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The grasslands in North China are rich in fungal resources. However, the knowledge of the structure and function of fungal communities and the role of microbial communities in vegetation restoration and succession are limited. Thus, we used an Illumina HiSeq PE250 high-throughput sequencing platform to study the changing characteristics of soil fungal communities in degraded grasslands, which were categorized as non-degraded (ND), lightly degraded, moderately degraded, and severely degraded (SD). Moreover, a correlation analysis between soil physical and chemical properties and fungal communities was completed. The results showed that the number of plant species, vegetation coverage, aboveground biomass, and diversity index decreased significantly with increasing degradation, and there were significant differences in the physical and chemical properties of the soil among the different degraded grasslands. The dominant fungal phyla in the degraded grassland were as follows: Ascomycota, 44.88%–65.03%; Basidiomycota, 12.68%–29.91%; and unclassified, 5.51%–16.91%. The dominant fungi were as follows: Mortierella, 6.50%–11.41%; Chaetomium, 6.71%–11.58%; others, 25.95%–36.14%; and unclassified, 25.56%–53.0%. There were significant differences in the microbial Shannon–Wiener and Chao1 indices between the ND and degraded meadows, and the composition and diversity of the soil fungal community differed significantly as the meadows continued to deteriorate. The results showed that pH was the most critical factor affecting soil microbial and fungal communities in SD grasslands, whereas soil microbial and fungal communities in ND grasslands were mainly affected by water content and other environmental factors. [ABSTRACT FROM AUTHOR]

Although numerous studies have linked asthma to air temperature and pollution, few studies have examined their interactive effects on asthma outpatient visits. This study investigated how air pollutants and their interactions with temperature affect asthma outpatient visits in a city in northern Chinaduring the time period 2018 - 2020.. As the results, 24,163 asthma outpatients were recorded, a 10-μg/m3 increase in PM10, PM2.5, SO2, and NO2 concentrations was associated with significant increases in visits of 3.47% (95% CI: 2.35%–4.60%), 0.83% (95% CI: 0.36%–1.30%), 3.17% (95% CI: 1.47%–4.90%), and 8.90% (95% CI: 6.09%–11.79%), respectively. The effect was stronger in females than males, and stronger in the elderly (≥65 years) than among the young. The interaction between low temperatures and high air pollution levels significantly increased the number of asthma outpatient visits. This study emphasizesthe importance of reducing air pollution in order to lessen the effects of cold. [ABSTRACT FROM AUTHOR]

Red mud (RM) is a solid waste material with high alkalinity and low cementing activity component. The low activity of RM makes it difficult to prepare high-performance cementitious materials from RM alone. Five groups of RM-based cementitious samples were prepared by adding steel slag (SS), grade 42.5 ordinary Portland cement (OPC), blast furnace slag cement (BFSC), flue gas desulfurization gypsum (FGDG), and fly ash (FA). The effects of different solid waste additives on the hydration mechanisms, mechanical properties, and environmental safety of RM-based cementitious materials were discussed and analyzed. The results showed that the samples prepared from different solid waste materials and RM formed similar hydration products, and the main products were C–S–H, tobermorite, and Ca(OH)2. The mechanical properties of the samples met the single flexural strength criterion (≥ 3.0 MPa) for first-grade pavement brick in the Industry Standard of Building Materials of the People's Republic of China-Concrete Pavement Brick. The alkali substances in the samples existed stably, and the leaching concentrations of the heavy metals reached class III of the surface water environmental quality standards. The radioactivity level was in the unrestricted range for main building materials and decorative materials. The results manifest that RM-based cementitious materials have the characteristics of environmentally friendly materials and possess the potential to partially or fully replace traditional cement in the development of engineering and construction applications and it provides innovative guidance for combined utilization of multi-solid waste materials and RM resources. [ABSTRACT FROM AUTHOR]

