Miracle-dz/UniFAR-FTUs huggingface dataset:
Chromosomal polymorphism in Serrasalmus spilopleura Kner, 1858 (Characidae, Serrasalminae) from Central Amazon Basin

Abstract Cytogenetic studies were performed in Serrasalmus spilopleura, a piranha species, from three sampling sites in the Central Amazon basin: 1. Catalão; 2. Manacapuru, 3. Itacoatiara. All specimens displayed 2n = 60 chromosomes and no sexual chromosomal heteromorphism was found. However, by considering the karyotypic formula, three cytotypes were identifyed: cytotype A consisted of 24M+20SM+4ST+12A, and was the most common being found in all three sampling sites; cytotype C consisted of 23M+21SM+4ST+12A, was found only in Catalão and differ from cytotype A by the presence of a heteroziguous inversion in the first chromosome pair and a distal heterocromatinization in the long arm of this same pair, probably caused by the rearrangement or due to a chromosomal adjustment; cytotype D consisted of 24M+20SM+4ST+12A, was found only in Manacapuru and differ from cytoytpe A by a heteroziguous size polymorphism on the second chromosome pair, probably due to a translocation. C-banding revealed the same constitutive heterochromatin pattern for the three cytotypes except for the chromosome pair that underwent pericentric inversion (cytotype C) which possessed different heterochromatic blocks. Analysis in the number of active nucleolar organizing regions (NORs) revealed no differentiationamong cytotypes and NOR-bearing chromosomes varied from 10–12 acrocentric chromosomes.
The distribution, density and biomass density of lizards in a semi–arid environment of northern Kenya*

Summary An attempt was made to determine the species composition, density and biomass density of lizards in some of the principal land units in South Turkana. Thirteen species were recorded. Density estimates were determined from quadrat sampling in representative habitats. Because the number of lizards active was found to vary with time of day and temperature, minimum density estimates were obtained by confining counts to peak activity periods. Biomass density was calculated from the product of species density and the mean population weight measured from shot specimens. The biomass density estimate of the lizard fauna was found to be about 4–5% of the large mammal fauna, and appreciably more in the more arid land units. The species composition of South Turkana lizards show affinities to the Somali fauna, though not to the extent of the East Rudolf fauna, suggesting a more recent penetration of arid–adapted species.
Types and components of resistance to Fusarium head blight of wheat

Resistance of wheat to Fusarium head blight caused by Fusarium graminearum and F. culmorum was identified in natural epidemics in 1985 and 1987 as well after artificial inoculations (1983–1988 and 1984–1987). Out of 25 genotypes tested, five were identified with no significant difference in head blight scores, but differing significantly in yield after artificial inoculation, i.e. tolerance differences were detected at different resistance levels. Some genotypes that were similar in yield or head blight scores differed in seed infection severity. Genotypes with awns were more susceptible to head blight when tested under natural epidemic condition in the field; but this trait did not influence head blight severity in artificial inoculations. Dwarf genotypes were more severely infected by head blight than tall genotypes under natural conditions, but genotypes of different plant height classes were similarly susceptible after artificial inoculations. In the early generations of a breeding programme resistance measured by visual evaluation of artificial inoculation is the most important way to screen. If selection of dwarf and awned genotypes cannot be avoided, the higher susceptibility caused by awns and dwarfness under natural epidemic conditions can be decreased by a higher level of physiological resistance, as variability in physiological resistance is available. In later generations, traits like percentage of seed infection or tolerance can be identified by additionally measuring yield reduction. Stability of disease reaction appears to be connected with resistance level, the most resistant genotypes are the most stable, and the most susceptible ones tend to have more unstable reactions in different epidemic conditions.
Exploring patterns and mechanisms of interspecific and intraspecific variation in body elemental composition of desert consumers

