Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes ...Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes that run through his works.His novel Never Let Me Go tells a story of a group of clones growing up in the Hailsham,who are given the mission to donate organs at birth.So,there is no doubt that they will inevitably end their lives in the process of donating organs to human beings again and again.The tragic life of clones is determined by the motivation of human to create them.展开更多
With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the pr...With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the process of their identity quest as well as role identification.Through the specific analysis,it is concluded that the clones,represented by Kathy,Tommy and Ruth,have gained self-certainty and social identity by realizing the role identity as a“carer”and a“donor”,in the meantime,they have constructed their identity as social persons with souls like ordinary people.Furthermore,the findings shows that Never Let Me Go is actually a microcosm of human’s quest for identity.Ishiguro aims to express his meditation on human life in the novel:human life is a process of seeking self-identity and social roles,and then fulfilling the obligations of the roles,which confirms Ishiguro’s internationalism that he attempts to convey his contemplation on human existence through his works.展开更多
There are lots of code clones appearing in software,which are similar code fragments with each other. In the past decades,researchers have proposed some state-of-the-art methods to detect clones. The code clones have ...There are lots of code clones appearing in software,which are similar code fragments with each other. In the past decades,researchers have proposed some state-of-the-art methods to detect clones. The code clones have showing some relationship with the evolution of software. In order to explore relationships between clones and their evolution,we propose a framework to cluster clones with a Fuzzy C-means clustering method.Firstly,we detect all the clones using Ni Cad,and build the clone genealogies for multiple versions software.Secondly,we extract some metrics to describe the clones and their evolution. Finally,we cluster all clone's vectors,which are generated with the different metrics for different proposes. Experimental results on six open source software packages have shown the relationships among the clone life,the number of change times,the clone pattern and et al. can help developers to understand clones.展开更多
[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, r...[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.展开更多
[Objective] The research aimed to study the rapid propagation technology and establish effective clone of Hemistepta lyrata Bunge. [Method] With tender stem of Hemistepta lyrata Bunge as material, the conditions neede...[Objective] The research aimed to study the rapid propagation technology and establish effective clone of Hemistepta lyrata Bunge. [Method] With tender stem of Hemistepta lyrata Bunge as material, the conditions needed in calluses induction and differentiation, adventitious bud differentiation and radication, test tube seedling cutting and transplantation were studied. [ Result] The results showed that the optimum medium for granulated calluses induction from tender stem was MS + BA 0.3 mg/L +2,4-D 1 -1.5 mg/L, for granulated calluses and adventitious bud differentiation was MS + AgNO31.5 mg/L + BA 0.4 mg/L + NAA 0.1 mg/L. 1/2 MS + IAA 0.6 mg/L was suitable for test tube seedling rooting and regeneration, and cinder was used as transplantation and cutting substrate. [ Conclusion]This study will provide the scientific reference for choosing the feasible medium in tissue culture of Hemistepta lyrata Bunge.展开更多
In order to provide directionally genetically improved breeding materials of poplar by exploring the phenological traits genetic variation level and its develop- ment potential of Populus deltoides and the resource ev...In order to provide directionally genetically improved breeding materials of poplar by exploring the phenological traits genetic variation level and its develop- ment potential of Populus deltoides and the resource evaluation was carried out; 8 phenological phases in seedling period were observed and analyzed of 60 Populus deltoids clones introduced from America. The results showed that: (1) there was obvious difference in phonological character among clones, especially in leaf-spread- ing peak stage and the end term of leaf-falling stage, with the largest variation co- efficient of 14.97% and the minimum of 3.83% respectively. (2) Leaf-spreading peak stage scattered but the end term of leaf-falling stage concentrated the most. The phonological character in early stage of seedling growth was the main factor influ- encing the length of growing season. (3) By principal component analysis, pheno- logical phases were classified into 3 typical periods, including germination stage, leaf-spreading peak stage and leaf-falling stage. (4) Totaling 60 clones were classi- fied into 4 types by using clustering analysis in phenological time variables of clones.展开更多
