and δ18O values indicating severe water stress, in contrast to significantly alleviated water stress indications in the PCL treatment. Seedling growth and physiological performance in NI was intermediate between that of PCL and SL. After six growing seasons, P. pinaster saplings in PCL showed greater growth and cone production than SL saplings. In summary

  15. The effect of water stress on some morphological, physiological, and biochemical characteristics and bud success on apple and quince rootstocks.

    Science.gov (United States)

    Bolat, Ibrahim; Dikilitas, Murat; Ercisli, Sezai; Ikinci, Ali; Tonkaz, Tahsin

    2014-01-01

    The effects of different water stress (control, medium, and severe) on some morphological, physiological, and biochemical characteristics and bud success of M9 apple and MA quince rootstocks were determined. The results showed that water stress significantly affected most morphological, physiological, and biochemical characteristics as well as budding success on the both rootstocks. The increasing water stress decreased the relative shoot length, diameter, and plant total fresh and dry weights. Leaf relative water content and chlorophyll index decreased while electrolyte leakage increased with the increase of water stress in both rootstocks. An increase in water stress also resulted in reduction in budding success in Vista Bella/M9 (79.33% and 46.67%) and Santa Maria/MA (70.33% and 15.33%) combinations. However, the water stress in Santa Maria/MA was more prominent. The increase in water stress resulted in higher peroxidase activities as well as phenol contents in both rootstocks. Although catalase activity, anthocyanin, and proline contents increased with the impact of stress, this was not statistically significant. The results suggest that the impact of stress increased with the increase of water stress; therefore, growers should be careful when using M9 and MA rootstocks in both nursery and orchards where water scarcity is present.

  16. The Effect of Water Stress on Some Morphological, Physiological, and Biochemical Characteristics and Bud Success on Apple and Quince Rootstocks

    Directory of Open Access Journals (Sweden)

    Ibrahim Bolat

    2014-01-01

    Full Text Available The effects of different water stress (control, medium, and severe on some morphological, physiological, and biochemical characteristics and bud success of M9 apple and MA quince rootstocks were determined. The results showed that water stress significantly affected most morphological, physiological, and biochemical characteristics as well as budding success on the both rootstocks. The increasing water stress decreased the relative shoot length, diameter, and plant total fresh and dry weights. Leaf relative water content and chlorophyll index decreased while electrolyte leakage increased with the increase of water stress in both rootstocks. An increase in water stress also resulted in reduction in budding success in Vista Bella/M9 (79.33% and 46.67% and Santa Maria/MA (70.33% and 15.33% combinations. However, the water stress in Santa Maria/MA was more prominent. The increase in water stress resulted in higher peroxidase activities as well as phenol contents in both rootstocks. Although catalase activity, anthocyanin, and proline contents increased with the impact of stress, this was not statistically significant. The results suggest that the impact of stress increased with the increase of water stress; therefore, growers should be careful when using M9 and MA rootstocks in both nursery and orchards where water scarcity is present.

  17. Parental Leave in Denmark

    DEFF Research Database (Denmark)

    Rostgaard, Tine; Christoffersen, Mogens; Weise, Hanne

    This artcle considders the political aims for different leave schemes and reviews studies af these schemes. The use of parental leave is sensitive to the financial loss involved in taking leave: a decrease in the benefit payments has had a significant influence on take-up, while, in general, fami......, families'' loss of income is less if leave is taken up by the mothers. Only few fathers participate in parental leave....

  18. Observing plants dealing with soil water stress: Daily soil moisture fluctuations derived from polymer tensiometers

    Science.gov (United States)

    van der Ploeg, Martine; de Rooij, Gerrit

    2014-05-01

    Periods of soil water deficit often occur within a plant's life cycle, even in temperate deciduous and rain forests (Wilson et al. 2001, Grace 1999). Various experiments have shown that roots are able to sense the distribution of water in the soil, and produce signals that trigger changes in leaf expansion rate and stomatal conductance (Blackman and Davies 1985, Gollan et al. 1986, Gowing et al. 1990 Davies and Zhang 1991, Mansfield and De Silva 1994, Sadras and Milroy 1996). Partitioning of water and air in the soil, solute distribution in soil water, water flow through the soil, and water availability for plants can be determined according to the distribution of the soil water potential (e.g. Schröder et al. 2013, Kool et al. 2014). Understanding plant water uptake under dry conditions has been compromised by hydrological instrumentation with low accuracy in dry soils due to signal attenuation, or a compromised measurement range (Whalley et al. 2013). Development of polymer tensiometers makes it possible to study the soil water potential over a range meaningful for studying plant responses to water stress (Bakker et al. 2007, Van der Ploeg et al. 2008, 2010). Polymer tensiometer data obtained from a lysimeter experiment (Van der Ploeg et al. 2008) were used to analyse day-night fluctuations of soil moisture in the vicinity of maize roots. To do so, three polymer tensiometers placed in the middle of the lysimeter from a control, dry and very dry treatment (one lysimeter per treatment) were used to calculate water content changes over 12 hours. These 12 hours corresponded with the operation of the growing light. Soil water potential measurements in the hour before the growing light was turned on or off were averaged. The averaged value was used as input for the van Genuchten (1980) model. Parameters for the model were obtained from laboratory determination of water retention, with a separate model parameterization for each lysimeter setup. Results show daily

  19. The Importance of Barley Varieties in terms of Production, Marketing and Processing

    Directory of Open Access Journals (Sweden)

    Rahmi Taşcı

    2017-08-01

    Full Text Available In this study, it is aimed to investigate the criteria affecting the marketing of barley in the stages of barley production, marketing and processing in Konya province. In the study; survey results were used which get from mixed feed (37 items and malt factory (1 item, traders (50 items purchasing and selling barley, and agricultural enterprises (107 items including barley production in agricultural activities operating in Konya province. It was determined that barley varieties were not an important criterion in the selling price, while the hectoliter and other plant species do not mix into barley are the main criteria considered by agricultural enterprises to affect the sale of barley. The most important criteria that traders keep in mind when buying barley is hectoliter of barley, which is followed by moisture, colour and foreign matter confusion rate of barley. The most important criteria that factories take into consideration when purchasing barley is determined as the moisture content of the barley, followed by the hectoliter of barley and the rate of foreign matter contamination. For the malt industry; Barley variety is a very important factor in the purchase criteria, followed by barley humidity and colour.

  20. Characterization of volatile aroma compounds in different brewing barley cultivars.

    Science.gov (United States)

    Dong, Liang; Hou, Yingmin; Li, Feng; Piao, Yongzhe; Zhang, Xiao; Zhang, Xiaoyu; Li, Cheng; Zhao, Changxin

    2015-03-30

    Beer is a popular alcoholic malt beverage resulting from fermentation of the aqueous extract of malted barley with hops. The aroma of brewing barley impacts the flavor of beer indirectly, because some flavor compounds or their precursors in beer come from the barley. The objectives of this research were to study volatile profiles and to characterize odor-active compounds of brewing barley in order to determine the variability of the aroma composition among different brewing barley cultivars. Forty-one volatiles comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds and furans were identified using solid phase microextraction combined with gas chromatography/mass spectrometry, among which aldehydes, alcohols and ketones were quantitatively in greatest abundance. Quantitative measurements performed by means of solvent extraction and calculation of odor activity values revealed that acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, heptanal, octanal, nonanal, 3-methyl-1-butanol, cyclopentanol, 2,3-butanedione, 2,3-pentanedione, 2-heptanone, acetic acid, ethyl acetate, 2-pentylfuran and benzeneacetaldehyde, whose concentrations exceeded their odor thresholds, could be considered as odor-active compounds of brewing barley. Principal component analysis was employed to evaluate the differences among cultivars. The results demonstrated that the volatile profile based on the concentrations of aroma compounds enabled good differentiation of most barley cultivars. © 2014 Society of Chemical Industry.

  1. Analysis of the arabinoxylan arabinofuranohydrolase gene family in barley does not support their involvement in the remodelling of endosperm cell walls during development.

    Science.gov (United States)

    Laidlaw, Hunter K C; Lahnstein, Jelle; Burton, Rachel A; Fincher, Geoffrey B; Jobling, Stephen A

    2012-05-01

    Arabinoxylan arabinofuranohydrolases (AXAHs) are family GH51 enzymes that have been implicated in the removal of arabinofuranosyl residues from the (1,4)-β-xylan backbone of heteroxylans. Five genes encoding barley AXAHs range in size from 4.6 kb to 7.1 kb and each contains 16 introns. The barley HvAXAH genes map to chromosomes 2H, 4H, and 5H. A small cluster of three HvAXAH genes is located on chromosome 4H and there is evidence for gene duplication and the presence of pseudogenes in barley. The cDNAs corresponding to barley and wheat AXAH genes were cloned, and transcript levels of the genes were profiled across a range of tissues at different developmental stages. Two HvAXAH cDNAs that were successfully expressed in Nicotiana benthamiana leaves exhibited similar activities against 4-nitrophenyl α-L-arabinofuranoside, but HvAXAH2 activity was significantly higher against wheat flour arabinoxylan, compared with HvAXAH1. HvAXAH2 also displayed activity against (1,5)-α-L-arabinopentaose and debranched arabinan. Western blotting with an anti-HvAXAH antibody was used to define further the locations of the AXAH enzymes in developing barley grain, where high levels were detected in the outer layers of the grain but little or no protein was detected in the endosperm. The chromosomal locations of the genes do not correspond to any previously identified genomic regions shown to influence heteroxylan structure. The data are therefore consistent with a role for AXAH in depolymerizing arabinoxylans in maternal tissues during grain development, but do not provide compelling evidence for a role in remodelling arabinoxylans during endosperm or coleoptile development in barley as previously proposed.

  2. Useful mutations in Iraqi black barley

    International Nuclear Information System (INIS)

    Ibrahim, I.F.

    1989-01-01

    Full text: Barley (Hordeum vulgare L.) is an important fodder crop in Iraq, with a cultivated area of about 1 392 375 ha and a total production of about 838500 t. The 2-row black barley ''LBB'' is the most desirable one in semi-arid zone in northern part of Iraq, because of its drought tolerance and high protein content. However, this cultivar is susceptible to powdery mildew, and lodges. Gamma rays and EMS were used to induce mutations in ''LBB'' and its hybrid with A rivat''. Nine mutants with improved lodging were selected during the first six generations. Five mutants INRC-BB-1, INRC-BB-3, INRC-BBR-4A, INRC-HB-552 and INRC-HB-553 were resistant to powdery mildew while 2 mutants INRC-BBH-1 and INRC-HBR-3 were moderately resistant. Two mutants INRC-BB-123 and INRC-HBR-3 were also resistant to drought under 350-400 mm rainfall. Three mutants INRC-BB-1, INRC-HBR-3 and INRC-HBR-88 exceeded their original variety in seed weight per spike and TKW. (author)

  3. Influence of Leaf Tolerance Mechanisms and Rain on Boron Toxicity in Barley and Wheat1[C

    Science.gov (United States)

    Reid, Rob; Fitzpatrick, Kate

    2009-01-01

    Boron (B) toxicity is common in many areas of the world. Plant tolerance to high B varies widely and has previously been attributed to reduced uptake of B, most commonly as a result of B efflux from roots. In this study, it is shown that the expression of genes encoding B efflux transporters in leaves of wheat (Triticum aestivum) and barley (Hordeum vulgare) is associated with an ability of leaf tissues to withstand higher concentrations of B. In tolerant cultivars, necrosis in leaves occurred at B concentrations more than 2-fold higher than in sensitive cultivars. It is hypothesized that this leaf tolerance is achieved via redistribution of B by efflux transporters from sensitive symplastic compartments into the leaf apoplast. Measurements of B concentrations in leaf protoplasts, and of B released following infiltration of leaves, support this hypothesis. It was also shown that under B-toxic conditions, leaching of B from leaves by rain had a strong positive effect on growth of both roots and shoots. Measurements of rates of guttation and the concentration of B in guttation droplets indicated that the impact of guttation on the alleviation of B toxicity would be small. PMID:19625636

  4. An improved approach for remotely sensing water stress impacts on forest C uptake.

    Science.gov (United States)

    Sims, Daniel A; Brzostek, Edward R; Rahman, Abdullah F; Dragoni, Danilo; Phillips, Richard P

    2014-09-01

    Given that forests represent the primary terrestrial sink for atmospheric CO2 , projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy 'greenness' (e.g., normalized difference vegetation index; NDVI). However, many forests have low spectral sensitivity to water stress (SSWS) - defined here as drought-induced decline in GPP without a change in greenness. Current satellite-derived estimates of GPP use a vapor pressure deficit (VPD) scalar to account for the low SWSS of forests, but fail to capture their responses to water stress. Our objectives were to characterize differences in SSWS among forested and nonforested ecosystems, and to develop an improved framework for predicting the impacts of water stress on GPP in forests with low SSWS. First, we paired two independent drought indices with NDVI data for the conterminous US from 2000 to 2011, and examined the relationship between water stress and NDVI. We found that forests had lower SSWS than nonforests regardless of drought index or duration. We then compared satellite-derived estimates of GPP with eddy-covariance observations of GPP in two deciduous broadleaf forests with low SSWS: the Missouri Ozark (MO) and Morgan Monroe State Forest (MMSF) AmeriFlux sites. Model estimates of GPP that used VPD scalars were poorly correlated with observations of GPP at MO (r(2) = 0.09) and MMSF (r(2) = 0.38). When we included the NDVI responses to water stress of adjacent ecosystems with high SSWS into a model based solely on temperature and greenness, we substantially improved predictions of GPP at MO (r(2) = 0.83) and for a severe drought year at the MMSF (r(2) = 0.82). Collectively, our results suggest that large-scale estimates of GPP that capture variation in SSWS among ecosystems could improve predictions of C uptake by forests under drought. © 2014 John Wiley & Sons

  5. Linking waterlogging tolerance with Mn²⁺ toxicity: a case study for barley.

    Science.gov (United States)

    Huang, X; Shabala, S; Shabala, L; Rengel, Z; Wu, X; Zhang, G; Zhou, M

    2015-01-01

    Vast agricultural areas are affected by flooding, causing up to 80% yield reduction and resulting in multibillion dollar losses. Up to now, the focus of plant breeders was predominantly on detrimental effects of anoxia, while other (potentially equally important) traits were essentially neglected; one of these is soil elemental toxicity. Excess water triggers a progressive decrease in soil redox potential, thus increasing the concentration of Mn(2+) that can be toxic to plants if above a specific threshold. This work aimed to quantify the relative contribution of Mn(2+) toxicity to waterlogging stress tolerance, using barley as a case study. Twenty barley (Hordeum vulgare) genotypes contrasting in waterlogging stress tolerance were studied for their ability to cope with toxic (1 mm) amounts of Mn(2+) in the root rhizosphere. Under Mn(2+) toxicity, chlorophyll content of most waterlogging-tolerant genotypes (TX9425, Yerong, CPI-71284-48 and CM72) remained above 60% of the control value, whereas sensitive genotypes (Franklin and Naso Nijo) had 35% less chlorophyll than 35% of controls. Manganese concentration in leaves was not related to visual Mn(2+) toxicity symptoms, suggesting that various Mn(2+) tolerance mechanisms might operate in different tolerant genotypes, i.e. avoidance versus tissue tolerance. The overall significant (r = 0.60) correlation between tolerance to Mn(2+) toxicity and waterlogging in barley suggests that plant breeding for tolerance to waterlogging traits may be advanced by targeting mechanisms conferring tolerance to Mn(2+) toxicity, at least in this species. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Allelic barley MLA immune receptors recognize sequence-unrelated avirulence effectors of the powdery mildew pathogen.

    Science.gov (United States)

    Lu, Xunli; Kracher, Barbara; Saur, Isabel M L; Bauer, Saskia; Ellwood, Simon R; Wise, Roger; Yaeno, Takashi; Maekawa, Takaki; Schulze-Lefert, Paul

    2016-10-18

    Disease-resistance genes encoding intracellular nucleotide-binding domain and leucine-rich repeat proteins (NLRs) are key components of the plant innate immune system and typically detect the presence of isolate-specific avirulence (AVR) effectors from pathogens. NLR genes define the fastest-evolving gene family of flowering plants and are often arranged in gene clusters containing multiple paralogs, contributing to copy number and allele-specific NLR variation within a host species. Barley mildew resistance locus a (Mla) has been subject to extensive functional diversification, resulting in allelic resistance specificities each recognizing a cognate, but largely unidentified, AVR a gene of the powdery mildew fungus, Blumeria graminis f. sp. hordei (Bgh). We applied a transcriptome-wide association study among 17 Bgh isolates containing different AVR a genes and identified AVR a1 and AVR a13 , encoding candidate-secreted effectors recognized by Mla1 and Mla13 alleles, respectively. Transient expression of the effector genes in barley leaves or protoplasts was sufficient to trigger Mla1 or Mla13 allele-specific cell death, a hallmark of NLR receptor-mediated immunity. AVR a1 and AVR a13 are phylogenetically unrelated, demonstrating that certain allelic MLA receptors evolved to recognize sequence-unrelated effectors. They are ancient effectors because corresponding loci are present in wheat powdery mildew. AVR A1 recognition by barley MLA1 is retained in transgenic Arabidopsis, indicating that AVR A1 directly binds MLA1 or that its recognition involves an evolutionarily conserved host target of AVR A1 Furthermore, analysis of transcriptome-wide sequence variation among the Bgh isolates provides evidence for Bgh population structure that is partially linked to geographic isolation.

  7. No Time to Waste: Transcriptome Study Reveals that Drought Tolerance in Barley May Be Attributed to Stressed-Like Expression Patterns that Exist before the Occurrence of Stress.

    Science.gov (United States)

    Janiak, Agnieszka; Kwasniewski, Miroslaw; Sowa, Marta; Gajek, Katarzyna; Żmuda, Katarzyna; Kościelniak, Janusz; Szarejko, Iwona

    2017-01-01

    Plant survival in adverse environmental conditions requires a substantial change in the metabolism, which is reflected by the extensive transcriptome rebuilding upon the occurrence of the stress. Therefore, transcriptomic studies offer an insight into the mechanisms of plant stress responses. Here, we present the results of global gene expression profiling of roots and leaves of two barley genotypes with contrasting ability to cope with drought stress. Our analysis suggests that drought tolerance results from a certain level of transcription of stress-influenced genes that is present even before the onset of drought. Genes that predispose the plant to better drought survival play a role in the regulatory network of gene expression, including several transcription factors, translation regulators and structural components of ribosomes. An important group of genes is involved in signaling mechanisms, with significant contribution of hormone signaling pathways and an interplay between ABA, auxin, ethylene and brassinosteroid homeostasis. Signal transduction in a drought tolerant genotype may be more efficient through the expression of genes required for environmental sensing that are active already during normal water availability and are related to actin filaments and LIM domain proteins, which may function as osmotic biosensors. Better survival of drought may also be attributed to more effective processes of energy generation and more efficient chloroplasts biogenesis. Interestingly, our data suggest that several genes involved in a photosynthesis process are required for the establishment of effective drought response not only in leaves, but also in roots of barley. Thus, we propose a hypothesis that root plastids may turn into the anti-oxidative centers protecting root macromolecules from oxidative damage during drought stress. Specific genes and their potential role in building up a drought-tolerant barley phenotype is extensively discussed with special emphasis

  8. No Time to Waste: Transcriptome Study Reveals that Drought Tolerance in Barley May Be Attributed to Stressed-Like Expression Patterns that Exist before the Occurrence of Stress

    Directory of Open Access Journals (Sweden)

    Agnieszka Janiak

    2018-01-01

    Full Text Available Plant survival in adverse environmental conditions requires a substantial change in the metabolism, which is reflected by the extensive transcriptome rebuilding upon the occurrence of the stress. Therefore, transcriptomic studies offer an insight into the mechanisms of plant stress responses. Here, we present the results of global gene expression profiling of roots and leaves of two barley genotypes with contrasting ability to cope with drought stress. Our analysis suggests that drought tolerance results from a certain level of transcription of stress-influenced genes that is present even before the onset of drought. Genes that predispose the plant to better drought survival play a role in the regulatory network of gene expression, including several transcription factors, translation regulators and structural components of ribosomes. An important group of genes is involved in signaling mechanisms, with significant contribution of hormone signaling pathways and an interplay between ABA, auxin, ethylene and brassinosteroid homeostasis. Signal transduction in a drought tolerant genotype may be more efficient through the expression of genes required for environmental sensing that are active already during normal water availability and are related to actin filaments and LIM domain proteins, which may function as osmotic biosensors. Better survival of drought may also be attributed to more effective processes of energy generation and more efficient chloroplasts biogenesis. Interestingly, our data suggest that several genes involved in a photosynthesis process are required for the establishment of effective drought response not only in leaves, but also in roots of barley. Thus, we propose a hypothesis that root plastids may turn into the anti-oxidative centers protecting root macromolecules from oxidative damage during drought stress. Specific genes and their potential role in building up a drought-tolerant barley phenotype is extensively discussed

  9. γ-ray radiation decontamination of barley plant powder

    International Nuclear Information System (INIS)

    Zhao Xiaojun; Fu Junjie; Wang Zhiping; Zhang Guobin

    2007-01-01

    Radiation decontamination of barley plant powder by 60 Co γ-rays and the effect on its components were studied. Results showed that irradiation was very effective in killing the microorganisms in barley plant powder. The irradiation did not cause obvious changes of the major components of protein, total sugar, free amino acid, crude fiber, but 35% loss of vitamin E was observed after 10kGy irradiation. It is suggested that 7.5-10kGy irradiation is good enough for decontamination of the barley plant powder. (authors)

  10. Oligosaccharide binding to barley alpha-amylase 1

    DEFF Research Database (Denmark)

    Robert, X.; Haser, R.; Mori, H.

    2005-01-01

    Enzymatic subsite mapping earlier predicted 10 binding subsites in the active site substrate binding cleft of barley alpha-amylase isozymes. The three-dimensional structures of the oligosaccharide complexes with barley alpha-amylase isozyme 1 (AMY1) described here give for the first time a thorough...... in barley alpha-amylase isozyme 2 (AMY2), and the sugar binding modes are compared between the two isozymes. The "sugar tongs" surface binding site discovered in the AMY1-thio-DP4 complex is confirmed in the present work. A site that putatively serves as an entrance for the substrate to the active site...

  11. INVITRO DIGESTIBILITY OF PROTEIN FROM BARLEY AND OTHER CEREALS

    DEFF Research Database (Denmark)

    Buchmann, N. B.

    1979-01-01

    An in vitro method for measuring barley protein digestibility is presented. Samples were first incubated with pepsin in HCl; pancreatin was then added concomitantly with a bacteriostatic borate buffer. After TCA-precipitation, soluble nitrogen was measured. The digestion was unaffected...... by accumulated free amino acids. There were no free amino acids following pepsin treatment, but the essential ones were well liberated by pancreatin. Results for barley grown in the field or in pots, and for decortified barley fractions agreed with true digestibility values determined with rats. Of these samples...... digestibility depended on the type of enzyme and on the enzyme-to-substrate ratio....

  12. The β-Ketoacyl-CoA Synthase HvKCS1, Encoded by Cer-zh, Plays a Key Role in Synthesis of Barley Leaf Wax and Germination of Barley Powdery Mildew.

    Science.gov (United States)

    Li, Chao; Haslam, Tegan M; Krüger, Anna; Schneider, Lizette M; Mishina, Kohei; Samuels, Lacey; Yang, Hongxing; Kunst, Ljerka; Schaffrath, Ulrich; Nawrath, Christiane; Chen, Guoxiong; Komatsuda, Takao; von Wettstein-Knowles, Penny

    2018-04-01

    The cuticle coats the primary aerial surfaces of land plants. It consists of cutin and waxes, which provide protection against desiccation, pathogens and herbivores. Acyl cuticular waxes are synthesized via elongase complexes that extend fatty acyl precursors up to 38 carbons for downstream modification pathways. The leaves of 21 barley eceriferum (cer) mutants appear to have less or no epicuticular wax crystals, making these mutants excellent tools for identifying elongase and modification pathway biosynthetic genes. Positional cloning of the gene mutated in cer-zh identified an elongase component, β-ketoacyl-CoA synthase (CER-ZH/HvKCS1) that is one of 34 homologous KCSs encoded by the barley genome. The biochemical function of CER-ZH was deduced from wax and cutin analyses and by heterologous expression in yeast. Combined, these experiments revealed that CER-ZH/HvKCS1 has a substrate specificity for C16-C20, especially unsaturated, acyl chains, thus playing a major role in total acyl chain elongation for wax biosynthesis. The contribution of CER-ZH to water barrier properties of the cuticle and its influence on the germination of barley powdery mildew fungus were also assessed.

