Genetic variability of mineral concentrations in Festuca arundinacea Schreb.

Summary Nine randomly chosen clones of tall fescue (Festuca arundinacea Schreb.) were mated in all possible combinations to determine the nature of genetic variation for Mg, Ca, K, and P concentrations in a broad genetic base population. General combining ability mean squares were significant for most variables, whereas specific combining ability mean squares were not significant in most instances indicating that additive genetic variance was more important. Genotype x year interactions were significant for most variables, suggesting that selection should be evaluated over many environments. Broad-sense heritability estimates based on parental and progeny variance components were generally high for P, K, Ca, and Mg but low for the ratio K/(Ca + Mg). Narrow-sense heritabilities for these minerals were close to the broad sense values since the additive genetic variance was the largest component of the total genetic variation. Correlations between mineral concentrations and herbage dry matter yield were low. It was concluded that adequate genetic variation exists to improve mineral concentration without altering herbage dry matter yields.Journal Series no. 5886     

Effects of the mineral composition and water content of intact plants on the fitness of the African armyworm

The effects of organic nitrogen, nitrate, phosphorus, potassium and water content of leaves of intact maize plants, grown in a gravel culture system, on the fitness of the African armyworm, Spodoptera exempta (Walker)(Lepidoptera: Noctuidae) were studied. Organic nitrogen concentrations ranged from 1.3% to 3.7% over four treatments differing only in nitrate supply to the plants. Water content and other mineral levels were all positively correlated with the organic nitrogen level. Feeding damage by the caterpillars was most severe on the lowest nitrate treatments, where it could be least well compensated for by new leaf growth. Larval and pupal fitness variables were not affected by treatment, except for larval development on the lowest nitrate treatment which was delayed by just 1 day. The large compensatory capacity of the larvae was underlined by a similar mineral composition of the pupae in all treatments. Adult fitness variables hardly differed between the upper three nitrate treatments, but revealed a trend over all treatments: the higher the organic nitrogen content of the leaves, the shorter the pre-oviposition period and the higher the fecundity. This trend, however, might have been due to differences in available food quantity rather than in food quality. It is concluded that fitness of the African armyworm is only slightly affected over a wide range of nitrogen concentrations in its food. Though effects might be larger under field conditions, the large differences in outbreak development between years seem not to be attributable to observed differences in nitrogen levels in host plants between years in primary outbreak areas. Other environmental factors appear to be of greater importance.     

Fertilization of poplar clones in the nursery

Summary Results of experiments with four poplar clones and various chemical fertilizers in a nursery in southern Greece are presented. At the end of the first growth period the heights of the four clones, without fertilizers, decreased in the order of I-214>I-262>cv. campeator > black poplar 1/64 with significant differences only between black poplar 1/64 and the rest of the clones.Of the fertilizer nutrients N, P, K and Mg only N improved heights of all clones significantly and especially of the clone I-214. One hundred and 200 kg of P fertilizer per ha had minimal or negative effect on height increase of all clones.Ammonium sulfate, ammonium nitrate and potassium nitrate all at 400 kg N per ha were found equally effective in improving height growth of the clone I-214 but ammonium nitrate is the N fertilizer of choice by its higher N content and relatively lower price.Ammonium nitrate at 200 kg N per ha, in two or three equal dosages, during the first growth period, June–July, gave the maximum height increase for two consecutive years of the clone I-214. Six hundred kgs, of N per ha reduced height increase of the same clone and increased losses of N, as NO₃ ^–, in drainage water.     

Monoterpene composition of cortical oleoresin from different clones of Pinus sylvestris

Monoterpene composition of cortical oleoresin was determined in a number of 9-yr-old grafts of Scots pine (Pinus sylvestris), growing in a clone trial at two different levels of mineral nutrient supply. Variation between clones was considerable for some of the monoterpene constituents, indicating genetic control. In one of the clones, δ³-carene, α-terpinene and terpinolene were totally absent. The monoterpene composition was not significantly affected by the annual application of macro-nutrients.     