[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to d...[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances(free proline,soluble sugar and soluble protein) in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level(CK, with soil water content of 97.49% and leaf water potential of-0.54MPa), light drought(LD with soil water content of 59.96% and leaf water potential of-1.28 MPa), mediate drought(MD with soil water content of 34.19% and leaf water potential of-2.32 MPa) and severe drought(SD with soil water content of 14.52%and leaf water potential of-2.99 MPa). The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3(P0.001). The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress(P 0.001). To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level(P0.001); the free proline content of Catalpa bungei clone 1-3 rapidly increased to(855.46±227.52) μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached(1.644 ±0.137)mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress.展开更多
Cutting propagation rhizogenesis of Toona ciliata clone cutting orchard were studied, and the results were as fol ows: Rooting type included both cal us rooting and cortex rooting. About 17 in 22 of clones were domin...Cutting propagation rhizogenesis of Toona ciliata clone cutting orchard were studied, and the results were as fol ows: Rooting type included both cal us rooting and cortex rooting. About 17 in 22 of clones were dominated by cortex rooting, accounting for the 77% of clones. There were 5 clones which occurred with both cal us rooting and cortex rooting during rooting process. The rooting efficiency index (REI) showed a positive correlation with the rooting rate. Under natural tem-perature condition, keeping moisture and shading, we found that the highest survival rate occurred in early June, September, and October.展开更多
[Objective] This study aimed to provide scientific basis for the early selec-tion and breeding of excellent Catalpa bungei clones. [Method] The Li-6400 portable photosynthesis system was used to analyze the photosynth...[Objective] This study aimed to provide scientific basis for the early selec-tion and breeding of excellent Catalpa bungei clones. [Method] The Li-6400 portable photosynthesis system was used to analyze the photosynthetic characteristics of five Catalpa bungei clones (1-3, 1-4, 004-1, 015-1 and 7080). [Result] Al five Catalpa bungei clones had similar change trends of light response curves, but their maxi-mum net photosynthetic rates (Pmax) were in the order of 1-3>7080>015-1>004-1>1-4, showing that clone 1-3 and clone 7080 had strong light environmental adapt-ability with the light saturation points (LSP) of 1 147.97 μmol/m2·s and 1 196.31μmol/m2·s, respectively, while clone 1-4 had the narrowest range of adaptation to light. There were differences in the total photosynthetic amount per area among the five clones that clone 1-4 was the best of 433 974.24 μmol/m2, fol owed by clone 1-3 of 401 290.20 μmol/m2. The transpiration rates (Tr) and stomatal conductances (Cond) of the five clones presented the same change trend. And the diurnal varia-tion curves of net photosynthetic rate (Pn) of clone 1-3, 1-4 and 015-1 showed two typical peaks with obvious midday depression, while clone 004-1 and 7080 didn’t. [Concluson] Considering a variety of photosynthetic characteristics of indica-tors, photosynthetic capacity of clone 1-3 was the best among the five Catalpa bungei clones.展开更多
Poplar is one of the dominant tree species for the establishment of fast growing plantations in Shandong Province. Eighteen poplar clones belonging to Populus aigeiros section were introduced from Italy, Turkey and do...Poplar is one of the dominant tree species for the establishment of fast growing plantations in Shandong Province. Eighteen poplar clones belonging to Populus aigeiros section were introduced from Italy, Turkey and domestic regions. Populus deltoides cv. 慙ux?I-69/55 (I-69), which was widely used in Shandong Province, China, was taken as control clone (I-69). Following a randomized complete block design, seedling test and controlled afforestation trials were carried out at Juxian County, Caoxian County and Laiyang City. The results showed that the poplar clone (Populus ?euramericana cv. ?02/74?, namely 102/74, performed well both in terms of adaptability and growth rate. The mean height of 13.9 m (H), diameter at breast height of 18.0 cm (DBH) and volume growth of 0.1445 m3 (V) were 2.2 %, 21.6% and 52.9 % higher than those of I-69 (CK), respectively, at the age of 5 years at three experimental sites. Moreover, the clone can be propagated easily and showed high resistance to poplar disease, pest as well as salinity and had longer growing period. Furthermore, wood basic density and fiber length of new poplar clone (102/74) were as same as I-69 (CK). It was concluded that the selected clone (102/74) was ideal for the estab-lishment of fast-growing poplar plantations, especially for the pulpwood plantations in Shandong Province.展开更多
The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood...The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood density and some mechanical properties. The results showed that significant or extremely significant difference in air dried wood density and the mechanical properties existed among the clones, this means these wood properties were under moderate or strong genetic controls and could be improved by genetic manipulations. The radial and vertical variation patterns of air dried wood density were also studied and the results were found to coordinate with other previous research results. The vertical variation patterns of most mechanical properties within the individual tree also conformed to the general wood theories except the modulus of elasticity and cross section hardness. Among the mechanical properties, modulus of elasticity (MOE) and tangent section hardness were under strong genetic control, with the clonal repeatabilities being 0 90 and 0 80, respectively. However, the clonal repeatabilities of other mechanical properties under study were a little lower than above two indexes. Genetic correlation analysis indicated that super clonal selection and breeding for veneer timber could be realized through indirect selection of wood density and form indexes.展开更多
