Habitat fragmentation in forest ecosystems poses a major threat to biodiversity,disrupting ecological corridors,limiting gene flow,and threatening persistence,especially for forest-dependent species.Among these specie...Habitat fragmentation in forest ecosystems poses a major threat to biodiversity,disrupting ecological corridors,limiting gene flow,and threatening persistence,especially for forest-dependent species.Among these species,woodland specialist bryophytes represent one of the most endangered groups,with Dicranum viride,an epiphytic moss of high conservation value protected under international regulations,exemplifying this conservation concern.Despite its legal status,the factors that influence its genetic connectivity and dispersal potential remain poorly understood.In this study,we integrated molecular analyses based on genome-wide single-nucleotide polymorphism(SNP)markers with spatial modelling,including least-cost path(LCP)analyses and circuit-based connectivity models,to assess the impact of forest continuity and management on the genetic structure and ecological corridors of D.viride across temperate forest ecosystems of Central Europe.Our results revealed a complex dispersal dynamic that combines short-distance clonal propagation with rare long-distance dispersal events.Genetic clustering analyses indicated that long-term forest continuity supports unique genetic lineages.LCP analyses and circuit-based connectivity models demonstrated that naturally regenerating forests(reflecting management regime)and forests with long-term continuity(reflecting habitat age and historical stability)provide dispersal corridors with the highest habitat permeability.Our findings highlight the critical role of long-term habitat stability in maintaining the genetic diversity and population dynamics of D.viride.Conservation strategies should prioritise the protection of mature forests,the maintenance of ecological corridors,and the integration of retention forestry practices to support epiphytic bryophytes.Our study improves the understanding of how landscape connectivity influences the persistence of rare epiphytic bryophytes,offering practical insights for the conservation of biodiversity and sustainable forest management.展开更多
Background As an important genetic resource of chickens,gamecock has unique morphological and behavioral characteristics such as large size,muscular development and strong aggression,making it a good model for studyin...Background As an important genetic resource of chickens,gamecock has unique morphological and behavioral characteristics such as large size,muscular development and strong aggression,making it a good model for studying muscle development and behavior patterns,as well as an excellent breeding material.Gamecocks are distributed worldwide,forming different breeds and strains.However,the single or multiple origin of global gamecocks has not been fully established and much remains unknown about genetic introgression events between gamecocks and other chickens.Therefore,in this study,based on whole genome data of gamecocks,Chinese indigenous chickens,commercial chickens and wild jungle fowls,we performed population structure analysis,selection signal analysis,and genomic introgression analysis of gamecocks.Results The population structure analysis revealed that gamecocks have multiple origins.In addition,we used Fst,π-Ratio and XP-EHH methods to explore the candidate signatures of positive selection in gamecocks.A total number of fifteen shared candidate genes were identified using the three different detection strategies.Among these candidate genes,ETV1,DGKB,AGMO,MEOX2,ISPD and PLCB4 are related to the growth and muscle development,fighting performance and neurodevelopment of gamecocks.Furthermore,we detected the introgression event at the MYBPHL region from the Gallus sonneratii into Euramerican gamecocks and at the CPZ gene region from the Gallus gallus gallus into multiple gamecock populations,respectively,indicating the introgression from the wild junglefowl may impact the skeletal and muscle development as well as aggressive behavior of gamecocks.Conclusions In summary,we conducted a genome-wide exploration of gamecocks from multiple regions worldwide.Our analysis confirmed multiple origins of gamecocks and detected several candidate genes that are possibly related to important traits and characteristics in gamecocks.More importantly,this is the first study that has detected introgression events and genes from wild jungle fowls to gamecocks,which provides evidence of the wild jungle fowls contributing to the genetic diversity of gamecocks.Our findings offer new perspectives on the impact of introgression on gamecocks,and provide a basis for further resource conservation and utilization of gamecock,as well as provide excellent material for the genetic improvement of domestic chickens.展开更多
Microsatellite markers with polymorphic advantages are widely used in the exploration and utilization of marine fishery resources.In this study,16 polymorphic microsatellite markers were used to evaluate the diversity...Microsatellite markers with polymorphic advantages are widely used in the exploration and utilization of marine fishery resources.In this study,16 polymorphic microsatellite markers were used to evaluate the diversity and population structure of Setipinna tenuifilis,a nearshore fish of economic and ecological value in the western Pacific Ocean and Indian Ocean.The genetic diversity of S.tenuifilis showed a high level[mean Na(number of alleles)is 23.25,mean Ho(observed heterozygosity)is 0.639,mean R_(a)(allelic richness)is 11.625,and the polymorphic information content(PIC)is 0.844]similar to other Clupeiformes fish species.The nine wild S.tenuifilis populations showed significant differentiation(F_(ST)ranging from 0.00384 to 0.19346)and were generally divided into southern and northern populations based on genetic structure,except for the Zhoushan population,which exhibited genetic mixture.Our results provide fundamental but significant genetic insights for the management and conservation of S.tenuifilis fishery resources.展开更多
This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length(total length, AT) and sexual matu...This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length(total length, AT) and sexual maturity stages of Antarctic krill(Euphausia superba) were examined. The age structure and geographic distribution of cluster groups also were studied. The results reveal significant diurnal variations in the length and maturity stages of Antarctic krill during the morning(MRN) to morning twilight(MTW) period, with mean lengths ranging from 28.92 to 45.87 mm. Two cyclical patterns were observed.Regarding maturity stages, the krill were composed of juveniles, adult males, and adult females in increasing order of proportion,with a notably higher proportion of non-gravid females compared to gravid females, and mainly distributed in evening twilight(ETW) to dawn(DWN), MTW to day(DAY), MRN to MTW, MRN to MTW and night(NIT) to DAY periods, respectively.Significant spatial variations in krill length and maturity stages occur, with a marked regional boundary around 130°W. K-means clustering analysis of krill length identified Group Ⅰ, Group Ⅱ, and Group Ⅲ, with dominant age classes of 3+, 0 and 3+, and 3+to 4+, respectively. Group Ⅱ was widely distributed in the surveyed waters, whereas Group Ⅰ and Group Ⅲ were distributed only in waters west of 130°W. The study area features a significant continental slope, where adults and gravid females were primarily distributed on its slopes and to the south. This spatial pattern also profoundly influenced the distribution of different cluster groups.展开更多
