In rice, high-temperature stress(HT) during flowering results in decreased grain yield via a reduction in spikelet fertility;however, the effect of plant water status on spikelet fertility under HT remains unknown. To...In rice, high-temperature stress(HT) during flowering results in decreased grain yield via a reduction in spikelet fertility;however, the effect of plant water status on spikelet fertility under HT remains unknown. To investigate the relationship between spikelet water status and spikelet fertility under HT, two experiments were performed under temperature-controlled conditions using four genotypes with varying tolerance to HT. Rice plants were exposed to HT for seven consecutive days during the flowering stage under three soil water treatments(soil water potential 0, -20, and -40 kPa), as well as under hydroponic conditions in a separate experiment. HT significantly decreased spikelet fertility, pollen fertility, and anther dehiscence under each of the three water treatments. HT significantly increased the spikelet transpiration rate, and this change was accompanied by a significant decrease in the internal temperature of the spikelets. HT decreased pollen grain diameter in heat-sensitive genotypes. HT had varying effects on the water potential of panicles and anthers but increased anther soluble-sugar concentration. Different aquaporin genes showed different expression profiles under HT, and the expression levels of PIPs for plasma membrane intrinsic proteins and TIPs for tonoplast intrinsic proteins increased in anthers but decreased in glumes.Correlation analyses showed that anther dehiscence and pollen(spikelet) fertility were tightly associated with anther water status, and the expression levels of almost all anther aquaporin genes were significantly correlated with anther dehiscence under HT. In summary, an increased spikelet transpiration rate and decreased internal spikelet temperature were associated with alleviation of the effects of HT in rice genotypes with varying degrees of heat tolerance, and the response of spikelet water status to HT, involving increased total expression of aquaporins and soluble sugar content, thereby improved pollen fertility,anther dehiscence, and spikelet fertility, especially in heat-resistant genotypes. The heat-resistant genotypes N22 and SY63 may adopt different approaches to reduce heat damage.展开更多
The relation between seed viability and waterstatus in seed was studied. The experimentwas carried out at Zhongshan University.Seeds of hybrid rice Shanyou 63 were collectedfrom Guangdong Academy of Agriculture Sci-en...The relation between seed viability and waterstatus in seed was studied. The experimentwas carried out at Zhongshan University.Seeds of hybrid rice Shanyou 63 were collectedfrom Guangdong Academy of Agriculture Sci-ences in 1993 and then stored for one year inopen air or with silica gel. Before and afterstorage, the relative content of free water展开更多
In this paper,the artificial lake on the campus of Tibet University was taken as the research object.By detecting the water quality of the lake,the standard index method and comprehensive pollution index method were u...In this paper,the artificial lake on the campus of Tibet University was taken as the research object.By detecting the water quality of the lake,the standard index method and comprehensive pollution index method were used to understand the water quality characteristics,pollution status,and main pollutants of the Siyuan Lake.On this basis,the comprehensive nutritional status index method was used to evaluate the eutrophication status of the Siyuan Lake.The results showed that the overall water quality of the artificial lake was good,showing as still clean,with TN and TP being the main pollution factors of the artificial lake.The main nutritional indicators were TN,TP,and transparency,with a comprehensive nutritional level of middle eutropher.Based on the environmental characteristics of the artificial lake area on the campus of Tibet University,reasonable treatment measures have been proposed.It hoped to prevent and improve the water environment through these measures,and provide reference for the protection and restoration of campus landscape water body.展开更多
