Somatic cell nuclear transfer(SCNT)has been successfully employed across various mammalian species,yet cloned animals consistently exhibit low pregnancy rates,primarily due to placental abnormalities such as hyperplas...Somatic cell nuclear transfer(SCNT)has been successfully employed across various mammalian species,yet cloned animals consistently exhibit low pregnancy rates,primarily due to placental abnormalities such as hyperplasia and hypertrophy.This study investigated the involvement of the Hippo signaling pathway in aberrant placentaldevelopmentinSCNT-inducedbovine pregnancies.SCNT-derived cattle exhibited placental hypertrophy,including enlarged abdominal circumference and altered placental cotyledon morphology.RNA sequencing analysis indicated significant dysregulation of Hippo signaling pathway genes in SCNT placentas.Coexpression of YAP1 and CCND1 was observed in cloned blastocysts,placental tissues,and bovine placental mesenchymal stem cells(bPMSCs).Manipulation of YAP1expression demonstrated the capacity to regulate bPMSC proliferation.Experimental assays confirmed the direct binding of YAP1 to CCND1,which subsequently promoted CCND1 expression in bPMSCs.Furthermore,inhibition of CDK6,a downstream target of CCND1,attenuated SCNT bPMSC proliferation.This study identified YAP1 as a key regulatory component within the Hippo signaling pathway that drives placental hyperplasia in cloned cattle through up-regulation of CCND1-CDK6 expression,facilitating cell cycle progression.These findings offer potential avenues for enhancing cloning efficiency,with implications for evolutionary biology and the conservation of valuable germplasm resources.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
[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
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
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＆gt;7080＆gt;015-1＆gt;004-1＆gt;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＆#183;s and 1 196.31μmol/m2＆#183;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
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
基金supported by the National Natural Science Foundation of China (32060755)Natural Science Foundation of Inner Mongolia (2024MS03001)+7 种基金Inner Mongolia Autonomous Region Open Competition Projects (2022JBGS0018)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region (NJYT23090)Inner Mongolia Autonomous Region Science and Technology Leading Team (2022LJRC0006)Inner Mongolia Autonomous Region Science and Technology Major Project (2021ZD0009)Major Agricultural Science and Technology Project of the Ministry of Agriculture and Rural Affairs (NK2022130203)Central Government Guides Local Science and Technology Development Funds (2022ZY0212)Inner Mongolia Autonomous Region High-level Talent Support ProgramInner Mongolia University Chief Scientist Program。
文摘Somatic cell nuclear transfer(SCNT)has been successfully employed across various mammalian species,yet cloned animals consistently exhibit low pregnancy rates,primarily due to placental abnormalities such as hyperplasia and hypertrophy.This study investigated the involvement of the Hippo signaling pathway in aberrant placentaldevelopmentinSCNT-inducedbovine pregnancies.SCNT-derived cattle exhibited placental hypertrophy,including enlarged abdominal circumference and altered placental cotyledon morphology.RNA sequencing analysis indicated significant dysregulation of Hippo signaling pathway genes in SCNT placentas.Coexpression of YAP1 and CCND1 was observed in cloned blastocysts,placental tissues,and bovine placental mesenchymal stem cells(bPMSCs).Manipulation of YAP1expression demonstrated the capacity to regulate bPMSC proliferation.Experimental assays confirmed the direct binding of YAP1 to CCND1,which subsequently promoted CCND1 expression in bPMSCs.Furthermore,inhibition of CDK6,a downstream target of CCND1,attenuated SCNT bPMSC proliferation.This study identified YAP1 as a key regulatory component within the Hippo signaling pathway that drives placental hyperplasia in cloned cattle through up-regulation of CCND1-CDK6 expression,facilitating cell cycle progression.These findings offer potential avenues for enhancing cloning efficiency,with implications for evolutionary biology and the conservation of valuable germplasm resources.
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 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 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 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＆gt;7080＆gt;015-1＆gt;004-1＆gt;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＆#183;s and 1 196.31μmol/m2＆#183;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.
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.