We used sequences of mitochondrial control region （807bp） in 75 samples from three breeding colonies and one wintering population to investigate the genetic diversity and population structure of Marsh Grassbird （Lo...We used sequences of mitochondrial control region （807bp） in 75 samples from three breeding colonies and one wintering population to investigate the genetic diversity and population structure of Marsh Grassbird （Locustella pryeri sinensis） in different regions of China. Marsh Grassbird retained a moderate amount of haplotype （0.759 ± 0.056） and nucleotide diversity （0.002）. The results of FST among 3 phy-logeographic units and ФST between breeding and wintering sites revealed little evidence of genetic distinction between different colonies. Neither UPGMA tree structure analysis nor Network picture analysis showed obvious divergence between populations at different locations. Analysis of molecular variance also showed a lack of regional subdivision within Locustella pryeri sinesis, 98.5% of source of variation within populations and only 1.5% among populations. The neutrality test showed negative Fu’s FS value, which, in combination with detection of the mismatch distribution, suggested that population expansion occurred in the evolu-tionary history of this species. This hypothesis was further supported by Tajima’s D test and Fu’s test （D = -1.80, p = 0.02; Fs = -22.11, p = 0.001）, this expansion was estimated to occur about 28,700 years ago.展开更多
In this study, 34 molecular markers of starch synthesis-related genes were used to evaluate the genetic variation and population structure of 87 indica rice cultivars from different countries and regions. The results ...In this study, 34 molecular markers of starch synthesis-related genes were used to evaluate the genetic variation and population structure of 87 indica rice cultivars from different countries and regions. The results showed that a total of 80 alleles were amplified using 34 primer pairs, with an average of 2.5 alleles per locus. The allele number varied from 2 to 6 among various cultivars. Shannon＇s diversity index of molecular markers varied from 0.303 to 0.796, with an average of 0.539. Polymorphism information content （PIC） varied from 0.084 to 0.658, with an average of 0.295. The genetic similarity coefficients of 87 indica rice cultivars ranged from 0.265 to 0.990, indicating significant genetic differences of starch synthesis-related genes among different cultivars, but the variation frequency of alleles varied among different cultivars. Population structure analysis showed that these 87 indica rice cultivars were divided into three categories. Genetic differences were small within the same category but great among different categories. Moreover, indica rice cultivars with simple genetic components accounted for 39.1% and those with complex genetic background accounted for 60.9%. This study may not only provide theoretical basis for genetic improvement of rice starch quality, but also lay a solid foundation for subsequent association analysis of rice quality-related traits.展开更多
Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones （EEZ） during 2008-2010. E...Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones （EEZ） during 2008-2010. Estimated ages ranged from 144 to 633 days, confirming that the squid is a short-lived species with longevity no longer than 2 years. Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round. Back-calculated hatching dates for the samples were from January 22^nd, 2008 to April 22nd, 2010 with a peak between January and March. Two size-based and two hatching date-based populations could be defined from mantle length （ML） at maturity and back-calculated hatching dates, respectively. Females matured at a larger size than males, and there was a significant difference in ML at maturity between the two hatching groups （P〈0.05）. The waters adjacent to 1 l^S off the Peruvian EEZ may be a potential spawning ground. This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ, which should be considered in the assessment and management of this important resource.展开更多
Chinese mitten crab （Eriocheir sinensis） has higher commercial value as food source than any other species of Eriocheir in China. To evaluate the germplasm resources and characterize the genetic diversity and popula...Chinese mitten crab （Eriocheir sinensis） has higher commercial value as food source than any other species of Eriocheir in China. To evaluate the germplasm resources and characterize the genetic diversity and population structure of the crabs in different water systems, two stocks and two farming populations were assessed with 25 polymorphic microsallite loci available in public GenBank. Basic statistics showed that the average observed heterozygosity （Ho） amongst populations ranged from 0.5789 to 0.6824. However, a remarkable presence of inbreeding and heterozygote deficiencies were observed. To analyze population structure, pairwise FST coefficients explained only -10.3% variability from the subdivision of mitten crab populations, the remaining variability stems from the subdivision within subpopulations. Although the four populations had slight differentiation, different allelic frequencies resulted in distinct population structures. Two stocks and one farming population were clustered together to the phylogenetic branch of Yangtze crab, with an approximate membership of 95%. Whereas, another farming population was clustered singly to the phylogenetic branch of the Liaohe crab, with a membership of 97.1%. The tests for individual admixture showed that Yangtze crab had probably been contaminated with individuals from other water systems. Genetic relationships between populations also supported the conclusion that Yangtze crab and Liaohe crab had different gene pools in spite of the origins of the same species.展开更多
Sweetpotato, Ipomoea batatas（L.） Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of g...Sweetpotato, Ipomoea batatas（L.） Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of genetic diversity in the existing germplasm resources. In the present study, a collection of 380 sweetpotato accessions assembled from different agro-climatic zones of China and other countries were genotyped using 30 SSR primer pairs. Model-based structure analysis separated the germplasm into three populations, P1, P2 and P3, containing 228, 133 and 19 accessions, respectively, which was consistent with the results of phylogenic and principal component analysis（PCA）. Analysis of molecular variance（AMOVA） revealed significant genetic differentiation among inferred populations, accounting for 16.47% of the total molecular variance, however, the differences between the regions were not significant, the total variation were due to the differences between the genotypes within the population. Pairwise fixation index（F ST） suggested that populations P1 and P3 had the highest differentiation, while populations P1 and P2 had the lowest differentiation. The diversity among populations was wide, which confirmed the genetic distinction of populations. Through comparing model-based structure and domestication-based classification, it was found that the accessions of population P1 mainly belonged to modern cultivars, and the accessions of populations P2 and P3 basically corresponded to landraces, by which we suggest that modern cultivars maybe had experienced a two-step domestication history. Our results illustrated clear genetic relationships among 380 sweetpotato accessions, exhibiting the potential of accelerating the process of future sweetpotato breeding program by molecular marker based parental selection.展开更多
