Dry matter,nitrogen and phosphorus accumulation,partitioning and remobilization as affected by N and P fertilization and source–sink relations

Durum wheat (Triticum turgidum subsp. durum L.) is being increasingly grown in many areas of the world, but there is a lack of information about the physiological processes limiting grain yield. In this study, different rates of N and P fertilization were applied and the source:sink ratio was manipulated to examine the factor(s) limiting grain filling under rainfed conditions. Plants exposed to four fertilization treatments (control, 80 kg N ha^?1 (N), 50 kg P ha^?1 (P) and 80 kg N ha^?1 and 50 kg P ha^?1 (N–P)) and were artificially modified to obtain a range of different source:sink ratios. The treatments were (I) control; (II) half of the spike was removed; (III) all the spike was removed. The cultivar Cosmodur was used, which is widely grown in Greece and other Mediterranean countries and is quite productive especially under rainfed conditions. The distribution of dry matter, N and P among grains, stems and leaves was analyzed at anthesis and harvesting. Dry matter accumulation and partitioning into different plant parts was different between the fertilization treatments and the control. At anthesis, leaf + culm dry matter was higher than the chaff dry matter. Total aboveground biomass increased after anthesis in both years and at all fertilization treatments. N fertilization affected N concentration at the whole plant level at anthesis and at maturity. There was an average increase of 20% in N concentration with N application at anthesis in both years relative to the control. N content was affected by the fertilization treatments and it was increased by 33% over the 2 years of the study compared with the control. In addition, P fertilization affected P concentration both at anthesis and maturity in every plant organ, and there was also a significant effect of the change of P concentration at the two different growth stages. P accumulation was also affected by the fertilization regime and by the spike halving treatment. Dry matter translocation was an average of 22% higher at the fertilized treatments compared with the control, which indicates that fertilization led plants to translocate higher amount of dry matter. N and P translocation were affected by the fertilization treatment and in some treatments by the sink reduction. The spike reduction treatment increased the pre-anthesis contribution to seed indicating that the N and P remobilization from vegetative tissues were very important for grain development. The present study indicates that N and P fertilization and sink size can affect dry matter, N, and P accumulation, partitioning, and retranslocation of durum wheat which can affect seed yield.     

A wheat–Thinopyrum ponticum–rye trigeneric germplasm line with resistance to powdery mildew and stripe rust

An individual plant, line 0-123-1-1 with the chromosome number 2n?=?42 was obtained in the BC₃F₄ progeny of a cross between a wheat 1BL.1RS translocation line 48112 and wheat?CThinopyrum ponticum partial amphiploid BE-1. Molecular markers specific for 1RS, Glu-B3, and the T. ponticum genome specific marker SCAR₉₈₂ revealed that the line was trigeneric having alien chromatin from both T. ponticum and rye. Resistance tests with mixed races of Blumeria graminis f. sp. tritici and an individual race of Puccinia striiformis at the seedling and adult stages revealed that 0-123-1-1 was immune to powdery mildew and stripe rust for the whole growth period. High levels of disease resistance and good and stably agronomic traits make the 0-123-1-1 line a good germplasm for breeding in wheat.     

Dry matter yield,nitrogen content,and competition in pea–cereal intercropping systems

Intercrops of pea (Pisum arvense L.), a popular legume used in intercropping systems with winter cereals for forage and silage production, with wheat (Triticum aestivum L.), rye (Secale cereale L.), and triticale (× Triticosecale Wittmack) in two seeding ratios (60:40 and 80:20) were compared with monocrops of pea and cereals for two growing seasons. Growth rate, dry matter yield, and N uptake were determined in each intercropping system. Furthermore, several indices were used to evaluate the intercropping systems and analyze the competition and the interrelationships between mixture components. Growth rate of cereals was lower in the mixtures than in the monocrops. Dry matter yield was higher in triticale monocrop, followed by its two intercrops, and the pea–wheat 80:20 intercrop. Moreover, triticale monocrop, pea–triticale intercrops, and pea–wheat 80:20 intercrop showed the highest crude protein yield and N uptake. The land equivalent ratio (LER), relative crowding coefficient (K), actual yield loss (AYL), and system productivity index (SPI) values were greater for the pea–triticale mixtures and the pea–wheat and pea–rye mixtures (80:20), indicating an advantage of intercropping. In most intercrops, the values of partial K, AYL, aggressivity, and competitive ratio (CR) indicated that the cereal was more competitive than pea. The highest values of monetary advantage index (MAI) and intercropping advantage (IA) were recorded for the pea–triticale and the pea–wheat mixtures (80:20). Overall, pea–triticale and pea–wheat mixtures (80:20) were more productive and produced better forage quality than the other mixtures and thus could be adopted by the farmers as alternative options for forage production.     

