To ascertain the genetic diversity of gray leaf spot pathogen on Dictamnus dasycarpus popoulation in Heilongjiang Province,a total of 57 strains of Paracercospora dictamnicola were isolated and purified from the disea...To ascertain the genetic diversity of gray leaf spot pathogen on Dictamnus dasycarpus popoulation in Heilongjiang Province,a total of 57 strains of Paracercospora dictamnicola were isolated and purified from the diseased samples collected from five Chinese herbal medicine planting areas in Heilongjiang Province between the years of 2021 and 2022.Repetitive extragenic palindromic polymerase chain reaction(Rep–PCR)was used to amplify 57 isolates of gray leaf spot pathogen on D.dasycarpus from different regions of Heilongjiang Province.The polymorphic bands amplified by three sets of primers accounted for more than 80%.Cluster analysis results showed that at a similarity coefficient of 0.67,the gray leaf spot pathogen on D.dasycarpus in Heilongjiang Province could be divided into five major genetic groups.Genetic diversity parameter analysis indicated that there were certain differences in genetic richness among the geographic populations of gray leaf spot pathogen on D.dasycarpus from different regions.Analysis of molecular variance(AMOVA)revealed that genetic variation among strains mainly originated within populations.The genetic differentiation and relationships of gray leaf spot pathogen on D.dasycarpus from different geographic regions of Heilongjiang Province indicated that genetic differentiation and kinship among populations were somewhat related to their geographic distance.The greater the geographic distance,the higher the genetic differentiation coefficient,and the lower the genetic uniformity among populations.展开更多
[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in t...[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.展开更多
When performing tasks,unmanned clusters often face a variety of strategy choices.One of the key issues in unmanned cluster tasks is the method through which to design autonomous collaboration and cooperative evolution...When performing tasks,unmanned clusters often face a variety of strategy choices.One of the key issues in unmanned cluster tasks is the method through which to design autonomous collaboration and cooperative evolution mechanisms that allow for unmanned clusters to maximize their overall task effective-ness under the condition of strategic diversity.This paper ana-lyzes these task requirements from three perspectives:the diver-sity of the decision space,information network construction,and the autonomous collaboration mechanism.Then,this paper pro-poses a method for solving the problem of strategy selection diversity under two network structures.Next,this paper presents a Moran-rule-based evolution dynamics model for unmanned cluster strategies and a vision-driven-mechanism-based evolu-tion dynamics model for unmanned cluster strategy in the con-text of strategy selection diversity according to various unmanned cluster application scenarios.Finally,this paper pro-vides a simulation analysis of the effects of relevant parameters such as the payoff factor and cluster size on cooperative evolu-tion in autonomous cluster collaboration for the two types of models.On this basis,this paper presents advice for effectively addressing diverse choices in unmanned cluster tasks,thereby providing decision support for practical applications of unmanned cluster tasks.展开更多
The family Osmundaceae receives much concern of palaeobotanists for its peculiar sporangia and phylogenetic relationship.Abundant osmundaceous fossils have been reported in China.So far,about 34 species ascribed to se...The family Osmundaceae receives much concern of palaeobotanists for its peculiar sporangia and phylogenetic relationship.Abundant osmundaceous fossils have been reported in China.So far,about 34 species ascribed to seven genera of Osmundaceae have been documented except for three morphogenera.展开更多
Chinese mitten crab （Eriocheir sinensis） is an indigenous and ecologically and economically important species in the Liao River area, but its identification and genetic diversity remain poorly understood. To evaluat...Chinese mitten crab （Eriocheir sinensis） is an indigenous and ecologically and economically important species in the Liao River area, but its identification and genetic diversity remain poorly understood. To evaluate the germplasm resources of this species, samples were collected from these locations： four sub-populations from the Liao River area and one population from the Yangtze River area; one primer was used to distinguish between the Liao River and the Yangtze River crabs. Thirteen loci were used for crab genetic diversity analysis, and basic statistics showed that the collecting samples were purebred in the Liao River area. The average observed heterozygosity （H0） of the Liao River population was 0.5931, and the expected heterozygosity （He） was 0.8064. The polymorphism information content （PIC） was 0.7753, which showed that the Liao River population had high genetic diversity. The genetic differentiation index （FST） averaged 0.0342, meaning a low degree of differentiation; cluster analysis indicated that Hujia （HJ）, Xinli （XL） and Chenjia （CJ） sub-populations were allocated to the same cluster, while Baqiangzi （BQZ） sub-population was isolated. In summary, these data demonstrated that the crabs in the Liao River had high genetic diversity, but low genetic differentiation. Thus, the Liao River population had the potential for breeding selection. Furthermore, this study also provided valuable genetic information for the conservation of Chinese mitten crab.展开更多