One hundred and nine Malus sieversii accessions from four geographical populations located at Kuerdening in Mohe town,Gongliu County,Jiaowutuohai,in Xinyuan County,Daxigou in Houcheng County of Ily State,and Baerluke ...One hundred and nine Malus sieversii accessions from four geographical populations located at Kuerdening in Mohe town,Gongliu County,Jiaowutuohai,in Xinyuan County,Daxigou in Houcheng County of Ily State,and Baerluke Mountain in Yumin County of Tacheng State,Xinjiang Uygur Autonomous Region of China were studied by SSR markers.The purpose of the study was to determine the genetic structure and diversity in these eco-geographical populations with eight pair SSR primers of apple.The results indicated that:an average of 16 bands was detected in the four populations.The percentage of polymorphic bands in Gongliu population(89.06%)was the highest in the four populations.The average Nei's gene diversity index was 0.257 for all the loci.Totally,128 polymorphic loci were detected and the percentage of polymorphic loci(P)was 100%,88.28%,84.83%,87.50%,and 87.12%,respectively,at the species level and Gongliu,Xinyuan,Huocheng,and Yumin population levels.The Nei's gene diversity index(H=0.2619)and Shannon's information index(1=0.4082)in the species level were higher than in the population level.The Nei's gene diversity index and Shannon's information index in the four populations were Gongliu〉Huocheng〉Xinyuan〉Yumin.Gongliu population and Xinyuan population were the highest in genetic identity and the closest in genetic distance.Gene flow between the populations was 7.265 based on genetic differentiation coefficient(GST=0.064).The UPGMA cluster analysis indicated that the genetic relationships between the Gongliu and Xinyuan population were the closest,and the Yumin population were the farthest with the other three populations.The UPGMA cluster analysis indicated that the four geographical populations located in Gongliu,Xinyuan,Huocheng,and Yumin were relatively independent populations.Concurrently,there was also mild gene exchange between the populations.On the basis of the study of population genetic structure and the highest genetic diversity,Gongliu population should be given a high priority consideration in Malus sieversii population's in situ germplasm conservation.展开更多
An investigation was conducted on distribution pattern, site condition and population structure of yew Taxus cuspidata Sieb. et Zucc. in Muling Forest Bureau of Heilongjiang Province, China in April, 2005. Results sho...An investigation was conducted on distribution pattern, site condition and population structure of yew Taxus cuspidata Sieb. et Zucc. in Muling Forest Bureau of Heilongjiang Province, China in April, 2005. Results showed that yew is mainly distributed under the main storey of natural mixed forest of conifer and broadleaf, the soil moisture content of the yew site is high （40%-60%）, the pH value of soil is relatively lower （4.7-5.5）, and that the population structure of wild yew is not rational, belonging to the degeneration population, which is one of the reasons leading to the population decline. Although the site conditions of Muling area are suitable for the growth of wild yew, the population of wild yew shows a decline tendency, due to the fact that the middle-sized adult yew trees have been cut, young yews are often grazed by wildlife, and that the trunks of adult yew tend to be hollow.展开更多
Nine Chinese yak breeds （Maiwa, Tianzhu White, Qinghai Plateau, Sibu, Zhongdian, Pali, Tibetan High Mountain, Jiulong, and Xinjiang） and Gayal were analyzed by means of 16 microsatellite markers to determine the lev...Nine Chinese yak breeds （Maiwa, Tianzhu White, Qinghai Plateau, Sibu, Zhongdian, Pali, Tibetan High Mountain, Jiulong, and Xinjiang） and Gayal were analyzed by means of 16 microsatellite markers to determine the level of genetic variation within populations, genetic relationship between populations, and population structure for each breed. A total of 206 microsatellite alleles were observed. Mean F-statistics （0.056） for 9 yak breeds indicated that 94.4% of the genetic variation was observed within yak breeds and 5.6% of the genetic variation existed amongst breeds. The Neighbor-Joining phylogenetic tree was constructed based on Nei＇s standard genetic distances and two clusters were obtained. The Gayal separated from the yaks far away and formed one cluster and 9 yak breeds were grouped together. The analysis of population structure for 9 yak breeds and the Gayal showed that they resulted in four clusters; one cluster includes yaks from Tibet Autonomous Region and Qinghai Province, one cluster combines Zhongdian, Maiwa, and Tianzhu White, and Jiulong and Xinjiang come into the third cluster. Pali was mainly in the first cluster （90%）, Jiulong was mainly in the second cluster （87.1%）, Zhongdian was primarily in the third cluster （83%）, and the other yak breeds were distributed in two to three clusters. The Gayal was positively left in the fourth cluster （99.3%）.展开更多
Since 2000, the Chinese government has implemented emergency water diversion measures to restore the damaged riparian forest ecosystem with dominant tree species Euphrat poplar(Populus euphratica Oliv.)at the lower re...Since 2000, the Chinese government has implemented emergency water diversion measures to restore the damaged riparian forest ecosystem with dominant tree species Euphrat poplar(Populus euphratica Oliv.)at the lower reaches of the Tarim River. In the present study, comparative analysis of variations in the vitality of P. euphratica trees were made using 2005 and 2010 data to illustrate the revitalization process of riparian forest. Poplar trees within 300 m of the riverbed were positively revitalized, while the vitality of trees farther than 300 m from the river decreased. Population structure was studied to demonstrate the development of poplar community. In the first belt, the class structure for the diameter at breast height(DBH) of P. euphratica fit a logistic model, and the 2nd, 3rd and 4th belt curve fittings were close to a Gaussian model; in other plots they were bimodal. Cluster analysis of the composition of the DBH class of poplar trees demonstrated that those within 16–36 cm DBH were the most abundant(58.49% of total) in study area, under 16 cm of DBH were second(31.36%), and trees >40 cm DBH were the least abundant(10.15%). More than 80% of the trees were young and medium-sized, which means that the poplar forest community in the vicinity of the lower Tarim River is at a stable developmental stage. The abundance of juvenile trees of P. euphratica in the first and second measuring belts was 12.13% in 2005 and increased to 25.52% in 2010, which means that the emergency water transfer had a positive impact on the generation of young P. euphratica trees in the vicinity of the river.展开更多
To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The ...To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity （GS） values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions （0.447）, while Australia accessions have the furthest distance （0.503）. A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.展开更多
