An Efficient Plant Regeneration System for Different Explants of Rare and Endangered Plants in Mussaenda anomala

To establish an efficient regeneration method for the rare and endangered plant Mussaenda anomala to address problems regarding its reproductive obstacles and scarce populations.In this study,the terminal buds,axillary buds,stem segments with two axillary buds,stem segments with two axillary buds and one terminal bud,and leaves of M.anomala were used as explants.The effects of different explants and disinfection methods,plant growth regulators and substrates on plant regeneration were explored.The following results were obtained:(1)The terminal bud was a suitable explant for M.anomala tissue culture,and the disinfection method utilized was treatment with 0.2%HgCl2 for 8 min.(2)Initiate medium:MS basic medium supplemented with 0.5 mg/L 6-BA and 0.2 mg/L IBA for the high germination rate(100%)and the maximum bud height(1.70 cm)of the terminal bud.(3)Proliferation medium:MS basic medium supplemented with 3.0 mg/L 6-BA and 0.2 mg/L IBA for a high proliferation rate(96%)and proliferation time(6.0)of terminal buds.(4)Proliferation medium supplemented with 0.7 mg/L GA3 significantly increased the bud heights of multiple buds.(5)Rooting medium:MS basic medium supplemented with 0.5 mg/L IBA and 0.5 mg/L IAA for a high rooting rate(88%),root number(12.0)and root length(5.07 cm).(6)The optimal substrate for seedling acclimation and transplanting was perlite:vermiculite(1:1),which resulted in the highest survival rate(97%)and plant height(5.89 cm),as well as better growth potential for seedlings.The surfaces of M.anomala explants are densely covered with trichome,which increased the difficulty of disinfection;the plant growth regulators directly affected the growth and development in the regeneration process of M.anomala,and the substrate significantly affected the survival rate and height growth for seedling acclimation.

Benefits of Dielectric Oil Regeneration Systems in Power Transmission Networks: A Case Study

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.

Establishment of High Frequency Regeneration System of Atropa belladonna L. and Screening of Kanamycin Resistance

[Objective] The research aimed to establish the high frequency regeneration system of Atropa belladonna L. and screen the kanamycin （Kan） resistance. [Method] The leaves and axillary buds of Atropa belladonna L. were as the explants,the influences of different ratios of 6-BA and NAA in the medium on the adventitious bud differentiation and the sensibility of leaf on Kan were studied. [Result] MS＋4.5 mg/L 6-BA＋0.2 mg/L NAA was the optimum medium of leaf adventitious bud differentiation,and the differentiation ratio of adventitious bud reached 100%. The number of adventitious bud differentiation on 1. 0 cm ×1. 0 cm leaf block averagely reached 5.85. MS＋3.0 mg/L 6-BA＋0.1 mg/L NAA was the optimum medium of axillary bud adventitious bud differentiation,and the differentiation ratio of adventitious bud reached 100%. The average number of adventitious bud differentiation in every axillary bud was during 4-8. The optimum screening concentration for genetic transformation of Atropa belladonna L. leaf was 400.0 mg/L of Kan. [Conclusion] The research laid the foundation for the rapid propagation of Atropa belladonna L. aseptic seedling and the genetic transformation based on the leaf disc cocultivation.

Establishment of High Frequency Regeneration System of Populus tomentosa

The establishment of high frequency regeneration system is a foundation for Agrobacterium mediated genetic transformation. In this work, several important factors influencing the efficiency of regeneration of plants, such as concentration of plant growth regulators, leaf explant orientation, leaf growth sequence and leaf segment, were studied. The results indicated that the differentiation rate of adventitious shoots was 90% on basal MS medium only supplemented with 1 5?mg·L -1 BA (6 benzyladenine) and reached the highest level(95%) when 1 0?mg·L -1 BA and 0 3?mg·L -1 NAA (naphthaleneacetic acid) were added to MS medium. 90% of differentiation rate of adventitious roots were obtained when 0 3?mg·L -1 NAA was only added to MS medium. It was also found that more adventitious shoots were regenerated from the lower segment of leaf (with petiole) than the other segments, the number of adventitious shoots decreased from top to base of leaf growth sequence and the percentage of adventitious shoot induction with adaxial side downward was higher than that with adaxial side upward.