The ISSR method was developed to analyze the genetic diversity of 20 wild Wusuli raccoon dog from Nenjiang district. The results showed that there were significant genetic diversity and high polymorphism among individ...The ISSR method was developed to analyze the genetic diversity of 20 wild Wusuli raccoon dog from Nenjiang district. The results showed that there were significant genetic diversity and high polymorphism among individuals of the wild Wusuli raccoon dog. A total of 41 DNA bands were amplified by 9 primers, and 37 of them were polymorphism, the proportion of polymorphism was 90.24%, 2-8 polymorphism bands could be amplified by each primer, and 4.56 on average, the length of the product was 200-2 000 bp.展开更多
With its wide use in different fields, the problem of the convergence of simple genetic algorithms (GAs) has been concerned. In the past, the research on the convergence of GAs was based on Holland's model theorem...With its wide use in different fields, the problem of the convergence of simple genetic algorithms (GAs) has been concerned. In the past, the research on the convergence of GAs was based on Holland's model theorem. The diversity of the evolutionary population and the convergence of GAs are studied by using the concept of negentropy based on the discussion of the characteristic of GA. Some test functions are used to test the convergence of GAs, and good results have been obtained. It is shown that the global optimization may be obtained by selecting appropriate parameters of simple GAs if the evolution time is enough.展开更多
Inter-simple Sequence Repeat （ISSR） analysis was applied to assess the genetic diversity within and among five populations of mink from Liaoning Province. A total of 20 primers were screened, five selected primers p...Inter-simple Sequence Repeat （ISSR） analysis was applied to assess the genetic diversity within and among five populations of mink from Liaoning Province. A total of 20 primers were screened, five selected primers produced 35 discernible bands, with 30 （85.71%） being polymorphic, indicating high genetic diversity at the species level. The highest genetic diversity was observed in the brown mink population, whereas the lowest diversity was found in the standard-pitchy mink population. Based on genetic distance （1972）, a dendrogram was constructed by using UPGMA algorithm, and five populations were divided into two major groups. Group I consisted of only the standard-pitchy mink population, and Group II included other four populations, in Group II, sapphire mink was close to brown mink population. The results of genetic differentiation indicated that the genetic differentiation degree between populations was lower and the genetic variation primarily came from within populations. This paper showed that ISSR technique was a reliable tool that could be used to study genetic diversity in the mink.展开更多
Microorganisms,one of the key factors affecting the bioleaching process,change the components of extracellular polymeric substance(EPS)and community structure to survive in leaching environments.In this work,Fourier t...Microorganisms,one of the key factors affecting the bioleaching process,change the components of extracellular polymeric substance(EPS)and community structure to survive in leaching environments.In this work,Fourier transform infrared(FTIR),X-ray powder diffraction(XRD)and 16S rDNA high-throughput sequence analyses were used to reveal the microbial changes in planktonic and sessile phases during bioleaching.The results showed the occupation of sessile cells decreased from 66.2%to(10±3)%.After bioleaching,the planktonic and sessile cells have similar EPS,but they are different from the original cells.Pyrite dissolution mainly occurs at the early and late stages with the decreasing of particle diameter,by 50%and 40%,respectively.The 16S rDNA gene based sequence analysis results in total of 1117420 Reads across the six samples,presented among 7 phyla,9 classes,17 orders,23 families and 31 genera.Genera Leptospirillum and Sulfobacillus are the main bacteria at the early and middle stages,and Leptospirillum is the main genus at the end of bioleaching.Aquabacterium and Acidovorax are special genera in sessile cells and Weissella is special in planktonic ones.展开更多
Unionidae are an important group of benthic freshwater species.Due to the convergence phenomenon within freshwater mussels,there is still much controversy in the classification of Chinese Unionidae.In China,most studi...Unionidae are an important group of benthic freshwater species.Due to the convergence phenomenon within freshwater mussels,there is still much controversy in the classification of Chinese Unionidae.In China,most studies on freshwater mussels emphasized resource investigation,biology and morphology,while little has been done in genetics,and particularly not in population genetic structure as well as genetic diversity.In order to further understand the status of genetic diversity of different species,random amplified polymorphic DNA(RAPD)markers were used to detect genetic diversity of populations in five species of the genus Anodonta:Anodonta arcaeformis,A.arcaeformis flavotincta,A.fluminea,A.woodiana woodiana and A.w.pacifica.DNA extraction method was based on phenol-chloroform and extracted genomic DNA from the adductor muscle and mantle tissues.Sixteen random primers were used for RAPD amplification and the polymorphism of amplified loci were analyzed.The results demonstrated that the percentage of amplified polymorphic loci for various populations ranged from 34.5%to 62.8%,the mean Shannon’s genetic diversity indices ranged from 0.2021 to 0.3552,and the mean intra-population Nei’s genetic distance ranged from 0.1386 to 0.1713.In all populations of the five species,the genetic diversity for A.arcaeformis was the largest,and that of A.fluminea was the lowest.The inter-population genetic distance between A.w.woodiana and A.w.pacifica was 0.3186,so they can be considered as two sister species at the genetic angle.展开更多