[Objective] The aim was to study the effects of drought stress on contents of endogenous hormones in leaves of different clones of Liriodendron chinense×L. tulipifera. Drought-resistant Liriodendron chinense×...[Objective] The aim was to study the effects of drought stress on contents of endogenous hormones in leaves of different clones of Liriodendron chinense×L. tulipifera. Drought-resistant Liriodendron chinense×L. tulipifera clones NE25,NE78 and drought-sensitive Liriodendron chinense×L. tulipifera clones NE04,NE23 were selected as experimental materials to study the content changes of four kinds of endogenous hormones such as abscisic acid (ABA),indoleacetic acid (IAA),ribosylzeatin (ZR) and jasmonic acid (JA) in leaves of different clones under drought stress. [Result] Under drought stress,ABA was accumulated I leaves of different clones,however,the content changes in drought-resistant clones were not obvious; IAA content showed a decreasing trend,and the content changes n drought-resistant clones during later period of drought stress was decreased; JA content showed an increasing trend in leaves of drought-sensitive clones,indicating that drought-sensitive clones had to maintain higher contents of JA to resist drought stress. [Conclusion] The result of this study had provided scientific basis for the screening,planting and application of drougt-resistant clones of Liriodendron chinense×L. tulipifera.展开更多
Reusing code fragments by copying and pasting them with or without minor adaptation is a common activity in software development.As a result,software systems often contain sections of code that are very similar,called...Reusing code fragments by copying and pasting them with or without minor adaptation is a common activity in software development.As a result,software systems often contain sections of code that are very similar,called code clones.Code clones are beneficial in reducing software development costs and development risks.However,recent studies have indicated some negative impacts as a result.In order to effectively manage and utilize the clones,we design an approach for recommending refactoring clones based on a Bayesian network.Firstly,clone codes are detected from the source code.Secondly,the clones that need to be refactored are identified,and the static and evolutions features are extracted to build the feature database.Finally,the Bayesian network classifier is used for training and evaluating the classification results.Based on more than 640 refactor examples of five open source software developed in C,we observe a considerable enhancement.The results show that the accuracy of the approach is larger than 90%.We believe our approach will provide a more accurate and reasonable code refactoring and maintenance advice for software developers.展开更多
The oxygen evolution, thermal dissipation, and photochemical energy storage of three hybrid poplar clones, namely the triploid clone B342, the diploid clone B11 [(Populus alba×P. glandulosa)×(P.tomentosa...The oxygen evolution, thermal dissipation, and photochemical energy storage of three hybrid poplar clones, namely the triploid clone B342, the diploid clone B11 [(Populus alba×P. glandulosa)×(P.tomentosa×P.bolleana)], and the triploid clone B346 [(P.tomentosa×P. bolleana)×(P. alba×P.glandulosa)], under light stress were studied using photoacoustics. The oxygen evolution signal and photochemical energy storage varied negatively with the pretreatment_PFD (photon flux density), whereas the thermal signal varied positively with the pretreatment_PFD. Photochemical energy storage was reallocated to PSⅡ more than to PSⅠ, while the photochemical energy storage in PSⅠ was more stable than that in PSⅡ when subjected to light stress. The inhibitors streptomycin (SM), dithiothreitol (DTT) and sodium fluoride (NaF) could all affect the oxygen evolution signal. Clones B11 and B342 were more resistant to light stress than clone B346.展开更多
AIM: To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS: Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97, a...AIM: To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS: Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97, and biological characteristics of the target clones selected by in vivo screening were studied. RESULTS: Two clones with high (MHCC97-H) and low (MHCC97-L) metastatic potential were isolated from the parent cell line. Compared with MHCC97-L, MHCC97-H had smaller cell size (average cell diameter 43 microm vs 50 microm) and faster in vitro and in vivo growth rate (tumor cell doubling time was 34.2h vs 60.0h). The main ranges of chromosomes were 55-58 in MHCC97-H and 57-62 in MHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was (37.5 +/- 11.0) cells/field for MHCC97-H vs (17.7 +/- 6.3)/field for MHCC97-L. The proportions of cells in G0-G1 phase, S phase, and G2-M phase for MHCC97-H/MHCC97-L were 0.56/0.65, 0.28/0.25 and 0.16/0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5wk after orthotopic implantation of tumor tissue were (246 +/- 66) microg.L(-1) for MHCC97-H and (91 +/- 66) microg.L(-1) for MHCC97-L. The pulmonary metastatic rate was 100% (10/10) vs 40% (4/10). CONCLUSION: Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.展开更多
