Screening for Fungicide Efficacy in Controlling Blackleg Disease in Wasabi (Eutrema japonicum).

Blackleg disease is devastating for wasabi (Eutrema japonicum) production, occurring at any time and everywhere within the main production area of the Sichuan Province, China. There have been very few studies on the chemical control of this disease. In this study, we isolated and identified a local popular strain of the pathogen Plenodomus wasabiae. The isolated fungus strain caused typical disease spots on the leaves and rhizomes upon inoculation back to wasabi seedlings. The symptoms of blackleg disease developed very quickly, becaming visible on the second day after exposure to P. wasabiae and leading to death within one week. We then evaluated the efficacy of ten widely used fungicides to screen out effective fungicides. The efficacy of the tested fungicides was determined through mycelial growth inhibition on medium plates. As a result, tebuconazole and pyraclostrobin were able to inhibit the mycelial growth of P. wasabiae, and the most widely used dimethomorph in local production areas produced the lowest inhibition activity (13.8%). Nevertheless, the highest control efficacy of tebuconazole and pyraclostrobin on wasabi seedlings was only 47.48% and 39.03%, respectively. Generally, the control efficacy of spraying the fungicide before inoculation was better than that after inoculation. An increase in the application concentration of the two fungicides did not proportionately result in improved performance. We cloned the full-length sequence of sterol 14-demethylase (CYP51) and cytochrome B (CYTB) of which the mutations may contribute to the possible antifungalresistance. These two genes of the isolated fungus do not possess any reported mutations that lead to fungicide resistance. Previous studies indicate that there is a significant difference between fungicides in terms of the effectiveness of controlling blackleg disease; however, the control efficacy of fungicides is limited in blackleg control. Therefore, field management to prevent wound infection and unfavorable environmental conditions are more important than pesticide management.

Lipid-Related Domestication Accounts for the Extreme Cold Sensitivity of Semiwild and Tropic Xishuangbanna Cucumber (Cucumis sativus L. var. xishuangbannanesis).

Xishuangbanna (XIS) cucumber (Cucumis sativus L. var. xishuangbannanesis) is a semiwild variety originating from low latitude tropic areas, and therefore shows extreme cold sensitivity and heat tolerance. Here, we mapped the quantitative trait loci (QTLs) that control the cold sensitivity and heat tolerance of XIS cucumber seedlings. Using bulked segregant analysis (BSA), we identified three QTLs (HTT1.1, HTT3.1, and HTT3.2, with a total length of 11.98 Mb) for heat tolerance and two QTLs (LTT6.1 and LTT6.2, with a total length of 8.74 Mb) for cold sensitivity. The QTL LTT6.1 was then narrowed down to a length of 641 kb by using kompetitive allele-specific PCR (KASP) markers. Based on structural variants (SVs) and single-nucleotide polymorphisms (SNPs), we found the LTT6.1 is covered by a high divergent region including a 50 kb deletion in the XIS49 genome, which affects the gene structure of lipase abhydrolase domain containing 6 (ABHD6, Csa_6G032560). Accordingly, there is a very big difference in lipid composition, but not in other osmoprotectants like free amino acids and fatty acids, between XIS49 and cultivated cucumber CL. Moreover, we calculated the composite likelihood ratio (CLR) and identified selective sweeps from 115 resequencing data, and found that lipid- and fatty-acid-related processes are major aspects in the domestication of the XIS group cucumber. LTT6.1 is a particularly special region positioned nearby lipid-related selective sweeps. These studies above suggested that the lipid-related domestication of XIS cucumbers should account for their extreme cold sensitivity.

Study on traces left on a mechanical lock picked by a 3D printed key in toolmarks examination.

The three-dimensional (3D) printed key is a key that can be manufactured from its virtual model by means of a 3D printer. This research focuses on the picking feasibilities and traces that can be observed and exploited from a forensic point of view after the picking of such type of keys. In this paper, 40 printed keys were manufactured using three different polymer materials (white resin, white nylon powder and black ABS). All the experiments were carried out under controlled conditions to allow the collections of data and traces produced by the picking. Of the 40 prints, only 38 picked the locks and the total picking ratio was 95 percent, meaning that a 3D printed key using polymer materials can be used to pick a lock. Elements of lock - pins and keyways - appeared to carry polymer materials (flakes or pieces) transferred from the prints during picking process. Additional, characteristic marks of a 3D printed key on the surface of pins was identical to those of an original key, but not similar to those of other picking tools. Indeed, this method could not create more marks on the bits of an original key while striations were left by the picking method using a duplicated key. Besides, FT-IR was a useful method of analyzing the type of polymer material used. When receiving original keys and a lock suspected to be picked in a crime scene, the toolmark examiners can quickly determine whether or not the lock was picked by a 3D printed key based on the examination results of these traces.

Poliovirus Detection and Genetic Characteristic from Sewage in Heilongjiang Province from 2013 to 2016.

By monitoring the sewage system in Heilongjiang province from 2013 to 2016, this study aimed to analyze the epidemiological tendency and genetic mutation of poliovirus (PV) found in the environment in order to setup a warning system for vaccine-derived poliovirus (VDPV) and the spread of wild poliovirus. In this study, we collected 139 sewage samples from 8 regions in Heilongjiang province. Poliovirus was identified from 72 samples, and the positivity rate was 51%. A total of 263 PV strains were isolated, including 22 strains of type 1 PV, 104 strains of type 2 PV, and 137 strains of type 3 PV. As a result of intratypic differentiation, using real-time PCR and nucleotide sequencing, 3 type 1 pre-VDPV, one type 2 VDPV, and 2 type 3 pre-VDPV strains were isolated. Interestingly, one type 1 strain with 5 nucleotide deletions and one type 3 recombinant on VP1 were isolated. By continuously monitoring the poliovirus in the environment, we aimed to recognize the VDPV or wild poliovirus with high neurovirulence from large-scale circulation and set up a warning system to avoid morbidity and virus transmission.

Multispectral palmprint recognition using a quaternion matrix.

Palmprints have been widely studied for biometric recognition for many years. Traditionally, a white light source is used for illumination. Recently, multispectral imaging has drawn attention because of its high recognition accuracy. Multispectral palmprint systems can provide more discriminant information under different illuminations in a short time, thus they can achieve better recognition accuracy. Previously, multispectral palmprint images were taken as a kind of multi-modal biometrics, and the fusion scheme on the image level or matching score level was used. However, some spectral information will be lost during image level or matching score level fusion. In this study, we propose a new method for multispectral images based on a quaternion model which could fully utilize the multispectral information. Firstly, multispectral palmprint images captured under red, green, blue and near-infrared (NIR) illuminations were represented by a quaternion matrix, then principal component analysis (PCA) and discrete wavelet transform (DWT) were applied respectively on the matrix to extract palmprint features. After that, Euclidean distance was used to measure the dissimilarity between different features. Finally, the sum of two distances and the nearest neighborhood classifier were employed for recognition decision. Experimental results showed that using the quaternion matrix can achieve a higher recognition rate. Given 3000 test samples from 500 palms, the recognition rate can be as high as 98.83%.