In the 1970s and 1980s, United States Department of Energy conducted numerous studies on the fabrication of nuclear fuel particles using the internal gelation process[1], the internal gelation process is an advanced p...In the 1970s and 1980s, United States Department of Energy conducted numerous studies on the fabrication of nuclear fuel particles using the internal gelation process[1], the internal gelation process is an advanced production process for nuclear fuels. Recently, we had used these lessons learned on the internal gelation process to prepare quantities of uranium dioxide kernels of uniform sizes. This paper discusses the whole efforts of experimental processes.展开更多
Michelia macclurei Dandy is a significant tree species that has extensive cultivation for forestry and horticulture purposes in southern China,owing to its economic and practical importance.Light quality influences pl...Michelia macclurei Dandy is a significant tree species that has extensive cultivation for forestry and horticulture purposes in southern China,owing to its economic and practical importance.Light quality influences plantlet growth and development during tissue culture.However,the growth characteristic and molecular regulation of M.macclurei under different light quality conditions are not well understood yet.In this study,we investigated the morphological,chlorophyll content,and transcriptomic responses of M.macclurei plantlets under different light-emitting diode(LED)qualities,including white,blue,and red light.The results showed that blue light significantly increased plant height(21.29%)and leaf number(18.65%),while red light decreased plant height and leaf number by 7.53%and 16.49%,respectively.In addition,the plantlets’chlorophyll content and etiolation rate were significantly reduced by blue and red light quality compared to white light.Compared to white light,blue light had a negative effect,leading to decreased rooting rate(64.28%),root number(72.72%),and root length(75.86%).Conversely,red light had a positive effect,resulting in increased rooting rate(24.99%),root number(109.58%),and root length(72.72%).Transcriptome analysis identified 54 differentially expressed genes(DEGs)in three groups that consisted of blue light vs.white light(BL-vs-WL),red light vs.white light(RL-vs-WL),and red light vs.blue light(RL-vs-BL).Specifically,21,7,and 41 DEGs were identified in the three groups,respectively.The DEGs found in the RL-vs-WL and BL-vs-WL groups were involved in plant hormone signaling,nitrogen metabolism,and phenylpropanoid biosynthesis pathways,which suggests that M.macclurei plantlets adapt to the changes of light quality via modulating gene expression.Overall,our study provides valuable insights for understanding the molecular and morphological responses of M.macclurei plantlets under different light qualities.展开更多
Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. ...Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.展开更多
The effect of La 3+ and Eu 3+ on the rooting of Eriobotrya japonica Lindl. plantlet in vitro was studied with adding La 3+ and Eu 3+ to the rooted medium. The rooting rate, the number of root and the lengt...The effect of La 3+ and Eu 3+ on the rooting of Eriobotrya japonica Lindl. plantlet in vitro was studied with adding La 3+ and Eu 3+ to the rooted medium. The rooting rate, the number of root and the length of root were studied after transplanting 20 d. The activity of peroxidase, nitrate reductase and fresh weight of roots were determined after transplanting 44 d. The results show that the optimum concentration range of La 3+ (1.0~3.0 μmol·L -1), Eu 3+ (2.0~3.0 μmol·L -1) in the rooted medium can increase the rooting rate and the fresh weight of roots, and promote the length of root and raise the activities of peroxidase and nitrate reductase significantly. La 3+ has more effect in improving the rooting rate, root length and the activities of peroxidase and less effect in promoting root fresh weight and the activities of nitrate reductase than Eu 3+.展开更多
Objective:To study callus induction from different explants(internode,leaf,root)and in vitro plantlets propagation from medicinally important plant Achyranthes aspera L.Methods:Sterilized explants were prepared by uni...Objective:To study callus induction from different explants(internode,leaf,root)and in vitro plantlets propagation from medicinally important plant Achyranthes aspera L.Methods:Sterilized explants were prepared by uning 0.1%HgCl_2 and 0.5%Bavistin and callus was obtained when cultured onto Murashige Skoog's(MS)medium by using different concentrations and combination of 2,4-D.NAA.BAP,IAA,IBA with 3%sucrose and 0.8%agar.Induced callus was immediately transferred to MS medium containing at different concentrations of phytohormones for shootlets and rootlets induction respectively.Results:Sterilization treatment