Spatial variability of trace elements in fish otoliths: comparison with dietary items and habitat constituents in seagrass meadows

Juvenile trumpeters Pelates sexlineatus , two main prey items (amphipods and polychaetes) and seagrass constituents (detritus, young and old leaves of Zostera capricorni ) were collected from two sites within six estuaries, to compare the spatial variability of elemental composition (Li, Mn, Sr, Cd, Ba and Pb). Average elemental values were lower in the fish otoliths except for Sr. Significant differences in elemental composition of otoliths were detected among estuaries (Mn and Pb). Spatial differences in concentrations of Cd were found in amphipods and polychaetes; the latter also showed differences for Ba and Pb. Detritus and Z. capricorni leaves showed appreciable spatial differences for most of the elements. Spatial variability between sites was generally high. There were differences in the multivariate composition of trace elements found in the otoliths of fish among estuaries. One estuary was consistently separated from the other estuaries in the ordinations. Significant correlations were detected between concentrations of Mn in otoliths and concentrations in prey, Z. capricorni and detritus. A significant relationship was also detected between Pb in otoliths and detritus. There were significant correlations between concentrations of Mn, Sr and Ba in detritus and that in otoliths. The study demonstrated that trophic transfer and habitat constituents may be considered as a potential source for some of the elemental accumulation in fish otoliths.     

Changes in Mineral Content of Eucalyptus marginata and E. calophylla Grown under Controlled Conditions and Inoculated with Phytophthora cinnamomi

Mineral concentrations in infected roots and shoots were compared with similar material, but pathogen free, for the susceptible Eucalyptus marginata and the field resistant E. calophylla. All plants were mycorrhiza-free, grown under controlled conditions and inoculated with an axenic suspension of zoospores of Phytophthora cinnamomi. Plant material was ashed 30 days after inoculation and analyzed in an external proton beam using PIXE and nuclear reaction analyis to detect differences in mineral concentrations. The mineral content of infected roots of E. marginata was below that of the uninfected roots for all elements detected except chlorine, chromium and rubidium. The reductions were significant for calcium and copper. No such reduction was found, in E. calophylla roots, but some changes were detected. Shoot: root ratios of E. marginata showed significant differences associated with infection in phosphorus, calcium, copper and zinc. Relatively large differences were also recorded for sulphur chlorine and potassium. Shoot: root ratios of infected E. calophylla showed fewer differences but contained only half the concentrations of sulphur and potassium present in the controls. The reduced mineral concentrations reflect the failure in conduction of water and minerals through the infected and susceptible root system.     

Efficiency of nitrate uptake in spinach: impact of external nitrate concentration and relative growth rate on nitrate influx and efflux

Regulation of nitrate influx and efflux in spinach (Spinacia oleracea L., cv. Subito), was studied in short-term label experiments with 13N- and 15N-nitrate. Nitrate fluxes were examined in relation to the N demand for growth, defined as relative growth rate (RGR) times plant N concentration. Plants were grown at different nitrate concentrations (0.8 and 4 mM), with mineral composition of growth and uptake solutions identical. Nitrate influx, efflux and net nitrate uptake rate (NNUR) were independent of the external nitrate concentration, despite differences in internal nitrate concentration. At both N regimes, NNUR was adequate to meet the N demand for growth. RGR-related signals predominantly determined the nitrate fluxes. At high RGR (0.25 g g-1 day-1), nitrate influx was 20 to 40% lower and nitrate efflux was 50 to 70% lower than at lower RGR (0.17 g g-1 day-1); efflux:influx ratio (E:I) declined from 0.5 at low RGR to 0.2 at higher RGR. Thus, the efficiency of NNUR substantially increased with increasing RGR. Differences in nitrate translocation between morning and afternoon coincided with differences in nitrate efflux, which is in accordance with the suggested regulation of nitrate efflux by the root cytoplasmic nitrate concentration. This revised version was published online in July 2006 with corrections to the Cover Date.     