  13. Direct observation of local xylem embolisms induced by soil drying in intact Zea mays leaves.

    Science.gov (United States)

    Ryu, Jeongeun; Hwang, Bae Geun; Kim, Yangmin X; Lee, Sang Joon

    2016-04-01

    The vulnerability of vascular plants to xylem embolism is closely related to their stable long-distance water transport, growth, and survival. Direct measurements of xylem embolism are required to understand what causes embolism and what strategies plants employ against it. In this study, synchrotron X-ray microscopy was used to non-destructively investigate both the anatomical structures of xylem vessels and embolism occurrence in the leaves of intact Zea mays (maize) plants. Xylem embolism was induced by water stress at various soil drying periods and soil water contents. X-ray images of dehydrated maize leaves showed that the ratio of gas-filled vessels to all xylem vessels increased with decreased soil water content and reached approximately 30% under severe water stress. Embolism occurred in some but not all vessels. Embolism in maize leaves was not strongly correlated with xylem diameter but was more likely to occur in the peripheral veins. The rate of embolism formation in metaxylem vessels was higher than in protoxylem vessels. This work has demonstrated that xylem embolism remains low in maize leaves under water stress and that there xylem has characteristic spatial traits of vulnerability to embolism. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Functional Analysis of Barley Powdery Mildew Effector Candidates and Identification of their Barley Targets

    DEFF Research Database (Denmark)

    Ahmed, Ali Abdurehim

    The genome of barley powdery mildew fungus (Blumeria graminis f. sp. hordei, Bgh) encodes around 500 Candidate Secreted Effector Proteins (CSEPs), which are believed to be delivered to the barley cells either to interfere with plant defence and/or promote nutrient uptake. So far, little is known...... about the function of many CSEPs in virulence and the identities of their host targets. In this PhD study, we investigated the function of nine CSEPs and found that CSEP0081, CSEP0105, CSEP0162 and CSEP0254 act as effectors by promoting the Bgh infection success. Independent silencing of these CSEPs...... proteins (sHsps), Hsp16.9 and Hsp17.5, were identified as interactors for both CSEP0105 and CSEP0162. These interactions were confirmed in planta by BiFC and co-localization studies. Small heat shock proteins are highly conserved ATP-independent chaperones that protect the cell from stress-induced protein...

  15. Assessment of Salicylic Acid Impacts on Seedling Characteristic of Cucumber (Cucumis sativus L. under Water Stress

    Directory of Open Access Journals (Sweden)

    Hossein MARDANI

    2012-02-01

    Full Text Available Impacts of various concentrations of salicylic acid (SA on cucumber (Cucumis sativus L. seedling characteristic were evaluated under different water stress levels by using a factorial arrangement based on completely randomized design with three replications at experimental greenhouse of Ferdowsi University of Mashhad, Iran. The studied factors included three water deficit levels (100% FC, 80% FC, and 60% FC considered as first factor and five levels of SA concentrations (0, 0.25, 0.5, 0.75, and 1 mM as second factor. Results showed that foliar application of SA at the highest concentration enhanced leaf area, leaf and dry weight while decreased stomatal conductance under high level of water deficit stress. Though, severe water deficit stress sharply raised the SPAD reading values. In general, exogenous SA application could develop cucumber seedling characteristic and improve water stress tolerance.

  16. Structural relationships among central cell and egg apparatus cells of barley as related to transmission of male gametes

    Directory of Open Access Journals (Sweden)

    David D. Cass

    2014-01-01

    Full Text Available Barley embryo sacs were examined using light and electron microscopy before and during fertilization. One synergid degenerates after pollination with loss of nuclear and cytoplasmic organization and cell wall material between synergid and central cell. Some wall between egg and central cell is also lost. After pollen tube discharge into the degenerate synergid, the male gametes leave the synergid entering a pocket of central cell cytoplasm separated from the synergid only by membranes. This could provide for efficient gamete transmission and possible recognition through specific membrane contacts.

  17. Effects of INH, DNP, 2,4-D and CMU on the photosynthetic activity of barley and maize plants

    International Nuclear Information System (INIS)

    Fernandez, J.; Prieto, M. P.

    1979-01-01

    Determinations of the rate of photosynthesis were made in barley and maize leaves treated with INH, DNP, 2,4-D or CMU. 1 ppm of the chemicals in nutritive solutions was absorbed by roots during 24 or 48 hours in both dark and light conditions. After this period, photosynthetic activity, compensation point and 14 C O 2 assimilation were determined. Results show that INH increases the rate of photosynthesis, DNP and 2,4-D do not alter it sensibly and CMU acts as a strong inhibitor of photosynthesis. Some possible applications for ths obtention of labelled compounds by biosynthesis are discussed. (Author) 87 refs

  18. Physiological behaviors and recovery responses of four Galician grapevine (Vitis vinifera L. ) cultivars under water stress

    OpenAIRE

    Islam, M.; Berrios, J.

    2012-01-01

    Gas exchange parameters and chlorophyll fluorescence of four pot grown Galician grapevines (Vitis vinifera L. cv. Albariño, Brancellao, Godello and Treixadura) were examined under different levels of water stress in greenhouse. After extreme stress, gas exchange recovery responses were evaluated. Average ΨPD for control and stressed plants were -0.4MPa and -1.45MPa respectively. All varieties showed gradual declining of all gas exchange parameters (gs, E and A) with increasing of stress perio...

  19. Impact of water stress on growth reserves and re-growth of Themeda ...

    African Journals Online (AJOL)

    Four water stress treatments (T1 = 0–25%, T2 = 25–50%, T3 = 50–75% and T4 = 75–100% depletion of plant available water) were applied to the plants in pots in a glasshouse. The TNCC declined drastically after severe defoliation over all the water treatments (P < 0.05), in all the plant parts (P < 0.05) and for all the growth ...

  20. Electrophysiological assessment of water stress in fruit-bearing woody plants.

    Science.gov (United States)

    Ríos-Rojas, Liliana; Tapia, Franco; Gurovich, Luis A

    2014-06-15

    Development and evaluation of a real-time plant water stress sensor, based on the electrophysiological behavior of fruit-bearing woody plants is presented. Continuous electric potentials are measured in tree trunks for different irrigation schedules, inducing variable water stress conditions; results are discussed in relation to soil water content and micro-atmospheric evaporative demand, determined continuously by conventional sensors, correlating this information with tree electric potential measurements. Systematic and differentiable patterns of electric potentials for water-stressed and no-stressed trees in 2 fruit species are presented. Early detection and recovery dynamics of water stress conditions can also be monitored with these electrophysiology sensors, which enable continuous and non-destructive measurements for efficient irrigation scheduling throughout the year. The experiment is developed under controlled conditions, in Faraday cages located at a greenhouse area, both in Persea americana and Prunus domestica plants. Soil moisture evolution is controlled using capacitance sensors and solar radiation, temperature, relative humidity, wind intensity and direction are continuously registered with accurate weather sensors, in a micro-agrometeorological automatic station located at the experimental site. The electrophysiological sensor has two stainless steel electrodes (measuring/reference), inserted on the stem; a high precision Keithley 2701 digital multimeter is used to measure plant electrical signals; an algorithm written in MatLab(®), allows correlating the signal to environmental variables. An electric cyclic behavior is observed (circadian cycle) in the experimental plants. For non-irrigated plants, the electrical signal shows a time positive slope and then, a negative slope after restarting irrigation throughout a rather extended recovery process, before reaching a stable electrical signal with zero slope. Well-watered plants presented a

  1. Water stress and social vulnerability in the southern United States, 2010-2040

    Science.gov (United States)

    cassandra Johnson-Gaither; John Schelhas; Wayne Zipperer; Ge Sun; Peter V. Caldwell; Neelam Poudyal

    2014-01-01

    Water scarcities are striking in semiarid, subregions of the Southern United States such as Oklahoma and western Texas (Glennon 2009, Sabo et al. 2010). In Texas, water stress has been a constant concern since the 1950s when the state experienced severe drought conditions (Moore 2005). The nearly 2000-mile Rio Grande River, which forms part of the Texas–Mexico border,...

  2. Effect of phytase supplementation to barley-canola meal and barley-soybean meal diets on phosphorus and calcium balance in growing pigs

    NARCIS (Netherlands)

    Sauer, W.C.; Cervantes, M.; He, J.M.M.; Schulze, H.

    2003-01-01

    Two metabolism experiments were carried out, to determine the effect of microbial phytase addition to barley-canola meal and barley-soybean meal diets on P and Ca balance in growing. pigs; In experiment 1, six barrows (29.6kg: initial LW) were fed a barley-canola meal diet, without or. with phytase

  3. Physiological changes of pepper accessions in response to salinity and water stress

    Energy Technology Data Exchange (ETDEWEB)

    López-Serrano, L.; Penella, C.; San Bautista, A.; López-Galarza, S.; Calatayud, A.

    2017-07-01

    New sources of water stress and salinity tolerances are needed for crops grown in marginal lands. Pepper is considered one of the most important crops in the world. Many varieties belong to the genus Capsicum spp., and display wide variability in tolerance/sensitivity terms in response to drought and salinity stress. The objective was to screen seven salt/drought-tolerant pepper accessions to breed new cultivars that could overcome abiotic stresses, or be used as new crops in land with water and salinity stress. Fast and effective physiological traits were measured to achieve the objective. The present study showed wide variability of the seven pepper accessions in response to both stresses. Photosynthesis, stomatal conductance and transpiration reduced mainly under salinity due to stomatal and non-stomatal (Na+ accumulation) constraints and, to a lesser extent, in the accessions grown under water stress. A positive relationship between CO2 fixation and fresh weight generation was observed for both stresses. Decreases in Ys and YW and increased proline were observed only when accessions were grown under salinity. However, these factors were not enough to alleviate salt effects and an inverse relation was noted between plant salt tolerance and proline accumulation. Under water stress, A31 was the least affected and A34 showed the best tolerance to salinity in terms of photosynthesis and biomass.

  4. Water Stress Affects Development Time but Not Takeoff Performance in the Butterfly Pararge aegeria.

    Science.gov (United States)

    Lailvaux, Simon P; Breuker, Casper J; Van Damme, Raoul

    Most organisms are limited in the amount and type of resources they are able to extract from the environment. The juvenile environment is particularly important in this regard, as conditions over ontogeny can influence the adult phenotype. Whole-organism performance traits, such as locomotion, are susceptible to such environmental effects, yet the specific biotic and abiotic factors driving performance plasticity have received little attention. We tested whether speckled wood Pararge aegeria L. butterflies reared under conditions of water stress exhibited poorer flight morphology and performance than control individuals. Despite large differences in mortality between treatments, we found no effects of water stress treatment on takeoff performance and only minor treatment effects on flight morphology. However, butterflies reared on water-stressed diets exhibited both significantly greater mortality and longer development times than did control individuals. Pararge aegeria larvae may compensate for this stress by prolonging development, resulting in similar realized performance capacities at least in takeoff performance in surviving adult butterflies; other measures of flight performance remain to be considered. Alternatively, the adult phenotype may be insulated from environmental effects at the larval stage in these insects.

  5. water stress mediated changes in growth, physiology and secondary metabolites of desi ajwain (trachyspermum ammi l.)

    International Nuclear Information System (INIS)

    Azhar, N.; Hussain, B.; Abbasi, K.Y.

    2011-01-01

    Biotic and abiotic stresses exert a considerable influence on the production of several secondary metabolites in plants; water stress is one of the most important abiotic stress factors. This study was carried out to elucidate the effect of drought stress on growth, physiology and secondary metabolite production in desi ajwain (Trachyspermum ammi L.). Plants were grown in pots and three drought levels (100%, 80% and 60%) of field capacity were created. The experiment was laid out in complete randomized design (CRD) with three replicates. Data on growth, physiological and biochemical parameters were recorded and analyzed statistically. Physiological parameters like transpiration rate and stomatal conductance decreased concentration increased. The photosynthetic rate showed significantly with increasing water stress levels, but internal CO/sub 2/ non-significant reduction from 100% field capacity to 80% field capacity but increased at 60% field capacity. Growth parameters including plant height, herb fresh and dry weights were reduced significantly with increasing stress levels, while total phenolic contents and chlorophyll contents increased under water stress conditions. These results suggest that cultivation of medicinal plants like desi ajwain under drought stress could enhance the production of secondary metabolites. (author)

  6. Water stress, water salience, and the implications for water supply planning

    Science.gov (United States)

    Garcia, M. E.; Islam, S.

    2017-12-01

    Effectively addressing the water supply challenges posed by urbanization and climate change requires a holistic understanding of the water supply system, including the impact of human behavior on system dynamics. Decision makers have limits to available information and information processing capacity, and their attention is not equally distributed among risks. The salience of a given risk is higher when increased attention is directed to it and though perceived risk may increase, real risk does not change. Relevant to water supply planning is how and when water stress results in an increased salience of water risks. This work takes a socio-hydrological approach to develop a water supply planning model that includes water consumption as an endogenous variable, in the context of Las Vegas, NV. To understand the benefits and limitations of this approach, this model is compared to a traditional planning model that uses water consumption scenarios. Both models are applied to project system reliability and water stress under four streamflow and demographic scenarios, and to assess supply side responses to changing conditions. The endogenous demand model enables the identification of feedback between both supply and demand management decisions on future water consumption and system performance. This model, while specific to the Las Vegas case, demonstrates a prototypical modeling framework capable of examining water-supply demand interactions by incorporating water stress driven conservation.

  7. Modelling Water Stress in a Shiraz Vineyard Using Hyperspectral Imaging and Machine Learning

    Directory of Open Access Journals (Sweden)

    Kyle Loggenberg

    2018-01-01

    Full Text Available The detection of water stress in vineyards plays an integral role in the sustainability of high-quality grapes and prevention of devastating crop loses. Hyperspectral remote sensing technologies combined with machine learning provides a practical means for modelling vineyard water stress. In this study, we applied two ensemble learners, i.e., random forest (RF and extreme gradient boosting (XGBoost, for discriminating stressed and non-stressed Shiraz vines using terrestrial hyperspectral imaging. Additionally, we evaluated the utility of a spectral subset of wavebands, derived using RF mean decrease accuracy (MDA and XGBoost gain. Our results show that both ensemble learners can effectively analyse the hyperspectral data. When using all wavebands (p = 176, RF produced a test accuracy of 83.3% (KHAT (kappa analysis = 0.67, and XGBoost a test accuracy of 80.0% (KHAT = 0.6. Using the subset of wavebands (p = 18 produced slight increases in accuracy ranging from 1.7% to 5.5% for both RF and XGBoost. We further investigated the effect of smoothing the spectral data using the Savitzky-Golay filter. The results indicated that the Savitzky-Golay filter reduced model accuracies (ranging from 0.7% to 3.3%. The results demonstrate the feasibility of terrestrial hyperspectral imagery and machine learning to create a semi-automated framework for vineyard water stress modelling.

  8. Paraheliotropism can protect water-stressed bean (Phaseolus vulgaris L.) plants against photoinhibition.

    Science.gov (United States)

    Pastenes, Claudio; Porter, Victor; Baginsky, Cecilia; Horton, Peter; González, Javiera

    2004-12-01

    In order to estimate the importance of leaf movements on photosynthesis in well-watered and water-stressed field grown bean cultivars (Arroz Tuscola (AT), Orfeo INIA (OI), Bayos Titan (BT), and Hallados Dorado (HD)), CO2 assimilation, leaf temperature, and capacity for the maximum quantum yield recovery, measured as Fv/Fm, were assessed. Leaf water potential was lower in water-stressed compared to control plants throughout the day. Water status determined a decrease in the CO2 assimilation and stomatal conductance as light intensity and temperature increased up to maximal intensities at midday. Both parameters were lower in stressed compared to control plants. Even though high light intensity and water-stress induced stomatal closure is regarded as a photoinhibitory condition, the recovery of variable to maximal fluorescence (Fv/Fm) after 30min of darkness was nearly constant in both water regimes. In fact, higher values were observed in OI and AT when under stress. Photochemical and non-photochemical fluorescence quenching resulted in minor changes during the day and were similar between watered and stressed plants. It is concluded that paraheliotropism, present in the four bean cultivars, efficiently protects stressed plants from photoinhibition in the field and helps maintain leaf temperatures far below the ambient temperatures, however, it may also be responsible for low CO2 assimilation rates in watered plants.

  9. Physiological changes of pepper accessions in response to salinity and water stress

    International Nuclear Information System (INIS)

    López-Serrano, L.; Penella, C.; San Bautista, A.; López-Galarza, S.; Calatayud, A.

    2017-01-01

    New sources of water stress and salinity tolerances are needed for crops grown in marginal lands. Pepper is considered one of the most important crops in the world. Many varieties belong to the genus Capsicum spp., and display wide variability in tolerance/sensitivity terms in response to drought and salinity stress. The objective was to screen seven salt/drought-tolerant pepper accessions to breed new cultivars that could overcome abiotic stresses, or be used as new crops in land with water and salinity stress. Fast and effective physiological traits were measured to achieve the objective. The present study showed wide variability of the seven pepper accessions in response to both stresses. Photosynthesis, stomatal conductance and transpiration reduced mainly under salinity due to stomatal and non-stomatal (Na+ accumulation) constraints and, to a lesser extent, in the accessions grown under water stress. A positive relationship between CO2 fixation and fresh weight generation was observed for both stresses. Decreases in Ys and YW and increased proline were observed only when accessions were grown under salinity. However, these factors were not enough to alleviate salt effects and an inverse relation was noted between plant salt tolerance and proline accumulation. Under water stress, A31 was the least affected and A34 showed the best tolerance to salinity in terms of photosynthesis and biomass.

  10. Isolation and characterization of a water stress-specific genomic gene, pwsi 18, from rice.

    Science.gov (United States)

    Joshee, N; Kisaka, H; Kitagawa, Y

    1998-01-01

    One of the water stress-specific cDNA clones of rice characterised previously, wsi18, was selected for further study. The wsi18 gene can be induced by water stress conditions such as mannitol, NaCl, and dryness, but not by ABA, cold, or heat. A genomic clone for wsi18, pwsi18, contained about 1.7 kbp of the 5' upstream sequence, two introns, and the full coding sequence. The 5'-upstream sequence of pwsi18 contained putative cis-acting elements, namely an ABA-responsive element (ABRE), three G-boxes, three E-boxes, a MEF-2 sequence, four direct and two inverted repeats, and four sequences similar to DRE, which is involved in the dehydration response of Arabidopsis genes. The gusA reporter gene under the control of the pwsi18 promoter showed transient expression in response to water stress. Deletion of the downstream DRE-like sequence between the distal G-boxes-2 and -3 resulted in rather low GUS expression.

  11. Goodbye, Mandatory Maternity Leaves

    Science.gov (United States)

    Nation's Schools, 1972

    1972-01-01

    In precedent-setting decrees, courts and federal and State authorities have branded compulsory maternity leaves either unconstitutional or illegal. School administrators are urged to prod boards of education to adopt more lenient maternity leave policies -- now. (Author)

  12. Leaving home in Denmark

    DEFF Research Database (Denmark)

    Nielsen, Rikke Skovgaard

    2015-01-01

    The paper focuses on ethnic differences in the timing and patterns of leaving the parental home. Leaving home is a key transition in the life course of the individual, and extensive research has been conducted on the timing and patterns of leaving it. However, ethnic differences in these patterns...... of leaving home. Results showed that while some differences disappeared when controlling for covariates, others persisted, thus indicating ethnic differences in home-leaving patterns. A strong link between leaving home and marriage was substantiated for Turks, but not for Somalis. The home-leaving patterns...... of Somalis were much more similar to those of Danes. Overall, Turkish descendants were similar to Turkish immigrants but with some differentiation. The analyses identified the existence of ethnic differences in home-leaving patterns but also found evidence of a shift towards less traditional patterns, i...

  13. Induced mutations for disease resistance in wheat and barley

    International Nuclear Information System (INIS)

    Hanis, M.; Hanisova, A.; Knytl, V.; Cerny, J.; Benc, S.

    1977-01-01

    The induction of mutations in cultivars of wheat (Triticum aestivum), barley (Hordeum vulgare), and field beans (Phaseolus vulgaris) has been part of the breeding programme at the Plant Breeding Station at Stupice since 1960. A total of 26 cultivars or selections of winter wheat, 4 cultivars or selections of spring wheat, 2 cultivars of field beans, and 43 selections of spring barley have been treated since 1960. A total of 140 mutant lines of wheat and 37 mutant lines of barley with improved disease resistance of a race-specific type have been obtained. Several mutation programme derived cultivars have been registered in Czechoslovakia (''Diamant'', ''Ametyst'', ''Favorit'', ''Hana'', ''Rapid'', and ''Atlas'' in barley, and ''Alfa'' in field beans), but none of them is a mutation for disease resistance. A series of mutants have been used in crossing programmes. Approaches to improve the efficiency of mutation breeding for disease resistance are suggested. (author)

  14. Barley starch bioengineering for high phosphate and amylose

    DEFF Research Database (Denmark)

    Blennow, Per Gunnar Andreas; Carciofi, Massimiliano; Shaik, Shahnoor Sultana

    2011-01-01

    Starch is a biological polymer that can be industrially produced in massive amounts in a very pure form. Cereals is the main source for starch production and any improvement of the starch fraction can have a tremendous impact in food and feed applications. Barley ranks number four among cereal...... crops and barley is a genetically very well characterized. Aiming at producing new starch qualities in the cereal system, we used RNAi and overexpression strategies to produce pure amylose and high-phosphate starch, respectively, using the barley kernel as a polymer factory. By simultaneous silencing...... of the three genes encoding the starch-branching enzymes SBEI, SBEIIa, and SBEIIb using a triple RNAi chimeric hairpin construct we generated a virtually amylopectin-free barley. The grains of the transgenic lines were shrunken and had a yield of around 80% of the control line. The starch granules were...

  15. Application of proteomics to investigate barley-Fusarium graminearum interaction

    DEFF Research Database (Denmark)

    Yang, Fen

    in plants under low N and iv) proteomes of uninfected plants were similar under two N levels. Correlation of level of proteolysis induced by the fungus with measurement of Fusarium-damaged kernels, fungal biomass and mycotoxin levels indicated that FHB was more severe in barley with low N. In Chapter 3......, the molecular mechanisms of barley defense to Fusarium graminearum at the early infection stage were studied. Antibodies against barley β-amylases were shown to be the markers for infection at proteome level and for selection of the time for proteome analysis before extensive degradation caused by the fungus...... the disease. Due to the advantages of gel-based proteomics that differentially expressed proteins involved in the interaction can be directly detected by comparing protein profiles displayed on 2-D gels, it is used as a tool for studying the barley- Fusarium graminearum interaction form three different...

  16. Effects of irradiated barley on fattening quail (Coturnix coturnix japonica)

    International Nuclear Information System (INIS)

    Dahlhelm, H.

    1999-01-01

    For the feeding experiments reported, barley grains irradiated at doses of 2, 10, and 100 kGy were used as a diet. The results obtained revealed no significant effects in the parameters analysed. (orig./CB) [de

  17. Mapping of HKT1;5 Gene in Barley Using GWAS Approach and Its Implication in Salt Tolerance Mechanism

    Science.gov (United States)

    Hazzouri, Khaled M.; Khraiwesh, Basel; Amiri, Khaled M. A.; Pauli, Duke; Blake, Tom; Shahid, Mohammad; Mullath, Sangeeta K.; Nelson, David; Mansour, Alain L.; Salehi-Ashtiani, Kourosh; Purugganan, Michael; Masmoudi, Khaled

    2018-01-01

    Sodium (Na+) accumulation in the cytosol will result in ion homeostasis imbalance and toxicity of transpiring leaves. Studies of salinity tolerance in the diploid wheat ancestor Triticum monococcum showed that HKT1;5-like gene was a major gene in the QTL for salt tolerance, named Nax2. In the present study, we were interested in investigating the molecular mechanisms underpinning the role of the HKT1;5 gene in salt tolerance in barley (Hordeum vulgare). A USDA mini-core collection of 2,671 barley lines, part of a field trial was screened for salinity tolerance, and a Genome Wide Association Study (GWAS) was performed. Our results showed important SNPs that are correlated with salt tolerance that mapped to a region where HKT1;5 ion transporter located on chromosome four. Furthermore, sodium (Na+) and potassium (K+) content analysis revealed that tolerant lines accumulate more sodium in roots and leaf sheaths, than in the sensitive ones. In contrast, sodium concentration was reduced in leaf blades of the tolerant lines under salt stress. In the absence of NaCl, the concentration of Na+ and K+ were the same in the roots, leaf sheaths and leaf blades between the tolerant and the sensitive lines. In order to study the molecular mechanism behind that, alleles of the HKT1;5 gene from five tolerant and five sensitive barley lines were cloned and sequenced. Sequence analysis did not show the presence of any polymorphism that distinguishes between the tolerant and sensitive alleles. Our real-time RT-PCR experiments, showed that the expression of HKT1;5 gene in roots of the tolerant line was significantly induced after challenging the plants with salt stress. In contrast, in leaf sheaths the expression was decreased after salt treatment. In sensitive lines, there was no difference in the expression of HKT1;5 gene in leaf sheath under control and saline conditions, while a slight increase in the expression was observed in roots after salt treatment. These results provide

  18. Mapping of HKT1;5 Gene in Barley Using GWAS Approach and Its Implication in Salt Tolerance Mechanism

    Directory of Open Access Journals (Sweden)

    Khaled M. Hazzouri

    2018-02-01

    Full Text Available Sodium (Na+ accumulation in the cytosol will result in ion homeostasis imbalance and toxicity of transpiring leaves. Studies of salinity tolerance in the diploid wheat ancestor Triticum monococcum showed that HKT1;5-like gene was a major gene in the QTL for salt tolerance, named Nax2. In the present study, we were interested in investigating the molecular mechanisms underpinning the role of the HKT1;5 gene in salt tolerance in barley (Hordeum vulgare. A USDA mini-core collection of 2,671 barley lines, part of a field trial was screened for salinity tolerance, and a Genome Wide Association Study (GWAS was performed. Our results showed important SNPs that are correlated with salt tolerance that mapped to a region where HKT1;5 ion transporter located on chromosome four. Furthermore, sodium (Na+ and potassium (K+ content analysis revealed that tolerant lines accumulate more sodium in roots and leaf sheaths, than in the sensitive ones. In contrast, sodium concentration was reduced in leaf blades of the tolerant lines under salt stress. In the absence of NaCl, the concentration of Na+ and K+ were the same in the roots, leaf sheaths and leaf blades between the tolerant and the sensitive lines. In order to study the molecular mechanism behind that, alleles of the HKT1;5 gene from five tolerant and five sensitive barley lines were cloned and sequenced. Sequence analysis did not show the presence of any polymorphism that distinguishes between the tolerant and sensitive alleles. Our real-time RT-PCR experiments, showed that the expression of HKT1;5 gene in roots of the tolerant line was significantly induced after challenging the plants with salt stress. In contrast, in leaf sheaths the expression was decreased after salt treatment. In sensitive lines, there was no difference in the expression of HKT1;5 gene in leaf sheath under control and saline conditions, while a slight increase in the expression was observed in roots after salt treatment. These

  19. Serine:glyoxylate aminotransferase mutant of barley

    International Nuclear Information System (INIS)

    Blackwell, R.; Murray, A.; Joy, K.; Lea, P.

