<span style="font-family:Verdana;">This study was used</span><span style="font-family:Verdana;"> to</span><span style="font-family:;" "=""><...<span style="font-family:Verdana;">This study was used</span><span style="font-family:Verdana;"> to</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> lift nets and trap net fishing at intertidal zone of lagoon and estuarine regions of southern Taiwan. From July 2013 to July 2018, a total 420 specimens of </span><i><span style="font-family:Verdana;">Pisodonophis</span></i><span style="font-family:Verdana;"> were analyzed, the average total body length (TL) and average body weight (W) of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels are 68.4 ± 11.9 cm and 140.4 ± 86.1 g (N = 194), respectively. Typically, </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> eels are smaller (TL = 52.8 ± 9.2 cm) and lighter (W = 107.9 ± 73.7 g [N = 119]) than </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels. The natural logarithmic linear relationships between the TL and W of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> are respectively expressed as ln(W)</span><sub><span style="font-family:Verdana;">b</span></sub><span style="font-family:Verdana;"> = 2.4405 ln(TL) <span style="white-space:nowrap;">−</span> 5.4448 (R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.796, N = 194) and ln(W)</span><sub><span style="font-family:Verdana;">c</span></sub><span style="font-family:Verdana;"> = 3.2168 ln(TL) <span style="white-space:nowrap;">−</span> 8.2027, (</span><i><span style="font-family:Verdana;">R</span></i><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.934, N= 119). </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> typically preys on shrimp, crab, and fish;lab assessment revealed that the frequencies of occurrence of these foods in their guts were 49%, 21%, and 15%, respectively (N = 100). The main catch months of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> were during the rainy season, and that of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> were the winter season in Taiwan. The average W values of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> from Jhuoshuei and Puzih estuaries were 343.2 ± 218.8 g (N = 91) and 140.4 ± 86.1 g (N = 194), respectively. Furthermore, the results of the study revealed that the Puzih estuary is overfished. </span><span style="font-family:Verdana;">We suggest that fishery management units should develop some protection measures for the conservation of aquatic ecosystems in estuarine regions. For example, </span><span style="font-family:Verdana;">the </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> weighing less than 113 g will be released back to the estuary.</span></span>展开更多
The Fujian oyster(Crassostrea angulata) is an economically significant shellfish species distributed mainly along the Fujian coast, Southeast China. However, its genetic diversity and structure remain unclear. The mai...The Fujian oyster(Crassostrea angulata) is an economically significant shellfish species distributed mainly along the Fujian coast, Southeast China. However, its genetic diversity and structure remain unclear. The main distribution area of the C. angulata is located in Fujian, South China. In total, 420 C. angulata were collected from 14 natural habitats(populations) along the Fujian coast, and their genetic diversity and structure were analyzed in the mitochondrial COI and nuclear gene ITS2 sequences. Results reveal that all the 14 populations of C. angulata exhibited high levels of genetic diversity, with a total of 57(haplotype diversity: 0.811±0.016) and 124(haplotype diversity: 0.912±0.007) haplotypes revealed by COI and ITS2, respectively. Notably, significant intermediate level of genetic differentiations between the Ningde Zhujiang(ZJ) population(FS T by COI: 0.035–0.142, P<0.05;FS T by ITS2: 0.078–0.123, P<0.05) with other populations were observed for the first time, which is also supported by the results of molecular variance analysis(FC T by COI: 0.105, P<0.05;FC T by ITS2: 0.086, P<0.05) and the clustering of the ZJ population into distinct branches in the interpopulation genetic differentiation tree. Furthermore, the evolutionary tree and haplotype network analyses do not support the formation of a clear geographical genealogical structure among these 14 populations. In addition, the population dynamics analysis suggests that the C. angulata may have undergone expansion during the third ice age of the Pleistocene. These results provide a reference for the preservation and further genetic improvement of C. angulata.展开更多
