Ecological Regions Of China Research Articles

Plant Consumption by Early-Middle Neolithic Peoples in Guangxi, South China: Archaeobotanical Evidence From the Dingsishan Site

The Dingsishan Site, located in Nanning City, Guangxi Zhuang Autonomous Region, is one of the most important Neolithic archaeological sites in the Lingnan region of China’s southeastern seaboard. Plant microfossil remains recovered from excavated artifacts and human teeth suggest that the site’s ancient inhabitants practiced a subsistence system based on foraging. Wild plant food resources dominated their vegetal diet. Starch granules extracted from residue samples represent various taxa, including plant roots and tubers, aquatic plant fruits, beans, and wild cereals, defining the primary vegetal diet of Dingsishan’s Neolithic occupants. In addition, residue samples from shell artifacts yielded starch granules and phytolith remains, providing significant clues as to the function of these tools. We also identified millet starch granules from Dingsishan Cultural Phases 3-4 (ca. 7,000–6000 BP), albeit in extremely low quantities. Holocene paleoecological conditions in the Lingnan area provided diverse and plentiful wild food resources, allowing the relatively late emergence of agriculture. Our study suggests that Middle Neolithic human groups in the Yong River drainage consumed various plants, and their subsistence pattern was relatively stable through the four Cultural Phases identified at Dingsishan. Our conclusions enhance understanding the diversity of plant food resources exploited by foraging societies and interpretations of differences in patterns of agricultural origins in different ecological regions of China.

Breeding a series of new rice restorer lines with blast resistance and low‐to‐intermediate apparent amylose contents by integrating marker‐assisted and phenotypic selection

AbstractHybrid rice, as one of the most successful crops exploiting heterosis, has greatly contributed to global food security. Due to its high‐yield potential, approximately half of the rice‐growing area in China is planted with hybrid rice varieties. However, the extreme vulnerability of hybrid rice to various diseases and poor grain quality pose great challenges to rice breeders. Here, we report the development of five new restorer lines pyramiding the broad‐spectrum blast resistance gene Pigm and low/intermediate amylose content‐associated gene Wxb by marker‐assisted and phenotypic selection. All these new restorer lines showed enhanced blast resistance in the disease nursery compared with the original restorer lines and had low‐to‐intermediate apparent amylose contents, ranging from 11.3% to 14.2%. Genetic background analysis based on next‐generation sequencing indicated that the proportion of Gumei 4 (donor of Pigm) genome in the five new restorer lines ranged from 9.89% to 21.69%. Eight of their derived hybrid combinations, which exhibited better grain quality and higher levels of blast resistance, have been certificated for commercial release in different ecological regions of China. Among them, Jing‐Liang‐You 3189, Yue‐Liang‐You 3189, Jing‐Liang‐You 1074 and Long‐Liang‐You 3188 meet the national standards for superior‐quality rice in China. These results confirmed the success of developing elite restorer lines through marker‐assisted and phenotypic selection, and these new restorer lines have great potential in developing more elite hybrid rice combinations.

Evaluation on reprogramed biological processes in transgenic maize varieties using transcriptomics and metabolomics

Genetic engineering (GM) has great potential to improve maize productivity, but rises some concerns on unintended effects, and equivalent as their comparators. There are some limitations through targeted analysis to detect the UE in genetically modified organisms in many previous studies. We here reported a case-study on the effects of introducing herbicides and insect resistance (HIR) gene cassette on molecular profiling (transcripts and metabolites) in a popular maize variety Zhengdan958 (ZD958) in China. We found that introducing HIR gene cassette bring a limited numbers of differential abundant genes (DAGs) or differential abundant metabolites (DAMs) between transgenic events and non-transgenic control. In contrast, averaged 10 times more DAGs and DAMs were observed when performed comparison under different growing environments in three different ecological regions of China than the numbers induced by gene effects. Major biological pathways relating to stress response or signaling transduction could explain somehow the effects of growing environments. We further compared two transgenic events mediated ZD958 (GM-ZD958) with either transgenic parent GM-Z58, and other genetic background nonGM-Z58, nonGM-ZD958, and Chang7-2. We found that the numbers of DAGs and DAMs between GM-ZD958 and its one parent maize variety, Z58 or GM-Z58 is equivalent, but not Chang7-2. These findings suggest that greater effects due to different genetic background on altered molecular profiling than gene modification itself. This study provides a case evidence indicating marginal effects of gene pleiotropic effects, and environmental effects should be emphasized.