Three Epimedium species,E.pubescens Maxim.,E.sagittatum(Sieb.&Zucc.)Maxim.,and E.wushanense T.S.Ying,which are sympatrically distributed in the western Hubei Province,have been used in traditional Chinese medicine...Three Epimedium species,E.pubescens Maxim.,E.sagittatum(Sieb.&Zucc.)Maxim.,and E.wushanense T.S.Ying,which are sympatrically distributed in the western Hubei Province,have been used in traditional Chinese medicine(TCM)for about 2,000 years.Genetic variability and population genetic structure of 11 natural populations of these Epimedium species were investigated using isoelectric focusing in thin-layer polyacrylamide slab gels.Of the 22 enzyme systems prescreened,six coding for 13 loci and 45 alleles were resolved,which were used for analyzing genetic diversity and population structure at both intraspecific and interspecific levels.The results showed that:l)high levels of genetic diversity were observed in all three species(A=2.6-3.2,P=69.2%-84.6%,Ho=0.274-0.377,HE=0.282-0.369),which were higher than that of other herbaceous and aulmal-pollinated species with similar life-history characteristics;2)there was significant deviation from Hardy-Weinberg Equilibrium,with one half of the loci showing heterozygote excess and the other homozygote excess,in all populations,suggesting the complicated breeding system of Epimedium species;3)the low level of intraspecific and interspecific genetic differentiation(GST=0.0246-0.0409 and 0.0495-0.1213,respectively)indicated a high level of gene flow among populations and close genetic relationship among the three species;and 4)UPGMA cluster analysis further showed that E.pubescens was more closely related to E.sagittatum than to E.wushanense,which was in good agreement with the morphological characters and the recent phylogenetic analysis of these species.On the basis of these results,it was concluded that the mixed breeding system,long-lived perennial life form,ancient evolutionary history,and seed dispersal by ants in Epimedium are responsible for the genetic variation and population structure of these species.展开更多
To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on sin...To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on single nucleotide polymorphism(SNP)markers.Ten pairs of primers with good polymorphism and high resolution were screened from 315 pairs of SNP primers by 3 broccoli accessions(inbred lines)with different phenotypes and maturity.The 10 pairs of SNP primers were selected,producing 78 alleles.The diversity analysis indicated that the polymorphism information content(PIC)of SNP primer ranged from 0.64 to 0.90.The observed number of alleles(Na)was 2.00,the effective number of alleles(Ne)was 1.11–2.00,the Nei’s gene diversity(H)was 0.10–0.50,and Shannon information index(I)was 0.20–0.70 using PopGene32 software.The clustering results showed that the 161 broccoli cultivars could be divided into 4 major subgroups(A,B,C and D),foreign cultivars were all assigned to subgroup A,and domestic cultivars were assigned to 3 subgroups of B,C,and D.This study indicated that some domestic cultivars and foreign cultivars were similar in genetic background,but most domestic cultivars were still different from the Japanese cultivars.When K=2,the population structure result presented that 161 broccoli cultivars could be divided into 1 simple group(2 groups)and 1 mixed group.When Q≥0.6,143(88.82%)broccoli cultivars belonged to the simple groups.In simple groups 68(42.24%)broccoli cultivars of group 1 were derived from Japan,the United States,Switzerland,the Netherlands,China-Taiwan,and China-Mainland;75(46.58%)broccoli cultivars belonged to group 2;when Q<0.6,18(11.18%)broccoli cultivars belonged to the mixed groups.This study is helpful to understand the diversity and resolution of broccoli cultivars from worldwide,which is beneficial to plant breeding and materials innovation.And meanwhile,this result is also used for construction of broccoli fingerprint serving for cultivar identification.展开更多
Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and ef...Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and effectively use them in the genetic improvement. In this study, the genetic diversity of 617 sweetpotato accessions, including 376landraces and 162 bred varieties from China and 79 introduced varieties from 11 other countries, was assessed using 30 simple sequence repeat(SSR) primer pairs with high polymorphism. Based on the population structure analysis,these sweetpotato accessions were divided into three groups, Group 1, Group 2 and Group 3, which included 228, 136and 253 accessions, respectively. Consistent results were obtained by phylogenic analysis and principal coordinate analysis(PCoA). Of the three groups, Group 2 showed the highest level of genetic diversity and its accessions were mainly distributed in low-latitude regions. The accessions from South China exhibited the highest level of genetic diversity, which supports the hypothesis that Fujian and Guangdong were the first regions where sweetpotato was introduced to China. Analysis of molecular variance(AMOVA) indicated significant genetic differentiations between the different groups, but low levels of genetic differentiation existed between the different origins and accession types.These results provide valuable information for the better utilization of these accessions in sweetpotato breeding.展开更多
Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important fo...Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I （COl） gene. A total of 76 specimens were collected from three localities around the East （Qidong and Zhoushan） and South China Seas （Zhuhai）. Among these individuals, nine polymorphic sites were detected and 1 l distinct haplotypes were defined. High levels ofhaplotype diversity （h=0.759i0.035） and low levels of nucleotide diversity （re=0.001 98i0.003 26） were observed in these populations, Hierarchical analysis of molecular variance （AMOVA） indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant （~0~t=0.032 85, P〈0.01）. These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.展开更多
基金supported by the Wrocław University of Environmental and Life Sciences(Poland)as the Ph.D.research programme“Bon doktoranta SD UPWr”N020/0002/22.
文摘Habitat fragmentation in forest ecosystems poses a major threat to biodiversity,disrupting ecological corridors,limiting gene flow,and threatening persistence,especially for forest-dependent species.Among these species,woodland specialist bryophytes represent one of the most endangered groups,with Dicranum viride,an epiphytic moss of high conservation value protected under international regulations,exemplifying this conservation concern.Despite its legal status,the factors that influence its genetic connectivity and dispersal potential remain poorly understood.In this study,we integrated molecular analyses based on genome-wide single-nucleotide polymorphism(SNP)markers with spatial modelling,including least-cost path(LCP)analyses and circuit-based connectivity models,to assess the impact of forest continuity and management on the genetic structure and ecological corridors of D.viride across temperate forest ecosystems of Central Europe.Our results revealed a complex dispersal dynamic that combines short-distance clonal propagation with rare long-distance dispersal events.Genetic clustering analyses indicated that long-term forest continuity supports unique genetic lineages.LCP analyses and circuit-based connectivity models demonstrated that naturally regenerating forests(reflecting management regime)and forests with long-term continuity(reflecting habitat age and historical stability)provide dispersal corridors with the highest habitat permeability.Our findings highlight the critical role of long-term habitat stability in maintaining the genetic diversity and population dynamics of D.viride.Conservation strategies should prioritise the protection of mature forests,the maintenance of ecological corridors,and the integration of retention forestry practices to support epiphytic bryophytes.Our study improves the understanding of how landscape connectivity influences the persistence of rare epiphytic bryophytes,offering practical insights for the conservation of biodiversity and sustainable forest management.
