Somatic embryogenesis of Fraxinus mandshurica has the problems of low somatic embryo(SE) yield,unsynchronized SE development,and a high percentage of deformed SEs.We aimed to improve F.mandshurica SE production by syn...Somatic embryogenesis of Fraxinus mandshurica has the problems of low somatic embryo(SE) yield,unsynchronized SE development,and a high percentage of deformed SEs.We aimed to improve F.mandshurica SE production by synchronizing SE development,improving SE quality,and inducing root formation to obtain complete regenerated plants.Cotyledons of immature zygotic embryos of F.mandshurica were induced to form callus and then SEs.The SE induction percentage from explants differed among 32 mother trees,and the one with the highest SE induction percentage(29.8%) was used for further experiments.The highest callus induction percentage was94.2% on 1/2-strength Murashige and Skoog medium(MS1/2)supplemented with 0.15 mg·L^(-1) naphthalene acetic acid.The highest callus proliferation coefficient(240.5) was obtained on McCown's Woody Plant Medium containing 0.1 mg·L^(-1)6-benzyl adenine and 0.15 mg·L^(-1) 2,4-dichlorophenoxyacetic acid.The highest number of SEs(1020.5 g~(-1) fresh weight) was obtained on MS1/2 medium supplemented with1 mg·L^(-1) 6-benzyladenine.The highest number of cotyledon embryos(397/g fresh weight) was obtained by incubating materials on medium containing 1 mg·L^(-1) abscisic acid and then applying a drying treatment.The cotyledon embryos were milky white,uniformly sized(average length 4.7 mm),and 80% of them were normal.The SE rooting percentage on 1/2 MS medium containing 0.01 mg·L^(-1) NAA was 37.5%.Overall,the germination percentage of SEs was 26.4%,and complete regenerated plants were obtained after transplanting and acclimation.These results provide more possibilities for the preservation and breeding of F.mandshurica.展开更多
Adventitious shoots were successfully regenerated from hypocotyl explants of in vitro cultures of Euonymus japonicus Cu zhi. Hypocotyl slices were cultured on Murashige and Skoog (MS) and B5 basal medium supplemente...Adventitious shoots were successfully regenerated from hypocotyl explants of in vitro cultures of Euonymus japonicus Cu zhi. Hypocotyl slices were cultured on Murashige and Skoog (MS) and B5 basal medium supplemented with varied concentration of different plant growth-regulators, e.g., α-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA) in combination with 6-benzylaminopurine (6-BA) and kinetin. The study showed that shoots could be directly regenerated from hypocotyl explants without the intervening callus phase; MS medium was more suitable for adventitious shoots regeneration. The ability of hypocotyls segments to produce shoots varied depending upon their position on the seedlings. The highest regeneration rate was obtained with hypocotyl segments near to the cotyledon cultured on MS basal medium supplemented with 1.5 mg L^-1 6-BA and 0.05 mg L^-1 NAA (63.64%). The regenerated shoots were readily elongated on the same medium as used for multiplication and rooted on half-strength MS basal medium supplemented with 1.0 mg L^-1 IBA and 100 mg L^-1 activated carbon. After being transferred to greenhouse conditions, 96% of the plantlets were successfully acclimatized. This regeneration system is applied for genetic transformation now.展开更多
In this paper,we describe briefly an efficientculture procedure for micro-propagation of riceregeneration plants.The procedure consists ofthe following steps: 1.Preparation of materials Calli wereinduced from mature ...In this paper,we describe briefly an efficientculture procedure for micro-propagation of riceregeneration plants.The procedure consists ofthe following steps: 1.Preparation of materials Calli wereinduced from mature seeds of an indica rice lineG67 by culturing the husked and disinfectedseeds on agar medium,consisting of Nbasalelements,3% sucrose,1000mg/L proline,and 32mg/L 2,4-D.After one month's in- duction culture and 3 wk subculture,compactand nodular calli were picked out and trans- ferred into liquid medium for suspension cul-tures.The liquid medium contained the same展开更多
The success for genetic transformation of maize (Zea mays L.) is highly related to genotype of target material. A few model varieties can be induced into type Ⅱ callus, which can be easily transformed with high regen...The success for genetic transformation of maize (Zea mays L.) is highly related to genotype of target material. A few model varieties can be induced into type Ⅱ callus, which can be easily transformed with high regeneration frequency. However, most of cultivars could be only induced into type Ⅰ callus, which is difficult to be transformed with low regeneration. Thus, studying on the conditions of induction and transformation for type Ⅰ callus will show great importance for improving elite of maize directly with genetic engineering. Bacillus thuringiensis toxin protein (cry1Ac3) gene was successfully delivered into type Ⅰ calli of two elite inbred lines of maize, 340 and E28, via particle bombardment in this work. Fertile transgenic corn plants were obtained through phosphinothricin (PPT) or hygromycin B (HygB) selection, and the results of PCR, Southern blot assay and ELISA showed that foreign genes had been integrated into maize genome and expressed. In the meantime, strong resistance of some transgenic plants to corn borer was showed through bioassay. In addition, the comparison of selective effect between PPT and HygB showed that PPT, as a selective agent, was better than HygB for the growth and regeneration of resistant calli.展开更多
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