In this study,newly harvested and aged rice seeds were analyzed to determine their aging process,identify the difference between artificially and naturally aged seeds,and develop a rapid,accurate,and non-destructive d...In this study,newly harvested and aged rice seeds were analyzed to determine their aging process,identify the difference between artificially and naturally aged seeds,and develop a rapid,accurate,and non-destructive detection method for water status and water distribution of rice seed with different vigor.To this end,an artificially accelerated aging test was conducted on the newly harvested rice seeds.Then,low-field nuclear magnetic resonance(LF-NMR)technology was applied to test the new(Shennong No.9816,2018),old(Shennong No.9816,2017),and artificially aged seeds(Shennong No.9816,2018).A standard germination test was conducted for three types of seeds.Finally,the differences of water status and distribution between rice seeds of different vigor were analyzed based on the standard germination test results and wave spectrometry information collected using LF-NMR.The results indicated that new seeds,old seeds,and the artificially accelerated aging rice seeds all exhibited two water phases,and the vigor of rice seeds after the artificial accelerated aging test was lower than that of new seeds.There were significant differences between the frequencies of bound water at the time of the peak and the time at the end of the peak for the three types of seeds.The two times showed an increasing trend for rice seeds with poor vigor,indicating that the ability of the water in the rice seeds having poor vigor to combine with other substances was weakened.There were significant differences between the distributions of free water peak end time for the three types of seeds.All the rice seeds with poor vigor exhibited a decreasing trend at this time,indicating that the freedom of free water inside the rice seed samples with poor vigor was weakened.The total water content of the artificially aged seeds and the aged seeds was higher than that of the new seeds,but the free water content increased from artificially aged seeds to new seeds to aged seeds.This indicates that LF-NMR technology is an effective detection method that can simply compare the differences in seed vitality with respect to water distribution as well as differentiate the seed internal water content of artificially aged and naturally aged seeds.展开更多
Labisia pumila(Kacip fatimah)is a popular medicinal plant in Malaysia.The constituents of this plant have been reported to possess anticancer,antioxidant and anti-inflammatory properties.The growth and production of L...Labisia pumila(Kacip fatimah)is a popular medicinal plant in Malaysia.The constituents of this plant have been reported to possess anticancer,antioxidant and anti-inflammatory properties.The growth and production of L.pumila is greatly influenced by the plant water status.Current techniques to measure plant water status are generally based on the plant soil moisture,which apparently did not indicate the real water content inside the plant.There are other techniques to measure directly on the plant such as based on leaf water potential(LWP)and relative water content(RWC).However,these techniques are destructive and time consuming.In this study,four levels of evapotranspiration replacement(ER)treatment which were 100%ER,75%ER,50%ER and 25%ER was applied to 30 polybags of L.pumila plants.The plant water status was measured using an impedance spectroscopy technique.A pair of electrocardiogram(ECG)electrode connected to an impedance analyzer board was used to measure the impedance value of the leaf samples noninvasively.Plant water status parameters such as LWP,RWC,volumetric moisture content(VMC),and leaf thickness were measured using standard methods.The results show that after 20 weeks of treatment,25%ER had the highest impedance value ranged from 0.10 MX to 0.15 MX at the frequency of 70–100 kHz.The resistance of 100%ER at 20 weeks of treatment increased from 0.70 kX to 1.23 kX as the reactance decreased from 0.51 kX to 0.28 kX.Comparatively,the resistance of 25%ER increased from 1 kX to 1.10 kX as the reactance decreased from 0.88 kX to 0.83 kX.The polynomial regression of impedance measurements with plant water status parameters(VMC,leaf thickness,LWP and RWC)shows that LWP and RWC had the highest R2(0.78,0.73).The results show that impedance measurement technique is auspicious to evaluate plant water status.展开更多