of 0.1%HgCl_2.for 2-3 min and Bavistin 0.5%for 10-12 min showed the highest percentage of asepsis and survival rate.Maximum induction of callus was obtained from a combination of 2.0 mg/L 2,4-D and 0.5 mg/L NAA from leaf.Highest shootlets number(4.83±0.l7)and length(3.8±0.16)cm were observed on full strength MS medium when fortified with BAP 4.0 mg/L and KIN 0.5 mg/L.Concerted efforts of BAP 10 mg/L and NAA 0.5 mg/L on full strength MS medium showed highest leaf number(6.77±0.94).In vitro raised shoots were allowed to root on different strengths of MS medium fortified with IAA and IBA at different concentrations.Experimentally,3.0 mg/L IBA was enabled to induce maximum rootlets number(10.0±9.82)on full strength MS medium.Afterwards,regenerated shoots with well developed roots were successfully subjected to hardening process and were acclimatized.The survived plantlets showed 66.67%survival frequency without any morphological abnormality.Conclusions:The results demonstrated that different explants were good source of callus induction,morphology analysis as well as indirect plantlets regeneration.展开更多
Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the m...Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the minituber production after transplanting. With 100 μmol m^-2s^-1 total photosynthetic photon flux density(PPFD), a light spectrum study of 100% red light emitting diodes(LEDs) light spectrum(RR), 100% blue LEDs light spectrum(BB), 65% red+35% blue LEDs light spectrum(RB), and 45% red+35% blue+20% green LEDs light spectrum(RBG) providing illumination at the in vitro cultured stage of potato plantlets for 4 weeks using fluorescent lamp as control(CK) was performed to investigate the effects of LEDs light spectrum on the growth, leaf anatomy, and chloroplast ultrastructure of potato plantlets in vitro as well as the minituber yield after 2 months transplanting in the greenhouse. Compared to CK, RB and RBG promoted the growth of potato plantlets in vitro with increased stem diameter, plantlet fresh weight, plantlet dry weight, and health index. Furthermore, BB induced the greatest stem diameter as well as the highest health index in potato plantlets in vitro. Root activity, soluble protein, and free amino acid were also significantly enhanced by BB, whereas carbohydrates were improved by RR. In addition, thickness of leaf, palisade parenchyma and spongy parenchyma was significantly increased by BB and RBG. Chloroplasts under BB and RBG showed well-developed grana thylakoid and stroma thylakoid. Unexpectedly, distinct upper epidermis with greatest thickness was induced and palisade parenchyma and spongy parenchyma were arranged neatly in RR. After transplanting in the greenhouse for 2 months, potato plantlets in vitro from BB, RB, and RBG produced high percentage of large size tuber. BB improved fresh and dry weights of the biggest tuber but decreased tuber number per plantlet. In addition, RBG increased tuber number as well as tuber fresh and dry weight slightly. Our results suggested monochromatic blue LEDs as well as combined red, blue or/and green LEDs light spectrum were superior to fluorescent lamp spectrum in micro-propagation of potato plantlets. Therefore, the application of RBG was suitable;BB and RB could be used as alternatives.展开更多
As the energizing and therapeutic effects of infusions of mate(Ilex paraguariensis A.St.-Hil)leaves are increasingly recognized,rising global consumption is also increasing the demand for plantlets with high genetic a...As the energizing and therapeutic effects of infusions of mate(Ilex paraguariensis A.St.-Hil)leaves are increasingly recognized,rising global consumption is also increasing the demand for plantlets with high genetic and morphological qualities.Mini-cuttings are an alternative for clonal plantlets;however,more details are needed on factors that affect the success of this technique.Here,toward maximizing production,we evaluated adventitious rooting competence of mini-cuttings of different sizes and the morphophysiological quality of the resultant plantlets.Small(one bud;length up to 2.5 cm),medium(multiple buds;length 2.6–5.0 cm),and large(multiple buds;length 5.1–10.0 cm)mini-cuttings were planted in a mixture of commercial substrate,vermiculite,and coarse sand(1:1:1 v:v:v),grown in a humidity chamber,then evaluated after 45,60,75,and 90 days for survival,percentage of callus and shoot formation,number and length of shoots,percentage of rooted cuttings,and number and length of roots.Any rooted mini-cuttings were then cultivated in commercial substrate and subsurface soil(2:1 v:v)and evaluated after 30,60,90 and 120 days of cultivation for morphophysiology of the plantlets,percentage of survival,number of leaves,shoot height,stem diameter,and ratio of shoot height to stem diameter.After 120 days,the plantlets were evaluated for the ratio of shoot and root dry mass,total length,surface area,total volume,and mean diameter of roots and Dickson quality index.Adventitious rooting of the mini-cuttings and the morphophysiological quality of the plantlets were not influenced by the size of the vegetative propagule.Therefore,single-bud mini-cuttings have similar adventitious rooting competence,and result in plantlets with adequate morphophysiological quality,based upon leaf development,shoot height,stem diameter and length,and surface area,volume and diameter of roots.Single-bud mini-cuttings up to 2.5 cm long can thus be used to maximize production of mate plantlets by mini-cuttings.展开更多