We used microsatellite markers to investigate the genetic parameters of three different polyploidy populations of Misgurnus anguillicaudatus from Honghu City, Hubei Province. Polyacrylamide gel electrophoresis banding...We used microsatellite markers to investigate the genetic parameters of three different polyploidy populations of Misgurnus anguillicaudatus from Honghu City, Hubei Province. Polyacrylamide gel electrophoresis banding patterns of diploid（2n）, triploid（3n） and tetraploid loaches（4n） were analyzed with Pop Gen software. A total of 68 alleles were obtained from seven microsatellite loci and the polymorphism information content（PIC） indices were all above 0.5. The average expected mean heterozygosity values（He） were 0.8420, 0.7186 and 0.8521; the average observed mean heterozygosity values（Ho） were 0.9674, 0.9785 and 0.8928; and the HardyWeinberg P values were 0.3078, 0.3151 and 0.3762, for diploid, triploid and tetraploid individuals, respectively. The results indicated that the three populations were highly polymorphic, with no deviations from Hardy-Weinberg equilibrium observed at all the seven microsatellite loci. This indicated a high level of genetic diversity within the populations. A cluster analysis diagram showed that the shortest genetic distance was between diploid and tetraploid loaches and they shared a close phylogenetic relationship. The triploid and tetraploid individuals had the most distant phylogenetic relationship.展开更多
Many common multimedia signal processing,including cropping,filtering,and perceptual coding,make watermark signal fading-like modification.A scheme that applies transmit diversity technique to improve robustness of di...Many common multimedia signal processing,including cropping,filtering,and perceptual coding,make watermark signal fading-like modification.A scheme that applies transmit diversity technique to improve robustness of digital watermarking is presented.First,the scheme decomposes the original image using wavelet pyramid algorithm and chooses the middle-frequency band for transmission channel that the watermark will be embedded into.Then the watermark is pseudo-randomly permuted.The scheme makes use of space-time coding and differential detection technique to embed and extract watermark.The extracting process has access to neither the original image nor channel state information.Experimental results demonstrate that the scheme improves the performance of robust watermarking.展开更多
To improve the error performance and the resource utilization of cooperative systems, the optimum resource allocation, i.e., power allocation and partner choice, for an adaptive decode-and-forward （DF） cooperative d...To improve the error performance and the resource utilization of cooperative systems, the optimum resource allocation, i.e., power allocation and partner choice, for an adaptive decode-and-forward （DF） cooperative diversity system based on quadrature modulation is investigated. The closed-form expression of the bit error rate （BER） system performance is derived and an optimal power allocation （OPA） algorithm is proposed to optimize the power allocation between the local and relayed signals under the minimum BER criterion. Based on the OPA algorithm, a partner choice strategy is proposed to determine the partner locations specified by various cooperation gains. Simulation results show that the proposed resource optimization algorithms are superior to the unoptimized algorithms by significantly reducing the BER and improving the cooperative gain, which is useful to simplify the practical partner choice process.展开更多
DNA fingerprints of 37 PVY resistant potato varieties （clones） were generated using PCR-based RAPD analysis. All 37 varieties were differentiated by banding patterns obtained from 17 primers that generated 164 polym...DNA fingerprints of 37 PVY resistant potato varieties （clones） were generated using PCR-based RAPD analysis. All 37 varieties were differentiated by banding patterns obtained from 17 primers that generated 164 polymorphisms. Similarity matrices were calculated with the simple matching coefficient. The genetic distance value among them was between 0.27 and 0.50, with average value being 0.35. The average link clustering algorithm was used to construct a dendrogram with Statistica. They were classified into three groups according to clustering results, and the results presented some geographic relationship. Dendrogram showed close genetic relationships between a number of varieties （clones） of similar pedigree. This study has shown that RAPD marker is a useful tool for potato variety identification, differentiation, and estimation of genetic relationships.展开更多
A total of 69 random primers were screened by using random amplified polymorphic DNA （RAPD） markers to analyze the genetic bands of 32 Kentucky bluegrass cultivars. A total of 197 bands were amplified from 46 primer...A total of 69 random primers were screened by using random amplified polymorphic DNA （RAPD） markers to analyze the genetic bands of 32 Kentucky bluegrass cultivars. A total of 197 bands were amplified from 46 primers, among which 195 bands were polymorphic. Each primer could amplify one to nine polymorphic bands with an average of 4.3 per primer. Based on similarity coefficient analysis of RAPD results and by using NTSYS software to cluster analyze with the average UPGMA method, the result showed that 18 cultivars of the 32 were in group 1, three cultivars were in group 2, two cultivars were in group 3, eight cultivars were in group 4, and only one cultivar in group 5.展开更多