Community structure of fungal pathogens causing spikelet rot disease of naked oat from different ecological regions of China

Spikelet rot disease (SRD) is an emerging disease of the grain surface of naked oat in China that affects both grain yield and quality. The typical symptom is discoloration from the black structures of the causal fungi. Here, we investigated the fungal communities on the grain surfaces of cultivar Bayou 13 grown in ten ecological oat-producing regions of China, to identify the main pathogens of naked oat SRD. Our results showed that the growth of Alternaria spp. and Davidiella spp. exhibited a competitive relationship and was mainly affected by the elevations of all 10 ecological regions. The dominant pathogens were Davidiella spp. in Shannan Prefecture in Tibet and Haidong Prefecture in Qinghai Province and Alternaria spp. in the other eight regions. The ratios of black pathogens of interest to all pathogens in Shannan Prefecture and Haidong Prefecture were significantly lower than those of the other eight regions, thus indicating that SRD mainly occurred in regions below 2000 m (elevation). We isolated black fungal pathogens from grain surfaces and deduced that they were Alternaria spp. by sequence comparison. The blackened appearance of the grain surfaces was more evident under spray inoculation with a spore suspension of Alternaria than under the control in greenhouse experiments. The recovered pathogen was the same as the pathogen used for inoculation. We thus concluded that Alternaria alone causes naked oat SRD and mainly infects naked oat in regions below 2000 m, which provides a basis for the recognition and management of SRD of naked oat.

Genetic analysis of yield and fiber quality traits in upland cotton (Gossypium hirsutum L.) cultivated in different ecological regions of China

BackgroundCotton is an important fiber crop worldwide. The yield potential of current genotypes of cotton can be exploited through hybridization. However, to develop superior hybrids with high yield and fiber quality traits, information of genetic control of traits is prerequisite. Therefore, genetic analysis plays pivotal role in plant breeding.ResultsIn present study, North Carolina II mating design was used to cross 5 female parents with 6 male parents to produce 30 intraspecific F1 cotton hybrids. All plant materials were tested in three different ecological regions of China during the year of 2016–2017. Additive-dominance-environment (ADE) genetic model was used to estimate the genetic effects and genotypic and phenotypic correlation of yield and fiber quality traits. Results showed that yield traits except lint percentage were mainly controlled by genetic and environment interaction effects, whereas lint percentage and fiber quality traits were determined by main genetic effects. Moreover, dominant and additive-environment interaction effects had more influence on yield traits, whereas additive and dominance-environment interaction effects were found to be predominant for fiber traits. Broad-sense and its interaction heritability were significant for all yield and most of fiber quality traits. Narrow-sense and its interaction heritability were non-significant for boll number and seed cotton yield. Correlation analysis indicated that seed cotton yield had significant positive correlation with other yield attributes and non-significant with fiber quality traits. All fiber quality traits had significant positive correlation with each other except micronaire.ConclusionsResults of current study provide important information about genetic control of yield and fiber quality traits. Further, this study identified that parental lines, e.g., SJ48–1, ZB-1, 851–2, and DT-8 can be utilized to improve yield and fiber quality traits in cotton.

Combined use of satellite and surface observations to study aerosol optical depth in different regions of China

Aerosol optical depth (AOD) is one of essential atmosphere parameters for climate change assessment as well as for total ecological situation study. This study presents long-term data (2000–2017) on time-space distribution and trends in AOD over various ecological regions of China, received from Moderate Resolution Imaging Spectroradiometer (MODIS) (combined Dark Target and Deep Blue) and Multi-angle Imaging Spectroradiometer (MISR), based on satellite Terra. Ground-based stations Aerosol Robotic Network (AERONET) were used to validate the data obtained. AOD data, obtained from two spectroradiometers, demonstrate the significant positive correlation relationships (r = 0.747), indicating that 55% of all data illustrate relationship among the parameters under study. Comparison of results, obtained with MODIS/MISR Terra and AERONET, demonstrate high relation (r = 0.869 - 0.905), while over 60% of the entire sampling fall within the range of the expected tolerance, established by MODIS and MISR over earth (±0.05 ± 0.15 × AODAERONET and 0.05 ± 0.2 × AODAERONET) with root-mean-square error (RMSE) of 0.097–0.302 and 0.067–0.149, as well as low mean absolute error (MAE) of 0.068–0.18 and 0.067–0.149, respectively. The MODIS search results were overestimated for AERONET stations with an average overestimation ranging from 14 to 17%, while there was an underestimate of the search results using MISR from 8 to 22%.

