Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegr...Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.展开更多
[Objective]The aim was to commercialize micropropagation of pistachio and provide good foundations for varieties improvement. [Method]The seeds and stem-segments were used as explants in the tissue culture of Pistacia...[Objective]The aim was to commercialize micropropagation of pistachio and provide good foundations for varieties improvement. [Method]The seeds and stem-segments were used as explants in the tissue culture of Pistacia vera 'Kerman',tissue culture condition and medium and transplant matrix were researched for micropropagation of pistachio,[Result]Mediums of 1/2DKW and 1/2DKW+3.00 mg/L of 6-BA +0.05 mg/L of NAA were suitable medium for seed germination and axillary bud induction of pistachio; Proliferation coefficient was 3.6 on the medium of 1/2DKW +4.00 mg/L of 6-BA + 0.05 mg/L of IBA; Rooting rate was up to 75% on the medium of 1/2DKW + 5.00 mg/L of IBA + 1.00 mg/L of NAA; The suitable transplantation matrix was 3/4 sand + 1/4 vermiculite,and survival rate of plant with root was above 79%. [Conclusion]The pistachio (Kerman) tissue culture technology system was established.展开更多
[Objective] The aim was to carry out study on tissue culture of Lespedeza cyrtobotrya. [Method] The seeds of L. cyrtobotrya were used as materials to study on its tissue culture. [Result] The best sterilization time t...[Objective] The aim was to carry out study on tissue culture of Lespedeza cyrtobotrya. [Method] The seeds of L. cyrtobotrya were used as materials to study on its tissue culture. [Result] The best sterilization time to L. cyrtobotrya seeds was 8 min with 2.1% NaClO,in which shooting percent reached 37.8% and no polluted situations occurred. In the primary culture with the MS as basal medium,the concentration of 6-BA showed a significant effect on the index of buds differentiation,the optimum differentiation culture medium was MS+BA 1.0 mg/L+NAA 0.1 mg/L+2,4-D 0.01 mg/L,on which the index of generation could reach 6.69. The optimum subculture medium was MS+6-BA 1.0 mg/L+2,4-D 0.05 mg/L. The plants can generate the highest roots and rooting percent with IBA 0.50 mg/L. [Conclusion] This study had provided theoretical basis for genetic improvement of L. cyrtobotrya.展开更多
[Objective]This study was to optimize callus induction medium for Schisandga chinensis Baill.[Method]Using callus induction rate as an indicator,uniform design was employed to optimize hormone combination at poly-fact...[Objective]This study was to optimize callus induction medium for Schisandga chinensis Baill.[Method]Using callus induction rate as an indicator,uniform design was employed to optimize hormone combination at poly-factors and poly-levels for callus induction from Schisandga chinensis Baill.[Results]Optimal hormone combinations depended on different explants:optimum medium for both tender leaf and petiole was MS +3 mg/L 6-BA,for stem segment was MS +3 mg/L 6-BA +0.6 mg/L NAA.[Conclusion]Uniform design is a time-saving and convenient method for the optimum medium for callus and yields a higher callus induction rate.展开更多
A Cu-25Cr alloy prepared by vacuum induction melting method was treated by the high current pulsed electron beam (HCPEB) with pulse numbers ranging from 1 to 100. Surface morphologies and microstructures of the allo...A Cu-25Cr alloy prepared by vacuum induction melting method was treated by the high current pulsed electron beam (HCPEB) with pulse numbers ranging from 1 to 100. Surface morphologies and microstructures of the alloy before and after the treatment were investigated by scanning electron microscopy and X-ray diffraction. The results show that significant surface modification can be induced by HCPEB with the pulse number reaching 10. Craters with typical morphologies on the Cu-25Cr alloy surface are formed due to the dynamic thermal field induced by the HCPEB. Micro-cracks, as a unique feature, are well revealed in the irradiated Cu-25Cr specimens and attributed to quasi-static thermal stresses accumulated along the specimen surface. The amount of cracks is found to increase with the pulse number and a preference of these cracks to Cr phases rather than Cu phases is also noted. Another characteristic produced by the HCPEB is the fine Cr spheroids, which are determined to be due to occurrence of liquid phase separation in the Cu-25Cr alloy. In addition, an examination on surface roughness of all specimens reveals that more pulses will produce a roughened surface, as a result of compromising the above features.展开更多