Background Plant pollen has diverse morphological characteristics that can be consistently passed down from generation to generation.Information on pollen morphology is thus immensely important for plant classificatio...Background Plant pollen has diverse morphological characteristics that can be consistently passed down from generation to generation.Information on pollen morphology is thus immensely important for plant classification and identification.In the genus Gossypium,however,in-depth research on pollen morphology is lacking,with only few reports on limited cotton species.To evaluate the diversity of pollen in Gossypium,we therefore conducted a comprehensive analysis of the pollen morphology of 33 cotton species and varieties using scanning electron microscopy.Results The 33 analyzed cotton samples exhibited common pollen morphological features,including spherical shapes,radial symmetry,echination,panporation,and operculation,while the pollen size,spine shape,spine density and length showed distinctive features.Pollen size varied significantly among species,with diameters ranging from62.43 μm in G.harknessii to 103.41 μm in G.barbadense.The exine had an echinate sculptural texture,and spines were mostly conical or sharply conical but occasionally rod-like.Spine density varied from 173 in G.incanum to 54 in G.gossypioides,while spine length ranged from 3.53 μm in G.herbaceum to 9.47 μm in G.barbadense.In addition,the 33cotton species and varieties were grouped at a genetic distance of 3.83 into three clusters.Cluster Ⅰ comprised five allotetraploid AD-genome cotton species,four D-genome species,and one K-genome species.Cluster Ⅱ included 13diploid species from A,B,D,E,and G genomes,whereas Cluster Ⅲ only consisted one E-genome species G.incanum.Conclusions Although pollen characteristics alone are not enough to resolve taxonomic and systematic relationships within the genus Gossypium,our results add to knowledge on palynomorphology and contribute to phenological information on these taxa.Our findings should aid future systematic and phylogenetic studies of the Gossypium genus.展开更多
Background: Gossypium arboreum is a diploid species cultivated in the Old World. It possesses favorable characters that are valuable for developing superior cotton cultivars.Method: A set of 197 Gossypium arboreum acc...Background: Gossypium arboreum is a diploid species cultivated in the Old World. It possesses favorable characters that are valuable for developing superior cotton cultivars.Method: A set of 197 Gossypium arboreum accessions were genotyped using 80 genome-wide SSR markers to establish patterns of the genetic diversity and population structure. These accessions were collected from three major G. arboreum growing areas in China. A total of 255 alleles across 80 markers were identified in the genetic diversity analysis.Results: Three subgroups were found using the population structure analysis, corresponding to the Yangtze River Valley, North China, and Southwest China zones of G.arboreum growing areas in China. Average genetic distance and Polymorphic information content value of G. arboreum population were 0.34 and 0.47, respectively, indicating high genetic diversity in the G. arboreum germplasm pool. The Phylogenetic analysis results concurred with the subgroups identified by Structure analysis with a few exceptions. Variations among and within three groups were observed to be 13.61% and 86.39%, respectively.Conclusion: The information regarding genetic diversity and population structure from this study is useful for genetic and genomic analysis and systematic utilization of economically important traits in G. arboreum.展开更多
A novel practical codebook-precoding multiple-input multiple-output（MIMO） system based on signal space diversity（SSD） with the minimum mean squared error（MMSE）receiver is proposed.This scheme utilizes rotation m...A novel practical codebook-precoding multiple-input multiple-output（MIMO） system based on signal space diversity（SSD） with the minimum mean squared error（MMSE）receiver is proposed.This scheme utilizes rotation modulation and space-time-frequency component interleaving.A novel precoding matrix selection criterion to maximize the average signal to interference plus noise ratio（SINR） is also put forward for the proposed scheme,which has a larger average mutual information（AMI）.Based on the AMI- maximization criterion,the optimal rotation angles for the proposed system are also investigated.The new scheme can make full use of space-time-frequency diversity and signal space diversity,and exhibit high spectral efficiency and high reliability in fading channels.Simulation results show that the proposed scheme greatly outperforms the conventional bit- interleaved coded modulation（BICM） MIMO-orthogonal frequency division multiplexing（OFDM） scheme without SSD,which is up to4.5 dB signal-to-noise ratio（SNR） gain.展开更多
The phylogeny and diversity of two key functional genes were investigated as the basis for improved understanding of the community structure of natural phytoplankton assemblages in marine environments. New partial NR(...The phylogeny and diversity of two key functional genes were investigated as the basis for improved understanding of the community structure of natural phytoplankton assemblages in marine environments. New partial NR(encoding eukaryotic assimilatory nitrate reductase) and rbcL(encoding the large subunit of the ribulose-1,5-bisphosphate carboxylase/oxygenase) sequences from ten cultured phytoplankton strains are reported.Phytoplankton community com-展开更多
Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the e...Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the early breeding period;1971-1990,the mid-breeding period;and 1991-2010,the current breeding period)in northeast China were selected.Fourteen DNA-specified markers including cleaved amplified polymorphic sequences(CAPS),derived CAPS(d CAPS)and fragment length polymorphism(FLP)markers were filtered to analyze the genetic diversity from E1 to E4.The results were as the followings:the soybean varieties with more gene frequencies showed more gene diversities.Among the E genes,E1 and E3 genes showed more allelic diversities than E2,and E4 only had diversity in the early breeding period.During the artificial process,some alleles of E genes disappeared and some new ones were generated.More gene diversities were observed in soybean germplasms,and new excellent germplasms could be explored to improve yield traits in artificial breeding programs.Furthermore,six different E gene combinations were observed in the early breeding period,five in the mid-breeding period and 11 in the current breeding period.Three elite genotypes were identified through a century artificial selection,while new genotypes were also found in different breeding periods.Of them,e1-nle2e3-tr E4 was a new soybean genotype of extremely early maturity in the current breeding period,which was widely suitable for planting in 00 and 000 maturity groups.Moreover,significant correlation was found between E2 and E3,suggesting that light length and light quality were two key factors for soybean maturity in northeast China.The understanding of the E genes variation underlying soybean maturity could facilitate the procession to breed elite varieties adapted for diverse regions.展开更多