    1987-01-01

    A photorespiratory mutant of barley (LaPr 85/84), deficient in both of the major peaks of serine:glyoxylate aminotransferase activity detected in the wild type, also lacks serine:pyruvate and asparagine:glyoxylate aminotransferase activities. Genetic analysis of the mutation demonstrated that these three activities are all carried on the same enzyme. The mutant, when placed in air, accumulated a large pool of serine, showed the expected rate (50%) of ammonia release during photorespiration but produced CO 2 at twice the wild type rate when it was fed [ 14 C] glyoxylate. Compared with the wild type, LaPr 85/84 exhibited abnormal transient changes in chlorophyll a fluorescence when the CO 2 concentration of the air was altered, indicating that the rates of the fluorescence quenching mechanisms were affected in vivo by the lack of this enzyme

  20. The spontaneous chlorophyll mutation frequency in barley

    DEFF Research Database (Denmark)

    Jørgensen, Jørgen Helms; Jensen, Hans Peter

    1986-01-01

    A total of 1866 barley plants were progeny tested in the greenhouse. Twenty-five plants segregated for newly arisen, spontaneous chlorophyll mutant genes. Among the total of 470,129 seedlings screened there were 79 mutants (1.7 .+-. 0.6 .times. 10-4). The data are added to data from three similar...... materials and the resulting estimate of the chlorophyll mutant frequency is 1.6 .times. 10-4 in about 1.43 million seedlings. The estimate of the chlorophyll mutation rate per generation is close to 67.3 .times. 10-4 per diploid genome or in the order of 6 .times. 10-7 per locus and haploid genome....

  1. The Localization of Eceriferum Loci in Barley

    DEFF Research Database (Denmark)

    Søgaard, Bodil

    1974-01-01

    Three different 3-point tests have been made for gene distances on chromosome 1 in barley (Hordeum vulgare L.). In all cases eceriferum, cer-f9, and albina, ac2, were examined with erectoides as the third gene. The erectoides, ert, genes are ert-a23, ert-d33 and ert-m40, respectively. The analyses...... have been carried through to F3. The experiments demonstrated the following sequence of the five genes: cer-f9 — ac2 — ert-d33 — ert-a23 — ert-m40 and the following distances: cer-f9 — ac2 = 2.3 %, ac2 — ert-a23 = 8.5 %, ac2 — ert-d33 = 2.5 % and ac2 — ert-m40 = 12.8 %. The cer-f9 — ac2 distance, which...

  2. Cisgenic barley with improved phytase activity

    DEFF Research Database (Denmark)

    Holme, Inger; Dionisio, Giuseppe; Brinch-Pedersen, Henrik

    2012-01-01

    phytase gene (HvPAPhy_a) expressed during grain filling to evaluate the cisgenesis concept in barley. The marker gene elimination method was used to obtain marker-free plant lines. Here, the gene of interest and the selection gene are flanked by their own T-DNA borders to allow unlinked integration...... of the two genes. We analysed the transformants for co-transformation efficiency, increased phytase activities in the grain, integration of the kanamycin resistance gene of the vector-backbone and segregation between the HvPAPhy_a insert and the hygromycin resistance gene. The frequencies of the four......PAPhy_a insert for further analysis. Seeds from plants homozygous for the insert showed 2.6- and 2.8-fold increases in phytase activities and the activity levels were stable over the three generations analysed. In one of the selected lines, the flanking sequences from both the left and right T-DNA borders were...

  3. Cisgenic Barley with Improved Phytase Activity

    DEFF Research Database (Denmark)

    Holme, Inger; Dionisio, Giuseppe; Brinch-Pedersen, Henrik

    2010-01-01

    barley lambda library has been used to isolate the genomic clone of this phytase including 2.3 kb of the promoter region and 600 bp of the terminator region. The clone has been inserted into a cisgenic Agrobacterium vector where both the gene of interest and the selection gene are flanked by their own T......-DNA borders in order to promote integration of the two genes at unlinked places in the plant genome. Transformed T0 plants show increases in the phytase activity of mature seeds from 1,400 in wild type to 8,950 FTU/kg in T0 plants. T1 plants of each transformant are currently screened with PCR for extra...... copies of the genomic phytase gene and the selection gene to identify segregation between the two genes. Presently, we have identified two cisgenic T1 plants without vector backbone and selection gene but with an extra copy of the genomic phytase gene....

  4. Cisgenic barley with improved phytase activity

    DEFF Research Database (Denmark)

    Holme, Inger; Dionisio, Giuseppe; Brinch-Pedersen, Henrik

    2010-01-01

    barley lambda library has been used to isolate the genomic clone of this phytase including 2.3 kb of the promoter region and 600 bp of the terminator region. The clone has been inserted into a cisgenic Agrobacterium vector where both the gene of interest and the selection gene are flanked by their own T......-DNA borders in order to promote integration of the two genes at unlinked places in the plant genome. Transformed T0 plants show increases in the phytase activity of mature seeds from 1,400 in wild type to 8,950 FTU/kg in T0 plants. T1 plants of each transformant are currently screened with PCR for extra...... copies of the genomic phytase gene and the selection gene to identify segregation between the two genes. Presently, we have identified two cisgenic T1 plants without vector backbone and selection gene but with an extra copy of the genomic phytase gene....

  5. Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

    Science.gov (United States)

    Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

    2014-01-01

    Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

  6. Application of proteomics to investigate barley-Fusarium graminearum interaction

    OpenAIRE

    Yang, Fen; Finnie, Christine; Jacobsen, Susanne

    2011-01-01

    Due to the great loss of barley grain yield and quality in addition to mycotoxins contamination caused by Fusarium head blight (FHB), it is essential to understand the molecular interaction between barley and Fusarium graminearum, one of the primary Fusarium species causing FHB, in order to control the disease. Due to the advantages of gel-based proteomics that differentially expressed proteins involved in the interaction can be directly detected by comparing protein profiles displayed on 2-D...

  7. Serine/threonine phosphatase tapp2cs might be served as an early signal molecule for water stress in wheat

    International Nuclear Information System (INIS)

    Song, K. H.; Tian, W. L.; Hou, B. Z.; Guo, J. X.; Mei, X. R.; Li, Y. Z.

    2015-01-01

    Much progress has been made towards understanding the role of serine/threonine phosphatases type 2C (PP2Cs) in abscisic acid (ABA) signaling transduction. However, how the negative regulator, PP2Cs, responds to plant water loss remains unclear. Here, we used a series of relative soil moisture (RSM: 85 percentage (well watered), 65 percentage (moderate stress), 45 percentage (severe stress) potted winter wheat (Triticum aestivum L.) and the detached leaves to detect ABA levels and transcripts of PP2Cs, including PP2C40, PP2C45, PP2C59 and PP2C6 as well as the core downstream signals of ABA, including ABF, SnRK2.4 and SnRK2.5. The results showed that the continual loss of water led to a consistent increase in ABA levels, and that the mRNA expression levels of PP2Cs were dependent on plant water condition. PP2Cs expression could be induced by a slight loss of water, and inhibited under severe loss of water. These results were further confirmed by the transcripts of ABF, SnRK2.4 and SnRK2.5. Furthermore, in slight loss of water, 100 μM exogenous ABA could promote PP2Cs expression; in severe loss of water, it inhibited PP2Cs expression. In conclusion, ABA accumulation is controlled by water condition and the PP2C expression is dependent on plant water condition, suggesting that PP2Cs might be served as an early signal molecule for water stress in wheat. (author)

  8. Effect of maltose and trehalose on growth, yield and some biochemical components of wheat plant under water stress

    Directory of Open Access Journals (Sweden)

    Hemmat A. Ibrahim

    2016-12-01

    Full Text Available In the greenhouse experiment, wheat plants (Triticum aestivum L. cv. Giza 168 were treated with 10 mM of maltose and trehalose as foliar spray using Tween 20 as wetting agent at 15, 30 and 45 days post sowing with two times of irrigation at 10 and 20 days intervals. Two samples were taken after 45 and 120 days from planting. At the first sample date, plant height, shoot fresh and dry weights and leaf area were recorded. At harvesting time (the second sample no. of spikes/plant, no. of spikelets/plant and weight of 1000 grains were taken. Chemical analyses were conducted in leaves at the first sample date for determination of phenolic compounds, flavonoids, amino acids, reducing sugars, total soluble sugars, protein, proline, PAL, POD, ascorbate peroxidase, catalase, PPO and MDA. The obtained results indicated that maltose and trehalose had significant and positive effect on most growth parameters. Opposite trend was found in plant height, no. of spike/plant and weight of 1000 grains by drought treatment. Maltose and trehalose treatments enhanced in the most biochemical components whereas they decreased PAL and catalase activity. Variable trends in amino acids and ascorbate peroxidase were observed by drought. However, the drought has more stimulative effect in most cases than the first time period of irrigation. The results concluded that foliar applications with maltose or trehalose induced water stress tolerance in wheat plants. Maltose treatment gave the best results in most morphological parameters, grains yield and biochemical components than trehalose treatment.

  9. Bread wheat progenitors: Aegilops tauschii (DD genome) and Triticum dicoccoides (AABB genome) reveal differential antioxidative response under water stress.

    Science.gov (United States)

    Suneja, Yadhu; Gupta, Anil Kumar; Bains, Navtej Singh

    2017-01-01

    -genomes into a synthetic hexaploid for improving wheat for water stress conditions.

  10. The wheat resistance gene Lr34 results in the constitutive induction of multiple defense pathways in transgenic barley.

    Science.gov (United States)

    Chauhan, Harsh; Boni, Rainer; Bucher, Rahel; Kuhn, Benjamin; Buchmann, Gabriele; Sucher, Justine; Selter, Liselotte L; Hensel, Goetz; Kumlehn, Jochen; Bigler, Laurent; Glauser, Gaëtan; Wicker, Thomas; Krattinger, Simon G; Keller, Beat

    2015-10-01

    The wheat gene Lr34 encodes an ABCG-type transporter which provides durable resistance against multiple pathogens. Lr34 is functional as a transgene in barley, but its mode of action has remained largely unknown both in wheat and barley. Here we studied gene expression in uninfected barley lines transgenic for Lr34. Genes from multiple defense pathways contributing to basal and inducible disease resistance were constitutively active in seedlings and mature leaves. In addition, the hormones jasmonic acid and salicylic acid were induced to high levels, and increased levels of lignin as well as hordatines were observed. These results demonstrate a strong, constitutive re-programming of metabolism by Lr34. The resistant Lr34 allele (Lr34res) encodes a protein that differs by two amino acid polymorphisms from the susceptible Lr34sus allele. The deletion of a single phenylalanine residue in Lr34sus was sufficient to induce the characteristic Lr34-based responses. Combination of Lr34res and Lr34sus in the same plant resulted in a reduction of Lr34res expression by 8- to 20-fold when the low-expressing Lr34res line BG8 was used as a parent. Crosses with the high-expressing Lr34res line BG9 resulted in an increase of Lr34sus expression by 13- to 16-fold in progenies that inherited both alleles. These results indicate an interaction of the two Lr34 alleles on the transcriptional level. Reduction of Lr34res expression in BG8 crosses reduced the negative pleiotropic effects of Lr34res on barley growth and vigor without compromising disease resistance, suggesting that transgenic combination of Lr34res and Lr34sus can result in agronomically useful resistance. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  11. Assessing the ratio of leaf carbon to nitrogen in winter wheat and spring barley based on hyperspectral data

    Science.gov (United States)

    Xu, Xin-gang; Gu, Xiao-he; Song, Xiao-yu; Xu, Bo; Yu, Hai-yang; Yang, Gui-jun; Feng, Hai-kuan

    2016-10-01

    The metabolic status of carbon (C) and nitrogen (N) as two essential elements of crop plants has significant influence on the ultimate formation of yield and quality in crop production. The ratio of carbon to nitrogen (C/N) from crop leaves, defined as ratio of LCC (leaf carbon concentration) to LNC (leaf nitrogen concentration), is an important index that can be used to diagnose the balance between carbon and nitrogen, nutrient status, growth vigor and disease resistance in crop plants. Thus, it is very significant for effectively evaluating crop growth in field to monitor changes of leaf C/N quickly and accurately. In this study, some typical indices aimed at N estimation and chlorophyll evaluation were tested to assess leaf C/N in winter wheat and spring barley. The multi-temporal hyperspectral measurements from the flag-leaf, anthesis, filling, and milk-ripe stages were used to extract these selected spectral indices to estimate leaf C/N in wheat and barley. The analyses showed that some tested indices such as MTCI, MCARI/OSAVI2, and R-M had the better performance of assessing C/N for both of crops. Besides, a mathematic algorithm, Branch-and-Bound (BB) method was coupled with the spectral indices to assess leaf C/N in wheat and barley, and yielded the R2 values of 0.795 for winter wheat, R2 of 0.727 for spring barley, 0.788 for both crops combined. It demonstrates that using hyperspectral data has a good potential for remote assessment of leaf C/N in crops.

  12. Development of endosperm transfer cells in barley.

    Science.gov (United States)

    Thiel, Johannes

    2014-01-01

    Endosperm transfer cells (ETCs) are positioned at the intersection of maternal and filial tissues in seeds of cereals and represent a bottleneck for apoplasmic transport of assimilates into the endosperm. Endosperm cellularization starts at the maternal-filial boundary and generates the highly specialized ETCs. During differentiation barley ETCs develop characteristic flange-like wall ingrowths to facilitate effective nutrient transfer. A comprehensive morphological analysis depicted distinct developmental time points in establishment of transfer cell (TC) morphology and revealed intracellular changes possibly associated with cell wall metabolism. Embedded inside the grain, ETCs are barely accessible by manual preparation. To get tissue-specific information about ETC specification and differentiation, laser microdissection (LM)-based methods were used for transcript and metabolite profiling. Transcriptome analysis of ETCs at different developmental stages by microarrays indicated activated gene expression programs related to control of cell proliferation and cell shape, cell wall and carbohydrate metabolism reflecting the morphological changes during early ETC development. Transporter genes reveal distinct expression patterns suggesting a switch from active to passive modes of nutrient uptake with the onset of grain filling. Tissue-specific RNA-seq of the differentiating ETC region from the syncytial stage until functionality in nutrient transfer identified a high number of novel transcripts putatively involved in ETC differentiation. An essential role for two-component signaling (TCS) pathways in ETC development of barley emerged from this analysis. Correlative data provide evidence for abscisic acid and ethylene influences on ETC differentiation and hint at a crosstalk between hormone signal transduction and TCS phosphorelays. Collectively, the data expose a comprehensive view on ETC development, associated pathways and identified candidate genes for ETC

  13. High-throughput Agrobacterium-mediated barley transformation

    Directory of Open Access Journals (Sweden)

    Snape John W

    2008-09-01

    Full Text Available Abstract Background Plant transformation is an invaluable tool for basic plant research, as well as a useful technique for the direct improvement of commercial crops. Barley (Hordeum vulgare is the fourth most abundant cereal crop in the world. It also provides a useful model for the study of wheat, which has a larger and more complex genome. Most existing barley transformation methodologies are either complex or have low ( Results A robust, simple and reproducible barley transformation protocol has been developed that yields average transformation efficiencies of 25%. This protocol is based on the infection of immature barley embryos with Agrobacterium strain AGL1, carrying vectors from the pBract series that contain the hpt gene (conferring hygromycin resistance as a selectable marker. Results of large scale experiments utilising the luc (firefly luciferase gene as a reporter are described. The method presented here has been used to produce hundreds of independent, transgenic plant lines and we show that a large proportion of these lines contain single copies of the luc gene. Conclusion This protocol demonstrates significant improvements in both efficiency and ease of use over existing barley transformation methods. This opens up opportunities for the development of functional genomics resources in barley.

  14. Stimulation of bacteria and protists in rhizosphere of glyphosate-treated barley

    DEFF Research Database (Denmark)

    Imparato, Valentina; Santos, Susana; Johansen, Anders

    2016-01-01

    and protist communities to foliar application of glyphosate, we measured bacterial and protist abundance, diversity and physiological status, as well as soil organic carbon. Foliar application of glyphosate doubled bacterial abundance of the culturable fraction present in the rhizosphere compared to the other...... treatments with no effect on total abundance. Also the abundance of culturable protists increased as an effect of glyphosate and the bacterial genetic diversity as revealed by 16S rDNA DGGE analysis was affected. Overall, the results indicate that when barley leaves are treated with glyphosate......, the availability of organic carbon in the rhizosphere of the dying roots is altered, which in turn may alter the bacterial and protist communities and their interactions. This can have implications for general soil carbon turnover processes and CO2 release in arable systems....

  15. Changes in the Levels of Abscisic Acid and Its Metabolites in Excised Leaf Blades of Xanthium strumarium during and after Water Stress 1

    Science.gov (United States)

    Zeevaart, Jan A. D.

    1980-01-01

    The time course of abscisic acid (ABA) accumulation during water stress and of degradation following rehydration was investigated by analyzing the levels of ABA and its metabolites phaseic acid (PA) and alkalihydrolyzable conjugated ABA in excised leaf blades of Xanthium strumarium. Initial purification was by reverse-phase, preparative, high performance liquid chromatography (HPLC) which did not require prior partitioning. ABA and PA were purified further by analytical HPLC with a μBondapak-NH2 column, and quantified by GLC with an electron capture detector. The ABA content of stressed leaves increased for 4 to 5 hours and then leveled off due to a balance between synthesis and degradation. Since PA accumulated at a constant rate throughout the wilting period, it was concluded that the rate of ABA synthesis decreased after the first 4 to 5 hours stress. Conjugated ABA increased at a low rate during stress. This is interpreted to indicate that free ABA was converted to the conjugated form, rather than the reverse. Following rehydration of wilted leaves, the ABA level immediately ceased increasing; it remained constant for 1 hour and then declined rapidly to the prestress level over a 2- to 3-hour period with a concomitant rise in the PA level. In contrast to the rapid disappearance of ABA after relief of stress, the high PA content of rehydrated leaves declined only slowly. The level of conjugated ABA did not change following rehydration, indicating that conjugation of ABA was irreversible. Detached Xanthium leaves that were subjected to a wilting-recovery-rewilting cycle in darkness, responded to the second wilting period by formation of the same amount of ABA as accumulated after the first stress period. PMID:16661500

  16. Changes in the Levels of Abscisic Acid and Its Metabolites in Excised Leaf Blades of Xanthium strumarium during and after Water Stress.

    Science.gov (United States)

    Zeevaart, J A

    1980-10-01

    The time course of abscisic acid (ABA) accumulation during water stress and of degradation following rehydration was investigated by analyzing the levels of ABA and its metabolites phaseic acid (PA) and alkalihydrolyzable conjugated ABA in excised leaf blades of Xanthium strumarium. Initial purification was by reverse-phase, preparative, high performance liquid chromatography (HPLC) which did not require prior partitioning. ABA and PA were purified further by analytical HPLC with a muBondapak-NH(2) column, and quantified by GLC with an electron capture detector.The ABA content of stressed leaves increased for 4 to 5 hours and then leveled off due to a balance between synthesis and degradation. Since PA accumulated at a constant rate throughout the wilting period, it was concluded that the rate of ABA synthesis decreased after the first 4 to 5 hours stress. Conjugated ABA increased at a low rate during stress. This is interpreted to indicate that free ABA was converted to the conjugated form, rather than the reverse.Following rehydration of wilted leaves, the ABA level immediately ceased increasing; it remained constant for 1 hour and then declined rapidly to the prestress level over a 2- to 3-hour period with a concomitant rise in the PA level. In contrast to the rapid disappearance of ABA after relief of stress, the high PA content of rehydrated leaves declined only slowly. The level of conjugated ABA did not change following rehydration, indicating that conjugation of ABA was irreversible.Detached Xanthium leaves that were subjected to a wilting-recovery-rewilting cycle in darkness, responded to the second wilting period by formation of the same amount of ABA as accumulated after the first stress period.

  17. Nematode assemblages in the rhizosphere of spring barley (Hordeum vulgare L.) depended on fertilisation and plant growth phase

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård

    2004-01-01

    rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley......rhizosphere; nitrogen and phosphorus fertilisation; nematode assemblages; plant parasites; barley...

  18. Displacement of carbon-14 labelled amino acids from leaves

    International Nuclear Information System (INIS)

    Schiller, R.

    1973-01-01

    The displacement of amino acids from nature leaves was investigated. The amino acids (Ala, Asn, Asp, Glu, Gln, Val, Leu, Lys, Ser, Pro) were applied on the leaves in L-form, uniformly labelled with 14 C, and the type and direction of displacement have been observed. Most of the studies have been carried out on bush beans aged 3 to 4 weeks. The experiments were carried out in climatic chambers; in one case, barley plants just reaching maturity were used. In order to find out whether the applied amino acids were also displaced in their original form, freeze-dried plants were extracted and the 14 C activity of the various fraction was determined. The radioactivity of some free amino acids was determined after two-dimensional separation by thin film chromatography. (orig./HK) [de

  19. Abscisic acid biosynthesis in leaves and roots of Xanthium strumarium

    International Nuclear Information System (INIS)

    Creelman, R.A.; Gage, D.A.; Stults, J.T.; Zeevaart, J.A.D.

    1987-01-01

    Research on the biosynthesis of abscisic acid (ABA) has focused primarily on two pathways: (a) the direct pathway from farnesyl pyrophosphate, and (b) the indirect pathway involving a carotenoid precursor. The authors have investigated which biosynthetic pathway is operating in turgid and stressed Xanthium leaves, and in stressed Xanthium roots using long-term incubations in 18 O 2 . It was found that in stressed leaves three atoms of 18 O from 18 O 2 are incorporated into the ABA molecule, and that the amount of 18 O incorporated increases with time. One 18 O atom is incorporated rapidly into the carboxyl group of ABA, whereas the other two atoms are very slowly incorporated into the ring oxygens. The fourth oxygen atom in the carboxyl group of ABA is derived from water. ABA from stressed roots of Xanthium incubated in 18 O 2 shows a labeling pattern similar to that of ABA in stressed leaves, but with incorporation of more 18 O into the tertiary hydroxyl group at C-1' after 6 and 12 hours than found in ABA from stressed leaves. It is proposed that the precursors to stress-induced ABA are xanthophylls, and that a xanthophyll lacking an oxygen function at C-6 plays a crucial role in ABA biosynthesis in Xanthium roots. In turgid Xanthium leaves, 18 O is incorporated into ABA to a much lesser extent that it is in stressed leaves, whereas exogenously applied 14 C-ABA is completely catabolized within 48 hours. This suggests that ABA in turgid leaves is either (a) made via a biosynthetic pathway which is different from the one in stressed leaves, or (b) has a half-life on the order of days as compared with a half-life of 15.5 hours in water-stressed Xanthium leaves. Phaseic acid showed a labeling pattern similar to that of ABA, but with an additional 18 O incorporated during 8'-hydroxylation of ABA to phaseic acid

  20. Abscisic Acid Biosynthesis in Leaves and Roots of Xanthium strumarium.

    Science.gov (United States)

    Creelman, R A; Gage, D A; Stults, J T; Zeevaart, J A

    1987-11-01

    RESEARCH ON THE BIOSYNTHESIS OF ABSCISIC ACID (ABA) HAS FOCUSED PRIMARILY ON TWO PATHWAYS: (a) the direct pathway from farnesyl pyrophosphate, and (b) the indirect pathway involving a carotenoid precursor. We have investigated which biosynthetic pathway is operating in turgid and stressed Xanthium leaves, and in stressed Xanthium roots using long-term incubations in (18)O(2). It was found that in stressed leaves three atoms of (18)O from (18)O(2) are incorporated into the ABA molecule, and that the amount of (18)O incorporated increases with time. One (18)O atom is incorporated rapidly into the carboxyl group of ABA, whereas the other two atoms are very slowly incorporated into the ring oxygens. The fourth oxygen atom in the carboxyl group of ABA is derived from water. ABA from stressed roots of Xanthium incubated in (18)O(2) shows a labeling pattern similar to that of ABA in stressed leaves, but with incorporation of more (18)O into the tertiary hydroxyl group at C-1' after 6 and 12 hours than found in ABA from stressed leaves. It is proposed that the precursors to stress-induced ABA are xanthophylls, and that a xanthophyll lacking an oxygen function at C-6 (carotenoid numbering scheme) plays a crucial role in ABA biosynthesis in Xanthium roots. In turgid Xanthium leaves, (18)O is incorporated into ABA to a much lesser extent than it is in stressed leaves, whereas exogenously applied (14)C-ABA is completely catabolized within 48 hours. This suggests that ABA in turgid leaves is either (a) made via a biosynthetic pathway which is different from the one in stressed leaves, or (b) has a half-life on the order of days as compared with a half-life of 15.5 hours in water-stressed Xanthium leaves. Phaseic acid showed a labeling pattern similar to that of ABA, but with an additional (18)O incorporated during 8'-hydroxylation of ABA to phaseic acid.