Comparison and development of EST–SSRs from two 454 sequencing libraries of Gossypium barbadense

EST–SSRs of Gossypium barbadense are mainly developed using traditional Sanger sequencing. However, due to the high cost and low throughput of Sanger sequencing, it is necessary to use high throughput sequencing technology for the development of more ESTs to more effectively analyze the structure and function of this species. In this study, a G. barbadense acc. 3–79 unnormalized fiber cDNA library (219.63 Mb) and a G. barbadense cv. Hai7124 normalized root cDNA library (204.61 Mb) were obtained by 454 sequencing. EST–SSRs were identified from the two libraries, and only 7,255 SSRs were obtained from the unnormalized library, with an average frequency of 1/31.00 kb. In contrast, 16,087 SSRs were obtained from the normalized library, with an average frequency of 1/13.02 kb. The frequencies of dinucleotides and tetranucleotides in the two libraries were very different. Comparing the two libraries, we found that a normalized cDNA library is more efficient for mining SSRs. Integrating the two libraries allowed the development of 1,129 EST–SSR markers, and 311 polymorphic loci were integrated into our interspecific BC₁ genetic linkage map. The mapping results showed that the distribution of EST–SSRs on sub-genomes and chromosomes was uneven; however, the distribution of the mapped G. barbadense EST–SSRs on homologous chromosomes was similar, with the exception of Chr05 versus Chr19 and Chr12 versus Chr26. This study provided new EST–SSR markers that will facilitate studies on cotton genetics and breeding.     

Rice–weed competition in response to nitrogen form under high and low transpirational demand

Implementation of water-saving irrigation practices in lowland rice results in increased availability of nitrate (NO₃⁻) in the soil and favours germination of upland weeds. Since plant species show a specific preference for either ammonium (NH₄⁺) or NO₃⁻ as nitrogen (N) source, changes in both soil NO₃⁻ concentration and weed flora may affect the competition between rice and weeds. Further, the transpirational demand of the atmosphere might affect growth and competitiveness of lowland (wetland) and upland (dryland) weeds differently due to their adaptation to different ecological environments. Therefore, the study aimed to evaluate the effects of N source on growth, N uptake and competition between rice and common upland and lowland weeds under high and low vapour pressure deficit (VPD). Two rice (Oryza sativa) varieties (NU838 and KD18) differing in growth characteristics and two weed species (Echinochloa crus-galli and Solanum nigrum) differing in their natural habitat were selected and grown hydroponically as monoculture or mixed culture at low or high VPD. N was supplied as 75%/25% or 25%/75% NH₄⁺/NO₃⁻. N uptake rates were measured in the first week, whereas dry matter (DM), N concentration in the plant, total N uptake and the activities of nitrate reductase and glutamine synthetase in the fresh leaves were determined two weeks after the onset of treatments. Independent of N source, both rice varieties and E. crus-galli took up a larger share of NH₄⁺, whereas S. nigrum took up a larger share of NO₃⁻. N uptake of rice and E. crus-galli was hardly affected by N source, whereas high NO₃⁻ led to significantly higher N uptake rates and total N uptake of S. nigrum. NU838 showed a higher competitiveness against weeds than KD18. In competition, high NO₃⁻ decreased the competitiveness of E. crus-galli against NU838 but increased the competitiveness of S. nigrum against NU838. High VPD did not affect DM but increased N uptake of S. nigrum, leading to increased competitiveness of the weed at high transpirational demand. Competitiveness for N uptake appears to be an important trait as the relative N concentration in mixed plant communities was correlated with the activity of N-assimilating enzymes and leaf growth, with a stronger response in rice than in weeds. Our results support the hypothesis that increased availability of NO₃⁻ in aerobic rice soils may be advantageous for the competitiveness of upland weeds, especially at high VPD, whereas it may be disadvantageous for common lowland weeds.     