Litchi chinensis sonn.) ranks second after mango amongst the most important fruit crops cultivated worldwide. Litchi is a very valuable crop throughout the world because it is a table fruit and wines are also produced...Litchi chinensis sonn.) ranks second after mango amongst the most important fruit crops cultivated worldwide. Litchi is a very valuable crop throughout the world because it is a table fruit and wines are also produced from it. The existing cultivars are highly polyploidy and heterozygous in nature. It is propagated through air layering and marcottage methods and storability is very low. Synthetic seeds can be stored for a long time and its genetic constitution could remain the same. For germplasm maintenance and clonal propagation, synthetic seeds can be used. Somatic embryogenesis has been reported from anther or embryogenic suspension culture in various species of litchi. Regeneration via organogenesis and somatic embryogenesis from zygotic embryos has also been reported in certain species. Developing a methodology for getting somatic embryogenesis with a high frequency from zygotic embryos which is available once in a year, would be particularly useful for genetic improvement of litchi. Cotyledonary stage somatic embryos developed from zygotic embryos were encapsulated in 2% alginate gel. The encapsulated somatic embryos (ESEs) germinated successfully on 0.7% agar medium containing 3% sucrose concentration in NN basal medium (half strength of major and minor salts) with 1 mg·l<sup>-1</sup> of gibbrellic acid. Percentage germination and plantlet development for ESEs was higher than that of non encapsulated embryos (NSEs). In comparison to different hormones, gibberellic acid has a significant influence on the germination rate of ESEs after one week of dehydration was seen maximum at 9% sucrose and abscisic acid (1 mg·l-1</sup><sup></sup>) in half strength of major and minor salts in Nitsch and Nitsch medium resulting in extended storage up to 90 days without loss in germination potential and capability to regenerate into plantlets. Normally developed plantlets regenerated from ESEs were successfully adapted to soil to obtain a full grown plant.展开更多
Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato ...Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.展开更多
Tissue culture of Antirrhium majus was experimented by using the tip of shoots as the explants, and comparing the effects of NAA, IAA and 2, 4-D on the formation of adventitious buds. The results indicated that the ef...Tissue culture of Antirrhium majus was experimented by using the tip of shoots as the explants, and comparing the effects of NAA, IAA and 2, 4-D on the formation of adventitious buds. The results indicated that the effect of NAA was the best for the formation of adventitious buds, 5.0, 7.0, 9.0, 11.0, 13.0 mg/L BA combinatcd with 0.1, 0.5, 1.0, 1.5, 2.0 mg/L NAA respectively. The results show that combinations of the concentrations of BA 7.0-9.0 mg/L and NAA 0.1-0.5 mg/L were advantageous to the regeneration of buds and NAA was very important for callus growth.展开更多
The effect of NdCl_3 on the rooting and nitrogen metabolism of loquat in vitro was studied when NdCl_3 was added to the rooted medium. The results show that 0.4 μmol·L^(-1) NdCl_3 in the rooted medium can obviou...The effect of NdCl_3 on the rooting and nitrogen metabolism of loquat in vitro was studied when NdCl_3 was added to the rooted medium. The results show that 0.4 μmol·L^(-1) NdCl_3 in the rooted medium can obviously increase the rooting rate, length of root and fresh weight of roots, and enhance the activities of nitrate reductase, glutamine synthetase, glutamate dehydrogenase in the root system and in the leaves. The transformation of NO_3^- to NH_4^+ in root system and leaves are promoted and the nitrogen metabolism is accelerated with 0.4 μmol·L^(-1) NdCl_3 treatment.展开更多
