Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatom...Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously dif-ference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude.展开更多
Microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this ...Microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this study showed high polymorphism in both hatchery and wild populations, as observed in an average number of allele per locus (19.1-29.9) and average expected heterozygosity (0.916-0.958). No significant difference in average allelic richness or expected heterozygosity was observed between Chinese hatchery populations and Japanese wild populations. Pairwise Fsr values and heterogeneity tests of allele frequencies showed significant genetic differentiation between all populations. According to the neighbor-joining tree constructed on the basis of the Dc distance, the seven populations fell into three groups showing a clear division between hatchery and wild populations, and between the northern and southern hatchery populations. Assignment tests correctry assigned high percentages (97%-100%) of individuals to their original populations and demonstrated the feasibility of microsatellite analysis for discrimination between populations. The information obtained in this study is useful for designing suitable management guidelines and selective breeding programs for the Pacific oyster in China.展开更多
[Objective] This study aimed to investigate the genetic variation of g E gene of an epidemic pseudorabies virus(PRV) strain and its pathogenicity to piglets. [Method] By serial passage in Vero cells, a PRV strain wa...[Objective] This study aimed to investigate the genetic variation of g E gene of an epidemic pseudorabies virus(PRV) strain and its pathogenicity to piglets. [Method] By serial passage in Vero cells, a PRV strain was isolated from the brain tissues of stillborn fetuses delivered by sows with suspected PRV infection and preliminarily identified by PCR. g E gene of the isolated PRV strain was amplified and sequenced for phylogenetic analysis. In addition, the pathogenicity of the isolated PRV strain to 6-week-old piglets was evaluated. [Result] A PRV strain was successfully isolated and named PRV N5 B strain, which could proliferate in Vero cells and TCID50 of the 15 thgeneration virus liquid reached 10^7.125/0.1 ml. Specific bands could be amplified by PCR. g E gene in the isolated PRV strain was 1 740 bp in length. A phylogenetic tree was constructed based on full-length g E sequences, which showed that PRV N5 B strain and PRV strains isolated since 2012 were clustered into the same independent category and shared 99.7%-100% homology of nucleotide sequences. Compared with related sequences published previously, there were insertions of three consecutive bases at two loci. Animal experiments showed that intranasal inoculation of 6-week-old piglets with 2 ml of PRV N5 B strain(10^6/0.1 ml) led to a mortality rate of 100%. [Conclusion] In this study,genetic variability of g E gene in PRV N5 B isolate and its pathogenicity to piglets were analyzed, which provided a theoretical basis for the development of new vaccines to prevent and control porcine pseudorabies.展开更多
The somatic hybrid KT1 was previously obtained from protoplast fusion between sweetpotato (Ipomoea batatas (L.) Lam.) cv. Kokei No. 14 and its wild relative I. triloba L. However, its genetic and epigenetic variat...The somatic hybrid KT1 was previously obtained from protoplast fusion between sweetpotato (Ipomoea batatas (L.) Lam.) cv. Kokei No. 14 and its wild relative I. triloba L. However, its genetic and epigenetic variations have not been investigated. This study showed that KT1 exhibited significantly higher drought tolerance compared to the cultivated parent Kokei No. 14. The content of proline and activities of superoxide dismutase (SOD) and photosynthesis were significantly increased, while malonaldehyde (MDA) content was significantly decreased compared to Kokei No. 14 under drought stress. KT1 also showed higher expression level of well-known drought stress-responsive genes compared to Kokei No. 14 under drought stress. Amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP) analyses indicated that KT1 had AFLP and MSAP band patterns consisting of both parent specific bands and changed bands. Fur- ther analysis demonstrated that in KT1. the proportions of Kokei No. 14 specific genome components and methylation sites were much greater than those of I. triloba. KT1 had the same chloroplast and mitochondrial genomes as Kokei No. 14. These results will aid in developing the useful genes ofI. triloba and understanding the evolution and phylogeny of the cultivated sweetpotato.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
[Objective] This study aimed to investigate the prevalence and variation of porcine kobuvirus (PKV) in suckling piglets in China. [Method] In 2013-2014, 224 feces samples from suckling piglets with diarrhea in 27 pi...[Objective] This study aimed to investigate the prevalence and variation of porcine kobuvirus (PKV) in suckling piglets in China. [Method] In 2013-2014, 224 feces samples from suckling piglets with diarrhea in 27 pig farms of five provinces in China were collected to detect 3D genes of PKV with RT-PCR method; the sequences and genetic variation of 29 PKV 3D genes were analyzed. [Result] Total positive rate of PKV in feces samples from suckling piglets with diarrhea was 65.18% (146/224); total positive rate of PKV in pig farms was 85,2% (23/27); nucleotide sequences and the deduced amino acid sequences of 29 PKV 3D genes shared 87.0%-100% and 92.7%-100% homologies with six PKV-related 3D sequences, respectively. [Conclusion] PKV infection is prevalent in suckling piglets in China; PKV 3D genes exhibit high diversity.展开更多
[Objective] A total of 260 swine samples of dead or sick pigs collected from 7 provinces (municipalities) Jiangsu, Anhui, Shanghai, Shandong, Zhejiang, Fujian and Jiangxi of China during 2008-2010 were detected for ...