No-tillage and direct seeding for super hybrid rice production in rice–oilseed rape cropping system

No-tillage and direct seeding (NTDS) is an effective crop production method for reducing production costs and soil conservation. In order to understand performance of super hybrid rice under NTDS in rice–oilseed rape cropping system, a researcher-managed trail (2004–2010) and an on-farm research (2002–2005) were conducted to compare different tillage (conventional tillage or no-tillage) and rice establishment methods (transplanting or direct seeding) in super hybrid rice–oilseed rape cropping system. Under researcher-managed condition, grain yields of super hybrid rice under NTDS and conventional tillage and transplanting (CTTP) were equal. Compared with under CTTP, super hybrid rice under NTDS was characterized by more panicle number per m² but less spikelet number per panicle, and lower aboveground biomass production before heading but higher aboveground biomass accumulated during heading to maturity. Higher maximum tiller number per m² and lower spikelet production efficiency were responsible for the more panicle number per m² and less spikelet number per panicle under NTDS, respectively. Under farmer-managed condition, super hybrid rice under NTDS had more panicle number m² than under CTTP, which resulted in higher grain yield. Labor input under NTDS was lower than that under CTTP. Moreover, adoption of NTDS for super hybrid rice production had no significant impacts on seed yield and yield components of oilseed rape in rice–oilseed rape cropping system. Our study showed that CTTP could be replaced with NTDS to maintain yield and save labor for super hybrid rice production in rice–oilseed rape cropping system.     

Mineral nitrogen dynamics in irrigated rice–wheat system under different irrigation and establishment methods and residue levels in arid drylands of Central Asia

Increasing water shortage and low water productivity in the irrigated drylands of Central Asia are compelling farmers to develop and adopt resource conservation technologies. Nitrogen (N) is the key nutrient for crop production in rice–wheat cropping systems in this region. Nitrogen dynamics of dry seeded rice-(aerobic, anaerobic) planted in rotation with wheat (well drained, aerobic) can differ greatly from those of conventional rice cultivation. Soil mineral N dynamics in flood irrigated rice has extensively been studied and understood, however, the impact of establishment method and residue levels on this dynamics remains unknown. Experiments on resource conservation technologies were conducted between 2008 and 2009 to assess the impact of two establishment methods (beds and flats) in combination with three (R0, R50 and R100) residue levels and two irrigation modes (alternate wet and dry (AWD) irrigation (all zero till), and a continuously flooded conventional tillage (dry tillage)) with water seeded rice (WSR) on the mineral N dynamics under dry seeded rice (DSR)-surface seeded wheat systems. N balance from the top 80 cm soil layers indicated that 32–70% (122–236 kg ha⁻¹) mineral N was unaccounted (lost) during rice cropping. The amount of unaccounted mineral N was affected by the irrigation method. Residue retention increased (p < 0.001) the unaccounted mineral N content by 38%. With AWD irrigation, the N loss was not different among dry seeded rice in flat (DSRF), dry seeded rice in bed (DSRB), and conventional tillage WSR. Under different irrigation, establishment methods and residue levels, unaccounted mineral N was mainly affected by plant N uptake and soil mineral N content. Major amounts (43–58%) of unaccounted mineral N from DSR field occurred between seeding and panicle initiation (PI). During the entire rice and wheat growing seasons, NH₄N consistently remained at very high levels, while, NO₃N remained at very low levels in all treatments. In rice, the irrigation method affected NH₄N content. Effect of residue retention and establishment methods were not significant on NH₄N and NO₃N dynamics in both crops and years. Further evidence of the continuously fluctuating water filled pore spaces (WFPS) of 64% and the microbial aerobic activity of 93% at the top 10 cm soil surface during rice growing season indicates soil in the DSR treatments was under frequent aerobic–anaerobic transformation, a conditions very conducive for higher amounts of N loss. In DSR treatments, the losses appeared to be caused by a combination of denitrification, leaching and N immobilization. When intending to use a DSR management strategies need to be developed for appropriate N management, irrigation scheduling, and residue use to increase mineral N availability and uptake before this practices can be recommended.     