Mapping of low or single-copy sequences on plant chromosomes has proven difficult because of very low frequency of signal detection. Rice BAC library is being used widely in rice genome research due to its distinctive...Mapping of low or single-copy sequences on plant chromosomes has proven difficult because of very low frequency of signal detection. Rice BAC library is being used widely in rice genome research due to its distinctive advantages over other library systems. In this study, two biotin-labeled rice BAC clones closely linked to a rice blast resistance, green leafhopper resistance and tungro spherical virus resistance gene,Pi-5(t), Glh, RTSV, werein situ hybridized to rice chromosomes. They were located on the long arm and short arm of chromosome 4 with FL value of 40%and 100%respectively. The frequency of signal detection reached 46.8%and 59.2%. The signal location were consistent with the selective marker on rice saturated molecular map. The results demonstrated the advantages to locate BAC clones to chromosomes byin situ hybridization and will facilitate the rice low or single-copy gene location by using the BAC library.展开更多
Methamidophos was widely used a pesticide in northern China. The potential influences of methamidophos on soil fungal community in black soil were assessed by plate count, 28S rDNA-PCR-DGGE, and clone library analysis...Methamidophos was widely used a pesticide in northern China. The potential influences of methamidophos on soil fungal community in black soil were assessed by plate count, 28S rDNA-PCR-DGGE, and clone library analysis. Three methamidophos levels (50, 150, and 250 mg/kg) were tested in soil microcosms. Results from plate count during a 60-d microcosm experiment showed that high concentrations of methamidophos (250 mg/kg) could significantly stimulate fungal populations. DGGE (denaturing gradient gel electrophoresis) fingerprinting patterns showed a significant difference between the responses of culturable and total fungi communities under the stress of methamidophos. Shannon diversity indices calculated from DGGE profiles indicated that culturable fungi in all microcosms with methamidophos treatment increased after 1 week of incubation. However, the diversity indices of total fungi decreased in the first week, as compared to the stimulation of culturable fungi. At the 8th week, however, all the microcosms treated by methamidophos were similar to the control microcosms in community structure as suggested by the Shannon diversity indices for both culturable and total fungi. In contrast, after 1 week the fungal structure of culturable and unculturable both were disturbed to different extent under the stresses of methamidophos by clustering analysis. Clone sequencing analysis indicated the stimulation of pathogenic and unculturable fungal populations by methamidophos treatment, suggetsing potential risks of plant disease outbreak.展开更多
文摘Japanese British writer Kazuo Ishiguro is one of the leading writers in contemporary British literature.He has always been committed to creating works with universal significance.Responsibility and destiny are themes that run through his works.His novel Never Let Me Go tells a story of a group of clones growing up in the Hailsham,who are given the mission to donate organs at birth.So,there is no doubt that they will inevitably end their lives in the process of donating organs to human beings again and again.The tragic life of clones is determined by the motivation of human to create them.
文摘With the guidance of Erikson’s identity theory,the article analyzes the clones’identity exploration through role identification in Never Let Me Go.It interprets the clones’puzzlement about their identity,and the process of their identity quest as well as role identification.Through the specific analysis,it is concluded that the clones,represented by Kathy,Tommy and Ruth,have gained self-certainty and social identity by realizing the role identity as a“carer”and a“donor”,in the meantime,they have constructed their identity as social persons with souls like ordinary people.Furthermore,the findings shows that Never Let Me Go is actually a microcosm of human’s quest for identity.Ishiguro aims to express his meditation on human life in the novel:human life is a process of seeking self-identity and social roles,and then fulfilling the obligations of the roles,which confirms Ishiguro’s internationalism that he attempts to convey his contemplation on human existence through his works.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61173021)
文摘There are lots of code clones appearing in software,which are similar code fragments with each other. In the past decades,researchers have proposed some state-of-the-art methods to detect clones. The code clones have showing some relationship with the evolution of software. In order to explore relationships between clones and their evolution,we propose a framework to cluster clones with a Fuzzy C-means clustering method.Firstly,we detect all the clones using Ni Cad,and build the clone genealogies for multiple versions software.Secondly,we extract some metrics to describe the clones and their evolution. Finally,we cluster all clone's vectors,which are generated with the different metrics for different proposes. Experimental results on six open source software packages have shown the relationships among the clone life,the number of change times,the clone pattern and et al. can help developers to understand clones.