  1. Water relations and gas exchange in poplar and willow under water stress and elevated atmospheric CO2.

    Science.gov (United States)

    Johnson, Jon D; Tognetti, Roberto; Paris, Piero

    2002-05-01

    Predictions of shifts in rainfall patterns as atmospheric [CO2] increases could impact the growth of fast growing trees such as Populus spp. and Salix spp. and the interaction between elevated CO2 and water stress in these species is unknown. The objectives of this study were to characterize the responses to elevated CO2 and water stress in these two species, and to determine if elevated CO2 mitigated drought stress effects. Gas exchange, water potential components, whole plant transpiration and growth response to soil drying and recovery were assessed in hybrid poplar (clone 53-246) and willow (Salix sagitta) rooted cuttings growing in either ambient (350 &mgr;mol mol-1) or elevated (700 &mgr;mol mol-1) atmospheric CO2 concentration ([CO2]). Predawn water potential decreased with increasing water stress while midday water potentials remained unchanged (isohydric response). Turgor potentials at both predawn and midday increased in elevated [CO2], indicative of osmotic adjustment. Gas exchange was reduced by water stress while elevated [CO2] increased photosynthetic rates, reduced leaf conductance and nearly doubled instantaneous transpiration efficiency in both species. Dark respiration decreased in elevated [CO2] and water stress reduced Rd in the trees growing in ambient [CO2]. Willow had 56% lower whole plant hydraulic conductivity than poplar, and showed a 14% increase in elevated [CO2] while poplar was unresponsive. The physiological responses exhibited by poplar and willow to elevated [CO2] and water stress, singly, suggest that these species respond like other tree species. The interaction of [CO2] and water stress suggests that elevated [CO2] did mitigate the effects of water stress in willow, but not in poplar.

  2. Physiological Responses of Bambara Groundnut (Vigna subterranea L. Verdc) to Short Periods of Water Stress During Different Developmental Stages

    OpenAIRE

    R. Vurayai; V. Emongor and B. Moseki

    2011-01-01

    The study was conducted to evaluate the responses of bambara groundnut (Vigna subterranea L. Verdc) to short periods of water stress imposed at different growth stages, and the recuperative ability of the species from drought stress. A major problem associated with Bambara groundnut production is its very low yields due to intra-seasonal and inter-seasonal variability in rainfall in semi-arid regions. The response pattern of physiological processes to water stress imposed at different growth ...

  3. Morphological plasticity of root growth under mild water stress increases water use efficiency without reducing yield in maize

    Science.gov (United States)

    Cai, Qian; Zhang, Yulong; Sun, Zhanxiang; Zheng, Jiaming; Bai, Wei; Zhang, Yue; Liu, Yang; Feng, Liangshan; Feng, Chen; Zhang, Zhe; Yang, Ning; Evers, Jochem B.; Zhang, Lizhen

    2017-08-01

    A large yield gap exists in rain-fed maize (Zea mays L.) production in semi-arid regions, mainly caused by frequent droughts halfway through the crop-growing period due to uneven distribution of rainfall. It is questionable whether irrigation systems are economically required in such a region since the total amount of rainfall does generally meet crop requirements. This study aimed to quantitatively determine the effects of water stress from jointing to grain filling on root and shoot growth and the consequences for maize grain yield, above- and below-ground dry matter, water uptake (WU) and water use efficiency (WUE). Pot experiments were conducted in 2014 and 2015 with a mobile rain shelter to achieve conditions of no, mild or severe water stress. Maize yield was not affected by mild water stress over 2 years, while severe stress reduced yield by 56 %. Both water stress levels decreased root biomass slightly but shoot biomass substantially. Mild water stress decreased root length but increased root diameter, resulting in no effect on root surface area. Due to the morphological plasticity in root growth and the increase in root / shoot ratio, WU under water stress was decreased, and overall WUE for both above-ground dry matter and grain yield increased. Our results demonstrate that an irrigation system might be not economically and ecologically necessary because the frequently occurring mild water stress did not reduce crop yield much. The study helps us to understand crop responses to water stress during a critical water-sensitive period (middle of the crop-growing season) and to mitigate drought risk in dry-land agriculture.

  4. Morphological plasticity of root growth under mild water stress increases water use efficiency without reducing yield in maize

    Directory of Open Access Journals (Sweden)

    Q. Cai

    2017-08-01

    Full Text Available A large yield gap exists in rain-fed maize (Zea mays L. production in semi-arid regions, mainly caused by frequent droughts halfway through the crop-growing period due to uneven distribution of rainfall. It is questionable whether irrigation systems are economically required in such a region since the total amount of rainfall does generally meet crop requirements. This study aimed to quantitatively determine the effects of water stress from jointing to grain filling on root and shoot growth and the consequences for maize grain yield, above- and below-ground dry matter, water uptake (WU and water use efficiency (WUE. Pot experiments were conducted in 2014 and 2015 with a mobile rain shelter to achieve conditions of no, mild or severe water stress. Maize yield was not affected by mild water stress over 2 years, while severe stress reduced yield by 56 %. Both water stress levels decreased root biomass slightly but shoot biomass substantially. Mild water stress decreased root length but increased root diameter, resulting in no effect on root surface area. Due to the morphological plasticity in root growth and the increase in root ∕ shoot ratio, WU under water stress was decreased, and overall WUE for both above-ground dry matter and grain yield increased. Our results demonstrate that an irrigation system might be not economically and ecologically necessary because the frequently occurring mild water stress did not reduce crop yield much. The study helps us to understand crop responses to water stress during a critical water-sensitive period (middle of the crop-growing season and to mitigate drought risk in dry-land agriculture.

  5. Water stress index for alkaline fen habitat based on UAV and continuous tower measurements of canopy infrared temperature

    Science.gov (United States)

    Ciężkowski, Wojciech; Jóźwiak, Jacek; Chormański, Jarosław; Szporak-Wasilewska, Sylwia; Kleniewska, Małgorzata

    2017-04-01

    This study is focused on developing water stress index for alkaline fen, to evaluate water stress impact on habitat protected within Natura 2000 network: alkaline fens (habitat code:7230). It is calculated based on continuous measurements of air temperature, relative humidity and canopy temperature from meteorological tower and several UAV flights for canopy temperature registration. Measurements were taken during the growing season in 2016 in the Upper Biebrza Basin in north-east Poland. Firstly methodology of the crop water stress index (CWSI) determination was used to obtained non-water stress base line based on continuous measurements (NWSBtower). Parameters of NWSBtower were directly used to calculate spatial variability of CWSI for UAV thermal infrared (TIR) images. Then for each UAV flight day at least 3 acquisition were performed to define NWSBUAV. NWSBUAV was used to calculate canopy waters stress for whole image relative to the less stressed areas. The spatial distribution of developed index was verified using remotely sensed indices of vegetation health. Results showed that in analysed area covered by sedge-moss vegetation NWSB cannot be used directly. The proposed modification of CWSI allows identifying water stress in alkaline fen habitats and was called as Sedge-Moss Water Stress Index (SMWSI). The study shows possibility of usage remotely sensed canopy temperature data to detect areas exposed to the water stress on wetlands. This research has been carried out under the Biostrateg Programme of the Polish National Centre for Research and Development (NCBiR), project No.: DZP/BIOSTRATEG-II/390/2015: The innovative approach supporting monitoring of non-forest Natura 2000 habitats, using remote sensing methods (HabitARS).

  6. Combined effects of water stress and pollution on macroinvertebrate and fish assemblages in a Mediterranean intermittent river.

    Science.gov (United States)

    Kalogianni, Eleni; Vourka, Aikaterini; Karaouzas, Ioannis; Vardakas, Leonidas; Laschou, Sofia; Skoulikidis, Nikolaos Th

    2017-12-15

    Water stress is a key stressor in Mediterranean intermittent rivers exacerbating the negative effects of other stressors, such as pollutants, with multiple effects on different river biota. The current study aimed to determine the response of macroinvertebrate and fish assemblages to instream habitat and water chemistry, at the microhabitat scale and at different levels of water stress and pollution, in an intermittent Mediterranean river. Sampling was conducted at high and low summer discharge, at two consecutive years, and included four reaches that were targeted for their different levels of water stress and pollution. Overall, the macroinvertebrate fauna of Evrotas River indicated high resilience to intermittency, however, variation in community structure and composition occurred under acute water stress, due to habitat alteration and change in water physico-chemistry, i.e. water temperature increase. The combined effects of pollution and high water stress had, however, pronounced effects on species richness, abundance and community structure in the pollution impacted reach, where pollution sensitive taxa were almost extirpated. Fish response to drought, in reaches free of pollution, consisted of an increase in the abundance of the two small limnophilic species, coupled with their shift to faster flowing riffle habitats, and a reduction in the abundance of the larger, rheophilic species. In the pollution impacted reach, however, the combination of pollution and high water stress led to hypoxic conditions assumed to be the leading cause of the almost complete elimination of the fish assemblage. In contrast, the perennial Evrotas reaches with relatively stable physicochemical conditions, though affected hydrologically by drought, appear to function as refugia for fish during high water stress. When comparing the response of the two biotic groups to combined acute water stress and pollution, it is evident that macroinvertebrates were negatively impacted, but fish

  7. Molecular response to water stress in two contrasting Mediterranean pines (Pinus pinaster and Pinus pinea).

    Science.gov (United States)

    Perdiguero, Pedro; Barbero, María Del Carmen; Cervera, María Teresa; Collada, Carmen; Soto, Alvaro

    2013-06-01

    Adaptation to water stress has determined the evolution and diversification of vascular plants. Water stress is forecasted to increase drastically in the next decades in certain regions, such as in the Mediterranean basin. Consequently, a proper knowledge of the response and adaptations to drought stress is essential for the correct management of plant genetic resources. However, most of the advances in the understanding of the molecular response to water stress have been attained in angiosperms, and are not always applicable to gymnosperms. In this work we analyse the transcriptional response of two emblematic Mediterranean pines, Pinus pinaster and Pinus pinea, which show noticeable differences in their performance under water stress. Using microarray analysis, up to 113 genes have been detected as significantly induced by drought in both species. Reliability of expression patterns has been confirmed by RT-PCR. While induced genes with similar profiles in both species can be considered as general candidate genes for the study of drought response in conifers, genes with diverging expression patterns can underpin the differences displayed by these species under water stress. Most promising candidate genes for drought stress response include genes related to carbohydrate metabolism, such as glycosyltransferases or galactosidases, sugar transporters, dehydrins and transcription factors. Additionally, differences in the molecular response to drought and polyethylene-glycol-induced water stress are also discussed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. Effects of different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower under water stress

    Directory of Open Access Journals (Sweden)

    Mostafa Heidari

    2014-01-01

    Full Text Available The role of arbuscular mycorrhizal fungi in alleviating water stress is well documented. In order to study the effects of water stress and two different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower, a field experiment as split plot design with three replications was conducted in the Research Field Station, Zabol University, Zabol, Iran in 2011. Water stress treatments included control as 90% of field capacity (W1, 70% field capacity (W2 and 50% field capacity (W3 assigned to the main plots and two different mycorrhiza species, consisting of M1 = control (without any inoculation, M2 = Glumus mossea and M3 = Glumus etanicatum as sub plots. Results showed that by increasing water stress from control (W1 to W3 treatment, grain yield was significantly decreased. The reduction in the level of W3 was 15.05%. The content of potassium in seeds significantly decreased due to water stress but water stress upto W2 treatment increased the content of phosphorus, nitrogen and oil content of seeds. In between two species of mycorrhiza in sunflower plants, Glumus etanicatum had the highest effect on grain yield and these elements in seeds and increased both.

  9. CO2 enrichment affects eco-physiological growth of maize and alfalfa under different water stress regimes in the UAE.

    Science.gov (United States)

    Ksiksi, Taoufik Saleh; Ppoyil, Shaijal Babu Thru; Palakkott, Abdul Rasheed

    2018-03-01

    Water stress has been reported to alter morphology and physiology of plants affecting chlorophyll content, stomatal size and density. In this study, drought stress mitigating effects of CO 2 enrichment was assessed in greenhouse conditions in the hot climate of UAE. Commercially purchased maize ( Zea mays L.) and alfalfa ( Medicago sativa L.) were seeded in three different custom-built cage structures, inside a greenhouse. One cage was kept at 1000 ppm CO 2 , the second at 700 ppm CO 2 , and the third at ambient greenhouse CO 2 environment (i.e. 435 ppm). Three water stress treatments HWS (200 ml per week), MWS (400 ml per week), and CWS (600 ml per week) were given to each cage so that five maize pots and five alfalfa pots in each cage received same water stress treatments. In maize, total chlorophyll content was similar or higher in water stress treatments compared to control for all CO 2 concentrations. Stomatal lengths were higher in enriched CO 2 environments under water stress. At 700 ppm CO 2 , stomatal widths decreased as water stress increased from MWS to HWS. At both enriched CO 2 environments, stomatal densities decreased compared to ambient CO 2 environment. In alfalfa, there was no significant increase in total chlorophyll content under enriched CO 2 environments, even though a slight increase was noticed.

  10. Bacteria-triggered systemic immunity in barley is associated with WRKY and ETHYLENE RESPONSIVE FACTORs but not with salicylic acid.

    Science.gov (United States)

    Dey, Sanjukta; Wenig, Marion; Langen, Gregor; Sharma, Sapna; Kugler, Karl G; Knappe, Claudia; Hause, Bettina; Bichlmeier, Marlies; Babaeizad, Valiollah; Imani, Jafargholi; Janzik, Ingar; Stempfl, Thomas; Hückelhoven, Ralph; Kogel, Karl-Heinz; Mayer, Klaus F X; Vlot, A Corina

    2014-12-01

    Leaf-to-leaf systemic immune signaling known as systemic acquired resistance is poorly understood in monocotyledonous plants. Here, we characterize systemic immunity in barley (Hordeum vulgare) triggered after primary leaf infection with either Pseudomonas syringae pathovar japonica (Psj) or Xanthomonas translucens pathovar cerealis (Xtc). Both pathogens induced resistance in systemic, uninfected leaves against a subsequent challenge infection with Xtc. In contrast to systemic acquired resistance in Arabidopsis (Arabidopsis thaliana), systemic immunity in barley was not associated with NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 or the local or systemic accumulation of salicylic acid. Instead, we documented a moderate local but not systemic induction of abscisic acid after infection of leaves with Psj. In contrast to salicylic acid or its functional analog benzothiadiazole, local applications of the jasmonic acid methyl ester or abscisic acid triggered systemic immunity to Xtc. RNA sequencing analysis of local and systemic transcript accumulation revealed unique gene expression changes in response to both Psj and Xtc and a clear separation of local from systemic responses. The systemic response appeared relatively modest, and quantitative reverse transcription-polymerase chain reaction associated systemic immunity with the local and systemic induction of two WRKY and two ETHYLENE RESPONSIVE FACTOR (ERF)-like transcription factors. Systemic immunity against Xtc was further associated with transcriptional changes after a secondary/systemic Xtc challenge infection; these changes were dependent on the primary treatment. Taken together, bacteria-induced systemic immunity in barley may be mediated in part by WRKY and ERF-like transcription factors, possibly facilitating transcriptional reprogramming to potentiate immunity. © 2014 American Society of Plant Biologists. All Rights Reserved.

  11. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

  12. Negative leave balances

    CERN Multimedia

    Human Resources Department

    2005-01-01

    Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

  13. Estimation of water content in the leaves of fruit trees using infra-red images

    International Nuclear Information System (INIS)

    Muramatsu, N.; Hiraoka, K.

    2006-01-01

    A method was developed to evaluate water contents of fruit trees using infra-red photography. The irrigation of potted satsuma mandarin trees and grapevines was suppressed to induce water stress. During the drought treatment the leaf edges of basal parts of the shoots of grapevines became necrotic and the area of necrosis extended as the duration of stress increased. Necrosis was clearly distinguished from the viable areas on infra-red images. In satsuma mandarin, an abscission layer formed at the basal part of the petiole, then the leaves fell. Thus, detailed analysis was indispensable for detecting of the leaf water content. After obtaining infra-red images of satsuma mandarin leaves with or without water stress, a background treatment (subtraction of the background image) was performed on the images, then the average brightness of the leaf was determined using image analyzing software (Image Pro-plus). Coefficient correlation between the water status index using the infra-red camera and water content determined from dry weight and fresh weight of leaves was significant (r = 0.917 for adaxial surface data and r = 0.880 for abaxial surface data). These data indicate that infra-red photography is useful for detecting the degree of plant water stress

  14. Molecular characterization of barley 3H semi-dwarf genes.

    Directory of Open Access Journals (Sweden)

    Haobing Li

    Full Text Available The barley chromosome 3H accommodates many semi-dwarfing genes. To characterize these genes, the two-rowed semi-dwarf Chinese barley landrace 'TX9425' was crossed with the Australian barley variety 'Franklin' to generate a doubled haploid (DH population, and major QTLs controlling plant height have been identified in our previous study. The major QTL derived from 'TX9425' was targeted to investigate the allelism of the semi-dwarf gene uzu in barley. Twelve sets of near-isogenic lines and a large NILF2 fine mapping population segregating only for the dwarfing gene from 'TX9425' were developed. The semi-dwarfing gene in 'TX9425' was located within a 2.8 cM region close to the centromere on chromosome 3H by fine mapping. Molecular cloning and sequence analyses showed that the 'TX9425'-derived allele contained a single nucleotide substitution from A to G at position 2612 of the HvBRI1 gene. This was apparently the same mutation as that reported in six-rowed uzu barley. Markers co-segregating with the QTL were developed from the sequence of the HvBRI1 gene and were validated in the 'TX9425'/'Franklin' DH population. The other major dwarfing QTL derived from the Franklin variety was distally located on chromosome 3HL and co-segregated with the sdw1 diagnostic marker hv20ox2. A third dwarfing gene, expressed only in winter-sown trials, was identified and located on chromosome 3HS. The effects and interactions of these dwarfing genes under different growing conditions are discussed. These results improve our understanding of the genetic mechanisms controlling semi-dwarf stature in barley and provide diagnostic markers for the selection of semi-dwarfness in barley breeding programs.

  15. Water stress as a trigger of demand change: exploring the implications for drought planning

    Science.gov (United States)

    Garcia, M. E.; Islam, S.; Portney, K. E.

    2015-12-01

    Drought in the Anthropocene is a function of both supply and demand. Despite its importance, demand is typically incorporated into planning models exogenously using a single scenario of demand change over time. Alternatively, demand is incorporated endogenously in hydro-economic models based on the assumption of rationality. However, actors are constrained by limited information and information processing capabilities, casting doubt on the rationality assumption. Though the risk of water shortage changes incrementally with demand growth and hydrologic change, significant shifts in management are punctuated and often linked to periods of stress. The observation of lasting decreases in per capita demands in a number of cities during periods of water stress prompts an alternate hypothesis: the occurrence of water stress increases the tendency of cities to promote and enforce efficient technologies and behaviors and the tendency of users to adopt them. We show the relevance of this hypothesis by building a model of a hypothetical surface water system to answer the following question: what is the impact of reservoir operation policy on the reliability of water supply for a growing city? The model links the rate of demand decreases to the past reliability to compare standard operating policy (SOP) with hedging policy (HP). Under SOP, demand is fulfilled unless available supply drops below demand; under HP, water releases are reduced in anticipation of a deficit to decrease the risk of a large shortfall. The model shows that reservoir storage acts both as a buffer for variability and as a delay triggering oscillations around a sustainable level of demand. HP reduces the threshold for action thereby decreasing the delay and the oscillation effect. As a result per capita demand decrease during periods of water stress are more frequent but less drastic and the additive effect of small adjustments decreases the tendency of the system to overshoot available supplies.

  16. Difference in canopy and air temperature as an indicator of grassland water stress

    International Nuclear Information System (INIS)

    Duffková, R.

    2006-01-01

    In 2003–2005 in conditions of the moderately warm region of the Třeboň Basin (Czech Republic) the difference between canopy temperature (T c ) and air temperature at 2 m (T a ) was tested as an indicator of grassland water stress. To evaluate water stress ten-minute averages of temperature difference T c –T a were chosen recorded on days without rainfall with intensive solar radiation from 11.00 to 14.00 CET. Water stress in the zone of the major portion of root biomass (0–0.2 m) in the peak growing season (minimum presence of dead plant residues) documented by a sudden increase in temperature difference, its value 5–12°C and unfavourable canopy temperatures due to overheating (> 30°C) was indicated after high values of suction pressure approaching the wilting point (1300 kPa) were reached. High variability of temperature difference in the conditions of sufficient supply of water to plants was explained by the amount of dead plant residues in canopy, value of vapour pressure deficit (VPD), actual evapotranspiration rate (ETA) and soil moisture content. At the beginning of the growing season (presence of dead plant residues and voids) we proved moderately strong negative linear correlations of T c –T a with VPD and T c –T a with ETA rate and moderately strong positive linear correlations of ETA rate with VPD. In the period of intensive growth (the coverage of dead plant residues and voids lower than 10%) moderately strong linear correlations of T c –T a with VPD and multiple linear correlations of T c –T a with VPD and soil moisture content at a depth of 0.10–0.40 m were demonstrated. (author)

  17. Sectoral contributions to surface water stress in the coterminous United States

    International Nuclear Information System (INIS)

    Averyt, K; Meldrum, J; Caldwell, P; Sun, G; McNulty, S; Huber-Lee, A; Madden, N

    2013-01-01

    Here, we assess current stress in the freshwater system based on the best available data in order to understand possible risks and vulnerabilities to regional water resources and the sectors dependent on freshwater. We present watershed-scale measures of surface water supply stress for the coterminous United States (US) using the water supply stress index (WaSSI) model which considers regional trends in both water supply and demand. A snapshot of contemporary annual water demand is compared against different water supply regimes, including current average supplies, current extreme-year supplies, and projected future average surface water flows under a changing climate. In addition, we investigate the contributions of different water demand sectors to current water stress. On average, water supplies are stressed, meaning that demands for water outstrip natural supplies in over 9% of the 2103 watersheds examined. These watersheds rely on reservoir storage, conveyance systems, and groundwater to meet current water demands. Overall, agriculture is the major demand-side driver of water stress in the US, whereas municipal stress is isolated to southern California. Water stress introduced by cooling water demands for power plants is punctuated across the US, indicating that a single power plant has the potential to stress water supplies at the watershed scale. On the supply side, watersheds in the western US are particularly sensitive to low flow events and projected long-term shifts in flow driven by climate change. The WaSSI results imply that not only are water resources in the southwest in particular at risk, but that there are also potential vulnerabilities to specific sectors, even in the ‘water-rich’ southeast. (letter)

  18. Solar-Induced Fluorescence of Maize Across A Water Stress Gradient in the Midwestern USA

    Science.gov (United States)

    Miao, G.; Guan, K.; Suyker, A.; Yang, X.; Benarcchi, C. J.; Gamon, J. A.; Berry, J. A.; DeLucia, E.; Franz, T.; Arkebauer, T. J.; Zygielbaum, A. I.; Walter-Shea, E. A.; Moore, C.; Zhang, Y.; Kim, H.; Hmimina, G.

    2017-12-01

    In the coming decades, agricultural ecosystems will be challenged by rising temperatures, changing rainfall patterns, and increasing extreme weather. Understanding how crops respond to weather variability and how humans manage agriculture to mitigate and adapt to climate change is critical for improving agricultural sustainability and supporting increasing global food demands. Accurately estimating gross primary productivity (GPP) of crops is of importance to evaluate their sustainability and capability but remains a challenge. The recent development of solar-induced fluorescence (SIF) technology is stimulating studies to use SIF to approximate GPP. It has been observed that agricultural lands have remarkably high SIF and the SIF signal could be used as an indicator of vegetation stress, which is particularly valuable for improved monitoring of crop productivity and stress. To investigate the applicability of SIF for detecting maize stress and estimating GPP, we deployed three FluoSpec2 systems in 2017 at three long-term eddy covariance flux sites across the US Corn Belt, a rain-fed maize field (AmeriFlux sites US-NE3) and an irrigated maize field (US-NE2) at Mead, Nebraska and a rain-fed maize field at Urbana, Illinois. Together these form a water stress gradient. Variations in GPP, SIF, photosynthetic efficiency (LUE), SIF yield (SIFy), and relationships between GPP and SIF, LUE and SIFy will be compared as indications of the difference in maize growth across the water stress gradient. More importantly, differences in GPP and SIF signals will be examined over multiple growth stages to assess the potential of SIF in identifying the growth stages that are mostly affected by water stress and the ones that play the most important roles on the crop yield.

  19. The influence of flooding on soil proportion and plant growth. 1. The influence on root development and growth of barley

    International Nuclear Information System (INIS)

    Sisworo, E.L.