Key processes such as trophic interactions and nutrient cycling are often influenced by the element content of organisms. Previous analyses have led to some preliminary understanding of the relative importance of evolutionary and ecological factors determining animal stoichiometry. However, to date, the patterns and underlying mechanisms of consumer stoichiometry at interspecific and intraspecific levels within natural ecosystems remain poorly investigated. Here, we examine the association between phylogeny, trophic level, body size, and ontogeny and the elemental composition of 22 arthropod as well as two lizard species from the coastal zone of the Atacama Desert in Chile. We found that, in general, whole-body P content was more variable than body N content both among and within species. Body P content showed a significant phylogenetic signal; however, phylogeny explained only 4% of the variation in body P content across arthropod species. We also found a significant association between trophic level and the element content of arthropods, with carnivores having 15% greater N and 70% greater P contents than herbivores. Elemental scaling relationships across species were only significant for body P content, and even the P content scaling relationship was not significant after controlling for phylogeny. P content did decrease significantly with body size within most arthropod species, which may reflect the size dependence of RNA content in invertebrates. In contrast, larger lizards had higher P contents and lower N:P ratios than smaller lizards, which may be explained by size-associated differences in bone and scale investments. Our results suggests that structural differences in material allocation, trophic level and phylogeny can all contribute to variation in the stoichiometry of desert consumers, and they indicate that the elemental composition of animals can be useful information for identifying broad-scale linkages between nutrient cycling and trophic interactions in terrestrial food webs.
Aspects of nitrogen metabolism in coffee plants

Coffee plants are highly N-demanding plants. Despite the importance of N nutrition for the development, acclimation and yield of coffee plants, there are few reports concerning N metabolism in this species. In this review, our intention is to summarize the information available in the literature and to point out the influence of environmental conditions on N assimilation, as well as com-ment and discuss some apparently contradictory results and raise and enlighten queries about N assimilation in coffee plants.Key words: Coffea, irradiance level, nitrate reductase, nitrogen fertilization, oxidative stress, photoinhbition, photoprotection, photosynthesis.Aspectos do metabolismo de nitrogenio em plantas de cafe: Plantas de cafedemandam grandes quantidades de N. Apesar da importância da nutricao nitrogenada para o desenvolvimento, aclimatacao e produtividade de plantas de cafe, sao poucos os trabalhos sobre o metabolismo de N nesta especie. A intensao desta revisao e sumarizar a informacao disponivel na literatura e discutir a influencia das condicoes ambientais na assimilacao de N, assim como comentar e discutir alguns resultados aparen-temente contraditorios e levantar e destacar perguntas sobre a assimilacao de N em plantas de cafe.Palavras-chave: Coffea, estresse oxidativo, fertilizacao nitrogenada, fotoinibicao, fotoprotecao, fotossintese, nivel de irradiância, redutase do nitrato.
Grazing winter wheat. I: Response of semidwarf cultivars to grain and grazed production systems

Most wheat (L.) research in west Texas is conducted in ungrazed wheat that is managed solely for grain production (grain system). In contrast, most commercial wheat is planted early and grazed by cattle () prior to management for grain production (grazed system). The objective of this research was to understand cultivar × production system interactions. Four semidwarf cultivars, TAM 105, Newton, Vona, and TAM 108, were grown in irrigated grain and grazed production systems for 3 yr. Grazed wheat headed 2.3 d later, had 57 and 62% as much above-ground biomass and leaf area at heading, was 80% as tall, and yielded 80% as much as wheat grown in the grain system. There was a significant cultivar × system interaction for grain yield 2 yr (= 0.088 in 1982, = 0.001 in 1984) caused by differential cultivar response to yield constraints such as lodging, winterkilling, and shattering. In the 3-yr combined analysis there was no cultivar × system interaction; however, the cultivar × system × year interaction for grain yield was significant (= 0.003) because yield constraints within systems were not consistent across years. In 1984, extra fertilizer and insecticide reduced grain yield of TAM 108 by 18% (= 0.001) in the grain system due to increased lodging while having no measurable effect on grain yield in the grazed system. If production systems frequently differ in type or degree of yield constraints, then breeders and agronomist must be concerned with cultivar × system interactions.
The influence of nitrogen supply on the ability of wheat and potato to suppress Stellaria media growth and reproduction