基金Supported by National Key Technology R&D Program during the 11th Five-year Plan Period(2006BAD32B01)~~
文摘[Objective] The experiment was aimed to select effective and economical media for container seedling of triploid clones of Populus tomentosa that was carried out. [Method] The sandy loam, peat, perlite, vermiculite, riversand, sludge were taken as media of hardwood cutting and survival rate, seedling height were taken as indexes to select media for container seedling of triploid clones of Populus tomentosa. [Result] Different mixedmedia had great influence on survival rates of container seedlings. Taking peat and vermiculite with the proportion of 5∶2 (M10) or peat ,vermiculite with the proportion of 7∶2 (M11) or sandy loam (M1) as media would generate higher cutting survival rate that was higher than 90.0%. There were significant differece in height increments of container seedlings. Taking sandy loam, peat and vermiculite with the proportion of 6∶2∶2(M5)or sandy loam (M1), seedling height of 60-days the seedling was over 37.0 cm. [Conclusion] According to cost analysis of nursery medium, the optimum medium for hardwood cuttings container seedling-raising of triploid clones of Populus tomentosa was sandy loam.
文摘[Objective] The research aimed to study the rapid propagation technology and establish effective clone of Hemistepta lyrata Bunge. [Method] With tender stem of Hemistepta lyrata Bunge as material, the conditions needed in calluses induction and differentiation, adventitious bud differentiation and radication, test tube seedling cutting and transplantation were studied. [ Result] The results showed that the optimum medium for granulated calluses induction from tender stem was MS + BA 0.3 mg/L +2,4-D 1 -1.5 mg/L, for granulated calluses and adventitious bud differentiation was MS + AgNO31.5 mg/L + BA 0.4 mg/L + NAA 0.1 mg/L. 1/2 MS + IAA 0.6 mg/L was suitable for test tube seedling rooting and regeneration, and cinder was used as transplantation and cutting substrate. [ Conclusion]This study will provide the scientific reference for choosing the feasible medium in tissue culture of Hemistepta lyrata Bunge.
基金Supported by National Special Funds for Forest Research in the Public Interest(201004004)~~
文摘In order to provide directionally genetically improved breeding materials of poplar by exploring the phenological traits genetic variation level and its develop- ment potential of Populus deltoides and the resource evaluation was carried out; 8 phenological phases in seedling period were observed and analyzed of 60 Populus deltoids clones introduced from America. The results showed that: (1) there was obvious difference in phonological character among clones, especially in leaf-spread- ing peak stage and the end term of leaf-falling stage, with the largest variation co- efficient of 14.97% and the minimum of 3.83% respectively. (2) Leaf-spreading peak stage scattered but the end term of leaf-falling stage concentrated the most. The phonological character in early stage of seedling growth was the main factor influ- encing the length of growing season. (3) By principal component analysis, pheno- logical phases were classified into 3 typical periods, including germination stage, leaf-spreading peak stage and leaf-falling stage. (4) Totaling 60 clones were classi- fied into 4 types by using clustering analysis in phenological time variables of clones.