Sechium edule(chayote)is an important vegetable crop belonging to the Cucurbitaceae family.To decipher the chayote genome,a highquality chromosome-level chayote genome was obtained by genome sequencing and bioinformat...Sechium edule(chayote)is an important vegetable crop belonging to the Cucurbitaceae family.To decipher the chayote genome,a highquality chromosome-level chayote genome was obtained by genome sequencing and bioinformatic analysis.The total length was612.91 Mb,and 25755 genes were detected in the chayote genome.The contig N50 was more than 20.01 Mb,and the scaffold N50 was over47.11 Mb.Of the genome,60.35%were composed of repetitive sequences,and 31.18%of genome sequences belonged to long-terminal repeats.A global alignment of homologous regions in chayote and other Cucurbitaceae plant genomes was constructed using grape as a reference.Based on this genome-wide and global alignment map,researchers can easily identify homologous collinear genes of the studied genomes in most Cucurbitaceae species.Twenty-five chayote accessions were divided into two subgroups based on phylogenetic tree,population structure analysis,and principal component analysis using genome re-sequencing data.The chayote genome,re-sequencing dataset,and comprehensive genomic analysis will accelerate comparative and functional genomic analysis of chayote and other Cucurbitaceae species in the future.展开更多
Understanding how species diverge and adapt is fundamental to unraveling biodiversity.While environmental impacts on species evolution are well-documented,the roles of intrinsic life-history traits remain underexplore...Understanding how species diverge and adapt is fundamental to unraveling biodiversity.While environmental impacts on species evolution are well-documented,the roles of intrinsic life-history traits remain underexplored.The Qinghai-Xizang Plateau,with its harsh conditions and unique biodiversity,offers a natural laboratory for such investigations.Here,we examine two sympatric small mammals—the solitary,low-dispersal plateau zokor(Eospalax baileyi)and the social,high-dispersal plateau pika(Ochotona curzoniae)—to elucidate how life-history traits shape population structures and adaptive strategies.Through whole-genome sequencing and cardiac-blood phenotype analyses,we reveal striking differences in their evolutionary trajectories.Despite enduring similar environmental pressures,plateau zokor populations exhibit pronounced genetic subdivisions,high inbreeding,and distinct local adaptations.In contrast,plateau pika populations display genetic panmixia,widespread diversity,and adaptive uniformity.Demographic inference highlights that plateau zokors experienced severe population bottlenecks and restricted gene flow during glacial periods,underscoring the impact of dispersal capacity on evolutionary outcomes.Our findings demonstrate that intrinsic biological traits,particularly dispersal ability,fundamentally influence genetic architecture,population connectivity,and local adaptation.This study not only provides empirical evidence of how life-history traits shape evolutionary dynamics but also offers a framework for integrating intrinsic and extrinsic factors in understanding biodiversity formation.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
Eighty-five pomegranate （Punica granatum L.） cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity b...Eighty-five pomegranate （Punica granatum L.） cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity by means of fluorescent-AFLP markers. The results indicated that 135-185 polymorphic loci were amplified by eight pairs of primers at species level. An average of 158.25 polymorphic loci was amplified for each primer combination. The polymorphism percentage ranged from 62.5% to 86.11%, and the average polymorphism percentage was 73.26%. This indicated that there was plentiful genetic diversity in pomegranate cultivars. The genetic diversity at the species level was higher than that at the population level. The order of the genetic diversity was Henan population 〉 Xinjiang population 〉 Shaanxi population 〉 Anhui population 〉 Shandong population 〉 Yunnan population. Variance analysis showed that there was significant difference between populations in genetic diversity. The genetic differentiation coefficient between populations （Gsr） was 0.2018, which indicated that gene differentiation was mainly within the population, and between populations, it accounted for 20.18% of the total variation. Gene flow （Nm） between the populations measured was 1.9027 based on the genetic differentiation coefficient between populations, indicating that there was mild gene flow between populations. The UPGMA cluster analysis showed that most accessions from the same population were clustered together, but there was partly gene exchange. All genetic parameters indicated that there was plentiful genetic diversity in pomegranate cultivars in China, of which Henan population was significantly higher than the other populations, and it had wide application foreground in pomegranate breeding in China.展开更多