Drought is one of the critical conditions for the growth and productivity of many crops including mung bean(Vigna radiata L.Wilczek).Screening of genotypes for variations is one of the suitable strategies for evaluati...Drought is one of the critical conditions for the growth and productivity of many crops including mung bean(Vigna radiata L.Wilczek).Screening of genotypes for variations is one of the suitable strategies for evaluating crop adaptability and global food security.In this context,the study investigated the physiological and biochemical responses of four drought tolerant(BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7),and four drought sensitive(BARI Mung-1,BARI Mung-3,BU Mung-4,BMX-05001)mung bean genotypes under wellwatered(WW)and water deficit(WD)conditions.The WW treatment maintained sufficient soil moisture(22%±0.5%,i.e.,30%deficit of available water)by regularly supplying water.Whereas,the WD treatment was maintained throughout the growing period,and water was applied when the wilting symptom appeared.The drought tolerant(DT)genotypes BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7 showed a high level of proline accumulation(2.52–5.99 mg g^(−1) FW),photosynthetic pigment(total chlorophyll 2.96–3.27 mg g^(−1) FW at flowering stage,and 1.62–2.38 mg g^(−1) FW at pod developing stage),plant water relation attributes including relative water content(RWC)(82%–84%),water retention capacity(WRC)(12–14)as well as lower water saturation deficit(WSD)(19%–23%),and water uptake capacity(WUC)(2.58–2.89)under WD condition,which provided consequently higher relative seed yield.These indicate that the tolerant genotypes gained better physiobiochemical attributes and adaptability in response to drought conditions.Furthermore,the genotype BMX-08010-2 showed superiority in terms of those physio-biochemical traits,susceptibility index(SSI)and stress tolerance index(STI)to other genotypes.Based on the physiological and biochemical responses,the BMX-08010-2 was found to be a suitable genotype for sustaining yield under drought stress,and subsequently,it could be recommended for crop improvement through hybridization programs.In addition,the identified traits can be used as markers to identify tolerant genotypes for drought-prone areas.展开更多
In order to develop the resources of native turfgrass,the morphological traits and drought resistance of native Siberian bluegrass(Poa sibirica,abbreviated as PS)was evaluated using the introduced Kentucky bluegrass&#...In order to develop the resources of native turfgrass,the morphological traits and drought resistance of native Siberian bluegrass(Poa sibirica,abbreviated as PS)was evaluated using the introduced Kentucky bluegrass'Midnight'(Poa pratensis,abbreviated as PP)as a control.Two water schemes were imposed to plants in this pot culture study in greenhouse.One was with drought stress persistent limiting water supply for 20 days,the other was re-hydrated until 14 days after drought.The leaf shape,turf color,water status and cell plasma membrane permeability were evaluated.Similar changing trends with these parameters were shown for both species,and there were not significant differences with most evaluations during drought and re-water periods.The values leaf width and length of PS were higher while leaf color intensity was slightly lower than that of PP,but the greenness of PS leaf was still visually acceptable.There were not significant differences with cell membrane stability between the two species.In comparison,the native wild species PS possessed the potential for to be domesticated into a new cultivar for turf industry.展开更多
To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C...To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C.Walker&A.Schüßler in pot cultivation.After 90 days of culture,saline–alkaline stress was induced with NaCl and NaHCO_(3)solution according to the main salt components in saline–alkaline soils.Based on the physiological response of P.anserina to the stress in the preliminary experiment,the solution concentrations of 0 mmol/L,75 mmol/L,150 mmol/L,225 mmol/L and 300 mmol/L were treated with stress for 10 days,respectively.The mycorrhizal colonization rate,mycorrhizal dependence,chlorophyll content,malondialdehyde content,antioxidant enzyme activities,osmoregulation substances content and water status were measured.The results showed that with the increase of NaCl and NaHCO_(3)stress concentration,mycorrhizal colonization rate,colonization intensity,arbuscular abundance and vesicle abundance decreased,and reached the lowest value at 300 mmol/L.Strong mycorrhizal dependence was observed after the symbiosis with AM fungus,and the dependence was higher under NaHCO_(3)treatment.Under NaCl and NaHCO_(3)stress,inoculation with AM fungus could increase chlorophyll content,decrease malondialdehyde content,increase activities of superoxide dismutase,peroxidase and catalase,increase contents of proline,soluble sugar and soluble protein,increase tissue relative water content and decrease water saturation deficit.It was concluded that salt–alkali stress inhibited the colonization of AM fungus,but the mycorrhiza still played a positive role in maintaining the normal growth of plants under salt–alkali stress.展开更多
