Nitrogen metabolism in Nicotian a rustica L. grown with molybdenum. I. vegetative development

Abstract

The effect of 1 ppm of molybdenum on nitrate reductase (EC 1.6.6.1.3) and nitrite reductase (EC 1.7.7.1) activity, and the nitrate, nitrite, ammonium, total nitrogen, total protein content on vegetative development of Nicotiana rustica L. was studied. This molybdenum supply increased the ammonium and nitrite content in leaves and the protein content in the root. Variations in enzymatic activity was not observed. The vegetative stage was shorter in the plants grown with this molybdenum supply.     

Activity of nitrate reductase and the content of proteins in Nicotiana rustica grown with various levels of molybdenum

The effect that different levels of molybdenum (11 μMand 111 μM) exert on nitrate reductase (E.C. 1.6.6.1–3) activity (NRA), and the content of total proteins in Nicotiana rustica was studied. Eleven μM and 111 μM of molybdenum increased the activity of nitrate reductase during the growth cycle of N. rustica. Likewise, total protein content (mg/g DW) was increased during the vegetative growth of the plants.     

In vitro digestibility and crude protein and mineral concentrations of guinea grass accessions in a humid tropical region of Puerto rico

Abstract

The in vitro organic matter digestibility (IVOMD), crude protein (CP) content and mineral composition of ten Panicum maximum accessions were compared between seasons in Puerto Rico and evaluated in relation to grazing ruminants requirements. On short days, PRPI 13605 was superior (P<0.05) in IVOMD to all the other accessions. In terms of the CP content, accession PRPI 3634 was above 11% in both seasons, however, without differing (P>0.05) from most accessions. The mean macroelement content of the accessions was generally adequate in relation to grazing ruminant requirements with the exception of Na and Mg. Phosphorus was less than the critical concentration (0.25%) for one‐half of the accessions in the short day season and 2 of 10 for the long day season. For all samples, Mn was high and Fe was generally adequate in relation to ruminant requirements. Most all samples contained deficient concentrations of Co, Cu, Se, and Zn. Forage Mo concentrations, therefore, did not result in conditioned Cu deficiencies. In this context, it is probable that Na, Se, Cu, Co, Zn, and perhaps Mg, will be needed even if intensive fertilization is practiced in the humid tropical region of Puerto Rico.     

Nitrogen nutrition of white rose potato in relation to vegetative growth and mineral content of leaves and roots

Abstract

White Rose potato plants were transplanted to nutrient solutions provided vith nine treatments of Ca(NO₃)₂ ranging from 0 to 64 mmoles per liter. Eighteen days later, symptoms of N‐deficiency ranging from very severe to none vere observed. The plants at this time were harvested, and leaves were sampled, oven dried, ground, and then analysed for K, Na, Ca, Mg, NO₃‐N, and acetic acid soluble H₂PO₂‐P.

Shoot and fibrous root growth increased with nitrate supply to an optimum, and then decreased with increased nitrate supply, suggesting nitrate toxicity due to the high nitrate supply of the nutrient solution. The nitrate content of the tissues increased with increased nitrate supply. Toxicity due to excess nitrate was associated with a very high nitrate content of the leaf tissues.

The critical NO₃‐N concentration at a 10% reduction in vegetative growth due to N‐deficiency is about 2000 ppm (0.2%) on a dry basis for the petioles and about 300 ppm (0.03%) for the blades of recently matured leaves.     

In Vitro digestibility,crude protein content,and mineral concentrations of cynodon,brachiarin, and digitaria accessions in a humid tropical region of Puerto Rico

Abstract

The in vitro organic matter digestibility (IVOMD), crude protein (CP) content, and mineral composition of 11 grasses were compared between seasons in Puerto Rico and evaluated in relation to grazing ruminant requirements. Digitaria eriantha was the highest in IVOMD for both seasons, being higher (P<0.05) than 6 of 10 forages in the long‐day season and 4 of 10 in the shortday season. No differences (P>0.05) in CP content were observed among accessions at both seasons. Mean macroelement content of the accessions was generally adequate in relation to grazing ruminant requirements with the exception of sodium (Na) and magnesium (Mg). Forage microelement concentrations of cobalt (Co), copper (Cu), and zinc (Zn) were generally under the grazing ruminant requirements for the accessions evaluated during both seasons. Iron (Fe) and manganese (Mn) content were high in relation to requirements, especially during the short‐day season. Molybdenum (Mo) was not in excess for the accessions evaluated. The Zn concentrations were similar to the results reported from other experiments with higher fertilization levels. The selenium (Se) concentrations presented an apparent seasonal variation higher in the short‐day season, which is similar to other experiments with high fertilization levels.     