[Objective] The aim of this article is to establish a cell suspension culture system for eggplant. [Method] Using orthogonal design, appropriate media were screened for callus induction, subculture and cell suspension...[Objective] The aim of this article is to establish a cell suspension culture system for eggplant. [Method] Using orthogonal design, appropriate media were screened for callus induction, subculture and cell suspension culture. [Result] The appropriate medium for callus induction was MS supplemented with 0.2 mg/L 6-BA and 0.2 mg/L NAA; the appropriate subculture medium was MS supplemented with0.2 mg/L 6-BA, 0.2 mg/L NAA, and 0.1 mg/L KT; the suitable medium for cell suspension culture was liquid MS medium supplemented with 0.4 mg/L NAA and 0.2mg/L. Cell growth curve was similar to "S" shape in the above suspension medium.The cell growth included four phases, the initial phase(1-3 d), the logarithmic phase(3-7 d), the steady phase(7-8 d), and the decline phase(8-11 d). With the increasing culture time, the number of suspension cells increased, and it reached the maximum value at the 7thd, about 3.8 ×105cells/ml. Then the number of cells began to decline rapidly. The cell vigor was the highest at the initial phase. Suspension cells grew best in the liquid MS medium supplemented with NAA(0.4 mg/L)and 6-BA(0.2 mg/L). The mitotic index reached the maximum, about 4.1% in the above medium, which suggested that this medium was suitable for cell suspension culture of eggplant. [Conclusion] Cell suspension culture system of eggplant provides a significant method for eggplant biotechnology. Genetic transformation and mutants screening can be carried out with this system.展开更多
Soybean somatic cell could induce the development of embryoid which was similar to embryo morphologically and structurally. Somatic embryogenesis system of soybean was used to conduct genetic transformation of soybean...Soybean somatic cell could induce the development of embryoid which was similar to embryo morphologically and structurally. Somatic embryogenesis system of soybean was used to conduct genetic transformation of soybean because of its several advantages such as higher transformational efficiency, beetter synchronism and fewer plant chimeras among transgenic plants. After infected with agrobacterium tumefaciens,the initiation, differentiation and development of young cotyledon embryogenic cell of soybean which was cultured on selective culture medium with kanamycin were investigated through histological study. The result showed that somatic embryo was differentiated in non-bud differentiation way. The embryogenic cells were differentiated from epidermis of explant or cells in 1 layer or 2 layers, with the division of embryogenic cells and degradation and disorganization of surrounding cells, the embryogenic cells would form embryoid with analogous suspensor structure. Later, globular embryoid would extrude from epidermis then developed into heart-shape embryo. The experiment was expected to provide theoretical reference for the construction of high transformational system of using plant somatic embryogenesis induced by young cotyledon of soybean.展开更多
The microstructure, phase composition and cold shut defect of thick titanium alloy electron beam welded joint were studied. The results showed that the microstructure of weld zone was composed of α′ phase; the heat ...The microstructure, phase composition and cold shut defect of thick titanium alloy electron beam welded joint were studied. The results showed that the microstructure of weld zone was composed of α′ phase; the heat affected zone was divided into fine-grained zone and coarse-grained zone, the microstructure of fine-grained zone was primary α phase + β phase + equiaxed α phase, and the microstructure of coarse-grained zone was primary α phase + acicular α′ phase; the microstructure of base metal zone basically consisted of primary α phase, and a small amount of residual β phase sprinkled. The forming. reason of cold shut was analyzed, and the precaution of cold shut was proposed.展开更多
The effect of arc-ultrasound on microstructures and mechanical properties of SiCp/6061A1 MMCs joints produced by arc-ultrasound plasma arc "in-situ" alloy-welding with different excitation frequencies was investigat...The effect of arc-ultrasound on microstructures and mechanical properties of SiCp/6061A1 MMCs joints produced by arc-ultrasound plasma arc "in-situ" alloy-welding with different excitation frequencies was investigated, in which argon-nitrogen mixture was used as plasma gas, Ti wire as filler and the arc-ultrasound was produced by modulating the plasma arc with high frequency. The results show that arc-ultrasound could refine the new reinforced composites such as TiC, TiN significantly, and improve their distribution greatly. And new phase A13Ti becomes finer and less. The test results of mechanical properties indicate that the maximum tensile strength of welded joints is gained when the excitation frequency is 50 kHz, and the maximum is 225 MPa, raising by about 7% comoared with conventional nlasma arc welding (PAW) (20q MPa).展开更多
