Commercial production of spinach(Spinacia oleracea L.)is centered in California and Arizona in the US,where downy mildew caused by Peronospora effusa is the most destructive disease.Nineteen typical races of P.effusa ...Commercial production of spinach(Spinacia oleracea L.)is centered in California and Arizona in the US,where downy mildew caused by Peronospora effusa is the most destructive disease.Nineteen typical races of P.effusa have been reported to infect spinach,with 16 identified after 1990.The regular appearance of new pathogen races breaks the resistance gene introgressed in spinach.We attempted to map and delineate the RPF2 locus at a finer resolution,identify linked single nucleotide polymorphism(SNP)markers,and report candidate downy mildew resistance(R)genes.Progeny populations segregating for RPF2 locus derived from resistant differential cultivar Lazio were infected using race 5 of P.effusa and were used to study for genetic transmission and mapping analysis in this study.Association analysis performed with low coverage whole genome resequencing-generated SNP markers mapped the RPF2 locus between 0.47 to 1.46 Mb of chromosome 3 with peak SNP(Chr3_1,221,009)showing a LOD value of 61.6 in the GLM model in TASSEL,which was within 1.08 Kb from Spo12821,a gene that encodes CC-NBS-LRR plant disease resistance protein.In addition,a combined analysis of progeny panels of Lazio and Whale segregating for RPF2 and RPF3 loci delineated the resistance section in chromosome 3 between 1.18–1.23 and 1.75–1.76 Mb.This study provides valuable information on the RPF2 resistance region in the spinach cultivar Lazio compared to RPF3 loci in the cultivar Whale.The RPF2 and RPF3 specific SNP markers,plus the resistant genes reported here,could add value to breeding efforts to develop downy mildew resistant cultivars in the future.展开更多
[Objectives]This study was conducted to promote the rational use of bioorganic fertilizers.[Methods]Stanley bioorganic fertilizer was selected to investigate the laws and characteristics of the effects of bioorganic f...[Objectives]This study was conducted to promote the rational use of bioorganic fertilizers.[Methods]Stanley bioorganic fertilizer was selected to investigate the laws and characteristics of the effects of bioorganic fertilizer on spinach growth with different application rates in a short term and found out the precise application rate.[Results]As the application rate of bioorganic fertilizer increasing,the emergence rate of spinach decreased.The total weights and leaf areas of spinach plants treated with different application rates of bioorganic fertilizers were all higher than those of the control check(CK).The total weights and leaf areas of spinach plants applied with bioorganic fertilizer at different rates were all higher than those of the CK.The total weight of spinach plants increased linearly with the application rate of bioorganic fertilizer increasing among treatments,while the leaf area fluctuated with the increase of bioorganic fertilizer concentration among various treatments.The average root volumes and average diameters of treatments applied with bioorganic fertilizer at different rates were all higher than those in the CK,but the average root length showed a different trend.The average root length was higher in the CK than in various bioorganic fertilizer treatments in the early growth period,but the differences of various treatments from the CK gradually decreased in the middle period,and in the later period,the root length of spinach treated with organic fertilizer gradually exceeded the CK.[Conclusions]This study provides a theoretical basis for the rational application of bioorganic fertilizers in spinach production.展开更多
The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are a...The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.展开更多
The effect and the mechanism of action of lanthanum, cerium and neodymium on aged seeds of spinach were studied. By LaCl_3, CeCl_3, and NdCl_3 treatment, the germination rate, germination index and vigor index of aged...The effect and the mechanism of action of lanthanum, cerium and neodymium on aged seeds of spinach were studied. By LaCl_3, CeCl_3, and NdCl_3 treatment, the germination rate, germination index and vigor index of aged spinach seeds are increased and the activities of superoxide dismutase, catalase and peroxidase are enhanced. Moreover the ·O_2^- and malondialdehyde content are decreased and the cell membrane permeability of aged spinach seeds is reduced. Among these three rare earth elements, Ce treatment enhances vigor of aged seeds most significantly, that of Nd treatment secondly and La treatment is not as effective as the other two treatments. The reason may be from 4f electron characteristic and alternation valence of REEs.展开更多
Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis ...Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3+ on energy transfer and oxygen evolution in photosystem Ⅱ (PS Ⅱ ) isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3+ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ (fluorescence quantum yield) and its oxygen evolving rate were enhanced by Ce^3+.展开更多
Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, ...Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order: Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.展开更多
The content and distribution characteristics of REE in spinach and soil under using REE and acid rain stress were studied by pot experiments. The results show that the content of REE is 0 527~0 696 (μg·g -...The content and distribution characteristics of REE in spinach and soil under using REE and acid rain stress were studied by pot experiments. The results show that the content of REE is 0 527~0 696 (μg·g -1 ) in the above ground portion of spinach, 2 668~3 003 (μg·g -1 ) in the under ground portion of spinach and 229 09~250 30 (μg·g -1 ) in the soil. With the acidity of acid rain increasing, the leaching of REE in plants and soil is strengthened and the amount of REE reduces with decreasing of pH value. After REE are used, though plants show the selective absorption to Ce group elements (especially spraying on leaves), regardless under acid rain stress or using REE or not, the distribution model of REE in the above ground and under ground portion of plants is basically the same with the control. Plants also follow the Oddo Harkins rule of the REE of distribution abundance, light rare earth elements is enriched, the minus of Eu is abnormal and admeasure of Ce is a rich model. The results show that REE in plants mainly come from soil and are affected by it.展开更多
The effect of Nd^(3+) on the photosynthesis and the growth of spinach was studied. The results show that Nd^(3+) improves the growth of spinach and increases chlorophyll content and photosynthetic rate. UV-Vis spectru...The effect of Nd^(3+) on the photosynthesis and the growth of spinach was studied. The results show that Nd^(3+) improves the growth of spinach and increases chlorophyll content and photosynthetic rate. UV-Vis spectrum indicates that the Soret band of chl-a in spinach with NdCl_3 treatment is blue shifted by 2 nm, and the Q band is red shifted by 1 nm, and the ratio of Soret band intensity and Q band intensity increases. FT-IR spectra show that the peak of porphyrin ring in chl-a of spinach with NdCl_3 treatment is widened, suggesting that the formation of Nd^(3+)-chl-a. Treated by NdCl_3, the fluorescence emission peak of PSⅡ in spinach leaves is blue shifted by 12 nm and the intensity declines obviously, indicating that Nd^(3+) is bound to the PSⅡ protein-pigment complex and the electron transfer rate increases.展开更多
To find a new way treating the wastewater from biogas reactors in a pig farm, vegetated floating bed was built for observing the water-purifying capability of water spinach (Ipomoea aquatic) planted on the water surfa...To find a new way treating the wastewater from biogas reactors in a pig farm, vegetated floating bed was built for observing the water-purifying capability of water spinach (Ipomoea aquatic) planted on the water surface. Experiments were carried out to record the growth and biomass accumulation of water spinach and its effect on purification of biogas wastewater. The results show that the water which mixed with biogas wastewater has been purified significantly by water spinach on the floating bed. During its growth season within four months, the overall length of water spinach reached 199 ± 35 cm, while its root length reached 63 ± 28.6 cm. The average weight of individual fresh plant is of 1285 ± 619.7 g. Meanwhile, the concentration of total nitrogen (TN) in water under the floating bed decreased from 8.9 ± 0.062 mg·L-1 to 0.5 ± 0.011 mg·L-1;the concentration of total phosphorus (TP) decreased from 4.4 ± 0.236 mg·L-1 to 0.92 ± 0.024 mg·L-1;the concentration of chemical oxygen demand (COD) decreased from 87.3 ± 6.68 mg·L-1 to 0.74 ± 0.46 mg·L-1. It suggests that the water spinach removed more than 90% of pollutants in terms of TN, TP, and COD from the water. Results show that the vegetated floating bed technique is a feasible way to dispose the biogas slurry.展开更多