[Objective] A total of 260 swine samples of dead or sick pigs collected from 7 provinces (municipalities) Jiangsu, Anhui, Shanghai, Shandong, Zhejiang, Fujian and Jiangxi of China during 2008-2010 were detected for porcine reproductive and respiratory syndrome virus (PRRSV). And the ORF5 genes of some isolates were amplified and sequenced for understanding the molecule epidemiology and the genetic evolution of PRRSV in East China. [Method] Using RT-PCR method, PRRSV was detected by RT-PCR from samples. The complete ORF5 genes of 36 PRRSV positive samples was amplified, sequenced and analyzed with other 15 strains available on GenBank. [Result] PRRSV was detected in 118/260 of the clinical samples, with a positive rate was 45.4%. Sequence analysis showed that the 36 isolates of this study belonged to the North American-type PRRSV strains and were closely related to the highly pathogenic PRRSV (HP-PRRSV) with 94.6%-100% amino acid sequence identities. The sequence analysis combined with the phylogenetic analysis indicated that all these North American-type PRRSV strains in East China were further divided into five subgenotypes, subgenotype Ⅲ showed closer identity with HPPRRSV; almost all subgenotypes were found to be variable in the primary neutralizing epitope; subgenotypes Ⅲ and IV had more glycosylation sites than others. Although these 36 isolates were collected from different provinces in East China, there were no obvious relations between the distribution of PRRSV and the region. [Conclusion] The PRRSV infection was widespread and HP-PRRSV was the popular strain in East China during 2008-2010. However some different genetic characteristics appeared in the genomes, the genetic evolution was relatively stable. There exists a cross-cutting phenomenon on the genetic relationship of PRRSV isolates obtained from different provinces. Subgenotypes IV and V only appeared in some provinces, but the distribution of PRRSV did not show apparent geographical characteristics.展开更多
[Objective] This study aimed to investigate the genetic variation of porcine circovirus type 2 (PCV2) in China. [Method] The strain was isolated from infected samples by cel passage and preliminarily identified by P...[Objective] This study aimed to investigate the genetic variation of porcine circovirus type 2 (PCV2) in China. [Method] The strain was isolated from infected samples by cel passage and preliminarily identified by PCR and IFA. Ful-length genome of the isolated strain was obtained by specific amplification for homology and phylogenetic analysis. [Result] A PCV2 strain was successful y isolated and named 201105ZJ, which could proliferate in PK15 cel lines. Specific fragments could be amplified by specific PCR assay. According to results of IFA assay, specif-ic immunofluorescence was observed; the TCID50 was low (102.67); the ful-length genome sequence of the isolated strain was 1 768 bp, sharing 94.1%-96.8% ho-mology with 13 reference strains; to be specific, the isolated strain exhibited the highest homology of 96.8% with AF055392PCV2a; the isolated strain 201105ZJ and reference strain AF055392 belonged to genotype PCV2a, exhibiting a distant genetic relationship with genotype PCV2c. [Conclusion] Characteristics of genetic variation of PCV2 isolate 201105ZJ provided theoretical basis for vaccine development, investi-gation of PCV2 pathogenesis, and prevention and control of porcine circovirus-as-sociated diseases (PCVAD) in East China.展开更多
For the population genetics analysis of the naturally grown brown seaweed Laminaria japonica (Laminariales,Phaeophyta) sampled from Dalian,Yantai,Weihai,Rongcheng and Qingdao in China,ten primers were employed to pr...For the population genetics analysis of the naturally grown brown seaweed Laminaria japonica (Laminariales,Phaeophyta) sampled from Dalian,Yantai,Weihai,Rongcheng and Qingdao in China,ten primers were employed to produce 88 bands as revealed by randomly amplified polymorphic DNA (RAPD) markers,and all these bands were polymorphic.According to these band patterns,there were 94 distinct phenotypes occurred in 100 samples indicating the high heterozygosity of this kelp.Dalian population samples showed the highest percentage of polymorphism (71.67%),and also the higher diversity estimated on the basis of the Shannon’s index (8.498),suggesting that this population could be chosen as the best resource for genetic breeding.The highest diversity of Yantai population possibly resulted from the introduction of L.longissima used for interspecific cross breeding with L.japonica cultivated in China.From Dalian southwards to Qingdao,the genetic variation of the five populations became less with a decrease in latitude,possibly due to the natural selection especially of high temperature.The genetic distance (Φ ST values) of the five populations was a little significantly correlated with the geographical distance (r=0.496) at P =0.05 by Mantel’s test.Weihai,Rongcheng and Yantai populations were closely grouped genetically together by Neighbor-joining cluster analysis probably in that the dispersal of the kelp by propagules more easily occurring in the range of relatively short distance.The analysis of molecular variance (AMOVA) also demonstrated that the relatively higher variation occurred among populations (71.49%) at an extremely significant level (P 0.000 1).All these evidence showed that there was a relatively distinct genetic differentiation among the sampled kelp populations,and L.japonica grown in China was also rather heterozygous in heredity.展开更多
It was helpful for the wheat improvement to evaluate the genetic resources of Triticum turgidum L. ssp. turgidum landraces. In this study, 68 turgidum landraces accessions, belonging to four geographic populations in ...It was helpful for the wheat improvement to evaluate the genetic resources of Triticum turgidum L. ssp. turgidum landraces. In this study, 68 turgidum landraces accessions, belonging to four geographic populations in China, were investigated by using EST-SSR markers. A total of 63 alleles were detected on 22 EST-SSR loci, and the number of alleles on each locus ranged from 1 to 5, with an average of 2.9. The results of the analysis of molecular variance (AMOVA) indicated that 92.5% of the total variations was attributed to the genetic variations within population, whereas only 7.5% variations among populations. Although the four populations had similar genetic diversity parameters, Sichuan population was yet distinguished from other populations when comparing the population samples in pairs. Significant correlations were detected by the statistic analysis among six genetic diversity parameters among each other. The selection difference between heterozygosty and homozygosty was also observed among different EST-SSR locus. The genetic similarity (GS) ranged from 0.18 to 0.98, with the mean of 0.72, and all accessions could be clustered into 7 groups. The dendrogram suggested that the genetic relationships among turgidum accessions evaluated by EST-SSR markers were unrelated to their geographic distributions. These results implied that turgidum landraces from China had the unique characters of genetic diversity.展开更多
