This study developed an efficient in vitro cultivation and propagation sys- tem for an endangered species Kolkwitzia amabilis using nodal segments as ex- plants. Multiple shoots were induced through axillary bud forma...This study developed an efficient in vitro cultivation and propagation sys- tem for an endangered species Kolkwitzia amabilis using nodal segments as ex- plants. Multiple shoots were induced through axillary bud formation. The highest fre- quency of multiple shoot induction was achieved when the nodal segment explants were incubated in Murashige and Skoog (MS) medium supplemented with 4.44 pM 6-benzyladenine (6-BA) in combination with 0.54 μM a-naphthaleneacetic acid (NAA), followed by treatment with 4.44 μM 6-BA in combination with 0.27 μM NAA. Shoot multiplication could be induced in MS medium supplemented with stand-alone 6-BA or 6-BA in combination with indole-3-acetic acid (1.71 μM) or NAA (0.27 or 0.54 μM), with 6-BA and either compound, exhibiting a stronger effect on shoot multiplication. The optimum combination of plant growth regulators for shoot multiplication was 4.44 μM 6-BA with 0.27 μM NAA. The maximum rooting percentage was obtained in a half-strength MS medium supplemented with indole-3-butyric acid alone and in com- bination with NAA and 2,4-dichlorophenoxyacetic acid, but the best combination of plant growth regulators for rooting was 1.48 μM indole-3-butyric acid with 1.08 μM NAA and 0.05 μM 2,4-dichlorophenoxyacetic acid. The rooted shoots were trans- ferred to a greenhouse with a success rate of 100%.展开更多
RAV1 is a novel DNA-binding protein with two distinct DNA-binding domains unique in higher plants,but its role in plant growth and development remains unknown. Using cDNA array,we found that transcription of RAV1 is d...RAV1 is a novel DNA-binding protein with two distinct DNA-binding domains unique in higher plants,but its role in plant growth and development remains unknown. Using cDNA array,we found that transcription of RAV1 is downregulated by epibrassinolide (epiBL) in Arabidopsis suspension cells. RNA gel blot analysis revealed that epiBL-regulated RAV1 transcription involves neither protein phosphorylation/dephosphorylation nor newly synthesized protein,and does not require the functional BRI1,suggesting that this regulation might be through a new BR signaling pathway.Overexpressing RAV1 in Arabidopsis results in a retardation of lateral root and rosette leaf development,and the underexpression causes an earlier flowering phenotype,implying that RAV1 may function as a negative regulatory component of growth and development.展开更多
Salt-affected soils are agricultural and environmental problems on a global scale. Plants suffer from saline stresses in these soils and show nitrogen (N) deficiency symptoms. However, halophytes grow soundly under ...Salt-affected soils are agricultural and environmental problems on a global scale. Plants suffer from saline stresses in these soils and show nitrogen (N) deficiency symptoms. However, halophytes grow soundly under saline conditions. In order to clarify the N nutrition of the halophyte Salicornia bigelovii, it was grown at several N levels (1, 2, 3, and 4 mmol L-1), supplied in the form of NO3 or ammonium (NH4+), under high NaCl conditions (200 mmol L-l). NH4^+- fed plants showed better growth than NO3-fed plants at 1-3 mmol L-1N, and plants in both treatments showed the same growth at 4 mmol L-1 N. Nitrogen contents in NO3-fed plants increased with the N concentrations in solution; competitive inhibition of NO3- absorption by Cl- was observed under lower N conditions. In addition, shoot dry weight was significantly correlated only with shoot N content. Therefore, growth of NO3-fed plants was regulated by N absorption. In contrast, N contents of shoots in NH4+-fed plants did not change with N concentration. Shoot Na content decreased with increasing N concentration, while K content increased. Dry weight was highly correlated only with K content in NH4+-fed plants. These observations indicated that growth of NH4+-fed plants was mainly regulated by K absorption.展开更多