基金Supported by National Scientific and Technological Project in Rural Areas in the "Twelfth Five Year" Plan(2012BAD21B03,2012BAD21B0304)~~
文摘[Objective] This study aimed to investigate the effects of drought stress on osmotic regulation substances of Catalpa bungei clones. [Method] Potting experimental was carried out with plastic film sealing method, to differentiate the degrees of drought stress based on changes in soil water content and leaf water potential and investigate variations in contents of osmotic regulation substances(free proline,soluble sugar and soluble protein) in leaves of five Catalpa bungei clones under different degrees of drought stresses. [Result] According to changes in soil water content and leaf water potential, the whole process of drought stress was divided into normal level(CK, with soil water content of 97.49% and leaf water potential of-0.54MPa), light drought(LD with soil water content of 59.96% and leaf water potential of-1.28 MPa), mediate drought(MD with soil water content of 34.19% and leaf water potential of-2.32 MPa) and severe drought(SD with soil water content of 14.52%and leaf water potential of-2.99 MPa). The soil water content and leaf water potential of five Catalpa bungei clones reached the highest correlation in exponential fitting, with an average R2of 0.989 3(P0.001). The free proline content in leaves of five Catalpa bungei clones increased rapidly with the increasing degree of drought stress(P 0.001). To be specific, free proline contents of Catalpa bungei clones015-1 and 7080 were 34.39 and 33.41 times of the normal level under severe drought conditions, which reached an extremely significant level(P0.001); the free proline content of Catalpa bungei clone 1-3 rapidly increased to(855.46±227.52) μg/g Fw under light drought conditions. The soluble protein content in leaves showed different variation trends. To be specific, the soluble protein content of Catalpa bungei clone 7080 was the lowest at various drought stages and reached(1.644 ±0.137)mg/g Fw under normal conditions; the soluble protein content of Catalpa bungei clone 1-3 was relatively high under normal conditions and was reduced rapidly under light drought conditions, showing different response patterns. [Conclusion] Osmotic regulation substances in leaves of five Catalpa bungei clones all have certain response to drought stress. Free proline is the most important osmotic regulation substance, followed by soluble protein, while soluble sugar makes no significant contribution. According to changes in content of osmotic regulation substances, Catalpa bungei clone 7080 has relatively high capacity and good drought resistance, while Catalpa bungei clone 1-3 has the rapidest response to drought stress.
基金Supported by Hunan Forestry Science and Technology Project(XLK201406)~~
文摘Cutting propagation rhizogenesis of Toona ciliata clone cutting orchard were studied, and the results were as fol ows: Rooting type included both cal us rooting and cortex rooting. About 17 in 22 of clones were dominated by cortex rooting, accounting for the 77% of clones. There were 5 clones which occurred with both cal us rooting and cortex rooting during rooting process. The rooting efficiency index (REI) showed a positive correlation with the rooting rate. Under natural tem-perature condition, keeping moisture and shading, we found that the highest survival rate occurred in early June, September, and October.
基金Supported by the National Key Technology R&D Program(2012BAD21B03)Specialized Research Fund for The Doctoral Program of Higher Education(20124404120008)~~
文摘[Objective] This study aimed to provide scientific basis for the early selec-tion and breeding of excellent Catalpa bungei clones. [Method] The Li-6400 portable photosynthesis system was used to analyze the photosynthetic characteristics of five Catalpa bungei clones (1-3, 1-4, 004-1, 015-1 and 7080). [Result] Al five Catalpa bungei clones had similar change trends of light response curves, but their maxi-mum net photosynthetic rates (Pmax) were in the order of 1-3>7080>015-1>004-1>1-4, showing that clone 1-3 and clone 7080 had strong light environmental adapt-ability with the light saturation points (LSP) of 1 147.97 μmol/m2·s and 1 196.31μmol/m2·s, respectively, while clone 1-4 had the narrowest range of adaptation to light. There were differences in the total photosynthetic amount per area among the five clones that clone 1-4 was the best of 433 974.24 μmol/m2, fol owed by clone 1-3 of 401 290.20 μmol/m2. The transpiration rates (Tr) and stomatal conductances (Cond) of the five clones presented the same change trend. And the diurnal varia-tion curves of net photosynthetic rate (Pn) of clone 1-3, 1-4 and 015-1 showed two typical peaks with obvious midday depression, while clone 004-1 and 7080 didn’t. [Concluson] Considering a variety of photosynthetic characteristics of indica-tors, photosynthetic capacity of clone 1-3 was the best among the five Catalpa bungei clones.