Rising global CO<sub>2</sub> levels are a major factor that impacts not only the environment but also many plant functions including growth, productivity and nutritional quality. The study examined the imp...Rising global CO<sub>2</sub> levels are a major factor that impacts not only the environment but also many plant functions including growth, productivity and nutritional quality. The study examined the impact of elevated [CO<sub>2</sub>] on nutritional quality and growth characteristics of lettuce (Lactuca sativa) and spinach (Spinacia oleracea). Elevated [CO<sub>2</sub>] decreased the concentration of many important nutrients including nitrogen (protein), potassium and phosphorus in the edible parts of both lettuce and spinach. The nitrogen concentration in lettuce shoots was reduced by more than 30% at elevated [CO<sub>2</sub>] compared to the plants grown at ambient level of CO<sub>2</sub>. Similarly the concentration of a number of micronutrients including sulfur, zinc, copper and magnesium, was depressed in lettuce shoots. Although the total phenolic content and antioxidant capacity were higher in lettuce at elevated CO<sub>2</sub>, they were not affected in spinach. The photosynthetic activity was variable among the plant species while there was no increase in the carbon accumulation in these plants at elevated [CO<sub>2</sub>]. However, there was significant reduction in the leaf stomatal conductance in both lettuce and spinach in response to higher [CO<sub>2</sub>], which is likely affect both water loss from the leaves and their photosynthetic activity. The results indicate a broad adverse impact of rising [CO<sub>2</sub>] on the nutritional quality of commonly consumed leafy vegetables namely, lettuce and spinach.展开更多
基金This research was supported by a USDA-SCRI grant(2017-51181-26830)a USDA-AMS SCMP grant(16SCCMAR0001)the USDA NIFA Hatch project(ARK0VG2018 and ARK02440)to AS.
文摘Commercial production of spinach(Spinacia oleracea L.)is centered in California and Arizona in the US,where downy mildew caused by Peronospora effusa is the most destructive disease.Nineteen typical races of P.effusa have been reported to infect spinach,with 16 identified after 1990.The regular appearance of new pathogen races breaks the resistance gene introgressed in spinach.We attempted to map and delineate the RPF2 locus at a finer resolution,identify linked single nucleotide polymorphism(SNP)markers,and report candidate downy mildew resistance(R)genes.Progeny populations segregating for RPF2 locus derived from resistant differential cultivar Lazio were infected using race 5 of P.effusa and were used to study for genetic transmission and mapping analysis in this study.Association analysis performed with low coverage whole genome resequencing-generated SNP markers mapped the RPF2 locus between 0.47 to 1.46 Mb of chromosome 3 with peak SNP(Chr3_1,221,009)showing a LOD value of 61.6 in the GLM model in TASSEL,which was within 1.08 Kb from Spo12821,a gene that encodes CC-NBS-LRR plant disease resistance protein.In addition,a combined analysis of progeny panels of Lazio and Whale segregating for RPF2 and RPF3 loci delineated the resistance section in chromosome 3 between 1.18–1.23 and 1.75–1.76 Mb.This study provides valuable information on the RPF2 resistance region in the spinach cultivar Lazio compared to RPF3 loci in the cultivar Whale.The RPF2 and RPF3 specific SNP markers,plus the resistant genes reported here,could add value to breeding efforts to develop downy mildew resistant cultivars in the future.
基金Supported by Vegetable Innovation Team of Shandong Modern Agricultural Industry Technology System(SDAIT-05-18)。
文摘[Objectives]This study was conducted to promote the rational use of bioorganic fertilizers.[Methods]Stanley bioorganic fertilizer was selected to investigate the laws and characteristics of the effects of bioorganic fertilizer on spinach growth with different application rates in a short term and found out the precise application rate.[Results]As the application rate of bioorganic fertilizer increasing,the emergence rate of spinach decreased.The total weights and leaf areas of spinach plants treated with different application rates of bioorganic fertilizers were all higher than those of the control check(CK).The total weights and leaf areas of spinach plants applied with bioorganic fertilizer at different rates were all higher than those of the CK.The total weight of spinach plants increased linearly with the application rate of bioorganic fertilizer increasing among treatments,while the leaf area fluctuated with the increase of bioorganic fertilizer concentration among various treatments.The average root volumes and average diameters of treatments applied with bioorganic fertilizer at different rates were all higher than those in the CK,but the average root length showed a different trend.The average root length was higher in the CK than in various bioorganic fertilizer treatments in the early growth period,but the differences of various treatments from the CK gradually decreased in the middle period,and in the later period,the root length of spinach treated with organic fertilizer gradually exceeded the CK.[Conclusions]This study provides a theoretical basis for the rational application of bioorganic fertilizers in spinach production.