Poor adventitious root formation is a major obstacle in micropropagation and in conventional propagation. The effects of LaCl_3 on root growth and deferring the root ageing of peach plantlet in vitro were investigated...Poor adventitious root formation is a major obstacle in micropropagation and in conventional propagation. The effects of LaCl_3 on root growth and deferring the root ageing of peach plantlet in vitro were investigated. The results show that the optimum concentration of LaCl_3 (2.5 μmol·L -1) in the rooted medium can significantly increase the rooting rate, the root length and the fresh weight, promote the activities of superoxide dismutase (SOD); catalase (CAT) and peroxidase (POD) and decrease the production rate of O_2 ·-, the malondialdehyde (MDA) contents and the plasma membrane permeability. There are important theory meaning and practical value in applying LaCl_3 in the rooting medium to raise the rate of rooting and transplant for stone fruit tree.展开更多
The effect and the action mechanism of lanthanum on GF_(43) plantlet in vitro were studied. The results of experiments show that root growth rate and dry weight of GF_(43) by LaCl_3 treatments increase. The activities...The effect and the action mechanism of lanthanum on GF_(43) plantlet in vitro were studied. The results of experiments show that root growth rate and dry weight of GF_(43) by LaCl_3 treatments increase. The activities of antioxidant enzymes in root system such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) apparently enhance. Moreover ·O^-_2 and malond ialdehyde (MDA) contents and cell membrane permeability of GF_(43) are decreased by LaCl_3. The relatively stable membrane structure of cell could also be maintained and the root ageing of GF_(43) plantlet in vitro delays.展开更多
In order to isolate and clone water-stress-responsive genes, total RNA was extracted from water-stressed plantlets regenerated in vitro of Populus hopeiensis using a QIAGEN RNeasy Plant Mini Kit. CDNA, synthesized by ...In order to isolate and clone water-stress-responsive genes, total RNA was extracted from water-stressed plantlets regenerated in vitro of Populus hopeiensis using a QIAGEN RNeasy Plant Mini Kit. CDNA, synthesized by LD-PCR with the SMART cDNA Library Construction Kit, was in vitro packaged into a phage λTriplEx2 vector. The resulting primary library and amplified library have a titer of 1.68×10^6 and 1.69×10^9 pfu·mL^-1 respectively. The combination ratio reached 98.8% and the average size of inserts was about 800 bp. In addition, the percentage of inserted fragments (〉400bp) was approximately 90%. The results indicate that a cDNA library has been successfully constructed.展开更多
文摘In the 1970s and 1980s, United States Department of Energy conducted numerous studies on the fabrication of nuclear fuel particles using the internal gelation process[1], the internal gelation process is an advanced production process for nuclear fuels. Recently, we had used these lessons learned on the internal gelation process to prepare quantities of uranium dioxide kernels of uniform sizes. This paper discusses the whole efforts of experimental processes.
基金funded and supported by Fundamental Research Funds of the Chinese Academy of Forestry,No.CAFYBB2017MB10.
文摘Michelia macclurei Dandy is a significant tree species that has extensive cultivation for forestry and horticulture purposes in southern China,owing to its economic and practical importance.Light quality influences plantlet growth and development during tissue culture.However,the growth characteristic and molecular regulation of M.macclurei under different light quality conditions are not well understood yet.In this study,we investigated the morphological,chlorophyll content,and transcriptomic responses of M.macclurei plantlets under different light-emitting diode(LED)qualities,including white,blue,and red light.The results showed that blue light significantly increased plant height(21.29%)and leaf number(18.65%),while red light decreased plant height and leaf number by 7.53%and 16.49%,respectively.In addition,the plantlets’chlorophyll content and etiolation rate were significantly reduced by blue and red light quality compared to white light.Compared to white light,blue light had a negative effect,leading to decreased rooting rate(64.28%),root number(72.72%),and root length(75.86%).Conversely,red light had a positive effect,resulting in increased rooting rate(24.99%),root number(109.58%),and root length(72.72%).Transcriptome analysis identified 54 differentially expressed genes(DEGs)in three groups that consisted of blue light vs.white light(BL-vs-WL),red light vs.white light(RL-vs-WL),and red light vs.blue light(RL-vs-BL).Specifically,21,7,and 41 DEGs were identified in the three groups,respectively.The DEGs found in the RL-vs-WL and BL-vs-WL groups were involved in plant hormone signaling,nitrogen metabolism,and phenylpropanoid biosynthesis pathways,which suggests that M.macclurei plantlets adapt to the changes of light quality via modulating gene expression.Overall,our study provides valuable insights for understanding the molecular and morphological responses of M.macclurei plantlets under different light qualities.