On March 11, 2011, a serious radionuclide leakage accident occurred at Fukushima Daiichi nuclear power plant, and a large number of radionuclides were released, causing serious pollution to the ocean environment. On August 25, 2021, Japan announced the overall plan for the discharge of radioactive sewage from the Fukushima Daiichi nuclear power plant into the ocean, and the discharge will begin around the spring of 2023. All operational and under-construction nuclear power plants in China are distributed in coastal areas presently. In case of a nuclear leakage accident, radionuclides will diffuse through the ocean and pollute the ecological environment. The study of radionuclide diffusion mechanism in the ocean and emergency response plays an important role in accident mitigation under oceanic radioactive events. A radionuclide diffusion model in the ocean was established and the radionuclide diffusion mechanism in the ocean was analyzed. And then a prediction and monitoring system of radionuclide diffusion in the ocean was proposed. The results show that the short-term radionuclide diffusion is mainly influenced by the source term, flow field and decay of 131I, and the degree of influence decreases in turn. On the whole, influences of the flow field and 131I decay are weakened during the long-term diffusion. At the same time, the influence of 137Cs decay begins to be obvious and the influence of suspended matter is increasing. The influence of ocean organisms is always small. Problems of scientific prediction and protection were analyzed, and the emergency response scheme was given. It is of great significance to improve the capacity of emergency response for oceanic radioactive events. [ABSTRACT FROM AUTHOR]

SUMMARY: Cold stress at the reproductive stage severely affects the production and geographic distribution of rice. The Geng/japonica subpopulation gradually developed stronger cold adaptation than the Xian/indica subpopulation during the long‐term domestication of cultivated rice. However, the evolutionary path and natural alleles underlying the cold adaptability of intra‐Geng subspecies remain largely unknown. Here, we identified MITOGEN‐ACTIVATED PROTEIN KINASE 3 (OsMAPK3) and LATE EMBRYOGENESIS ABUNDANT PROTEIN 9 (OsLEA9) as two important regulators for the cold adaptation of Geng subspecies from a combination of transcriptome analysis and genome‐wide association study. Transgenic validation showed that OsMAPK3 and OsLEA9 confer cold tolerance at the reproductive stage. Selection and evolution analysis suggested that the Geng version of OsMAPK3 (OsMAPK3Geng) directly evolved from Chinese Oryza rufipogon III and was largely retained in high‐latitude and high‐altitude regions with low temperatures during domestication. Later, the functional nucleotide polymorphism (FNP‐776) in the Kunmingxiaobaigu and Lijiangxiaoheigu version of the OsLEA9 (OsLEA9KL) promoter originated from novel variation of intra‐Geng was selected and predominantly retained in temperate Geng to improve the adaptation of Geng together with OsMAPK3Geng to colder climatic conditions in high‐latitude areas. Breeding potential analysis suggested that pyramiding of OsMAPK3Geng and OsLEA9KL enhanced the cold tolerance of Geng and promotes the expansion of cultivated rice to colder regions. This study not only highlights the evolutionary path taken by the cold‐adaptive differentiation of intra‐Geng, but also provides new genetic resources for rice molecular breeding in low‐temperature areas. Significance Statement: In this study, we identified variants in the two genes, OsMAPK3 and OsLEA9, as conferring cold tolerance of the Geng subspecies at the reproductive stage. OsMAPK3Geng originated from Chinese Oryza rufipogon III before following two evolutionary routes during domestication. It first genetically interacts with an allele of OsLEA9KL, which harbors a novel polymorphism in its promoter in Geng, to improve jointly the cold adaptability of Geng and promote its expansion to high‐altitude regions with a colder climate. In parallel, variation in OsMAPK3Geng sequentially move northward and enhance the tolerance of Geng to lower temperatures, eventually promoting the planting of Geng in higher‐latitude areas such as northeast China. Our results provide insights into the evolutionary path of cold tolerance genes underlying the cold adaptation of intra‐Geng and provide new genetic resources for rice molecular breeding for cold tolerance. [ABSTRACT FROM AUTHOR]

Indica is not only an important rice subspecies widely planted in Asia and the rest of the world, but it is also the genetic background of the majority of hybrid varieties in China. Studies on genetic structure and genetic diversity in indica germplasm resources are important for the classification and utilization of cultivated rice in China. Using a genetically representative core collection comprising 1482 Chinese indica landraces, we analysed the genetic structure, geographic differentiation and diversity. Model-based structure analysis of varieties within three ecotypes revealed nine eco-geographical types partially accordant with certain ecological zones in China. Differentiation of eco-geographical types was attributed to local ecological adaption and physical isolation. These groups may be useful for developing heterotic groups of indica. To facilitate the identification of different ecotypes and eco-geographical types, we identified characteristic SSR alleles of each ecotype and eco-geographical type and a rapid index of discrimination based on characteristic alleles. The characteristic alleles and rapid discrimination index may guide development of heterotic groups, and selection of hybrid parents. [ABSTRACT FROM AUTHOR]