Inter-relation between descriptors and morphine yield in Asian germplasm of opium poppy Papaver somniferum

A set of 208 Indian and two Thai germplasm accessions of opium poppy Papaver somniferum were assessed for variation in 17 morphological characters, seed yield and content and yield of morphine from capsules and peduncles. The germplasm was found to be highly variable for all the characters evaluated. In the harvested peduncles and capsules, 13% was peduncle straw, 61% seeds and the rest capsule husk. The peduncle and capsule straw yields ranged between 0.6–2.2 and 1.4–5.3 g plant^-1, respectively. Morphine content in the peduncle varied between about 0.001–0.24% and that in the capsule from 0.02 to 1.05%. On average basis morphine content in the capsule husk was more than 9-fold higher than the peduncle straw. The plant morphine yields from peduncles and capsules ranged between 1.2 and 28.6 mg plant^-1. Four accessions yielded more than 20 mg of morphine plant^-1. Among these, in one of the accessions about 13% of the morphine was contributed by the peduncle. The plants of high morphine yielding accessions were generally small in height, and bore white flowers and large sized ungrooved capsules with a small number of seeds, on a large peduncle.     

Contents of total protein, L-canavanine and condensed tannins of the one-flowered vetch (Vicia articulata Hornem.) collection of the Bank of Plant Germplasm of Cuenca (Spain)

A total of 125 accessions of one-flowered vetch (Vicia articulata Hornem.) mostly from the Iberian Peninsula have been analysed for total protein, L-canavanine and condensed tannins. It was observed a high variability in the composition: the protein content ranged from 18.20 to 30.07%, L-canavanine from 0.27 to 0.67%, and condensed tannins from 0.13 to 0.35%, which indicates a scarce domestication of the crop. The inclusion of the seeds into a diet to non-ruminants should be limited to marginal percentages because of the contents of L-canavanine and it suggests that a reduction of this compound by breeding should be encouraged. The protein and the L-canavanine contents showed a low and positive significant correlation (r = 0.55, P < 0.001), which complicates the selection of seeds having simultaneously low L-canavanine and high protein contents. On the other hand, no correlation between protein and condensed tannins or between L-canavanine and condensed tannins was observed. There was a poor relationship between the origin and the composition of the accessions and only the protein content was able to discriminate among the regions.     

Evaluation of European emmer wheat germplasm for agro-morphological,grain quality traits and molecular traits

A total of 38 emmer wheat accessions, collected in several European countries, have been evaluated using agro-morphological traits, grain quality characteristics and molecular markers. The agronomic traits evaluated were: vernalisation response, winter hardiness, date of heading and flowering, lodging, plant height at harvest and resistances against powdery mildew (Erysiphe graminis), leaf rust (Puccinia recondita) and yellow rust (Puccinia striiformis). Evaluation of quality traits has been performed measuring the protein content, gluten quality and quantity. In addition, a baking test has been executed. The assessment of genetic variability has been carried out at the molecular level utilizing 6 SSR, 6 EST-SSR markers for genes with known function, and 6 ISSR primers for a total of 107 loci analyzed. Mean 1,000 kernel weight ranged from 31.6 to 39.0 g for winter emmer accessions and from 22.9 to 42.6 for spring emmer accessions. The protein content for both winter and spring emmer was considerably affected by environment and genotype. Nearly, all the spring emmer accessions showed resistance to powdery mildew. Measurement of wet gluten content revealed high values, ranging from 37.0 to 56.6 %. The molecular analysis showed a great value of genetic distance between accessions; the expected heterozygosity and the variance between accessions indicate an equal distribution of the alleles (i.e. alleles frequency almost equal) and the presence of great variability in the analyzed material. Finally, no defined clusters were obtained considering winter versus spring accessions as well as the molecular markers did not discriminate the accessions respect their origin.     

Screening of barley landraces by direct selection for crop improvement

Abstract

Barley (Hordeum vulgare L.) landraces display a high degree of variability in morphological and developmental traits, in disease resistance, and in protein content. Representatives of 29 barley landraces from southeast Turkey were collected from farmers’ fields, for a total of 800 accessions. The objectives of this study were to characterize these accessions over four years for morphological and agronomical traits to be used for future selection and breeding program. The observed variation between landraces was very large for all traits. In the first year of testing the accessions showed average grain yields ranging from 197–2225 kg ha^?1. After three years of selection, promising accessions were tested at two different geographical regions and using two different irrigation methods. One line was identified which significantly out-yielded the local landrace in all of the testing years and had a higher average yield than the check genotypes.     

