The criticality of transformers and reactors in the power transmission network and the paramount importance of ensuring their reliability through maintenance of the insulating oil is known. This paper presents a compr...The criticality of transformers and reactors in the power transmission network and the paramount importance of ensuring their reliability through maintenance of the insulating oil is known. This paper presents a comprehensive examination of the efficacy and economic viability of a dielectric oil regeneration system, as implemented by the Transmission System Maintenance Department (TSMD) of the Independent Power Transmission Operator (IPTO), Greece’s sole transmission operator. Through a detailed chemical analysis and performance evaluation, we assess the impact of the regeneration system on treated insulating oil quality over multiple cycles. The study reveals that the electrical properties of the insulating oil are fully restored after regeneration, negating the need to fully replace it, while the investment becomes cost-neutral within weeks from the commissioning of the regeneration system. This economic analysis, coupled with the system’s environmental benefits of reducing waste oil generation, positions the dielectric oil regeneration system as a compelling solution for the maintenance of power transmission assets.展开更多
We used the cotyledons and cotyledonary nodes of Toona ciliata(Chinese mahogany)as explants to examine callus and adventitious shoot induction when exposed to different ratios of hormones.We also investigated the effe...We used the cotyledons and cotyledonary nodes of Toona ciliata(Chinese mahogany)as explants to examine callus and adventitious shoot induction when exposed to different ratios of hormones.We also investigated the effects of seedling age,inoculation method,and genotype on the efficient regeneration of T.ciliata.The results showed that different genotypes exhibited significantly different callus induction efficiency.The cotyledons and cotyledonary nodes of 20-day seedlings inoculated onto MS medium with 0.5 mg/L 6-benzylaminopurine(6-BA),0.5 mg/L kinetin(KT)and 0.05 mg/L 1-naphthylacetic acid(NAA)achieved a greater regeneration rate than did other concentrations of cytokinin and auxin.The numbers of shoots per cotyledon and cotyledonary node explant were 7.33 and 6.67.The optimal inoculation method for cotyledons was that the distal end of the explants was placed in contact with the medium.The optimal adventitious shoot differentiation medium for cotyledon explants was MS medium containing 0.3 mg/L 6-BA and 0.2 mg/L NAA,producing a 3.4 cm height of shoot on average.This study established an efficient regeneration system for T.ciliata with cotyledons and cotyledonary nodes as explants.展开更多
[Objectives]This study was conducted to establish a tissue culture regeneration system in Bama hemp(Cannabis sativa L.).[Methods]Using hemp seeds as explants,a regeneration system was established through explant steri...[Objectives]This study was conducted to establish a tissue culture regeneration system in Bama hemp(Cannabis sativa L.).[Methods]Using hemp seeds as explants,a regeneration system was established through explant sterilization,callus induction,callus differentiation,and rooting culture.[Results]The results showed that the best sterilization effect was achieved when sterilizing with 75%ethanol for 30 s,followed by 0.1%HgCl 2 solution for 9 min,with a contamination rate as low as 11.4%.In presence of 3 mg/L 2,4-D and 0.1 mg/L6-BA,the callus induction effect from hemp seeds was better.The formula for better differentiation of callus was MS+2.0 mg/L 6-BA+0.2 mg/L NAA.IBA had a promoting effect on the rooting of hemp aseptic plantlets.The highest rooting rate reached 80%when MS+0.3 mg/L IBA were used.[Conclusions]This study established a hemp seed regeneration system to provide technical support for the conservation and breeding of hemp germplasm resources.展开更多
[Objectives]To study the culture of callus produced by the leaves of the ethnic medicine‘E Se’,the induction of adventitious buds and the regeneration system of tissue culture seedlings.[Methods]Multi-factor orthogo...[Objectives]To study the culture of callus produced by the leaves of the ethnic medicine‘E Se’,the induction of adventitious buds and the regeneration system of tissue culture seedlings.[Methods]Multi-factor orthogonal experiment was used to design and analyze.[Results]The best medium for callus induction was MS+2.0 mg/L 6-BA+0.1 mg/L 2,4-D.By comparing the effects of cytokinin 6-BA,KT and TDZ on induction of adventitious bud differentiation,it was found that the optimum medium for adventitious bud regeneration was MS+0.5 mg/L 6-BA+0.5 mg/L KT+0.15 mg/L IBA.Finally,adding 0.2 mg/L IBA(0.1 or 0.2 mg/L)to MS medium could effectively make regenerated seedlings produce roots,and the efficiency was more than 70%.[Conclusions]It laid a foundation for the large-scale cultivation of the seedlings of the ethnic medicine‘E Se’and the promotion of their artificial cultivation.展开更多
Shoot meristems used for the study were exercised from the in vitro regenerated shoots cultured on MS medium supplemented with 0.5 mg/L of BAP for multiplication. The sensitivity of the in vitro regenerated was studie...Shoot meristems used for the study were exercised from the in vitro regenerated shoots cultured on MS medium supplemented with 0.5 mg/L of BAP for multiplication. The sensitivity of the in vitro regenerated was studied using shoot meristems of 0.5 cm. Shoot meristems were cultured on medium containing 10-100 mg/l kanamycin to determine the concentration that was lethal for multiple shoot induction and root induction. The response of shoot multiplication decreased (66.2%-6.2%) as the concentration of kanamycin increased (10.0-70.0 mg/L) with complete inhibition of shoot proliferation at 100 mg/L kanamycin. The rooting phase was very sensitive to kanamycin compared to shoot multiplication. The percentage of shoots that rooted decreased (53.8%-4.8%) with increase in the concentration of kanamycin (10.0-70.0 mg/l) on IBA and 2,4-D supplemented medium. For transformation studies, the shoot tips that were infected with Agrobacterium strain were placed on selection medium containing MS medium with 0.5 mg/L BAP and 100 mg/L kanamycin and scored for the putative transformed shoots. An average of 62.2% of shoot tips developed shoot buds from the base and the shoots reached a length of 0.5-1.0 cm at the end of 30 days of culture on the selective medium in comparison to control which showed no response. An average of 66.7% of the regenerated plants showed GUS expression on selection medium where 43.2% and 65% of GUS expression was recorded in the leaves and callus. Leaves and callus induced from the controls did not show GUS activity. Stable integration of nptII gene with the genomic DNA from these transformed plants was confirmed through PCR analysis. Our result presents an efficient regeneration system using in vitro derived shoot meristems for Agrobacterium mediated gene transfer.展开更多
Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration.Genetic engineering technology has been successfully used in many plant species,but it is limited in Hydrangea.Here we establish...Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration.Genetic engineering technology has been successfully used in many plant species,but it is limited in Hydrangea.Here we established an efficient regeneration system by using stem segments as explants for the first time.In our study,the plant growth regulators(PGRs)were evaluated at the different regeneration processes,including axillary shoots regeneration and root induction.We found that the optimal concentration for axillary buds’induction was 2.0 mgL^(-1)6-BA and 0.5 mgL^(-1)1 IAA,its highest induction rate was 70%.Moreover,the highest axillary shoots proliferation coefficient was 10.7 on the Murashige and Skoog(MS)medium with 2.0 mgL^(-1)6-benzyladenine(BA),0.2 mgL^(-1)indole-3-butyric acid(IBA),and 1.0 mgL^(-1)gibberellin A3(GA3).The highest frequency of root induction was 80.0±0.06%by culturing the elongated shoots in 1/2 MS medium containing 0.1 mgL^(-1)IBA.In summary,our study will provide an effective technology for large-scale propagation and important pathway for promoting the popularization and application of Hydrangea bretschneideri Dipp.展开更多
Though the traditional energy regeneration system(ERS) which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and...Though the traditional energy regeneration system(ERS) which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.展开更多
Citrus reticulata (Mandarin Orange), commonly known as “Sweet Orange”, is one of the most difficult plants to improve through traditional breeding approaches as it poses various biological limitations that greatly h...Citrus reticulata (Mandarin Orange), commonly known as “Sweet Orange”, is one of the most difficult plants to improve through traditional breeding approaches as it poses various biological limitations that greatly hinder the cultivar improvement. In the present study, using the fresh seed of native orange as explant, an efficient, reproducible, regeneration method was developed through in vitro organogenesis. Mature, healthy and dehusked seeds were treated with Murashige and Skoog, (MS) media containing 3% sucrose, 0.7% agar supplemented with different concentrations and combinations of phytohormones. The highest calli initiation (93.3% ± 0.5%) responses were observed on MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) at 3.0 mg/L followed by 2,4-D at 3.5 mg/L (86.7% ± 1.75%) in this experiment. Maximum shoot regeneration (86.7% ± 3.35%) responses were reported using MS medium supplemented with the combination of 6-benzylaminopurine (BAP) at 3.0 mg/L and 1-naphthaleneacetic acid (NAA) at 2.0 mg/L. MS medium supplemented with NAA at 1.0 mg/L showed the best rooting (80% ± 2.89%) response in comparison to (70% ± 5.20%) indole-3-butyric acid (IBA) at 1.0 mg/L. The regenerated plantlets were acclimatized in pots containing sterile garden soil mixture to examine their response in natural conditions.展开更多
Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign gen...Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign genes into wheat. By using the mature embryos derived from 20 different wheat lines including Shi 4185, Yumai 66, Lunxuan 987, CB037, Yangmai 6, Xinchun 9, Bobwhite, Han 6172, Zheng 9023, Jimai 20, Ningchun 4, and Jing 411, the effects of some factors including inoculation methods, initiating culture media, organic additives, antioxidants, and auxins on the regeneration from the explants were evaluated. The results indicated that the scraping embryo culture was better than the whole embryo culture, the Aa medium was better than the SD2 medium and dicamba was better than 2,4-D in increasing the regeneration frequency. An Adi medium was established in this study by adding silver nitrate, cysteine, ascorbic acid, dicamba, glutamine into the Aa medium at the concentration of 4 , 40, 100, 2, and 5 mg L-1, respectively. By using the Adi medium and the scraping technique, the regeneration frequencies of the mature embryos of CB037, Lunxuan 987, Han 6172, Yangmai 6, Bobwhite, Zheng 9023, Shi 4185, and Jimai 20 became 85.6, 60.1, 46.0, 42.1, 42.0, 34.0, 33.0, and 32.0%, respectively, which were about 5-8 times higher than that obtained from the conventional culture mediums and techniques. This novel regeneration system could be helpful in wheat transformation.展开更多
In the protocol of wheat transformation, to use elite wheat cultivars as exogenous gene recipients can speed up the process of commercial field applications of transgenic wheat. However, it is necessary to screen whea...In the protocol of wheat transformation, to use elite wheat cultivars as exogenous gene recipients can speed up the process of commercial field applications of transgenic wheat. However, it is necessary to screen wheat cultivars with good tissue culture response (TCR) continuously from plenty of elite wheat cultivars released for wheat transformation, and it is also important to find a plant regeneration system that is suitable for these cultivars. So, the TCR of mature and immature embryos of six wheat cultivars Chuannong 11 (CN11), Chuannong12 (CN12), Chuannong17 (CN17), Chuannong18 (CN18), Chuannong19 (CN19), and Chuannong21 (CN21), which possess superior agronomic traits, were investigated by using a good TCR wheat cultivar Bobwhite as control. The results indicated that only the immature and mature embryos of CN12, CN17, and CN18 exhibited good TCR compared with Bobwhite. No significant differences were observed between embryos of Bobwhite and of the three cultivars in TCR. Mature embryo-derived calli of CN12 were used as explants for transformation by particle bombardment of SAMDC gene. Seven transformants were obtained and the efficiency was 2.3%. This research supplies three new elite recipient cultivars for wheat transformation. The wheat plant regeneration system used in this research is different from those successful ones reported previously and it could be a reference for other wheat genotypes. Furthermore, Bobwhite and the three wheat cultivars were proved to be 1RS/1BL translocation, by methods of A-PAGE, C- banding, and genomic in situ hybridization (GISH). These results imply that probably there is some relationship between 1RS/1BL translocation and TCR of wheat embryos. So this research gives us a hint that we should pay more attention to the 1RS/1BL translocations when we screen the wheat cultivars with good TCR and also that the mechanism of the effect of 1RS/ 1BL translocation on TCR is worthy of being investigated.展开更多
