The effect of concurrent elevation in CO2 and temperature on the growth, photosynthesis, and yield of potato crops.

Global climate change accompanied by continuous increases in atmospheric carbon dioxide (CO2) concentration and temperature affects the growth and yield of important crops. The present study investigated the effect of elevated temperature and CO2 concentrations on the growth, yield, and photosynthesis of potato (Solanum tuberosum L. cv. Superior) crops using Korean Soil-Plant-Atmosphere-Research chambers that allow the regulation of temperature and CO2 concentration under daylight conditions. Based on the average temperature from 1991 to 2010 in the Jeonju area, South Korea, potato plants were exposed to four different conditions: ambient weather (400 µmol mol-1, aCaT), elevated temperature (+4°C, aCeT), elevated CO2 concentration (800 µmol mol-1, eCaT), and concurrently elevated CO2 concentration and temperature (eCeT). Under aCeT conditions, the temperature exceeded the optimal growth temperature range towards the late growth phase that decreased stomatal conductance and canopy net photosynthetic rate and subsequently reduced biomass and tuber yield. Stomatal conductance and chlorophyll concentration were lower under eCaT conditions than under aCaT conditions, whereas late-growth phase biomass and tuber yield were greater. Compared to other conditions, eCeT yielded a distinct increase in growth and development and canopy net photosynthetic rate during tuber initiation and bulking. Consequently, biomass and canopy net photosynthesis increased, and tuber yield increased by 20.3%, which could be attributed to the increased tuber size, rather than increased tuber number. Elevated CO2 reduced chlorophyll, magnesium, and phosphorus concentrations; reducing nitrogen concentration (by approximately 39.7%) increased the C:N ratio. The data indicate that future climate conditions will likely change nutrient concentration and quality of crops. The present study shows that while elevated temperature may negatively influence the growth and yield of potato crops, especially towards the late-growth phase, the concurrent and appropriate elevation of CO2 and temperature could promote balanced development of source and sink organs and positively effect potato productivity and quality.

Enhancement in the microstructure and photoluminescence properties of YVO4:Eu3+ by Al doping.

Al contents have been doped as a sensitizer to improve the luminescent brightness, and the conventional solid state reaction method has been used to synthesize the phosphors. Al doping effects on the microstructures of YVO4:Eu3+ phosphors were measured by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The luminescent characteristics were characterized by photoluminescence excitation (PLE) and emission (PL) measurements. Incorporation of Al3+ ions into the YVO4:Eu phosphors has greatly enhanced the crystallinity, particle size and hence the luminescence properties and the optimum concentration in Al dopants are found to be 0.05 mol. The photoluminescence intensity of 0.05 mol Al(3+)-doped YVO4:Eu3+ phosphors was improved by a factor of 1.41, in comparison with undoped Y0.95Eu0.05VO4 phosphor. The improvement in photoluminescence properties with Al doping may result from the improved crystallinity and from the enlarged grain sizes inducing lower scattering loss.

Phylogenetic Relationship in Different Commercial Strains of Pleurotus nebrodensis Based on ITS Sequence and RAPD.

The molecular phylogeny in nine different commercial cultivated strains of Pleurotus nebrodensis was studied based on their internal transcribed spacer (ITS) region and RAPD. In the sequence of ITS region of selected strains, it was revealed that the total length ranged from 592 to 614 bp. The size of ITS1 and ITS2 regions varied among the strains from 219 to 228 bp and 211 to 229 bp, respectively. The sequence of ITS2 was more variable than ITS1 and the region of 5.8S sequences were identical. Phylogenetic tree of the ITS region sequences indicated that selected strains were classified into five clusters. The reciprocal homologies of the ITS region sequences ranged from 99 to 100%. The strains were also analyzed by RAPD with 20 arbitrary primers. Twelve primers were efficient to applying amplification of the genomic DNA. The sizes of the polymorphic fragments obtained were in the range of 200 to 2000 bp. RAPD and ITS analysis techniques were able to detect genetic variation among the tested strains. Experimental results suggested that IUM-1381, IUM-3914, IUM-1495 and AY-581431 strains were genetically very similar. Therefore, all IUM and NCBI gene bank strains of P. nebrodensis were genetically same with some variations.