文摘Poplar is one of the dominant tree species for the establishment of fast growing plantations in Shandong Province. Eighteen poplar clones belonging to Populus aigeiros section were introduced from Italy, Turkey and domestic regions. Populus deltoides cv. 慙ux?I-69/55 (I-69), which was widely used in Shandong Province, China, was taken as control clone (I-69). Following a randomized complete block design, seedling test and controlled afforestation trials were carried out at Juxian County, Caoxian County and Laiyang City. The results showed that the poplar clone (Populus ?euramericana cv. ?02/74?, namely 102/74, performed well both in terms of adaptability and growth rate. The mean height of 13.9 m (H), diameter at breast height of 18.0 cm (DBH) and volume growth of 0.1445 m3 (V) were 2.2 %, 21.6% and 52.9 % higher than those of I-69 (CK), respectively, at the age of 5 years at three experimental sites. Moreover, the clone can be propagated easily and showed high resistance to poplar disease, pest as well as salinity and had longer growing period. Furthermore, wood basic density and fiber length of new poplar clone (102/74) were as same as I-69 (CK). It was concluded that the selected clone (102/74) was ideal for the estab-lishment of fast-growing poplar plantations, especially for the pulpwood plantations in Shandong Province.
文摘The wood samples of 9 triploid clones of Populus tomentosa Carr. taken from a 9 year old clonal test site were analyzed in order to investigate the genetic variation of wood properties, including air dried wood density and some mechanical properties. The results showed that significant or extremely significant difference in air dried wood density and the mechanical properties existed among the clones, this means these wood properties were under moderate or strong genetic controls and could be improved by genetic manipulations. The radial and vertical variation patterns of air dried wood density were also studied and the results were found to coordinate with other previous research results. The vertical variation patterns of most mechanical properties within the individual tree also conformed to the general wood theories except the modulus of elasticity and cross section hardness. Among the mechanical properties, modulus of elasticity (MOE) and tangent section hardness were under strong genetic control, with the clonal repeatabilities being 0 90 and 0 80, respectively. However, the clonal repeatabilities of other mechanical properties under study were a little lower than above two indexes. Genetic correlation analysis indicated that super clonal selection and breeding for veneer timber could be realized through indirect selection of wood density and form indexes.
基金Supported by National Natural Science Foundation (30070633 )National Science and Technology Supporting Project during the Eleventh Five-year Plan(2007BAD67B02)~~
文摘[Objective] The aim was to study the effects of drought stress on contents of endogenous hormones in leaves of different clones of Liriodendron chinense×L. tulipifera. Drought-resistant Liriodendron chinense×L. tulipifera clones NE25,NE78 and drought-sensitive Liriodendron chinense×L. tulipifera clones NE04,NE23 were selected as experimental materials to study the content changes of four kinds of endogenous hormones such as abscisic acid (ABA),indoleacetic acid (IAA),ribosylzeatin (ZR) and jasmonic acid (JA) in leaves of different clones under drought stress. [Result] Under drought stress,ABA was accumulated I leaves of different clones,however,the content changes in drought-resistant clones were not obvious; IAA content showed a decreasing trend,and the content changes n drought-resistant clones during later period of drought stress was decreased; JA content showed an increasing trend in leaves of drought-sensitive clones,indicating that drought-sensitive clones had to maintain higher contents of JA to resist drought stress. [Conclusion] The result of this study had provided scientific basis for the screening,planting and application of drougt-resistant clones of Liriodendron chinense×L. tulipifera.
基金This work was supported by the National Natural Science Foundation(61363017)of China.The author is Liu,D.S.and the website is https://isisn.nsfc.gov.cn.
文摘Reusing code fragments by copying and pasting them with or without minor adaptation is a common activity in software development.As a result,software systems often contain sections of code that are very similar,called code clones.Code clones are beneficial in reducing software development costs and development risks.However,recent studies have indicated some negative impacts as a result.In order to effectively manage and utilize the clones,we design an approach for recommending refactoring clones based on a Bayesian network.Firstly,clone codes are detected from the source code.Secondly,the clones that need to be refactored are identified,and the static and evolutions features are extracted to build the feature database.Finally,the Bayesian network classifier is used for training and evaluating the classification results.Based on more than 640 refactor examples of five open source software developed in C,we observe a considerable enhancement.The results show that the accuracy of the approach is larger than 90%.We believe our approach will provide a more accurate and reasonable code refactoring and maintenance advice for software developers.