Soil water and nutrient status are both of major importance for plant appearance and growth performance.The objective of this study was to understand the effect of biochar(1.5%)and a biochar-compost mixture(1.5%biocha...Soil water and nutrient status are both of major importance for plant appearance and growth performance.The objective of this study was to understand the effect of biochar(1.5%)and a biochar-compost mixture(1.5%biochar+1.5%compost)on the performance of Phragmites karka plants grown on a synthetic nutrient-poor sandy clay soil(50% sand,30% clay,and 20% gravel).Indicators of plant performance,such as growth,lignocellulosic biomass,water status(leaf water potential,osmotic potential,and turgor potential),mineral nutrition status,leaf gas exchange,and chlorophyll fluorescence,and soil respiration(carbon dioxide(CO2)flux)were assessed under greenhouse conditions.Biochar-treated plants had higher growth rates and lignocellulosic biomass production than control plants with no biochar and no compost.There was also a significant increase in soil respiration in the treatments with biochar,which stimulated microbial interactions.The increase in soil water-holding capacity after biochar amendment caused significant improvements in plant water status and plant ion(K^+,Mg^2+,and Ca^2+)contents,leading to an increase in net photosynthesis and a higher energy-use efficiency of photosystem II.Biochar-treated plants had lower oxidative stress,increased water-use efficiency,and decreased soil respiration,and the biochar-compost mixture resulted in even greater improvements in growth,leaf turgor potential,photosynthesis,nutrient content,and soil gas exchange.Our results suggest that biochar and compost promote plant growth with respect to nutrient uptake,water balance,and photosynthetic system efficiency.In summary,both the soil amendments studied could increase opportunities for P.karka to sequester CO2 and produce more fodder bio-active compounds and biomass for bio-energy on nutrient-poor degraded soils.展开更多
基金supported by the National Natural Science Foundation of China (31871541)。
文摘In rice, high-temperature stress(HT) during flowering results in decreased grain yield via a reduction in spikelet fertility;however, the effect of plant water status on spikelet fertility under HT remains unknown. To investigate the relationship between spikelet water status and spikelet fertility under HT, two experiments were performed under temperature-controlled conditions using four genotypes with varying tolerance to HT. Rice plants were exposed to HT for seven consecutive days during the flowering stage under three soil water treatments(soil water potential 0, -20, and -40 kPa), as well as under hydroponic conditions in a separate experiment. HT significantly decreased spikelet fertility, pollen fertility, and anther dehiscence under each of the three water treatments. HT significantly increased the spikelet transpiration rate, and this change was accompanied by a significant decrease in the internal temperature of the spikelets. HT decreased pollen grain diameter in heat-sensitive genotypes. HT had varying effects on the water potential of panicles and anthers but increased anther soluble-sugar concentration. Different aquaporin genes showed different expression profiles under HT, and the expression levels of PIPs for plasma membrane intrinsic proteins and TIPs for tonoplast intrinsic proteins increased in anthers but decreased in glumes.Correlation analyses showed that anther dehiscence and pollen(spikelet) fertility were tightly associated with anther water status, and the expression levels of almost all anther aquaporin genes were significantly correlated with anther dehiscence under HT. In summary, an increased spikelet transpiration rate and decreased internal spikelet temperature were associated with alleviation of the effects of HT in rice genotypes with varying degrees of heat tolerance, and the response of spikelet water status to HT, involving increased total expression of aquaporins and soluble sugar content, thereby improved pollen fertility,anther dehiscence, and spikelet fertility, especially in heat-resistant genotypes. The heat-resistant genotypes N22 and SY63 may adopt different approaches to reduce heat damage.