    1975-01-01

    An experiment has been carried out to study the extent of root and shoot of barley exposed to flooding at various time of flooding. Several parameters were used in the experiment, namely the percentage of 86 Rb in the root system, dry weight of root as well as shoot, increase of leaf size, number of leaves and tillers and nitrogen content in leaf tissue. Radioactive 86 Rb-Cl was used in the experiment and injected into the plant 24 hours before harvest. The plants were harvested 2, 6, and 20 days after flooding. From the result obtained, it turned out that flooding conditions apparently reduced root development in the lower part of soil layer, while in the top layer a proper development of root was concentrated. Injury symptoms were mainly observed in the shoot; where leaf yellowing occured and started with the first leaf five days after flooding and subsequently reduced the number of leaves and tillers. (author)

  20. Effects of water stress on the root and shoot behaviour of rain-fed rice

    International Nuclear Information System (INIS)

    Bois, J.F.; Couchat, P.

    1983-01-01

    Application of the neutron technique to the roots of rain-fed rice seedlings during water stress has shown that there is a noticeable decrease in root diameter because of water loss and a slowing down of growth. At the leaf level the water deficiency results in modified gas exchanges due to closure of the stomata. Transpiration and photosynthesis appear to be independent of the soil-water potential above a threshold value in the neighbourhood of -600 mbar. Below this critical potential the closure of the stomata is progressive and proportional to the drop in water potential. (author)

  1. Evaluation of water stress and groundwater storage using a global hydrological model

    Science.gov (United States)

    Shiojiri, D.; Tanaka, K.; Tanaka, S.

    2017-12-01

    United Nations reported the number of people will reach 9.7 billion in 2050, and this rapid growth of population will increase water use. To prevent global water shortage, it is important to identify the problematic areas in order to maintain water resources sustainability. Moreover, groundwater availability is decreasing in some areas due to excessive groundwater extraction compared to the groundwater recharge capacity. The development of a hydrological model that can simulate the current status of the world's water resources represents an important tool to achieve sustainable water resources management. In this study, a global hydrological simulation is conducted at a 20km spatial resolution using the land surface model SiBUC, which is coupled to the river routing model HydroBEAM. In the river routing model, we evaluate water stress by comparing the excess of water demand with the river water demand. Areas with high water stress are seen in United States, India, and east part of China; however, for the case of Africa the overall water stress is zero. This could be because rain-fed agriculture is the norm in Africa and thus irrigation water demand is low, which affects water stress index. Sustainability of groundwater resources is also evaluated in the river routing model by setting a virtual groundwater tank. When the amount of groundwater withdrawal constantly exceeds groundwater recharge, the volume in the tank falls below zero and the area is regarded as unsustainable in terms of groundwater usage. Such areas are mostly seen in central United States, northeast China, the region between northwest India and Pakistan. In the simulation with SiBUC, the amount of groundwater recharge is assumed as the proportion of water that flows from the second to the third soil layer. This proportion will be estimated by comparing monthly variations of terrestrial water storage (TWS) derived from the observations of the GRACE satellite with the simulated TWS variations. From

  2. Proceedings: Primary water stress corrosion cracking: 1989 EPRI remedial measures workshop

    International Nuclear Information System (INIS)

    Gorman, J.A.

    1990-04-01

    A meeting on ''PWSCC Remedial Measures'' was organized to give those working in this area an opportunity to share their results, ideas and plans with regard to development and application of remedial measures directed against the primary water stress corrosion cracking (PWSCC) phenomenon affecting alloy 600 steam generator tubes. Topics discussed included: utility experience and strategies; nondestructive examination (NDE) methods for PWSCC; technical topics ranging from predictive methods for occurrence of PWSCC to results of corrosion tests; and services provided by vendors that can help prevent the occurrence of PWSCC or can help address problems caused by PWSCC once it occurs

  3. The Temporary Leave Dilemma -

    DEFF Research Database (Denmark)

    Amilon, Anna

    2010-01-01

    Lone mothers have to take care of a sick child with little or no help from the child’s other parent and have to carry all costs connected to leave-taking. This paper empirically tests whether lone mothers take more temporary parental leave to care for sick children than partnered mothers...... and whether parental leave is associated with a signaling cost. The results from this study of Swedish mothers show that lone mothers use more temporary parental leave than partnered mothers. Further, within the group of lone mothers, those with higher socioeconomic status take less temporary parental leave...... than those with lower socioeconomic status, whereas no such differences are found within the group of partnered mothers. One possible interpretation is that signaling costs negatively influence the utilization of temporary parental leave for lone mothers....

  4. Fungal Distribution and Varieties Resistance to Kernel Discoloration in Korean Two-rowed Barley

    OpenAIRE

    Sang-Hyun Shin; Eun-Jo Seo; Jae-Seong Choi; JungKwan Lee; Jong-Chul Park; Chun-Sik Kang

    2013-01-01

    Barley kernel discoloration (KD) leads to substantial loss in value through downgrading and discounting of malting barley. The objective of this research is to investigate fungal distribution and varieties resistance to KD in Korean two-rowed barley. Several fungal organisms including Alternaria spp., Fusarium spp., Aspergillus spp., Epicoccum spp. and Rhizopus spp. were isolated from Korean two-rowed barley representing KD. The symptoms of KD were brown and black discolorations o...

  5. Effect of herbicide clomazone on photosynthetic processes in primary barley (Hordeum vulgare L.) leaves

    Czech Academy of Sciences Publication Activity Database

    Kaňa, R.; Špundová, M.; Ilík, P.; Lazár, D.; Klem, K.; Tomek, P.; Nauš, J.; Prášil, Ondřej

    2004-01-01

    Roč. 78, - (2004), s. 161-170 ISSN 0048-3575 R&D Projects: GA ČR GA522/00/1274; GA ČR GP522/01/P098 Institutional research plan: CEZ:AV0Z5020903 Keywords : clomazone * herbicide * photosynthesis Subject RIV: ED - Physiology Impact factor: 1.133, year: 2004

  6. Engineering of the aspartate family biosynthetic pathway in barley (Hordeum vulgare L.) by transformation with heterologous genes encoding feed-back-insensitive aspartate kinase and dihydrodipicolinate synthase

    DEFF Research Database (Denmark)

    Brinch-Pedersen, H.; Galili, G.; Sørensen, K.

    1996-01-01

    In prokaryotes and plants the synthesis of the essential amino acids lysine and threonine is predominantly regulated by feed-back inhibition of aspartate kinase (AK) and dihydrodipicolinate synthase (DHPS). In order to modify the flux through the aspartate family pathway in barley and enhance...... the accumulation of the corresponding amino acids, we have generated transgenic barley plants that constitutively express mutant Escherichia coli genes encoding lysine feed-back insensitive forms of AK and DHPS. As a result, leaves of primary transformants (T0) exhibited a 14-fold increase of free lysine and an 8......, no differences were observed in the composition of total amino acids. The introduced genes were inherited in the T1 generation where enzymic activities revealed a 2.3-fold increase of AK activity and a 4.0-9.5-fold increase for DHPS. T1 seeds of DHPS transformants showed the same changes in free amino acids...

  7. Fusarium infection and trichothecenes in barley and its comparison with wheat

    NARCIS (Netherlands)

    Janssen, Esmee; Liu, C.; Fels, van der H.J.

    2018-01-01

    Barley is a small-grain cereal that can be infected by Fusarium spp. resulting in reduced quality and safety of harvested barley (products). Barley and other small-grain cereals are commonly studied together for Fusarium infection and related mycotoxin contamination, since the infection and its

  8. Interaction between powdery mildew and barley with ¤mlo5¤ mildew resistance

    DEFF Research Database (Denmark)

    Lyngkjær, M.F.; Østergård, Hanne

    1998-01-01

    Powdery mildew infection of barley with the mlo5 barley powdery mildew resistance gene was examined, using near-isogenic barley lines, with and without mlo5 resistance, and two near-isogenic powdery mildew isolates, HL3/5 and GE3 with high (virulent) or low (avirulent) penetration efficiency...

  9. Transgressive segregation for very low and high levels of basal resistance to powdery mildew in barley

    NARCIS (Netherlands)

    Aghnoum, R.; Niks, R.E.

    2011-01-01

    Basal resistance of barley to powdery mildew is a quantitatively inherited trait that limits the growth and sporulation of barley powdery mildew pathogen by a non-hypersensitive mechanism of defense. Two experimental barley lines were developed with a very high (ErBgh) and low (EsBgh) level of basal

  10. Long-term reconstitution of dry barley increased phosphorus digestibility in pigs

    DEFF Research Database (Denmark)

    Ton Nu, Mai Anh; Blaabjerg, Karoline; Poulsen, Hanne Damgaard

    of reconstitution compared to dry stored barley on phosphorus (P) digestibility in pigs. Materials and Methods: Dry barley (13% moisture; phytate P, 1.7 g/kg DM) was rolled and stored directly or reconstituted with water to produce rolled barley with 35% moisture that was stored in air-tight conditions. After 49...

  11. Effects of Net Blotch ( Pyrenophora teres ) on Malt Barley Yield and ...

    African Journals Online (AJOL)

    Barley (Hordeum vulgare L.) production is constrained by diseases such as net blotch caused by Pyrenophora teres Drechsl. The objectives of this study were to assess the effects of net blotch disease on malt barley yield and grain quality under natural infection. Four malt barley varieties (Beka, HB 120, HB 52 and Holker), ...

  12. Water uptake in barley grain: Physiology; genetics and industrial applications.

    Science.gov (United States)

    Cu, Suong; Collins, Helen M; Betts, Natalie S; March, Timothy J; Janusz, Agnieszka; Stewart, Doug C; Skadhauge, Birgitte; Eglinton, Jason; Kyriacou, Bianca; Little, Alan; Burton, Rachel A; Fincher, Geoffrey B

    2016-01-01

    Water uptake by mature barley grains initiates germination and is the first stage in the malting process. Here we have investigated the effects of starchy endosperm cell wall thickness on water uptake, together with the effects of varying amounts of the wall polysaccharide, (1,3;1,4)-β-glucan. In the latter case, we examined mutant barley lines from a mutant library and transgenic barley lines in which the (1,3;1,4)-β-glucan synthase gene, HvCslF6, was down-regulated by RNA interference. Neither cell wall thickness nor the levels of grain (1,3;1,4)-β-glucan were significantly correlated with water uptake but are likely to influence modification during malting. However, when a barley mapping population was phenotyped for rate of water uptake into grain, quantitative trait locus (QTL) analysis identified specific regions of chromosomes 4H, 5H and 7H that accounted for approximately 17%, 18% and 11%, respectively, of the phenotypic variation. These data indicate that variation in water uptake rates by elite malting cultivars of barley is genetically controlled and a number of candidate genes that might control the trait were identified under the QTL. The genomics data raise the possibility that the genetic variation in water uptake rates might be exploited by breeders for the benefit of the malting and brewing industries. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Detection of Ustilago nuda (Jensen Rostrup in winter barley seed

    Directory of Open Access Journals (Sweden)

    Ignjatov Maja

    2011-01-01

    Full Text Available Barley is one of the most important cereals grown in our agroecological conditions. The causal agent of loose smut on barley Ustilago nuda (Jensen Rostrup occurs frequently as varieties susceptible to this pathogen are present in the production. Disease symptoms are manifested on barley head (spike. Parasite is transmitted by seed (seedborne and stays in the embryo tissue of the infected kernel as dormant mycelium. Recommended method for detection of U. nuda is given by ISTA Rules (method 7-013. In tests, nine samples (weighing 120 g each of naturally infected barley seed (about 1000 seeds, depending on the absolute mass of seed were examined, observed and described using a Zeiss microscope with sub stage illumination with magnification range x 40 or higher. Mycelium of the fungus approximately 3 μ thick, golden brown in colour was detected and visible without a stain. The percentage of infected embryos in the examined samples of barley seeds ranged from 0.8% to 5.2%.

  14. Aggressiveness of powdery mildew on 'ml-o'- resistant barley

    International Nuclear Information System (INIS)

    Andersen, Lars

    1990-01-01

    The ml-o genes in barley are important sources in breeding for resistance against the barley powdery mildew fungus (Erysiphe graminis). The resistance mechanism is a rapid formation of a large callose containing cell wall apposition at the site of the pathogen's infection attempt. This reduces the chances of infection to almost nil in all epidermal cells, except in the small subsidiary cells, in which appositions are rarely formed. Small mildew colonies from infections in subsidiary cells may be seen on the otherwise resistant leaf. This is described by the infection type 0/(4). Mildew isolate HL 3 selected by SCHWARZBACH has increased aggressiveness. No ml-o-virulent isolates are known. However, ml-o-resistant varieties when grown extensively in Europe, will introduce field selection for mildew pathotypes with aggressiveness or virulence to ml-o resistance. Studies on increased aggressiveness require new methods. The material comprises two powdery mildew isolates: GE 3 without ml-o aggressiveness and the aggressive HL 3/5; and two near-isogenic barley lines in Carlsberg II: Riso 5678(R) with the recessive mutant resistance gene ml-o5 and Riso 5678(S) with the wild-type gene for susceptibility. Latent period and disease efficiency show no significant differences between the two isolates on the susceptible barley line (S) but the isolates differ from each other on the resistant barley line

  15. Simultaneous Detection of Barley Virus Diseases in Korea

    Directory of Open Access Journals (Sweden)

    Bong-Choon Lee

    2017-12-01

    Full Text Available Barley mild mosaic virus (BaMMV, Barley yellow mosaic virus (BaYMV and Barley yellow dwarf virus (BYDV have been identified as an important causative agents for an economically important disease of winter barley in Korea. In this study, a multiplex reverse transcription polymerase chain reaction (mRT-PCR method was used for the simultaneous detection. Three sets of virus-specific primers targeted to the capsid protein coding genes of BaMMV, BaYMV and BYDV were used to amplify fragments that were 594 bp, 461 bp, and 290 bp, respectively. Several sets of primers for each target virus were evaluated for their sensitivity and specificity by multiplex RT-PCR. The optimum primer concentrations and RT-PCR conditions were determined for the multiplex RT-PCR. The mRT-PCR assay was found to be a better and rapid virus diagnostic tool of specific barley diseases and potential for investigating the epidemiology of these viral diseases.

  16. The project of mutation breeding in barley (first report)

    International Nuclear Information System (INIS)

    2010-01-01

    Barley is a second main crop with the production of 7 million tons per year and 3,5 million hectare cultivation area in Turkey. Because of wateer deficiency, cereals cultivated in Central Anatolian region. Barley is well adapted to dry farming system besides it is basic food for animal husbandry and main raw material for brewery industry. the main problems in barley production are drought disease epidemic and increasing salinity gradually. Main purposes of our project is to increase resistance and tolerence to this stress factors. In order to reach to our aim we have been using mutation breeding techniques and conventional breeding methods. This Project has been started with irradiation of barley seeds with different gamma ray doses. After that resistant and tolerant mutant has been selected most of these mutanys have resistance and tolerance to different disease and stress conditions. During the selection procedure, hydroponics and tissue culture techniques have been applied to improve the selection efficiency. Up to now, promising barley mutant lines 71 that have earliness (30 days) than parents and because of that reason that escape from drought period. Disease tests of our mutant lines have been conducted under controlled conditions and tolerant lines have been determined under the high the high epidemic conditions. Salt tolerance studies have been applied under hydroponics conditions and salt tolerant mutant have been determined under 180-200mMolNaCl concentration. All mutant lines are carried out to preliminary yield trials for their evaluation

  17. Identification of a Phytase Gene in Barley (Hordeum vulgare L.)

    Science.gov (United States)

    Dai, Fei; Qiu, Long; Ye, Lingzhen; Wu, Dezhi; Zhou, Meixue; Zhang, Guoping

    2011-01-01

    Background Endogenous phytase plays a crucial role in phytate degradation and is thus closely related to nutrient efficiency in barley products. The understanding of genetic information of phytase in barley can provide a useful tool for breeding new barley varieties with high phytase activity. Methodology/Principal Findings Quantitative trait loci (QTL) analysis for phytase activity was conducted using a doubled haploid population. Phytase protein was purified and identified by the LC-ESI MS/MS Shotgun method. Purple acid phosphatase (PAP) gene was sequenced and the position was compared with the QTL controlling phytase activity. A major QTL for phytase activity was mapped to chromosome 5 H in barley. The gene controlling phytase activity in the region was named as mqPhy. The gene HvPAP a was mapped to the same position as mqPhy, supporting the colinearity between HvPAP a and mqPhy. Conclusions/Significance It is the first report on QTLs for phytase activity and the results showed that HvPAP a, which shares a same position with the QTL, is a major phytase gene in barley grains. PMID:21533044

  18. Identification of a phytase gene in barley (Hordeum vulgare L..

    Directory of Open Access Journals (Sweden)

    Fei Dai

    Full Text Available BACKGROUND: Endogenous phytase plays a crucial role in phytate degradation and is thus closely related to nutrient efficiency in barley products. The understanding of genetic information of phytase in barley can provide a useful tool for breeding new barley varieties with high phytase activity. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative trait loci (QTL analysis for phytase activity was conducted using a doubled haploid population. Phytase protein was purified and identified by the LC-ESI MS/MS Shotgun method. Purple acid phosphatase (PAP gene was sequenced and the position was compared with the QTL controlling phytase activity. A major QTL for phytase activity was mapped to chromosome 5 H in barley. The gene controlling phytase activity in the region was named as mqPhy. The gene HvPAP a was mapped to the same position as mqPhy, supporting the colinearity between HvPAP a and mqPhy. CONCLUSIONS/SIGNIFICANCE: It is the first report on QTLs for phytase activity and the results showed that HvPAP a, which shares a same position with the QTL, is a major phytase gene in barley grains.

  19. The Genetic Architecture of Barley Plant Stature

    Science.gov (United States)

    Alqudah, Ahmad M.; Koppolu, Ravi; Wolde, Gizaw M.; Graner, Andreas; Schnurbusch, Thorsten

    2016-01-01

    Plant stature in temperate cereals is predominantly controlled by tillering and plant height as complex agronomic traits, representing important determinants of grain yield. This study was designed to reveal the genetic basis of tillering at five developmental stages and plant height at harvest in 218 worldwide spring barley (Hordeum vulgare L.) accessions under greenhouse conditions. The accessions were structured based on row-type classes [two- vs. six-rowed] and photoperiod response [photoperiod-sensitive (Ppd-H1) vs. reduced photoperiod sensitivity (ppd-H1)]. Phenotypic analyses of both factors revealed profound between group effects on tiller development. To further verify the row-type effect on the studied traits, Six-rowed spike 1 (vrs1) mutants and their two-rowed progenitors were examined for tiller number per plant and plant height. Here, wild-type (Vrs1) plants were significantly taller and had more tillers than mutants suggesting a negative pleiotropic effect of this row-type locus on both traits. Our genome-wide association scans further revealed highly significant associations, thereby establishing a link between the genetic control of row-type, heading time, tillering, and plant height. We further show that associations for tillering and plant height are co-localized with chromosomal segments harboring known plant stature-related phytohormone and sugar-related genes. This work demonstrates the feasibility of the GWAS approach for identifying putative candidate genes for improving plant architecture. PMID:27446200

  20. Transglycosylation by barley α-amylase 1

    DEFF Research Database (Denmark)

    Mótyán, János A.; Fazekas, Erika; Mori, Haruhide

    2011-01-01

    The transglycosylation activity of barley α-amylase 1 (AMY1) and active site AMY1 subsite mutant enzymes was investigated. We report here the transferase ability of the V47A, V47F, V47D and S48Y single mutants and V47K/S48G and V47G/S48D double mutant AMY1 enzymes in which the replaced amino acids...... play important role in substrate binding at subsites at −3 through −5. Although mutation increases the transglycosylation activity of enzymes, in the presence of acceptors the difference between wild type and mutants is not so significant. Oligomer transfer reactions of AMY1 wild type and its mutants...... as donor. 4-Methylumbelliferyl-α-d-maltoside, -maltotrioside, -maltotetraoside and -maltopentaoside have been synthesized. Products were identified by MALDI-TOF MS. 1H and 13C NMR analyses showed that AMY1 V47F preserved the stereo- and regioselectivity. The produced MU-α-d-MOSs of degree of polymerization...

  1. Chemical weed control in barley (hordeum vulgare)

    International Nuclear Information System (INIS)

    Sarwar, M.; Hassan, S.W.; Abid, A.A.

    2008-01-01

    Effect of two different pre-emergence herbicides i.e. Terbutryn (lgron-500FW) A, 1.01.25 kg a.t. ha/sup -1/ and Flurochloridone (Racer-25 CS) a 0.31, 0.37, 0.44, 0.50 and 0.56 Kg a.i. ha/sup -1/ on weeds and yield of barley wad studied under field conditions hb/sup -1/. All the herbicides significantly reduce the dry weight of weed Maximum reduction (70%) was observed in terbutryn a 1.0 Kg a.i. ha/sup -1/ Growth and yield parameters like number of spike lets per spike. Number of grams per spike. 1000-grain weight. Biological yield. Grain yield straw yield and harvest index showed significant response to various herbicides doses under study. Application of Flurochloridone (Racer-25 (CS) a 0.44 kg a.i. ha/sup -1/ and Terbutryn (lgran-500 FW) a 1.0 kg a.i). The data further revealed that in general all herbicide application treatments exhibited superior performance in respect of growth and yield over control. (author)

  2. Yield and competition in barley variety mixtures

    Directory of Open Access Journals (Sweden)

    Kari Jokinen

    1991-09-01

    Full Text Available Competition between spring barley varieties and yield performance of two-, three and four-variety mixtures were studied in two replacement series field experiments. In the first experiment, repeated in three successive years (1983 —85 the components were the six-row varieties Agneta, Arra, Hja-673 and Porno. In the second experiment (1984, including two nitrogen doses (50 and 100 kgN/ha, both six-row (Agneta, Pomo and two-row (Ida, Kustaa varieties were used. Arra in the first and Agneta in the second experiment were the most competitive varieties. The results suggested that the fast growth of Arra at the beginning promoted its competitive ability. Increase in available nitrogen usually strengthened the competitiveness of Agneta. The observed competitive differences between varieties were not related to the earliness of a variety, neither to the morphological characters (two- and six-row varieties nor to the grain yield of a variety grown alone. The competitive ability was not always a stable character, the dominant suppression relationship varying from one environment to another (e.g. growing season, nitrogen dose. The observed overyielding was not statistically significant. The ratio of actual to expected yield and the relative yield total of several mixtures exceeded slightly one. As a conclusion, the yield advantage of mixtures was marginal. As a rule, the mixtures were not more stable than monocultures as determined by the coefficient of variation. However, the yield of some mixtures varied less than the yield of the most stable monoculture.

  3. Barley yellow dwarf virus in barley crops in Tunisia: prevalence and molecular characterization

    Directory of Open Access Journals (Sweden)

    Asma NAJAR

    2017-05-01

    Full Text Available A field survey was conducted in Tunisia in the North-Eastern regions (Bizerte, CapBon and Zaghouan, the North-Western region (Kef and the Central-Eastern region (Kairouan during the 2011/2012 growing season, in order to determine the incidence and the geographic distribution of Barley yellow dwarf virus (BYDVs in barley fields. Tissue blot immunoassays (TBIA showed that BYDV was most common in Zaghouan (incidence 14%, Cap Bon (14% and Bizerte (35%, in randomly collected samples from these three locations.Among the different BYDVs identified, BYDV-PAV (64% was the most common followed by BYDV-MAV (16% and CYDV-RPV (3%. The coat protein gene sequences of six isolates collected from different regions shared >98% pairwise similarity. In comparisons with other BYDV sequences from around the world, the Tunisian sequences shared greatest homology with isolates 109 and ASL1 from the United States of America and Germany (≈97%, and <90% with all other isolate sequences available in public databases.

  4. In vitro screening of durum wheat against water-stress mediated through polyethylene glycol

    Directory of Open Access Journals (Sweden)

    Nadia Sandra Kacem

    2017-06-01

    Full Text Available Three durum wheat (Triticum durum Desf. genotypes with three levels of drought tolerance were screened in order to evaluate their response to water stress at callus induction and plant regeneration levels. Significant differences were observed among the genotypes, and polyethylene glycol (PEG levels used, and their interactions were however, significant for all the studied characters. Increase in PEG concentration increased the time required for callus initiation and reduced the number of calli frequency of embryogenic structures and number of plants regenerated, showing the adverse effect of PEG on the somatic embryogenesis developmental., under in vitro conditions tested, and Djenah Khetifa was the most tolerant genotype, followed by Oued Zenati and Waha. This pattern was per their drought tolerance behavior under field conditions. Principal component analysis (PCA showed that 95.56% of the total variation was explained by the first two principal components. Biplot analysis allowed the stress-tolerant genotype to be distinguished from the two less tolerant genotypes. Time required for callus initiation was strongly negatively correlated with all other studied traits. These traits can be recommended as suitable selection criteria for screening drought-tolerant genotypes. The selected cells and plants will provide a tool for determining the mechanisms involved in tolerance to water stress.