This paper tests the hypothesis that increased soil nitrogen supply reduces the growth of late-emerging weeds in wheat and potato by enhancing canopy leaf area development and thereby reducing the availability of light for weed growth. Two series of experiments were conducted: one in spring wheat (1997, 1999) with sown Stellaria media and one in potato (1998, 1999) with naturally emerged weeds, including S. media. For each crop, two cultivars were grown at three levels of nitrogen supply. In wheat, as in a monoculture of S. media, total dry weight and seed number of the weed increased with soil nitrogen supply, whereas in potato the opposite was found. Increased soil nitrogen supply increased the nitrogen uptake of S. media in wheat, despite the reduced light availability, indicating that S. media in wheat was limited by nitrogen. In potato, on the other hand, growth of S. media was limited by light availability, which decreased with increased soil nitrogen supply. We conclude that the differences in response of S. media in wheat and potato to additional nitrogen supply are attributable to the dual influence of soil nitrogen supply on light and nitrogen availability, which are mediated by the crops.
Belowground drought response of European beech: fine root biomass and carbon partitioning in 14 mature stands across a precipitation gradient

How tree root systems will respond to increased drought stress, as predicted for parts of Central Europe, is not well understood. According to the optimal partitioning theory, plants should enhance root growth relative to aboveground growth in order to reduce water limitations. We tested this prediction in a transect study with 14 mature forest stands of European beech (Fagus sylvatica L.) by analysing the response of the fine root system to a large decrease in annual precipitation (970–520 mm yr−1). In 3 years with contrasting precipitation regimes, we investigated leaf area and leaf biomass, fine root biomass and necromass (organic layer and mineral soil to 40 cm) and fine root productivity (ingrowth core approach), and analysed the dependence on precipitation, temperature, soil nutrient availability and stand structure. In contrast to the optimal partitioning theory, fine root biomass decreased by about a third from stands with >950 mm yr−1 to those with <550 mm yr−1, while leaf biomass remained constant, resulting in a significant decrease, and not an increase, in the fine root/leaf biomass ratio towards drier sites. Average fine root diameter decreased towards the drier stands, thereby partly compensating for the loss in root biomass and surface area. Both δ13C‐signature of fine root mass and the ingrowth core data indicated a higher fine root turnover in the drier stands. Principal components analyses (PCA) and regression analyses revealed a positive influence of precipitation on the profile total of fine root biomass in the 14 stands and a negative one of temperature and plant‐available soil phosphorus. We hypothesize that summer droughts lead to increased fine root mortality, thereby reducing root biomass, but they also stimulate compensatory fine root production in the drier stands. We conclude that the optimal partitioning theory fails to explain the observed decrease in the fine root/leaf biomass ratio, but is supported by the data if carbon allocation to roots is considered, which would account for enhanced root turnover in drier environments.
Correlation between xylem ureide levels and nodulation in field-grown Phaseolus vulgaris

The relationships between the relative abundance of ureide-N in xylem sap and nodulation characteristics of navy beans (Phaseolus vulgaris) were examined in a sandy field site that enabled good nodule recovery. Three management treatments of N fertiliser, inoculation and no inoculation were used in the irrigated trial. Five cultivars were sown, and they were sampled 48 and 83 days later. Plant roots were scored visually for nodule size, colour, abundance and mass. Xylem sap was extracted from shoots under mild vacuum and assayed for ureide, nitrate and amino-N contents. Main treatment effects on nodulation were detected in the first but not the second sampling. Cultivar differences were found in the second sampling only. The relative abundance of ureide-N in xylem sap, measured as 100 x 4 x ureides/(4 x ureides + nitrate + amino-N), was low (<20%) in the first sampling, with no differences between cultivars. Fertiliser N depressed the ureide levels. At the second sampling, relative ureide-N ranged from 30 to 40% but there were no differences between management treatments or cultivars. Correlations between relative ureide-N and nodulation characteristics (abundance, size, colour, mass) were significant for each sampling (48 days, r = 0.29-0.33; 83 days, r = 0.72-0.76). The results indicate that it is possible to use a ureide assay as an alternative to nodule scoring where nodule recovery is impracticable in field studies of P. vulgaris.
Influence of Carvacrol on the Growth Performance, Hematological, Non-Specific Immune and Serum Biochemistry Parameters in Rainbow Trout (Oncorhynchus mykiss)