基金supported by the National Key Research and Development Program of China(2024YFF1001400)the Open Project of State Key Laboratory of Animal Biotech Breeding(2024SKLAB6-106)Fundamental Research Funds for Central University(7110100870).
文摘Background As an important genetic resource of chickens,gamecock has unique morphological and behavioral characteristics such as large size,muscular development and strong aggression,making it a good model for studying muscle development and behavior patterns,as well as an excellent breeding material.Gamecocks are distributed worldwide,forming different breeds and strains.However,the single or multiple origin of global gamecocks has not been fully established and much remains unknown about genetic introgression events between gamecocks and other chickens.Therefore,in this study,based on whole genome data of gamecocks,Chinese indigenous chickens,commercial chickens and wild jungle fowls,we performed population structure analysis,selection signal analysis,and genomic introgression analysis of gamecocks.Results The population structure analysis revealed that gamecocks have multiple origins.In addition,we used Fst,π-Ratio and XP-EHH methods to explore the candidate signatures of positive selection in gamecocks.A total number of fifteen shared candidate genes were identified using the three different detection strategies.Among these candidate genes,ETV1,DGKB,AGMO,MEOX2,ISPD and PLCB4 are related to the growth and muscle development,fighting performance and neurodevelopment of gamecocks.Furthermore,we detected the introgression event at the MYBPHL region from the Gallus sonneratii into Euramerican gamecocks and at the CPZ gene region from the Gallus gallus gallus into multiple gamecock populations,respectively,indicating the introgression from the wild junglefowl may impact the skeletal and muscle development as well as aggressive behavior of gamecocks.Conclusions In summary,we conducted a genome-wide exploration of gamecocks from multiple regions worldwide.Our analysis confirmed multiple origins of gamecocks and detected several candidate genes that are possibly related to important traits and characteristics in gamecocks.More importantly,this is the first study that has detected introgression events and genes from wild jungle fowls to gamecocks,which provides evidence of the wild jungle fowls contributing to the genetic diversity of gamecocks.Our findings offer new perspectives on the impact of introgression on gamecocks,and provide a basis for further resource conservation and utilization of gamecock,as well as provide excellent material for the genetic improvement of domestic chickens.
基金The Zhejiang Provincial Natural Science Foundation of China under contract Nos LY22D060001 and LY20C190008the National Natural Science Foundation of China(NSFC)under contract No.41806156the Key Research and Development Projects in Xizang under contract No.XZ202301ZY0012N.
文摘Microsatellite markers with polymorphic advantages are widely used in the exploration and utilization of marine fishery resources.In this study,16 polymorphic microsatellite markers were used to evaluate the diversity and population structure of Setipinna tenuifilis,a nearshore fish of economic and ecological value in the western Pacific Ocean and Indian Ocean.The genetic diversity of S.tenuifilis showed a high level[mean Na(number of alleles)is 23.25,mean Ho(observed heterozygosity)is 0.639,mean R_(a)(allelic richness)is 11.625,and the polymorphic information content(PIC)is 0.844]similar to other Clupeiformes fish species.The nine wild S.tenuifilis populations showed significant differentiation(F_(ST)ranging from 0.00384 to 0.19346)and were generally divided into southern and northern populations based on genetic structure,except for the Zhoushan population,which exhibited genetic mixture.Our results provide fundamental but significant genetic insights for the management and conservation of S.tenuifilis fishery resources.
基金supported by the 38th and 39th CHINAREs and all members of the two Antarctic cruisessupported by Ministry of Natural Resources of the People’s Republic of China and the Chinese Arctic and Antarctic Administration。
文摘This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length(total length, AT) and sexual maturity stages of Antarctic krill(Euphausia superba) were examined. The age structure and geographic distribution of cluster groups also were studied. The results reveal significant diurnal variations in the length and maturity stages of Antarctic krill during the morning(MRN) to morning twilight(MTW) period, with mean lengths ranging from 28.92 to 45.87 mm. Two cyclical patterns were observed.Regarding maturity stages, the krill were composed of juveniles, adult males, and adult females in increasing order of proportion,with a notably higher proportion of non-gravid females compared to gravid females, and mainly distributed in evening twilight(ETW) to dawn(DWN), MTW to day(DAY), MRN to MTW, MRN to MTW and night(NIT) to DAY periods, respectively.Significant spatial variations in krill length and maturity stages occur, with a marked regional boundary around 130°W. K-means clustering analysis of krill length identified Group Ⅰ, Group Ⅱ, and Group Ⅲ, with dominant age classes of 3+, 0 and 3+, and 3+to 4+, respectively. Group Ⅱ was widely distributed in the surveyed waters, whereas Group Ⅰ and Group Ⅲ were distributed only in waters west of 130°W. The study area features a significant continental slope, where adults and gravid females were primarily distributed on its slopes and to the south. This spatial pattern also profoundly influenced the distribution of different cluster groups.
基金supported by National Natural Science Foundation of China (No. 130370221 and No. 30770309)
文摘We used sequences of mitochondrial control region （807bp） in 75 samples from three breeding colonies and one wintering population to investigate the genetic diversity and population structure of Marsh Grassbird （Locustella pryeri sinensis） in different regions of China. Marsh Grassbird retained a moderate amount of haplotype （0.759 ± 0.056） and nucleotide diversity （0.002）. The results of FST among 3 phy-logeographic units and ФST between breeding and wintering sites revealed little evidence of genetic distinction between different colonies. Neither UPGMA tree structure analysis nor Network picture analysis showed obvious divergence between populations at different locations. Analysis of molecular variance also showed a lack of regional subdivision within Locustella pryeri sinesis, 98.5% of source of variation within populations and only 1.5% among populations. The neutrality test showed negative Fu’s FS value, which, in combination with detection of the mismatch distribution, suggested that population expansion occurred in the evolu-tionary history of this species. This hypothesis was further supported by Tajima’s D test and Fu’s test （D = -1.80, p = 0.02; Fs = -22.11, p = 0.001）, this expansion was estimated to occur about 28,700 years ago.
