The inheritance and chromosomal location of morphological traits in wild wheat, Triticum turgidum L. ssp. dicoccoides

The homoeologous groups of chromosomes carrying the genes for some morphological traits in wild wheat Triticum turgidum L. ssp. dicoccoides (T. dicoccoides) were determined, but not the actual chromosomes carrying them. The objectives of this study were to investigate the modes of inheritance, and determine the chromosomes carrying some morphological traits in wild emmer (2n = 28; AABB), the progenitor of most cultivated wheats. To investigate the inheritance of morphological traits, crosses were made between T. turgidum L. ssp. durum (T. durum cultivar Chartokhmi (IR10) and T. dicoccoides accessions TA1150 and TA1131. F₂ seeds from each cross were grown in the field and six qualitative characters were investigated. Purple coleoptile, purple auricle, purple culm, hairy auricle, hairy rachilla, and fragility of spike were controlled by single dominant genes. To determine the chromosomal locations, accession TA1131 was crossed with the complete set of LDN D-genome disomic substitution lines. Assessments of F₂ populations showed that chromosomes 7A, 6A, 7B, 5B, 5A and 3B carried genes for purple coleoptile, purple auricle, purple culm, hairy auricle, hairy rachilla and brittle rachis, respectively.     

Comparative Effects of Organic and Inorganic Fertilizers on Soil Organic Carbon and Wheat Productivity under Arid Region

ABSTRACT

Organic amendments in the soil perform better than synthetic fertilizers in regards to soil fertility and sustainable crop productivity. Experiments were conducted to compare the effects of organic and synthetic fertilizers on soil fertility and wheat (Triticum aestivum L.) productivity. Soil fertility and protein contents of wheat grains (13.2% and 13.3% during 2005–06 and 2006–07, respectively) were improved by organic amendments. However, synthetic fertilizer (at the rate of 150, 100, and 60 kg ha^?1 N, P₂O₅, and K₂O, respectively) applications resulted in the maximum grain yield (4.05 and 4.46 t ha^?1 during 2005–06 and 2006–07, respectively). The observed and simulated soil organic carbon (SOC) reasonably agreed during RothC model validation (R ² = 0.99). Economic analysis showed the maximum net profit and relative increase in income ($729 US ha^?1 and 309%, respectively) from inorganic treatment. Application of synthetic fertilizers increased grain yield and farm profit while organic manure enhanced grain quality. The RothC model had potential for determining the SOC in organic farming under arid environment.     

Supernova remnant OH masers: signposts of cosmic collision

A supernova explosion, the final death throe of a massive star, creates an expanding bubble of hot gas that overruns up the surrounding medium. When a supernova remnant encounters a dense interstellar cloud, the compression may trigger gravitational collapse and the formation of a new generation of stars. This event can be detected through intense stimulated emission in the 1720-megahertz transition of the hydroxyl radical, OH, which yields unique insights into the physical processes and conditions occurring during the interaction.     

Regulation of blood and lymphatic vascular separation by signaling proteins SLP-76 and Syk

Lymphatic vessels develop from specialized endothelial cells in preexisting blood vessels, but the molecular signals that regulate this separation are unknown. Here we identify a failure to separate emerging lymphatic vessels from blood vessels in mice lacking the hematopoietic signaling protein SLP-76 or Syk. Blood-lymphatic connections lead to embryonic hemorrhage and arteriovenous shunting. Expression of slp-76 could not be detected in endothelial cells, and blood-filled lymphatics also arose in wild-type mice reconstituted with SLP-76-deficient bone marrow. These studies reveal a hematopoietic signaling pathway required for separation of the two major vascular networks in mammals.     

A four-base paired genetic helix with expanded size

We describe a new molecular class of genetic-pairing system that has a native DNA backbone but has all four base pairs replaced by new, larger pairs. The base pairs include size-expanded analogs of thymine and of adenine, both extended by the width of a benzene ring (2.4 A). The expanded-diameter double helices are more thermodynamically stable than the Watson-Crick helix, likely because of enhanced base stacking. Structural data confirm a right-handed, double-stranded, and base-paired helical form. Because of the larger base size, all the pairs of this helical system are fluorescent, which suggests practical applications in detection of natural DNA and RNA. Our findings establish that there is no apparent structural or thermodynamic prohibition against genetic systems having sizes different from the natural one.     

Effect of Foliar Applications of Humic Acid on Growth,Visual Quality,Nutrients Content and Root Parameters of Perennial Ryegrass (Lolium Perenne L.)