Impact of tillage and mulch management on economics,energy requirement and crop performance in maize–wheat rotation in rainfed subhumid inceptisols,India

Different tillage systems (conventional, minimum, raised bed and no tillage) and four mulch levels (control, polythene, straw and soil) were compared in maize (Zea mays) and wheat (Triticum aestivum) production for three years on an experimental field (sandy loam) located at Dry Land Research Sub Station, Dhiansar, Jammu. Each treatment was replicated four times in split plot design. The aim of the research was to determine the influence of tillage and mulch practices on economics, energy requirement, soil physical properties and performance of maize and wheat. Tillage methods significantly affected the soil physical properties as change in soil moisture contents and infiltration rate of soil was recorded. The soil moisture contents in minimum tillage (MT) were maximum (12.4%, 16.6%) in surface soil as compared to conventional tillage (CT) in maize and wheat crops, respectively. Comparing to the CT infiltration rate was (1.16times, 1.21times and 1.11times) higher in minimum tillage (MT), no tillage (NT) and raised bed (RB), respectively in kharif season. Similar results were also found in rabi season. The greatest maize yield of 1865 kg ha^?1 was achieved with CT system while not significantly lower yield was achieved with MT system (1837 kg ha^?1). However, wheat yield was recorded higher in MT as compare to the CT system. Comparing to the energy requirement of different operations, MT required 34.3% less, NT 31.1% less and RB 46.0% less than the CT system. MT system saved 2.5 times energy in tillage operation compared to the CT system. The economic analysis also revealed that the maximum benefits could be obtained from MT (EUR 202.4 ha^?1) followed by RB (EUR 164.2 ha^?1) and NT (EUR 158.3 ha^?1) and lowest in CT (EUR 149.5 ha^?1). Benefit-cost ratio was highest in MT (0.71) and lowest in CT (0.44). Results revealed that mulch significantly affected the soil physical properties and growth of maize. The maximum soil moisture content, infiltration rate and grain yield of maize and wheat recorded higher in mulching practices over no mulch treatment. Polythene mulch and straw mulch were almost equally valuable in maize and wheat sequence. Tillage (minimum) and mulch (polythene and straw) have pronounced effect on soil physical properties (improved infiltration rate and conserve soil water), energy requirement, economics and growth of maize and wheat.     

Breeding potential of Solanum tuberosum–S. commersonii pentaploid hybrids: fertility studies and tuber evaluation

Twenty-one (near) pentaploid hybrids between sexually incompatible Solanum commersonii [2x(1EBN)] and cultivated S. tuberosum [4x(4EBN)] were characterized for tuber traits and fertility. A number of genotypes resembled the S. tuberosum type in terms of stolon length and eye depth and produced tubers under long day conditions. Tuber yields were not as high as expected, probably due to lack of adaptation of the S. commersonii genome to the environmental conditions in southern Italy (on average 325 g·pt⁻¹ and 285 g·pt⁻¹ in 2003 and in 2004, respectively). Compared to 2004, in the summer of 2003, characterized by extremely high temperatures, hybrids gave a higher tuber yield than the S. tuberosum control, suggesting that in our environmental conditions the wild S. commersonii genome, rather than resulting in heterosis for tuber yield, provides better adaptation to harsh environments. Although aneuploidy has often been associated with reduced fertility, several hybrids were fertile in crosses with S. tuberosum when used as female parents. In particular, the average berry set and number of seeds per berry were 38.2% and 31.8%, respectively. Based on significant relationships between ploidy levels and all yield and fertility data measured, the presence of extra chromosome affected the parameters considered: tuber yield in 2003 and 2004, percentage of fruit set, number of seeds per berry and number of seeds per pollinated flower. Regression analysis also indicated that “Residuals” were significant for all parameters measured. Therefore, additional factors (e.g. the genetic makeup of hybrids) may be key to fertility and yield.     