In order to determine an appropriate sampling strategy for the effective conservation of wild soybean (Glycine soja Sieb. et Zucc.) in China, a natural population from Jiangwan Airport in Shanghai was studied for its ...In order to determine an appropriate sampling strategy for the effective conservation of wild soybean (Glycine soja Sieb. et Zucc.) in China, a natural population from Jiangwan Airport in Shanghai was studied for its genetic diversity through the inter-simple sequence repeat (ISSR) marker analysis of a sample set consisting of 100 randomly collected individuals. A relatively large genetic diversity was detected among the samples based on estimation of DNA products amplified from 15 selected ISSR primers, with the similarity coefficient varying from 0.17 to 0.89. The mean expected heterozygosity (He) was 0.171 4 per locus, and Shannon index (1) was 0.271 4. The Principal Coordinate Analysis (PCA) further indicated that genetic diversity of the Jiangwan wild soybean population was not evenly distributed, instead, was presented by a mosaic or clustered distribution pattern. Correlation study between genetic diversity and number of samples demonstrated that genetic diversity increased dramatically with the increase of number of samples within 40 individuals, but the increase became slow and rapidly reached a plateau when more than 40 individuals were included in the analysis. It is concluded that (i) a sample set of approximately 35-45 individuals should be included to represent possibly high genetic diversity when conservation of a wild soybean population ex situ is undertaken; and (ii) collection of wild soybean samples should be spread out as wide as possible within a population, and a certain distance should be kept as intervals among individuals for sampling.展开更多
The spatial distribution and population dynamics of Quercus liaotungensis Koidz., Fraxinus rhynchophylla Hance and Acer mono Maxim. were studied in three warm temperate deciduous forests in Dongling Mountain, Beijing....The spatial distribution and population dynamics of Quercus liaotungensis Koidz., Fraxinus rhynchophylla Hance and Acer mono Maxim. were studied in three warm temperate deciduous forests in Dongling Mountain, Beijing. Clumped distributions appeared in most seedlings (≤0.4 m), short saplings (0.4-1 m) and tall saplings (1-2 m). Random distributions appeared in adults of Q. liaotungensis in Plot 1, F. rhynchophylla in Plot 3. The LSD method was used to discern the differences of different aged population. The class distribution of Q. liaotungensis was nearly a reverse-J shape for Plot 1 and Plot 3, suggesting that the population regenerates continuously. The age-structures of F. rhynchophylla and A. mono in Plot 1 and the test results indicated that they would increase continuously. In Plot 2, the class distribution and the test results showed that all populations would not regenerate continuously.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
Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy can...Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy canopy. Method The effects of rice population structure traits under different N rates on rice canopy temperature, relative humidity （ RH）, light transmittance and sheath blight were studied by using Sunscan canopy analysis system and HOBO（ Pro Temp/RH IS logger）. Result The results showed that leaf area index, plant height and tiller number had significant effects on canopy cooling, RH enhancing and light reducing. Extremely significant multiple linear regression relationships existed among canopy day temperature, day RH, LAI and tiller number, and among light transmittance, tiller number and plant height. At flowering stage, per unit LAI could result in a day-maximum-temperature （Tmax） deceasing of 0.87℃ and a day-minimum-RH （RHmin） enhancing of 2.5% within canopy. Similarly, 100 plants per ms could respectively cause a Tmax deceasing of 1.23℃ and an RHmin enhancing of 3.3% in rice canopy. And per 10 cm plant height and 100 plants per m^2 could respectively reduce 9.3% and 7.8% of light in canopy. Conclusion Sheath blight disease index was significantly enhanced as the canopy day temperature decreased, day RH increased and light transmittance reduced. Bigger canopy from higher nitrogen level treatment leads to a more stable canopy microclimate with little changes in temperature and RH during day and night, which has the risk of worsening canopy health. Thus, moderately controlling the space development of canopy is the basis of constructing healthy canopy in rice.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
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