An in vitro shoot regeneration procedure was developed in pepper ( Capsicum annuum L. ) cytoplasmic male sterility (CMS) lines 9704A and 8214A using cotyledon as explant. The callus and bud cluster derived from co...An in vitro shoot regeneration procedure was developed in pepper ( Capsicum annuum L. ) cytoplasmic male sterility (CMS) lines 9704A and 8214A using cotyledon as explant. The callus and bud cluster derived from cotyledon tissue explants were proliferated on Murashige and Skoog (MS) medium supplemented with different combinations of 6-benzladenine (6-BA), indole-3-acetic acid (IAA), gibberellic acid (GA3) and silver nitrate (AgNO3). From the formula of MS appended with 5.0 mg/L 6-BA, 1.0 mg/L IAA and 5.0 mg/L AgNO3, for the explants callus and bud cluster, the maximum differentiation rates ( respectively 100.0% and 58.3% ) and average number of adventitious bud from each explant (respectively 18.8 and 13.2) were obtained. The optimum medium combination for the elongation of adventitious bud was determined to be: MS + 3.0 mg/L 6-BA + 1.0 mg/L IAA + 5.0 mg/L AgNO3 + 2.0 mg/L GA3, from which the elongation rates of buds from callus and bud cluster were both 100%, and the average number of per explant adventitious bud number reached 6.3 and 5.8, respectively. And all the elongated shoots were successfully rooted on half-strength MS medium supplemented with 0.3-0.5 mg/L IAA.展开更多
[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 eff...[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.展开更多
Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues of...Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues often become severely necrotic after co-cultivation with Agrobacterium, which is one of the major obstacles in gene delivery. In this study, wheat varieties CB037, Kenong 199, Xinchun 9, Lunxuan 987, and Shi 4185 showed desirable culture potential or high infection ability in Agrobacterium-mediated transformation. Similarly, optimal regeneration conditions were determined by testing their ability to inhibit the cell necrosis and cell death phenotype. Two auxins of 2,4-dichlorophenoxyacetic acid (2,4-D) and 3,6-dichloro-o-anisic acid (dicamba) were evaluated for highly significant effect on both callus and plantlet production, although they were genotype-dependent in wheat. Substitution of 2,4-D by dicamba enhanced the growth and regeneration ability of callus from the immature embryos of most genotypes tested. The callus growth state couldn’t be modified by adding antioxidants such as ascorbic acid, cysteine, and silver nitrate or organic additives such as thiamine HCl and asparagine to the media. On the contrary, the best tissue statement and plant regeneration was achieved by employing the media containing the simplest MS (Murashige and Skoog) components and dicamba without organic components and vitamins. Thereby, our results are thought to inhibit wheat cell necrosis effectively and suggested to be used for more wheat genotypes.展开更多
To reveal the suitability of using mature embryos as an explant source in wheat tissue culture, mature embryos from eight common wheat cultivars (Triticum aestivum L. cv.) were cultured with or without endosperm to ...To reveal the suitability of using mature embryos as an explant source in wheat tissue culture, mature embryos from eight common wheat cultivars (Triticum aestivum L. cv.) were cultured with or without endosperm to test their efficiency of callus induction and plant regeneration. When embryos were cultured together with endosperm (endosperm-supported culture, ES), the percentage of callus induction was significantly lower than that when embryos were cultured in the absence of endosperm (non-endosperm-supported culture, NES). This pattern was evident in most genotypes, regardless of whether 2 or 8 mg L^-1 2,4-D was added in the NES culture. However, in ES culture, more induced calli were differentiated into distinct green spots and they further developed into plantlets. Thus, more plants were regenerated in ES culture than in the NES treatment. Most of the eight tested genotypes showed a significant difference in callus induction rate and plantlet regeneration in both ES and NES cultures. In addition, the enzymatic activity of oxalate oxidase in the callus of ES culture condition was obviously higher than that in the callus of NES culture condition, suggesting that the activity of oxalate oxidase may be a parameter for selection of calli with potential for plantlet regeneration. These results indicate that wheat mature embryos are valuable explants for highly efficient callus induction and plant regeneration, if proper treatment and medium are used.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
The immature embryos (IEs) of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4℃ daily...The immature embryos (IEs) of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4℃ daily cooler for a short period time for its use in plant tissue culture or transformation experiments. This study aimed to investigate the effects of environmental temperature, cryopreservation storage temperature, and heat shock culture (HSC) temperature on the regeneration frequency of wheat IEs. Results indicated that environmental temperature significantly affected the induction of embryonic calli. The optimum total accumulated temperature (TAT) during the time of anthesis and sampling for regeneration of these tissues was around 280℃ for spring wheat type cv. CB037 and approximately 300℃ for winter wheat type cv. Kenong 199. Regeneration ability obviously declined when the highest environmental temperature was over 35℃ for 1 d or a high temperature between 30 and 33℃ lasted for 5 d during anthesis and sampling. This finding was verified by culturing the freshly isolated IEs under different temperatures from 29 to 37℃ in different controlled growth incubators for 5 d; the IEs almost completely lost regeneration ability when the temperature rose to 37℃. Cryopreservation of-20℃ caused the wheat samples lost ability of producing callus or embryonic callus in a few days, and cryopreservation of-10℃ more than 10 d made the regeneration potential of the tissues dramatically declined. Comparatively, the temperature that best maintained high regeneration ability was -5℃, at which the materials can be maintained for around 1 mon. In addition, the preservation of the immature samples at -5 or -10℃ inhibited the direct germination of the IEs, avoiding the embryo axis removing process. Our results are useful for ensuring that field collection and cryopreservation of the wheat IEs are done correctly to enable tissue culture and genetic transformation.展开更多