Inter Simple Sequence Repeat (ISSR) was used to detect genetic variation among nine provenances, including 135 individuals. A total of 108 loci were amplified using 10 random primers. The differentiation of the perc...Inter Simple Sequence Repeat (ISSR) was used to detect genetic variation among nine provenances, including 135 individuals. A total of 108 loci were amplified using 10 random primers. The differentiation of the percentage of polymorphic bands (PPB) among different provenances was evident, ranging from 27% to 54%. of which Honghuaerji provenance had the highest PPB and Kalunshan provenance had the lowest PPB. Shannon's Information index (1) at species level was 0.1581 and Nei's gene diversity (h) was 0.2393. Coefficient of gene differentiation (Gsr) calculated by Popgene was 0.3965, these results indicated that majority of genetic variation (60.35%) was found within provenances. According to dendrogram among pinus sylvestriv provenances, nine provenances were divided into two provenance areas. namely Daxing'an and Xiaoxing'an Mountains provenance area and Hulunbeier provenance area.展开更多
A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate (A/Chicken/ Hebei/WD/98, abbreviated as WD98) by comparing with other reference strains. I...A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate (A/Chicken/ Hebei/WD/98, abbreviated as WD98) by comparing with other reference strains. I-Method3 Eight complete genes were amplified by RT-PCR and sequenced. The homology and genetic evolution relationship were analyzed between these sequences and that of the seven reference strains. [Result] The whole genomic sequence of WD98 strain was 91.1% -95.8% homologous to that of seven reference strains tested. This isolate shared the highest homology (95.8%) to D/HK/Y280/97 and the lowest homology (91.1% ) to C/Pak/2/99. The HA cleavage site of the WD98 strain was R-S-S-R G, and the 226th amino acid at receptor-binding site was Gin. [ Condmion] WD98 strain belongs to mildly pathogenic avian in- fluenza virus and may not infect human. The genetic relationship is the closest between A/Chicken/Hebei/wD/98 and A/duck/HongKong/Y280/ 97, both of which belong to the sub-line of A/Chicken/Beijing/1/94 in Eurasian line. And A/Chicken/Hebei/WD/98 and A/Chicken/Beijing/1/94 are genetically distant within the same sub-line.展开更多
AIM:To explore the association between mothers against decapentaplegic homolog 4 (SMAD4) gene polymorphisms and gastric cancer risk.METHODS:Five tagging single nucleotide polymor-phisms (tSNPs) in the SMAD4 gene were ...AIM:To explore the association between mothers against decapentaplegic homolog 4 (SMAD4) gene polymorphisms and gastric cancer risk.METHODS:Five tagging single nucleotide polymor-phisms (tSNPs) in the SMAD4 gene were selected and genotyped in 322 gastric cancer cases and 351 cancerfree controls in a Chinese population by using the polymerase chain reactionrestriction fragment length polymorphism method.Immunohistochemistry was used to examine SMAD4 protein expression in 10 normal gastric tissues adjacent to tumors.RESULTS:In the single-locus analysis,two significantly decreased risk polymorphisms for gastric cancer were observed:the SNP3 rs17663887 TC genotype (adjusted odds ratio=0.38,95% confidence interval:0.21-0.71),compared with the wild-type TT genotype and the SNP5 rs12456284 GG genotype (0.31,0.16-0.60),and with the wild-type AA genotype.In the combined analyses of these two tSNPs,the combined genotypes with 2-3 protective alleles (SNP3 C and SNP5 G allele) had a significantly decreased risk of gastric cancer (0.28,0.16-0.49) than those with 0-1 protective allele.Furthermore,individuals with 0-1 protective allele had significantly decreased SMAD4 protein expression levels in the norma tissues adjacent to tumors than those with 2-3 protective alleles (P=0.025).CONCLUSION:These results suggest that genetic variants in the SMAD4 gene play a protective role in gastric cancer in a Chinese population.展开更多
To investigate the genetic structures and differentiation of different wild populations of white croaker (Pennahia argentara), horizontal starch gel electrophoresis was performed on 133 individuals collected from fi...To investigate the genetic structures and differentiation of different wild populations of white croaker (Pennahia argentara), horizontal starch gel electrophoresis was performed on 133 individuals collected from five different locations in China and Japan. The eleven enzyme systems revealed 15 loci, of which eleven were polymorphic. The percentage ofpolymorphic loci of white croaker populations varied from 6.67% to 53.3.3%; the mean observed and expected heterozygosity ranged from 0.0033 to 0.0133 and 0.0032 to 0.0191, respectively. The expected heterozygosity revealed a low genetic variability for white croaker in comparison with other marine fishes. The genetic distances between populations ranged from 0.00005 to 0.00026. A weak differentiation was observed within each clade and between clades; and no significant differences in gene frequencies among populations were observed in white croaker. Among the five populations, three Chinese populations showed more genetic diversity than that in Japanese populations.展开更多
Population genetics of the left-eyed flounder, Paralichthys olivaceus, including natural and cultured stocks distributed in the coastal waters near Qingdao of eastern maritime China, was analyzed in allozyme and RAPD....Population genetics of the left-eyed flounder, Paralichthys olivaceus, including natural and cultured stocks distributed in the coastal waters near Qingdao of eastern maritime China, was analyzed in allozyme and RAPD. The results showed that among total 29 gene loci of 15 isozymes, 9 and 7 were po- lymorphic in natural and cultured stocks, respectively. The status of genetic diversity in P. olivaceus is low in terms of polymorphic loci in chi-square test and genetic departure index of Hardy-Weinberg equi- librium. More alleles in IDHP, CAT, GDH and Ldh-C allozymes were found in the fish, which could be used as markers in assortive breeding and distinguishing stock, population or species evolution. Total 88 and 86 RAPD bands ranging from 200 to 2 500 bp were recognized individually in average of 7.8–8.0 bands per primer. The genetic diversity in cultured stock is lower than that in natural ones showing an ob- viously decreasing genetic divergence. Therefore, effective countermeasures must be taken to protect ge- netic resources of marine cultured fishes. The 2 markers have their own pros and cons. Combining the 2 markers to investigate the genetic variation of populations is suggested. The results provide basic data of this flounder and they are useful for studying genetic improvement and genetic resources of the fish.展开更多
Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the lev...Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.展开更多
Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were exam...Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were examined for forty-nine Chinese mitten crabs and thirty-eight Hepu mitten crabs. Nine loci, AAT-1 *, AAT-2 *, G3PDH *, GPI *, IDHP-1 *, IDHP-2 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Chinese mitten crab, and seven, AAT-1 *, AAT-2 *, GPI *, IDHP-1 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Hepu mitten crab. The proportion of polymorphic loci and the expected heterozygosity are 0.562 5 and 0.080 3 for Chinese mitten crab, and 0.437 5 and 0.075 4 for Hepu mitten crab. The Nei’s genetic distance between two species is 0.002 4.展开更多