Populus species are important resources for industry and in scientific study on biological and agricultural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar(Populus ciliata...Populus species are important resources for industry and in scientific study on biological and agricultural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar(Populus ciliata wall. ex Royle). The effect of TDZ alone and in combination with adenine and NAA was studied on the regeneration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glasshouses. After surface sterilization the explants were cultured on shoot induction medium. High percentage shoot regeneration(86 %) was recorded on MS medium supplemented with 0.004 mg L^-1TDZ and 79.7 mg L^-1adenine. The regenerated shoots for elongation and multiplication were transferred to MS + 0.5 mg L^-1BAP + 0.2 mg L^-1IAA +0.3 mg L-1GA3. Root regeneration from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L^-1IBA. Himalayan poplar plantlets could be produced within2 months after acclimatization in a sterile mixture of sand and soil. We developed a high efficiency plant regeneration protocol from petiole explants of P. ciliata.展开更多
A reliable system was developed for regeneration from mature embryos derived from callus of four maize inbred lines (Liao 7980,Dan 9818,Dan 340,and Dan 5026). The protocol was mainly based on a series of experiments i...A reliable system was developed for regeneration from mature embryos derived from callus of four maize inbred lines (Liao 7980,Dan 9818,Dan 340,and Dan 5026). The protocol was mainly based on a series of experiments involving the composition of culture medium. We found that 9 μM 2,4-dichlorophenoxyacetic acid in MS medium was optimum for the induction of callus. The induction frequency of primary calli was over 85% for four inbred lines tested. The addition of L-proline (12 mM) in subculture medium significantly promoted the formation of embryogenic callus but it did not significantly enhance growth rate of callus. Efficient shoot regeneration was obtained on regeneration medium containing 2.22 μM 6-benzylaminopurine in combinations with 4.64 μM Kinetin. Regenerated shoots were rooted on half-strength MS medium containing 2.85 μM indole-3-butyric acid. This plant regeneration system provides a foundation for genetic transformation of maize.展开更多
[Objective] This study aimed to establish in vitro regeneration system for Piper methysticum. [Method] With tender kava leaves and stems with bud as explants, different hormone combinations were added into basic mediu...[Objective] This study aimed to establish in vitro regeneration system for Piper methysticum. [Method] With tender kava leaves and stems with bud as explants, different hormone combinations were added into basic medium, to screen the optimal regeneration medium. [Result] The optimal induction medium for multiple shoots of kava was MS +4mg/L 6-BA +0.5mg/L GA3 +0.65% agar +3% sucrose +0.012 5% PVP; the optimal medium for elongation and rooting of shoots was 1/2MS +5nmol/L JA +0.65% agar +3% sucrose. [Conclusion] This study provides theoretical guidance for the enlargement of industrial production of kava.展开更多
[Objective]This study aimed to optimize the in vitro regeneration system of melon.[Method]Melon variety Nanxiang 91023 was selected as experimental materials,with the cotyledons and hypocotyls as explants,different ty...[Objective]This study aimed to optimize the in vitro regeneration system of melon.[Method]Melon variety Nanxiang 91023 was selected as experimental materials,with the cotyledons and hypocotyls as explants,different types and concentrations of growth regulators were supplemented at different stages of tissue culture,to explore the simple and effective medium formula for regeneration of melon.[Result]MS + 1.5 mg /L of 6-BA + 0.2 mg /L of IAA was the optimal medium for induction and proliferation of callus;MS + 1.0 mg /L of 6-BA + 0.2 mg /L of 2,4-D was the optimal medium for differentiation of adventitious buds;MS + 1.0 mg /L of ZT + 0.2 mg /L of IAA was the optimal medium for rooting of seedlings.On the basis of above conditions,melon seedlings had high rooting rate and strong roots.[Conclusion] This study provided a guarantee for the further genetic transformation of improved melon varieties.展开更多
Braking of the urban vehicles of public service wastes a large number of engine energy in the condition of starting and stopping frequently.Aiming at the problem,an electro-mechanical braking energy regeneration syste...Braking of the urban vehicles of public service wastes a large number of engine energy in the condition of starting and stopping frequently.Aiming at the problem,an electro-mechanical braking energy regeneration system was proposed which adopted a high-speed flywheel and a battery to recover the braking energy and achieve the secondary traction for the auxiliary start function.The system strategy was designed and the braking simulation was processed to validate its feasibility.The experiment results show that the system can effectively recover the braking energy,improve the starting performance of the city bus and it can be applied to the engineering.展开更多