The extent of and accessibility to genetic variation in a large germplasm collection are of interest to biologists and breeders. Construction of core collections (CC) is a favored approach to efficient exploration and conservation of novel variation in genetic resources. Using 4,310 Chinese accessions of Oryza sativa L. and 36 SSR markers, we investigated the genetic variation in different sized sub-populations, the factors that affect CC size and different sampling strategies in establishing CC. Our results indicated that a mathematical model could reliably simulate the relationship between genetic variation and population size and thus predict the variation in large germplasm collections using randomly sampled populations of 700-1,500 accessions. We recommend two principles in determining the CC size: (1) compromising between genetic variation and genetic redundancy and (2) retaining the main types of alleles. Based on the most effective scheme selected from 229 sampling schemes, we finally developed a hierarchical CC system, in which different population scales and genetic diversities allow a flexible use of genetic resources. The CC, comprising 1.7% (932) of the accessions in the basic collection, retained more than 85% of both the SSR and phenotypic variations. A mini core collection, comprising 0.3% (189) of the accessions in the basic collection, retained 70.65% of the SSR variation and 76.97% of the phenotypic variation, thus providing a rational framework for intensive surveys of natural variation in complex traits in rice genetic resources and hence utilization of variation in rice breeding. [ABSTRACT FROM AUTHOR]

Using 36 SSR markers and 889 accessions of common wild rice in China, the genetic diversity and the divergence among different geographical populations are investigated. Guangdong Province has the largest number of alleles, which account for 84% of the total alleles detected in the study, followed by Guangxi Province. The Nei's gene diversity indices, from high to low, are in the sequence of Hainan, Guangdong, Guangxi, Fujian, Hunan, Jiangxi, and Yunnan provinces. Two genetic diversity centers of Chinese common wild rice are detected on the basis of geographic analysis, i.e., the region covering Boluo, Zijin, Lufeng, Haifeng, Huidong and Huiyang counties of Guangdong Province and the region covering Yongning, Longan, Laibin and Guigang counties of Guangxi Province. The common wild rice in Yunnan, Hunan, Jiangxi, and Fujian provinces are diverged into respectively independent populations with relatively large genetic distances, whereas, those in Hainan, Guangdong and Guangxi provinces have relatively low genetic divergence. Under the condition of geographic separation, natural selection is considered as one of the primary forces contributing to the divergence of common wild rice in China. [ABSTRACT FROM AUTHOR]

Preserving many kinds of rice resources and rich variations, Guizhou Province is one of the districts with the highest genetic diversity of cultivated rice (Oryza sativa L.) in China. In the current research, genetic diversity and structure of 537 accessions of cultivated rice from Guizhou were studied using 36 microsatellite markers and 39 phenotypic characters. The results showed that the model-based genetic structure was the same as genetic-distance-based one using SSRs but somewhat different from the documented classification (mainly based on phenotype) of two subspecies. The accessions being classified into indica by phenotype but japonica by genetic structure were much more than that being classified into japonica by phenotype but indica by genetic structure. Like Ding Ying's taxonomic system of cultivated rice, the subspecific differentiation was the most distinct differentiation within cultivated rice. But the differentiation within indica or japonica population was different: japonica presented clearer differentiation between soil-watery ecotypes than indica, and indica presented clearer differentiation between seasonal ecotypes than japonica. Cultivated rices in Guizhou revealed high genetic diversity at both DNA and phenotypic levels. Possessing the highest genetic diversity and all the necessary conditions as a center of genetic diversity, region Southwestern of Guizhou was .,suggested as the center of genetic diversity of O. sativa L. from Guizhou. [ABSTRACT FROM AUTHOR]