DNA methylation plays an important role in plant growth and development,and in regulating the activity of transposable elements(TEs).Research on DNA methylation-related(DMR)genes has been reported in Arabidopsis,but l...DNA methylation plays an important role in plant growth and development,and in regulating the activity of transposable elements(TEs).Research on DNA methylation-related(DMR)genes has been reported in Arabidopsis,but little research on DMR genes has been reported in Brassica rapa and Brassica oleracea,the genomes of which exhibit significant differences in TE content.In this study,we identified 78 and 77 DMR genes in Brassica rapa and Brassica oleracea,respectively.Detailed analysis revealed that the numbers of DMR genes in different DMR pathways varied in B.rapa and B.oleracea.The evolutionary selection pressure of DMR genes in B.rapa and B.oleracea was compared,and the DMR genes showed differential evolution between these two species.The nucleotide diversity(π)and selective sweep(Tajima’s D)revealed footprints of selection in the B.rapa and B.oleracea populations.Transcriptome analysis showed that most DMR genes exhibited similar expression characteristics in B.rapa and B.oleracea.This study dissects the evolutionary differences and genetic variations of the DMR genes in B.rapa and B.oleracea,and will provide valuable resources for future research on the divergent evolution of DNA methylation between B.rapa and B.oleracea.展开更多
To improve wood quality for pulpwood industries, it is important to examine not only wood density but also its components, especially tracheid characteristics. We studied genetic variations in the following tracheid t...To improve wood quality for pulpwood industries, it is important to examine not only wood density but also its components, especially tracheid characteristics. We studied genetic variations in the following tracheid traits by earlywood (EW) and latewood (LW): tracheid length (TL), double wall thickness (WT), radial lumen diameter (R_D1), tangential lumen diameter (T_D1), radial central diameter (R_D2), and tangential central diameter (T_D2). We also studied the relationship with the following growth traits: diameter at breast height (DBH), height (H), crown breadth south-north axis (NSC), crown breadth east-west axis (EWC), ring width (RW), latewood percentage (LWP), and wood density (WD). All sample materials were collected from a 33-year old clonal seed orchard of Pinus tabuliformis Carr. Genetic variation among clones was moderate for all tracheid traits, 9.49-26.03%. Clones significantly affected WT, R_D1, R_D2, T_D1, T_D2, and the two ratios WT/R_D1 and TL/T_D2 in EW but had no effects in LW. Clones significantly affected TL in LW but had no effects in EW. H2/C was higher in LW (0.50) than in EW (0.20) for TL, while H 2/C was higher in EW (0.27-0.46) for other tracheid traits and the two ratios (TL/T_D2 and WT/R_D1) than in EW (0.06-0.22). WD and TL were significantly positively correlated, but WT and TL were negatively correlated both at individual and clone levels; all tracheid diameters and the four ratio values (EW_WT/ R_D1, LW WT/R_D1, EW_TL/T_D2 and LW_TL/ T_D2), were strongly positively correlated with DBH, H, NSC, WEC and RW, and strongly negatively correlated with WD both at individual and clone levels. The most important variables for predicting WD were LW_TL, EW_WT and R_D1 in both EW and LW (r2= 0.22). Selecting the top 10% of the clones by DBH would improve DBH growth by 12.19% (wood density was reduced by 0.14%) and produced similar responses between EW and LW for all tracheid traits: a reduction of 0.94 and 3.69% in tracheid length and increases in tracheid diameters (from 0.36 to 5.24%) and double wall thickness (0.07 and 0.87%). The two ratios WT/R_D1 and TL/T_D2 across tissues (EW and LW) declined 0.59 and 4.56%, respectively. The decreased tracheid length and the ratio between tracheid length and diameter is disadvantageous for pulp production. The unfavorable relationship of tracheid traits with wood density indicate that multiple trait selection using optimal economic weights and optimal breeding strategies are recommended for the current longterm breeding program for P. tabuliformis.展开更多
The genetic variation of seed proteins was assayed by SDSPAGE for 24 cultivars belonging to 5 species in Vigna and 7 species in its 7 relative genera cultivated in China. There were 48 polymorphic subunit bands discri...The genetic variation of seed proteins was assayed by SDSPAGE for 24 cultivars belonging to 5 species in Vigna and 7 species in its 7 relative genera cultivated in China. There were 48 polymorphic subunit bands discriminated from electrophoretic profiles. Two dendrograms were constructed by UPGMA cluster analyses using PHYLIP3.6 respectively. Variation among genera or species was larger than that among lower taxonomic categories level. Little variation among cuhivars of yardlong bean (Vigna sesquipedalis ) and small variation of lablab ( Lablab purpureus), pea (Pisum sativum), or sword bean (Canavalia gladiata), but large variation of soybean or rice bean in their origin of China were all revealed. The seed proteins profiles of traditionally regarded as typical species in Vigna such as yardlong bean, rice bean and small bean were more similar than mungbean (Vigna radiata) and black gram (Vigna mungo) were. Mungbean and black gram had distinct seed proteins pattern, they should be of two species.展开更多
文摘Totally 26 provenance stands of 17-year-old Korean pine were selected for investigating wood properties and growth characters in Mao抏rshan Experimental Forest Farm of Northeast Forestry University in 1999. The anatomical property indexes, including tracheid length, tracheid diameter and wall-indiameter ratio, and the physical property indexes, such as growth ring width, late wood percentage and growth ring density, were measured for wood properties. Growth character indexes, including tree height and diameter at breast height, were also measured. The analytical results showed that there exited obviously dif-ference in wood property indexes between different provenances, which is suggested that wood properties are controlled by their genetic differences. The growth character indexes of Korean pines presented significant difference and they might also be controlled by their genetic differences. Most parameters of wood properties mainly varied in the direction of longitude, but the parameters of growth characters varied in the direction of latitude.
基金the Ministry of Education (No. NCET-04-0640)the National Natural Science Foundation of China (No. 30571442).