Hydraulic Accumulator-Motor-Generator Energy Regeneration System for a Hybrid Hydraulic Excavator

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.

A regeneration system using cotyledons and cotyledonary node explants of Toona ciliata

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.

Establishment of Tissue Culture Regeneration System in Bama Hemp (Cannabis sativa L.)

[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.

Establishment of Plant Regeneration System from Immature Embryos of Maize(Zea mays L.) Inbred Lines

[Objective] The aim was to explore the conditions of high frequency induction of embryonic callus and plant regeneration of maize. [Method] Immature embryos of maize inbred lines were used as explants to study the effect of different 2,4-D concentrations on the induction of callus,the effect of different 6-BA concentrations on the differentiation of test-tube plantlet,as well as the effect of different IBA concentrations on the rooting of test-tube plantlet. [Result] 2,4-D showed obvious effect on the induction of inducement rate of maize,and the optimum induction medium was：N6 ＋ 2 mg/L of 2,4-D ＋ 500 mg/L of CH ＋ 500 mg/L of Pro ＋10 mg/L of AgNO3; the optimum differentiation medium was：N6 ＋ 0.5 mg/L of BA ＋ 500 mg/L of Pro; the optimum for the rooting of test-tube plantlet was 1/2 MS ＋ 0.5 mg/L of IBA. [Conclusion] The study had provided basis for the genetic transformation of maize.

Optimization of Regeneration System of Leaf and Stem of Populus euramericana 108

[Objective] The aim was to optimize the culture conditions for asexual reproduction system of Populus euramericana 108.[Method] Orthogonal designs were adopted optimize the culture conditions of the regeneration system for direct differentiation from leaves and induced callus from stems of P.euramericana 108 aseptic seeding.[Result] Leaves of P.euramericana 108 directly regenerated and differentiated under illumination,while stem segments preferred to regenerate and differentiate through callus induction under illumination.The differentiation medium of adventitious buds from leaves was MS medium （agar 7.0 g/L,pH 6.0,sucrose 20 g/L） added with 0.6 mg/L 6-BA and 0.2 mg/L NAA; callus induction medium of stem segments was WPM solid medium added with 0.75 mg/L KT and 1.5 mg/L 2,4-D.Rooting induction medium for adventitious buds was WPM solid culture （sucrose 30 g/L） added with 2.0 mg/L IBA.[Conclusion] The culture conditions for regeneration system of differentiation from leaves and induced callus of stems were optimized,which provides basis for the construction of tissue culture and genetic transformation system.

Optimization of plant regeneration system in vitro culture in wheat

Studies were carried out to establish an efficient regeneration system of three bread wheat cultivars. Results showed induction medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) had a higher plantlet regeneration frequency than Piclorm, with an average frequency of 54% in all treatments. Optimal condition for different genotypic rice was as following: induction medium (MSS 3AA/2) with 0.5 mg L-1 2,4-D, regeneration medium (R) with 0.01 mg L-1 2,4-D and 3 mg L-1 KT. The average regeneration frequency reached 83.3% under the condition. Correlation analysis showed that root differentiation, in different level, correlated with green spot regeneration, and with the number of regenerated plants per callus. No correlation was found between green spots regenerated and the numbers of plants regenerated per callus.