Gender Differences in Correlations Between the Content of Elements in Rain Water and the Frequency of Hospitalization for Arterial Hypertension, Chronic Obstructive Pulmonary Disease, and Psoriasis in Opole Voivodship, Poland, During 2000–2002

The aim of this work is to show and give a plausible explanation to gender-dependent differences in correlations between the content of selected elements in rainwater and the frequency of hospitalization by reason of arterial hypertension, chronic obstructive pulmonary disease (COPD), and psoriasis in the area of Opolskie Voivodeship, Poland, during the period 2000-2002. The elements analyzed were sodium, potassium, calcium, magnesium, manganese, iron, total phosphorus, total nitrogen, ammonium nitrogen, zinc, copper, lead, cadmium, nickel, chromium, chloride, nitrate, and sulfate. Hospitalization due to arterial hypertension was more frequent in women, whereas those for COPD and psoriasis were more frequent in men. In the case of women hospitalized for arterial hypertension, the correlations were low, except for zinc (r = 0.47) and for cadmium (r = 0.43). In men hospitalized for COPD, all of the correlation coefficients were higher than 0.4, except for phosphorus. The coefficients for nickel, ammonia nitrogen, and total nitrogen ranged from 0.5 to 0.6 and the remaining elements from 0.6 to 0.7. In women, the correlation was limited to five elements where the coefficient was r > 0.4 for chloride, calcium, nitrate, phosphorus, and chromium. In cases of hospitalization for psoriasis, the correlation in men was between 0.4 and 0.5 for chloride, phosphorus, copper, lead, and total nitrogen and greater than 5 for sulfate, potassium, calcium, iron, manganese, nitrate, and ammonium nitrogen. The correlation in women was between 0.48 and 0.5 for ammonium nitrogen and phosphorus.     

Ammonium inhibition of Arabidopsis root growth can be reversed by potassium and by auxin resistance mutations aux1, axr1, and axr2.

A novel effect of ammonium ions on root growth was investigated to understand how environmental signals affect organ development. Ammonium ions (3-12 mM) were found to dramatically inhibit Arabidopsis thaliana seedling root growth in the absence of potassium even if nitrate was present. This inhibition could be reversed by including in the growth medium low levels (20-100 microM) of potassium or alkali ions Rb+ and Cs+ but not alkali ions Na+ and Li+. The protective effect of low concentrations of potassium is not due to an inhibition of ammonium uptake. Ammonium inhibition is reversible, because root growth was restored in ammonium-treated seedlings if they were subsequently transferred to medium containing potassium. It is known that plant hormones can inhibit root growth. We found that mutants of Arabidopsis resistant to high levels of auxin and other hormones (aux1, axr1, and axr2) are also resistant to the ammonium inhibition and produce roots in the absence of potassium. Thus, the mechanisms that mediate the ammonium inhibition of root development are linked to hormone metabolic or signaling pathways. These findings have important implications for understanding how environmental signals, especially mineral nutrients, affect plant root development.     

Clonal variation in foliar chemistry of aspen: effects on gypsy moths and forest tent caterpillars

Quaking aspen (Populus tremuloides) exhibits striking intraspecific variation in concentrations of phenolic glycosides, compounds that play important roles in mediating interactions with herbivorous insects. This research was conducted to assess the contribution of genetic variation to overall phenotypic variation in aspen chemistry and interactions with gypsy moths (Lymantria dispar) and forest tent caterpillars (Malacosoma disstria). Thirteen aspen clones were propagated from field-collected root material. Insect performance assays, measuring survival, development, growth, and food utilization indices, were conducted with second and/or fourth instars. Leaf samples were assayed for water, nitrogen, total nonstructural carbohydrates, condensed tannins, and phenolic glycosides. Results showed substantial among-clone variation in the performance of both insect species. Chemical analyses revealed significant among-clone variation in all foliar constituents and that variation in allelochemical contents differed more than variation in primary metabolites. Regression analyses indicated that phenolic glycosides were the dominant factor responsible for among-clone variation in insect performance. We also found significant genetic trade-offs between growth and defense among aspen clones. Our results suggest that genetic factors are likely responsible for much of the tremendous phenotypic variation in secondary chemistry exhibited by aspen, and that the genetic structure of aspen populations may play important roles in the evolution of interactions with phytophagous insects. Received: 14 May 1996 / Accepted: 29 January 1997     