Fruitlet abscission (cherelle wilt) is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants (PGRs...Fruitlet abscission (cherelle wilt) is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants (PGRs) on cacao trees at about 10 weeks before flowering session. The treatment was repeated every three weeks. Both the flowering initiation time and the number of flowers on the treated trees were improved significantly. With the most effective composition, flowers were initiated at 24 days after spraying (DAS), where as the flowering initiation was 11-day later in the controls. At the 35 DAS, the chlorocholine chloride (CCC) 2,000 treatment induced about 20-80 folds more flowers than the controls. Extended observation was made to assess the treatment effect on the fruiting capacity. The treatments were found to improve fruiting ability by increasing the number of fruits set on the trees and shortening the time for fruit setting. At 20 weeks after the first spraying (WAS) there were on average 12.57 fruits per CCC 2,000-treated tree, as opposed to only 4.14 fruits per untreated tree. Analyses of the metabolites content in the flower cushions of the trees indicated that the reproductive growth is significantly correlated with the increased metabolites particularly the reduced sugar. Exogenous addition of sucrose to the PGR treatment gave greater improvement mainly in the fruiting. In conclusion, foliar spray of CCC induces flowering of cacao tress in the field that leads to improve the fruitlets productivity.展开更多
[Objective]As a mosquito-repelling ornamental plant,Pelargonium×Citrosum Vanleenii(P.× Citrosum Vanleenii)is hard to be acquired because of its hybrid background,the paper was to a new regeneration system of...[Objective]As a mosquito-repelling ornamental plant,Pelargonium×Citrosum Vanleenii(P.× Citrosum Vanleenii)is hard to be acquired because of its hybrid background,the paper was to a new regeneration system of(P.× Citrosum Vanleenii).[Method] By studying the influence of plant growth regulators(PGRs)on explant type(leaves and petioles),the optimal combinations of PGRs to maximize SELSs(somatic embryo-like structure)and buds were established.[Result]0.2 mg/L NAA+1.0 mg/L BA was best for LS(leaves segments)and 0.2 mg/L NAA + 1.5 mg/L BAs was best for PS(petioles segments).Cultured plantlets were successfully acclimatized in soil where they grew normally without any morphological variation.Although both LS and PS were usable,the leaf was a better explant for induction of embryogenic calli,somatic embryo-like structures and buds.[Conclusion]This work offered a rapid and efficient system for plant regeneration of P.×Citrosum Vanleenii.展开更多
文摘This study developed an efficient in vitro cultivation and propagation sys- tem for an endangered species Kolkwitzia amabilis using nodal segments as ex- plants. Multiple shoots were induced through axillary bud formation. The highest fre- quency of multiple shoot induction was achieved when the nodal segment explants were incubated in Murashige and Skoog (MS) medium supplemented with 4.44 pM 6-benzyladenine (6-BA) in combination with 0.54 μM a-naphthaleneacetic acid (NAA), followed by treatment with 4.44 μM 6-BA in combination with 0.27 μM NAA. Shoot multiplication could be induced in MS medium supplemented with stand-alone 6-BA or 6-BA in combination with indole-3-acetic acid (1.71 μM) or NAA (0.27 or 0.54 μM), with 6-BA and either compound, exhibiting a stronger effect on shoot multiplication. The optimum combination of plant growth regulators for shoot multiplication was 4.44 μM 6-BA with 0.27 μM NAA. The maximum rooting percentage was obtained in a half-strength MS medium supplemented with indole-3-butyric acid alone and in com- bination with NAA and 2,4-dichlorophenoxyacetic acid, but the best combination of plant growth regulators for rooting was 1.48 μM indole-3-butyric acid with 1.08 μM NAA and 0.05 μM 2,4-dichlorophenoxyacetic acid. The rooted shoots were trans- ferred to a greenhouse with a success rate of 100%.
基金supported by grants from the National Natural Science Foundation of China(No.39889003,30070074,30221002)a National Distinguished Young Scholar Award to Jia Yang LI.