文摘Microsatellite DNA technique was used to detect the genetic variation between five hatchery populations of the Pacific oyster from China and two wild populations from Japan. Seven microsatellite loci screened in this study showed high polymorphism in both hatchery and wild populations, as observed in an average number of allele per locus (19.1-29.9) and average expected heterozygosity (0.916-0.958). No significant difference in average allelic richness or expected heterozygosity was observed between Chinese hatchery populations and Japanese wild populations. Pairwise Fsr values and heterogeneity tests of allele frequencies showed significant genetic differentiation between all populations. According to the neighbor-joining tree constructed on the basis of the Dc distance, the seven populations fell into three groups showing a clear division between hatchery and wild populations, and between the northern and southern hatchery populations. Assignment tests correctry assigned high percentages (97%-100%) of individuals to their original populations and demonstrated the feasibility of microsatellite analysis for discrimination between populations. The information obtained in this study is useful for designing suitable management guidelines and selective breeding programs for the Pacific oyster in China.
基金Supported by Natural Science Foundation of Jiangsu Province(BK20131334)Fund for Independent Innovation of Agricultural Science and Technology in Jiangsu Province[CX(13)3069]~~
文摘[Objective] This study aimed to investigate the genetic variation of g E gene of an epidemic pseudorabies virus(PRV) strain and its pathogenicity to piglets. [Method] By serial passage in Vero cells, a PRV strain was isolated from the brain tissues of stillborn fetuses delivered by sows with suspected PRV infection and preliminarily identified by PCR. g E gene of the isolated PRV strain was amplified and sequenced for phylogenetic analysis. In addition, the pathogenicity of the isolated PRV strain to 6-week-old piglets was evaluated. [Result] A PRV strain was successfully isolated and named PRV N5 B strain, which could proliferate in Vero cells and TCID50 of the 15 thgeneration virus liquid reached 10^7.125/0.1 ml. Specific bands could be amplified by PCR. g E gene in the isolated PRV strain was 1 740 bp in length. A phylogenetic tree was constructed based on full-length g E sequences, which showed that PRV N5 B strain and PRV strains isolated since 2012 were clustered into the same independent category and shared 99.7%-100% homology of nucleotide sequences. Compared with related sequences published previously, there were insertions of three consecutive bases at two loci. Animal experiments showed that intranasal inoculation of 6-week-old piglets with 2 ml of PRV N5 B strain(10^6/0.1 ml) led to a mortality rate of 100%. [Conclusion] In this study,genetic variability of g E gene in PRV N5 B isolate and its pathogenicity to piglets were analyzed, which provided a theoretical basis for the development of new vaccines to prevent and control porcine pseudorabies.
基金supported by the China Agriculture Research System(CARS-11,Sweetpotato)the National Natural Science Foundation of China(31461143017)
文摘The somatic hybrid KT1 was previously obtained from protoplast fusion between sweetpotato (Ipomoea batatas (L.) Lam.) cv. Kokei No. 14 and its wild relative I. triloba L. However, its genetic and epigenetic variations have not been investigated. This study showed that KT1 exhibited significantly higher drought tolerance compared to the cultivated parent Kokei No. 14. The content of proline and activities of superoxide dismutase (SOD) and photosynthesis were significantly increased, while malonaldehyde (MDA) content was significantly decreased compared to Kokei No. 14 under drought stress. KT1 also showed higher expression level of well-known drought stress-responsive genes compared to Kokei No. 14 under drought stress. Amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified polymorphism (MSAP) analyses indicated that KT1 had AFLP and MSAP band patterns consisting of both parent specific bands and changed bands. Fur- ther analysis demonstrated that in KT1. the proportions of Kokei No. 14 specific genome components and methylation sites were much greater than those of I. triloba. KT1 had the same chloroplast and mitochondrial genomes as Kokei No. 14. These results will aid in developing the useful genes ofI. triloba and understanding the evolution and phylogeny of the cultivated sweetpotato.
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.
文摘[Objective] This study aimed to investigate the prevalence and variation of porcine kobuvirus (PKV) in suckling piglets in China. [Method] In 2013-2014, 224 feces samples from suckling piglets with diarrhea in 27 pig farms of five provinces in China were collected to detect 3D genes of PKV with RT-PCR method; the sequences and genetic variation of 29 PKV 3D genes were analyzed. [Result] Total positive rate of PKV in feces samples from suckling piglets with diarrhea was 65.18% (146/224); total positive rate of PKV in pig farms was 85,2% (23/27); nucleotide sequences and the deduced amino acid sequences of 29 PKV 3D genes shared 87.0%-100% and 92.7%-100% homologies with six PKV-related 3D sequences, respectively. [Conclusion] PKV infection is prevalent in suckling piglets in China; PKV 3D genes exhibit high diversity.
基金Supported by Funds for Agricultural Science and Technology Innovation in Jiangsu Province (cx(10)424)~~
文摘[Objective] A total of 260 swine samples of dead or sick pigs collected from 7 provinces (municipalities) Jiangsu, Anhui, Shanghai, Shandong, Zhejiang, Fujian and Jiangxi of China during 2008-2010 were detected for porcine reproductive and respiratory syndrome virus (PRRSV). And the ORF5 genes of some isolates were amplified and sequenced for understanding the molecule epidemiology and the genetic evolution of PRRSV in East China. [Method] Using RT-PCR method, PRRSV was detected by RT-PCR from samples. The complete ORF5 genes of 36 PRRSV positive samples was amplified, sequenced and analyzed with other 15 strains available on GenBank. [Result] PRRSV was detected in 118/260 of the clinical samples, with a positive rate was 45.4%. Sequence analysis showed that the 36 isolates of this study belonged to the North American-type PRRSV strains and were closely related to the highly pathogenic PRRSV (HP-PRRSV) with 94.6%-100% amino acid sequence identities. The sequence analysis combined with the phylogenetic analysis indicated that all these North American-type PRRSV strains in East China were further divided into five subgenotypes, subgenotype Ⅲ showed closer identity with HPPRRSV; almost all subgenotypes were found to be variable in the primary neutralizing epitope; subgenotypes Ⅲ and IV had more glycosylation sites than others. Although these 36 isolates were collected from different provinces in East China, there were no obvious relations between the distribution of PRRSV and the region. [Conclusion] The PRRSV infection was widespread and HP-PRRSV was the popular strain in East China during 2008-2010. However some different genetic characteristics appeared in the genomes, the genetic evolution was relatively stable. There exists a cross-cutting phenomenon on the genetic relationship of PRRSV isolates obtained from different provinces. Subgenotypes IV and V only appeared in some provinces, but the distribution of PRRSV did not show apparent geographical characteristics.