The present study investigated the effects of phytoadditive carvacrol on growth performance, feed utilization, hematological, non-specific immune and serum biochemical parameters in rainbow trout (Oncorhynchus mykiss). In trial, 240 rainbow trout which had average weight of 10.79 ± 0.57 was used. Fish were divided into four groups before being fed for 60 days with 0, 1 (C1), 3 (C3) or 5 (C5) g/kg of carvacrol. There were no particular differences in the growth performance, feed utilization, whole body composition, hematological parameters between the experimental group and the control group. However, as compared to control group, a significant increase of serum lysozyme activity was seen in groups receiving feed containing C3 and C5 groups after 30 days. The myeloperoxidase activity in groups (C1 and C3) was significantly higher on the 30th day of sampling. Myeloperoxidase activity of C5 treated group was significantly higher on the 60th day in comparison with the control group. Serum glucose levels significantly decreased on 60th day for C1, C3 and C5 treated groups. The serum total protein, globulin and triglyceride levels of C3 treated groups was significantly higher on the 60th day in comparison with the control and other carvacrol treated groups. The level of serum cholesterol in C5 treated groups was significantly lower on the 30th day in comparison with the control and other carvacrol treated groups. The results of the present study indicated that dietary supplementation of 3 g/kg of carvacrol in commercial diets could improve some non-specific and biochemical status in rainbow trout.
Quantum Yields for CO2 Uptake in C3 and C4 Plants: Dependence on Temperature, CO2, and O2 Concentration

The quantum yields of C3 and C4 plants from a number of genera and families as well as from ecologically diverse habitats were measured in normal air of 21% O2 and in 2% O2. At 30 C, the quantum yields of C3 plants averaged 0.0524 ± 0.0014 mol CO2/absorbed einstein and 0.0733 ± 0.0008 mol CO2/absorbed einstein under 21 and 2% O2. At 30 C, the quantum yields of C4 plants averaged 0.0534 ± 0.0009 mol CO2/absorbed einstein and 0.0538 ± 0.0011 mol CO2/absorbed einstein under 21 and 2% O2. At 21% O2, the quantum yield of a C3 plant is shown to be strongly dependent on both the intercellular CO2 concentration and leaf temperature. The quantum yield of a C4 plant, which is independent of the intercellular CO2 concentration, is shown to be independent of leaf temperature over the ranges measured. The changes in the quantum yields of C3 plants are due to changes in the O2 inhibition. The evolutionary significance of the CO2 dependence of the quantum yield in C3 plants and the ecological significance of the temperature effects on the quantum yields of C3 and C4 plants are discussed.
New Data on the Late Cretaceous Cardabiodontid Lamniform Shark Based on an Associated Specimen from Kansas

We describe a specimen of an Upper Cretaceous shark, Cardabiodon sp. (Lamniformes: Cardabiodontidae), from Kansas. This specimen, that consists of a set of teeth, pieces of calcified cartilage, and placoid scales, represents the first associated cardabiodontid material from North America. The combination of direct observation and radiographic examination reveals that the specimen contains at least 78 teeth, including presumed functional and replacement teeth. The teeth vary in size and morphology, suggesting that the dentition of the shark showed heterodonty. The tooth set includes teeth referable to ‘upper intermediate teeth’ in which their presence is characteristic of the order Lamniformes. This shark individual is estimated to have measured at least 2.5 m and as much as 3.8 m in total length. The morphology of placoid scales indicates that Cardabiodon was capable of fast swimming and was likely able to actively pursue lively prey.
Enzymatic hydrolysis of palm oil mill effluent solid using mixed cellulases from locally isolated fungi

