Analysis of genetic variability and agronomic performance of Indian lettuce (Lactuca indica L.)

Genetic Resources and Crop Evolution - Lactuca indica L. is an undomesticated medicinal crop in the Asteraceae family. The study was carried out to identify elite genotypes for lettuce cultivation...     

Selenium Concentration in Spring Wheat and Leaching Water as Influenced by Application Times of Selenium and Nitrogen

ABSTRACT

Selenium (Se) deficiency in Scandinavian soils is a common problem, and crops generally contain inadequate amounts to meet human need. This study shows a relationship of the Se concentration in spring wheat (Triticum aestivum L., c.v. ‘Helena’) and leaching water with timing of nitrogen (N) [as ammonium nitrate (NH₄NO₃)] and Se [as sodium selenate (Na₂SeO₄)] application. Ammonium-nitrate was applied by two methods (i) whole amount at sowing and (ii) in split application as 75% at sowing and 25% at stem elongation. Selenate was applied at cereal growth stages after sowing, e.g., tillering, stem elongation, head emergence, and milking. Split N application in comparison to one N application increased the grain protein content from 12.1 to 13.7 mg g^{? 1}, and grain Se was increased from 0.8 to 1.1 mg kg^{? 1} when Se was applied at stem elongation and from 0.6 to 0.9 mg kg^{? 1} when applied at heading. The highest Se concentration in plant was achieved with the split N application and Se application at stem elongation or heading. Selenium leaching losses increased with increasing selenium concentration in the wheat grains. No differences in Se leaching losses were obtained with split N application. Applying selenate and ammonium-nitrate together after tillering increased the grain Se concentration, but did not affect the potential leaching of Se, and thus could be considered as an appropriate time of application of these elements.     

<Emphasis Type="Italic">Helianthus tuberosus</Emphasis> L. agg. in the Carpathian Basin: a blessing or a curse?

Helianthus tuberosus agg., an herbaceous perennial plant from the Asteraceae family, is native to North America and was introduced as a crop to Europe in the seventeenth century. The status of this plant has been rather controversial in the Carpathian Basin. This paper reviews its taxonomy, chorology, and ethnobotany in this region, using data obtained from herbarium specimens, ethnobotanical surveys performed in Transylvania, and data published earlier, documenting the invasive features of the plant since the beginning of the nineteenth century. Our results suggest that (1) Helianthus tuberosus agg. has been present in the Carpathian Basin from the nineteenth century, (2) its taxonomy is problematic since the first part of the nineteenth century; (3) ethnobotanical surveys confirmed that the plant’s tuber has been locally used mostly as a food in Transylvania, collected from cultivation. Overall, Helianthus tuberosus agg. is both a ‘blessing and a curse’ at the same time, it is a valuable crop with beneficial nutritional value, and also an environmentally dangerous invasive element for the diversity of the flora of the Carpathian Basin.     

Taurine does not improve the quality of short‐term stored rabbit spermatozoa in vitro

This study examines the impact of taurine on the viability, morphology and acrosome integrity of rabbit spermatozoa in vitro. Semen samples, obtained from four to five sexually mature and healthy New Zealand White rabbits, were pooled in heterospermic semen sample. This was divided and treated with taurine in a concentration of 0 (control), 1.5, 7, 12.5, 50 mM to a final concentration of 10⁸ spermatozoa/ml. The samples were then incubated at 37°C for 4 hr. A combination of fluorescent probes SYBR‐14/propidium iodide/PNA‐Alexa Fluor 647 was used to assess spermatozoa viability and acrosome integrity on a flow cytometer. The sperm morphology was evaluated under a light microscope following fixation in 1.5% paraformaldehyde. The experiment was repeated three times. According to the obtained results, the spermatozoa neither could have benefit from immediate taurine treatment, nor had they after 4‐hr incubation with respect to viability and acrosome integrity. Taurine did not initially alter the total and acrosome morphology of treated spermatozoa nor has it by 4 hr upon treatment. In conclusion, taurine may have no protective effect on the viability, morphology and acrosome integrity of short‐term stored rabbit spermatozoa.     

The effects of land‐use change on plant–soil–erosion relations,Nyereg Hill,Hungary

Vegetation of the Tihany Peninsula in Hungary has undergone serious changes caused by heavy trampling and overgrazing during the last century. In Tihany, the vegetation started to change towards anthropogenic associations. After grazing ceased, vegetation started to rearrange. There were no significant changes in species composition on trampled areas (on the ridge of the hill) between the examinations in 1994 and 2002. As a result of ceased grazing, the proportion of natural species was high in the grasslands of the S Nyereg Hill in 1994, while during the 2002 investigations, forest and scrub expanded at a rate that did not leave space for grassland on shallow soils and slope steppe (closing dry grasslands on hilly areas). The coverage of Elymus repens decreased, while Festuca species increased. The possible effects of plant‐cover change on soil loss were examined with the USLE (Universal Soil Loss Equation) model on the sloping areas. Eliminating harmful effects can decrease soil degradation, but the original state of soils can be restored only after a long period (hundreds of years). Further degradation of soils assists the expansion of drought‐resistant species and weeds in the associations. In 2007, soil‐thickness measurements and on‐site examinations were carried out to check the results of the former surveys and modeling.     

Effect of Free Manganese Activity on Yield and Uptake of Micronutrient Cations by Barley and Oat grown in Chelator-buffered Nutrient Solution

The uptake of micronutrient cations in relation to varying activities of Mn²⁺ was studied for barley (Hordeum vulgare L. var. Thule) and oat (Avena sativa L. var. Biri) grown in chelator buffered nutrient solution. Free activities of Mn²⁺ were calculated by using the chemical speciation programme GEOCHEM-PC. Manganese deficient conditions induced elevated concentrations of Zn and Fe in shoots of both species. The corresponding antagonistic relationship between Mn and Cu could only be seen in barley. The observed antagonistic relationships were only valid as long as the plant growth was limited by Mn deficiency. The Mn concentration in both plant species increased significantly with increasing Mn²⁺ activity in the nutrient solution. The concentration of Mn in the shoots of oat was higher than for barley except under severe Mn deficiency where it was found equal for both species. Manganese was accumulated in the roots of barley at high Mn²⁺ activity. The different shoot concentrations of Mn between barley and oat are therefore attributed to the extent of Mn translocation from roots to shoots. Manganese deficiency induced a significant increase in the shoot to root ratio in both species.     

管理肉种鸡的产蛋行为

法国和讲法语的北非国家是至今为止小体型、轻体重肉鸡的最大市场。许多法国种鸡育种公司正对这一需求作出反应,如肉鸡生产商Goasduff公司（一个管理出色的家族型企业,对他们的父母代鸡群定下了明确的目标）就拥有大部分小型种鸡。他们采取特殊的管理措施以取得合理的产蛋性能。