文摘The oxygen evolution, thermal dissipation, and photochemical energy storage of three hybrid poplar clones, namely the triploid clone B342, the diploid clone B11 [(Populus alba×P. glandulosa)×(P.tomentosa×P.bolleana)], and the triploid clone B346 [(P.tomentosa×P. bolleana)×(P. alba×P.glandulosa)], under light stress were studied using photoacoustics. The oxygen evolution signal and photochemical energy storage varied negatively with the pretreatment_PFD (photon flux density), whereas the thermal signal varied positively with the pretreatment_PFD. Photochemical energy storage was reallocated to PSⅡ more than to PSⅠ, while the photochemical energy storage in PSⅠ was more stable than that in PSⅡ when subjected to light stress. The inhibitors streptomycin (SM), dithiothreitol (DTT) and sodium fluoride (NaF) could all affect the oxygen evolution signal. Clones B11 and B342 were more resistant to light stress than clone B346.
基金Supportod ty the State Key Basic Research Program Grant G1998051211 the Fund for Leading Specialty of Shanghai Metropolitan Bureau of Public Health.
文摘AIM: To establish clone cells with different metastatic potential for the study of metastasis-related mechanisms. METHODS: Cloning procedure was performed on parental hepatocellular carcinoma (HCC) cell line MHCC97, and biological characteristics of the target clones selected by in vivo screening were studied. RESULTS: Two clones with high (MHCC97-H) and low (MHCC97-L) metastatic potential were isolated from the parent cell line. Compared with MHCC97-L, MHCC97-H had smaller cell size (average cell diameter 43 microm vs 50 microm) and faster in vitro and in vivo growth rate (tumor cell doubling time was 34.2h vs 60.0h). The main ranges of chromosomes were 55-58 in MHCC97-H and 57-62 in MHCC97-L. Boyden chamber in vitro invasion assay demonstrated that the number of penetrating cells through the artificial basement membrane was (37.5 +/- 11.0) cells/field for MHCC97-H vs (17.7 +/- 6.3)/field for MHCC97-L. The proportions of cells in G0-G1 phase, S phase, and G2-M phase for MHCC97-H/MHCC97-L were 0.56/0.65, 0.28/0.25 and 0.16/0.10, respectively, as measured by flow cytometry. The serum AFP levels in nude mice 5wk after orthotopic implantation of tumor tissue were (246 +/- 66) microg.L(-1) for MHCC97-H and (91 +/- 66) microg.L(-1) for MHCC97-L. The pulmonary metastatic rate was 100% (10/10) vs 40% (4/10). CONCLUSION: Two clones of the same genetic background but with different biological behaviors were established, which could be valuable models for investigation on HCC metastasis.
文摘Mapping of low or single-copy sequences on plant chromosomes has proven difficult because of very low frequency of signal detection. Rice BAC library is being used widely in rice genome research due to its distinctive advantages over other library systems. In this study, two biotin-labeled rice BAC clones closely linked to a rice blast resistance, green leafhopper resistance and tungro spherical virus resistance gene,Pi-5(t), Glh, RTSV, werein situ hybridized to rice chromosomes. They were located on the long arm and short arm of chromosome 4 with FL value of 40%and 100%respectively. The frequency of signal detection reached 46.8%and 59.2%. The signal location were consistent with the selective marker on rice saturated molecular map. The results demonstrated the advantages to locate BAC clones to chromosomes byin situ hybridization and will facilitate the rice low or single-copy gene location by using the BAC library.
文摘Methamidophos was widely used a pesticide in northern China. The potential influences of methamidophos on soil fungal community in black soil were assessed by plate count, 28S rDNA-PCR-DGGE, and clone library analysis. Three methamidophos levels (50, 150, and 250 mg/kg) were tested in soil microcosms. Results from plate count during a 60-d microcosm experiment showed that high concentrations of methamidophos (250 mg/kg) could significantly stimulate fungal populations. DGGE (denaturing gradient gel electrophoresis) fingerprinting patterns showed a significant difference between the responses of culturable and total fungi communities under the stress of methamidophos. Shannon diversity indices calculated from DGGE profiles indicated that culturable fungi in all microcosms with methamidophos treatment increased after 1 week of incubation. However, the diversity indices of total fungi decreased in the first week, as compared to the stimulation of culturable fungi. At the 8th week, however, all the microcosms treated by methamidophos were similar to the control microcosms in community structure as suggested by the Shannon diversity indices for both culturable and total fungi. In contrast, after 1 week the fungal structure of culturable and unculturable both were disturbed to different extent under the stresses of methamidophos by clustering analysis. Clone sequencing analysis indicated the stimulation of pathogenic and unculturable fungal populations by methamidophos treatment, suggetsing potential risks of plant disease outbreak.