In order to optimize the enzymatic hydrolysis of POME solid, the effects of substrate pretreatment using varying concentrations of sodium hydroxide and sulfuric acid, crude enzyme from both strains in different ratio and pH reaction were studied. The best experimental conditions found to degrade POME solids were 12 h incubation time, 0.5% (v/v) sulfuric acid pretreatment, crude enzymes mixture from Aspergillus niger EB5 and Trichoderma sp. EB6 (1.75 mL Asp+0.25 mL Tri with the total cellulase activity equal to 14.76 IU) and incubation pH at 5.0. Under these conditions, the reducing sugar concentration reached 23 g L-1 with the hydrolysis yield and productivity at 32% and 1.90 g L-1 h-1, respectively. The bioconversion of POME solid to reducing sugar by the mixture of crude enzyme from the strains was relatively higher by almost 2 folds as compared to commercial cellulase. The results suggested that the crude cellulases mixture from locally isolated fungi has potential for hydrolyzing the abundant agriculture residues from the palm oil industry.
Effect of Organic Wastes and Method of Composting on Compost Maturity, Nutrient Composition of Compost and Yields of Two Vegetable Crops

ABSTRACT Two field experiments were carried out to evaluate the effect of composts prepared from different organic waste materials on two vegetable crops. Poultry litter with each of the following organic wastes, maize residues, leaf litter, urban waste, weed biomass and soybean residue, were composted using three methods of composting–Passively Aerated Composting Technique in a pile (PACT-1), Passively Aerated Composting Technique in a plastic pot (PACT-2) and Windrow (Wdr). Tomato (Lycosipercum esculentum Mill.) and amaranthus (Amaranthus cruentus) were planted as test crops. The C:N ratio and nutrient concentrations varied with type of organic waste materials. The leaf litter and weed biomass contained high C:N ratio (38 and 45, respectively) and therefore produced composts that matured a few weeks later than those from organic wastes with C:N ratio falling within the optimum range of 25-35. The C:N ratio of the organic wastes were highly reduced at the end of composting. Irrespective of method used for composting, N in the soybean-based compost increased by 37-71% over the concentrations in the other composts. Phosphorus in the leaf litter- and soybean-based composts increased by 13.6-34.9% over the level in the urban and weed-based composts. However, K levels in the maize- and weed-bio-mass based composts increased by 7-37% over other composts. Soybean- and leaf litter-based composts in general were greater in both secondary and micronutrient elements than other composts. The results from field evaluation indicated that the effectiveness of the composts on amaranthus productivity can be rated in the ascending order of soybean, leaf litter, weed, maize and urban waste composts. For tomato, the composts from maize and soybean residues were more effective than other composts. Mostly, the effectiveness of the composts on the productivity of the vegetable crops varied according to methods of composting and followed in the ascending order of Wdr, PACT-1 and PACT-2.
Genetic diversity of Japanese chestnut cultivars assessed by SSR markers

The history of chestnut utilization in Japan is very long. Many cultivars have been preserved without being sufficiently organized and studied with respect to genetic variation. We developed 12 new SSR (simple sequence repeat) markers from Japanese chestnut (Castanea crenata) by using SSR-enriched genomic libraries. All 12 primer pairs selected for SSR analysis successfully amplified fragments in 6 Castanea species. The genetic diversity and relationships among 216 chestnut accessions were assessed by SSR markers, including 142 Japanese chestnuts, 38 Chinese chestnuts (C. mollissima), 2 European chestnuts (C. sativa), 9 American chestnuts (C. dentata), and 23 Japanese–Chinese hybrids. Among the 216 accessions, we identified 21 synonym groups (including 1 bud sport group), and 189 different genotypes. The mean values of observed heterozygosity (HO) and the expected heterozygosity (HE) in the Japanese chestnuts were 0.65 and 0.65, respectively. A phenogram of the 189 genotypes revealed 3 major groups, corresponding to Japanese, Chinese and American chestnuts. Japanese–Chinese hybrid cultivars were mainly included in the Chinese chestnut group. In the present study, genetic backgrounds could be identified for native and cultivated Japanese chestnuts and Japanese–Chinese hybrid cultivars, and many synonyms showing identical SSR genotypes were found. Genetic and geographical relationships of unique characteristics such as “Shidareguri” (weeping) and “Togenashi” (spineless) were also discussed. These results will improve the efficiency of cultivar identification and of chestnut breeding programs.