[ Objective] Through inductive culture, emodin and chrysophanol contents in cassia seed were increased. [ Method ] MS culture medium was used to bourgeon seedlings of cassia seed and to induce cotyledon callus of cass...[ Objective] Through inductive culture, emodin and chrysophanol contents in cassia seed were increased. [ Method ] MS culture medium was used to bourgeon seedlings of cassia seed and to induce cotyledon callus of cassia seed while HPLC method was adopted to determine emodin and ehrysophanol eontents.[ Result] Emedin and chrysophanol contents in cotyledon callus were 0. 099% and 0. 312%, respectively, while they were 0.029% and 0. 190% respectively in cassia seed. [ Conclusion] The method of inducing cotyledon callus was helpful for increasing emodin coment in cassia seed.展开更多
A fine-grained TiAl alloy with the composition of Ti-43Al-9V was prepared by mechanical milling and spark plasma sintering(SPS).The relationship among sintering temperature,microstructure and mechanical properties w...A fine-grained TiAl alloy with the composition of Ti-43Al-9V was prepared by mechanical milling and spark plasma sintering(SPS).The relationship among sintering temperature,microstructure and mechanical properties was studied.The results show that the morphology of mechanical milling powder is regular with size in a range of 5-30 μm.Main phases of γ-TiAl,α2-Ti3Al and few B2 phase are observed in the SPS bulk samples.For samples sintered at 1150 °C,equiaxed crystal grain microstructure is achieved with size in a range of 300 nm-1 μm.With increasing SPS temperature to 1250 °C,the size of equiaxed crystal grains obviously increases,the microhardness decreases from HV592 to HV535,and the bending strength decreases from 605 to 219 MPa.Meantime,the compression fracture strength also decreases from 2601 to 1905 MPa,and the strain compression decreases from 28.95% to 12.09%.展开更多
基金Supported by National Natural Science Foundation of China(30471274)~~
文摘Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.
基金Supported by Beijing Natural Science Foundation (6072005)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality(PXM2009-014207-076874)~~
文摘[Objective]The aim was to commercialize micropropagation of pistachio and provide good foundations for varieties improvement. [Method]The seeds and stem-segments were used as explants in the tissue culture of Pistacia vera 'Kerman',tissue culture condition and medium and transplant matrix were researched for micropropagation of pistachio,[Result]Mediums of 1/2DKW and 1/2DKW+3.00 mg/L of 6-BA +0.05 mg/L of NAA were suitable medium for seed germination and axillary bud induction of pistachio; Proliferation coefficient was 3.6 on the medium of 1/2DKW +4.00 mg/L of 6-BA + 0.05 mg/L of IBA; Rooting rate was up to 75% on the medium of 1/2DKW + 5.00 mg/L of IBA + 1.00 mg/L of NAA; The suitable transplantation matrix was 3/4 sand + 1/4 vermiculite,and survival rate of plant with root was above 79%. [Conclusion]The pistachio (Kerman) tissue culture technology system was established.
基金Supported by National High Technology Research and Development Program of China (2002AA241111 )Introduction of International Advanced Agricultural Science and Technology Program " 948 "(2001-25)~~
文摘[Objective] The aim was to carry out study on tissue culture of Lespedeza cyrtobotrya. [Method] The seeds of L. cyrtobotrya were used as materials to study on its tissue culture. [Result] The best sterilization time to L. cyrtobotrya seeds was 8 min with 2.1% NaClO,in which shooting percent reached 37.8% and no polluted situations occurred. In the primary culture with the MS as basal medium,the concentration of 6-BA showed a significant effect on the index of buds differentiation,the optimum differentiation culture medium was MS+BA 1.0 mg/L+NAA 0.1 mg/L+2,4-D 0.01 mg/L,on which the index of generation could reach 6.69. The optimum subculture medium was MS+6-BA 1.0 mg/L+2,4-D 0.05 mg/L. The plants can generate the highest roots and rooting percent with IBA 0.50 mg/L. [Conclusion] This study had provided theoretical basis for genetic improvement of L. cyrtobotrya.
