ABSTRACT
The widespread use of Ag3PO4 is not surprising when considering its higher photostability compared to other silver-based materials. The present work deals with the facile precipitation method of silver phosphate. The effects of four different phosphate sources (H3PO4, NaH2PO4, Na2HPO4, Na3PO4·12 H2O) and two different initial concentrations (0.1 M and 0.2 M) were investigated. As the basicity of different phosphate sources influences the purity of Ag3PO4, different products were obtained. Using H3PO4 did not lead to the formation of Ag3PO4, while applying NaH2PO4 resulted in Ag3PO4 and a low amount of pyrophosphate. The morphological and structural properties of the obtained samples were studied by X-ray diffractometry, diffuse reflectance spectroscopy, scanning electron microscopy, infrared spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activity of the materials and the corresponding reaction kinetics were evaluated by the degradation of methyl orange (MO) under visible light. Their stability was investigated by reusability tests, photoluminescence measurements, and the recharacterization after degradation. The effect of as-deposited Ag nanoparticles was also highlighted on the photostability and the reusability of Ag3PO4. Although the deposited Ag nanoparticles suppressed the formation of holes and reduced the degradation of methyl orange, they did not reduce the performance of the photocatalyst.
ABSTRACT
Tomato spotted wilt virus (TSWV) occurs worldwide and causes production losses in many important horticultural crops such as tomato and pepper. Breeding resistant cultivars has been the most successful method so far for TSWV disease control, but only two genes have been found to confer resistance against a wide spectrum of TSWV isolates: Sw-5 in tomato and Tsw in pepper. However, TSWV resistance-breaking isolates have emerged in different countries a few years after using resistant cultivars. In this paper, we report the first complete nucleotide sequences of three Spanish TSWV isolates with different biotypes according to their abilities to overcome resistance: LL-N.05 (wild type, WT), Pujol1TL3 (Sw-5 resistance breaking, SBR) and PVR (Tsw resistance-breaking, TBR). The genome of these TSWV isolates consisted of three segments: L (8913-8914 nt), M (4752-4825 nt) and (S 2924-2961 nt). Variations in nucleotide sequences and genomic RNA lengths among the different virus biotypes are reported here. Phylogenetic analysis of the five TSWV open reading frames showed evidence of reassortment between genomic segments of LL-N.05 and Pujol1TL3, which was supported by analysis with different recombination-detecting algorithms.
Subject(s)
Plant Diseases/virology , Solanum lycopersicum/virology , Tospovirus/genetics , Tospovirus/isolation & purification , Base Sequence , Capsicum/virology , Genome, Viral , Lactuca/virology , Molecular Sequence Data , Phylogeny , Spain , Tospovirus/classificationABSTRACT
Tomato torrado virus (ToTV) causes serious damage to the tomato industry and significant economic losses. A quantitative real-time reverse-transcription polymerase chain reaction (RT-qPCR) method using primers and a specific TaqMan(®) MGB probe for ToTV was developed for sensitive detection and quantitation of different ToTV isolates. A standard curve using RNA transcripts enabled absolute quantitation, with a dynamic range from 10(4) to 10(10) ToTV RNA copies/ng of total RNA. The specificity of the RT-qPCR was tested with twenty-three ToTV isolates from tomato (Solanum lycopersicum L.), and black nightshade (Solanum nigrum L.) collected in Spain, Australia, Hungary and France, which covered the genetic variation range of this virus. This new RT-qPCR assay enables a reproducible, sensitive and specific detection and quantitation of ToTV, which can be a valuable tool in disease management programs and epidemiological studies.