基金Supported by the Green Plant Protection Project of Heilongjiang Province(2130108)Key R&D Program Project of Heilongjiang Province(2023ZX02B0502)Heilongjiang Province Rice Modern Agriculture Industry Technology Collaborative Innovation System Project(2025)。
文摘To ascertain the genetic diversity of gray leaf spot pathogen on Dictamnus dasycarpus popoulation in Heilongjiang Province,a total of 57 strains of Paracercospora dictamnicola were isolated and purified from the diseased samples collected from five Chinese herbal medicine planting areas in Heilongjiang Province between the years of 2021 and 2022.Repetitive extragenic palindromic polymerase chain reaction(Rep–PCR)was used to amplify 57 isolates of gray leaf spot pathogen on D.dasycarpus from different regions of Heilongjiang Province.The polymorphic bands amplified by three sets of primers accounted for more than 80%.Cluster analysis results showed that at a similarity coefficient of 0.67,the gray leaf spot pathogen on D.dasycarpus in Heilongjiang Province could be divided into five major genetic groups.Genetic diversity parameter analysis indicated that there were certain differences in genetic richness among the geographic populations of gray leaf spot pathogen on D.dasycarpus from different regions.Analysis of molecular variance(AMOVA)revealed that genetic variation among strains mainly originated within populations.The genetic differentiation and relationships of gray leaf spot pathogen on D.dasycarpus from different geographic regions of Heilongjiang Province indicated that genetic differentiation and kinship among populations were somewhat related to their geographic distance.The greater the geographic distance,the higher the genetic differentiation coefficient,and the lower the genetic uniformity among populations.
文摘[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.
基金supported by the National Natural Science Foundation of China(72471240).
文摘When performing tasks,unmanned clusters often face a variety of strategy choices.One of the key issues in unmanned cluster tasks is the method through which to design autonomous collaboration and cooperative evolution mechanisms that allow for unmanned clusters to maximize their overall task effective-ness under the condition of strategic diversity.This paper ana-lyzes these task requirements from three perspectives:the diver-sity of the decision space,information network construction,and the autonomous collaboration mechanism.Then,this paper pro-poses a method for solving the problem of strategy selection diversity under two network structures.Next,this paper presents a Moran-rule-based evolution dynamics model for unmanned cluster strategies and a vision-driven-mechanism-based evolu-tion dynamics model for unmanned cluster strategy in the con-text of strategy selection diversity according to various unmanned cluster application scenarios.Finally,this paper pro-vides a simulation analysis of the effects of relevant parameters such as the payoff factor and cluster size on cooperative evolu-tion in autonomous cluster collaboration for the two types of models.On this basis,this paper presents advice for effectively addressing diverse choices in unmanned cluster tasks,thereby providing decision support for practical applications of unmanned cluster tasks.
文摘The family Osmundaceae receives much concern of palaeobotanists for its peculiar sporangia and phylogenetic relationship.Abundant osmundaceous fossils have been reported in China.So far,about 34 species ascribed to seven genera of Osmundaceae have been documented except for three morphogenera.
基金Supported by Open Project Program of Key Laboratory of Freshwater Aquatic Biotechnology and Breeding,Ministry of Agriculture,Heilongjiang Fisheries Research Institute,Chinese Academy of Fishery Sciences(FBB2016-01)
文摘Chinese mitten crab （Eriocheir sinensis） is an indigenous and ecologically and economically important species in the Liao River area, but its identification and genetic diversity remain poorly understood. To evaluate the germplasm resources of this species, samples were collected from these locations： four sub-populations from the Liao River area and one population from the Yangtze River area; one primer was used to distinguish between the Liao River and the Yangtze River crabs. Thirteen loci were used for crab genetic diversity analysis, and basic statistics showed that the collecting samples were purebred in the Liao River area. The average observed heterozygosity （H0） of the Liao River population was 0.5931, and the expected heterozygosity （He） was 0.8064. The polymorphism information content （PIC） was 0.7753, which showed that the Liao River population had high genetic diversity. The genetic differentiation index （FST） averaged 0.0342, meaning a low degree of differentiation; cluster analysis indicated that Hujia （HJ）, Xinli （XL） and Chenjia （CJ） sub-populations were allocated to the same cluster, while Baqiangzi （BQZ） sub-population was isolated. In summary, these data demonstrated that the crabs in the Liao River had high genetic diversity, but low genetic differentiation. Thus, the Liao River population had the potential for breeding selection. Furthermore, this study also provided valuable genetic information for the conservation of Chinese mitten crab.
