普劳螨属一新种记述（蜱螨亚纲：巨须螨科）

本文记述普劳螨属一新种:宽颚普劳螨Pulaeus platygnathus sp.nov.,并与近似种马丁普劳螨Pulaeus martini Den Heyer,1981进行了比较。     

Use of molecular DNA probes in the diagnosis of mucoviscidosis-- analysis of restriction fragment length polymorphisms (RFLP) in 22 high-risk families]

The results of DNA analysis with the aid of specific molecular probes are discussed. DNA analysis involved 22 families of a high risk of cystic fibrosis. A significance of the obtained results in genetic counselling is also discussed. DNA analysis enabled detection or exclusion of cystic fibrosis gene carrier state in patient's relatives. DNA analysis proved fully informative in case of 17 families being a base to offer these families prenatal diagnosis of the disease in the I trimester of pregnancy, if such a family plans conception, and to accept this diagnostic technique.     

Digital scanning-integrating cytospectrophotometer]

A principal scheme of the digital scanning and intergrating cytospectrophotometer is described which permits to measure the integrating optical density of specifically stained preparations, "spot" optical density of any absorbing preparations and the area of absorbing objects in two different levels of absorbtion.     

Enhanced Rate Capability of Ion‐Accessible Ti3C2Tx‐NbN Hybrid Electrodes

Although 2D Ti₃C₂T_x is a good candidate for supercapacitors, the restacking of nanosheets hinders the ion transport significantly at high scan rates, especially under practical mass loading (>10 mg cm^?2) and thickness (tens of microns). Here, Ti₃C₂T_x‐NbN hybrid film is designed by self‐assembling Ti₃C₂T_x with 2D arrays of NbN nanocrystals. Working as an interlayer spacer of Ti₃C₂T_x, NbN facilitates the ion penetration through its 2D porous structure; even at extremely high scan rates. The hybrid film shows a thickness‐independent rate performance (almost the same rate capabilities from 2 to 20 000 mV s^?1) for 3 and 50 µm thick electrodes. Even a 109 µm thick Ti₃C₂T_x‐NbN electrode shows a better rate performance than 25 µm thick pure Ti₃C₂T_x electrodes. This method may pave a way to controlling ion transport in electrodes composed of 2D conductive materials, which have potential applications in high‐rate energy storage and beyond.     

Surprising low diversity of the plant pathogen Phytophthora in Amazonian forests

The genus Phytophthora represents a group of plant pathogens with broad global distribution. The majority of them cause the collar and root-rot of diverse plant species. Little is known about Phytophthora communities in forest ecosystems, especially in the Neotropical forests where natural enemies could maintain the huge plant diversity via negative density dependence. We characterized the diversity of soil-borne Phytophthora communities in the North French Guiana rainforest and investigated how they are structured by host identity and environmental factors. In this little-explored habitat, 250 soil cores were sampled from 10 plots hosting 10 different plant families across three forest environments (Terra Firme, Seasonally Flooded and White Sand). Phytophthora diversity was studied using a baiting approach and metabarcoding (High-Throughput Sequencing) on environmental DNA extracted from both soil samples and baiting-leaves. These three approaches revealed very similar communities, characterized by an unexpected low diversity of Phytophthora species, with the dominance of two cryptic species close to Phytophthora heveae. As expected, the Phytophthora community composition of the French Guiana rainforest was significantly impacted by the host plant family and environment. However, these plant pathogen communities are very small and are dominated by generalist species, questioning their potential roles as drivers of plant diversity in these Amazonian forests.     

Lead soaps formation and biodiversity in a XVIII Century wax seal coloured with minium

A multidisciplinary approach was carried out in order to study the biodeterioration and the associated microbiome of a XVIII Century wax seal coloured with minium. A small wax seal fragment was observed by scanning electron microscopy combined with energy dispersive spectroscopy in non-destructive mode. The same object was analysed by Raman and Fourier-transform infrared spectroscopy. The identification of the microbiota growing on the seal was performed with both a culture-dependent strategy, combined with hydrolytic assays, and high-throughput sequencing using the MinION platform. The whole bacterial 16S rRNA gene and the fungal markers ITS and 28S rRNA were targeted. It was observed that the carnauba wax coloured with lead tetroxide (minium) was covered by a biofilm consisting of a network of filaments and other structures of microbial origin. The culture-dependent and culture-independent investigations showed the presence of a complex microbiota composed mainly by fungal members, which demonstrated interesting properties related to lipids and lead processing. The formation of lead soaps and secondary biogenic minerals was also described.     

Genome-wide analysis of ACO and ACS genes in pear (Pyrus ussuriensis)

The “Nanguo” pear is a typically climacteric fruit and ethylene is the main factor controlling the ripening process of climacteric fruit. Ethylene biosynthesis has been studied clearly and ACC synthase (ACS) is the rate-limited enzyme. ACO (ACC oxidase) is another important enzyme in ethylene biosynthesis. By exploring the pear genome, we identified 13 ACS genes and 11 ACO genes, respectively, and their expression patterns in fruit and other organs were investigated. Among these genes, 11 ACS and 8ACO genes were expressed in pear fruits. What’s more, 4 ACS and 3ACO genes could be induced by Ethephon and inhibited by 1-MCP treatment. This study is the first time to explore ACS and ACO genes at genome-wide level and will provide new data for research on pear fruit ripening.

     

香椿种质生长及叶部表型性状的遗传变异分析

以84个香椿(Toona sinensis(A.Juss.)Roem.)种质为材料,对其2个生长性状和18个叶部性状(包含6个质量性状和12个数量性状)进行测定。结果显示,香椿6个叶部质量性状变异类型丰富,呈现出多态化特点,单一性状的主要表型多为1~2个。苗高、地径及叶部表型等14个数量性状在种质间的差异均达到极显著水平,且除地径外,其他性状的遗传方差分量均大于环境方差分量,表明此类性状主要受遗传控制。参试的14个数量性状的平均表型变异系数为20.35%,平均遗传变异系数为16.36%;综合表型和遗传变异系数,叶柄长度较其他性状变异大,而叶片夹角稳定性最高,各数量性状(除地径外)遗传变异系数与表型变异系数之差小于7%。香椿种质各性状间Shannon-Weaver遗传多样性指数相差不大(1.892~2.069),遗传多样性水平高,具有良好的遗传改良基础。聚类分析可将84个香椿种质分为5类,类群Ⅰ表现为生长旺盛、小比叶重型;类群Ⅱ生长较快、叶片较大;类群Ⅲ种质数量最多,属生长缓慢、大比叶重型;类群Ⅳ特征为大叶片、多叶型;类群Ⅴ为小叶片、稀叶型。研究结果表明参试香椿种质变异丰富,遗传多样性水平高,能为良种选育、遗传改良等研究提供丰富的遗传材料。