[Objective] This study aimed to optimize the in vitro regeneration system of Benihoppe strawberry. [Method] Based on orthogonal experiment, the effects of different medium types, plant growth regulator types and conce...[Objective] This study aimed to optimize the in vitro regeneration system of Benihoppe strawberry. [Method] Based on orthogonal experiment, the effects of different medium types, plant growth regulator types and concentrations on the regeneration of adventitious shoots of Benihoppe strawberry leaves were investigated. [Result] IBA is an important factor affecting the multiplication of adventitious shoots of Benihoppe strawberry leaves; the optimal induction medium is MS + 2.0 mg/L TDZ + 0.2 mg/L IBA, with an induction rate of 90.00%; the optimal differentiation medium is MS + 2.0 mg/L 6-BA + 0.2 mg/L IBA, with a differentiation rate of 8.1%; the optimal multiplication medium is MS + 1.0 mg/L 6-BA + 0.2 mg/L IBA, with an average multiplication rate of each adventitious shoot of 7.67; the optimal subculture medium is MS + 0.5 mg/L 6-BA + 0.1 mg/L 2, 4-D, with an average seeding height in each treatment of 5.98 cm; the optimal rooting medium is 1/2MS + 0.5 mg/L 6-BA + 0.1 mg/L 2, 4-D, with an average number of roots in each treatment of 4.5. [Conclusion] This study laid the foundation for further investigating the genetic transformation of strawberry and improving the quality of strawberry at the genetic level.展开更多
[Objective]As a mosquito-repelling ornamental plant,Pelargonium×Citrosum Vanleenii(P.× Citrosum Vanleenii)is hard to be acquired because of its hybrid background,the paper was to a new regeneration system of...[Objective]As a mosquito-repelling ornamental plant,Pelargonium×Citrosum Vanleenii(P.× Citrosum Vanleenii)is hard to be acquired because of its hybrid background,the paper was to a new regeneration system of(P.× Citrosum Vanleenii).[Method] By studying the influence of plant growth regulators(PGRs)on explant type(leaves and petioles),the optimal combinations of PGRs to maximize SELSs(somatic embryo-like structure)and buds were established.[Result]0.2 mg/L NAA+1.0 mg/L BA was best for LS(leaves segments)and 0.2 mg/L NAA + 1.5 mg/L BAs was best for PS(petioles segments).Cultured plantlets were successfully acclimatized in soil where they grew normally without any morphological variation.Although both LS and PS were usable,the leaf was a better explant for induction of embryogenic calli,somatic embryo-like structures and buds.[Conclusion]This work offered a rapid and efficient system for plant regeneration of P.×Citrosum Vanleenii.展开更多
After pre-culture and treatment of osmosis, cotyledons of immature peanut (Arachis hypogaea L.) zygotic embryos were transformed via particle bombardment with a plasmid containing a chimeric hph gene conferring resist...After pre-culture and treatment of osmosis, cotyledons of immature peanut (Arachis hypogaea L.) zygotic embryos were transformed via particle bombardment with a plasmid containing a chimeric hph gene conferring resistance to hygromycin and a chimeric intron-gus gene. Selection for hygromycin resistant calluses and somatic embryos was initiated at 10th d post-bombardment on medium containing 10-25 mg/L hygromycin. Under continuous selection, hygromycin resistant plantlets were regenerated from somatic embryos and were recovered from nearly 1.6% of the bombarded cotyledons. The presence and integration of foreign DNA in regenerated hygromycin resistant plants was confirmed by PCR (polymerase chain reaction) for the intron-gus gene and by Southern hybridization of the hph gene. GUS enzyme activity was detected in leaflets from transgenic plants but not from control, non-transformed plants. The production of transgenic plants are mainly based on a newly improved somatic embryogenesis regeneration system developed by us.展开更多
The inability of damaged neurons to regenerate within the mature central nervous system(CNS)is a significant neuroscientific challenge.Astrocytes are an essential component of the CNS and participate in many physiolog...The inability of damaged neurons to regenerate within the mature central nervous system(CNS)is a significant neuroscientific challenge.Astrocytes are an essential component of the CNS and participate in many physiological processes including blood-brain barrier formation,axon growth regulation,neuronal support,and higher cognitive functions such as memory.Recent reprogramming studies have confirmed that astrocytes in the mature CNS can be transformed into functional neurons.Building on in vitro work,many studies have demonstrated that astrocytes can be transformed into neurons in different disease models to replace damaged or lost cells.However,many findings in this field are controversial,as the source of new neurons has been questioned.This review summarizes progress in reprogramming astrocytes into neurons in vivo in animal models of spinal cord injury,brain injury,Huntington’s disease,Parkinson’s disease,Alzheimer’s disease,and other neurodegenerative conditions.展开更多
Unlocking axon regeneration in the injured central nervous system:In adult mammals,central nervous system(CNS)neurons fail to regenerate a?ter a lesion,whether it is traumatic–after spinal cord injury for example–or...Unlocking axon regeneration in the injured central nervous system:In adult mammals,central nervous system(CNS)neurons fail to regenerate a?ter a lesion,whether it is traumatic–after spinal cord injury for example–or in the case of neurodegenerative diseases.This causes axons to degenerate and neurons to die.展开更多
文摘The criticality of transformers and reactors in the power transmission network and the paramount importance of ensuring their reliability through maintenance of the insulating oil is known. This paper presents a comprehensive examination of the efficacy and economic viability of a dielectric oil regeneration system, as implemented by the Transmission System Maintenance Department (TSMD) of the Independent Power Transmission Operator (IPTO), Greece’s sole transmission operator. Through a detailed chemical analysis and performance evaluation, we assess the impact of the regeneration system on treated insulating oil quality over multiple cycles. The study reveals that the electrical properties of the insulating oil are fully restored after regeneration, negating the need to fully replace it, while the investment becomes cost-neutral within weeks from the commissioning of the regeneration system. This economic analysis, coupled with the system’s environmental benefits of reducing waste oil generation, positions the dielectric oil regeneration system as a compelling solution for the maintenance of power transmission assets.