Effects of a composite chitosan–gelatin edible coating on postharvest quality and storability of red bell peppers

For the first time, a composite chitosan–gelatin (CH–GL) coating was applied to peppers and its effects on fruit quality and storability were examined. Pure chitosan (CH) and gelatin (GL) coatings were studied for comparison. The CH coating inhibited microbial spoilage and prolonged the possible storage period. The GL coating contributed to fruit firmness, but did not allow for prolonged storage. The composite CH–GL coating was associated with a two-fold decrease in microbial decay, significantly (p ≤ 0.05) enhanced fruit texture and prolonged the possible period of cold storage up to 21 days and fruit shelf-life up to 14 days, without affecting the respiration or nutritional content of the fruit.     

Long-term studies on Noctiluca scintillans in the German Bight population dynamics and red tide phenomena 1968–1988

The seasonal development of Noctiluca scintillans has been studied by continuous monitoring at Helgoland-Roads over a period of 20 years. These long-term studies have revealed a temporal distribution pattern of seasonal periodicity with maximal abundances in June/July, and with a low but pronounced peak in December/January. Additionally, over a 21-year term a periodicity of high abundances in three years intervals is observed. In Helgoland waters the mean near surface abundances are higher than the near sea bed values. Apart from physico-chemical influences, buoyancy in Noctiluca is also controlled by its nutritional status.Since 1981, investigations have been extended to the German Bight. Potential centres of Noctiluca growth are found within certain areas near the east-frisian Wadden Sea, persisting from April/May until late July when the centres of high cell concentrations are separated from the coastline. Simultaneously, there is a strong tendency for vertical separation, generating the well-known red-tide phenomena with large mass aggregations at the sea surface, often misleadingly called Noctiluca-blooms, although the cell masses are irreversibly damaged and die off very rapidly.The spatial distribution of Noctiluca as determined every year in July, serves as a realistic base for biomass calculations. From 1981 to 1988 the total per season produced biomass (ashfree dry-weight) of Noctiluca ranges between 30000 (1981) and 69000 tons (1982).     

Great Recession and club convergence in Europe: A cross-country,cross-region panel analysis (2000–2015)

The paper aims at investigating the impact of the Great Recession on per capita GDP convergence process across European regions and countries. Using the time-varying factor model developed by Phillips and Sul for the period 2000–2015 and two different merging procedures to identify clubs, we provide evidence of the diverging impact of the Great Recession “between” the higher and the lower convergence clubs at both regional and country levels as well as of the strengthening of the convergence process “within” most clubs. In addition, we add further evidence to the common belief of a “multi-speed” Europe by contrasting Eastern European countries' and regions' behavior vis-à-vis original European members' one, and by identifying the factors that affect club membership and resilience to the recent economic downturn. We find that the membership in the higher clubs and resilience to the Great Recession are positively affected by the presence of several local-specific factors and macroeconomic characteristics.     

Genetic diversity of wheat–rye 1BL.1RS translocation lines derived from different wheat and rye sources

Many studies have been conducted to determine the relative effects of the 1BL.1RS translocation on various traits in wheat. The effects of different wheat (Triticum aestivum L.) genetic backgrounds and rye (Secale cereale L.) sources have been addressed as major factors for inconsistent agronomic performance and end-use-quality traits of 1BL.1RS translocation wheats. However, all these studies were accomplished by using 1BL.1RS translocations with impure wheat genetic bases and narrow rye origins. The objective of this study was to test the genetic effects of centric fusion translocations by using primary 1BL.1RS lines derived from various pure wheat lines and rye sources. Twenty-one primary 1BL.1RS translocation lines were created from crosses between two pure wheat lines and three Chinese local rye varieties. These translocation lines and their wheat parents were then evaluated in southwestern China. The results provide direct evidence of the diverse effects of the different wheat parents and rye sources, taking part in 1BL.1RS translocations, on resistance to diseases, agronomic performance, and end-use quality traits. The highest amount of genetic diversity was observed in 1BL.1RS translocations derived from the same wheat lines and diverse rye varieties. The results suggest that the genetic diversity of 1BL.1RS translocation lines may originate from the different wheat genetic backgrounds, from different rye sources, from their interaction, and from the translocation itself. Creation of diverse 1BL.1RS translocations offers ample possibilities to introduce more variation into wheat for improved performance.     