文摘Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.
文摘The effect of La 3+ and Eu 3+ on the rooting of Eriobotrya japonica Lindl. plantlet in vitro was studied with adding La 3+ and Eu 3+ to the rooted medium. The rooting rate, the number of root and the length of root were studied after transplanting 20 d. The activity of peroxidase, nitrate reductase and fresh weight of roots were determined after transplanting 44 d. The results show that the optimum concentration range of La 3+ (1.0~3.0 μmol·L -1), Eu 3+ (2.0~3.0 μmol·L -1) in the rooted medium can increase the rooting rate and the fresh weight of roots, and promote the length of root and raise the activities of peroxidase and nitrate reductase significantly. La 3+ has more effect in improving the rooting rate, root length and the activities of peroxidase and less effect in promoting root fresh weight and the activities of nitrate reductase than Eu 3+.
基金Supported by Islamic University.Kushtia-7003.Bangladesh(Grant No.IUBT-1108)
文摘Objective:To study callus induction from different explants(internode,leaf,root)and in vitro plantlets propagation from medicinally important plant Achyranthes aspera L.Methods:Sterilized explants were prepared by uning 0.1%HgCl_2 and 0.5%Bavistin and callus was obtained when cultured onto Murashige Skoog's(MS)medium by using different concentrations and combination of 2,4-D.NAA.BAP,IAA,IBA with 3%sucrose and 0.8%agar.Induced callus was immediately transferred to MS medium containing at different concentrations of phytohormones for shootlets and rootlets induction respectively.Results:Sterilization treatment of 0.1%HgCl_2.for 2-3 min and Bavistin 0.5%for 10-12 min showed the highest percentage of asepsis and survival rate.Maximum induction of callus was obtained from a combination of 2.0 mg/L 2,4-D and 0.5 mg/L NAA from leaf.Highest shootlets number(4.83±0.l7)and length(3.8±0.16)cm were observed on full strength MS medium when fortified with BAP 4.0 mg/L and KIN 0.5 mg/L.Concerted efforts of BAP 10 mg/L and NAA 0.5 mg/L on full strength MS medium showed highest leaf number(6.77±0.94).In vitro raised shoots were allowed to root on different strengths of MS medium fortified with IAA and IBA at different concentrations.Experimentally,3.0 mg/L IBA was enabled to induce maximum rootlets number(10.0±9.82)on full strength MS medium.Afterwards,regenerated shoots with well developed roots were successfully subjected to hardening process and were acclimatized.The survived plantlets showed 66.67%survival frequency without any morphological abnormality.Conclusions:The results demonstrated that different explants were good source of callus induction,morphology analysis as well as indirect plantlets regeneration.