基金Supported by National Natural Science Foundation of China(31302071)Special Fund for Agro-scientific Research in the Public Interest(201303046)+1 种基金Independent Innovation Project of Jiangsu Province[CX(13)3065]Project of the Fourth Period of "333" High-level Personnel Training Program of Jiangsu Province(BRA2012194)~~
文摘[Objective] This study aimed to investigate the genetic variation of porcine circovirus type 2 (PCV2) in China. [Method] The strain was isolated from infected samples by cel passage and preliminarily identified by PCR and IFA. Ful-length genome of the isolated strain was obtained by specific amplification for homology and phylogenetic analysis. [Result] A PCV2 strain was successful y isolated and named 201105ZJ, which could proliferate in PK15 cel lines. Specific fragments could be amplified by specific PCR assay. According to results of IFA assay, specif-ic immunofluorescence was observed; the TCID50 was low (102.67); the ful-length genome sequence of the isolated strain was 1 768 bp, sharing 94.1%-96.8% ho-mology with 13 reference strains; to be specific, the isolated strain exhibited the highest homology of 96.8% with AF055392PCV2a; the isolated strain 201105ZJ and reference strain AF055392 belonged to genotype PCV2a, exhibiting a distant genetic relationship with genotype PCV2c. [Conclusion] Characteristics of genetic variation of PCV2 isolate 201105ZJ provided theoretical basis for vaccine development, investi-gation of PCV2 pathogenesis, and prevention and control of porcine circovirus-as-sociated diseases (PCVAD) in East China.
基金The National Natural Science Foundation of China under grant Nos 39800105 and 30471328the Shanghai Development Foundation of Education under grant No. 98-SG-32Key Discipline of Shanghai Municipal Education Commission (J50701)
文摘For the population genetics analysis of the naturally grown brown seaweed Laminaria japonica (Laminariales,Phaeophyta) sampled from Dalian,Yantai,Weihai,Rongcheng and Qingdao in China,ten primers were employed to produce 88 bands as revealed by randomly amplified polymorphic DNA (RAPD) markers,and all these bands were polymorphic.According to these band patterns,there were 94 distinct phenotypes occurred in 100 samples indicating the high heterozygosity of this kelp.Dalian population samples showed the highest percentage of polymorphism (71.67%),and also the higher diversity estimated on the basis of the Shannon’s index (8.498),suggesting that this population could be chosen as the best resource for genetic breeding.The highest diversity of Yantai population possibly resulted from the introduction of L.longissima used for interspecific cross breeding with L.japonica cultivated in China.From Dalian southwards to Qingdao,the genetic variation of the five populations became less with a decrease in latitude,possibly due to the natural selection especially of high temperature.The genetic distance (Φ ST values) of the five populations was a little significantly correlated with the geographical distance (r=0.496) at P =0.05 by Mantel’s test.Weihai,Rongcheng and Yantai populations were closely grouped genetically together by Neighbor-joining cluster analysis probably in that the dispersal of the kelp by propagules more easily occurring in the range of relatively short distance.The analysis of molecular variance (AMOVA) also demonstrated that the relatively higher variation occurred among populations (71.49%) at an extremely significant level (P 0.000 1).All these evidence showed that there was a relatively distinct genetic differentiation among the sampled kelp populations,and L.japonica grown in China was also rather heterozygous in heredity.
基金the National High Technology Research and Development Program of China (863 Program,2006AA10Z179 and 2006AA10Z1F8)the National Excellent Doctoral Dissertation of China (200357 and 200458)the Key Technologies R&D Program of China (2006BAD01A02-23 and 2006BAD13B02)
文摘It was helpful for the wheat improvement to evaluate the genetic resources of Triticum turgidum L. ssp. turgidum landraces. In this study, 68 turgidum landraces accessions, belonging to four geographic populations in China, were investigated by using EST-SSR markers. A total of 63 alleles were detected on 22 EST-SSR loci, and the number of alleles on each locus ranged from 1 to 5, with an average of 2.9. The results of the analysis of molecular variance (AMOVA) indicated that 92.5% of the total variations was attributed to the genetic variations within population, whereas only 7.5% variations among populations. Although the four populations had similar genetic diversity parameters, Sichuan population was yet distinguished from other populations when comparing the population samples in pairs. Significant correlations were detected by the statistic analysis among six genetic diversity parameters among each other. The selection difference between heterozygosty and homozygosty was also observed among different EST-SSR locus. The genetic similarity (GS) ranged from 0.18 to 0.98, with the mean of 0.72, and all accessions could be clustered into 7 groups. The dendrogram suggested that the genetic relationships among turgidum accessions evaluated by EST-SSR markers were unrelated to their geographic distributions. These results implied that turgidum landraces from China had the unique characters of genetic diversity.
基金This study was supported by National Scientific and Technological Brainstorm Project.
文摘Inter Simple Sequence Repeat (ISSR) was used to detect genetic variation among nine provenances, including 135 individuals. A total of 108 loci were amplified using 10 random primers. The differentiation of the percentage of polymorphic bands (PPB) among different provenances was evident, ranging from 27% to 54%. of which Honghuaerji provenance had the highest PPB and Kalunshan provenance had the lowest PPB. Shannon's Information index (1) at species level was 0.1581 and Nei's gene diversity (h) was 0.2393. Coefficient of gene differentiation (Gsr) calculated by Popgene was 0.3965, these results indicated that majority of genetic variation (60.35%) was found within provenances. According to dendrogram among pinus sylvestriv provenances, nine provenances were divided into two provenance areas. namely Daxing'an and Xiaoxing'an Mountains provenance area and Hulunbeier provenance area.