基金This work was fi nancially supported by the National Key Research Projects,Forestry Resource Cultivation and Utilization Technology Innovation(Grant No.2016YFD0600606)the Natural Science Foundation of Guangdong Province of China(Grant No.2018A030313798)Characteristic innovation projects of department of education of Guangdong province(Grant No.2019KTSCX017).
文摘We used the cotyledons and cotyledonary nodes of Toona ciliata(Chinese mahogany)as explants to examine callus and adventitious shoot induction when exposed to different ratios of hormones.We also investigated the effects of seedling age,inoculation method,and genotype on the efficient regeneration of T.ciliata.The results showed that different genotypes exhibited significantly different callus induction efficiency.The cotyledons and cotyledonary nodes of 20-day seedlings inoculated onto MS medium with 0.5 mg/L 6-benzylaminopurine(6-BA),0.5 mg/L kinetin(KT)and 0.05 mg/L 1-naphthylacetic acid(NAA)achieved a greater regeneration rate than did other concentrations of cytokinin and auxin.The numbers of shoots per cotyledon and cotyledonary node explant were 7.33 and 6.67.The optimal inoculation method for cotyledons was that the distal end of the explants was placed in contact with the medium.The optimal adventitious shoot differentiation medium for cotyledon explants was MS medium containing 0.3 mg/L 6-BA and 0.2 mg/L NAA,producing a 3.4 cm height of shoot on average.This study established an efficient regeneration system for T.ciliata with cotyledons and cotyledonary nodes as explants.
基金Supported by Guangxi Natural Science Foundation(2017JJB130027)The Basic Ability Enhancement Program for Young and Middle-aged Teachers of Guangxi(2017KY0724)Master’s Degree Authorization Unit Construction Authorization Point(GXW[2018]7)
文摘[Objectives]This study was conducted to establish a tissue culture regeneration system in Bama hemp(Cannabis sativa L.).[Methods]Using hemp seeds as explants,a regeneration system was established through explant sterilization,callus induction,callus differentiation,and rooting culture.[Results]The results showed that the best sterilization effect was achieved when sterilizing with 75%ethanol for 30 s,followed by 0.1%HgCl 2 solution for 9 min,with a contamination rate as low as 11.4%.In presence of 3 mg/L 2,4-D and 0.1 mg/L6-BA,the callus induction effect from hemp seeds was better.The formula for better differentiation of callus was MS+2.0 mg/L 6-BA+0.2 mg/L NAA.IBA had a promoting effect on the rooting of hemp aseptic plantlets.The highest rooting rate reached 80%when MS+0.3 mg/L IBA were used.[Conclusions]This study established a hemp seed regeneration system to provide technical support for the conservation and breeding of hemp germplasm resources.
基金Supported by Science and Technology Program of Sichuan Province(2018NZ0091)Special Project of Sichuan Provincial Public-Interest Scientific Institution Basal Research Fund+1 种基金Open Fund for Key Laboratory of Coarse Cereal Processing,Ministry of Agriculture and Rural Affairs(2018CC12)Scientific Research Projects of Sichuan Province Traditional Chinese Medicine Administration(2018KF007)
文摘[Objectives]To study the culture of callus produced by the leaves of the ethnic medicine‘E Se’,the induction of adventitious buds and the regeneration system of tissue culture seedlings.[Methods]Multi-factor orthogonal experiment was used to design and analyze.[Results]The best medium for callus induction was MS+2.0 mg/L 6-BA+0.1 mg/L 2,4-D.By comparing the effects of cytokinin 6-BA,KT and TDZ on induction of adventitious bud differentiation,it was found that the optimum medium for adventitious bud regeneration was MS+0.5 mg/L 6-BA+0.5 mg/L KT+0.15 mg/L IBA.Finally,adding 0.2 mg/L IBA(0.1 or 0.2 mg/L)to MS medium could effectively make regenerated seedlings produce roots,and the efficiency was more than 70%.[Conclusions]It laid a foundation for the large-scale cultivation of the seedlings of the ethnic medicine‘E Se’and the promotion of their artificial cultivation.
文摘Shoot meristems used for the study were exercised from the in vitro regenerated shoots cultured on MS medium supplemented with 0.5 mg/L of BAP for multiplication. The sensitivity of the in vitro regenerated was studied using shoot meristems of 0.5 cm. Shoot meristems were cultured on medium containing 10-100 mg/l kanamycin to determine the concentration that was lethal for multiple shoot induction and root induction. The response of shoot multiplication decreased (66.2%-6.2%) as the concentration of kanamycin increased (10.0-70.0 mg/L) with complete inhibition of shoot proliferation at 100 mg/L kanamycin. The rooting phase was very sensitive to kanamycin compared to shoot multiplication. The percentage of shoots that rooted decreased (53.8%-4.8%) with increase in the concentration of kanamycin (10.0-70.0 mg/l) on IBA and 2,4-D supplemented medium. For transformation studies, the shoot tips that were infected with Agrobacterium strain were placed on selection medium containing MS medium with 0.5 mg/L BAP and 100 mg/L kanamycin and scored for the putative transformed shoots. An average of 62.2% of shoot tips developed shoot buds from the base and the shoots reached a length of 0.5-1.0 cm at the end of 30 days of culture on the selective medium in comparison to control which showed no response. An average of 66.7% of the regenerated plants showed GUS expression on selection medium where 43.2% and 65% of GUS expression was recorded in the leaves and callus. Leaves and callus induced from the controls did not show GUS activity. Stable integration of nptII gene with the genomic DNA from these transformed plants was confirmed through PCR analysis. Our result presents an efficient regeneration system using in vitro derived shoot meristems for Agrobacterium mediated gene transfer.