基金supported by the National High-Tech R&D Program of China (2013 AA 103005)
文摘Light spectrum plays an important role in regulating the growth and development of in vitro cultured potato(Solanum tuberosum L.) plantlets. The status of potato plantlets at the end of in vitro stage influences the minituber production after transplanting. With 100 μmol m^-2s^-1 total photosynthetic photon flux density(PPFD), a light spectrum study of 100% red light emitting diodes(LEDs) light spectrum(RR), 100% blue LEDs light spectrum(BB), 65% red+35% blue LEDs light spectrum(RB), and 45% red+35% blue+20% green LEDs light spectrum(RBG) providing illumination at the in vitro cultured stage of potato plantlets for 4 weeks using fluorescent lamp as control(CK) was performed to investigate the effects of LEDs light spectrum on the growth, leaf anatomy, and chloroplast ultrastructure of potato plantlets in vitro as well as the minituber yield after 2 months transplanting in the greenhouse. Compared to CK, RB and RBG promoted the growth of potato plantlets in vitro with increased stem diameter, plantlet fresh weight, plantlet dry weight, and health index. Furthermore, BB induced the greatest stem diameter as well as the highest health index in potato plantlets in vitro. Root activity, soluble protein, and free amino acid were also significantly enhanced by BB, whereas carbohydrates were improved by RR. In addition, thickness of leaf, palisade parenchyma and spongy parenchyma was significantly increased by BB and RBG. Chloroplasts under BB and RBG showed well-developed grana thylakoid and stroma thylakoid. Unexpectedly, distinct upper epidermis with greatest thickness was induced and palisade parenchyma and spongy parenchyma were arranged neatly in RR. After transplanting in the greenhouse for 2 months, potato plantlets in vitro from BB, RB, and RBG produced high percentage of large size tuber. BB improved fresh and dry weights of the biggest tuber but decreased tuber number per plantlet. In addition, RBG increased tuber number as well as tuber fresh and dry weight slightly. Our results suggested monochromatic blue LEDs as well as combined red, blue or/and green LEDs light spectrum were superior to fluorescent lamp spectrum in micro-propagation of potato plantlets. Therefore, the application of RBG was suitable;BB and RB could be used as alternatives.
基金supported by the National Council for Scientifi c and Technological Development(CNPq)and the Coordination for the Improvement of Higher Education Personnel(CAPES)of Brazil for scholarships.
文摘As the energizing and therapeutic effects of infusions of mate(Ilex paraguariensis A.St.-Hil)leaves are increasingly recognized,rising global consumption is also increasing the demand for plantlets with high genetic and morphological qualities.Mini-cuttings are an alternative for clonal plantlets;however,more details are needed on factors that affect the success of this technique.Here,toward maximizing production,we evaluated adventitious rooting competence of mini-cuttings of different sizes and the morphophysiological quality of the resultant plantlets.Small(one bud;length up to 2.5 cm),medium(multiple buds;length 2.6–5.0 cm),and large(multiple buds;length 5.1–10.0 cm)mini-cuttings were planted in a mixture of commercial substrate,vermiculite,and coarse sand(1:1:1 v:v:v),grown in a humidity chamber,then evaluated after 45,60,75,and 90 days for survival,percentage of callus and shoot formation,number and length of shoots,percentage of rooted cuttings,and number and length of roots.Any rooted mini-cuttings were then cultivated in commercial substrate and subsurface soil(2:1 v:v)and evaluated after 30,60,90 and 120 days of cultivation for morphophysiology of the plantlets,percentage of survival,number of leaves,shoot height,stem diameter,and ratio of shoot height to stem diameter.After 120 days,the plantlets were evaluated for the ratio of shoot and root dry mass,total length,surface area,total volume,and mean diameter of roots and Dickson quality index.Adventitious rooting of the mini-cuttings and the morphophysiological quality of the plantlets were not influenced by the size of the vegetative propagule.Therefore,single-bud mini-cuttings have similar adventitious rooting competence,and result in plantlets with adequate morphophysiological quality,based upon leaf development,shoot height,stem diameter and length,and surface area,volume and diameter of roots.Single-bud mini-cuttings up to 2.5 cm long can thus be used to maximize production of mate plantlets by mini-cuttings.