基金supported by subproject of National Program on Key Basic Research Project (973 Program )(2005CB523001)
文摘A Objective3 This study was to understand the genetic variation characters of the H9N2 subtype avian influenza virus isolate (A/Chicken/ Hebei/WD/98, abbreviated as WD98) by comparing with other reference strains. I-Method3 Eight complete genes were amplified by RT-PCR and sequenced. The homology and genetic evolution relationship were analyzed between these sequences and that of the seven reference strains. [Result] The whole genomic sequence of WD98 strain was 91.1% -95.8% homologous to that of seven reference strains tested. This isolate shared the highest homology (95.8%) to D/HK/Y280/97 and the lowest homology (91.1% ) to C/Pak/2/99. The HA cleavage site of the WD98 strain was R-S-S-R G, and the 226th amino acid at receptor-binding site was Gin. [ Condmion] WD98 strain belongs to mildly pathogenic avian in- fluenza virus and may not infect human. The genetic relationship is the closest between A/Chicken/Hebei/wD/98 and A/duck/HongKong/Y280/ 97, both of which belong to the sub-line of A/Chicken/Beijing/1/94 in Eurasian line. And A/Chicken/Hebei/WD/98 and A/Chicken/Beijing/1/94 are genetically distant within the same sub-line.
基金Supported by The National Natural Science Foundation of China,No.30800926,No.30872084,No.81001274,and No.30972444the Natural Science Foundation of Jiangsu Province,No.BK2010080
文摘AIM:To explore the association between mothers against decapentaplegic homolog 4 (SMAD4) gene polymorphisms and gastric cancer risk.METHODS:Five tagging single nucleotide polymor-phisms (tSNPs) in the SMAD4 gene were selected and genotyped in 322 gastric cancer cases and 351 cancerfree controls in a Chinese population by using the polymerase chain reactionrestriction fragment length polymorphism method.Immunohistochemistry was used to examine SMAD4 protein expression in 10 normal gastric tissues adjacent to tumors.RESULTS:In the single-locus analysis,two significantly decreased risk polymorphisms for gastric cancer were observed:the SNP3 rs17663887 TC genotype (adjusted odds ratio=0.38,95% confidence interval:0.21-0.71),compared with the wild-type TT genotype and the SNP5 rs12456284 GG genotype (0.31,0.16-0.60),and with the wild-type AA genotype.In the combined analyses of these two tSNPs,the combined genotypes with 2-3 protective alleles (SNP3 C and SNP5 G allele) had a significantly decreased risk of gastric cancer (0.28,0.16-0.49) than those with 0-1 protective allele.Furthermore,individuals with 0-1 protective allele had significantly decreased SMAD4 protein expression levels in the norma tissues adjacent to tumors than those with 2-3 protective alleles (P=0.025).CONCLUSION:These results suggest that genetic variants in the SMAD4 gene play a protective role in gastric cancer in a Chinese population.
基金supported by the National Natural Science Foundation of China(No,30471329)the National Key Basic Research Program from the Ministry of Science and Technology,P.R.China(2005CB422306)High-Tech Development Program of China(863 Program)(2006AA09Z418).
文摘To investigate the genetic structures and differentiation of different wild populations of white croaker (Pennahia argentara), horizontal starch gel electrophoresis was performed on 133 individuals collected from five different locations in China and Japan. The eleven enzyme systems revealed 15 loci, of which eleven were polymorphic. The percentage ofpolymorphic loci of white croaker populations varied from 6.67% to 53.3.3%; the mean observed and expected heterozygosity ranged from 0.0033 to 0.0133 and 0.0032 to 0.0191, respectively. The expected heterozygosity revealed a low genetic variability for white croaker in comparison with other marine fishes. The genetic distances between populations ranged from 0.00005 to 0.00026. A weak differentiation was observed within each clade and between clades; and no significant differences in gene frequencies among populations were observed in white croaker. Among the five populations, three Chinese populations showed more genetic diversity than that in Japanese populations.
基金Supported by the Natural Science Fundation of China (No. 30571445)Natural Science Fundation of Shandong Province of China
文摘Population genetics of the left-eyed flounder, Paralichthys olivaceus, including natural and cultured stocks distributed in the coastal waters near Qingdao of eastern maritime China, was analyzed in allozyme and RAPD. The results showed that among total 29 gene loci of 15 isozymes, 9 and 7 were po- lymorphic in natural and cultured stocks, respectively. The status of genetic diversity in P. olivaceus is low in terms of polymorphic loci in chi-square test and genetic departure index of Hardy-Weinberg equi- librium. More alleles in IDHP, CAT, GDH and Ldh-C allozymes were found in the fish, which could be used as markers in assortive breeding and distinguishing stock, population or species evolution. Total 88 and 86 RAPD bands ranging from 200 to 2 500 bp were recognized individually in average of 7.8–8.0 bands per primer. The genetic diversity in cultured stock is lower than that in natural ones showing an ob- viously decreasing genetic divergence. Therefore, effective countermeasures must be taken to protect ge- netic resources of marine cultured fishes. The 2 markers have their own pros and cons. Combining the 2 markers to investigate the genetic variation of populations is suggested. The results provide basic data of this flounder and they are useful for studying genetic improvement and genetic resources of the fish.
基金supported by grants from the National High Technology Research and Development Program (2012AA10A405-6)National Natural Science Foundation of China (31372524)Special Fund for Independent Innovation of Shandong Province (2013CX80202)
文摘Abstract Four successive mass selection lines of the Pacific oyster, Crassostrea gigas, selected for faster growth in breeding pro- grams in China were examined at ten polymorphic microsatellite loci to assess the level of allelic diversity and estimate the effective population size. These data were compared with those of their base population. The results showed that the genetic variation of the four generations were maintained at high levels with an average allelic richness of 18.8-20.6, and a mean expected heterozygosity of 0.902-0.921. They were not reduced compared with those of their base population. Estimated effective population sizes based on temporal variances in microsatellite frequencies were smaller to that of sex ratio-corrected broodstock count estimates. Using a rela- tively large number ofbroodstock and keeping an equal sex ratio in the broodstock each generation may have contributed to retaining the original genetic diversity and maintaining relatively large effective population size. The results obtained in this study showed that the genetic variation was not affected greatly by mass selection progress and high genetic variation still existed in the mass selection lines, suggesting that there is still potential for increasing the gains in future generations of C. gigas. The present study provided im- portant information for future genetic improvement by selective breeding, and for the design of suitable management guidelines for genetic breeding of C. gigas.