To establish a highly efficient plant regeneration system for wheat genetic transformation, the effects of three different concentrations of dicamba and two different sugar types on callus induction and plant regenera...To establish a highly efficient plant regeneration system for wheat genetic transformation, the effects of three different concentrations of dicamba and two different sugar types on callus induction and plant regeneration from mature embryo cultures were evaluated. Callus induction and plant regeneration were obtained from mature embryos of two commercial cultivars Zhoumai 18 and Yumai 34 (Triticum aestivum L.) cultured on L3 basal medium. The results showed that the efficiency of mature embryo culture was significantly influenced by the genotypes, sugar types and dicamba concentrations. 4 mg L^-1 dicamba proved the best effective for inducing embryogenic callus and also gave the highest proportion of plants regenerated across the two cultivars. Substitution of maltose by sucrose significantly improved the plant regeneration efficiency in both cultivars. There was a significant interaction between genotype-by-sugar types, and sugar types-bydicamba concentrations. Overall, Zhoumai 18 gave the highest frequency of plant regeneration (82.65%) when dicamba concentration was 4.0 mg L^-1 and with sucrose in initial callus induction. These results will facilitate genetic transformation work with elite wheat.展开更多
This research aims at developing a plant regeneration system from leaf and petiole explants of Anthurium andraeanum Hort., thereby establish a foundation for mass production and transformation. Using tissue culture te...This research aims at developing a plant regeneration system from leaf and petiole explants of Anthurium andraeanum Hort., thereby establish a foundation for mass production and transformation. Using tissue culture technique, the conditions for callus induction, protocorm-like body (PLB) formation and plant regeneration from leaf explants and petiole of A. andraeanum, such as basal medium and plant growth regulator, were investigated. Totipotent callus was induced on a 1/2-strength MS medium containing 0.90 μmol L^-1 2,4-dichlorophenoxyacetic acid (2,4-D) and 8.88μmol L^-1 N6-benzyladenine (BA). The callus exhibited complete hormone autonomy for growth and differentiation of PLBs. This callus proliferated well and was maintained by subculturing on 1/2 MS medium containing 0.90 μmol L^-1 2,4-D and 4.44 μmol L^-1 BA. On average, 8 protocorm-like bodies could be obtained from a piece of 4 mm callus after being transferred to the 1/2 MS medium with 4.44 μmol L^-1 BA after 8 wk of culture. The regenerated PLBs formed shoots and roots on 1/2 MS medium. After 24 wk of culture on these medium, well-developed plantlets for potting were produced. An efficient micropropagation method was established for indirect PLB formation and plant regeneration from leaf and petiole ofA. andraeanum.展开更多
An improved protocol has been developed for somatic embryogenesis and plant regeneration of recalcitrant cotton cultivars. High callus frequencies and embryogenic tissue were developed in MSB medium supplemented with ...An improved protocol has been developed for somatic embryogenesis and plant regeneration of recalcitrant cotton cultivars. High callus frequencies and embryogenic tissue were developed in MSB medium supplemented with gradient concentrations of KT and 2,4-D, their concentration decreasing from 0.1 to 0.01 mg·L^-1. Somatic embryos were successfully incubated in 1/2 macronutrient MSB suspension supplemented with 0.5 g· L^-1 glutamine and 0.5 g·L^-1 asparagine. Decrease in macronutrient concentration of MSB significantly alleviated browning and was beneficial to suspension cells. Transformation of somatic embryos into plants was induced in MSB medium supplemented with 3% sucrose, 0.5 g·L^-1 glutamine, 0.5 g·L^-1 asparagine, and 6.0 g·L^-1 agar. The effect of sucrose as carbohydrate was better than that of glucose for plant germination. Using this protocol, regenerated plantlets from the CCRI521 and Zhongzhi86-6 reached to as much as 19.6 and 18.5% somatic embryos, respectively.展开更多
The regeneration rate of wheat immature embryo varies among genotypes, howbeit many elite agriculture wheat varieties have low regeneration rates. Optimization of tissue culture conditions and attempts of adding signa...The regeneration rate of wheat immature embryo varies among genotypes, howbeit many elite agriculture wheat varieties have low regeneration rates. Optimization of tissue culture conditions and attempts of adding signal molecules are effective ways to increase plant regeneration rate. Inter-culture is one of ways that have not been investigated in plant tissue culture. Moreover, the use of arabinogalactan proteins (AGPs) and hydrogen peroxide (H202) have been reported to increase regeneration rate in a few plant species other than wheat. The current research pioneeringly uses inter-culture of immature embryos of different wheat genotypes, and also investigates impacts of AGP and H2O2 on the induction of embryogenic calli and plant regeneration. As a result, high-frequency regeneration wheat cultivars Kenong 199 (KN 199) and