Effect of Daylength on the Nitrogen Status of Timothy (Phleum pratense L.)

Abstract

In two experiments timothy plants (Phleum pratense L., cultivars ‘Bodin’ and ‘Grindstad’, well established and vernalized in the first experiment and 7 weeks old in the second) were given daylength treatments with 12 h of photosynthetically active radiation (PAR) and day-lengthening light of low irradiance for from 2 to 13 weeks. Significant daylength effects on dry-matter, total nitrogen, nitrate and soluble protein content in the leaves of plants were demonstrated after only two weeks of treatment. The nitrogen and protein content decreased with increasing daylength, irrespective of the developmental stage of the plants. The dry-matter content increased with daylength when long days had induced generative development and decreased when all treatments at the same harvest were vegetative. The total nitrogen and protein per plant did not decrease from short to long days. The lower nitrogen and protein content in long days can therefore be regarded as a dilution caused by the increased dry-matter production found in these treatments. The observed effects of daylength on the ratio of assimilated nitrogen to assimilated carbon might be direct or indirect, since long days induce both enhanced dry-matter production and generative development in Bodin and Grindstad.     

Analysis of industrial effluents and their impact on the growth and metabolism of Phaseolus mungo,L.

Abstract

An analysis of dye and match industrial effluents revealed, that they are highly polluted. A study of the impact of these effluents on the growth and metabolism of Phaseolus mungo L., showed that percent germination and seedling length decreased with an increase in concentration of these effluents. There was a reduction in fresh weight and biomass accmulation (dry weight) that paralleled a decline in pigment content of the plant. This may be due to the degradation of chlorophyll caused by increased peroxidase activity. The soluble protein and in vivo nitrate reductase activity followed a declining trend, while the level of L‐proline showed an increasing trend with an increase in concentration of these effluents. The increase in leaf nitrate content at higher concentrations of effluents may be due to the high nitrate content in these effluents. Comparing these two industrial effluents, the effluent from the dye industry was found to be more toxic to the plant than that of the effluent from the match industry.     

Seed variability in <Emphasis Type="Italic">Madhuca longifolia</Emphasis> (Koenig) J. F. Macbride,a source of oil for use as bio-energy

Madhuca longifolia (Koenig) J. F. Macbride is native to India. Seeds contain 20–50% oil (Mahua oil) and the seed cake is used as manure. Mahua oil is used by rural communities for protection against storage pests. Almost all parts of this tree have medicinal properties. Four explorations and collection missions was conducted during July–October 2007 in Tamil Nadu and the Union Territory of Puducherry. This resulted in the collection of 55 accessions. Characterisation and analysis of 7 seed characters were done. The existence of enormous variability in seed length, thickness and 100 seed weight indicates scope for utilization of these accessions for selection of promising material for extraction of oil. Oil content of kernels has been evaluated. Kernel oil ranged from 44.43 to 61.50%. Three accessions IC556617 with 61.50, IC556632 with 60.80 and IC556632 with 60.55% of kernel oil are superior to the rest. Further collections in the site of these oil rich accessions are promising for more productive Madhuca longifolia genetic resources.     

Drought-tolerant naturalized populations of Lotus tenuis for constrained environments

Abstract

A perennial forage legume species tolerant to water stress would be useful to improve pasture and animal productivity in the central zone of Chile. The growth, dry-matter (DM) production, and drought tolerance of twelve accessions of Lotus tenuis Waldst & Kit, Syn. L. glaber, naturalized in Chile were evaluated with the objective to select contrasting genotypes, tolerant and sensitive to drought, for future breeding programmes. The accessions were sown in pots of 1.3 L containing a volcanic soil (Andisol). A completely randomized design with all combinations of Lotus accessions and four water treatments [100, 70, 40, and 10% of soil water availability (SWA)] was used. The relative rate of stem elongation (RRSE), the shoots and roots DM production, the relative water content (RWC), and the specific leaf area (SLA) were measured. A drought-sensitivity index (DSI) and the interaction genotype×environment were calculated. The RRSE, the DM production, RWC, and SLA all showed a significant reduction (P<0.05) in the treatment with the higher water restriction (10% SWA). There were significant differences (P<0.05) within RRSE and DM production genotype means, but the RWC and SLA did not differ among populations. The DSI varied broadly among genotypes, from 0.49 to 1.34, and was correlated negatively with DM production under water stress (10% SWA). It was concluded that the Lotus tenuis populations showed water-stress tolerance genetic variability, with accessions Lt14 and Lt4 the most contrasting. These findings will permit us to identify chromosomal regions associated with drought-tolerant genotypes which will allow us to accelerate the development of cultivars adapted to water-restricted environments.     