To Understand geographical distribution of the genetic diversity of rice cultivars (Oryza sativa L.) and its trends in recent fifty years in China, 453 accessions were analyzed by 36 microsatellites loci and 42 phenotypic traits. Results revealed that the genetic diversity by SSRs is highly consistent with that by phenotypic traits and the genetic diversity of indica cultivars was higher than that of japonica cultivars; the genetic diversity of cultivars declined from 1950s to 1980s and then increased greatly; among the six rice ecological zones (REZs), genetic diversity of REZII was the highest and those of REZV and REZVI were the lowest at both DNA and phenotypic level. Jiangsu and Jiangxi provinces in the middle and lower reaches of Yangtze River and Sichuan province in southwest of China were the areas with the highest genetic diversity. Breeders in REZV which is an important japonica rice area but with very low genetic diversity should explore more gene resources to widen the genetic backgrounds of cultivars. [ABSTRACT FROM AUTHOR]

• A model for calculating radionuclide dispersion in the ocean is established. • Its credibility is verified by both experiments and a fuzzy evaluation method. • The predicted temperature and salinity distribution in the Yellow sea are reasonable. • The migration path of radionuclides in China's coastal ocean conforms to the experiment. The credibility of a calculation model of radionuclide dispersion in the ocean determines the degree of trust that developers and users place in it. In this paper, ocean experiments are conducted to verify the credibility of the established model after a nuclear leakage accident. The model is then used for predictive calculations of the dispersion and migration of radionuclides in the ocean, and a method is proposed to evaluate its credibility. The results show that the temperature and salinity of the bottom layer of the Yellow Sea calculated by the established calculation model well portray its warm current under real conditions. The hydrodynamic results adequately describe the tidal phenomena in coastal waters and are in good agreement with the seabed base measurements. Through an ocean buoy experiment, it was found that the migration path of a buoy matched well with the simulated migration path of radionuclides. The difference between simulation and experiment in direction was 4.3°, and the distance error was 0.38 km. In winter, the migration path of radionuclides in the ocean always advances in rotation. In the deposition of radionuclides into the ocean through the atmosphere, they mainly disperse back and forth. With increasing time, radionuclides migrate and disperse to the southeast under the influence of tidal and north winds. The credibility evaluation of the calculation model is High (H) using the established fuzzy comprehensive evaluation, analytic hierarchy process and adaptive neuro-fuzzy inference system (fuzzy AHP-ANFIS) method, and the credibility of the results of the established computational model is verified. [ABSTRACT FROM AUTHOR]

Objective: Preterm birth (PTB) is considered as a public health problem and one of the main risk factors related to the global disease burden. The purpose of this study aims to explore the influence of exposure to major air pollutants at different pregnancies on PTB. Methods: The relationship between air pollutants and PTB in China was collected from cohort studies and case-control studies published before 30 April 2022. Meta-analysis was carried out with STATA 15.0 software. Results: A total of 2,115 papers were retrieved, of which 18 papers met the inclusion criteria. The comprehensive effect of pollutant exposure and PTB were calculated. PM 2.5 during entire pregnancy and O 3 exposure during third trimester were positively associated with preterm birth. Every 10 μg/m 3 increase in the average concentration of PM 2.5 during the whole pregnancy will increase the risk of premature delivery by 4%, and every 10 μg/m 3 increase in the average concentration of O 3 in the third trimester will increase the risk of premature delivery by 1%. Conclusion: Exposure to PM 2.5 entire prenatal pregnancy and O 3 in third trimester is associated with an increased risk of preterm birth occurrence., Competing Interests: The authors declare that they do not have any conflicts of interest., (Copyright © 2023 Wang, Wang, Gao, Xu, Li, Liu, Li, Xia and Fang.)

The improvement of cold adaptation has contributed to the increased growing area of rice. Standing variation and de novo mutation are distinct natural sources of beneficial alleles in plant adaptation. However, the genetic mechanisms and evolutionary patterns underlying these sources in a single population during crop domestication remain elusive. Here we cloned the CTB2 gene, encoding a UDP-glucose sterol glucosyltransferase, for cold tolerance in rice at the booting stage. A single standing variation (I408V) in the conserved UDPGT domain of CTB2 originated from Chinese Oryza rufipogon and contributed to the cold adaptation of Oryza sativa ssp. japonica. CTB2 is located in a 56.8 kb region, including the previously reported gene CTB4a in which de novo mutation arose c. 3200 yr BP in Yunnan province, China, conferring cold tolerance. Standing variation of CTB2 and de novo mutation of CTB4a underwent stepwise selection to facilitate cold adaptation to expand rice cultivation from high-altitude to high-latitude regions. These results provide an example of stepwise selection on two kinds of variation and describe a new molecular mechanism of cold adaptation in japonica rice., (© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation.)