转TaLEA基因小黑杨无性系生长性状变异研究

以6年生的10个转TaLEA基因和1个非转基因小黑杨无性系为材料,对其生长量、干形、叶片性状、皮孔性状等15个指标进行测定分析。方差分析与遗传参数计算结果表明：11个小黑杨无性系间各性状达极显著差异水平（P＜0.01）,各指标表型变异系数处于1.92%~39.98%,遗传变异系数与表型变异系数接近,重复力处于0.621~0.987,表明基因的转入对无性系各性状的生长有一定的影响,但这种影响主要由遗传因素控制。表型相关分析结果表明转基因小黑杨生长量与干形性状、叶片性状、皮孔性状均呈不同程度的相关性,表明多指标共同作用,控制植株生长发育;利用综合评定法,当入选率为10%,初步选出XL-1和XL-9等2个优良无性系,2个无性系的树高、胸径分别比CK高16.55%和15.38%,比平均值高13.38%和19.46%,遗传增益分别为12.18%和17.42%。本研究为转基因杨树的良种选育提供重要的理论依据。     

ENVIRONMENTAL AND GENETIC CONSTRAINTS ON ADAPTIVE POPULATION DIFFERENTIATION IN ANTHOXANTHUM ODORATUM

Maximum-likelihood estimates of environmental and broad sense genetic (co)variance components were obtained for the growth and reproductive output of clones of the grass Anthoxanthum odoratum. The clones were transplanted between a mesic and a xeric field site and across-environment genetic correlations were used to estimate the strength of genotype-environment interaction. Significant across-environment clonal covariance matrices were found for several traits, including lifetime reproductive output in one population. None of the matrices differed significantly between populations. Significant within-site clonal variation was found, but there was no significant across-environment clonal covariation. Most broad sense heritability estimates of character states within sites were small (median = 0.12), suggesting that only a slow response to selection is possible. All significant within-site clonal correlations between growth and reproductive output were positive, although the pattern of negative clonal correlations suggests that there may be a cost to first year reproduction, which might constrain future selection response.     

The Uptake of Potassium, Nitrate, Water, and Oxygen by a Maize Root System in Relation to its Size

Using a special apparatus, the uptake of nitrate, potassium,water, and oxygen by a maize plant was recorded at short intervals.After cutting most of the roots, the regrowth of the root systemwas measured in relation to the increase in nitrate, potassium,and water uptake, oxygen consumption of the root system, andleaf growth rate. It has been suggested that when the root surfaceis not limiting nitrate reduction is the rate-limiting processfor nitrate uptake. Differences between nitrate uptake in lightand dark are explained by the influence of light on nitratereduction. Differences in leaf growth rate have been discussedin relation to root resistance and leaf water content.     

Cultivar differences in the rate of nitrate uptake by intact wheat plants as related to growth rate

Six Argentinian wheat ( Triticum aestivum L.) cultivars grown in nutrient solutions in controlled environment were compared for their nitrate uptake rates on a root dry weight basis. Up to 3-fold differences were observed among the cultivars at 16, 20 and 24 days from germination, either when measured by depletion from the nutrient solution in short-term experiments, or by total N accumulation in the tissue during 8 days.
No differences in total N concentration in root or shoots were found among cultivars. Although the different cultivars showed significant differences in shoot/root ratio and nitrate reductase activity (EC 1.6.6.1) in the roots, none of these parameters was correlated with the nitrate uptake rate. However, nitrate uptake was found to be positively correlated (r = 0.99) with the shoot relative growth rate of the cultivars. The three cultivars with the highest nitrate uptake rates and relative growth rates showed a positive correlation between root nitrate concentration and uptake. However, this correlation was not found in the cultivars with the lowest growth and uptake rates.
Our results indicate that the difference in nitrate uptake rate among these cultivars may only be a consequence of their differences in growth rate, and it is suggested that at least two mechanisms regulate nitrate uptake, one working when plant demand is low and another when plant demand is high.     

Subcellular Nutrient Element Localization and Enrichment in Ecto- and Arbuscular Mycorrhizas of Field-Grown Beech and Ash Trees Indicate Functional Differences