Construction of Highly-efficient Direct Regeneration System of Different Chrysanthemum Species

Leaves and stems of 9 chrysanthemum species were taken as explants and inoculated to 6 differential media and root media to research effects of hor- mone combination and explants on chrysanthemum species. The results indicated that stem of 9 chrysanthemum species and leaf of 6 chrysanthemum species all showed higher regeneration capacity, with regeneration rate in 84%-100% and re- generation coefficient at 2.3-9.4. However, none adventitious buds were found differ- entiated from leaves of ＂28＂ and ＂5-17＂, and leaf regeneration capacity of ＂11＂ was lower, either. Most chrysanthemum species proved higher in stem regeneration ca- pacity, instead of leaf. Therefore, chrysanthemum species can be applied for rapid reproduction and genetic engineering.

Development of an Efficient Plant Regeneration System for Pelargonium×Citrosum Vanleenii

[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.

Study on In vitro Regeneration System of Melon

[ Objective] This study aimed to optimize the in vitro regeneration system of melon. [ Method] Melon variety Nanxiang91023 was selected as experi- mental materials, with the cotyledons and hypocotyls as explants, different types and concentrations of growth regulators were supplemented at different stages of tis- sue 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 LAA 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 LAA was the optimal medium for rooting of seedlings. On the basis of above conditions, melon seedlings had high roofing rate and strong roots. [ Conclusion] This study provided a guarantee for the further genetic transformation of improved melon varieties.

Establishment of Regeneration System In vitro for Piper methysticum

[ 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 ＋ 4 mg/L 6-BA ＋ 0.5 mg/L GA3 ＋ 0.65% agar ＋ 3% sucrose ＋ 0.012 5% PVP; the optimal medium for elongation and rooting of shoots was 1/2MS ＋ 5 nmal/L JA ＋ 0.65% agar ＋ 3 % sucrose. [ Conclusion] This study provides theoretical guidance for the enlargement of industrial production of kava.

Establishment of Regeneration System of Bougainvillea ‘Yunnan Purple’ Stem Segment

To optimize the regeneration system of Bougainvillea, the effects of different hormone ratios and concentrations on axillary bud induction, proliferation and re-rooting were studied using annual semi-lignified branch cuttings of Bougainvillea ‘Yunnan Purple’ as experimental materials. The results showed that MS+6-BA 2.5 mg/L+NAA 0.1 mg/L was the optimal medium for stem axillary bud initiation, and the initiation rate reached 91.3%. The optimal medium for axillary bud proliferation was MS+6-BA 1.0 mg/L+NAA 0.2 mg/L, and the proliferation coefficient was 3.28. The optimal rooting medium was 1/2 MS+IBA 1.0 mg/L, with the rooting rate of 90% and the average root number of 7.4. After 15 d of hardening seedling, the survival rate of the sterile seedlings was 97.83%. This study laid a basis for rapid propagation and genetic transformation system of Bougainvillea.

Establishment of a Highly Efficient Regeneration System for the Mature Embryo Culture of Wheat

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, Hart 6172, Yangmai 6, Bobwhite, Zheng 9023, Shi 4 185, 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.

The Selection of Transgenic Recipients from New Elite Wheat Cultivars and Study on Its Plant Regeneration System

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.

Thansgenic peanut plants obtained by particle bombardment via somatic embryogenesis regeneration system

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.

Establishment of high frequency shoot regeneration system in Himalayan poplar(Populus ciliata Wall. ex Royle) from petiole explants using Thidiazuron cytokinin as plant growth regulator

Populus species are important resources for industry and in scientific study on biological and agricul- tural 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 combi- nation with adenine and NAA was studied on the regen- eration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glass- houses. After surface sterilization the explants were cul- tured on shoot induction medium. High percentage shoot regeneration （86 %） was recorded on MS medium sup- plemented with 0.004 mg L-1 TDZ and 79.7 mg L-1 adenine. The regenerated shoots for elongation and multi- plication were transferred to MS ＋ 0.5 mg L-1 BAP ＋ 0.2 mg L-1 IAA ＋ 0.3 mg L-1 GA3. Root re- generation from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L-1 IBA. Hi- malayan poplar plantlets could be produced within 2 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.

Establishment and Optimization of the Regeneration System of Mature Embryos of Maize (Zea mays L.)

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 pM 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.