Xinchun 9 (XC9), together with low-frequency regeneration wheat line Chinese Spring (CS), presented striking increase in the induction of embryogenic calli and plant regeneration rate of CS through inter-culture strategy, up to 52.19 and 67.98%, respectively. Adding 50 to 200 mg L-1 AGP or 0.005 to 0.01‰ H2O2 to the callus induction medium, enhanced growth of embryogenic calli and plant regeneration rate in quite a few wheat genotypes. At 50 mg L-1 AGP application level in callus induction medium plant regeneration rates of 8.49,409.06 and 283.16% were achieved for Jimai 22 (JM22), Jingdong 18 (JD18) and Yangmai 18 (YM18), respectively; whereas at 100 mg L-1 AGP level, CS (105.44%), Chuannong 16 (CN16) (80.60%) and Ningchun 4 (NC4) (62.87%) acted the best. Moreover CS (79.05%), JM22 (7.55%), CN16 (101.87%), YM18 (365.56%), Yangmai 20 (YM20) (10.48%), and CB301 (187.40%) were more responsive to 0.005 %o of H2O2, and NC4 (35.37%) obtained the highest shoot regeneration rates at 0.01%o of H2O2. Overall, these two methods, inter-culture and AGP (or H2O2) application, can be further applied to wheat transgenic research.展开更多
An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with...An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growthregulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation isbeneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formationefficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAPand 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds perinternodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and weretransferred to the soil.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 experime...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.展开更多
Switchgrass is native to the tallgrass prairie of North America. It is self-incompatible and has varied ploidy levels from diploid(2x) to dodecaploid(12x) with tetraploid and octoploid being the most common. The h...Switchgrass is native to the tallgrass prairie of North America. It is self-incompatible and has varied ploidy levels from diploid(2x) to dodecaploid(12x) with tetraploid and octoploid being the most common. The high yielding potential and the ability to grow well in marginal lands make switchgrass an ideal species as a dedicated biomass producer for lignocellulosic ethanol production. Genetic transformation is an important tool for studying gene function and for germplasm improvement in switchgrass, the genome of which has been sequenced recently. This paper intends to provide a comprehensive review on plant regeneration and genetic transformation in switchgrass. We first reviewed the effect of explants, basal medium and plant growth regulators on plant regeneration in switchgrass, which is a prerequisite for genetic transformation. We then reviewed the progresses on genetic transformation with either the biolistic or Agrobacterium-mediated method in switchgrass, and discussed various techniques employed to improve the transformation efficiency. Finally we reviewed the recent progresses on the use of genetic transformation in improving biomass quality such as the reduction of lignin, and in increasing biomass yield in switchgrass. We also provided a future perspective on the use of new genome editing technologies in switchgrass and its potential impact on regulatory processes.展开更多
Morus alba(white mulberry) mesophyll protoplasts were isolated from leaves of 30-45 day old sterile shoots,with protoplast yields of 2.5 x 107 g-1/F.W. after purification. The protoplasts were cultured in a modified K...Morus alba(white mulberry) mesophyll protoplasts were isolated from leaves of 30-45 day old sterile shoots,with protoplast yields of 2.5 x 107 g-1/F.W. after purification. The protoplasts were cultured in a modified K8P liquid medium containing 0.2 mg/L 2,4-D(2,4- Dichlorophe-noxy acetic acid), 1 mg/L NAA(Naphthyl acetic acid) and 0.5 mg/L BA(6-benzylaminopurine). A low plating density (5 x 104/ml) proved to be favourable to the division of protoplast-derived cells. The first divisioll occurred 4 days after culture, and the division frequency reached 24% at 10 days. A number of cell colonies and microcalli formed in 6 weeks. The microcalli were transferred onto MSB medium with 0.5 mg/L NAA and 0.5 mg/L BA for further proliferation. Shoot formation was initiated when the calli of 3-4 mm in size were transferred onto MSB differentiation medium with 0.1 mg/L NAA and 1 mg/L BA. The frequency of shoot formation was 35%. The shoots of 4-5 cm in height were excised from the callus and rooted on half strength MS medium with 0.5 mg/L IBA and 0.1 mg/L BA. After transplantation into pots, the regenerated plants grew vigorously in the phytotron.展开更多
This research uses the immature embryos of inbred maize lines(GSH9901,Hi01,Hi02,and Chang 7-2)as receptor materials to establish the callus induction system.These inbred lines provide the receptor materials for the ge...This research uses the immature embryos of inbred maize lines(GSH9901,Hi01,Hi02,and Chang 7-2)as receptor materials to establish the callus induction system.These inbred lines provide the receptor materials for the genetic regeneration of maize and the verification of the genetic functions of maize.The factor experiment and orthogonal experiments were used to investigate the impacts of different genotypes,immature embryo size,shield orientation,2,4-D concentration,proline concentration,and folic acid concentration on the induction rate of embryogenic callus tissue.A sensitivity experiment testing glyphosate(Bar)and an antibiotic(Cefotaxime sodium)were also conducted.The results indicate that the immature embryos of inbred maize line GSH9901 were the most effective for callus tissue induction,and the immature embryos with a length of 1.6-2.0 mm produce the best result.The upward shield face is more successful for the formation of induced callus.Using orthogonal analysis,we found that the optimal combination for the induction system was A_(3)(2,4-D concentration 0.25 mg mL^(-1)),B_(1)C_(3)(proline concentration 0.8 mg mL^(-1)),and D 2(folate Concentration 0.5 mg mL^(-1))and the induction rate reached 84%.We found that cold storage at 4℃ for 1 d is more conducive for the formation of embryogenic callus than the other treatments tested.The sensitivity experiment for callus tissue screening revealed the critical concentration of glyphosate to be 10 mg ml^(-1),and the critical concentration of antibiotic is 250 mg ml^(-1).Using this combination of glyphosate and antibiotic resulted in regenerated plants.This study established the optimal conditions for immature embryo callus tissue induction in maize.展开更多