  5. Hormonal changes in the grains of rice subjected to water stress during grain filling.

    Science.gov (United States)

    Yang, J; Zhang, J; Wang, Z; Zhu, Q; Wang, W

    2001-09-01

    Lodging-resistant rice (Oryza sativa) cultivars usually show slow grain filling when nitrogen is applied in large amounts. This study investigated the possibility that a hormonal change may mediate the effect of water deficit that enhances whole plant senescence and speeds up grain filling. Two rice cultivars showing high lodging resistance and slow grain filling were field grown and applied with either normal or high amount nitrogen (HN) at heading. Well-watered and water-stressed (WS) treatments were imposed 9 days post anthesis to maturity. Results showed that WS increased partitioning of fixed (14)CO(2) into grains, accelerated the grain filling rate but shortened the grain filling period, whereas the HN did the opposite way. Cytokinin (zeatin + zeatin riboside) and indole-3-acetic acid contents in the grains transiently increased at early filling stage and WS treatments hastened their declines at the late grain filling stage. Gibberellins (GAs; GA(1) + GA(4)) in the grains were also high at early grain filling but HN enhanced, whereas WS substantially reduced, its accumulation. Opposite to GAs, abscisic acid (ABA) in the grains was low at early grain filling but WS remarkably enhanced its accumulation. The peak values of ABA were significantly correlated with the maximum grain filling rates (r = 0.92**, P water stress during grain filling, especially a decrease in GAs and an increase in ABA, enhances the remobilization of prestored carbon to the grains and accelerates the grain filling rate.

  6. Use of subirrigation for water stress imposition in a semi-continuous CO2-exchange system

    Directory of Open Access Journals (Sweden)

    Rhuanito Soranz Ferrarezi

    2015-08-01

    Full Text Available The objectives of this work were to evaluate the effects of distinct moisture contents to trigger subirrigation on salvia photosynthesis and plant growth, and to verify the feasibility of subirrigation use in water stress imposition research in this crop. We evaluated two substrate volumetric water contents (VWC as treatments (0.2 and 0.4 m3 m-3 to trigger subirrigation, with 4 replications. Each replication was composed of 10 plants. An automated semi-continuous multi-chamber crop CO2-exchange system was used, with capacitance soil moisture sensors for continuous moisture monitoring. Manual subirrigation with nutrient solution was performed when VWC dropped below the thresholds. In both treatments, the values of net photosynthesis, daily carbon gain and carbon use efficiency reduced over time, from 2 to 1.1 μmol s-1 from 2.2 to 1 μmol d-1 from 0.7 to 0.45 mol mol-1, respectively, in both soil moisture treatments. Total shoot dry mass (p=0.0129, shoot height in the tip of the highest flower (p<0.0001 and total leaf area (p=0.0007 were statistically higher at 0.4 m3 m-3 treatment. The subirrigation system was not efficient to impose water stress, due to excessive variation on VWC values after each irrigation event in both treatments. Higher soil moisture promoted positive plant growth responses in salvia cultivated by subirrigation.

  7. Ecophysiological modeling of grapevine water stress in Burgundy terroirs by a machine-learning approach

    Directory of Open Access Journals (Sweden)

    Luca eBrillante

    2016-06-01

    Full Text Available In a climate change scenario, successful modeling of the relationships between plant-soil-meteorology is crucial for a sustainable agricultural production, especially for perennial crops. Grapevines (Vitis vinifera L. cv Chardonnay located in eight experimental plots (Burgundy, France along a hillslope were monitored weekly for three years for leaf water potentials, both at predawn (Ψpd and at midday (Ψstem. The water stress experienced by grapevine was modeled as a function of meteorological data (minimum and maximum temperature, rainfall and soil characteristics (soil texture, gravel content, slope by a gradient boosting machine. Model performance was assessed by comparison with carbon isotope discrimination (δ13C of grape sugars at harvest and by the use of a test-set. The developed models reached outstanding prediction performance (RMSE < 0.08 MPa for Ψstem and < 0.06 MPa for Ψpd, comparable to measurement accuracy. Model predictions at a daily time step improved correlation with δ13C data, respect to the observed trend at a weekly time scale. The role of each predictor in these models was described in order to understand how temperature, rainfall, soil texture, gravel content and slope affect the grapevine water status in the studied context. This work proposes a straight-forward strategy to simulate plant water stress in field condition, at a local scale; to investigate ecological relationships in the vineyard and adapt cultural practices to future conditions.

  8. Ecophysiological Modeling of Grapevine Water Stress in Burgundy Terroirs by a Machine-Learning Approach.

    Science.gov (United States)

    Brillante, Luca; Mathieu, Olivier; Lévêque, Jean; Bois, Benjamin

    2016-01-01

    In a climate change scenario, successful modeling of the relationships between plant-soil-meteorology is crucial for a sustainable agricultural production, especially for perennial crops. Grapevines (Vitis vinifera L. cv Chardonnay) located in eight experimental plots (Burgundy, France) along a hillslope were monitored weekly for 3 years for leaf water potentials, both at predawn (Ψpd) and at midday (Ψstem). The water stress experienced by grapevine was modeled as a function of meteorological data (minimum and maximum temperature, rainfall) and soil characteristics (soil texture, gravel content, slope) by a gradient boosting machine. Model performance was assessed by comparison with carbon isotope discrimination (δ(13)C) of grape sugars at harvest and by the use of a test-set. The developed models reached outstanding prediction performance (RMSE < 0.08 MPa for Ψstem and < 0.06 MPa for Ψpd), comparable to measurement accuracy. Model predictions at a daily time step improved correlation with δ(13)C data, respect to the observed trend at a weekly time scale. The role of each predictor in these models was described in order to understand how temperature, rainfall, soil texture, gravel content and slope affect the grapevine water status in the studied context. This work proposes a straight-forward strategy to simulate plant water stress in field condition, at a local scale; to investigate ecological relationships in the vineyard and adapt cultural practices to future conditions.

  9. In silico analysis of ESTs from roots of Rangpur lime (Citrus limonia Osbeck under water stress

    Directory of Open Access Journals (Sweden)

    Raquel L. Boscariol-Camargo

    2007-01-01

    Full Text Available CitEST project resulted in the construction of cDNA libraries from different Citrus sp. tissues under various physiological conditions. Among them, plantlets of Rangpur lime were exposed to hydroponic conditions with and without water stress using PEG6000. RNA from roots was obtained and generated a total of 4,130 valid cDNA reads, with 2,020 from the non-stressed condition and 2,110 from the stressed set. Bioinformatic analyses measured the frequency of each read in the libraries and yielded an in silico transcriptional profile for each condition. A total of 40 contigs were differentially expressed and allowed to detect up-regulated homologue sequences to well known genes involved in stress response, such as aquaporins, dehydrin, sucrose synthase, and proline-related synthase. Some sequences could not be classified by using FunCat and remained with an unknown function. A large number of sequences presented high similarities to annotated genes involved with cell energy, protein synthesis and cellular transport, suggesting that Rangpur lime may sustain active cell growth under stressed condition. The presence of membrane transporters and cell signaling components could be an indication of a coordinated morphological adaptation and biochemical response during drought, helping to explain the higher tolerance of this rootstock to water stress.

  10. Physiological performance of sesame seeds under the water stress at different temperatures

    Directory of Open Access Journals (Sweden)

    Dayana Silva de Medeiros

    2015-10-01

    Full Text Available Sesame (Sesamum indicum L. shows great economic potential because it can be explored by the national as well as the international market. It can be grown in the second season when it is subject to less favorable weather conditions such as drought during the sowing and emergence. Given this the objective was to evaluate the effect of water stress induced by polyethylene glycol solutions (PEG 6000 at different temperatures in order to asses the physiological quality of sesame seeds. In this work, were used PEG 6000 with different osmotic potentials (0.0 control and (-0.2, –0.4, –0.6, –0.8, –1.0 –1,2 and –1.4 MPa at temperatures of 25, 30 and 35 °C. For determine the effect of the treatments it was evaluated seed germination and vigor (first count and length of the primary root and shoot, in a completely randomized, with four replications. The sesame seeds are affected by water stress, with significant reductions in germination and vigor. A temperature of 30 °C favored the germination performance in less restrictive water potentials.

  11. Climatic and anthropogenic changes in Western Switzerland: Impacts on water stress.

    Science.gov (United States)

    Milano, Marianne; Reynard, Emmanuel; Köplin, Nina; Weingartner, Rolf

    2015-12-01

    Recent observed hydro-climatic changes in mountainous areas are of concern as they may directly affect capacity to fulfill water needs. The canton of Vaud in Western Switzerland is an example of such a region as it has experienced water shortage episodes during the past decade. Based on an integrated modeling framework, this study explores how hydro-climatic conditions and water needs could evolve in mountain environments and assesses their potential impacts on water stress by the 2060 horizon. Flows were simulated based on a daily semi-distributed hydrological model. Future changes were derived from Swiss climate scenarios based on two regional climate models. Regarding water needs, the authorities of the canton of Vaud provided a population growth scenario while irrigation and livestock trends followed a business-as-usual scenario. Currently, the canton of Vaud experiences moderate water stress from June to August, except in its Alpine area where no stress is noted. In the 2060 horizon, water needs could exceed 80% of the rivers' available resources in low- to mid-altitude environments in mid-summer. This arises from the combination of drier and warmer climate that leads to longer and more severe low flows, and increasing urban (+40%) and irrigation (+25%) water needs. Highlighting regional differences supports the development of sustainable development pathways to reduce water tensions. Based on a quantitative assessment, this study also calls for broader impact studies including water quality issues. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Physiological behaviors and recovery responses of four galician grapevine (Vitis vinifera L. cultivars under water stress

    Directory of Open Access Journals (Sweden)

    Islam M. T.

    2012-11-01

    Full Text Available Gas exchange parameters and chlorophyll fluorescence of four pot grown Galician grapevines (Vitis vinifera L. cv. Albariño, Brancellao, Godello and Treixadura were examined under different levels of water stress in greenhouse. After extreme stress, gas exchange recovery responses were evaluated. Average ΨPD for control and stressed plants were -0.4MPa and -1.45MPa respectively. All varieties showed gradual declining of all gas exchange parameters (gs, E and A with increasing of stress periods. Under stressed conditions, Albariño and Godello showed higher CO2 assimilation rate. At the end of stress period leaf defoliation was found in Albariño and Brancellao. Gas exchange recovery was higher for both Godello and Treixadura. A better response of auxiliary bud recovery was present in Albariño than in Brancellao. Close correlations between water stress and gas exchange parameters were found and it varies on genotype. Albariño, Godello and Treixadura followed same diurnal patterns of gas exchange rate for control and stressed plant respectively. Diurnal pattern of CO2 assimilation rate of all tested varieties followed gs and E. Only Brancellao showed treatment effect on mid-day Fv/Fm. Among four varieties photoinhibition was only found in Brancellao. At stressed condition physiological responses of grapevines were genotype depended.

  13. Examining Adaptations to Water Stress Among Farming Households in Sri Lanka's Dry Zone

    Science.gov (United States)

    Williams, N. E.; Carrico, A.

    2016-12-01

    Climate change is increasing water scarcity in Sri Lanka's primary rice-farming zone. Whether these changes will undermine the national-level food security that Sri Lanka has worked to develop since their independence depends upon the ability of the small-scale farmers that dominate rice production and the institutions that support them to overcome the challenges presented by changing water availability. Using household survey data collected in 13 rice farming communities throughout Sri Lanka, this research explores how water stressed farmers are working to adapt to changing conditions and how the strategies they employ impact rice yields. Our analyses reveal that farmers' abilities to access irrigation infrastructure is the most important factor shaping the rice yields of water stressed Sri Lanka farmers. Notably, however, our research also identified farmers' use of hybrid, 'short duration' seed varietals to be the only climate adaptation strategy being promoted by agricultural extension services to have a significant positive impact on farmers' yields. These findings provide encouraging evidence for policies that promote plant breeding and distribution in Sri Lanka as a means to buffer the food system to climate change.

  14. Response of Short Duration Tropical Legumes and Maize to Water Stress: A Glasshouse Study

    Directory of Open Access Journals (Sweden)

    Hossain Sohrawardy

    2014-01-01

    Full Text Available The study was conducted as a pot experiment in the tropical glasshouse to evaluate the response of grain legumes (Phaseolus vulgaris, Vigna unguiculata, and Lablab purpureus in comparison to maize (Zea mays and estimate their potential and performance. Two experiments were established using completely randomized design. Physiological measurements (stomatal conductance, photosynthetic activities, and transpiration rates were measured using LCpro instrument. Scholander bomb was used for the measurement of plant cell water potential. Significant difference was observed in different plant species with increase of different water regimes. Among the legumes, L. purpureus showed better response in water stressed conditions. At the beginning, in dry watered treatment the photosynthetic rate was below 0 µmol m−2 s−1 and in fully watered condition it was 48 µmol m−2 s−1. In dry treatment, total dry weight was 10 g/pot and in fully watered condition it was near to 20 g/pot in P. vulgaris. The study concludes that water stress condition should be taken into consideration for such type of crop cultivation in arid and semiarid regions.

  15. Improvement of quinoa and barley through induced mutations and biotechnology

    International Nuclear Information System (INIS)

    Siles, A.Z.; Miranda, L.S.

    2001-01-01

    The main cropping problems in the Bolivian highlands are the long growing period of barley, high degree of environmental influence on the performance of quinoa, and low soil moisture at sowing time, leading to low germination rate and poor stands, and frost or chilling damages. The program aimed to establish protocols for induction of mutations with X rays and chemical mutagens (NaN 3 , MNH, EMS) in quinoa, barley, native forage species and forest plants and to obtain mutant lines, especially in barley and quinoa; and to establish callus regeneration in quinoa and micropropagation of kenua (Polilepis). The project is still in its study stages, hence further evaluations are needed before firm conclusions are drawn. (author)

  16. Occurrence of barley leaf disease and control strategies in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Lise Nistrup; Ørum, Jens Erik; Heick, Thies Marten

    Barley (Hordeum vulgare) is one of the major crops in Denmark and of special importance for malting and for pig feed. In 2016, the crop was grown covering a total area of 700,000 ha; approximately 25% of arable area in Denmark. To ensure high yield of around 60 dt ha-1, disease-tolerant cultivars...... have proven to be quite effective against all leaf diseases, aside from brown rust and mildew. Denmark has a national record system for pesticide usages. All farmers upload their fungicide use by crop, creating a good basis for assessing the differences in use pattern across different regions...... and fungicide treatments are required. Each year, barley cultivars are assessed for susceptibility towards leaf diseases in national observation plots. The most predominant fungal leaf diseases in Denmark are barley scald (Rhynchosporium secalis), net blotch (Pyrenophora teres), brown rust (Puccinia hordei...

  17. Regeneration of the Barley Zygote in In Vitro Cultured Ovules

    DEFF Research Database (Denmark)

    Holme, Inger B; Brinch-Pedersen, Henrik; Lange, Mette

    2010-01-01

    In vitro cultures of zygotes and small embryos carry a lot of potential for studying plant embryogenesis and are also highly relevant for plant biotechnology. Several years ago we established an in vitro ovule culture technique for barley that allows the regeneration of plants from zygotes (Holm et...... culture ability in immature embryo culture i.e. Femina, Salome and Corniche. Barley spikes were emasculated and hand pollinated 3 days after emasculation. In barley, fertilization takes place one hour after pollination and ovules with fertilized egg cells could therefore be isolated one hour after...... pollination. Ovules were grown for 3 weeks on a culture medium where after embryos could be isolated and transferred to regeneration medium. An average of 1.2 green plantlets per ovule could be regenerated from 50 % of the isolated ovules. No genotypic differences were found on embryo induction...

  18. Response of CO and H2 uptake to extremes of water stress in saline and non-saline soils

    Science.gov (United States)

    King, G.

    2017-12-01

    Neither carbon monoxide (CO) nor hydrogen (H2) have direct impacts on radiative forcing, but both play important roles in tropospheric chemistry. Soils affect both the fate and significance of atmospheric CO and H2 by acting as strong global gas sinks ( 15% and >75 %, respectively), but much remains unknown about the microbiology of these gases, including responses to key environmental drivers. The role of water availability, measured as water potential, has been addressed to a limited extent by earlier studies with results suggesting that CO and H2 uptake are strongly limited by water stress. However recent results indicate a much greater tolerance of water stress than previously suspected. Ex situ assays have shown that non-saline playa soils from the Alvord Basin (Oregon, USA) consumed atmospheric and exogenous hydrogen and CO under conditions of severe water stress. CO uptake occurred at water potentials values considered optimal for terrestrial bacterial growth. Surface soils that had been exposed to water potentials as low as -300 MPa also oxidized CO and H2 after brief equilibration at higher potentials (less water stress), indicating remarkable tolerance of desiccating conditions. Tolerance to water stress for CO and H2 uptake was also observed for soils from a montane rainforest (Hawai`i, USA). However, unlike playa soils rainforest soils seldom experience extended drought that would select for desiccation tolerance. While CO uptake by forest soils was more sensitive to water stress (limits -10MPa) than in playa soils, H2 uptake was observed at -90 MPa to -100 MPa. Tolerance at these levels might be due to the formation of intracellular water that limits the local effects of stress. Comparisons of water stress responses between saline and non-saline soils further suggested that communities of CO- and H2-oxidizing were generally robust with respect to stresses resulting from solute and matric effects. Collectively the results indicate that models of global

  19. The role of mesophyll conductance during water stress and recovery in tobacco (Nicotiana sylvestris): acclimation or limitation?

    Science.gov (United States)

    Galle, Alexander; Florez-Sarasa, Igor; Tomas, Magdalena; Pou, Alicia; Medrano, Hipolito; Ribas-Carbo, Miquel; Flexas, Jaume

    2009-01-01

    While the responses of photosynthesis to water stress have been widely studied, acclimation to sustained water stress and recovery after re-watering is poorly understood. In particular, the factors limiting photosynthesis under these conditions, and their possible interactions with other environmental conditions, are unknown. To assess these issues, changes of photosynthetic CO(2) assimilation (A(N)) and its underlying limitations were followed during prolonged water stress and subsequent re-watering in tobacco (Nicotiana sylvestris) plants growing under three different climatic conditions: outdoors in summer, outdoors in spring, and indoors in a growth chamber. In particular, the regulation of stomatal conductance (g(s)), mesophyll conductance to CO(2) (g(m)), leaf photochemistry (chlorophyll fluorescence), and biochemistry (V(c,max)) were assessed. Leaf gas exchange and chlorophyll fluorescence data revealed that water stress induced a similar degree of stomatal closure and decreased A(N) under all three conditions, while V(c,max) was unaffected. However, the behaviour of g(m) differed depending on the climatic conditions. In outdoor plants, g(m) strongly declined with water stress, but it recovered rapidly (1-2 d) after re-watering in spring while it remained low many days after re-watering in summer. In indoor plants, g(m) initially declined with water stress, but then recovered to control values during the acclimation period. These differences were reflected in different velocities of recovery of A(N) after re-watering, being the slowest in outdoor summer plants and the fastest in indoor plants. It is suggested that these differences among the experiments are related to the prevailing climatic conditions, i.e. to the fact that stress factors other than water stress have been superimposed (e.g. excessive light and elevated temperature). In conclusion, besides g(s), g(m) contributes greatly to the limitation of photosynthesis during water stress and during

  20. Proximal Sensing of Plant-Pathogen Interactions in Spring Barley with Three Fluorescence Techniques

    Directory of Open Access Journals (Sweden)

    Georg Leufen

    2014-06-01

    Full Text Available In the last years fluorescence spectroscopy has come to be viewed as an essential approach in key research fields of applied plant sciences. However, the quantity and particularly the quality of information produced by different equipment might vary considerably. In this study we investigate the potential of three optical devices for the proximal sensing of plant-pathogen interactions in four genotypes of spring barley. For this purpose, the fluorescence lifetime, the image-resolved multispectral fluorescence and selected indices of a portable multiparametric fluorescence device were recorded at 3, 6, and 9 days after inoculation (dai from healthy leaves as well as from leaves inoculated with powdery mildew (Blumeria graminis or leaf rust (Puccinia hordei. Genotype-specific responses to pathogen infections were revealed already at 3 dai by higher fluorescence mean lifetimes in the spectral range from 410 to 560 nm in the less susceptible varieties. Noticeable pathogen-induced modifications were also revealed by the ‘Blue-to-Far-Red Fluorescence Ratio’ and the ‘Simple Fluorescence Ratio’. Particularly in the susceptible varieties the differences became more evident in the time-course of the experiment i.e., following the pathogen development. The relevance of the blue and green fluorescence to exploit the plant-pathogen interaction was demonstrated by the multispectral fluorescence imaging system. As shown, mildewed leaves were characterized by exceptionally high blue fluorescence, contrasting the values observed in rust inoculated leaves. Further, we confirm that the intensity of green fluorescence depends on the pathogen infection and the stage of disease development; this information might allow a differentiation of both diseases. Moreover, our results demonstrate that the detection area might influence the quality of the information, although it had a minor impact only in the current study. Finally, we highlight the relevance of

  1. Physiological responses of Brassica napus to fulvic acid under water stress: Chlorophyll a fluorescence and antioxidant enzyme activity

    Directory of Open Access Journals (Sweden)

    Ramin Lotfi

    2015-10-01

    Full Text Available The ameliorative effect of fulvic acid (0, 300, and 600 mg L− 1 on photosystem II and antioxidant enzyme activity of the rapeseed (Brassica napus L. plant under water stress (60, 100, and 140 mm evaporation from class A pan was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid (FA improved the maximum quantum efficiency of PSII (Fv/Fm and performance index (PI of plants under both well-watered and limited-water conditions. The time span from Fo to Fm and the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species (ROS is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.

  2. Water stress from high-volume hydraulic fracturing potentially threatens aquatic biodiversity and ecosystem services in Arkansas, United States

    Science.gov (United States)

    Entrekin, Sally; Trainor, Anne; Saiers, James; Patterson, Lauren; Maloney, Kelly O.; Fargione, Joseph; Kiesecker, Joseph M.; Baruch-Mordo, Sharon; Konschnik, Katherine E.; Wiseman, Hannah; Nicot, Jean-Philippe; Ryan, Joseph N.

    2018-01-01

    Demand for high-volume, short duration water withdrawals could create water stress to aquatic organisms in Fayetteville Shale streams sourced for hydraulic fracturing fluids. We estimated potential water stress using permitted water withdrawal volumes and actual water withdrawals compared to monthly median, low, and high streamflows. Risk for biological stress was considered at 20% of long-term median and 10% of high- and low-flow thresholds. Future well build-out projections estimated potential for continued stress. Most water was permitted from small, free-flowing streams and “frack” ponds (dammed streams). Permitted 12-h pumping volumes exceeded median streamflow at 50% of withdrawal sites in June, when flows were low. Daily water usage, from operator disclosures, compared to median streamflow showed possible water stress in 7–51% of catchments from June–November, respectively. If 100% of produced water was recycled, per-well water use declined by 25%, reducing threshold exceedance by 10%. Future water stress was predicted to occur in fewer catchments important for drinking water and species of conservation concern due to the decline in new well installations and increased use of recycled water. Accessible and precise withdrawal and streamflow data are critical moving forward to assess and mitigate water stress in streams that experience high-volume withdrawals.

  3. Water Stress from High-Volume Hydraulic Fracturing Potentially Threatens Aquatic Biodiversity and Ecosystem Services in Arkansas, United States.

    Science.gov (United States)

    Entrekin, Sally; Trainor, Anne; Saiers, James; Patterson, Lauren; Maloney, Kelly; Fargione, Joseph; Kiesecker, Joseph; Baruch-Mordo, Sharon; Konschnik, Katherine; Wiseman, Hannah; Nicot, Jean-Philippe; Ryan, Joseph N

    2018-02-20

    Demand for high-volume, short duration water withdrawals could create water stress to aquatic organisms in Fayetteville Shale streams sourced for hydraulic fracturing fluids. We estimated potential water stress using permitted water withdrawal volumes and actual water withdrawals compared to monthly median, low, and high streamflows. Risk for biological stress was considered at 20% of long-term median and 10% of high- and low-flow thresholds. Future well build-out projections estimated potential for continued stress. Most water was permitted from small, free-flowing streams and "frack" ponds (dammed streams). Permitted 12-h pumping volumes exceeded median streamflow at 50% of withdrawal sites in June, when flows were low. Daily water usage, from operator disclosures, compared to median streamflow showed possible water stress in 7-51% of catchments from June-November, respectively. If 100% of produced water was recycled, per-well water use declined by 25%, reducing threshold exceedance by 10%. Future water stress was predicted to occur in fewer catchments important for drinking water and species of conservation concern due to the decline in new well installations and increased use of recycled water. Accessible and precise withdrawal and streamflow data are critical moving forward to assess and mitigate water stress in streams that experience high-volume withdrawals.

  4. Photosynthetic response of an alpine plant, Rhododendron delavayi Franch, to water stress and recovery: the role of mesophyll conductance

    Directory of Open Access Journals (Sweden)

    Yanfei eCai

    2015-12-01

    Full Text Available Rhododendron delavayi Franch is an evergreen shrub or small tree with large scarlet flowers that makes it highly attractive as an ornamental species. The species is native to southwest China and southeast Asia, especially the Himalayan region, showing good adaptability and tolerance to drought. To understand the water stress coping mechanisms of R. delavayi, we analysed the plant’s photosynthetic performance during water stress and recovery. In particular, we looked at the regulation of stomatal (gs and mesophyll conductance (gm, and maximum rate of carboxylation (Vcmax. After four days of water stress treatment, the net CO2 assimilation rate (AN declined slightly while gs and gm were not affected and stomatal limitation (SL was therefore negligible. At this stage mesophyll conductance limitation (MCL and biochemical limitation (BL constituted the main limitation factors. After eight days of water stress treatment, AN, gs and gm had decreased notably. At this stage SL increased markedly and MCL even more so, while BL remained relatively constant. After re-watering, the recovery of AN, gs and gm was rapid, although remaining below the levels of the control plants, while Vcmax fully regained control levels after three days of re-watering. MCL remained the main limitation factor irrespective of the degree of photosynthetic recovery. In conclusion, in our experiment MCL was the main photosynthetic limitation factor of R. delavayi under water stress and during the recovery phase, with the regulation of gm probably being the result of interactions between the environment and leaf anatomical features.