文摘RAV1 is a novel DNA-binding protein with two distinct DNA-binding domains unique in higher plants,but its role in plant growth and development remains unknown. Using cDNA array,we found that transcription of RAV1 is downregulated by epibrassinolide (epiBL) in Arabidopsis suspension cells. RNA gel blot analysis revealed that epiBL-regulated RAV1 transcription involves neither protein phosphorylation/dephosphorylation nor newly synthesized protein,and does not require the functional BRI1,suggesting that this regulation might be through a new BR signaling pathway.Overexpressing RAV1 in Arabidopsis results in a retardation of lateral root and rosette leaf development,and the underexpression causes an earlier flowering phenotype,implying that RAV1 may function as a negative regulatory component of growth and development.
基金Supported by the "Global Center of Excellence for Dryland Science",a project of the Ministry of Education,Science,Culture,Sports and Technology of Japan
文摘Salt-affected soils are agricultural and environmental problems on a global scale. Plants suffer from saline stresses in these soils and show nitrogen (N) deficiency symptoms. However, halophytes grow soundly under saline conditions. In order to clarify the N nutrition of the halophyte Salicornia bigelovii, it was grown at several N levels (1, 2, 3, and 4 mmol L-1), supplied in the form of NO3 or ammonium (NH4+), under high NaCl conditions (200 mmol L-l). NH4^+- fed plants showed better growth than NO3-fed plants at 1-3 mmol L-1N, and plants in both treatments showed the same growth at 4 mmol L-1 N. Nitrogen contents in NO3-fed plants increased with the N concentrations in solution; competitive inhibition of NO3- absorption by Cl- was observed under lower N conditions. In addition, shoot dry weight was significantly correlated only with shoot N content. Therefore, growth of NO3-fed plants was regulated by N absorption. In contrast, N contents of shoots in NH4+-fed plants did not change with N concentration. Shoot Na content decreased with increasing N concentration, while K content increased. Dry weight was highly correlated only with K content in NH4+-fed plants. These observations indicated that growth of NH4+-fed plants was mainly regulated by K absorption.
文摘Fruitlet abscission (cherelle wilt) is a major factor contributing to lower productivity of cacao plantation in Indonesia. An attempt was made to reduce such cherelle wilt by spraying plant growth retardants (PGRs) on cacao trees at about 10 weeks before flowering session. The treatment was repeated every three weeks. Both the flowering initiation time and the number of flowers on the treated trees were improved significantly. With the most effective composition, flowers were initiated at 24 days after spraying (DAS), where as the flowering initiation was 11-day later in the controls. At the 35 DAS, the chlorocholine chloride (CCC) 2,000 treatment induced about 20-80 folds more flowers than the controls. Extended observation was made to assess the treatment effect on the fruiting capacity. The treatments were found to improve fruiting ability by increasing the number of fruits set on the trees and shortening the time for fruit setting. At 20 weeks after the first spraying (WAS) there were on average 12.57 fruits per CCC 2,000-treated tree, as opposed to only 4.14 fruits per untreated tree. Analyses of the metabolites content in the flower cushions of the trees indicated that the reproductive growth is significantly correlated with the increased metabolites particularly the reduced sugar. Exogenous addition of sucrose to the PGR treatment gave greater improvement mainly in the fruiting. In conclusion, foliar spray of CCC induces flowering of cacao tress in the field that leads to improve the fruitlets productivity.
基金Supported by Fund of Jinhua Science Technology Foundation of China(2009-2-02)
文摘[Objective]As a mosquito-repelling ornamental plant,Pelargonium×Citrosum Vanleenii(P.× Citrosum Vanleenii)is hard to be acquired because of its hybrid background,the paper was to a new regeneration system of(P.× Citrosum Vanleenii).[Method] By studying the influence of plant growth regulators(PGRs)on explant type(leaves and petioles),the optimal combinations of PGRs to maximize SELSs(somatic embryo-like structure)and buds were established.[Result]0.2 mg/L NAA+1.0 mg/L BA was best for LS(leaves segments)and 0.2 mg/L NAA + 1.5 mg/L BAs was best for PS(petioles segments).Cultured plantlets were successfully acclimatized in soil where they grew normally without any morphological variation.Although both LS and PS were usable,the leaf was a better explant for induction of embryogenic calli,somatic embryo-like structures and buds.[Conclusion]This work offered a rapid and efficient system for plant regeneration of P.×Citrosum Vanleenii.