基金Supported by Agricultural Science and Technology Independent Innovation Fund of Jiangsu Province[CX(14)5107]Science and Technology Support Program of Jiangsu Province(BE2015355)Special Fund for Construction of Modern Agricultural Industry Technology System(CARS-01-47)~~
文摘In this study, 34 molecular markers of starch synthesis-related genes were used to evaluate the genetic variation and population structure of 87 indica rice cultivars from different countries and regions. The results showed that a total of 80 alleles were amplified using 34 primer pairs, with an average of 2.5 alleles per locus. The allele number varied from 2 to 6 among various cultivars. Shannon＇s diversity index of molecular markers varied from 0.303 to 0.796, with an average of 0.539. Polymorphism information content （PIC） varied from 0.084 to 0.658, with an average of 0.295. The genetic similarity coefficients of 87 indica rice cultivars ranged from 0.265 to 0.990, indicating significant genetic differences of starch synthesis-related genes among different cultivars, but the variation frequency of alleles varied among different cultivars. Population structure analysis showed that these 87 indica rice cultivars were divided into three categories. Genetic differences were small within the same category but great among different categories. Moreover, indica rice cultivars with simple genetic components accounted for 39.1% and those with complex genetic background accounted for 60.9%. This study may not only provide theoretical basis for genetic improvement of rice starch quality, but also lay a solid foundation for subsequent association analysis of rice quality-related traits.
基金Supported by the National Natural Science Foundation of China (No.41276156)the National High Technology Research and Development Program of China (863 Program) (No. 2012AA092303)+3 种基金the Innovation Program of Shanghai Municipal Education Commission (No. 13YZ091)Shanghai Leading Academic Disciplin Projectsupported by National Distant-Water Fisheries Engineering Research Center, and Scientific Observing and Experimental Station of Oceanic Fishery Resources, Ministry of AgricultureYong Chen’s involvement in the project was supported by the Shanghai Dongfang Scholar Program
文摘Age, maturation and population structure of the Humboldt squid Dosidicus gigas were studied based on random sampling of the Chinese jigging fishery off the Peruvian Exclusive Economic Zones （EEZ） during 2008-2010. Estimated ages ranged from 144 to 633 days, confirming that the squid is a short-lived species with longevity no longer than 2 years. Occurrence of mature females and hatching in each month indicated that Humboldt squid spawned year-round. Back-calculated hatching dates for the samples were from January 22^nd, 2008 to April 22nd, 2010 with a peak between January and March. Two size-based and two hatching date-based populations could be defined from mantle length （ML） at maturity and back-calculated hatching dates, respectively. Females matured at a larger size than males, and there was a significant difference in ML at maturity between the two hatching groups （P〈0.05）. The waters adjacent to 1 l^S off the Peruvian EEZ may be a potential spawning ground. This study shows the complexity of the population structure and large variability in key life history parameters in the Humboldt squid off the Peruvian EEZ, which should be considered in the assessment and management of this important resource.
文摘Chinese mitten crab （Eriocheir sinensis） has higher commercial value as food source than any other species of Eriocheir in China. To evaluate the germplasm resources and characterize the genetic diversity and population structure of the crabs in different water systems, two stocks and two farming populations were assessed with 25 polymorphic microsallite loci available in public GenBank. Basic statistics showed that the average observed heterozygosity （Ho） amongst populations ranged from 0.5789 to 0.6824. However, a remarkable presence of inbreeding and heterozygote deficiencies were observed. To analyze population structure, pairwise FST coefficients explained only -10.3% variability from the subdivision of mitten crab populations, the remaining variability stems from the subdivision within subpopulations. Although the four populations had slight differentiation, different allelic frequencies resulted in distinct population structures. Two stocks and one farming population were clustered together to the phylogenetic branch of Yangtze crab, with an approximate membership of 95%. Whereas, another farming population was clustered singly to the phylogenetic branch of the Liaohe crab, with a membership of 97.1%. The tests for individual admixture showed that Yangtze crab had probably been contaminated with individuals from other water systems. Genetic relationships between populations also supported the conclusion that Yangtze crab and Liaohe crab had different gene pools in spite of the origins of the same species.
基金supported by the Hubei Engineering and Technology Research Centre of Sweetpotato,Chinathe International Cooperation Program,Ministry of Science and Technology of China (2011DFB31620)+3 种基金the Introduction and Utiliztion of Sweetpotato Resources in USA (2013-Z61)the Characteristic Discipline of Hubei Academy of Agricultural Sciences,Chinathe Science and Technology Innovation Centre of Hubei Academy of Agricultural Sciences,China (2007-620-001-03)the China Agriculture Research System (CARS-11-C-15)
文摘Sweetpotato, Ipomoea batatas（L.） Lam., is an important food crop widely cultivated in the world. Evaluation of genetic relationships among diverse cultivars and landraces is necessary for efficient exploitation of genetic diversity in the existing germplasm resources. In the present study, a collection of 380 sweetpotato accessions assembled from different agro-climatic zones of China and other countries were genotyped using 30 SSR primer pairs. Model-based structure analysis separated the germplasm into three populations, P1, P2 and P3, containing 228, 133 and 19 accessions, respectively, which was consistent with the results of phylogenic and principal component analysis（PCA）. Analysis of molecular variance（AMOVA） revealed significant genetic differentiation among inferred populations, accounting for 16.47% of the total molecular variance, however, the differences between the regions were not significant, the total variation were due to the differences between the genotypes within the population. Pairwise fixation index（F ST） suggested that populations P1 and P3 had the highest differentiation, while populations P1 and P2 had the lowest differentiation. The diversity among populations was wide, which confirmed the genetic distinction of populations. Through comparing model-based structure and domestication-based classification, it was found that the accessions of population P1 mainly belonged to modern cultivars, and the accessions of populations P2 and P3 basically corresponded to landraces, by which we suggest that modern cultivars maybe had experienced a two-step domestication history. Our results illustrated clear genetic relationships among 380 sweetpotato accessions, exhibiting the potential of accelerating the process of future sweetpotato breeding program by molecular marker based parental selection.