文摘The relation between seed viability and waterstatus in seed was studied. The experimentwas carried out at Zhongshan University.Seeds of hybrid rice Shanyou 63 were collectedfrom Guangdong Academy of Agriculture Sci-ences in 1993 and then stored for one year inopen air or with silica gel. Before and afterstorage, the relative content of free water
基金Supported by Innovative Projects for University Students(2022XCX020).
文摘In this paper,the artificial lake on the campus of Tibet University was taken as the research object.By detecting the water quality of the lake,the standard index method and comprehensive pollution index method were used to understand the water quality characteristics,pollution status,and main pollutants of the Siyuan Lake.On this basis,the comprehensive nutritional status index method was used to evaluate the eutrophication status of the Siyuan Lake.The results showed that the overall water quality of the artificial lake was good,showing as still clean,with TN and TP being the main pollution factors of the artificial lake.The main nutritional indicators were TN,TP,and transparency,with a comprehensive nutritional level of middle eutropher.Based on the environmental characteristics of the artificial lake area on the campus of Tibet University,reasonable treatment measures have been proposed.It hoped to prevent and improve the water environment through these measures,and provide reference for the protection and restoration of campus landscape water body.
基金This project was supported by National Natural Science Foundation of China(Grant No.31701318)National Natural Science Foundation of China Projects of International Cooperation and Exchanges(Grant No.31811540396)Basic Research Project of Education Department of Liaoning Province(Grant No.LSNJC201916).
文摘In this study,newly harvested and aged rice seeds were analyzed to determine their aging process,identify the difference between artificially and naturally aged seeds,and develop a rapid,accurate,and non-destructive detection method for water status and water distribution of rice seed with different vigor.To this end,an artificially accelerated aging test was conducted on the newly harvested rice seeds.Then,low-field nuclear magnetic resonance(LF-NMR)technology was applied to test the new(Shennong No.9816,2018),old(Shennong No.9816,2017),and artificially aged seeds(Shennong No.9816,2018).A standard germination test was conducted for three types of seeds.Finally,the differences of water status and distribution between rice seeds of different vigor were analyzed based on the standard germination test results and wave spectrometry information collected using LF-NMR.The results indicated that new seeds,old seeds,and the artificially accelerated aging rice seeds all exhibited two water phases,and the vigor of rice seeds after the artificial accelerated aging test was lower than that of new seeds.There were significant differences between the frequencies of bound water at the time of the peak and the time at the end of the peak for the three types of seeds.The two times showed an increasing trend for rice seeds with poor vigor,indicating that the ability of the water in the rice seeds having poor vigor to combine with other substances was weakened.There were significant differences between the distributions of free water peak end time for the three types of seeds.All the rice seeds with poor vigor exhibited a decreasing trend at this time,indicating that the freedom of free water inside the rice seed samples with poor vigor was weakened.The total water content of the artificially aged seeds and the aged seeds was higher than that of the new seeds,but the free water content increased from artificially aged seeds to new seeds to aged seeds.This indicates that LF-NMR technology is an effective detection method that can simply compare the differences in seed vitality with respect to water distribution as well as differentiate the seed internal water content of artificially aged and naturally aged seeds.
基金The authors gratefully acknowledge the financial support from the Ministry of Education Malaysia and Universiti Putra Malaysia with the UPM Research Grant Scheme(Project Code:GP-IPS/2013/9399814)The authors would also like to acknowledge Mrs.Nadirah Roslan who was involved in data collection process.