基金Supported by International Collaboration Research Program~~
文摘[Objective]This study was to optimize callus induction medium for Schisandga chinensis Baill.[Method]Using callus induction rate as an indicator,uniform design was employed to optimize hormone combination at poly-factors and poly-levels for callus induction from Schisandga chinensis Baill.[Results]Optimal hormone combinations depended on different explants:optimum medium for both tender leaf and petiole was MS +3 mg/L 6-BA,for stem segment was MS +3 mg/L 6-BA +0.6 mg/L NAA.[Conclusion]Uniform design is a time-saving and convenient method for the optimum medium for callus and yields a higher callus induction rate.
基金Projects(51101177,51401040,51171146,51171216) supported by the National Natural Science Foundation of ChinaProject(CSTC2012JJA245) supported by the Natural Science Foundation of Chongqing,China
文摘A Cu-25Cr alloy prepared by vacuum induction melting method was treated by the high current pulsed electron beam (HCPEB) with pulse numbers ranging from 1 to 100. Surface morphologies and microstructures of the alloy before and after the treatment were investigated by scanning electron microscopy and X-ray diffraction. The results show that significant surface modification can be induced by HCPEB with the pulse number reaching 10. Craters with typical morphologies on the Cu-25Cr alloy surface are formed due to the dynamic thermal field induced by the HCPEB. Micro-cracks, as a unique feature, are well revealed in the irradiated Cu-25Cr specimens and attributed to quasi-static thermal stresses accumulated along the specimen surface. The amount of cracks is found to increase with the pulse number and a preference of these cracks to Cr phases rather than Cu phases is also noted. Another characteristic produced by the HCPEB is the fine Cr spheroids, which are determined to be due to occurrence of liquid phase separation in the Cu-25Cr alloy. In addition, an examination on surface roughness of all specimens reveals that more pulses will produce a roughened surface, as a result of compromising the above features.
基金Supported by the National Key Technology R&D Program of China(2011BAD12B03)the National Natural Science Foundation of China(30700002,31101536)~~
文摘[Objective] The aim of this article is to establish a cell suspension culture system for eggplant. [Method] Using orthogonal design, appropriate media were screened for callus induction, subculture and cell suspension culture. [Result] The appropriate medium for callus induction was MS supplemented with 0.2 mg/L 6-BA and 0.2 mg/L NAA; the appropriate subculture medium was MS supplemented with0.2 mg/L 6-BA, 0.2 mg/L NAA, and 0.1 mg/L KT; the suitable medium for cell suspension culture was liquid MS medium supplemented with 0.4 mg/L NAA and 0.2mg/L. Cell growth curve was similar to "S" shape in the above suspension medium.The cell growth included four phases, the initial phase(1-3 d), the logarithmic phase(3-7 d), the steady phase(7-8 d), and the decline phase(8-11 d). With the increasing culture time, the number of suspension cells increased, and it reached the maximum value at the 7thd, about 3.8 ×105cells/ml. Then the number of cells began to decline rapidly. The cell vigor was the highest at the initial phase. Suspension cells grew best in the liquid MS medium supplemented with NAA(0.4 mg/L)and 6-BA(0.2 mg/L). The mitotic index reached the maximum, about 4.1% in the above medium, which suggested that this medium was suitable for cell suspension culture of eggplant. [Conclusion] Cell suspension culture system of eggplant provides a significant method for eggplant biotechnology. Genetic transformation and mutants screening can be carried out with this system.
