Background Thidiazuron(TDZ)is a widely used chemical defoliant in commercial cotton production and is often combined with the herbicide Diuron to form the commercial defoliant mixture known as TDZ·Diuron(T·D...Background Thidiazuron(TDZ)is a widely used chemical defoliant in commercial cotton production and is often combined with the herbicide Diuron to form the commercial defoliant mixture known as TDZ·Diuron(T·D,540 g·L^(-1)suspension).However,due to increasing concerns about the environmental and biological risks posed by Diuron,there is an urgent need to develop safer and more effective alternatives.Jasmonic acid(JA)and its derivatives are key phytohormones in organ senescence and abscission.Results Greenhouse experiments at the seedling stage revealed that Me-JA(0.8 mmol·L^(-1))alone did not induce defoliation.However,its co-application with TDZ(0.45 mmol·L^(-1))at concentrations of 0.6,0.8,and 1.0 mmol·L^(-1)significantly enhanced defoliation efficacy.The most effective combination—TDZ with 0.8 mmol·L^(-1)Me-JA—achieved a 100%defoliation rate at 5 days after treatment(DAT),23.7 percentage points higher than TDZ alone,and comparable to the commercial TDZ·Diuron formulation with equivalent TDZ content.Field trials conducted in Beijing(Shangzhuang),Hebei(Hejian),and Xinjiang(Shihezi)confirmed that the combination of 0.6 mmol·L^(-1)Me-JA with 1.70 mmol·L^(-1)TDZ provided optimal defoliation performance.At 21 DAT,the defoliation rate increased by 13.5–16.3 percentage points compared with TDZ alone.Furthermore,boll opening rates improved by 5.7–12.7 percentage points relative to TDZ-only treatments.Phytohormonal analyses from the Shangzhuang site showed that the combined treatment significantly altered hormone levels in both leaves and petioles.Compared with TDZ alone,the mixture reduced concentrations of auxin(IAA),cytokinins(Z+ZR,iP+iPA,DHZ+DHZR),and gibberellic acid(GA3),while increasing levels of JA,abscisic acid(ABA),and brassinosteroids(BR).These hormonal shifts may underlie the enhanced defoliation observed with the combined treatment.Importantly,the TDZ-Me-JA combination did not adversely affect cotton yield,yield components,or fiber quality.Conclusion The combination of Me-JA and TDZ has a good defoliation effect without affecting crop yield or fiber quality.And it provides a promising foundation for the development of novel,environmentally friendly cotton defoliants.展开更多
A protocol for micropropagation using nodal explants from mature Pinus massoniana trees has been developed. Time of explant collection is crucial for the initial success of aseptic culture. Explants collected in early...A protocol for micropropagation using nodal explants from mature Pinus massoniana trees has been developed. Time of explant collection is crucial for the initial success of aseptic culture. Explants collected in early March gave the highest percentage of explant survival (64.5%) and shoot-forming percentage (52.3%). Thidiazuron (TDZ) concentration significantly influenced shoot formation; 4 mu M TDZ was optimum, with 4.8 shoots produced per explant with a mean length of 7.1 cm after 120 days of culture. Regenerated shoots rooted for 60 days in basic medium with 1 mu M NAA were ready for growth in pots. This is the first report on plantlet regeneration in vitro from mature trees of P. massoniana that provides a reliable method for propagating selected elites.展开更多
Populus species are important resources for industry and in scientific study on biological and agricul- tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar （Populus cil...Populus species are important resources for industry and in scientific study on biological and agricul- tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar （Populus ciliata wall. ex Royle）. The effect of TDZ alone and in combi- nation with adenine and NAA was studied on the regen- eration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glass- houses. After surface sterilization the explants were cul- tured on shoot induction medium. High percentage shoot regeneration （86 %） was recorded on MS medium sup- plemented with 0.004 mg L-1 TDZ and 79.7 mg L-1 adenine. The regenerated shoots for elongation and multi- plication were transferred to MS ＋ 0.5 mg L-1 BAP ＋ 0.2 mg L-1 IAA ＋ 0.3 mg L-1 GA3. Root re- generation from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L-1 IBA. Hi- malayan poplar plantlets could be produced within 2 months after acclimatization in a sterile mixture of sand and soil. We developed a high efficiency plant regeneration protocol from petiole explants of P. ciliata.展开更多