  5. Nitrogen acquisition by pea and barley and the effect of their crop residues on available nitrogen for subsequent crops

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1996-01-01

    Nitrogen acquisition by field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) grown on a sandy loam soil and availability of N in three subsequent sequences of a cropping system were studied in an outdoor pot experiment. The effect of crop residues on the N availability was evaluated....... The dry matter production and total N uptake of a spring barley crop following pea or barley, with a period of unplanted soil in the autumn/winter, were significantly higher after pea than after barley. The barley crop following pea and barley recovered 11% of the pea and 8% of the barley residue N...

  6. PHYSIOLOGICAL AND AGROECOLOGICAL ASPECTS OF CADMIUM INTERACTIONS WITH BARLEY PLANTS: AN OVERVIEW

    Directory of Open Access Journals (Sweden)

    A VASSILEV

    2003-07-01

    Full Text Available This work is a review of author’s previous publications, unpublished results as well as available literature on barley responses to Cd contamination. The physiological backgrounds of the acute Cd toxicity in barley plants are briefly described. Some data characterizing the chronic Cd toxicity in barley have been also provided in relation to its possible use for seed production and Cd phytoextraction on Cd-contaminated agricultural soils. Information about the main physiological factors limiting growth of Cd-exposed barley plants and grain yield, seedling quality as well as Cd phytoextraction capacity of barley grown in Cd-contaminated soils is presented.

  7. Biotin Carboxyl Carrier Protein in Barley Chloroplast Membranes

    DEFF Research Database (Denmark)

    Kannangara, C. G.; Jense, C J

    1975-01-01

    Biotin localized in barley chloroplast lamellae is covalently bound to a single protein with an approximate molecular weight of 21000. It contains one mole of biotin per mole of protein and functions as a carboxyl carrier in the acetyl-CoA carboxylase reaction. The protein was obtained by solubil...... by solubilization of the lamellae in phenol/acetic acid/8 M urea. Feeding barley seedlings with [14C]-biotin revealed that the vitamin is not degraded into respiratory substrates by the plant, but is specifically incorporated into biotin carboxyl carrier protein....

  8. Analysis of Pregerminated Barley Using Hyperspectral Image Analysis

    DEFF Research Database (Denmark)

    Arngren, Morten; Hansen, Per Waaben; Eriksen, Birger

    2011-01-01

    imaging system in a mathematical modeling framework to identify pregerminated barley at an early stage of approximately 12 h of pregermination. Our model only assigns pregermination as the cause for a single kernel’s lack of germination and is unable to identify dormancy, kernel damage etc. The analysis...... is based on more than 750 Rosalina barley kernels being pregerminated at 8 different durations between 0 and 60 h based on the BRF method. Regerminating the kernels reveals a grouping of the pregerminated kernels into three categories: normal, delayed and limited germination. Our model employs a supervised...

  9. Effect of irradiation on the malting quality of barley

    International Nuclear Information System (INIS)

    Avtar, S.; Tejinder, S.; Bains, G.S.

    1985-01-01

    Two six-row barley cultivars, DL 70 and C164 were subjected to Co 60 gamma irradiation in the range of 0 to 250 Krad and malted with and without gibberellic acid treatment. Barley irradiated with doses up to 75 Krad produced normal malts when compared to the controls. Irradiation doses of 125 and 250 Krad significantly increased the malt yields but considerably decreased the α-amylase activity. Gibberellic acid significantly increased the enzyme activity and degree of modification of the irradiated and the control malts. (author)

  10. Identification and characterization of barley RNA-directed RNA polymerases

    DEFF Research Database (Denmark)

    Madsen, Christian Toft; Stephens, Jennifer; Hornyik, Csaba

    2009-01-01

    in dicot species. In this report, we identi!ed and characterized HvRDR1, HvRDR2 and HvRDR6 genes in the monocot plant barley (Hordeum vulgare). We analysed their expression under various biotic and abiotic stresses including fungal and viral infections, salicylic acid treatment as well as during plant...... development. The different classes and subclasses of barley RDRs displayed contrasting expression patterns during pathogen challenge and development suggesting their involvement in speci!c regulatory pathways. Their response to heat and salicylic acid treatment suggests a conserved pattern of expression...

  11. The experience of induction of mutation on barley in Peru

    International Nuclear Information System (INIS)

    Romero Loli, M.; Pozo Cardenas, M.; Gomez Pando, L.

    1984-01-01

    Work on induced mutation of barley was started in 1978 under the Programme of Cereal Improvement. Barley was irradiated with gamma radiation at doses of 12, 15, 18, 21, and 24 Krad. Radiation doses of 18 and 21 Krad gave the highest frequency of albino and cloroticos mutants. Induced mutation is being carried out in different parts of the country to develop mutants having early germination property. These mutants will play an important role in the late cultivation in the mountain areas of Peru

  12. Giemsa C-banding of Barley Chromosomes. IV. Chromosomal Constitution of Autotetraploid Barley

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib

    1984-01-01

    The progeny of an autotetraploid barley plant (C1) consisted of 45 tetraploids and 33 aneuploids. Giemsa C-banding was used to identify each of the chromosomes in 20 euploid and 31 aneuploid C2--seedlings, and in 11 C3--offspring of aneuploid C2--plants. The euploid C2--seedlings all had four...... homologues of each of the chromosomes. The aneuploid C2--seedlings were fairly equally distributed on hypo-and hyperploids, and on the seven chromosome groups. This suggests that a particular chromosome is lost or gained at random in gametes and embryos. The 11 C3--seedlings comprised seven true euploids......, one seedling with 2n=28 having an extra chromosome 6 and missing one chromosome 3, and three seedlings with 2n=29. The chromosomal composition of aneuploid C3--seedlings did not reflect that of their aneuploid C2--parents with respect to missing or extra chromosomes. Two hypohexaploid C2--seedlings...

  13. Climate change and the vulnerability of electricity generation to water stress in the European Union

    Science.gov (United States)

    Behrens, Paul; van Vliet, Michelle T. H.; Nanninga, Tijmen; Walsh, Brid; Rodrigues, João F. D.

    2017-08-01

    Thermoelectric generation requires large amounts of water for cooling. Recent warm periods have led to curtailments in generation, highlighting concerns about security of supply. Here we assess EU-wide climate impacts for 1,326 individual thermoelectric plants and 818 water basins in 2020 and 2030. We show that, despite policy goals and a decrease in electricity-related water withdrawal, the number of regions experiencing some reduction in power availability due to water stress rises from 47 basins to 54 basins between 2014 and 2030, with further plants planned for construction in stressed basins. We examine the reasons for these pressures by including water demand for other uses. The majority of vulnerable basins lie in the Mediterranean region, with further basins in France, Germany and Poland. We investigate four adaptations, finding that increased future seawater cooling eases some pressures. This highlights the need for an integrated, basin-level approach in energy and water policy.

  14. Infrared thermometry: a remote sensing technique for predicting yield in water-stressed cotton

    International Nuclear Information System (INIS)

    Pinter, P.J.; Fry, K.E.; Guinn, G.; Mauney, J.R.

    1983-01-01

    A crop water stress index (CWSI) was derived from air temperatures, air vapor pressure deficits and the midday radiant leaf temperatures of cotton plants that were exposed to different early-season irrigation treatments at Phoenix, AZ, U.S.A. To calculate the CWSI, an infrared thermometer was used to measure leaf temperatures which were then scaled relative to minimum and maximum temperatures expected for no-stress (CWSI=0) and extreme drought-stress conditions (CWSI=1). Results showed the CWSI behaved as expected, dropping to low levels following an irrigation and increasing gradually as the cotton plants depleted soil moisture reserves. The final yield of seed cotton was significantly inversely correlated with the average CWSI observed over the interval from the appearance of the first square until two weeks following the final irrigation

  15. Assessment of (Fouquieria splendens ssp. breviflora Cell Cultures Response Under to Water Stress

    Directory of Open Access Journals (Sweden)

    Leonor Angélica Guerrero Zúñiga

    2017-05-01

    Full Text Available Plant cell cultures are homogenous experimental systems, highly controllable that allow the study of short and large water stress adaptations without the interference of the different tissues and development of plants. An approach to understand these adaptations is through the presence of induced proteins; as a result of changes in genetic expression. This work analyze the response of Fouquieria splendens ssp. breviflora cell cultures exposed to abscisic acid (ABA, through the electrophoretic characterization of quantity and quality of stress induced proteins. There were recorded low molecular weight polypeptides (< 35kDa, common in experiments under ABA 10mM, followed by the association with 20 and 30mM ABA conditions, with a particularly response of cell cultures without the stress agent.

  16. Evaluation of Some Chemical Characteristics of barley Mutants induced by Gamma Irradiation

    International Nuclear Information System (INIS)

    Abdeldaiem, M.H.; Ali, H.G.M.

    2011-01-01

    This study aims to evaluate the antioxidant activity of acetonic extract from some barley mutations (P1, P2 and P3 varieties) induced by gamma irradiation as compared with local barley variety (Hordeum vulgare L.) as control. Barley samples were obtained from Plant Breeding Unit, Plant Research Department, Nuclear Research Centre, Atomic Energy Authority, Egypt. The measurements of the antioxidant activity using a radical scavenging capacity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ?-carotene bleaching assay were assessed in the barley acetonic extract. Furthermore, amino acids composition of barley mutant samples was determined. The results indicated that the acetonic extract of barley varieties under investigation possess marked antioxidant and anti radical capacities. The data showed that the acetonic extract of barley mutant P1 possessed the higher antioxidant activity as compared with the antioxidant activities of acetonic extract from control and other barley mutant samples. Meanwhile, the flour of barley mutations under investigation contained trace elements of iron, copper and manganese. GC and mass analyses were used to identify the active compound of extract of control and mutant barley samples. The results illustrated that the main components of the control sample of barely extract was pentane, 3 methyl (47.73%) while gamma irradiation caused noticeable change in the relative percentage of some components of acetonic extract from barley mutant samples. Moreover, the results presented that changes were disappeared, and some compounds of the acetonic extract from mutant barley samples were appeared. Furthermore, the results exhibited that barley flour supplemented with wheat flour at 30% level produced acceptable cookies. Accordingly, the phenolic constituents of barley acetonic extract induced by gamma irradiation, especially samples of P1 mutant, may have a future role as ingredients in the development of functional foods.

  17. Evaluate Effect of Water Stress and Different Amounts of Nitrogen Fertilizer on Seed Quality of Black Cumin (Nigella Sativa L

    Directory of Open Access Journals (Sweden)

    M Heidari

    2014-03-01

    Full Text Available In order to study the effects of water stress and different levels of nitrogen fertilizer on grian yield and accumulation macronutrients included: nitrogen, phosphorus and potassium and micronutrient included: iron, zinc, manganese and copper, oil, protein and thymoquinone contents in seed of black cumin, a field experiment was conducted as split plot design with three replications at Agricultural Research Station, Zahak, Zabol during growing season of 2010-2011. Water stress treatments included: W1= control, W2= no irrigation at stem elongation stage to flowering, W3= irrigation at flowering stage until the beginning of grain filling and W4= no irrigation at flowering and grain filling as the main plots and four levels of nitrogen application fertilizer, including N1= control or without any fertilizer consumption, N2= 30 kg N/ha, N3= 60 kg N/ha and N4= 90 kg N/ha in sub plot. Results showed that water stress had significant effect on the grain yield and accumulation of macro and micronutrient in the seed of Black Cumin. Except for and iron, the highest amounts of nitrogen, phosphorus, potassium, manganese, copper and zinc and the lowest amount of grain yield were obtained at W4 treatment and manganese at W3 treatment. In this experiment the interaction effect between stress and nitrogen fertilizer except grain yield and potassium had significant impact on others elements. The results indicated that water stress at flowering and grain filling (W4 stages, the maximum amount of micro and macronutrients in seed was obtained at N1 and N2 nitrogen treatment. Also, water stress and nitrogen treatments increased the percentage of protein, oil and thymoquinone contents of seed, but during the onset of water stress and the use of nitrogen fertilizer, the highest percentage of protein in and thymoquinone were obtained in W4N4.

  18. Crop yield response to water stress imposed at different growth stages

    International Nuclear Information System (INIS)

    Iqbal, M.; Mahmood Shah, M.; Wisal, M.

    1995-01-01

    Potato requires sufficient soil moisture and fertilization to produce high yields but the present water resoures are limited compared to the cultivable land, field experiments were conduced from 1991 to 1995 to study relationship between yield and crop water use as a function of water stress imposed at different growth stages. The irrigation treatments involved application of full and stress watering s selectively at four growth stages : Establishment , Flowering Tuber formation and ripening. In full watering, full water requirements of the crop were met, i.e., ET sub a = ET sub m whereas in stress watering about half the amount of full watering was applied, i.e., ET sub a < ET sub m. Changes in moisture content of the soil pre files after irrigation were monitored with the help of neutron moisture probe in order to compute ET sub a by the water balance method. The results obtained showed that the tuber yield was produced by full watering ( T 1) and the lowest by continuous stress watering (T 2). A plot of relative yield against relative evapotranspiration deficit revealed that ripening was the lest sensitive whereas early development followed by flowering the most sensitive growth stage to water stress. The crop water use efficiencies were generally higher in the treatments where a combination of normal and stress watering was applied compared to where all - normal watering s were applied. The traditional irrigation practice resulted in wasteful water application with relatively lower yields, hence the results from this project will have high value for the farming community to get this higher yields with scarce water resources. The studies with labelled fertilizer showed that planting and earthing - up were equally important growth stages of potato for applying fertilizer for its efficient utilization. 3 figs; 25 tabs; 12 refs (Author)

  19. Estimating a Global Hydrological Carrying Capacity Using GRACE Observed Water Stress

    Science.gov (United States)

    An, K.; Reager, J. T.; Famiglietti, J. S.

    2013-12-01

    Global population is expected to reach 9 billion people by the year 2050, causing increased demands for water and potential threats to human security. This study attempts to frame the overpopulation problem through a hydrological resources lens by hypothesizing that observed groundwater trends should be directly attributed to human water consumption. This study analyzes the relationships between available blue water, population, and cropland area on a global scale. Using satellite data from NASA's Gravity Recovery and Climate Experiment (GRACE) along with land surface model data from the Global Land Data Assimilation System (GLDAS), a global groundwater depletion trend is isolated, the validity of which has been verified in many regional studies. By using the inherent distributions of these relationships, we estimate the regional populations that have exceeded their local hydrological carrying capacity. Globally, these populations sum to ~3.5 billion people that are living in presently water-stressed or potentially water-scarce regions, and we estimate total cropland is exceeding a sustainable threshold by about 80 million km^2. Key study areas such as the North China Plain, northwest India, and Mexico City were qualitatively chosen for further analysis of regional water resources and policies, based on our distributions of water stress. These case studies are used to verify the groundwater level changes seen in the GRACE trend . Tfor the many populous, arid regions of the world that have already begun to experience the strains of high water demand.he many populous, arid regions of the world have already begun to experience the strains of high water demand. It will take a global cooperative effort of improving domestic and agricultural use efficiency, and summoning a political will to prioritize environmental issues to adapt to a thirstier planet. Global Groundwater Depletion Trend (Mar 2003-Dec 2011)

  20. Increased transpiration and plant water stress in a black spruce bog exposed to whole ecosystem warming

    Science.gov (United States)

    Warren, J.; Ward, E. J.; Wullschleger, S. D.; Hanson, P. J.

    2017-12-01

    The Spruce and Peatland Responses under Changing Environments (SPRUCE) experiment (http://mnspruce.ornl.gov/) in Northern Minnesota, USA, has exposed 12.8 m diameter plots of an ombrotrophic Picea mariana-Ericaceous shrub bog to whole ecosystem warming (0, +2.25, +4.5, +6.75, +9 °C) since August 2015, and elevated CO2 treatments (ambient or +500 ppm) since June 2016. The mixed-age stand has trees up to 40 year old, and a 5-8 m tall canopy. Thermal dissipation sap flow probes were installed into dominant Picea mariana and Larix laricina trees in each of the 10 open-top chambers in fall 2015. This talk will focus on the first two years of sap flux data from the 10 treatment plots and the relationships with seasonal growth and prevailing environmental conditions. Sap flow was scaled to whole tree and plot level transpiration based on prior in situ calibrations using cut trees, establishment of a sapwood depth: tree diameter relationship, and the tree size distribution within each plot. We also assessed water potential in the trees and two dominant shrubs at the site: Rhododendron groenlandicum and Chamaedaphne calyculata. The warming treatments increased the growing season by up to 6 weeks, with sapflow beginning earlier in spring and lasting later into the fall. The deciduous Larix was the only species exhibiting substantial predawn water stress under the treatments, where water potentials reached -2.5 MPa for the warmest plots. The elevated CO2 reduced midday water stress in the Rhododendron, but not the Chamaedaphne, which could lead to shifts in shrub species composition.

  1. Germination and vigor of linseed seeds under different conditions of light, temperature and water stress

    Directory of Open Access Journals (Sweden)

    Raquel Stefanello

    2017-06-01

    Full Text Available Linseed (Linum usitatissimum L., cultivated from seeds, is one of the oldest plants domesticated by humans and is popularly used as a medicine. It can be used as the raw material to produce oil and bran because it has high lipids content, fiber and proteins. Based on the economic potential of this species and the need for more information about its physiology, the goal of this study was to analyze the effects of light, temperature and water stress on the germination and vigor of linseed seeds. In experiment I the seeds were sown on paper at constant temperatures of 15, 20, 25 and 30 ºC in the presence and absence of light. In experiment II, the seeds were placed on paper germitest soaked in solutions of polyethylene glycol (PEG 6000 at osmotic potentials corresponding to zero, -0.10, -0.20, -0.30, -0.40, -0.50 and -0.60 MPa. To evaluate the physiological potential, the following tests were made: germination, first germination count, length and dry mass of seedlings, and water stress. It was found that the highest percentages of germination and vigor occurred at a constant temperature of 20 °C, both in the presence and absence of light. The reduction of the osmotic potential of the substrate promoted a significant decrease in the germination and vigor of the linseed seeds. Osmotic potentials equal or less than -0.30 MPa were harmful to germination and there was no normal seedling development starting at -0.50 MPa.

  2. 14CO2-assimilation, translocation of 14C, and 14C-carbonate uptake in different organs of spring barley plants in relation to adult-plant resistance to powdery mildew

    International Nuclear Information System (INIS)

    Hwang, B.K.; Ibenthal, W.-D.; Heitefuss, R.

    1986-01-01

    The cultivar Peruvian of spring barley, which is susceptible at all growth stages, and Asse, which exhibits adult-plant resistance to powdery mildew, were compared in 14 CO 2 assimilation, distribution of 14 C, and 14 C-carbonate uptake in different organs of healthy and infected plants. The reduction of 14 CO 2 assimilation in infected plants at the first and fourth leaf stages was greater in Peruvian than in Asse. In Peruvian, the 14 C which was fixed by the infected third leaf of plants with mildew on the lower 3 leaves remained in the third leaves with very little translocation to other parts of the plant. Infection of the lower three leaves at the fourth leaf stage reduced 14 CO 2 assimilation in noninfected fourth leaves of Asse less than that of Peruvian, but the flow of 14 C from the healthy fourth leaves into other plant parts such as leaf sheaths was markedly stimulated in Peruvian compared to Asse. Infection also reduced the uptake of 14 C-carbonate by seedling roots, the reduction being greater in Peruvian than Asse. A greater proportion of the 14 C absorbed by roots of Asse was translocated to the infected leaves than that of Peruvian. It was concluded that powdery mildew disrupted the normal pattern of photosynthesis and translocation of metabolites in a susceptible cultivar more markedly than in an adult-plant-resistant cultivar of spring barley. (author)

  3. Falling for Clay Leaves.

    Science.gov (United States)

    Kernan, Christine

    2002-01-01

    Describes an art project that integrated science and art education. Explains that students create ceramic bowls by using real leaves. Discusses the process of creating the ceramic bowls, including how to glaze the bowls. Includes a list of materials. (CMK)

  4. The Impact of Phaeomoniella chlamydospora Infection on the Grapevine's Physiological Response to Water Stress - Part 2 : Cabernet Sauvignon and Chardonnay

    Directory of Open Access Journals (Sweden)

    J. Edwards

    2007-04-01

    Full Text Available Phaeomoniella chlamydospora is a vascular pathogen that colonises the xylem tissues of the grapevine. It is associated with the diseases, esca and Petri disease, often considered to be ‘stress-related’ diseases. In glasshouse experiments using Cabernet Sauvignon and Chardonnay, stomatal conductance was higher in infected plants, implying that infection interferes with stomatal control. In Cabernet Sauvignon, leaf water potentials were lower in infected plants subjected to water stress, indicating that infection made it more difficult for the vine to get water to the leaf. This was less apparent in Chardonnay. Clearly, infection alters the grapevine response to water stress and some cultivars are affected more than others.

  5. Ultraviolet-B and water stress effects on growth, gas exchange and oxidative stress in sunflower plants.

    Science.gov (United States)

    Cechin, Inês; Corniani, Natália; de Fátima Fumis, Terezinha; Cataneo, Ana Catarina

    2008-07-01

    The effects and interaction of drought and UV-B radiation were studied in sunflower plants (Helianthus annuus L. var. Catissol-01), growing in a greenhouse under natural photoperiod conditions. The plants received approximately 1.7 W m(-2) (controls) or 8.6 W m(-2) (+UV-B) of UV-B radiation for 7 h per day. The UV-B and water stress treatments started 18 days after sowing. After a period of 12 days of stress, half of the water-stressed plants (including both UV-B irradiated or non-irradiated) were rehydrated. Both drought and UV-B radiation treatments resulted in lower shoot dry matter per plant, but there was no significant interaction between the two treatments. Water stress and UV-B radiation reduced photosynthesis, stomatal conductance and transpiration. However, the amplitude of the effects of both stressors was dependent on the interactions. This resulted in alleviation of the negative effect of drought on photosynthesis and transpiration by UV-B radiation as the water stress intensified. Intercelluar CO(2) concentration was initially reduced in all treatments compared to control plants but it increased with time. Photosynthetic pigments were not affected by UV-B radiation. Water stress reduced photosynthetic pigments only under high UV-B radiation. The decrease was more accentuated for chlorophyll a than for chlorophyll b. As a measure for the maximum efficiency of photosystem II in darkness F (v)/F (m) was used, which was not affected by drought stress but initially reduced by UV-B radiation. Independent of water supply, UV-B radiation increased the activity of pirogalol peroxidase and did not increase the level of malondialdehyde. On the other hand, water stress did not alter the activity of pirogalol peroxidase and caused membrane damage as assessed by lipid peroxidation. The application of UV-B radiation together with drought seemed to have a protective effect by lowering the intensity of lipid peroxidation caused by water stress. The content of proline

  6. The Effect of Vermicompost and Mycorrhizal Inoculation on Grain Yield and some Physiological Characteristics of Soybean (Glycine max L. under Water Stress Condition

    Directory of Open Access Journals (Sweden)

    Elham Jahangiri nia

    2017-08-01

    Full Text Available Introduction Moisture limitation is considered as one of the important limiting factors in soybean growth. Drought stress affects different aspects of soybean growth through making anatomical, physiological and biochemical changes (Tarumingkeng & Coto, 2003. Under dry tension condition, there will be a disturbance in transmitting nutrients, but some useful soil fungi such as mycorrhiza improve production of crops under stress through forming colonies in the root and boosting water and nutrient absorption (Al-Karaki et al., 2004. Using vermicompost in sustainable agriculture strengthens support and activities of beneficial soil microorganisms (such as mycorrhizal fungi and phosphate solubilizing microorganisms in order to provide nutrients required by plants like nitrogen, phosphorus and soluble potassium as well as improving the growth and performance of the crops (Arancon et al., 2004. Materials and methods In order to investigate the effects of vermicompost and mycorrhiza fertilizers on grain yield and some physiological characteristics of soybean under water stress condition an experiment was conducted at Agricultural Research Center of Khorramabad during 2013. The field experiment was carried out based on a randomized complete blocks design arranged in split-plot with four replications. The experiment treatments including irrigation in three levels (after 60, 120 and 180 mm evaporation from pan class A pan, nutrient management in six levels (non-use of vermicompost and mycorhiza fertilizer, inoculated with mycorrhiza fertilizer, consumption of 5 and 10 t.ha-1 vermicompost, consumption of 5 and 10 t.ha-1 vermicompost with mycorrhiza were respectively as the main plots and sub. In current study, RWC, LAI, SPAD were measured during 59 days after planting at the beginning of podding of the control treatment. The temperature of plant leaves were measured by the thermometer (model TM-958 LUTRON infrared Thermometers. To analyze the growth of