Approaches and Applications of Chemomics and Chemoinformatics

Some novel concepts of chemomics/molomics are proposed including hydrocarbomics, alcophenomics, carboxomics, pepitomics, metabonomics, etc. like genomics, protomics and glycomics in bioomics. Some examples are given to demonstrate the chemomics and/or molomics methodology and technology based chemoinformatics and bioinformatics and their wide applications in Chemistry and Biology.     

The winter distribution of nutrients in the Southern Bight of the North Sea (1961–1978) and in the estuaries of the scheldt and the rhine/meuse

In many years the winter distribution of nutrients in the eastern part of the Southern Bight is influenced by phytoplankton growth, always in February, sometimes in January but not in January 1961 and 1978, months with a relatively low insolation and high wind strength. The Scheldt river has higher nutrient concentrations than the rivers Rhine and Seine. The waters of the Scheldt river plume are distinguished from those of the Seine and the Rhine/Meuse with dissolved silica as a tracer. The extension of the Scheldt river plume is related to wind direction.The increase of inorganic nutrients from January 1961 to January 1978 in the northern part of the Southern Bight is related to the increase in the river Rhine. The increase in the Strait of Dover is related to discharges from the river Seine and the English coast. Only data outside the Scheldt river plume were selected for the comparison. An increase of nutrient concentrations is measurable over the entire salinity range and is largest for phosphate (up to 3 times at low salinities), less for nitrate (about 1.5 times for all salinities) and hardly noticeable for silicic acid. Nitrate extrapolation to low salinity agrees with upstream river values, but phosphate extrapolation gives higher concentrations, probably due to discharges of phosphogypsum in estuaries.     

Identifying QTL–allele system of seed protein content in Chinese soybean landraces for population differentiation studies and optimal cross predictions

Soybean originated in ancient China has been quickly extended globally as a major protein and oil crop. The QTL–allele constitution of seed protein content (SPC) in the Chinese soybean landrace population (CSLRP) was studied using a representative sample composed of 365 accessions tested under multiple environments and analysed under the novel restricted two-stage multi-locus genome-wide association study (RTM-GWAS) procedure based on 29,121 SNPLDB (single nucleotide polymorphism linkage disequilibrium blocks) markers. The SPC varied from 37.51 to 50.46% among accessions, for which 89 QTLs, each with 2–9 alleles in a total of 255 alleles were identified, accounting for 83.16% of the phenotypic variation covering most of the genetic variation (h²?=?84.31%). The QTL–alleles of the 365 landraces were organized into a 255?×?365 QTL–allele matrix as the compact form of SPC genetic constitution in CSLRP. Of the 89 QTLs, 53 showed significantly differentiated allele frequency distribution patterns among geographic eco-regions (sub-populations). There were 32.09% alleles not common among sub-populations but found only in some sub-populations; new allele(s) emerged on some loci in some respective sub-populations, with Eco-region III showing less but Eco-region VI more emergence. The QTL–allele matrix was also used for prediction of optimal crosses for breeding purpose to reach a 99th percentile potential of up to 54.81%, more than the highest accession (50.46%). From the 89 QTLs, 59 SPC candidate genes involving biological processes, cellular components and molecular functions were annotated. Among them, Glyma18g13574 and Glyma20g21370 were inferred as two of the major SPC genes in the whole genome.     

Energy Conservation and Energy Using and Recycling Energy

With science and technology developing, the need of energy increases in our lives and industries. Normal energy is lacking in our country, and the average is half of the average of the world. The conflicting between supplying and needing is apparent. So it seems that the energy may be gone. It is necessary that development of recycling energy is considered. The new energy and recycling energy will be the main energy in the future.