The spatial distribution of plant populations is an important feature of population structure and it de- termines the population＇s ecological preferences, biological characteristics and relationships with environment...The spatial distribution of plant populations is an important feature of population structure and it de- termines the population＇s ecological preferences, biological characteristics and relationships with environmental factors. The point pattern analysis method was adopted to study the distribution pattern of Picea schrenkiana indi- viduals of different size classes and the correlations between two size classes as well as the impact of topog- raphical attributes on the population distribution. With increasing diameter at breast height, the plant density of the P. schrenkiana population showed a declining trend. Old trees showed a random distribution at a small spatial scale （0-12 m）, whereas saplings, small trees and big trees all had an aggregated distribution at all scales. With the increase of tree age, the scales at which maximal aggregation occurred gradually increased and the aggregation strength decreased. At a small scale （0-16 m）, all size classes showed a negative correlation and the larger the difference between tree size, the more significant the negative correlation. The number of medium, big and old trees had a significantly positive correlation with elevations, whereas the number of saplings and small trees was not significantly correlated with elevations. The numbers of saplings, small and medium trees showed a significant positive correlation with slope gradient, whereas the number of big trees was not significantly correlated, and the number of old trees was negatively correlated with gradient. With the exception of old trees, saplings, small, me- dium and big trees showed negative correlations with convexity index. The study provides a theoretical basis for the conservation, rehabilitation and sustainable management of forest ecosystems in the Tianshan Mountains.展开更多
文摘<span style="font-family:Verdana;">This study was used</span><span style="font-family:Verdana;"> to</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> lift nets and trap net fishing at intertidal zone of lagoon and estuarine regions of southern Taiwan. From July 2013 to July 2018, a total 420 specimens of </span><i><span style="font-family:Verdana;">Pisodonophis</span></i><span style="font-family:Verdana;"> were analyzed, the average total body length (TL) and average body weight (W) of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels are 68.4 ± 11.9 cm and 140.4 ± 86.1 g (N = 194), respectively. Typically, </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> eels are smaller (TL = 52.8 ± 9.2 cm) and lighter (W = 107.9 ± 73.7 g [N = 119]) than </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> eels. The natural logarithmic linear relationships between the TL and W of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> are respectively expressed as ln(W)</span><sub><span style="font-family:Verdana;">b</span></sub><span style="font-family:Verdana;"> = 2.4405 ln(TL) <span style="white-space:nowrap;">−</span> 5.4448 (R</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.796, N = 194) and ln(W)</span><sub><span style="font-family:Verdana;">c</span></sub><span style="font-family:Verdana;"> = 3.2168 ln(TL) <span style="white-space:nowrap;">−</span> 8.2027, (</span><i><span style="font-family:Verdana;">R</span></i><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;"> = 0.934, N= 119). </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> typically preys on shrimp, crab, and fish;lab assessment revealed that the frequencies of occurrence of these foods in their guts were 49%, 21%, and 15%, respectively (N = 100). The main catch months of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> were during the rainy season, and that of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">cancrivorus</span></i><span style="font-family:Verdana;"> were the winter season in Taiwan. The average W values of </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> from Jhuoshuei and Puzih estuaries were 343.2 ± 218.8 g (N = 91) and 140.4 ± 86.1 g (N = 194), respectively. Furthermore, the results of the study revealed that the Puzih estuary is overfished. </span><span style="font-family:Verdana;">We suggest that fishery management units should develop some protection measures for the conservation of aquatic ecosystems in estuarine regions. For example, </span><span style="font-family:Verdana;">the </span><i><span style="font-family:Verdana;">P</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">boro</span></i><span style="font-family:Verdana;"> weighing less than 113 g will be released back to the estuary.</span></span>
基金Supported by the National Natural Science Foundation of China(No.32172979)the Natural Science Foundation of Fujian Province(No.2021J05159)the 2023 Special Program for Promoting High-Quality Development of Marine and Fishery Industry in Fujian Province(No.PJHYF-L-2023-2)。