文摘Labisia pumila(Kacip fatimah)is a popular medicinal plant in Malaysia.The constituents of this plant have been reported to possess anticancer,antioxidant and anti-inflammatory properties.The growth and production of L.pumila is greatly influenced by the plant water status.Current techniques to measure plant water status are generally based on the plant soil moisture,which apparently did not indicate the real water content inside the plant.There are other techniques to measure directly on the plant such as based on leaf water potential(LWP)and relative water content(RWC).However,these techniques are destructive and time consuming.In this study,four levels of evapotranspiration replacement(ER)treatment which were 100%ER,75%ER,50%ER and 25%ER was applied to 30 polybags of L.pumila plants.The plant water status was measured using an impedance spectroscopy technique.A pair of electrocardiogram(ECG)electrode connected to an impedance analyzer board was used to measure the impedance value of the leaf samples noninvasively.Plant water status parameters such as LWP,RWC,volumetric moisture content(VMC),and leaf thickness were measured using standard methods.The results show that after 20 weeks of treatment,25%ER had the highest impedance value ranged from 0.10 MX to 0.15 MX at the frequency of 70–100 kHz.The resistance of 100%ER at 20 weeks of treatment increased from 0.70 kX to 1.23 kX as the reactance decreased from 0.51 kX to 0.28 kX.Comparatively,the resistance of 25%ER increased from 1 kX to 1.10 kX as the reactance decreased from 0.88 kX to 0.83 kX.The polynomial regression of impedance measurements with plant water status parameters(VMC,leaf thickness,LWP and RWC)shows that LWP and RWC had the highest R2(0.78,0.73).The results show that impedance measurement technique is auspicious to evaluate plant water status.
基金The authors extend their appreciation to the researchers Supporting Project No.(RSP-2021/298),King Saud University,Riyadh,Saudi Arabia.
文摘Drought is one of the critical conditions for the growth and productivity of many crops including mung bean(Vigna radiata L.Wilczek).Screening of genotypes for variations is one of the suitable strategies for evaluating crop adaptability and global food security.In this context,the study investigated the physiological and biochemical responses of four drought tolerant(BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7),and four drought sensitive(BARI Mung-1,BARI Mung-3,BU Mung-4,BMX-05001)mung bean genotypes under wellwatered(WW)and water deficit(WD)conditions.The WW treatment maintained sufficient soil moisture(22%±0.5%,i.e.,30%deficit of available water)by regularly supplying water.Whereas,the WD treatment was maintained throughout the growing period,and water was applied when the wilting symptom appeared.The drought tolerant(DT)genotypes BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7 showed a high level of proline accumulation(2.52–5.99 mg g^(−1) FW),photosynthetic pigment(total chlorophyll 2.96–3.27 mg g^(−1) FW at flowering stage,and 1.62–2.38 mg g^(−1) FW at pod developing stage),plant water relation attributes including relative water content(RWC)(82%–84%),water retention capacity(WRC)(12–14)as well as lower water saturation deficit(WSD)(19%–23%),and water uptake capacity(WUC)(2.58–2.89)under WD condition,which provided consequently higher relative seed yield.These indicate that the tolerant genotypes gained better physiobiochemical attributes and adaptability in response to drought conditions.Furthermore,the genotype BMX-08010-2 showed superiority in terms of those physio-biochemical traits,susceptibility index(SSI)and stress tolerance index(STI)to other genotypes.Based on the physiological and biochemical responses,the BMX-08010-2 was found to be a suitable genotype for sustaining yield under drought stress,and subsequently,it could be recommended for crop improvement through hybridization programs.In addition,the identified traits can be used as markers to identify tolerant genotypes for drought-prone areas.
基金Supported by the National Natural Science Fundation of China(31971772,31772354,31372091)College Student Innovation and Entrepreneurship Training Program of China(201910224035)。
文摘In order to develop the resources of native turfgrass,the morphological traits and drought resistance of native Siberian bluegrass(Poa sibirica,abbreviated as PS)was evaluated using the introduced Kentucky bluegrass'Midnight'(Poa pratensis,abbreviated as PP)as a control.Two water schemes were imposed to plants in this pot culture study in greenhouse.One was with drought stress persistent limiting water supply for 20 days,the other was re-hydrated until 14 days after drought.The leaf shape,turf color,water status and cell plasma membrane permeability were evaluated.Similar changing trends with these parameters were shown for both species,and there were not significant differences with most evaluations during drought and re-water periods.The values leaf width and length of PS were higher while leaf color intensity was slightly lower than that of PP,but the greenness of PS leaf was still visually acceptable.There were not significant differences with cell membrane stability between the two species.In comparison,the native wild species PS possessed the potential for to be domesticated into a new cultivar for turf industry.