  7. Maternity Leave Policies

    Science.gov (United States)

    Strang, Lucy; Broeks, Miriam

    2017-01-01

    Abstract Over recent years many European Union countries have made changes to the design of the maternity leave provision. These policy developments reflect calls for greater gender equality in the workforce and more equal share of childcare responsibilities. However, while research shows that long period of leave can have negative effects on women's labour market attachment and career advancements, early return to work can be seen as a factor preventing exclusive breastfeeding, and therefore, potentially having negative health impacts for babies. Indeed, the World Health Organisation recommends exclusive breastfeeding up to 6 months of age to provide babies with the nutrition for healthy growth and brain development, protection from life-threatening ailments, obesity and non-communicable diseases such as asthma and diabetes. Therefore, labour market demands on women may be at odds with the health benefits for children gained by longer periods of maternity leave. The aim of this article is to examine the relationship between leave provision and health benefits for children. We examine maternity and parental leave provision across European countries and its potential impact on the breastfeeding of very young babies (up to 6-months of age). We also consider economic factors of potential extension of maternity leave provision to 6 months, such as costs to businesses, effects on the female labour market attachment, and wider consequences (benefits and costs) for individuals, families, employers and the wider society. PMID:28983432

  8. Changes of Root Hydraulic Conductivity and Root/Shoot Ratio of Durum Wheat and Barley in Relation to Nitrogen Availability and Mercury Exposure

    Directory of Open Access Journals (Sweden)

    Giovanna Angelino

    2011-02-01

    Full Text Available The aim of this research was to verify, on whole plant level and during all the plant cycle, the hypothesis that nitrogen deficiency reduces root hydraulic conductivity through the water channels (aquaporins activity, and that the plant reacts by changing root/shoot ratio. Root hydraulic conductivity, plant growth, root/shoot ratio and plant water status were assessed for durum wheat (Triticum durum Desf. and barley (Hordeum vulgare L., as influenced by nitrogen availability and HgCl2 treatment. On both species during the plant cycle, nitrogen deficiency induced lower root hydraulic conductivity (-49 and -66% respectively for barley and wheat and lower plant growth. On wheat was also observed cycle delay, lower plant nitrogen content, but not lower leaf turgor pressure and epidermic cell dimension. The lower plant growth was due to lower plant dimension and lower tillering. Root /shoot ratio was always higher for nitrogen stressed plants, whether on dry matter or on surface basis. This was due to lower effect of nitrogen stress on root growth than on shoot growth. On wheat HgCl2 treatment determined lower plant growth, and more than nitrogen stress, cycle delay and higher root/shoot ratio. The mercury, also, induced leaf rolling, lower turgor pressure, lower NAR, higher root cell wall lignification and lower epidermic cell number per surface unity. In nitrogen fertilized plants root hydraulic conductivity was always reduced by HgCl2 treatment (-61 and 38%, respectively for wheat and barley, but in nitrogen unfertilized plants this effect was observed only during the first plant stages. This effect was higher during shooting and caryopsis formation, lower during tillering. It is concluded that barley and durum wheat react to nitrogen deficiency and HgCl2 treatment by increasing the root/shoot ratio, to compensate water stress due to lower water root conductivity probably induced by lower aquaporin synthesis or inactivation. However, this

  9. Changes of Root Hydraulic Conductivity and Root/Shoot Ratio of Durum Wheat and Barley in Relation to Nitrogen Availability and Mercury Exposure

    Directory of Open Access Journals (Sweden)

    Celestino Ruggiero

    2007-09-01

    Full Text Available The aim of this research was to verify, on whole plant level and during all the plant cycle, the hypothesis that nitrogen deficiency reduces root hydraulic conductivity through the water channels (aquaporins activity, and that the plant reacts by changing root/shoot ratio. Root hydraulic conductivity, plant growth, root/shoot ratio and plant water status were assessed for durum wheat (Triticum durum Desf. and barley (Hordeum vulgare L., as influenced by nitrogen availability and HgCl2 treatment. On both species during the plant cycle, nitrogen deficiency induced lower root hydraulic conductivity (-49 and -66% respectively for barley and wheat and lower plant growth. On wheat was also observed cycle delay, lower plant nitrogen content, but not lower leaf turgor pressure and epidermic cell dimension. The lower plant growth was due to lower plant dimension and lower tillering. Root /shoot ratio was always higher for nitrogen stressed plants, whether on dry matter or on surface basis. This was due to lower effect of nitrogen stress on root growth than on shoot growth. On wheat HgCl2 treatment determined lower plant growth, and more than nitrogen stress, cycle delay and higher root/shoot ratio. The mercury, also, induced leaf rolling, lower turgor pressure, lower NAR, higher root cell wall lignification and lower epidermic cell number per surface unity. In nitrogen fertilized plants root hydraulic conductivity was always reduced by HgCl2 treatment (-61 and 38%, respectively for wheat and barley, but in nitrogen unfertilized plants this effect was observed only during the first plant stages. This effect was higher during shooting and caryopsis formation, lower during tillering. It is concluded that barley and durum wheat react to nitrogen deficiency and HgCl2 treatment by increasing the root/shoot ratio, to compensate water stress due to lower water root conductivity probably induced by lower aquaporin synthesis or inactivation. However, this

  10. (QTLs) for γ- aminobutyric acid content in grain of barley

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... protein content, while Schooner is a hull two-rowed cultivar malting barley with low ... being kept at 20°C for 4~8 min, the mixture was heated in a boiling water bath for ..... John Wiley & Sons, Inc. Hobokwen, New Jersey. Nie C ...

  11. Hydrothermal liquefaction of barley straw to bio-crude oil

    DEFF Research Database (Denmark)

    Zhu, Zhe; Rosendahl, Lasse; Toor, Saqib

    2015-01-01

    Hydrothermal liquefaction (HTL) of barley straw with K2CO3 at different temperatures (280–400 C) was conducted and compared to optimize its process conditions; the aqueous phase as a co-product from this process was recycled to explore the feasibility of implementing wastewater reuse for bio...

  12. Variation in In Vitro Digestibility of Barley Protein

    DEFF Research Database (Denmark)

    Buchmann, N. B.

    1979-01-01

    impaired digestibilities; these findings were partially verified in a repeated field trial, but were not confirmed in vivo. In vitro digestibilities of barleys grown in pots at various N-levels were positively correlated with protein or hordein content. In vitro digestibility was negatively correlated...

  13. The Mutation Frequency in Different Spike Categories in Barley

    DEFF Research Database (Denmark)

    Frydenberg, O.; Doll, Hans; Sandfær, J.

    1964-01-01

    After gamma irradiation of barley seeds, a comparison has been made between the chlorophyll-mutant frequencies in X1 spikes that had multicellular bud meristems in the seeds at the time of treatment (denoted as pre-formed spikes) and X1 spikes having no recognizable meristems at the time...

  14. Wheat and barley exposure to nanoceria: Implications for agricultural productivity

    Science.gov (United States)

    The impacts of man-made nanomaterials on agricultural productivity are not yet well understood. A soil microcosm study was performed to assess the physiological, phenological, and yield responses of wheat (Triticum aestivum) and barley (Hordeum vulgare L.) exposed to nanoceria (n...

  15. 108-110 Registration of Guta Barley (Hordeium vulgare L.)

    African Journals Online (AJOL)

    adoption potential by the local farmers. Keywords: Guta; Barley (Hordeium vulgare L); Yield ... evaluated along with Aruso and Shage as the local and standard variety, respectively at altitudinal range of 2400- ... 6. Farmers Evaluation of the Variety. To evaluate the perception and preferences of the local farmers, farmers' ...

  16. Aspects of the barley seed proteome during development and germination

    DEFF Research Database (Denmark)

    Finnie, Christine; Maeda, K.; Østergaard, O.

    2004-01-01

    Analysis of the water-soluble barley seed proteome has led to the identification of proteins by MS in the major spots on two-dimensional gels covering the pi ranges 4-7 and 6-11. This provides the basis for in-depth studies of proteome changes during seed development and germination, tissue...

  17. The proteomic analysis of barley albumins and globulins

    Czech Academy of Sciences Publication Activity Database

    Laštovičková, Markéta; Bobálová, Janette

    2008-01-01

    Roč. 102, č. 15 (2008), s709-s711 ISSN 1803-2389. [Meeting on Chemistry and Life /4./. Brno, 09.09.2008-11.09.2008] R&D Projects: GA MŠk 1M0570 Institutional research plan: CEZ:AV0Z40310501 Keywords : barley * albumins * globulins Subject RIV: CB - Analytical Chemistry, Separation

  18. Wheat and barley seed systems in Ethiopia and Syria

    NARCIS (Netherlands)

    Bishaw, Z.

    2004-01-01

    Keywords: Wheat,Triticumspp., Barley,Hordeumvulgare L., Seed Systems, Formal Seed Sector, Informal Seed Sector, National Seed Program, Seed Source, Seed Selection, Seed Management, Seed Quality,

  19. The Role of alpha-Glucosidase in Germinating Barley Grains

    DEFF Research Database (Denmark)

    Stanley, Duncan; Rejzek, Martin; Næsted, Henrik

    2011-01-01

    The importance of alpha-glucosidase in the endosperm starch metabolism of barley (Hordeum vulgare) seedlings is poorly understood. The enzyme converts maltose to glucose (Glc), but in vitro studies indicate that it can also attack starch granules. To discover its role in vivo, we took complementa...

  20. Spatial aggregation of pathotypes of barley powdery mildew

    DEFF Research Database (Denmark)

    O'Hara, R.B.; Brown, J.K.M.

    1997-01-01

    Aggregation in the distribution of pathotypes of Erysiphe graminis f.sp. hordei, the barley powdery mildew pathogen, was investigated in field plots of 'Golden Promise', 'Proctor' and 'Tyra'. 'Golden Promise' and 'Proctor' have no effective mildew resistance alleles, whereas 'Tyra' has Mla1, which...

  1. Two barley yellow dwarf luteovirus serotypes associated with ...

    African Journals Online (AJOL)

    Barley yellow dwarf luteovirus (BYDV) serotypes PAV and RPV were identified from irrigated wheat (Triticum aestivum L.) samples from three provinces of Zambia by double antibody sandwich enzyme-linked immunosorbent assay using polyclonal and monoclonal antisera. Nine wheat cultivars were surveyed in 11 wheat ...

  2. Evaluation of genetic diversity in barley ( Hordeum vulgare L.) from ...

    African Journals Online (AJOL)

    This study aimed to determine the genetic diversity and relationships among barley varieties (Hordeum vulgare L.) growing at Wollo Highland areas by using hordein and agro-morphological traits. Twenty (20) varieties were laid down in randomized complete block design (RCBD) design with three replications; they were ...

  3. Genetic diversity in barley landraces (Hordeum vulgare L. subsp.

    Indian Academy of Sciences (India)

    Genetic diversity in barley landraces (Hordeum vulgare L. subsp. vulgare) originated from Crescent Fertile region as detected by seed storage proteins. RIM MZID FARHAT CHIBANI RAYDA BEN AYED MOHSEN HANANA JOELLE BREIDI RABIH KABALAN SAMIH EL-HAJJ HASSAN MACHLAB AHMED REBAI LAMIS ...

  4. Genetic analysis on the competitive ability of barley ( Hordeum ...

    African Journals Online (AJOL)

    Genetic analysis on the competitive ability of barley ( Hordeum vulgare L.) recombinant inbred lines intercropped with oat ( Avena sativa L.) weeds. ... Furthermore, the commonly used herbicide price is soaring from time to time and out of the reach of the poor farmers in the developing countries. Therefore, this method is an ...

  5. Transcriptome of barley under three different heavy metal stress reaction

    Czech Academy of Sciences Publication Activity Database

    Kintlová, Martina; Blavet, Nicolas; Cegan, R.; Hobza, Roman

    2017-01-01

    Roč. 13, SEP (2017), s. 15-17 ISSN 2213-5960 R&D Projects: GA ČR GBP501/12/G090 Institutional support: RVO:61389030 Keywords : plants * Barley * RNA-Seq * Transcriptome * Heavy metal * Copper * Zinc * Cadmium Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany

  6. A weed suppressive index for spring barley (Hordeum vulgare) varieties

    DEFF Research Database (Denmark)

    Hansen, P K; Kristensen, K; Willas, J

    2008-01-01

    A screening programme for crop variety competitiveness would ideally be based on only a few, non-destructive measurements of key growth traits. In this study we measured the weed suppressive ability of 79 varieties of spring barley in two ways: (i) directly, by weed coverage assessments under wee...

  7. Zinc biofortification of cereals: rice differs from wheat and barley

    NARCIS (Netherlands)

    Stomph, T.J.; Jiang, W.; Struik, P.C.

    2009-01-01

    In their review, mainly focused on bread wheat (Triticum aestivum), durum wheat (Triticum durum) and barley (Hordeum vulgare), Palmgren et al. 1 M.G. Palmgren et al., Zinc biofortification of cereals: problems and solutions, Trends Plant Sci. 13 (2008), pp. 464–473. Article | PDF (905 K) | View

  8. Synthesis of the major storage protein, hordein, in barley

    DEFF Research Database (Denmark)

    Giese, Nanna Henriette; Andersen, B.; Doll, Hans

    1983-01-01

    A liquid culture system for culturing detached spikes of barley (Hordeum vulgare L.) at different nutritional levels was established. The synthesis of hordein polypeptides was studied by pulse-labeling with [14C]sucrose at different stages of development and nitrogen (N) nutrition. All polypeptides...

  9. Diversity in Indian barley (Hordeum vulgare) cultivars and ...

    Indian Academy of Sciences (India)

    tinguish varieties of crop plants and establish their purity as a prerequisite for any ... of genetic material in germplasm collection and as a general guide for the choice ... Sixty-nine barley cultivars were grown under field condi- tions in three ...

  10. Wheat and barley differently affect porcine intestinal microbiota

    DEFF Research Database (Denmark)

    Weiss, Eva; Aumiller, Tobias; Spindler, Hanns K

    2016-01-01

    Diet influences the porcine intestinal microbial ecosystem. Barrows were fitted with ileal T-cannulas to compare short-term effects of eight different wheat or barley genotypes and period-to-period effects on seven bacterial groups in ileal digesta and faeces by qPCR. Within genotypes of wheat an...

  11. Leaf rust of cultivated barley: pathology and control.

    Science.gov (United States)

    Park, Robert F; Golegaonkar, Prashant G; Derevnina, Lida; Sandhu, Karanjeet S; Karaoglu, Haydar; Elmansour, Huda M; Dracatos, Peter M; Singh, Davinder

    2015-01-01

    Leaf rust of barley is caused by the macrocyclic, heteroecious rust pathogen Puccinia hordei, with aecia reported from selected species of the genera Ornithogalum, Leopoldia, and Dipcadi, and uredinia and telia occurring on Hordeum vulgare, H. vulgare ssp. spontaneum, Hordeum bulbosum, and Hordeum murinum, on which distinct parasitic specialization occurs. Although Puccinia hordei is sporadic in its occurrence, it is probably the most common and widely distributed rust disease of barley. Leaf rust has increased in importance in recent decades in temperate barley-growing regions, presumably because of more intensive agricultural practices. Although total crop loss does not occur, under epidemic conditions yield reductions of up to 62% have been reported in susceptible varieties. Leaf rust is primarily controlled by the use of resistant cultivars, and, to date, 21 seedling resistance genes and two adult plant resistance (APR) genes have been identified. Virulence has been detected for most seedling resistance genes but is unknown for the APR genes Rph20 and Rph23. Other potentially new sources of APR have been reported, and additivity has been described for some of these resistances. Approaches to achieving durable resistance to leaf rust in barley are discussed.

  12. Registration of Food Barley (Hordeum vulgare L.) Variety HB 1307 ...

    African Journals Online (AJOL)

    Six-rowed food type barley, HB 1307, was developed by Holetta Agricultural Research Center (HARC) from a cross between a landrace line and exotic germplasm (Awra gebs-1 x IBON93/91) and released in 2006 for mid and high altitude areas. The three consecutive years\\' (2002-2004) tests proved its superiority in grain ...

  13. Classification and salt tolerance analysis of barley varieties

    NARCIS (Netherlands)

    Katerji, N.; Hoorn, van J.W.; Hamdy, A.; Mastrorilli, M.; Fares, C.; Ceccarelli, S.; Grando, S.; Oweis, T.

    2006-01-01

    Six varieties of barley (Hordeum vulgare), five of which were provided by ICARDA, were tested in a green house experiment for their salt tolerance. Afterwards the ICARDA variety Melusine, selected from this experiment for its combination of high yield and salt tolerance, was compared in a lysimeter

  14. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Science.gov (United States)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  15. Effect of water stress on seedling growth in two species with different abundances: the importance of Stress Resistance Syndrome in seasonally dry tropical forest

    Directory of Open Access Journals (Sweden)

    Wanessa Nepomuceno Ferreira

    2015-09-01

    Full Text Available ABSTRACTIn seasonally dry tropical forests, species carrying attributes of Stress Resistance Syndrome (SRS may have ecological advantages over species demanding high quantities of resources. In such forests, Poincianella bracteosa is abundant, while Libidibia ferrea has low abundance; therefore, we hypothesized that P. bracteosa has characteristics of low-resource species, while L. ferrea has characteristics of high-resource species. To test this hypothesis, we assessed morphological and physiological traits of seedlings of these species under different water regimes (100%, 70%, 40%, and 10% field capacity over 85 days. For most of the studied variables we observed significant decreases with increasing water stress, and these reductions were greater in L. ferrea. As expected, L. ferreamaximized their growth with increased water supply, while P. bracteosa maintained slower growth and had minor adjustments in biomass allocation, characteristics representative of low-resource species that are less sensitive to stress. We observed that specific leaf area, biomass allocation to roots, and root/shoot ratio were higher in L. ferrea, while biomass allocation to leaves and photosynthesis were higher in P. bracteosa. Results suggest that the attributes of SRS can facilitate high abundance of P. bracteosa in dry forest.

  16. Transcriptome analysis of trichothecene-induced gene expression in barley.

    Science.gov (United States)

    Boddu, Jayanand; Cho, Seungho; Muehlbauer, Gary J

    2007-11-01

    Fusarium head blight, caused primarily by Fusarium graminearum, is a major disease problem on barley (Hordeum vulgare L.). Trichothecene mycotoxins produced by the fungus during infection increase the aggressiveness of the fungus and promote infection in wheat (Triticum aestivum L.). Loss-of-function mutations in the TRI5 gene in F. graminearum result in the inability to synthesize trichothecenes and in reduced virulence on wheat. We examined the impact of pathogen-derived trichothecenes on virulence and the transcriptional differences in barley spikes infected with a trichothecene-producing wild-type strain and a loss-of-function tri5 trichothecene nonproducing mutant. Disease severity, fungal biomass, and floret necrosis and bleaching were reduced in spikes inoculated with the tri5 mutant strain compared with the wild-type strain, indicating that the inability to synthesize trichothecenes results in reduced virulence in barley. We detected 63 transcripts that were induced during trichothecene accumulation, including genes encoding putative trichothecene detoxification and transport proteins, ubiquitination-related proteins, programmed cell death-related proteins, transcription factors, and cytochrome P450s. We also detected 414 gene transcripts that were designated as basal defense response genes largely independent of trichothecene accumulation. Our results show that barley exhibits a specific response to trichothecene accumulation that can be separated from the basal defense response. We propose that barley responds to trichothecene accumulation by inducing at least two general responses. One response is the induction of genes encoding trichothecene detoxification and transport activities that may reduce the impact of trichothecenes. The other response is to induce genes encoding proteins associated with ubiquitination and cell death which may promote successful establishment of the disease.

  17. An ATP-binding cassette subfamily G full transporter is essential for the retention of leaf water in both wild barley and rice.

    Science.gov (United States)

    Chen, Guoxiong; Komatsuda, Takao; Ma, Jian Feng; Nawrath, Christiane; Pourkheirandish, Mohammad; Tagiri, Akemi; Hu, Yin-Gang; Sameri, Mohammad; Li, Xinrong; Zhao, Xin; Liu, Yubing; Li, Chao; Ma, Xiaoying; Wang, Aidong; Nair, Sudha; Wang, Ning; Miyao, Akio; Sakuma, Shun; Yamaji, Naoki; Zheng, Xiuting; Nevo, Eviatar

    2011-07-26

    Land plants have developed a cuticle preventing uncontrolled water loss. Here we report that an ATP-binding cassette (ABC) subfamily G (ABCG) full transporter is required for leaf water conservation in both wild barley and rice. A spontaneous mutation, eibi1.b, in wild barley has a low capacity to retain leaf water, a phenotype associated with reduced cutin deposition and a thin cuticle. Map-based cloning revealed that Eibi1 encodes an HvABCG31 full transporter. The gene was highly expressed in the elongation zone of a growing leaf (the site of cutin synthesis), and its gene product also was localized in developing, but not in mature tissue. A de novo wild barley mutant named "eibi1.c," along with two transposon insertion lines of rice mutated in the ortholog of HvABCG31 also were unable to restrict water loss from detached leaves. HvABCG31 is hypothesized to function as a transporter involved in cutin formation. Homologs of HvABCG31 were found in green algae, moss, and lycopods, indicating that this full transporter is highly conserved in the evolution of land plants.

  18. Allelopathic effects of barley straw on germination and seedling growth of corn, sugar beet and sunflower

    Directory of Open Access Journals (Sweden)

    mohamad taghi naseri poor yazdi

    2009-06-01

    Full Text Available Allelopathic effects of barley straw and root on germination and growth of maize, sugar beet, and sunflower were investigated under glasshouse and laboratory experiments in Faculty of Agriculture, Ferdowsi University of Mashhad in 2006. The glasshouse experiment was designed based on randomized complete block design with three replications, treatments included: 0, 200, 400, 600 g/m² of grounded barley straw and also 0 and 50 g/m2 barley root. A laboratory experiment was carried out in order to study the effect of different concentrations of barley water extracts on germination and seedling characteristics of corn, sugar beet and sunflower. Treatments in laboratory trial included 0, 33, 50 and 100 percent of barley extracts. Results showed that leaf area of corn was significantly affected by barley straw treatments. Shoot dry matter and seed weight per plant in corn , leaf and tuber weight in sugar beet and leaf , stem weights , plant per plant in corn , leaf and tuber weight in sugar beet and leaf, stem weights, plant height, head diameter, head weight and seed weight in sunflower were significantly higher in treatment of 50g/m² barley roots. Crop seed germination decreased with increasing the amount of barley straw. The best germination response to barley extract was observed in corn. Maize radicle weight was significantly decreased with increasing concentration of barley water extract.

  19. Amino acid transport across the tonoplast of vacuoles isolated from barley mesophyll protoplasts: Uptake of alanine, leucine, and glutamine

    International Nuclear Information System (INIS)

    Dietz, K.J.; Jaeger, R.; Kaiser, G.; Martinoia, E.

    1990-01-01

    Mesophyll protoplasts from leaves of well-fertilized barley (Hordeum vulgare L.) plants contained amino acids at concentrations as high as 120 millimoles per liter. With the exception of glutamic acid, which is predominantly localized in the cytoplasm, a major part of all other amino acids was contained inside the large central vacuole. Alanine, leucine, and glutamine are the dominant vacuolar amino acids in barley. Their transport into isolated vacuoles was studied using 14 C-labeled amino acids. Uptake was slow in the absence of ATP. A three- to sixfold stimulation of uptake was observed after addition of ATP or adenylyl imidodiphosphate an ATP analogue not being hydrolyzed by ATPases. Other nucleotides were ineffective in increasing the rate of uptake. ATP-Stimulated amino acid transport was not dependent on the transtonoplast pH or membrane potential. p-Chloromercuriphenylsulfonic acid and n-ethyl maleimide increased transport independently of ATP. Neutral amino acids such as valine or leucine effectively decreased the rate of alanine transport. Glutamine and glycine were less effective or not effective as competitive inhibitors of alanine transport. The results indicate the existence of a uniport translocator specific for neutral or basic amino acids that is under control of metabolic effectors

  20. Influence of arbuscular mycorrhizae on biomass production and nitrogen fixation of berseem clover plants subjected to water stress.

    Directory of Open Access Journals (Sweden)

    Sergio Saia

    Full Text Available Several studies, performed mainly in pots, have shown that arbuscular mycorrhizal symbiosis can mitigate the negative effects of water stress on plant growth. No information is available about the effects of arbuscular mycorrhizal symbiosis on berseem clover growth and nitrogen (N fixation under conditions of water shortage. A field experiment was conducted in a hilly area of inner Sicily, Italy, to determine whether symbiosis with AM fungi can mitigate the detrimental effects of drought stress (which in the Mediterranean often occurs during the late period of the growing season on forage yield and symbiotic N2 fixation of berseem clover. Soil was either left under water stress (i.e., rain-fed conditions or the crop was well-watered. Mycorrhization treatments consisted of inoculation of berseem clover seeds with arbuscular mycorrhizal spores or suppression of arbuscular mycorrhizal symbiosis by means of fungicide treatments. Nitrogen biological fixation was assessed using the 15N-isotope dilution technique. Arbuscular mycorrhizal symbiosis was able to mitigate the negative effect of water stress on berseem clover grown in a typical semiarid Mediterranean environment. In fact, under water stress conditions, arbuscular mycorrhizal symbiosis resulted in increases in total biomass, N content, and N fixation, whereas no effect of crop mycorrhization was observed in the well-watered treatment.