Genetic Diversity and Relationships of 24 Strains of Genus Auricularia (Agaricomycetes) Assessed Using SRAP Markers.

Auricularia species are well known for their traditional edible and medicinal importance. In this study, sequence-related amplified polymorphism (SRAP) markers were used to evaluate the genetic diversity and relationships of 24 Auricularia strains obtained from different ecological regions of China. A total of 402 polymorphic loci were detected using 11 SRAP primer combinations with 100% polymorphic loci. The similarity coefficient ranged from 0.662 to 0.903, with an average of 0.73. Cluster analysis using the pair-group method using arithmetic average, based on the data from SRAP loci amplified by 11 primer pairs, showed that 24 Auricularia strains were distinguished into 4 groups with 73% similarity. The results of principal coordinate analysis were in accordance with pair-group method using arithmetic average clustering, and the first, most informative coordinate accounted for 74.38% of all the variations, which indicated a high level of genetic diversity among Auricularia strains. In general, SRAP markers provide a powerful tool to discriminate Auricularia strains and to evaluate their genetic relationships.

Effect of Environment on Yield and Quality of Rice Recombinant Inbred Lines

Global climate change affects not only rice yield but also grain quality. A better understanding of the effect of environment factors on rice yield and quality provides information for breeding new varieties adapted to a changing world. This study uses indica-japonica recombinant inbred lines (RILs) constructed in different ecological regions of China as test materials. The objectives were to determine the effect of environment on rice yield and quality. The results revealed that: the yield of RILs in Liaoning was greater than that in the other regions, milling and appearance qualities in Sichuan and Guangdong were worse than that in Liaoning and Shanghai. High temperature and high relative humidity combined with low sunshine duration were the main reason for lower milling quality and greater chalkiness traits. The air temperature during heading stage and maturity stage seemed more important for rice milling and appearance qualities throughout the growing season.

Establishment and Application of TRV-Mediated Virus-Induced Gene Silencing in Cotton

Using upland cotton GhCLA1 as marker gene, tobacco rattle virus induced genes silencing(TRV-VIGS) was established in cotton. A gene fragment of TRV subgenomic RNA2 was amplified by reverse transcription-polymerase chain reaction(RT-PCR) in root, stem and leaf of cotton, demonstrating the virus can spread into various organs. The TRV induced silencing of CLA1 gene was further tested in 34 different cotton varieties(lines) originated from several ecological regions of China. The results showed that CLA1 could be silenced in all tested varieties(lines), though the levels of silencing showed a little difference, implicating wide application perspective of TRV-VIGS system in cotton. GhMAPKKK, a mitogen-activated protein kinase(MAPK) kinase kinase gene of cotton, was up-regulated in cotton at 96 hours post inoculation by Verticillium dahliae. Silencing GhMAPKKK in G. barbadense cv. Hai 7124, a cotton variety with high resistance to V. dahlia exhibited reduced resistance to V. dahliae infection, suggesting that GhMAPKKK participated in cotton resistance signaling pathway to V. dahliae. With the wide adaption without genotype selection, sensitivity and high throughput, the TVR-VIGS system will significantly promote functional gene analysis in cotton.

Genetic diversity of wild Auricularia auricula-judae revealed by ISSR analysis

Abstract Auricularia auricula-judae is an edible and medicinal jelly mushroom, and it is widely cultivated in China. In the present study, inter-simple sequence repeat (ISSR) molecular marker was employed to assess the genetic diversity of 22 wild strains and two cultivars of A. auricula-judae obtained from many ecological regions of China. With the use of 11 ISSR primers, a total of 368 (99.7%) and 81 (71.7%) polymorphic loci in wild and cultivated strains were detected, respectively. The mean genetic similarity of A. auricula-judae was 0.75, based on the dendrogram generated via similarity coefficient, all the tested strains were classified into six groups at a similarity level of 76%, and the two cultivated strains consisted of one group alone. The results of principal coordinate analysis were in accordance with UPGMA clustering, and the first most informative coordinate accounted for 75.9% of the variations, indicated a high level of genetic diversity among wild A. auricula-judae strains. In general, ISSR marker was an effective method to discriminate the A. auricula-judae stains and to evaluate their genetic diversity.