基金the National Natural Science Foundation of China(No.30471196)the Special Program for Doctorial Site of Universities(No.200404344011).
文摘One hundred and nine Malus sieversii accessions from four geographical populations located at Kuerdening in Mohe town,Gongliu County,Jiaowutuohai,in Xinyuan County,Daxigou in Houcheng County of Ily State,and Baerluke Mountain in Yumin County of Tacheng State,Xinjiang Uygur Autonomous Region of China were studied by SSR markers.The purpose of the study was to determine the genetic structure and diversity in these eco-geographical populations with eight pair SSR primers of apple.The results indicated that:an average of 16 bands was detected in the four populations.The percentage of polymorphic bands in Gongliu population(89.06%)was the highest in the four populations.The average Nei's gene diversity index was 0.257 for all the loci.Totally,128 polymorphic loci were detected and the percentage of polymorphic loci(P)was 100%,88.28%,84.83%,87.50%,and 87.12%,respectively,at the species level and Gongliu,Xinyuan,Huocheng,and Yumin population levels.The Nei's gene diversity index(H=0.2619)and Shannon's information index(1=0.4082)in the species level were higher than in the population level.The Nei's gene diversity index and Shannon's information index in the four populations were Gongliu〉Huocheng〉Xinyuan〉Yumin.Gongliu population and Xinyuan population were the highest in genetic identity and the closest in genetic distance.Gene flow between the populations was 7.265 based on genetic differentiation coefficient(GST=0.064).The UPGMA cluster analysis indicated that the genetic relationships between the Gongliu and Xinyuan population were the closest,and the Yumin population were the farthest with the other three populations.The UPGMA cluster analysis indicated that the four geographical populations located in Gongliu,Xinyuan,Huocheng,and Yumin were relatively independent populations.Concurrently,there was also mild gene exchange between the populations.On the basis of the study of population genetic structure and the highest genetic diversity,Gongliu population should be given a high priority consideration in Malus sieversii population's in situ germplasm conservation.
文摘An investigation was conducted on distribution pattern, site condition and population structure of yew Taxus cuspidata Sieb. et Zucc. in Muling Forest Bureau of Heilongjiang Province, China in April, 2005. Results showed that yew is mainly distributed under the main storey of natural mixed forest of conifer and broadleaf, the soil moisture content of the yew site is high （40%-60%）, the pH value of soil is relatively lower （4.7-5.5）, and that the population structure of wild yew is not rational, belonging to the degeneration population, which is one of the reasons leading to the population decline. Although the site conditions of Muling area are suitable for the growth of wild yew, the population of wild yew shows a decline tendency, due to the fact that the middle-sized adult yew trees have been cut, young yews are often grazed by wildlife, and that the trunks of adult yew tend to be hollow.
文摘Nine Chinese yak breeds （Maiwa, Tianzhu White, Qinghai Plateau, Sibu, Zhongdian, Pali, Tibetan High Mountain, Jiulong, and Xinjiang） and Gayal were analyzed by means of 16 microsatellite markers to determine the level of genetic variation within populations, genetic relationship between populations, and population structure for each breed. A total of 206 microsatellite alleles were observed. Mean F-statistics （0.056） for 9 yak breeds indicated that 94.4% of the genetic variation was observed within yak breeds and 5.6% of the genetic variation existed amongst breeds. The Neighbor-Joining phylogenetic tree was constructed based on Nei＇s standard genetic distances and two clusters were obtained. The Gayal separated from the yaks far away and formed one cluster and 9 yak breeds were grouped together. The analysis of population structure for 9 yak breeds and the Gayal showed that they resulted in four clusters; one cluster includes yaks from Tibet Autonomous Region and Qinghai Province, one cluster combines Zhongdian, Maiwa, and Tianzhu White, and Jiulong and Xinjiang come into the third cluster. Pali was mainly in the first cluster （90%）, Jiulong was mainly in the second cluster （87.1%）, Zhongdian was primarily in the third cluster （83%）, and the other yak breeds were distributed in two to three clusters. The Gayal was positively left in the fourth cluster （99.3%）.
基金supported by National Natural Science Foundation of China(Grant Nos:31360200,31270742)the German Volkswagen Foundation within the framework of EcoCAR project(Az.:88497)
文摘Since 2000, the Chinese government has implemented emergency water diversion measures to restore the damaged riparian forest ecosystem with dominant tree species Euphrat poplar(Populus euphratica Oliv.)at the lower reaches of the Tarim River. In the present study, comparative analysis of variations in the vitality of P. euphratica trees were made using 2005 and 2010 data to illustrate the revitalization process of riparian forest. Poplar trees within 300 m of the riverbed were positively revitalized, while the vitality of trees farther than 300 m from the river decreased. Population structure was studied to demonstrate the development of poplar community. In the first belt, the class structure for the diameter at breast height(DBH) of P. euphratica fit a logistic model, and the 2nd, 3rd and 4th belt curve fittings were close to a Gaussian model; in other plots they were bimodal. Cluster analysis of the composition of the DBH class of poplar trees demonstrated that those within 16–36 cm DBH were the most abundant(58.49% of total) in study area, under 16 cm of DBH were second(31.36%), and trees >40 cm DBH were the least abundant(10.15%). More than 80% of the trees were young and medium-sized, which means that the poplar forest community in the vicinity of the lower Tarim River is at a stable developmental stage. The abundance of juvenile trees of P. euphratica in the first and second measuring belts was 12.13% in 2005 and increased to 25.52% in 2010, which means that the emergency water transfer had a positive impact on the generation of young P. euphratica trees in the vicinity of the river.
基金supported by the National Natural Science Foundation of China (30800700)the China Agriculture Research System
文摘To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity （GS） values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions （0.447）, while Australia accessions have the furthest distance （0.503）. A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.