文摘Litchi chinensis sonn.) ranks second after mango amongst the most important fruit crops cultivated worldwide. Litchi is a very valuable crop throughout the world because it is a table fruit and wines are also produced from it. The existing cultivars are highly polyploidy and heterozygous in nature. It is propagated through air layering and marcottage methods and storability is very low. Synthetic seeds can be stored for a long time and its genetic constitution could remain the same. For germplasm maintenance and clonal propagation, synthetic seeds can be used. Somatic embryogenesis has been reported from anther or embryogenic suspension culture in various species of litchi. Regeneration via organogenesis and somatic embryogenesis from zygotic embryos has also been reported in certain species. Developing a methodology for getting somatic embryogenesis with a high frequency from zygotic embryos which is available once in a year, would be particularly useful for genetic improvement of litchi. Cotyledonary stage somatic embryos developed from zygotic embryos were encapsulated in 2% alginate gel. The encapsulated somatic embryos (ESEs) germinated successfully on 0.7% agar medium containing 3% sucrose concentration in NN basal medium (half strength of major and minor salts) with 1 mg·l<sup>-1</sup> of gibbrellic acid. Percentage germination and plantlet development for ESEs was higher than that of non encapsulated embryos (NSEs). In comparison to different hormones, gibberellic acid has a significant influence on the germination rate of ESEs after one week of dehydration was seen maximum at 9% sucrose and abscisic acid (1 mg·l-1</sup><sup></sup>) in half strength of major and minor salts in Nitsch and Nitsch medium resulting in extended storage up to 90 days without loss in germination potential and capability to regenerate into plantlets. Normally developed plantlets regenerated from ESEs were successfully adapted to soil to obtain a full grown plant.
基金funded by the Scientific Research Fund of College of Science&Technology,Ningbo University for the Introduction of High-level Talents,China(RC190006)。
文摘Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.
文摘Tissue culture of Antirrhium majus was experimented by using the tip of shoots as the explants, and comparing the effects of NAA, IAA and 2, 4-D on the formation of adventitious buds. The results indicated that the effect of NAA was the best for the formation of adventitious buds, 5.0, 7.0, 9.0, 11.0, 13.0 mg/L BA combinatcd with 0.1, 0.5, 1.0, 1.5, 2.0 mg/L NAA respectively. The results show that combinations of the concentrations of BA 7.0-9.0 mg/L and NAA 0.1-0.5 mg/L were advantageous to the regeneration of buds and NAA was very important for callus growth.
文摘The effect of NdCl_3 on the rooting and nitrogen metabolism of loquat in vitro was studied when NdCl_3 was added to the rooted medium. The results show that 0.4 μmol·L^(-1) NdCl_3 in the rooted medium can obviously increase the rooting rate, length of root and fresh weight of roots, and enhance the activities of nitrate reductase, glutamine synthetase, glutamate dehydrogenase in the root system and in the leaves. The transformation of NO_3^- to NH_4^+ in root system and leaves are promoted and the nitrogen metabolism is accelerated with 0.4 μmol·L^(-1) NdCl_3 treatment.
文摘Poor adventitious root formation is a major obstacle in micropropagation and in conventional propagation. The effects of LaCl_3 on root growth and deferring the root ageing of peach plantlet in vitro were investigated. The results show that the optimum concentration of LaCl_3 (2.5 μmol·L -1) in the rooted medium can significantly increase the rooting rate, the root length and the fresh weight, promote the activities of superoxide dismutase (SOD); catalase (CAT) and peroxidase (POD) and decrease the production rate of O_2 ·-, the malondialdehyde (MDA) contents and the plasma membrane permeability. There are important theory meaning and practical value in applying LaCl_3 in the rooting medium to raise the rate of rooting and transplant for stone fruit tree.
文摘The effect and the action mechanism of lanthanum on GF_(43) plantlet in vitro were studied. The results of experiments show that root growth rate and dry weight of GF_(43) by LaCl_3 treatments increase. The activities of antioxidant enzymes in root system such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) apparently enhance. Moreover ·O^-_2 and malond ialdehyde (MDA) contents and cell membrane permeability of GF_(43) are decreased by LaCl_3. The relatively stable membrane structure of cell could also be maintained and the root ageing of GF_(43) plantlet in vitro delays.
文摘In order to isolate and clone water-stress-responsive genes, total RNA was extracted from water-stressed plantlets regenerated in vitro of Populus hopeiensis using a QIAGEN RNeasy Plant Mini Kit. CDNA, synthesized by LD-PCR with the SMART cDNA Library Construction Kit, was in vitro packaged into a phage λTriplEx2 vector. The resulting primary library and amplified library have a titer of 1.68×10^6 and 1.69×10^9 pfu·mL^-1 respectively. The combination ratio reached 98.8% and the average size of inserts was about 800 bp. In addition, the percentage of inserted fragments (〉400bp) was approximately 90%. The results indicate that a cDNA library has been successfully constructed.