[Objectives]This study was conducted to investigate the application time,concentrations,and combinations of plant growth regulators,aiming to screen suitable concentrations,combinations,and treatment periods for enhan...[Objectives]This study was conducted to investigate the application time,concentrations,and combinations of plant growth regulators,aiming to screen suitable concentrations,combinations,and treatment periods for enhancing the commercial quality of the fruit.[Methods]‘Xiangfei’grape was selected as the experimental material.Treatments were applied at two stages:full bloom and 10-14 d after flowering.Three plant growth regulators,gibberellin(GA 3),forchlorfenuron(CPPU),and thidiazuron(TDZ),were used at different concentrations and in various combinations.The aim was to investigate the effects of different treatments on the seedless rate and fruit quality of‘Xiangfei’grape and to identify the optimal protocol for seedlessness induction in this cultivar.[Results]The optimal treatment protocol was the application of GA 350 mg/L+TDZ 4 mg/L at full bloom,followed by clear water 10-14 d after full bloom.After this combined pre-and post-flowering treatment,a seedless rate of 73%was achieved.The corresponding fruit quality parameters were as follows:single berry weight,17.64 g;longitudinal diameter,28.94 mm;transverse diameter,30.21 mm;fruit firmness,8.41 N/cm_(2);and soluble protein content,0.94 mg/g.Compared with other treatments,this protocol improved berry longitudinal and transverse diameters,fruit firmness,single berry weight,soluble solid content,and soluble protein content in‘Xiangfei’berries.It also altered the fruit shape index,reduced tannin content,and had a minimal impact on vitamin C content.[Conclusions]This study can provide a theoretical basis and technical reference for the seedlessness production of‘Xiangfei’grape.展开更多
Thidiazuron(TDZ)is used for the expansion of fruits,but excessive levels of TDZ lead to a decline in fruit quality.The appropriate concentration of TDZ for mango expansion without a decline in quality is not clear.In ...Thidiazuron(TDZ)is used for the expansion of fruits,but excessive levels of TDZ lead to a decline in fruit quality.The appropriate concentration of TDZ for mango expansion without a decline in quality is not clear.In the present study,four different concentrations(5,10,15,and 20 mg/L)of TDZ were applied via spraying on mango plants,and several physiological and biochemical indicators were measured.The results showed that TDZ treatment significantly increased mango fruit size and single-fruit weight.In mango fruit,TDZ treatment decreased the disease index,delayed the increase in the malondialdehyde and H2O2 content,and maintained firmness and antioxidant capacities at a relatively high level during postharvest storage.At the same time,TDZ treatment delayed the decrease in the giberellin,indoleacetic acid and jasmonic acid content in mango,and reduced the accumulation of abscisic acid and ethylene.These trends are consistent with TDZ treatment leading to extension of the shelf life of mango.Furthermore,ethylene biosynthesis,signal transduction,and cell wall dismantling-related genes were investigated.The results indicated that the expression of the MiACS,MiETR2,MiERF113,MiERF010,MiERF054,MiEXP,MiPG14,MiPG21,MiCEL,and MiPEL genes in mango was inhibited under TDZ treatment compared with the control.In summary,TDZ treatment can significantly increase the size and weight of mango fruit and can extend its shelf life.The most suitable concentration is 10–15 mg/L TDZ,which will not affect the quality of mango fruit.展开更多
The effectiveness of thidiazuron（TDZ）on adventitious bud and shoot formation from leaves of Robinia pseudoacacia was tested in combination with naphthaleneacetic acid （NAA）or 2,4-dichiorophenoxyacetic acid （2,4-D...The effectiveness of thidiazuron（TDZ）on adventitious bud and shoot formation from leaves of Robinia pseudoacacia was tested in combination with naphthaleneacetic acid （NAA）or 2,4-dichiorophenoxyacetic acid （2,4-D）,With the increasing of TDZ level,the induction rate of adventitious buds appeared an increasing trend and the highest rate was obtained by the combination of 2mg/L TDZ whth 0.1mg/L NAA.The excessive level of TDZ could induce useless cellae and easily produce hyperhydricity.Inhibition of shoot elongation by TDZ was overcome through transferring shoot cultures to a shoot proliferation medium lacking TDZ orcontaining NAA,benzyladenine （BA）and TDZ.Indole-3-butyric acid （IBA）was used to stimulate the rooting in vitro .Based on the number and length of rooting ,the treatment with 0.5mg/L IBA was the best.展开更多
基金funded by the China Agriculture Research System(CARS–15–16)。