文摘The ISSR method was developed to analyze the genetic diversity of 20 wild Wusuli raccoon dog from Nenjiang district. The results showed that there were significant genetic diversity and high polymorphism among individuals of the wild Wusuli raccoon dog. A total of 41 DNA bands were amplified by 9 primers, and 37 of them were polymorphism, the proportion of polymorphism was 90.24%, 2-8 polymorphism bands could be amplified by each primer, and 4.56 on average, the length of the product was 200-2 000 bp.
文摘With its wide use in different fields, the problem of the convergence of simple genetic algorithms (GAs) has been concerned. In the past, the research on the convergence of GAs was based on Holland's model theorem. The diversity of the evolutionary population and the convergence of GAs are studied by using the concept of negentropy based on the discussion of the characteristic of GA. Some test functions are used to test the convergence of GAs, and good results have been obtained. It is shown that the global optimization may be obtained by selecting appropriate parameters of simple GAs if the evolution time is enough.
文摘Inter-simple Sequence Repeat （ISSR） analysis was applied to assess the genetic diversity within and among five populations of mink from Liaoning Province. A total of 20 primers were screened, five selected primers produced 35 discernible bands, with 30 （85.71%） being polymorphic, indicating high genetic diversity at the species level. The highest genetic diversity was observed in the brown mink population, whereas the lowest diversity was found in the standard-pitchy mink population. Based on genetic distance （1972）, a dendrogram was constructed by using UPGMA algorithm, and five populations were divided into two major groups. Group I consisted of only the standard-pitchy mink population, and Group II included other four populations, in Group II, sapphire mink was close to brown mink population. The results of genetic differentiation indicated that the genetic differentiation degree between populations was lower and the genetic variation primarily came from within populations. This paper showed that ISSR technique was a reliable tool that could be used to study genetic diversity in the mink.
基金Project(U1608254)supported by the Special Fund for the National Natural Science Foundation of ChinaProjects(ZJKY2017(B)KFJJ01,ZJKY2017(B)KFJJ02)supported by the Zijin Mining Group Co.,Ltd.,China。
文摘Microorganisms,one of the key factors affecting the bioleaching process,change the components of extracellular polymeric substance(EPS)and community structure to survive in leaching environments.In this work,Fourier transform infrared(FTIR),X-ray powder diffraction(XRD)and 16S rDNA high-throughput sequence analyses were used to reveal the microbial changes in planktonic and sessile phases during bioleaching.The results showed the occupation of sessile cells decreased from 66.2%to(10±3)%.After bioleaching,the planktonic and sessile cells have similar EPS,but they are different from the original cells.Pyrite dissolution mainly occurs at the early and late stages with the decreasing of particle diameter,by 50%and 40%,respectively.The 16S rDNA gene based sequence analysis results in total of 1117420 Reads across the six samples,presented among 7 phyla,9 classes,17 orders,23 families and 31 genera.Genera Leptospirillum and Sulfobacillus are the main bacteria at the early and middle stages,and Leptospirillum is the main genus at the end of bioleaching.Aquabacterium and Acidovorax are special genera in sessile cells and Weissella is special in planktonic ones.
基金the Special Project Foundation(Grant No.2000050406)of Doctoral DegreeMinistry of Education,andthe Natural Science Foundation(Grant No.99J104)of Hubei Province,P.R.China
文摘Unionidae are an important group of benthic freshwater species.Due to the convergence phenomenon within freshwater mussels,there is still much controversy in the classification of Chinese Unionidae.In China,most studies on freshwater mussels emphasized resource investigation,biology and morphology,while little has been done in genetics,and particularly not in population genetic structure as well as genetic diversity.In order to further understand the status of genetic diversity of different species,random amplified polymorphic DNA(RAPD)markers were used to detect genetic diversity of populations in five species of the genus Anodonta:Anodonta arcaeformis,A.arcaeformis flavotincta,A.fluminea,A.woodiana woodiana and A.w.pacifica.DNA extraction method was based on phenol-chloroform and extracted genomic DNA from the adductor muscle and mantle tissues.Sixteen random primers were used for RAPD amplification and the polymorphism of amplified loci were analyzed.The results demonstrated that the percentage of amplified polymorphic loci for various populations ranged from 34.5%to 62.8%,the mean Shannon’s genetic diversity indices ranged from 0.2021 to 0.3552,and the mean intra-population Nei’s genetic distance ranged from 0.1386 to 0.1713.In all populations of the five species,the genetic diversity for A.arcaeformis was the largest,and that of A.fluminea was the lowest.The inter-population genetic distance between A.w.woodiana and A.w.pacifica was 0.3186,so they can be considered as two sister species at the genetic angle.