文摘The Fujian oyster(Crassostrea angulata) is an economically significant shellfish species distributed mainly along the Fujian coast, Southeast China. However, its genetic diversity and structure remain unclear. The main distribution area of the C. angulata is located in Fujian, South China. In total, 420 C. angulata were collected from 14 natural habitats(populations) along the Fujian coast, and their genetic diversity and structure were analyzed in the mitochondrial COI and nuclear gene ITS2 sequences. Results reveal that all the 14 populations of C. angulata exhibited high levels of genetic diversity, with a total of 57(haplotype diversity: 0.811±0.016) and 124(haplotype diversity: 0.912±0.007) haplotypes revealed by COI and ITS2, respectively. Notably, significant intermediate level of genetic differentiations between the Ningde Zhujiang(ZJ) population(FS T by COI: 0.035–0.142, P<0.05;FS T by ITS2: 0.078–0.123, P<0.05) with other populations were observed for the first time, which is also supported by the results of molecular variance analysis(FC T by COI: 0.105, P<0.05;FC T by ITS2: 0.086, P<0.05) and the clustering of the ZJ population into distinct branches in the interpopulation genetic differentiation tree. Furthermore, the evolutionary tree and haplotype network analyses do not support the formation of a clear geographical genealogical structure among these 14 populations. In addition, the population dynamics analysis suggests that the C. angulata may have undergone expansion during the third ice age of the Pleistocene. These results provide a reference for the preservation and further genetic improvement of C. angulata.
基金supported by the National Natural Science Foundation of China Project(Grant No.32260097)the National Guidance Foundation for Local Science and Technology Development of China(Grant No.[2023]009)the Natural Science Foundation for Distinguished Young Scholars of Hebei(Grant No.C2022209010)。
文摘Sechium edule(chayote)is an important vegetable crop belonging to the Cucurbitaceae family.To decipher the chayote genome,a highquality chromosome-level chayote genome was obtained by genome sequencing and bioinformatic analysis.The total length was612.91 Mb,and 25755 genes were detected in the chayote genome.The contig N50 was more than 20.01 Mb,and the scaffold N50 was over47.11 Mb.Of the genome,60.35%were composed of repetitive sequences,and 31.18%of genome sequences belonged to long-terminal repeats.A global alignment of homologous regions in chayote and other Cucurbitaceae plant genomes was constructed using grape as a reference.Based on this genome-wide and global alignment map,researchers can easily identify homologous collinear genes of the studied genomes in most Cucurbitaceae species.Twenty-five chayote accessions were divided into two subgroups based on phylogenetic tree,population structure analysis,and principal component analysis using genome re-sequencing data.The chayote genome,re-sequencing dataset,and comprehensive genomic analysis will accelerate comparative and functional genomic analysis of chayote and other Cucurbitaceae species in the future.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(2019QZKK05010900 and 2019QZKK05010405)the National Natural Science Foundation of China(32100339 and 32200350)+3 种基金Yunnan Revitalization Talent Support Program Top team(202405AS350022)supported by the Youth Innovation Promotion Association,Chinese Academy of Sciencessupported by Yunnan Fundamental Research Projects(202201AU070208)supported by Yunnan Revitalization Talent Support Program Yunling Scholar Project(XML)。
文摘Understanding how species diverge and adapt is fundamental to unraveling biodiversity.While environmental impacts on species evolution are well-documented,the roles of intrinsic life-history traits remain underexplored.The Qinghai-Xizang Plateau,with its harsh conditions and unique biodiversity,offers a natural laboratory for such investigations.Here,we examine two sympatric small mammals—the solitary,low-dispersal plateau zokor(Eospalax baileyi)and the social,high-dispersal plateau pika(Ochotona curzoniae)—to elucidate how life-history traits shape population structures and adaptive strategies.Through whole-genome sequencing and cardiac-blood phenotype analyses,we reveal striking differences in their evolutionary trajectories.Despite enduring similar environmental pressures,plateau zokor populations exhibit pronounced genetic subdivisions,high inbreeding,and distinct local adaptations.In contrast,plateau pika populations display genetic panmixia,widespread diversity,and adaptive uniformity.Demographic inference highlights that plateau zokors experienced severe population bottlenecks and restricted gene flow during glacial periods,underscoring the impact of dispersal capacity on evolutionary outcomes.Our findings demonstrate that intrinsic biological traits,particularly dispersal ability,fundamentally influence genetic architecture,population connectivity,and local adaptation.This study not only provides empirical evidence of how life-history traits shape evolutionary dynamics but also offers a framework for integrating intrinsic and extrinsic factors in understanding biodiversity formation.