文摘The photosystem Ⅱ(PSⅡ) particles were purified by means of nano-anatase TiO_2 treatment of spinach and studied by spectroscopy. The results show that the electron transport and the oxygen-evolving rate of PSⅡ are accelerated after it has been treated with nano-anatase TiO_2; the UV-Vis absorption spectrum of PSⅡ particles is increased; the red shift of fluorescence emission peak of PSⅡ is 2 nm; the peak intensity is decreased; the PSⅡ signal Ⅱs of low temperature electron paramagnetic resonanace(EPR) spectrum is intensified under light, and the PSⅡ circular dichroism(CD) spectrum is similar to that of control. It is suggested that nano-anatase TiO_2 might bind to the PSⅡ reaction center complex and intensify the function of the PSⅡ electron donor, however, nano-anatase TiO_2 treatment does not change the configuration of the PSⅡ reaction center complex.
文摘The effect and the mechanism of action of lanthanum, cerium and neodymium on aged seeds of spinach were studied. By LaCl_3, CeCl_3, and NdCl_3 treatment, the germination rate, germination index and vigor index of aged spinach seeds are increased and the activities of superoxide dismutase, catalase and peroxidase are enhanced. Moreover the ·O_2^- and malondialdehyde content are decreased and the cell membrane permeability of aged spinach seeds is reduced. Among these three rare earth elements, Ce treatment enhances vigor of aged seeds most significantly, that of Nd treatment secondly and La treatment is not as effective as the other two treatments. The reason may be from 4f electron characteristic and alternation valence of REEs.
基金Project supported by the National Natural Science Foundation of China (20671067, 30470150)
文摘Due to 4f electron characteristics and alternation valence, cerium involved in an oxidation-reduction reaction in plant, closely relating to photosynthesis. Our studies proved that cerium could promote photosynthesis and greatly improve spinach growth. However, the mechanism of promoting energy transfer and conversion by cerium remains unclear. Here we reported that the effects of Ce^3+ on energy transfer and oxygen evolution in photosystem Ⅱ (PS Ⅱ ) isolated from spinach, which was related to 4f electron characteristics and alternation valence in Ce molecule. The methods of absorption spectrum, fluorescence spectrum were used in the research. Results showed that Ce^3+ treatment at low concentration could suitably change PS Ⅱ mieroenvironment, increase the absorbance of visible light, improve the energy transfer among amino acids within PS Ⅱ protein-pigment complex, and accelerate energy transport from tyrosine residue to chlorophyll a. In summary, the photochemical activity of PS Ⅱ (fluorescence quantum yield) and its oxygen evolving rate were enhanced by Ce^3+.
基金Project supported by the National Natural Science Foundation of China (20671067, 30470150)
文摘Chloroplasts were isolated from spinach treated with taCl3, CeCl3, and NdCl3. Because of owning 4f electron characteristics and alternation valence, Ce treatment presented the highest enhancement in light absorption, energy transfer from LHC Ⅱ to PS Ⅱ, excitation energy distribution from PS Ⅰ to PS Ⅱ, and fluorescence quantum yield around 680 nm. Compared with Ce treatment, Nd treatment resulted in relatively lower enhancement in these physiological indices, as Nd did not have alternation valence. La treatment presented the lowest enhancement, as La did not have either 4f electron or alternation valence. The increase in activities of whole chain electron transport, PS ⅡDCPIP photoreduction, and oxygen evolution of chloroplasts was of the following order: Ce〉Nd 〉La〉 control. However, the photoreduction activities of spinach PS I almost did not change with La, Ce, or Nd treatments. The results suggested that 4f electron characteristics and alternation valence of rare earths had a close relationship with photosynthesis improvement.