基金This work is supported by the Grassland Talent Project:The Innovation Team of New Varieties Breeding at the Economic and Ecological Shrub,and the Evaluation of the Economic and Ecological Shrub Resources and New Variety Breeding in Inner Mongolia(No.201702077)。
文摘Hydrangea bretschneideri Dipp is a highly popular ornamental plant for garden decoration.Genetic engineering technology has been successfully used in many plant species,but it is limited in Hydrangea.Here we established an efficient regeneration system by using stem segments as explants for the first time.In our study,the plant growth regulators(PGRs)were evaluated at the different regeneration processes,including axillary shoots regeneration and root induction.We found that the optimal concentration for axillary buds’induction was 2.0 mgL^(-1)6-BA and 0.5 mgL^(-1)1 IAA,its highest induction rate was 70%.Moreover,the highest axillary shoots proliferation coefficient was 10.7 on the Murashige and Skoog(MS)medium with 2.0 mgL^(-1)6-benzyladenine(BA),0.2 mgL^(-1)indole-3-butyric acid(IBA),and 1.0 mgL^(-1)gibberellin A3(GA3).The highest frequency of root induction was 80.0±0.06%by culturing the elongated shoots in 1/2 MS medium containing 0.1 mgL^(-1)IBA.In summary,our study will provide an effective technology for large-scale propagation and important pathway for promoting the popularization and application of Hydrangea bretschneideri Dipp.
基金supported by National Natural Science Foundation of China(Grant No. 50875233)National Hi-tech Research and Development Program of China(863 Program, Grant No. 2010AA044401)+3 种基金Open Fund of the State Key Lab of Flow Power Transmission and Control(Grant No. GZKF-201111)National Youth Science Foundofion of China(Grant No. 51205140)Fundamental Research Funds for the Central University of China(Grant No. JB-ZR1208)Scientific Research Funds of Huaqiao University, China(Grant No. 11BS409)
文摘Though the traditional energy regeneration system(ERS) which used a hydraulic motor and a generator in hybrid excavators can regenerate part of the energy, the power of the motor and the generator should be larger and the time for regenerating energy is so short. At first, the structure of new ERS that combines the advantages of an electric and hydraulic accumulator is analyzed. The energy can be converted into both the electric energy and the hydraulic energy at the lowering of the boom and the generator can still works when the boom stops going down. Then, a method how to set the working pressure of the hydraulic accumulator is proposed. To avoid the excess loss, extra noise and shock pressure, a two-level pressure threshold method that the generator starts to work at the rising edge of the high pressure threshold and stops working at the falling edge of the low pressure threshold is presented to characterize the working mode of the generator. The control strategies on how to control the boom velocity at the lowering of the boom and how to improve the recovery efficiency when the boom stops going down are presented. The test bench of hybrid excavator with ERS is constructed, with which the studies on the influences of ERS on energy conversion efficiency and control performance are carried out. Experimental results show that the proposed ERS features better speed control performance of the boom than traditional ERS. It is also observed that an estimated 45% of the total potential energy could be regenerated at the lowering of the boom in the proposed ERS, and the power level of the generator and the hydraulic motor could be reduced by 60%. Hence, the proposed ERS has obvious advantages over the traditional ERS on the improvement of energy regeneration time, energy efficiency, control performance and economy.
文摘Citrus reticulata (Mandarin Orange), commonly known as “Sweet Orange”, is one of the most difficult plants to improve through traditional breeding approaches as it poses various biological limitations that greatly hinder the cultivar improvement. In the present study, using the fresh seed of native orange as explant, an efficient, reproducible, regeneration method was developed through in vitro organogenesis. Mature, healthy and dehusked seeds were treated with Murashige and Skoog, (MS) media containing 3% sucrose, 0.7% agar supplemented with different concentrations and combinations of phytohormones. The highest calli initiation (93.3% ± 0.5%) responses were observed on MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) at 3.0 mg/L followed by 2,4-D at 3.5 mg/L (86.7% ± 1.75%) in this experiment. Maximum shoot regeneration (86.7% ± 3.35%) responses were reported using MS medium supplemented with the combination of 6-benzylaminopurine (BAP) at 3.0 mg/L and 1-naphthaleneacetic acid (NAA) at 2.0 mg/L. MS medium supplemented with NAA at 1.0 mg/L showed the best rooting (80% ± 2.89%) response in comparison to (70% ± 5.20%) indole-3-butyric acid (IBA) at 1.0 mg/L. The regenerated plantlets were acclimatized in pots containing sterile garden soil mixture to examine their response in natural conditions.
基金funded by the National Natural Science Foundation of China (30971776)the National Transgenic Organism Research Program of China(2008ZX08010-004)
文摘Establishment of a highly efficient regeneration system for the mature embryo of wheat will provide a convenient tool for wheat tissue culture and transformation, thereby facilitating the transformation of foreign genes into wheat. By using the mature embryos derived from 20 different wheat lines including Shi 4185, Yumai 66, Lunxuan 987, CB037, Yangmai 6, Xinchun 9, Bobwhite, Han 6172, Zheng 9023, Jimai 20, Ningchun 4, and Jing 411, the effects of some factors including inoculation methods, initiating culture media, organic additives, antioxidants, and auxins on the regeneration from the explants were evaluated. The results indicated that the scraping embryo culture was better than the whole embryo culture, the Aa medium was better than the SD2 medium and dicamba was better than 2,4-D in increasing the regeneration frequency. An Adi medium was established in this study by adding silver nitrate, cysteine, ascorbic acid, dicamba, glutamine into the Aa medium at the concentration of 4 , 40, 100, 2, and 5 mg L-1, respectively. By using the Adi medium and the scraping technique, the regeneration frequencies of the mature embryos of CB037, Lunxuan 987, Han 6172, Yangmai 6, Bobwhite, Zheng 9023, Shi 4185, and Jimai 20 became 85.6, 60.1, 46.0, 42.1, 42.0, 34.0, 33.0, and 32.0%, respectively, which were about 5-8 times higher than that obtained from the conventional culture mediums and techniques. This novel regeneration system could be helpful in wheat transformation.