Genetic diversity and biogeography of rhizobia associated with Caragana species in three ecological regions of China

Twenty-two genospecies belonging mainly to Mesorhizobium, and occasionally to Rhizobium and Bradyrhizobium, were defined among the 174 rhizobia strains isolated from Caragana species. Highly similar nodC genes were found in the sole Bradyrhizobium strain and among all the detected Mesorhizobium strains. A clear correlation between rhizobial genospecies and the eco-regions where they were isolated was found using homogeneity analysis. All these results demonstrated that Caragana species had stringently selected the rhizobia symbiotic genotype, but not the genomic background; lateral transfer of symbiotic genes from Mesorhizobium to Bradyrhizobium and among the Mesorhizobium species has happened in the Caragana rhizobia; and biogeography of Caragana rhizobia exists. Furthermore, a combined cluster analysis, based upon the patterns obtained from amplified 16S rRNA gene and 16S–23S intergenic spacer restriction analyses, BOX PCR and SDS-PAGE of proteins, was reported to be an efficient method to define the genospecies.

Genetic diversity of rhizobia associated with Vicia faba in three ecological regions of China

Great genetic diversity was revealed among 75 rhizobal isolates associated with Vicia faba grown in Chinese fields with AFLP, ARDRA, 16S rDNA sequencing, DNA-DNA hybridization, BOX-PCR and RFLP of PCR-amplified nodD and nodC. Most of the isolates were Rhizobium leguminosarum, and six isolates belonged to an unnamed Rhizobium species. In the homogeneity analysis, the isolates were grouped into three clusters corresponding to (1) autumn sowing (subtropical) region where the winter ecotype of V. faba was cultivated, (2) spring sowing (temperate) region where the spring ecotype was grown, and (3) Yunnan province where the intermediate ecotype was sown either in spring or in autumn. Nonrandom associations were found among the nod genotypes, genomic types and ecological regions, indicating an epidemic symbiotic gene transfer pattern among different genomic backgrounds within an ecological region and a relatively limited transfer pattern between different regions. Conclusively, the present results suggested an endemic population structure of V. faba rhizobia in Chinese fields and demonstrated a novel rhizobium associated with faba bean.

Characterization of nitrifying bacteria communities of soils from different ecological regions of China by molecular and conventional methods

Soil nitrification rate is very different among soil types, as a result of differences in physical and chemical properties. Little is known about the composition of the nitrifying bacteria community. In this investigation, three soils (fluvo-aquic soil, permeable paddy soil and red earth) from different geo-ecological regions in China were characterized for their nitrification activities and their nitrifying bacteria communities determined either by molecular approaches or by conventional culture methods. A 28-day long-term soil incubation showed that the maximum nitrification potential was found in the fluvo-aquic soil with almost 100% of inorganic N present as NO 3 − -N, while the minimum nitrification potential was in red earth with only a 4.9% conversion rate from ammonium into nitrate. There was no relationship between nitrification potential and numbers of nitrifiers in the soil. The conventional most probable number (MPN) method could enumerate ammonia oxidizers, but failed in enumerating nitrite oxidizers. Therefore, we used an MPN-PCR procedure which gave a convincing nitrite oxidizer count result, instead of MPN-diphylamine. Soils were characterized by denaturing gradient gel electrophoresis (DGGE) of DNA extracted from soils and amplified using a primer specific for the 16S rRNA gene and/or for the amoA gene. The DGGE columns of the three soils differed from each other. There were two similar bands present in DGGE columns of the fluvo-aquic and permeable paddy soils, but no similar band was found in DGGE columns of the red earth. The sequence of amoA indicated that all ammonia oxidizers in these soils were grouped into Nitrosospira clusters 1 and 3, and each soil had a common band similar to the other soils and a special band which differed from the other soils.