The extent of and accessibility to genetic variation in a large germplasm collection are of interest to biologists and breeders. Construction of core collections (CC) is a favored approach to efficient exploration and conservation of novel variation in genetic resources. Using 4,310 Chinese accessions of Oryza sativa L. and 36 SSR markers, we investigated the genetic variation in different sized sub-populations, the factors that affect CC size and different sampling strategies in establishing CC. Our results indicated that a mathematical model could reliably simulate the relationship between genetic variation and population size and thus predict the variation in large germplasm collections using randomly sampled populations of 700-1,500 accessions. We recommend two principles in determining the CC size: (1) compromising between genetic variation and genetic redundancy and (2) retaining the main types of alleles. Based on the most effective scheme selected from 229 sampling schemes, we finally developed a hierarchical CC system, in which different population scales and genetic diversities allow a flexible use of genetic resources. The CC, comprising 1.7% (932) of the accessions in the basic collection, retained more than 85% of both the SSR and phenotypic variations. A mini core collection, comprising 0.3% (189) of the accessions in the basic collection, retained 70.65% of the SSR variation and 76.97% of the phenotypic variation, thus providing a rational framework for intensive surveys of natural variation in complex traits in rice genetic resources and hence utilization of variation in rice breeding.

China is one of the largest centers of genetic diversity of Oryza sativa L. in the world. Using a genetically representative primary core collection of 3,024 rice landraces in China, we analyzed the genetic structure and intraspecific differentiation of O. sativa, and the directional evolution of SSR. The genetic structure was investigated by model-based structure analysis and construction of neighbor-joining phylogenetic tree. Comparison between genetic structure and predefined populations according to Ting's taxonomic system revealed a hierarchical genetic structure: two distinct subspecies, each with three ecotypes and different numbers of geo-ecogroups within each ecotype. Two subspecies evidently resulted from adaptation to different environments. The different cropping systems imposed on the subspecies led to further differentiation, but the variation within each subspecies resulted from different causes. Indica, under tropical-like or lowland-like environments, exhibited clear differentiation among seasonal ecotypes, but not among soil-watery ecotypes; and japonica showed clear differences between soil water regime ecotypes, but not among seasonal ecotypes. Chinese cultivated rice took on evident directional evolution in microsatellite allele size at several aspects, such as subspecies and geographical populations. Japonica has smaller allele sizes than indica, and this may partly be the result of their different domestication times. Allele size was also negatively correlated with latitude and altitude, and this may be interpreted by different mutation rates, selection pressures, and population size effects under different environments and cropping systems.

Yunnan Province is one of the largest centers of genetic diversity of Oryza sativa L. in China, and in the world. Using a genetically representative core collection of 692 rice landraces from Yunnan, the genetic structure, differentiation, and geographic diversity of this rice germplasm were analyzed. The accessions were classified into different populations, according to the model-based structure analysis. Model-based populations were characterized through the reconstruction of a neighbor-joining tree, principal coordinate analysis, and the estimation of morphologic and SSR variations. Finally, the distribution of genetic diversity and differentiation among districts were studied. Seven model-based populations were identified on the basis of the structure analysis. This classification was partly consistent with Ting's 5-level taxonomic system. Differentiation between 2 rice subspecies is the most apparent, with a clearer differentiation between soil-watery ecotypes in japonica than in indica; however, differentiation among seasonal ecotypes in indica is clearer than in japonica. Cropping system and man-made restricted-growth environments could be considered to be the main forces driving the intraspecific differentiation of cultivated rice. It has been suggested that, because it possesses the highest genetic diversity and all the necessary conditions as a center of genetic diversity, the southwest region of Yunnan, encompassing Simao, Lincang, and Xishuangbanna districts, is the center of genetic diversity of Yunnan rice landraces.