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2006 Shandong Provincial Science and Technology Development Plans (No. 2006GG2209009)Research Funds for Junior Scientist of Shandong Academy of Agricultural Sciences (No. 2005YQ012).
文摘Eighty-five pomegranate （Punica granatum L.） cultivars from six geographical populations located at Shandong, Anhui, Shaanxi, Henan, Yunnan, and Xinjiang Provinces were studied for its population genetic diversity by means of fluorescent-AFLP markers. The results indicated that 135-185 polymorphic loci were amplified by eight pairs of primers at species level. An average of 158.25 polymorphic loci was amplified for each primer combination. The polymorphism percentage ranged from 62.5% to 86.11%, and the average polymorphism percentage was 73.26%. This indicated that there was plentiful genetic diversity in pomegranate cultivars. The genetic diversity at the species level was higher than that at the population level. The order of the genetic diversity was Henan population 〉 Xinjiang population 〉 Shaanxi population 〉 Anhui population 〉 Shandong population 〉 Yunnan population. Variance analysis showed that there was significant difference between populations in genetic diversity. The genetic differentiation coefficient between populations （Gsr） was 0.2018, which indicated that gene differentiation was mainly within the population, and between populations, it accounted for 20.18% of the total variation. Gene flow （Nm） between the populations measured was 1.9027 based on the genetic differentiation coefficient between populations, indicating that there was mild gene flow between populations. The UPGMA cluster analysis showed that most accessions from the same population were clustered together, but there was partly gene exchange. All genetic parameters indicated that there was plentiful genetic diversity in pomegranate cultivars in China, of which Henan population was significantly higher than the other populations, and it had wide application foreground in pomegranate breeding in China.
文摘In order to determine an appropriate sampling strategy for the effective conservation of wild soybean (Glycine soja Sieb. et Zucc.) in China, a natural population from Jiangwan Airport in Shanghai was studied for its genetic diversity through the inter-simple sequence repeat (ISSR) marker analysis of a sample set consisting of 100 randomly collected individuals. A relatively large genetic diversity was detected among the samples based on estimation of DNA products amplified from 15 selected ISSR primers, with the similarity coefficient varying from 0.17 to 0.89. The mean expected heterozygosity (He) was 0.171 4 per locus, and Shannon index (1) was 0.271 4. The Principal Coordinate Analysis (PCA) further indicated that genetic diversity of the Jiangwan wild soybean population was not evenly distributed, instead, was presented by a mosaic or clustered distribution pattern. Correlation study between genetic diversity and number of samples demonstrated that genetic diversity increased dramatically with the increase of number of samples within 40 individuals, but the increase became slow and rapidly reached a plateau when more than 40 individuals were included in the analysis. It is concluded that (i) a sample set of approximately 35-45 individuals should be included to represent possibly high genetic diversity when conservation of a wild soybean population ex situ is undertaken; and (ii) collection of wild soybean samples should be spread out as wide as possible within a population, and a certain distance should be kept as intervals among individuals for sampling.