基金supported by the Fundamental Research Funds for the Central Universities of China(2572018BW02)the National Natural Science Foundation of China (31400535 and 31570596)+1 种基金the Innovation Project of State Key Laboratory of Tree Genetics and Breeding (2016C01)the National Key R&D Program of China (2017YFD0600600)。
文摘Somatic embryogenesis of Fraxinus mandshurica has the problems of low somatic embryo(SE) yield,unsynchronized SE development,and a high percentage of deformed SEs.We aimed to improve F.mandshurica SE production by synchronizing SE development,improving SE quality,and inducing root formation to obtain complete regenerated plants.Cotyledons of immature zygotic embryos of F.mandshurica were induced to form callus and then SEs.The SE induction percentage from explants differed among 32 mother trees,and the one with the highest SE induction percentage(29.8%) was used for further experiments.The highest callus induction percentage was94.2% on 1/2-strength Murashige and Skoog medium(MS1/2)supplemented with 0.15 mg·L^(-1) naphthalene acetic acid.The highest callus proliferation coefficient(240.5) was obtained on McCown's Woody Plant Medium containing 0.1 mg·L^(-1)6-benzyl adenine and 0.15 mg·L^(-1) 2,4-dichlorophenoxyacetic acid.The highest number of SEs(1020.5 g~(-1) fresh weight) was obtained on MS1/2 medium supplemented with1 mg·L^(-1) 6-benzyladenine.The highest number of cotyledon embryos(397/g fresh weight) was obtained by incubating materials on medium containing 1 mg·L^(-1) abscisic acid and then applying a drying treatment.The cotyledon embryos were milky white,uniformly sized(average length 4.7 mm),and 80% of them were normal.The SE rooting percentage on 1/2 MS medium containing 0.01 mg·L^(-1) NAA was 37.5%.Overall,the germination percentage of SEs was 26.4%,and complete regenerated plants were obtained after transplanting and acclimation.These results provide more possibilities for the preservation and breeding of F.mandshurica.
文摘Adventitious shoots were successfully regenerated from hypocotyl explants of in vitro cultures of Euonymus japonicus Cu zhi. Hypocotyl slices were cultured on Murashige and Skoog (MS) and B5 basal medium supplemented with varied concentration of different plant growth-regulators, e.g., α-naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA) in combination with 6-benzylaminopurine (6-BA) and kinetin. The study showed that shoots could be directly regenerated from hypocotyl explants without the intervening callus phase; MS medium was more suitable for adventitious shoots regeneration. The ability of hypocotyls segments to produce shoots varied depending upon their position on the seedlings. The highest regeneration rate was obtained with hypocotyl segments near to the cotyledon cultured on MS basal medium supplemented with 1.5 mg L^-1 6-BA and 0.05 mg L^-1 NAA (63.64%). The regenerated shoots were readily elongated on the same medium as used for multiplication and rooted on half-strength MS basal medium supplemented with 1.0 mg L^-1 IBA and 100 mg L^-1 activated carbon. After being transferred to greenhouse conditions, 96% of the plantlets were successfully acclimatized. This regeneration system is applied for genetic transformation now.
文摘In this paper,we describe briefly an efficientculture procedure for micro-propagation of riceregeneration plants.The procedure consists ofthe following steps: 1.Preparation of materials Calli wereinduced from mature seeds of an indica rice lineG67 by culturing the husked and disinfectedseeds on agar medium,consisting of Nbasalelements,3% sucrose,1000mg/L proline,and 32mg/L 2,4-D.After one month's in- duction culture and 3 wk subculture,compactand nodular calli were picked out and trans- ferred into liquid medium for suspension cul-tures.The liquid medium contained the same
文摘The success for genetic transformation of maize (Zea mays L.) is highly related to genotype of target material. A few model varieties can be induced into type Ⅱ callus, which can be easily transformed with high regeneration frequency. However, most of cultivars could be only induced into type Ⅰ callus, which is difficult to be transformed with low regeneration. Thus, studying on the conditions of induction and transformation for type Ⅰ callus will show great importance for improving elite of maize directly with genetic engineering. Bacillus thuringiensis toxin protein (cry1Ac3) gene was successfully delivered into type Ⅰ calli of two elite inbred lines of maize, 340 and E28, via particle bombardment in this work. Fertile transgenic corn plants were obtained through phosphinothricin (PPT) or hygromycin B (HygB) selection, and the results of PCR, Southern blot assay and ELISA showed that foreign genes had been integrated into maize genome and expressed. In the meantime, strong resistance of some transgenic plants to corn borer was showed through bioassay. In addition, the comparison of selective effect between PPT and HygB showed that PPT, as a selective agent, was better than HygB for the growth and regeneration of resistant calli.