Evaluation of phenotypic variation in a worldwide germplasm collection of safflower (<Emphasis Type="Italic">Carthamus tinctorius</Emphasis> L.) grown under organic farming conditions in Germany

An investigation was conducted to determine the extent of diversity and relationships among a worldwide safflower (Carthamus tinctorius L.) germplasm collection and to find out adapted accessions that can be used in an organic safflower breeding program in Germany. A total of 468 accessions was studied under organic farming conditions at Kleinhohenheim experimental station during the seasons of 2004 and 2005. All the accessions were evaluated for 12 phenotypic traits and three rated diseases. Multivariate analyses have been used to measure the diversity in a subset of 200 accessions and 11 geographical regions. Generally, the study showed that there was a large genetic variation within accessions. A coefficient of variation (CV%) for investigated traits and diseases ranged from 2.9 to 91.0% with the highest CV was recorded for yield/m2, yield/plant and seeds/plant. The most accessions that originated in Europe revealed relatively better performance compared to non-Europeans. High yielding, early maturing, and disease tolerant accessions were identified. However, the low oil content (8.7–22.8%) is the primary concern in this germplasm collection. The degree of heritability varied between 10% for lodging to 86% for plant height. Genotypic coefficient of correlation (r _g) was slightly higher for many traits than the respective phenotypic coefficient. Oil content and seed yield/m2 were highly significantly correlated (r _g = 0.78). The genotypic coefficient of correlation showed that selection for seeds/plant and thousand kernel weight was effective for improvement of seed yield and oil content. The results of the principal component analysis and the clustering pattern of accessions were consistent with the results of analysis of variance. About 78% of the total phenotypic diversity in the germplasm was explained on the basis of four principal components and 88% of the total variation among geographical regions was contributed by the first three principal components. The distribution of the accessions within clusters has no apparent relationship with the geographical origin. However, many of the European accessions have a tendency to stay together.     

Growth and macronutrient contents of faba bean plants: Effects of salinity and nitrate nutrition

The effects of the interaction between sodium chloride, nitrate, and concentrations on growth and internal ion content of faba bean (Vicia faba L.) plants were studied, to understand the relationship between the above parameters and salt tolerance. Increased salinity substantially reduced the dry weight of roots and shoots and increased the root/shoot biomass ratio. Additional nitrate‐N considerably moderated the salinity effects on these parameters. The promotive effects of nitrate‐N were more pronounced on shoot dry weight. These results suggest that an exogenous supply of nitrate‐N would improve the vegetative growth of V. faba plants by moderating the suppresive effects of salinity. The evolution of the root and shoot content in potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), and nitrogen (N) was monitored during vegetative growth. A high correspondence between total N and Ca content was found. The acquisition of Ca and K in response to salt and nitrate was similar in shoots and roots, whereas Mg uptake showed notable differences in the two organs. In salt‐affected plants, the roots were found to be high in accumulated Na while the shoots exhibited the lowest Na concentration. Potassium accumulation was higher in the shoots. In this way, there was an antagonistic effect between Na and K uptake. Analyses of the nutrient contents in plant organs have provided a data base on salt‐tolerance mechanisms of V. faba plants.     

Tetraploid Wheat—A Resource for Genetic Improvement of Durum Wheat Quality

The tetraploid relatives (subspecies) of commercial durum wheat (Triticum turgidum L. subsp. turgidum conv. durum (Desf.) MacKey) offer a source of economically useful genes for the genetic improvement of durum cultivars. Tetraploid wheat subspecies show a wide diversity in grain protein composition and content, which are major factors determining the pasta-making quality of durum cultivars. In this study, the specific focus was the identification of accessions expressing one or more superior pasta-making traits. In all, 33 accessions were surveyed representing five different subspecies; var. durum (13 accessions), polonicum (7 accessions), persicum (3 accessions), turanicum (6 accessions), and turgidum (4 accessions). These accessions and the durum cultivars Wollaroi and Kamilaroi (in both years) and Yallaroi (in 1998 only) were grown at Tamworth, Australia in 1997 and 1998. Grain, semolina, and spaghetti cooking quality were evaluated using a range of tests. Several accessions were identified with larger grain size and protein content and higher semolina extraction. Although many of the accessions were weaker in dough strength, a few were equal to the commercial cultivars and produced pasta of comparable quality. The main disadvantage with these accessions was the low yellow color. These quality defects can be corrected by conventional breeding.     