In recent years, applying humic acid (HA) has been common in turfgrass management. A series of experiments were conducted to evaluate the effect of HA on qualitative and quantitative characteristics of “Speedygreen” perennial ryegrass (Lolium perenne L.). Different concentrations of HA (0, 100, 400, and 1000 mg L^?1) were applied monthly as foliar application. Results showed that leaf phosphorus (P), potassium (K), and zinc (Zn) content, fresh and dry weight, chlorophyll content, and root fresh weights were not affected by HA. Meanwhile, HA improved the root and shoot development, except for root fresh weight. While just 100 mg L^?1 improved height, visual quality, nitrogen (N) content, roots length, and surface of roots, all of HA concentrations were effective on iron content. These results suggest that HA foliar application might be of benefit to enhance some nutrients uptake and root development of ryegrass possibly leading to improved drought resistance.     

Salinity threshold value of Quinoa (Chenopodium Quinoa ‎Willd.) at ‎various growth stages and the appropriate ‎irrigation method by saline ‎water

Salinity is one of the major agricultural problems in arid and ?semi-arid regions. Considering the variation of plant’s ?sensitivity to salinity during growth, a greenhouse study with completely randomized design? was conducted to determine the relative salinity tolerance of Quinoa (Chenopodium quinoa Willd.) at different growth stages from seedling establishment to maturity (establishment, flowering and seed filling) by evaluating the Salinity Threshold Value (STV). Eight levels of EC_i (i.e., Non-saline, 2, 4, 8, 12, 15, 20, 25 dSm^?1) with four replications and five levels (i.e., Non-saline, 10, 15, 20, 25 dSm^?1) with three triplications were applied at first and two last growth stages, respectively. A ?comparison was performed on some growth and yield parameters of plants irrigated by considering STV (T) and ?plants irrigated permanently by mentioned salinity levels regardless of STV (P) to choose ?which method (P or T) is better at each salinity level. The STV was ?evaluated 8, 20 and 15 dSm^?1 at each growth stage, respectively. Seedling of Quinoa was more sensitive to salinity than the mature plant. Therefore, after establishment Quinoa has the ?feasibility of irrigation by high-saline waters. The (P) ?method was suitable only if the freshwater was available during all growth period of the plant; otherwise at higher salinities irrigation should be performed by considering STV (T method) to minimize the intensity of growth and yield reduction and to prevent yield loss at very high salinities. To achieve this, if high-saline water is available it’s possible to ?use plant propagation techniques or cultivating Quinoa simultaneously with seasonal rainfall.?     

Population connectivity: recent advances and new perspectives

Landscape Ecology - Connectivity is a vital component of metapopulation and landscape ecology, influencing fundamental processes such as population dynamics, evolution, and community responses to...     

Rose flower production as related to plant architecture and carbohydrate content: Effect of harvesting method and plant type

Summary

The dependence between flowering cycles and woody stem parts of a rose crop was studied, with respect to plant architecture and carbohydrate content. Two harvesting methods (“control” versus “flush”) and two plant types (“control” versus “one stemmed”) were compared. Crop growth and partitioning of dry matter were studied as influenced by crop management during 18 months of culture. For a full-productive year, flush harvesting generally promoted bud break as compared with continuous harvesting but at the same time, also due to lower light interception, blind-shoot formation was enhanced and the individual flower weight reduced. Numbers of basal shoots were hardly related to flower production over a full cropping year. Flower production was much more sensitive to the number and diameter of branches at the height of cutting the flowers. The treatments did not affect carbohydrate allocation in the plant. Total carbohydrate storage was much too low to argue a clear role for the possible use of movement of carbohydrate reserves towards new growth. Maximum starch concentration was found at the beginning of summer and gradually dropped to a minimum in December and then increased again to a spring maximum. A cold treatment did increase the total non-structural carbohydrate (TNC) concentration but no positive influence on new basal-shoot formation was observed. No starch gradient was found in basal stem parts.     

Oxygen exchange with water alters the oxygen isotopic signature of nitrate in soil ecosystems

Combined oxygen (O) and nitrogen (N) stable isotope analyses are commonly used in the source determination of nitrate . The source and fate of are studied based on distinct O and N isotopic signatures (δ¹⁸O and δ¹⁵N) of various sources and isotopic effects during transformation processes, which differ between sources like fertilizer, atmospheric deposition, and microbial production (nitrification). Isotopic fractionation during production and consumption of further affects the δ¹⁸O and δ¹⁵N signal. Regarding the δ¹⁸O in particular, biochemical O exchange between O from and H₂O is implicitly assumed not to affect the δ¹⁸O signature of . This study aimed to test this assumption in soil-based systems. In a short (24 h) incubation experiment, soils were treated with artificially ¹⁸O and ¹⁵N enriched . Production of from nitrification during the incubation would affect both the ¹⁸O and the ¹⁵N enrichment. Oxygen exchange could therefore be studied by examining the change in ¹⁸O relative to the ¹⁵N. In two out of the three soils, we found that the imposed ¹⁸O enrichment of the declined relatively more than the imposed enrichment. This implies that O exchange indeed affected the O isotopic signature of , which has important implications for source determination studies. We suggest that O exchange between and H₂O should be taken into consideration when interpreting the O isotopic signature to study the origin and fate of in ecosystems.