基金the National Natural Science Foundation of China (C02020504)the Scientific and Techrological Developing Scheme of Jilin Province (20050217-2+1 种基金20060204)the national 863 project (2006AA100104-17)~~
文摘Soybean somatic cell could induce the development of embryoid which was similar to embryo morphologically and structurally. Somatic embryogenesis system of soybean was used to conduct genetic transformation of soybean because of its several advantages such as higher transformational efficiency, beetter synchronism and fewer plant chimeras among transgenic plants. After infected with agrobacterium tumefaciens,the initiation, differentiation and development of young cotyledon embryogenic cell of soybean which was cultured on selective culture medium with kanamycin were investigated through histological study. The result showed that somatic embryo was differentiated in non-bud differentiation way. The embryogenic cells were differentiated from epidermis of explant or cells in 1 layer or 2 layers, with the division of embryogenic cells and degradation and disorganization of surrounding cells, the embryogenic cells would form embryoid with analogous suspensor structure. Later, globular embryoid would extrude from epidermis then developed into heart-shape embryo. The experiment was expected to provide theoretical reference for the construction of high transformational system of using plant somatic embryogenesis induced by young cotyledon of soybean.
基金Project (2010CB731704) supported by the National Basic Research Program of China
文摘The microstructure, phase composition and cold shut defect of thick titanium alloy electron beam welded joint were studied. The results showed that the microstructure of weld zone was composed of α′ phase; the heat affected zone was divided into fine-grained zone and coarse-grained zone, the microstructure of fine-grained zone was primary α phase + β phase + equiaxed α phase, and the microstructure of coarse-grained zone was primary α phase + acicular α′ phase; the microstructure of base metal zone basically consisted of primary α phase, and a small amount of residual β phase sprinkled. The forming. reason of cold shut was analyzed, and the precaution of cold shut was proposed.
基金Project (09003)supported by the Open Research Fund of State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, ChinaProject (JSAWT-07-04 ) supported by Provincial Key Research Fund of Advanced Welding Technology, Jiangsu University of Science and Technology, China
文摘The effect of arc-ultrasound on microstructures and mechanical properties of SiCp/6061A1 MMCs joints produced by arc-ultrasound plasma arc "in-situ" alloy-welding with different excitation frequencies was investigated, in which argon-nitrogen mixture was used as plasma gas, Ti wire as filler and the arc-ultrasound was produced by modulating the plasma arc with high frequency. The results show that arc-ultrasound could refine the new reinforced composites such as TiC, TiN significantly, and improve their distribution greatly. And new phase A13Ti becomes finer and less. The test results of mechanical properties indicate that the maximum tensile strength of welded joints is gained when the excitation frequency is 50 kHz, and the maximum is 225 MPa, raising by about 7% comoared with conventional nlasma arc welding (PAW) (20q MPa).
基金Science and Technology Development Funds of Southwest Jiaotong University (20070013)~~
文摘[ Objective] Through inductive culture, emodin and chrysophanol contents in cassia seed were increased. [ Method ] MS culture medium was used to bourgeon seedlings of cassia seed and to induce cotyledon callus of cassia seed while HPLC method was adopted to determine emodin and ehrysophanol eontents.[ Result] Emedin and chrysophanol contents in cotyledon callus were 0. 099% and 0. 312%, respectively, while they were 0.029% and 0. 190% respectively in cassia seed. [ Conclusion] The method of inducing cotyledon callus was helpful for increasing emodin coment in cassia seed.
基金Project (51001040) supported by the National Natural Science Foundation of China
文摘A fine-grained TiAl alloy with the composition of Ti-43Al-9V was prepared by mechanical milling and spark plasma sintering(SPS).The relationship among sintering temperature,microstructure and mechanical properties was studied.The results show that the morphology of mechanical milling powder is regular with size in a range of 5-30 μm.Main phases of γ-TiAl,α2-Ti3Al and few B2 phase are observed in the SPS bulk samples.For samples sintered at 1150 °C,equiaxed crystal grain microstructure is achieved with size in a range of 300 nm-1 μm.With increasing SPS temperature to 1250 °C,the size of equiaxed crystal grains obviously increases,the microhardness decreases from HV592 to HV535,and the bending strength decreases from 605 to 219 MPa.Meantime,the compression fracture strength also decreases from 2601 to 1905 MPa,and the strain compression decreases from 28.95% to 12.09%.