文摘The spatial distribution and population dynamics of Quercus liaotungensis Koidz., Fraxinus rhynchophylla Hance and Acer mono Maxim. were studied in three warm temperate deciduous forests in Dongling Mountain, Beijing. Clumped distributions appeared in most seedlings (≤0.4 m), short saplings (0.4-1 m) and tall saplings (1-2 m). Random distributions appeared in adults of Q. liaotungensis in Plot 1, F. rhynchophylla in Plot 3. The LSD method was used to discern the differences of different aged population. The class distribution of Q. liaotungensis was nearly a reverse-J shape for Plot 1 and Plot 3, suggesting that the population regenerates continuously. The age-structures of F. rhynchophylla and A. mono in Plot 1 and the test results indicated that they would increase continuously. In Plot 2, the class distribution and the test results showed that all populations would not regenerate continuously.
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 Oversea Project of National Natural and Science Foundationof China(30528005)RTOP Project of International RiceResearch Institute(IRRI)+1 种基金Grain High-yield Project of China(2004BA520A12)And 948 Introduction Project of the Ministry ofAgriculture(2003-Z53)~~
文摘Objective The aim was to elucidate the effects of N rates on rice canopy microclimate and community health so as to provide a sci- entific basis for studying the production potential in irrigated rice with healthy canopy. Method The effects of rice population structure traits under different N rates on rice canopy temperature, relative humidity （ RH）, light transmittance and sheath blight were studied by using Sunscan canopy analysis system and HOBO（ Pro Temp/RH IS logger）. Result The results showed that leaf area index, plant height and tiller number had significant effects on canopy cooling, RH enhancing and light reducing. Extremely significant multiple linear regression relationships existed among canopy day temperature, day RH, LAI and tiller number, and among light transmittance, tiller number and plant height. At flowering stage, per unit LAI could result in a day-maximum-temperature （Tmax） deceasing of 0.87℃ and a day-minimum-RH （RHmin） enhancing of 2.5% within canopy. Similarly, 100 plants per ms could respectively cause a Tmax deceasing of 1.23℃ and an RHmin enhancing of 3.3% in rice canopy. And per 10 cm plant height and 100 plants per m^2 could respectively reduce 9.3% and 7.8% of light in canopy. Conclusion Sheath blight disease index was significantly enhanced as the canopy day temperature decreased, day RH increased and light transmittance reduced. Bigger canopy from higher nitrogen level treatment leads to a more stable canopy microclimate with little changes in temperature and RH during day and night, which has the risk of worsening canopy health. Thus, moderately controlling the space development of canopy is the basis of constructing healthy canopy in rice.
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.
基金funded by the 12th Five-year Science and Technology Support Program(2011BAD38B0505)the Forestry Industry Research Special Funds for Public Welfare Projects (200804022C)the CFERN & GENE Award Funds on Ecological Papers
文摘The spatial distribution of plant populations is an important feature of population structure and it de- termines the population＇s ecological preferences, biological characteristics and relationships with environmental factors. The point pattern analysis method was adopted to study the distribution pattern of Picea schrenkiana indi- viduals of different size classes and the correlations between two size classes as well as the impact of topog- raphical attributes on the population distribution. With increasing diameter at breast height, the plant density of the P. schrenkiana population showed a declining trend. Old trees showed a random distribution at a small spatial scale （0-12 m）, whereas saplings, small trees and big trees all had an aggregated distribution at all scales. With the increase of tree age, the scales at which maximal aggregation occurred gradually increased and the aggregation strength decreased. At a small scale （0-16 m）, all size classes showed a negative correlation and the larger the difference between tree size, the more significant the negative correlation. The number of medium, big and old trees had a significantly positive correlation with elevations, whereas the number of saplings and small trees was not significantly correlated with elevations. The numbers of saplings, small and medium trees showed a significant positive correlation with slope gradient, whereas the number of big trees was not significantly correlated, and the number of old trees was negatively correlated with gradient. With the exception of old trees, saplings, small, me- dium and big trees showed negative correlations with convexity index. The study provides a theoretical basis for the conservation, rehabilitation and sustainable management of forest ecosystems in the Tianshan Mountains.