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 "863" High Tech Project of China (2001AA241121-10) Natural Science Foundation of Yunnan Province (2005C0023Q)~~
文摘An in vitro shoot regeneration procedure was developed in pepper ( Capsicum annuum L. ) cytoplasmic male sterility (CMS) lines 9704A and 8214A using cotyledon as explant. The callus and bud cluster derived from cotyledon tissue explants were proliferated on Murashige and Skoog (MS) medium supplemented with different combinations of 6-benzladenine (6-BA), indole-3-acetic acid (IAA), gibberellic acid (GA3) and silver nitrate (AgNO3). From the formula of MS appended with 5.0 mg/L 6-BA, 1.0 mg/L IAA and 5.0 mg/L AgNO3, for the explants callus and bud cluster, the maximum differentiation rates ( respectively 100.0% and 58.3% ) and average number of adventitious bud from each explant (respectively 18.8 and 13.2) were obtained. The optimum medium combination for the elongation of adventitious bud was determined to be: MS + 3.0 mg/L 6-BA + 1.0 mg/L IAA + 5.0 mg/L AgNO3 + 2.0 mg/L GA3, from which the elongation rates of buds from callus and bud cluster were both 100%, and the average number of per explant adventitious bud number reached 6.3 and 5.8, respectively. And all the elongated shoots were successfully rooted on half-strength MS medium supplemented with 0.3-0.5 mg/L IAA.
基金Supported by Natural Science Foundation of Guangxi Province(Guikezi 0991096)~~
文摘[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.
基金supported by the National Natural Science Foundation of China (30971776)the National Transgenic Specialized Research Program of China (2008ZX08010-004)
文摘Wheat, one of the most important food crops, has been extensively studied with respects to plant regeneration and transformation employing the immature embryos as recipient tissues. However, the transformed tissues often become severely necrotic after co-cultivation with Agrobacterium, which is one of the major obstacles in gene delivery. In this study, wheat varieties CB037, Kenong 199, Xinchun 9, Lunxuan 987, and Shi 4185 showed desirable culture potential or high infection ability in Agrobacterium-mediated transformation. Similarly, optimal regeneration conditions were determined by testing their ability to inhibit the cell necrosis and cell death phenotype. Two auxins of 2,4-dichlorophenoxyacetic acid (2,4-D) and 3,6-dichloro-o-anisic acid (dicamba) were evaluated for highly significant effect on both callus and plantlet production, although they were genotype-dependent in wheat. Substitution of 2,4-D by dicamba enhanced the growth and regeneration ability of callus from the immature embryos of most genotypes tested. The callus growth state couldn’t be modified by adding antioxidants such as ascorbic acid, cysteine, and silver nitrate or organic additives such as thiamine HCl and asparagine to the media. On the contrary, the best tissue statement and plant regeneration was achieved by employing the media containing the simplest MS (Murashige and Skoog) components and dicamba without organic components and vitamins. Thereby, our results are thought to inhibit wheat cell necrosis effectively and suggested to be used for more wheat genotypes.
文摘To reveal the suitability of using mature embryos as an explant source in wheat tissue culture, mature embryos from eight common wheat cultivars (Triticum aestivum L. cv.) were cultured with or without endosperm to test their efficiency of callus induction and plant regeneration. When embryos were cultured together with endosperm (endosperm-supported culture, ES), the percentage of callus induction was significantly lower than that when embryos were cultured in the absence of endosperm (non-endosperm-supported culture, NES). This pattern was evident in most genotypes, regardless of whether 2 or 8 mg L^-1 2,4-D was added in the NES culture. However, in ES culture, more induced calli were differentiated into distinct green spots and they further developed into plantlets. Thus, more plants were regenerated in ES culture than in the NES treatment. Most of the eight tested genotypes showed a significant difference in callus induction rate and plantlet regeneration in both ES and NES cultures. In addition, the enzymatic activity of oxalate oxidase in the callus of ES culture condition was obviously higher than that in the callus of NES culture condition, suggesting that the activity of oxalate oxidase may be a parameter for selection of calli with potential for plantlet regeneration. These results indicate that wheat mature embryos are valuable explants for highly efficient callus induction and plant regeneration, if proper treatment and medium are used.
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.
基金the National Natural Science Foundation of China(30971776)the Transgenic Major Projects,Ministry of Agriculture of China(2011ZX08010-004)
文摘The immature embryos (IEs) of wheat are the most widely used tissues for in vitro culture and genetic transformation due to its high regeneration competency. However, this explant can only be maintained in 4℃ daily cooler for a short period time for its use in plant tissue culture or transformation experiments. This study aimed to investigate the effects of environmental temperature, cryopreservation storage temperature, and heat shock culture (HSC) temperature on the regeneration frequency of wheat IEs. Results indicated that environmental temperature significantly affected the induction of embryonic calli. The optimum total accumulated temperature (TAT) during the time of anthesis and sampling for regeneration of these tissues was around 280℃ for spring wheat type cv. CB037 and approximately 300℃ for winter wheat type cv. Kenong 199. Regeneration ability obviously declined when the highest environmental temperature was over 35℃ for 1 d or a high temperature between 30 and 33℃ lasted for 5 d during anthesis and sampling. This finding was verified by culturing the freshly isolated IEs under different temperatures from 29 to 37℃ in different controlled growth incubators for 5 d; the IEs almost completely lost regeneration ability when the temperature rose to 37℃. Cryopreservation of-20℃ caused the wheat samples lost ability of producing callus or embryonic callus in a few days, and cryopreservation of-10℃ more than 10 d made the regeneration potential of the tissues dramatically declined. Comparatively, the temperature that best maintained high regeneration ability was -5℃, at which the materials can be maintained for around 1 mon. In addition, the preservation of the immature samples at -5 or -10℃ inhibited the direct germination of the IEs, avoiding the embryo axis removing process. Our results are useful for ensuring that field collection and cryopreservation of the wheat IEs are done correctly to enable tissue culture and genetic transformation.
