Genome-wide association study of pre-harvest sprouting tolerance using a 90K SNP array in common wheat (Triticum aestivum L.).

KEY MESSAGE: Three major loci for pre-harvest sprouting tolerance (PHST) were mapped on chromosomes 1AL, 3BS, and 6BL, and two CAPS and one dCAPS markers were validated. Sixteen lines with favorable alleles and increased PHST were identified. Pre-harvest sprouting (PHS) significantly affects wheat grain yield and quality. In the present study, the PHS tolerance (PHST) of 192 wheat varieties (lines) was evaluated by assessment of field sprouting, seed germination index, and period of dormancy in different environments. A high-density Illumina iSelect 90K SNP array was used to genotype the panel. A genome-wide association study (GWAS) based on single- and multi-locus mixed linear models was used to detect loci for PHST. The single-locus model identified 23 loci for PHST (P < 0.0001) and explained 6.0-18.9% of the phenotypic variance. Twenty loci were consistent with known quantitative trait loci (QTLs). Three single-nucleotide polymorphism markers closely linked with three major loci (Qphs.ahau-1A, Qphs.ahau-3B, and Qphs.ahau-6B) on chromosomes 1AL, 3BS, and 6BL, respectively, were converted to two cleaved amplified polymorphic sequences (CAPS) and one derived-CAPS markers, and validated in 374 wheat varieties (lines). The CAPS marker EX06323 for Qphs.ahau-6B co-segregated with a novel major QTL underlying PHST in a recombinant inbred line population raised from the cross Jing 411 × Wanxianbaimaizi. Linear regression showed a clear dependence of PHST on the number of favorable alleles. Sixteen varieties showing an elevated degree of PHST were identified and harbored more than 16 favorable alleles. The multi-locus model detected 39 marker-trait associations for PHST (P < 0.0001), of which five may be novel. Six loci common to the two models were identified. The combination of the two GWAS methods contributes to efficient dissection of the complex genetic mechanism of PHST.

Photodegradation of Vocs by C_TiO2 nanoparticles produced by flame CVD process.

Carbon containing C_TiO2 nanoparticles with rutile mass fractions about 20%, carbon mass fractions from 0-22%, having normal size distributions with mean sizes from 24-62 nm are synthesized by the oxidation of TiCl4 in industrial propane/air diffusion flame. Photodegradation of VOCs of formaldehyde, benzene, toluene and methanol by the C_TiO2 nanoparticles have been investigated by using a tubular photoreactor with C_TiO2 thin films coated on the wall of the tubular reactor by a sedimentation method. Effects of effective thickness of C_TiO2 thin films from 60-150 nm, relative humidity from 8-100%, and initial concentration of VOCs loaded air stream from 0.06-3 g/m3 on degradation degree have been investigated. Comparisons are made on degradation degree between the C_TiO2 nanoparticles and P25 photocatalyst and the results show that the photocatalytic activity of the C_TiO2 nanoparticles and P25 are comparative.

Efficient Mineralization of Toluene by W-Doped TiO2 Nanofibers Under Visible Light Irradiation.

Toxic toluene gas caused enormous harm to human health, and the traditional method to deal with this puzzle is using physical adsorption, which just transfer the toluene from one medium to another. Photocatalysis has great potential to mineralize toluene into CO2 under visible light irradiation, but their applications have been limited by difficulties in preparing efficient photocatalysts with fine crystallite size, considerable visible light response, and large surface area to contact with toluene gas. To address this problem, we have developed a film composed of W-doped TiO2 nanofibers to mineralize toluene under visible light irradiation. The electrospinning preparation route allows incorporation of up to 50 wt% of W in substitutional positions of titanium atom in the anatase network. The W-doped TiO2 nanofibers behave finer crystallite size, stronger visible light absorbance, and larger surface area comparing with pure TiO2 nanofibers. The nanofiber structured morphology on the quartz tube promotes the reaction rates for the gas-phase photo-oxidation of toluene. The concentrations of the produced CO2 keep steady during the photodegradation process, indicating the practicality and operability for the whole experiment. This research is conducive to the development of novel photocatalytic materials to efficiently mineralize toxic gas pollutants including toluene for practical application.