文摘Background Thidiazuron(TDZ)is a widely used chemical defoliant in commercial cotton production and is often combined with the herbicide Diuron to form the commercial defoliant mixture known as TDZ·Diuron(T·D,540 g·L^(-1)suspension).However,due to increasing concerns about the environmental and biological risks posed by Diuron,there is an urgent need to develop safer and more effective alternatives.Jasmonic acid(JA)and its derivatives are key phytohormones in organ senescence and abscission.Results Greenhouse experiments at the seedling stage revealed that Me-JA(0.8 mmol·L^(-1))alone did not induce defoliation.However,its co-application with TDZ(0.45 mmol·L^(-1))at concentrations of 0.6,0.8,and 1.0 mmol·L^(-1)significantly enhanced defoliation efficacy.The most effective combination—TDZ with 0.8 mmol·L^(-1)Me-JA—achieved a 100%defoliation rate at 5 days after treatment(DAT),23.7 percentage points higher than TDZ alone,and comparable to the commercial TDZ·Diuron formulation with equivalent TDZ content.Field trials conducted in Beijing(Shangzhuang),Hebei(Hejian),and Xinjiang(Shihezi)confirmed that the combination of 0.6 mmol·L^(-1)Me-JA with 1.70 mmol·L^(-1)TDZ provided optimal defoliation performance.At 21 DAT,the defoliation rate increased by 13.5–16.3 percentage points compared with TDZ alone.Furthermore,boll opening rates improved by 5.7–12.7 percentage points relative to TDZ-only treatments.Phytohormonal analyses from the Shangzhuang site showed that the combined treatment significantly altered hormone levels in both leaves and petioles.Compared with TDZ alone,the mixture reduced concentrations of auxin(IAA),cytokinins(Z+ZR,iP+iPA,DHZ+DHZR),and gibberellic acid(GA3),while increasing levels of JA,abscisic acid(ABA),and brassinosteroids(BR).These hormonal shifts may underlie the enhanced defoliation observed with the combined treatment.Importantly,the TDZ-Me-JA combination did not adversely affect cotton yield,yield components,or fiber quality.Conclusion The combination of Me-JA and TDZ has a good defoliation effect without affecting crop yield or fiber quality.And it provides a promising foundation for the development of novel,environmentally friendly cotton defoliants.
基金funded by the Science Research and Technology Development from the Department of Science and Technology of Guangxi(14125008-2-17,1598006-5-7)the Natural Science Foundation of China(31360178)+1 种基金the Key Program of Guangxi Forestry Bureau([2015]7)as an independent project by the Key Laboratory of Gaungxi Fine Timber Forest Resources Cultivation(13A-01-01)
文摘A protocol for micropropagation using nodal explants from mature Pinus massoniana trees has been developed. Time of explant collection is crucial for the initial success of aseptic culture. Explants collected in early March gave the highest percentage of explant survival (64.5%) and shoot-forming percentage (52.3%). Thidiazuron (TDZ) concentration significantly influenced shoot formation; 4 mu M TDZ was optimum, with 4.8 shoots produced per explant with a mean length of 7.1 cm after 120 days of culture. Regenerated shoots rooted for 60 days in basic medium with 1 mu M NAA were ready for growth in pots. This is the first report on plantlet regeneration in vitro from mature trees of P. massoniana that provides a reliable method for propagating selected elites.
文摘Populus species are important resources for industry and in scientific study on biological and agricul- tural systems. Our objective was to enhance the frequency of plant regeneration in Himalayan poplar （Populus ciliata wall. ex Royle）. The effect of TDZ alone and in combi- nation with adenine and NAA was studied on the regen- eration potential of petiole explants. The explants were excised from Himalayan poplar plants grown in glass- houses. After surface sterilization the explants were cul- tured on shoot induction medium. High percentage shoot regeneration （86 %） was recorded on MS medium sup- plemented with 0.004 mg L-1 TDZ and 79.7 mg L-1 adenine. The regenerated shoots for elongation and multi- plication were transferred to MS ＋ 0.5 mg L-1 BAP ＋ 0.2 mg L-1 IAA ＋ 0.3 mg L-1 GA3. Root re- generation from shoots developed in vitro was observed on MS medium supplemented with 0.10 mg L-1 IBA. Hi- malayan poplar plantlets could be produced within 2 months after acclimatization in a sterile mixture of sand and soil. We developed a high efficiency plant regeneration protocol from petiole explants of P. ciliata.
基金Supported by Hebei Provincial Modern Agricultural Industry Technology System(HBCT2021230403)Project of Applied Technology Research and Development Center for Biological Breeding of Characteristic Horticultural Plants in Universities of Hebei Province.