文摘The content and distribution characteristics of REE in spinach and soil under using REE and acid rain stress were studied by pot experiments. The results show that the content of REE is 0 527~0 696 (μg·g -1 ) in the above ground portion of spinach, 2 668~3 003 (μg·g -1 ) in the under ground portion of spinach and 229 09~250 30 (μg·g -1 ) in the soil. With the acidity of acid rain increasing, the leaching of REE in plants and soil is strengthened and the amount of REE reduces with decreasing of pH value. After REE are used, though plants show the selective absorption to Ce group elements (especially spraying on leaves), regardless under acid rain stress or using REE or not, the distribution model of REE in the above ground and under ground portion of plants is basically the same with the control. Plants also follow the Oddo Harkins rule of the REE of distribution abundance, light rare earth elements is enriched, the minus of Eu is abnormal and admeasure of Ce is a rich model. The results show that REE in plants mainly come from soil and are affected by it.
文摘The effect of Nd^(3+) on the photosynthesis and the growth of spinach was studied. The results show that Nd^(3+) improves the growth of spinach and increases chlorophyll content and photosynthetic rate. UV-Vis spectrum indicates that the Soret band of chl-a in spinach with NdCl_3 treatment is blue shifted by 2 nm, and the Q band is red shifted by 1 nm, and the ratio of Soret band intensity and Q band intensity increases. FT-IR spectra show that the peak of porphyrin ring in chl-a of spinach with NdCl_3 treatment is widened, suggesting that the formation of Nd^(3+)-chl-a. Treated by NdCl_3, the fluorescence emission peak of PSⅡ in spinach leaves is blue shifted by 12 nm and the intensity declines obviously, indicating that Nd^(3+) is bound to the PSⅡ protein-pigment complex and the electron transfer rate increases.
文摘To find a new way treating the wastewater from biogas reactors in a pig farm, vegetated floating bed was built for observing the water-purifying capability of water spinach (Ipomoea aquatic) planted on the water surface. Experiments were carried out to record the growth and biomass accumulation of water spinach and its effect on purification of biogas wastewater. The results show that the water which mixed with biogas wastewater has been purified significantly by water spinach on the floating bed. During its growth season within four months, the overall length of water spinach reached 199 ± 35 cm, while its root length reached 63 ± 28.6 cm. The average weight of individual fresh plant is of 1285 ± 619.7 g. Meanwhile, the concentration of total nitrogen (TN) in water under the floating bed decreased from 8.9 ± 0.062 mg·L-1 to 0.5 ± 0.011 mg·L-1;the concentration of total phosphorus (TP) decreased from 4.4 ± 0.236 mg·L-1 to 0.92 ± 0.024 mg·L-1;the concentration of chemical oxygen demand (COD) decreased from 87.3 ± 6.68 mg·L-1 to 0.74 ± 0.46 mg·L-1. It suggests that the water spinach removed more than 90% of pollutants in terms of TN, TP, and COD from the water. Results show that the vegetated floating bed technique is a feasible way to dispose the biogas slurry.
文摘Rising global CO<sub>2</sub> levels are a major factor that impacts not only the environment but also many plant functions including growth, productivity and nutritional quality. The study examined the impact of elevated [CO<sub>2</sub>] on nutritional quality and growth characteristics of lettuce (Lactuca sativa) and spinach (Spinacia oleracea). Elevated [CO<sub>2</sub>] decreased the concentration of many important nutrients including nitrogen (protein), potassium and phosphorus in the edible parts of both lettuce and spinach. The nitrogen concentration in lettuce shoots was reduced by more than 30% at elevated [CO<sub>2</sub>] compared to the plants grown at ambient level of CO<sub>2</sub>. Similarly the concentration of a number of micronutrients including sulfur, zinc, copper and magnesium, was depressed in lettuce shoots. Although the total phenolic content and antioxidant capacity were higher in lettuce at elevated CO<sub>2</sub>, they were not affected in spinach. The photosynthetic activity was variable among the plant species while there was no increase in the carbon accumulation in these plants at elevated [CO<sub>2</sub>]. However, there was significant reduction in the leaf stomatal conductance in both lettuce and spinach in response to higher [CO<sub>2</sub>], which is likely affect both water loss from the leaves and their photosynthetic activity. The results indicate a broad adverse impact of rising [CO<sub>2</sub>] on the nutritional quality of commonly consumed leafy vegetables namely, lettuce and spinach.