基金Supported by the Natural Science Foundation of China(31272650)the Natural Science Foundation of Liaoning Province(201102019)
文摘We used microsatellite markers to investigate the genetic parameters of three different polyploidy populations of Misgurnus anguillicaudatus from Honghu City, Hubei Province. Polyacrylamide gel electrophoresis banding patterns of diploid（2n）, triploid（3n） and tetraploid loaches（4n） were analyzed with Pop Gen software. A total of 68 alleles were obtained from seven microsatellite loci and the polymorphism information content（PIC） indices were all above 0.5. The average expected mean heterozygosity values（He） were 0.8420, 0.7186 and 0.8521; the average observed mean heterozygosity values（Ho） were 0.9674, 0.9785 and 0.8928; and the HardyWeinberg P values were 0.3078, 0.3151 and 0.3762, for diploid, triploid and tetraploid individuals, respectively. The results indicated that the three populations were highly polymorphic, with no deviations from Hardy-Weinberg equilibrium observed at all the seven microsatellite loci. This indicated a high level of genetic diversity within the populations. A cluster analysis diagram showed that the shortest genetic distance was between diploid and tetraploid loaches and they shared a close phylogenetic relationship. The triploid and tetraploid individuals had the most distant phylogenetic relationship.
基金supported by the National Natural Science Foundation of China(60072041).
文摘Many common multimedia signal processing,including cropping,filtering,and perceptual coding,make watermark signal fading-like modification.A scheme that applies transmit diversity technique to improve robustness of digital watermarking is presented.First,the scheme decomposes the original image using wavelet pyramid algorithm and chooses the middle-frequency band for transmission channel that the watermark will be embedded into.Then the watermark is pseudo-randomly permuted.The scheme makes use of space-time coding and differential detection technique to embed and extract watermark.The extracting process has access to neither the original image nor channel state information.Experimental results demonstrate that the scheme improves the performance of robust watermarking.
基金supported by the National High Technology Research and Development Program of China (863 program) (2006AA01Z270)the National Major Specialized Project of Science and Technology(2009ZX03003-003+4 种基金 2009ZX03003-004)the Fundamental Research Funds for the Central University (K50510010017)the Program for Changjiang Scholars and Innovative Research Team in University(IRT0852)the "111" Project (B08038)the Open Research Fund of State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University (RCS2008K003)
文摘To improve the error performance and the resource utilization of cooperative systems, the optimum resource allocation, i.e., power allocation and partner choice, for an adaptive decode-and-forward （DF） cooperative diversity system based on quadrature modulation is investigated. The closed-form expression of the bit error rate （BER） system performance is derived and an optimal power allocation （OPA） algorithm is proposed to optimize the power allocation between the local and relayed signals under the minimum BER criterion. Based on the OPA algorithm, a partner choice strategy is proposed to determine the partner locations specified by various cooperation gains. Simulation results show that the proposed resource optimization algorithms are superior to the unoptimized algorithms by significantly reducing the BER and improving the cooperative gain, which is useful to simplify the practical partner choice process.
文摘DNA fingerprints of 37 PVY resistant potato varieties （clones） were generated using PCR-based RAPD analysis. All 37 varieties were differentiated by banding patterns obtained from 17 primers that generated 164 polymorphisms. Similarity matrices were calculated with the simple matching coefficient. The genetic distance value among them was between 0.27 and 0.50, with average value being 0.35. The average link clustering algorithm was used to construct a dendrogram with Statistica. They were classified into three groups according to clustering results, and the results presented some geographic relationship. Dendrogram showed close genetic relationships between a number of varieties （clones） of similar pedigree. This study has shown that RAPD marker is a useful tool for potato variety identification, differentiation, and estimation of genetic relationships.
基金Supported by the National Natural Science Foundation of China (30871735 31272191)+2 种基金the National Key Technology R&D Program(2006BAD01A19-4-2)the Natural Science Foundation of Heilongjiang Province (C0207 C200619)
文摘A total of 69 random primers were screened by using random amplified polymorphic DNA （RAPD） markers to analyze the genetic bands of 32 Kentucky bluegrass cultivars. A total of 197 bands were amplified from 46 primers, among which 195 bands were polymorphic. Each primer could amplify one to nine polymorphic bands with an average of 4.3 per primer. Based on similarity coefficient analysis of RAPD results and by using NTSYS software to cluster analyze with the average UPGMA method, the result showed that 18 cultivars of the 32 were in group 1, three cultivars were in group 2, two cultivars were in group 3, eight cultivars were in group 4, and only one cultivar in group 5.
基金This research was supported by the grants from the National Natural Science Foundation of China(32072023)the Project of Sanya Yazhou Bay Science and Technology City(SCKJ-JYRC-2022-88).