Mycorrhizas are the chief organ for plant mineral nutrient acquisition. In temperate, mixed forests, ash roots (Fraxinus excelsior) are colonized by arbuscular mycorrhizal fungi (AM) and beech roots (Fagus sylvatica) by ectomycorrhizal fungi (EcM). Knowledge on the functions of different mycorrhizal species that coexist in the same environment is scarce. The concentrations of nutrient elements in plant and fungal cells can inform on nutrient accessibility and interspecific differences of mycorrhizal life forms. Here, we hypothesized that mycorrhizal fungal species exhibit interspecific differences in mineral nutrient concentrations and that the differences correlate with the mineral nutrient concentrations of their associated root cells. Abundant mycorrhizal fungal species of mature beech and ash trees in a long-term undisturbed forest ecosystem were the EcM Lactarius subdulcis, Clavulina cristata and Cenococcum geophilum and the AM Glomus sp. Mineral nutrient subcellular localization and quantities of the mycorrhizas were analysed after non-aqueous sample preparation by electron dispersive X-ray transmission electron microscopy. Cenococcum geophilum contained the highest sulphur, Clavulina cristata the highest calcium levels, and Glomus, in which cations and P were generally high, exhibited the highest potassium levels. Lactarius subdulcis-associated root cells contained the highest phosphorus levels. The root cell concentrations of K, Mg and P were unrelated to those of the associated fungal structures, whereas S and Ca showed significant correlations between fungal and plant concentrations of those elements. Our results support profound interspecific differences for mineral nutrient acquisition among mycorrhizas formed by different fungal taxa. The lack of correlation between some plant and fungal nutrient element concentrations may reflect different retention of mineral nutrients in the fungal part of the symbiosis. High mineral concentrations, especially of potassium, in Glomus sp. suggest that the well-known influence of tree species on chemical soil properties may be related to their mycorrhizal associates.     

Free amino Acid contents of stem and phylloxera gall tissue cultures of grape

Free amino acid constituents were determined of grape stem and Phylloxera leaf gall callus in tissue culture. Fast, medium and slow growing single cell clones of, respectively, stem and gall origins were grown on a mineral salt-sucrose medium supplemented with coconut milk and α-naphthaleneacetic acid. Stem and gall clones showed qualitative similarities and quantitative variations in the amino acids and nitrogenous constituents. Nineteen amino acids, glucosamine, ethanolamine, sarcosine, methionine sulfoxides and ammonia were identified. Two free polypeptides accounted for over 30% of the amino compounds in the stem and gall callus tissues which were not found in the intact plant parts. Stem clones of different growth rates grown on agar showed generally an excess of amino acid constituents over gall tissues of similar growth rates, except for the free polypeptides. Fast growing stem clones grown on agar medium contained lower amounts of certain amino acids than the fast growing gall clones, but when grown in liquid medium they contained higher amounts of these acids than the gall clones. The total and nonsoluble nitrogen of stem clones were higher than in the gall clones. Tissue cultures differed from the original plant parts with respect to their free polypeptides and high amino acid contents.     

Correlation Analysis Between Bone Mineral Density and Serum Element Contents of Postmenopausal Women in Xi’an Urban Area

The objective of this paper is to investigate the correlation between serum macro-element and trace element contents and bone mineral density (BMD) as well as the occurrence of osteoporosis. After the epidemiological investigation of 290 postmenopausal women from ages 45 to 65 in the Xi’an urban area, their blood was collected and serum concentrations of macro-elements, calcium, phosphonium, potassium, sodium, magnesium, and trace elements, zinc, iron, copper, and selenium were determined using atomic absorption spectrometry. Their BMD was measured by QDR-2000 dual-energy X-ray absorptiometry (DEXA). The correlation analysis between BMD and serum element contents was done with the software of SPSS 13.0. The correlation analysis of serum elements of postmenopausal women showed that there was a significant correlation between serum calcium and the other elements, and also a significant correlation between serum phosphonium and the others except serum potassium. The serum potassium content had a significant correlation with serum calcium, sodium and iron, but sodium content showed a significant correlation with the others except iron and selenium. In addition, copper had a significant correlation with the others except potassium and selenium. In correlation analysis between BMD and the elements contents, only did the potassium content show a significant positive correlation with BMD of lumbar vertebra and proximal femora. The comparison results between osteoporosis group, osteopenia group, and healthy group showed that there was no significant difference in the element contents between the groups, but there existed a tendency that potassium content increased with the rise of BMD. There exist significant correlations between the contents of serum elements such as calcium, phosphonium, sodium, potassium, magnesium, zinc, iron, copper, and selenium, but no significant differences in these elements contents between the osteoporosis group, osteopenia group, and healthy group. Serum potassium content shows a significant positive correlation with BMD, suggesting potassium may be involved in the development of osteoporosis in postmenopausal women.     