基金This work was supported by the National Natural Science Foundation of China(No.30570171)100 Talents Program of Chinese Academy of Sciences(No.05045112)Wuhan Chenguang Project(No.20055003059-45).
文摘Three Epimedium species,E.pubescens Maxim.,E.sagittatum(Sieb.&Zucc.)Maxim.,and E.wushanense T.S.Ying,which are sympatrically distributed in the western Hubei Province,have been used in traditional Chinese medicine(TCM)for about 2,000 years.Genetic variability and population genetic structure of 11 natural populations of these Epimedium species were investigated using isoelectric focusing in thin-layer polyacrylamide slab gels.Of the 22 enzyme systems prescreened,six coding for 13 loci and 45 alleles were resolved,which were used for analyzing genetic diversity and population structure at both intraspecific and interspecific levels.The results showed that:l)high levels of genetic diversity were observed in all three species(A=2.6-3.2,P=69.2%-84.6%,Ho=0.274-0.377,HE=0.282-0.369),which were higher than that of other herbaceous and aulmal-pollinated species with similar life-history characteristics;2)there was significant deviation from Hardy-Weinberg Equilibrium,with one half of the loci showing heterozygote excess and the other homozygote excess,in all populations,suggesting the complicated breeding system of Epimedium species;3)the low level of intraspecific and interspecific genetic differentiation(GST=0.0246-0.0409 and 0.0495-0.1213,respectively)indicated a high level of gene flow among populations and close genetic relationship among the three species;and 4)UPGMA cluster analysis further showed that E.pubescens was more closely related to E.sagittatum than to E.wushanense,which was in good agreement with the morphological characters and the recent phylogenetic analysis of these species.On the basis of these results,it was concluded that the mixed breeding system,long-lived perennial life form,ancient evolutionary history,and seed dispersal by ants in Epimedium are responsible for the genetic variation and population structure of these species.
基金funded by the National Key Research and Development Plan(Grant No.2017YFD0101805)the National Science and Technology Foundation(Grant No.31501761)+2 种基金the National Modern Agricultural Industry Technology System Construction Special Fund Project(Grant No.CARS-23-A8)the Chinese Academy of Agricultural Sciences Science and Technology Innovation Project(Grant No.CAAS-ASTIP-IVF-CAAS)the State Key Laboratory of Vegetable Germplasm Innovation.
文摘To better understand the genetic diversity and population structure of broccoli cultivars planted in China,a total of 161 representative broccoli cultivars in the past 25 years were collected and analysed based on single nucleotide polymorphism(SNP)markers.Ten pairs of primers with good polymorphism and high resolution were screened from 315 pairs of SNP primers by 3 broccoli accessions(inbred lines)with different phenotypes and maturity.The 10 pairs of SNP primers were selected,producing 78 alleles.The diversity analysis indicated that the polymorphism information content(PIC)of SNP primer ranged from 0.64 to 0.90.The observed number of alleles(Na)was 2.00,the effective number of alleles(Ne)was 1.11–2.00,the Nei’s gene diversity(H)was 0.10–0.50,and Shannon information index(I)was 0.20–0.70 using PopGene32 software.The clustering results showed that the 161 broccoli cultivars could be divided into 4 major subgroups(A,B,C and D),foreign cultivars were all assigned to subgroup A,and domestic cultivars were assigned to 3 subgroups of B,C,and D.This study indicated that some domestic cultivars and foreign cultivars were similar in genetic background,but most domestic cultivars were still different from the Japanese cultivars.When K=2,the population structure result presented that 161 broccoli cultivars could be divided into 1 simple group(2 groups)and 1 mixed group.When Q≥0.6,143(88.82%)broccoli cultivars belonged to the simple groups.In simple groups 68(42.24%)broccoli cultivars of group 1 were derived from Japan,the United States,Switzerland,the Netherlands,China-Taiwan,and China-Mainland;75(46.58%)broccoli cultivars belonged to group 2;when Q<0.6,18(11.18%)broccoli cultivars belonged to the mixed groups.This study is helpful to understand the diversity and resolution of broccoli cultivars from worldwide,which is beneficial to plant breeding and materials innovation.And meanwhile,this result is also used for construction of broccoli fingerprint serving for cultivar identification.
基金National Key R&D Program of China (2019YFD1001301 and 2019YFD1001300)the earmarked fund for CARS-10Sweetpotato and the Hebei Key R&D Program, China (20326320D)。
文摘Sweetpotato, Ipomoea batatas(L.) Lam., is an important food crop worldwide. Large scale evaluation of sweetpotato germplasm for genetic diversity is necessary to determine the genetic relationships between them and effectively use them in the genetic improvement. In this study, the genetic diversity of 617 sweetpotato accessions, including 376landraces and 162 bred varieties from China and 79 introduced varieties from 11 other countries, was assessed using 30 simple sequence repeat(SSR) primer pairs with high polymorphism. Based on the population structure analysis,these sweetpotato accessions were divided into three groups, Group 1, Group 2 and Group 3, which included 228, 136and 253 accessions, respectively. Consistent results were obtained by phylogenic analysis and principal coordinate analysis(PCoA). Of the three groups, Group 2 showed the highest level of genetic diversity and its accessions were mainly distributed in low-latitude regions. The accessions from South China exhibited the highest level of genetic diversity, which supports the hypothesis that Fujian and Guangdong were the first regions where sweetpotato was introduced to China. Analysis of molecular variance(AMOVA) indicated significant genetic differentiations between the different groups, but low levels of genetic differentiation existed between the different origins and accession types.These results provide valuable information for the better utilization of these accessions in sweetpotato breeding.
基金Supported by the National Key Technology Research and Development Program of China(No.2011BAD13B08)the Central Nonprofit Basic Scientific Research Project for the Scientific Research Institutes of China(No.2011Z01)
文摘Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I （COl） gene. A total of 76 specimens were collected from three localities around the East （Qidong and Zhoushan） and South China Seas （Zhuhai）. Among these individuals, nine polymorphic sites were detected and 1 l distinct haplotypes were defined. High levels ofhaplotype diversity （h=0.759i0.035） and low levels of nucleotide diversity （re=0.001 98i0.003 26） were observed in these populations, Hierarchical analysis of molecular variance （AMOVA） indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant （~0~t=0.032 85, P〈0.01）. These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.