基金supported by the Outstanding Youth Foundation,China (0512001600)the Natural Scientific Foundation of Henan Province,China(0411032200)
文摘To establish a highly efficient plant regeneration system for wheat genetic transformation, the effects of three different concentrations of dicamba and two different sugar types on callus induction and plant regeneration from mature embryo cultures were evaluated. Callus induction and plant regeneration were obtained from mature embryos of two commercial cultivars Zhoumai 18 and Yumai 34 (Triticum aestivum L.) cultured on L3 basal medium. The results showed that the efficiency of mature embryo culture was significantly influenced by the genotypes, sugar types and dicamba concentrations. 4 mg L^-1 dicamba proved the best effective for inducing embryogenic callus and also gave the highest proportion of plants regenerated across the two cultivars. Substitution of maltose by sucrose significantly improved the plant regeneration efficiency in both cultivars. There was a significant interaction between genotype-by-sugar types, and sugar types-bydicamba concentrations. Overall, Zhoumai 18 gave the highest frequency of plant regeneration (82.65%) when dicamba concentration was 4.0 mg L^-1 and with sucrose in initial callus induction. These results will facilitate genetic transformation work with elite wheat.
基金supported by the Natural Science Foundation of Guangdong Province (05300848)Fok Ying Tung Education Foundation (104031)the National Natural Science Foundation of China(30800758)
文摘This research aims at developing a plant regeneration system from leaf and petiole explants of Anthurium andraeanum Hort., thereby establish a foundation for mass production and transformation. Using tissue culture technique, the conditions for callus induction, protocorm-like body (PLB) formation and plant regeneration from leaf explants and petiole of A. andraeanum, such as basal medium and plant growth regulator, were investigated. Totipotent callus was induced on a 1/2-strength MS medium containing 0.90 μmol L^-1 2,4-dichlorophenoxyacetic acid (2,4-D) and 8.88μmol L^-1 N6-benzyladenine (BA). The callus exhibited complete hormone autonomy for growth and differentiation of PLBs. This callus proliferated well and was maintained by subculturing on 1/2 MS medium containing 0.90 μmol L^-1 2,4-D and 4.44 μmol L^-1 BA. On average, 8 protocorm-like bodies could be obtained from a piece of 4 mm callus after being transferred to the 1/2 MS medium with 4.44 μmol L^-1 BA after 8 wk of culture. The regenerated PLBs formed shoots and roots on 1/2 MS medium. After 24 wk of culture on these medium, well-developed plantlets for potting were produced. An efficient micropropagation method was established for indirect PLB formation and plant regeneration from leaf and petiole ofA. andraeanum.
文摘An improved protocol has been developed for somatic embryogenesis and plant regeneration of recalcitrant cotton cultivars. High callus frequencies and embryogenic tissue were developed in MSB medium supplemented with gradient concentrations of KT and 2,4-D, their concentration decreasing from 0.1 to 0.01 mg·L^-1. Somatic embryos were successfully incubated in 1/2 macronutrient MSB suspension supplemented with 0.5 g· L^-1 glutamine and 0.5 g·L^-1 asparagine. Decrease in macronutrient concentration of MSB significantly alleviated browning and was beneficial to suspension cells. Transformation of somatic embryos into plants was induced in MSB medium supplemented with 3% sucrose, 0.5 g·L^-1 glutamine, 0.5 g·L^-1 asparagine, and 6.0 g·L^-1 agar. The effect of sucrose as carbohydrate was better than that of glucose for plant germination. Using this protocol, regenerated plantlets from the CCRI521 and Zhongzhi86-6 reached to as much as 19.6 and 18.5% somatic embryos, respectively.
基金financially supported in part by the National Key Project for Tansgenic Study, Ministry of Agriculture of China(2011ZX08010-004)
文摘The regeneration rate of wheat immature embryo varies among genotypes, howbeit many elite agriculture wheat varieties have low regeneration rates. Optimization of tissue culture conditions and attempts of adding signal molecules are effective ways to increase plant regeneration rate. Inter-culture is one of ways that have not been investigated in plant tissue culture. Moreover, the use of arabinogalactan proteins (AGPs) and hydrogen peroxide (H202) have been reported to increase regeneration rate in a few plant species other than wheat. The current research pioneeringly uses inter-culture of immature embryos of different wheat genotypes, and also investigates impacts of AGP and H2O2 on the induction of embryogenic calli and plant regeneration. As a result, high-frequency regeneration wheat cultivars Kenong 199 (KN 199) and Xinchun 9 (XC9), together with low-frequency regeneration wheat line Chinese Spring (CS), presented striking increase in the induction of embryogenic calli and plant regeneration rate of CS through inter-culture strategy, up to 52.19 and 67.98%, respectively. Adding 50 to 200 mg L-1 AGP or 0.005 to 0.01‰ H2O2 to the callus induction medium, enhanced growth of embryogenic calli and plant regeneration rate in quite a few wheat genotypes. At 50 mg L-1 AGP application level in callus induction medium plant regeneration rates of 8.49,409.06 and 283.16% were achieved for Jimai 22 (JM22), Jingdong 18 (JD18) and Yangmai 18 (YM18), respectively; whereas at 100 mg L-1 AGP level, CS (105.44%), Chuannong 16 (CN16) (80.60%) and Ningchun 4 (NC4) (62.87%) acted the best. Moreover CS (79.05%), JM22 (7.55%), CN16 (101.87%), YM18 (365.56%), Yangmai 20 (YM20) (10.48%), and CB301 (187.40%) were more responsive to 0.005 %o of H2O2, and NC4 (35.37%) obtained the highest shoot regeneration rates at 0.01%o of H2O2. Overall, these two methods, inter-culture and AGP (or H2O2) application, can be further applied to wheat transgenic research.