Root excision decreases nutrient absorption and gas fluxes

The roots of barley plants (Hordeum vulgare L. cv Steptoe) were monitored before and after excision for net uptake of carbon dioxide, oxygen, ammonium, potassium, nitrate, and chloride and for their content of sucrose, glucose, fructose, and malic acid. All fluxes began to attenuate within 2 hours after excision. Net potassium uptake returned to control levels 6 hours after excision, but carbon dioxide, oxygen, ammonium, and nitrate fluxes continued to diminish for the remainder of the observation period. The addition of 0.1 molar glucose or 0.1 molar sucrose to excision medium had no significant effect on these changes in ion and gas fluxes. Net chloride uptake was negligible for all treatments. Sugar and malic acid content of the root declined after excision. Sucrose and glucose levels remained depressed for the entire observation period, whereas fructose and malic acid returned to control levels after 9 hours. These results indicate that excision has profound, adverse effects on root respiration and the absorption of mineral nitrogen.     

Accumulation of nitrate in the shoot acts as a signal to regulate shoot-root allocation in tobacco†

Mutants and transformants of tobacco (Nicotiania tabacum L. cv Gatersleben 1) with decreased expression of nitrate reductase have been used to investigate whether nitrate accumulation in the shoot acts as a signal to alter allocation between shoot and root growth. (a) Transformants with very low (1–3% of wild-type levels) nitrate reductase activity had growth rates, and protein, amino acid and glutamine levels similar to or slightly lower than a nitrate-limited wild-type, but accumulated large amounts of nitrate. These plants should resemble a nitrate-limited wild-type, except in responses where nitrate acts as a signal. (b) Whereas the shoot:root ratio decreases from about 3.5 in a well-fertilized wild-type to about 2 in a nitrate-limited wild-type, the transformants had a very high shoot:root ratio (8–10) when they were grown on high nitrate. When they were grown on lower nitrate concentrations their shoot:root ratio declined progressively to a value similar to that in nitrate-limited wild-types. Mutants with a moderate (30–50%) decrease of nitrate reductase also had a small but highly significant increase of their shoot:root ratio, compared to the wild-type. The increased shoot:root ratio in the mutants and transformants was due to a stimulation of shoot growth and an inhibition of root growth. (c) There was a highly significant correlation between leaf nitrate content and the shoot:root ratio for eight genotypes growing at a wide range of nitrate supply. (d) A similar increase of the shoot:root ratio in nitrate reductase-deficient plants, and correlation between leaf nitrate content and the shoot:root ratio, was found in plants growing on ammonium nitrate. (f) Split-root experiments, in which the transformants were grown with part of their root system in high nitrate and the other part in low nitrate, showed that root growth is inhibited by the accumulation of nitrate in the shoot. High concentrations of nitrate in the rooting medium actually stimulate local root growth. (g) The inhibition of root growth in the transformants was relieved when the transformants were grown on limiting phosphate, even though the nitrate content of the root remained high. This shows that the nitrate-dependent changes in allocation can be overridden by other signals that increase allocation to root growth. (h) The reasons for the changed allocation were investigated in transformants growing normally, and in split-root culture. Accumulation of nitrate in the shoot did not lead to decreased levels of amino acids or protein in the roots. However, it did lead to a strong inhibition of starch synthesis and turnover in the leaves, and to decreased levels of sugars in the root. The rate of root growth was correlated with the root sugar content. It is concluded that these changes of carbon allocation could contribute to the changes in shoot and root growth.     

响应面设计法优化单葡萄糖醛酸基甘草次酸（GAMG）发酵转化培养基

以甘草酸（dycyfrhizin,GL）为底物,利用产紫青霉（Penicillium purpurogenum Li-3）液态发酵转化单葡萄糖醛酸甘草次酸（GAMG）,采用响应面设计法对初始发酵培养基进行优化。用部分因子分析法研究原始发酵培养基各成分对响应值的显著程度,发现甘草酸（GL）、NaNO3和K2HPO4的质量浓度对发酵产生GAMG的影响显著（P〈0．01）。用中心组合设计确立甘草酸、NaNO3和K2HPO4的适宜质量浓度分别为2．8、3．0和0．8g／L。在优化条件下进行发酵时,GAMG的转化率从75．49％提高到89．11％,比优化前提高了13．62％。