The relation between growth and leaf nitrogen concentration in Nandi setaria and some other tropical grasses

Abstract

The relative growth rate of tops (RT) of Nandi setaria (Setaria anceps cv. Nandi), kikuyu (Pennisetum clandestinum). pangola (Digitaria decumbens) and Biloela buffel grass (Cenchrus ciliaris cv. Biloela) in pot experiments was a curvilinear function of the % N in the blades of the youngest fully‐expanded leaves on vegetative tillers (leaf N). The mean RT's differed significantly between grasses, but the response curves did not deviate significantly from being parallel. The mean quadratic curve for vegetative growth of Nandi setaria predicted increasing RT as leaf 11 rises from below 1 to about 3%, and near‐maximum RT between 3 and 6% N.     

Carbon decomposition kinetics and nitrogen mineralization from corn,soybean, and wheat residues

Abstract

An incubation study was conducted for 30 days in Taloka (fine, mixed, thermic mollic Albaqualf) and Leadvale (fine, silty, siliceous, thermic typic Fragiudult) silt loam soils to evaluate carbon (C) and nitrogen (N) mineralization from soybean [Glycine max (L.) Merr.], corn (Zea mays L.), and wheat (Triticum aestivum L.) residues. Corn and soybean residues were collected at the tasseling and late vegetative stages, respectively. Wheat straw was collected after harvest. Carbon dioxide (CO₂) evolution and inorganic N accumulation were measured. Carbon mineralization was described by a sequential decomposition model with a rapid and slow phase, each described by first‐order kinetics. Rapid and slow fraction rate constants and percent rapid were determined. Decomposition ranged from 39% for wheat to 67% for soybean. Carbon dioxide evolution peaked on the third day, and 30 to 50% of residue C was decomposed during the first six days of incubation. Decomposition and N mineralization were higher in the Taloka compared to the Leadvale soil, and generally followed the sequence soybean > corn > wheat residues as did percent rapid fraction, and rapid and slow fraction rate constants. Rapid fraction rate constants ranged from 0.039±0.005 to 0.115±0.005 per day. Slow fraction rate constants ranged from 0.013±0.002 to 0.030±0.002 per day. Percent rapid fraction ranged from 13±2% to 38±2%. The half‐lives of the slow fraction ranged from 23.4±3.5 to 51.8±3.5 days. Nitrogen mineralization, as estimated by ammonium (NH₄) and nitrate (NO₃) formation occurred only with the soybean residue, whereas the corn and wheat residues were characterized by N immobilization throughout the study.     

The genetic characterization of Turkish watermelon (<Emphasis Type="Italic">Citrullus lanatus</Emphasis>) accessions using RAPD markers

Genetic diversity of the Turkish watermelon genetic resources was evaluated using different Citrullus species, wild relatives, foreign landraces, open pollinated (OP) and commercial hybrid cultivars by RAPD markers. The germplasm was consisted of 303 accessions collected from various geographical regions. Twenty-two of 35 RAPD primers generated a total of 241 reproducible bands, 146 (60.6%) of which were polymorphic. Based on the RAPD data the genetic similarity coefficients were calculated and the dendrogram was constructed using UPGMA (Unweighted pair-group method with arithmetic average). Cluster analysis of the 303 accessions employing RAPD data resulted in a multi-branched dendrogram indicating that most of the Turkish accessions belonging to var. lanatus of Citrullus lanatus (Thunb.) Matsum et Nakai were grouped together. Accessions of different Citrullus species and Praecitrullus fistulosus (Stocks) Pangalo formed distant clusters from C. lanatus var. lanatus. Among 303 accessions, a subset of 56 accessions was selected representing different groups and a second dendrogram was constructed. The genetic similarity coefficients (GS) within the Turkish accessions were ranged from 0.76 to 1.00 with 0.94 average indicating that they are closely related. Taken together, our results indicated that low genetic variability exist among the watermelon genetic resources collected from Turkey contrary to their remarkable phenotypic diversity.