基金The authors acknowledge the financial support by the National Natural Science Foundation of China(002002)
文摘An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growthregulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation isbeneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formationefficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAPand 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds perinternodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and weretransferred to the soil.
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 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.
基金supported by a grant from the Bill Melinda Gates FoundationNational Institute of Food and Agriculture of the United States Department of Agriculture for support (Award number 2013-33522-21091)
文摘Switchgrass is native to the tallgrass prairie of North America. It is self-incompatible and has varied ploidy levels from diploid(2x) to dodecaploid(12x) with tetraploid and octoploid being the most common. The high yielding potential and the ability to grow well in marginal lands make switchgrass an ideal species as a dedicated biomass producer for lignocellulosic ethanol production. Genetic transformation is an important tool for studying gene function and for germplasm improvement in switchgrass, the genome of which has been sequenced recently. This paper intends to provide a comprehensive review on plant regeneration and genetic transformation in switchgrass. We first reviewed the effect of explants, basal medium and plant growth regulators on plant regeneration in switchgrass, which is a prerequisite for genetic transformation. We then reviewed the progresses on genetic transformation with either the biolistic or Agrobacterium-mediated method in switchgrass, and discussed various techniques employed to improve the transformation efficiency. Finally we reviewed the recent progresses on the use of genetic transformation in improving biomass quality such as the reduction of lignin, and in increasing biomass yield in switchgrass. We also provided a future perspective on the use of new genome editing technologies in switchgrass and its potential impact on regulatory processes.
文摘Morus alba(white mulberry) mesophyll protoplasts were isolated from leaves of 30-45 day old sterile shoots,with protoplast yields of 2.5 x 107 g-1/F.W. after purification. The protoplasts were cultured in a modified K8P liquid medium containing 0.2 mg/L 2,4-D(2,4- Dichlorophe-noxy acetic acid), 1 mg/L NAA(Naphthyl acetic acid) and 0.5 mg/L BA(6-benzylaminopurine). A low plating density (5 x 104/ml) proved to be favourable to the division of protoplast-derived cells. The first divisioll occurred 4 days after culture, and the division frequency reached 24% at 10 days. A number of cell colonies and microcalli formed in 6 weeks. The microcalli were transferred onto MSB medium with 0.5 mg/L NAA and 0.5 mg/L BA for further proliferation. Shoot formation was initiated when the calli of 3-4 mm in size were transferred onto MSB differentiation medium with 0.1 mg/L NAA and 1 mg/L BA. The frequency of shoot formation was 35%. The shoots of 4-5 cm in height were excised from the callus and rooted on half strength MS medium with 0.5 mg/L IBA and 0.1 mg/L BA. After transplantation into pots, the regenerated plants grew vigorously in the phytotron.
基金This research was funded by Jilin province science and technology research projects(20170204005NY)Jilin Science and Technology Development Plan Major Science and Technology R&D Project(20180201029NY)+2 种基金Jilin Province Science and Technology Development Plan Project(20190802012ZG)Jilin Province Natural Science Foundation(20190201168JC)a thirteenth five-year plan for the Education Department of Jilin Province(JJKH20180661KJ)were jointly funded.
文摘This research uses the immature embryos of inbred maize lines(GSH9901,Hi01,Hi02,and Chang 7-2)as receptor materials to establish the callus induction system.These inbred lines provide the receptor materials for the genetic regeneration of maize and the verification of the genetic functions of maize.The factor experiment and orthogonal experiments were used to investigate the impacts of different genotypes,immature embryo size,shield orientation,2,4-D concentration,proline concentration,and folic acid concentration on the induction rate of embryogenic callus tissue.A sensitivity experiment testing glyphosate(Bar)and an antibiotic(Cefotaxime sodium)were also conducted.The results indicate that the immature embryos of inbred maize line GSH9901 were the most effective for callus tissue induction,and the immature embryos with a length of 1.6-2.0 mm produce the best result.The upward shield face is more successful for the formation of induced callus.Using orthogonal analysis,we found that the optimal combination for the induction system was A_(3)(2,4-D concentration 0.25 mg mL^(-1)),B_(1)C_(3)(proline concentration 0.8 mg mL^(-1)),and D 2(folate Concentration 0.5 mg mL^(-1))and the induction rate reached 84%.We found that cold storage at 4℃ for 1 d is more conducive for the formation of embryogenic callus than the other treatments tested.The sensitivity experiment for callus tissue screening revealed the critical concentration of glyphosate to be 10 mg ml^(-1),and the critical concentration of antibiotic is 250 mg ml^(-1).Using this combination of glyphosate and antibiotic resulted in regenerated plants.This study established the optimal conditions for immature embryo callus tissue induction in maize.