文摘Background Plant pollen has diverse morphological characteristics that can be consistently passed down from generation to generation.Information on pollen morphology is thus immensely important for plant classification and identification.In the genus Gossypium,however,in-depth research on pollen morphology is lacking,with only few reports on limited cotton species.To evaluate the diversity of pollen in Gossypium,we therefore conducted a comprehensive analysis of the pollen morphology of 33 cotton species and varieties using scanning electron microscopy.Results The 33 analyzed cotton samples exhibited common pollen morphological features,including spherical shapes,radial symmetry,echination,panporation,and operculation,while the pollen size,spine shape,spine density and length showed distinctive features.Pollen size varied significantly among species,with diameters ranging from62.43 μm in G.harknessii to 103.41 μm in G.barbadense.The exine had an echinate sculptural texture,and spines were mostly conical or sharply conical but occasionally rod-like.Spine density varied from 173 in G.incanum to 54 in G.gossypioides,while spine length ranged from 3.53 μm in G.herbaceum to 9.47 μm in G.barbadense.In addition,the 33cotton species and varieties were grouped at a genetic distance of 3.83 into three clusters.Cluster Ⅰ comprised five allotetraploid AD-genome cotton species,four D-genome species,and one K-genome species.Cluster Ⅱ included 13diploid species from A,B,D,E,and G genomes,whereas Cluster Ⅲ only consisted one E-genome species G.incanum.Conclusions Although pollen characteristics alone are not enough to resolve taxonomic and systematic relationships within the genus Gossypium,our results add to knowledge on palynomorphology and contribute to phenological information on these taxa.Our findings should aid future systematic and phylogenetic studies of the Gossypium genus.
基金supported by the National Natural Science Foundation of China Agriculture(Grant No.2015NWB039)
文摘Background: Gossypium arboreum is a diploid species cultivated in the Old World. It possesses favorable characters that are valuable for developing superior cotton cultivars.Method: A set of 197 Gossypium arboreum accessions were genotyped using 80 genome-wide SSR markers to establish patterns of the genetic diversity and population structure. These accessions were collected from three major G. arboreum growing areas in China. A total of 255 alleles across 80 markers were identified in the genetic diversity analysis.Results: Three subgroups were found using the population structure analysis, corresponding to the Yangtze River Valley, North China, and Southwest China zones of G.arboreum growing areas in China. Average genetic distance and Polymorphic information content value of G. arboreum population were 0.34 and 0.47, respectively, indicating high genetic diversity in the G. arboreum germplasm pool. The Phylogenetic analysis results concurred with the subgroups identified by Structure analysis with a few exceptions. Variations among and within three groups were observed to be 13.61% and 86.39%, respectively.Conclusion: The information regarding genetic diversity and population structure from this study is useful for genetic and genomic analysis and systematic utilization of economically important traits in G. arboreum.
基金supported by the National Natural Science Foundation of China(61171101)the Fundamental Research Funds for the Central Universitiesthe 2014 Doctorial Innovation Fund of Beijing University of Posts and Telecommunications(CX201426)
文摘A novel practical codebook-precoding multiple-input multiple-output（MIMO） system based on signal space diversity（SSD） with the minimum mean squared error（MMSE）receiver is proposed.This scheme utilizes rotation modulation and space-time-frequency component interleaving.A novel precoding matrix selection criterion to maximize the average signal to interference plus noise ratio（SINR） is also put forward for the proposed scheme,which has a larger average mutual information（AMI）.Based on the AMI- maximization criterion,the optimal rotation angles for the proposed system are also investigated.The new scheme can make full use of space-time-frequency diversity and signal space diversity,and exhibit high spectral efficiency and high reliability in fading channels.Simulation results show that the proposed scheme greatly outperforms the conventional bit- interleaved coded modulation（BICM） MIMO-orthogonal frequency division multiplexing（OFDM） scheme without SSD,which is up to4.5 dB signal-to-noise ratio（SNR） gain.
文摘The phylogeny and diversity of two key functional genes were investigated as the basis for improved understanding of the community structure of natural phytoplankton assemblages in marine environments. New partial NR(encoding eukaryotic assimilatory nitrate reductase) and rbcL(encoding the large subunit of the ribulose-1,5-bisphosphate carboxylase/oxygenase) sequences from ten cultured phytoplankton strains are reported.Phytoplankton community com-
基金Supported by the National Nature Scienceof China(31571693)the National Soybean Industrial Technology System(CARS-04-04B)。
文摘Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the early breeding period;1971-1990,the mid-breeding period;and 1991-2010,the current breeding period)in northeast China were selected.Fourteen DNA-specified markers including cleaved amplified polymorphic sequences(CAPS),derived CAPS(d CAPS)and fragment length polymorphism(FLP)markers were filtered to analyze the genetic diversity from E1 to E4.The results were as the followings:the soybean varieties with more gene frequencies showed more gene diversities.Among the E genes,E1 and E3 genes showed more allelic diversities than E2,and E4 only had diversity in the early breeding period.During the artificial process,some alleles of E genes disappeared and some new ones were generated.More gene diversities were observed in soybean germplasms,and new excellent germplasms could be explored to improve yield traits in artificial breeding programs.Furthermore,six different E gene combinations were observed in the early breeding period,five in the mid-breeding period and 11 in the current breeding period.Three elite genotypes were identified through a century artificial selection,while new genotypes were also found in different breeding periods.Of them,e1-nle2e3-tr E4 was a new soybean genotype of extremely early maturity in the current breeding period,which was widely suitable for planting in 00 and 000 maturity groups.Moreover,significant correlation was found between E2 and E3,suggesting that light length and light quality were two key factors for soybean maturity in northeast China.The understanding of the E genes variation underlying soybean maturity could facilitate the procession to breed elite varieties adapted for diverse regions.