基金We thank Dr.Yang Zujun,Zhang Huaiyu,Yan Benju,Tan Feiquan,and Zhou Jianpin for their helpful comments in improving the manuscript.We also thank Cheng Jing for providing wheat cv.Bobwhite.This work was supported by 948 Project of Ministry of Agriculture,China(246)the National Natural Science Foundation of China(30170579).
文摘In the protocol of wheat transformation, to use elite wheat cultivars as exogenous gene recipients can speed up the process of commercial field applications of transgenic wheat. However, it is necessary to screen wheat cultivars with good tissue culture response (TCR) continuously from plenty of elite wheat cultivars released for wheat transformation, and it is also important to find a plant regeneration system that is suitable for these cultivars. So, the TCR of mature and immature embryos of six wheat cultivars Chuannong 11 (CN11), Chuannong12 (CN12), Chuannong17 (CN17), Chuannong18 (CN18), Chuannong19 (CN19), and Chuannong21 (CN21), which possess superior agronomic traits, were investigated by using a good TCR wheat cultivar Bobwhite as control. The results indicated that only the immature and mature embryos of CN12, CN17, and CN18 exhibited good TCR compared with Bobwhite. No significant differences were observed between embryos of Bobwhite and of the three cultivars in TCR. Mature embryo-derived calli of CN12 were used as explants for transformation by particle bombardment of SAMDC gene. Seven transformants were obtained and the efficiency was 2.3%. This research supplies three new elite recipient cultivars for wheat transformation. The wheat plant regeneration system used in this research is different from those successful ones reported previously and it could be a reference for other wheat genotypes. Furthermore, Bobwhite and the three wheat cultivars were proved to be 1RS/1BL translocation, by methods of A-PAGE, C- banding, and genomic in situ hybridization (GISH). These results imply that probably there is some relationship between 1RS/1BL translocation and TCR of wheat embryos. So this research gives us a hint that we should pay more attention to the 1RS/1BL translocations when we screen the wheat cultivars with good TCR and also that the mechanism of the effect of 1RS/ 1BL translocation on TCR is worthy of being investigated.
文摘Populus species are important resources for industry and in scientific study on biological and agricultural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar(Populus ciliata wall. ex Royle). The effect of TDZ alone and in combination with adenine and NAA was studied on the regeneration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glasshouses. After surface sterilization the explants were cultured on shoot induction medium. High percentage shoot regeneration(86 %) was recorded on MS medium supplemented with 0.004 mg L^-1TDZ and 79.7 mg L^-1adenine. The regenerated shoots for elongation and multiplication were transferred to MS + 0.5 mg L^-1BAP + 0.2 mg L^-1IAA +0.3 mg L-1GA3. Root regeneration from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L^-1IBA. Himalayan poplar plantlets could be produced within2 months after acclimatization in a sterile mixture of sand and soil. We developed a high efficiency plant regeneration protocol from petiole explants of P. ciliata.
文摘A reliable system was developed for regeneration from mature embryos derived from callus of four maize inbred lines (Liao 7980,Dan 9818,Dan 340,and Dan 5026). The protocol was mainly based on a series of experiments involving the composition of culture medium. We found that 9 μM 2,4-dichlorophenoxyacetic acid in MS medium was optimum for the induction of callus. The induction frequency of primary calli was over 85% for four inbred lines tested. The addition of L-proline (12 mM) in subculture medium significantly promoted the formation of embryogenic callus but it did not significantly enhance growth rate of callus. Efficient shoot regeneration was obtained on regeneration medium containing 2.22 μM 6-benzylaminopurine in combinations with 4.64 μM Kinetin. Regenerated shoots were rooted on half-strength MS medium containing 2.85 μM indole-3-butyric acid. This plant regeneration system provides a foundation for genetic transformation of maize.
文摘[Objective] This study aimed to establish in vitro regeneration system for Piper methysticum. [Method] With tender kava leaves and stems with bud as explants, different hormone combinations were added into basic medium, to screen the optimal regeneration medium. [Result] The optimal induction medium for multiple shoots of kava was MS +4mg/L 6-BA +0.5mg/L GA3 +0.65% agar +3% sucrose +0.012 5% PVP; the optimal medium for elongation and rooting of shoots was 1/2MS +5nmol/L JA +0.65% agar +3% sucrose. [Conclusion] This study provides theoretical guidance for the enlargement of industrial production of kava.
基金Supported by the Foundation of Hunan Provincial Department of Science and Technology(2010FJ3103)
文摘[Objective]This study aimed to optimize the in vitro regeneration system of melon.[Method]Melon variety Nanxiang 91023 was selected as experimental materials,with the cotyledons and hypocotyls as explants,different types and concentrations of growth regulators were supplemented at different stages of tissue culture,to explore the simple and effective medium formula for regeneration of melon.[Result]MS + 1.5 mg /L of 6-BA + 0.2 mg /L of IAA was the optimal medium for induction and proliferation of callus;MS + 1.0 mg /L of 6-BA + 0.2 mg /L of 2,4-D was the optimal medium for differentiation of adventitious buds;MS + 1.0 mg /L of ZT + 0.2 mg /L of IAA was the optimal medium for rooting of seedlings.On the basis of above conditions,melon seedlings had high rooting rate and strong roots.[Conclusion] This study provided a guarantee for the further genetic transformation of improved melon varieties.