文摘Horizontal starch gel electrophoresis was used to investigate the biochemical genetic structure of Chinese mitten crab Eriocheir sinensis and Hepu mitten crab E.hepuensis. Sixteen putative enzyme-coding loci were examined for forty-nine Chinese mitten crabs and thirty-eight Hepu mitten crabs. Nine loci, AAT-1 *, AAT-2 *, G3PDH *, GPI *, IDHP-1 *, IDHP-2 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Chinese mitten crab, and seven, AAT-1 *, AAT-2 *, GPI *, IDHP-1 *, MDH-1 *, MDH-2 * and PGM *, are polymorphic in Hepu mitten crab. The proportion of polymorphic loci and the expected heterozygosity are 0.562 5 and 0.080 3 for Chinese mitten crab, and 0.437 5 and 0.075 4 for Hepu mitten crab. The Nei’s genetic distance between two species is 0.002 4.
基金supported by the National Natural Science Foundation of China (NSFC31872105 and 31801862)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences, and the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture and Rural Affairs, China
文摘DNA methylation plays an important role in plant growth and development,and in regulating the activity of transposable elements(TEs).Research on DNA methylation-related(DMR)genes has been reported in Arabidopsis,but little research on DMR genes has been reported in Brassica rapa and Brassica oleracea,the genomes of which exhibit significant differences in TE content.In this study,we identified 78 and 77 DMR genes in Brassica rapa and Brassica oleracea,respectively.Detailed analysis revealed that the numbers of DMR genes in different DMR pathways varied in B.rapa and B.oleracea.The evolutionary selection pressure of DMR genes in B.rapa and B.oleracea was compared,and the DMR genes showed differential evolution between these two species.The nucleotide diversity(π)and selective sweep(Tajima’s D)revealed footprints of selection in the B.rapa and B.oleracea populations.Transcriptome analysis showed that most DMR genes exhibited similar expression characteristics in B.rapa and B.oleracea.This study dissects the evolutionary differences and genetic variations of the DMR genes in B.rapa and B.oleracea,and will provide valuable resources for future research on the divergent evolution of DNA methylation between B.rapa and B.oleracea.
基金supported by “Open Fund of State Key Laboratory of Tree Genetics and Breeding(Chinese Academy of Forestry)(Grant No.TGB2016001)”“The Lecture and Study Program for Outstanding Scholars from Home and Abroad(Grant No.CAFYBB2011007)”“Continuation project of National Natural Science Foundation of China(Grant No.CAFNSFC201601)”
文摘To improve wood quality for pulpwood industries, it is important to examine not only wood density but also its components, especially tracheid characteristics. We studied genetic variations in the following tracheid traits by earlywood (EW) and latewood (LW): tracheid length (TL), double wall thickness (WT), radial lumen diameter (R_D1), tangential lumen diameter (T_D1), radial central diameter (R_D2), and tangential central diameter (T_D2). We also studied the relationship with the following growth traits: diameter at breast height (DBH), height (H), crown breadth south-north axis (NSC), crown breadth east-west axis (EWC), ring width (RW), latewood percentage (LWP), and wood density (WD). All sample materials were collected from a 33-year old clonal seed orchard of Pinus tabuliformis Carr. Genetic variation among clones was moderate for all tracheid traits, 9.49-26.03%. Clones significantly affected WT, R_D1, R_D2, T_D1, T_D2, and the two ratios WT/R_D1 and TL/T_D2 in EW but had no effects in LW. Clones significantly affected TL in LW but had no effects in EW. H2/C was higher in LW (0.50) than in EW (0.20) for TL, while H 2/C was higher in EW (0.27-0.46) for other tracheid traits and the two ratios (TL/T_D2 and WT/R_D1) than in EW (0.06-0.22). WD and TL were significantly positively correlated, but WT and TL were negatively correlated both at individual and clone levels; all tracheid diameters and the four ratio values (EW_WT/ R_D1, LW WT/R_D1, EW_TL/T_D2 and LW_TL/ T_D2), were strongly positively correlated with DBH, H, NSC, WEC and RW, and strongly negatively correlated with WD both at individual and clone levels. The most important variables for predicting WD were LW_TL, EW_WT and R_D1 in both EW and LW (r2= 0.22). Selecting the top 10% of the clones by DBH would improve DBH growth by 12.19% (wood density was reduced by 0.14%) and produced similar responses between EW and LW for all tracheid traits: a reduction of 0.94 and 3.69% in tracheid length and increases in tracheid diameters (from 0.36 to 5.24%) and double wall thickness (0.07 and 0.87%). The two ratios WT/R_D1 and TL/T_D2 across tissues (EW and LW) declined 0.59 and 4.56%, respectively. The decreased tracheid length and the ratio between tracheid length and diameter is disadvantageous for pulp production. The unfavorable relationship of tracheid traits with wood density indicate that multiple trait selection using optimal economic weights and optimal breeding strategies are recommended for the current longterm breeding program for P. tabuliformis.
基金Supported by Scientific Research Programof Wuhan Municipali-ty, Hubei Province ,China (20015007090) .
文摘The genetic variation of seed proteins was assayed by SDSPAGE for 24 cultivars belonging to 5 species in Vigna and 7 species in its 7 relative genera cultivated in China. There were 48 polymorphic subunit bands discriminated from electrophoretic profiles. Two dendrograms were constructed by UPGMA cluster analyses using PHYLIP3.6 respectively. Variation among genera or species was larger than that among lower taxonomic categories level. Little variation among cuhivars of yardlong bean (Vigna sesquipedalis ) and small variation of lablab ( Lablab purpureus), pea (Pisum sativum), or sword bean (Canavalia gladiata), but large variation of soybean or rice bean in their origin of China were all revealed. The seed proteins profiles of traditionally regarded as typical species in Vigna such as yardlong bean, rice bean and small bean were more similar than mungbean (Vigna radiata) and black gram (Vigna mungo) were. Mungbean and black gram had distinct seed proteins pattern, they should be of two species.