文摘[Objectives]This study was conducted to investigate the application time,concentrations,and combinations of plant growth regulators,aiming to screen suitable concentrations,combinations,and treatment periods for enhancing the commercial quality of the fruit.[Methods]‘Xiangfei’grape was selected as the experimental material.Treatments were applied at two stages:full bloom and 10-14 d after flowering.Three plant growth regulators,gibberellin(GA 3),forchlorfenuron(CPPU),and thidiazuron(TDZ),were used at different concentrations and in various combinations.The aim was to investigate the effects of different treatments on the seedless rate and fruit quality of‘Xiangfei’grape and to identify the optimal protocol for seedlessness induction in this cultivar.[Results]The optimal treatment protocol was the application of GA 350 mg/L+TDZ 4 mg/L at full bloom,followed by clear water 10-14 d after full bloom.After this combined pre-and post-flowering treatment,a seedless rate of 73%was achieved.The corresponding fruit quality parameters were as follows:single berry weight,17.64 g;longitudinal diameter,28.94 mm;transverse diameter,30.21 mm;fruit firmness,8.41 N/cm_(2);and soluble protein content,0.94 mg/g.Compared with other treatments,this protocol improved berry longitudinal and transverse diameters,fruit firmness,single berry weight,soluble solid content,and soluble protein content in‘Xiangfei’berries.It also altered the fruit shape index,reduced tannin content,and had a minimal impact on vitamin C content.[Conclusions]This study can provide a theoretical basis and technical reference for the seedlessness production of‘Xiangfei’grape.
基金supported by the Innovation Team of Guangxi Mango Industry Project(No.nycytxgxcxtd-2021-06-02)Guangxi Key Laboratory of Biology for Mango(No.GKLBM02204)+2 种基金Science and Technology Major Projects of Guangxi(No.GXKJ-AA22068098-2)the Six One’Special Action of‘Strengthening Agriculture and Enriching People’by Science and Technology Vanguard(No.202304-04)the Youth Talent Fund Project of Guangxi Natural Science Foundation(Nos.2018GXNSFBA035558 and 2018GXNSFBA050026),China.
文摘Thidiazuron(TDZ)is used for the expansion of fruits,but excessive levels of TDZ lead to a decline in fruit quality.The appropriate concentration of TDZ for mango expansion without a decline in quality is not clear.In the present study,four different concentrations(5,10,15,and 20 mg/L)of TDZ were applied via spraying on mango plants,and several physiological and biochemical indicators were measured.The results showed that TDZ treatment significantly increased mango fruit size and single-fruit weight.In mango fruit,TDZ treatment decreased the disease index,delayed the increase in the malondialdehyde and H2O2 content,and maintained firmness and antioxidant capacities at a relatively high level during postharvest storage.At the same time,TDZ treatment delayed the decrease in the giberellin,indoleacetic acid and jasmonic acid content in mango,and reduced the accumulation of abscisic acid and ethylene.These trends are consistent with TDZ treatment leading to extension of the shelf life of mango.Furthermore,ethylene biosynthesis,signal transduction,and cell wall dismantling-related genes were investigated.The results indicated that the expression of the MiACS,MiETR2,MiERF113,MiERF010,MiERF054,MiEXP,MiPG14,MiPG21,MiCEL,and MiPEL genes in mango was inhibited under TDZ treatment compared with the control.In summary,TDZ treatment can significantly increase the size and weight of mango fruit and can extend its shelf life.The most suitable concentration is 10–15 mg/L TDZ,which will not affect the quality of mango fruit.
基金Supported by project of the Science and technology Ministry of China (Grant No.02 EFN216700794)
文摘The effectiveness of thidiazuron（TDZ）on adventitious bud and shoot formation from leaves of Robinia pseudoacacia was tested in combination with naphthaleneacetic acid （NAA）or 2,4-dichiorophenoxyacetic acid （2,4-D）,With the increasing of TDZ level,the induction rate of adventitious buds appeared an increasing trend and the highest rate was obtained by the combination of 2mg/L TDZ whth 0.1mg/L NAA.The excessive level of TDZ could induce useless cellae and easily produce hyperhydricity.Inhibition of shoot elongation by TDZ was overcome through transferring shoot cultures to a shoot proliferation medium lacking TDZ orcontaining NAA,benzyladenine （BA）and TDZ.Indole-3-butyric acid （IBA）was used to stimulate the rooting in vitro .Based on the number and length of rooting ,the treatment with 0.5mg/L IBA was the best.