基金supported by the Industrialization of Colleges and Universitis in Jiangsu Province Sponsored by Qing Lan Project
文摘Braking of the urban vehicles of public service wastes a large number of engine energy in the condition of starting and stopping frequently.Aiming at the problem,an electro-mechanical braking energy regeneration system was proposed which adopted a high-speed flywheel and a battery to recover the braking energy and achieve the secondary traction for the auxiliary start function.The system strategy was designed and the braking simulation was processed to validate its feasibility.The experiment results show that the system can effectively recover the braking energy,improve the starting performance of the city bus and it can be applied to the engineering.
基金Supported by Technology Development Project of Beijing Municipal Education Committee (KM201010020003)
文摘[Objective] This study aimed to optimize the in vitro regeneration system of Benihoppe strawberry. [Method] Based on orthogonal experiment, the effects of different medium types, plant growth regulator types and concentrations on the regeneration of adventitious shoots of Benihoppe strawberry leaves were investigated. [Result] IBA is an important factor affecting the multiplication of adventitious shoots of Benihoppe strawberry leaves; the optimal induction medium is MS + 2.0 mg/L TDZ + 0.2 mg/L IBA, with an induction rate of 90.00%; the optimal differentiation medium is MS + 2.0 mg/L 6-BA + 0.2 mg/L IBA, with a differentiation rate of 8.1%; the optimal multiplication medium is MS + 1.0 mg/L 6-BA + 0.2 mg/L IBA, with an average multiplication rate of each adventitious shoot of 7.67; the optimal subculture medium is MS + 0.5 mg/L 6-BA + 0.1 mg/L 2, 4-D, with an average seeding height in each treatment of 5.98 cm; the optimal rooting medium is 1/2MS + 0.5 mg/L 6-BA + 0.1 mg/L 2, 4-D, with an average number of roots in each treatment of 4.5. [Conclusion] This study laid the foundation for further investigating the genetic transformation of strawberry and improving the quality of strawberry at the genetic level.
基金Supported by Fund of Jinhua Science Technology Foundation of China(2009-2-02)
文摘[Objective]As a mosquito-repelling ornamental plant,Pelargonium×Citrosum Vanleenii(P.× Citrosum Vanleenii)is hard to be acquired because of its hybrid background,the paper was to a new regeneration system of(P.× Citrosum Vanleenii).[Method] By studying the influence of plant growth regulators(PGRs)on explant type(leaves and petioles),the optimal combinations of PGRs to maximize SELSs(somatic embryo-like structure)and buds were established.[Result]0.2 mg/L NAA+1.0 mg/L BA was best for LS(leaves segments)and 0.2 mg/L NAA + 1.5 mg/L BAs was best for PS(petioles segments).Cultured plantlets were successfully acclimatized in soil where they grew normally without any morphological variation.Although both LS and PS were usable,the leaf was a better explant for induction of embryogenic calli,somatic embryo-like structures and buds.[Conclusion]This work offered a rapid and efficient system for plant regeneration of P.×Citrosum Vanleenii.
基金the Natinnal Biotechnology Reseaxch Project of 863 High Technology, contract No. 101-01-01-02.
文摘After pre-culture and treatment of osmosis, cotyledons of immature peanut (Arachis hypogaea L.) zygotic embryos were transformed via particle bombardment with a plasmid containing a chimeric hph gene conferring resistance to hygromycin and a chimeric intron-gus gene. Selection for hygromycin resistant calluses and somatic embryos was initiated at 10th d post-bombardment on medium containing 10-25 mg/L hygromycin. Under continuous selection, hygromycin resistant plantlets were regenerated from somatic embryos and were recovered from nearly 1.6% of the bombarded cotyledons. The presence and integration of foreign DNA in regenerated hygromycin resistant plants was confirmed by PCR (polymerase chain reaction) for the intron-gus gene and by Southern hybridization of the hph gene. GUS enzyme activity was detected in leaflets from transgenic plants but not from control, non-transformed plants. The production of transgenic plants are mainly based on a newly improved somatic embryogenesis regeneration system developed by us.
基金supported by the National Natural Science Foundation of China,No.82071214(to JJL)Basic Scientific Research of the Central Public Research Institutes in China,No.2021CZ-2(to JJL)Special Fund for Joint Training of Doctoral Students between University of Health and Rehabilitation Sciences and China Rehabilitation Research Center,No.2020kfdx-009(to JJL and ZT)。
文摘The inability of damaged neurons to regenerate within the mature central nervous system(CNS)is a significant neuroscientific challenge.Astrocytes are an essential component of the CNS and participate in many physiological processes including blood-brain barrier formation,axon growth regulation,neuronal support,and higher cognitive functions such as memory.Recent reprogramming studies have confirmed that astrocytes in the mature CNS can be transformed into functional neurons.Building on in vitro work,many studies have demonstrated that astrocytes can be transformed into neurons in different disease models to replace damaged or lost cells.However,many findings in this field are controversial,as the source of new neurons has been questioned.This review summarizes progress in reprogramming astrocytes into neurons in vivo in animal models of spinal cord injury,brain injury,Huntington’s disease,Parkinson’s disease,Alzheimer’s disease,and other neurodegenerative conditions.
基金the French National Research Agency under the"Investissements d'avenir"program(ANR-17-EURE-0003)(to SB and HN)ERC-St17-759089-DRIVE and NRJ Foundation to HN and ANR ANR-18-CE16-0007 to SB+1 种基金a postdoctoral fellowship from Fondation pour la Recherche Médicale(FRM)SPF201909009106a PhD extension fellowship from Fondation pour la recherche médicale(FRM)-Programme Fin de Thèse FDT202204014716。
文摘Unlocking axon regeneration in the injured central nervous system:In adult mammals,central nervous system(CNS)neurons fail to regenerate a?ter a lesion,whether it is traumatic–after spinal cord injury for example–or in the case of neurodegenerative diseases.This causes axons to degenerate and neurons to die.