基金This work was supported by the National Natural Science Foundation of China(31601986)Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH–Q16005).
文摘To investigate the effects of arbuscular mycorrhizal(AM)fungi on the growth and saline–alkaline tolerance of Potentilla anserina L.,the seedlings were inoculated with Claroideoglomus etunicatum(W.N.Becker&Gerd.)C.Walker&A.Schüßler in pot cultivation.After 90 days of culture,saline–alkaline stress was induced with NaCl and NaHCO_(3)solution according to the main salt components in saline–alkaline soils.Based on the physiological response of P.anserina to the stress in the preliminary experiment,the solution concentrations of 0 mmol/L,75 mmol/L,150 mmol/L,225 mmol/L and 300 mmol/L were treated with stress for 10 days,respectively.The mycorrhizal colonization rate,mycorrhizal dependence,chlorophyll content,malondialdehyde content,antioxidant enzyme activities,osmoregulation substances content and water status were measured.The results showed that with the increase of NaCl and NaHCO_(3)stress concentration,mycorrhizal colonization rate,colonization intensity,arbuscular abundance and vesicle abundance decreased,and reached the lowest value at 300 mmol/L.Strong mycorrhizal dependence was observed after the symbiosis with AM fungus,and the dependence was higher under NaHCO_(3)treatment.Under NaCl and NaHCO_(3)stress,inoculation with AM fungus could increase chlorophyll content,decrease malondialdehyde content,increase activities of superoxide dismutase,peroxidase and catalase,increase contents of proline,soluble sugar and soluble protein,increase tissue relative water content and decrease water saturation deficit.It was concluded that salt–alkali stress inhibited the colonization of AM fungus,but the mycorrhiza still played a positive role in maintaining the normal growth of plants under salt–alkali stress.
基金This study was conducted under the auspices of the Pakistan and German Collaborative Project(No.1-308/ILPU/HEC/2009)"Biochemical,Eco-Physiological,Anato-mical,and Morphological Stress Responses of Cash-Crop Halophytes"funded by the Higher Education Comission,Pakistan.Zainul Abideen would like to thank the Institute of Plant Ecology,Justus-Liebig University and the Institute of Botany,Gottfried Wilhelm Leibniz University of Germany for the use of their facilities.
文摘Soil water and nutrient status are both of major importance for plant appearance and growth performance.The objective of this study was to understand the effect of biochar(1.5%)and a biochar-compost mixture(1.5%biochar+1.5%compost)on the performance of Phragmites karka plants grown on a synthetic nutrient-poor sandy clay soil(50% sand,30% clay,and 20% gravel).Indicators of plant performance,such as growth,lignocellulosic biomass,water status(leaf water potential,osmotic potential,and turgor potential),mineral nutrition status,leaf gas exchange,and chlorophyll fluorescence,and soil respiration(carbon dioxide(CO2)flux)were assessed under greenhouse conditions.Biochar-treated plants had higher growth rates and lignocellulosic biomass production than control plants with no biochar and no compost.There was also a significant increase in soil respiration in the treatments with biochar,which stimulated microbial interactions.The increase in soil water-holding capacity after biochar amendment caused significant improvements in plant water status and plant ion(K^+,Mg^2+,and Ca^2+)contents,leading to an increase in net photosynthesis and a higher energy-use efficiency of photosystem II.Biochar-treated plants had lower oxidative stress,increased water-use efficiency,and decreased soil respiration,and the biochar-compost mixture resulted in even greater improvements in growth,leaf turgor potential,photosynthesis,nutrient content,and soil gas exchange.Our results suggest that biochar and compost promote plant growth with respect to nutrient uptake,water balance,and photosynthetic system efficiency.In summary,both the soil amendments studied could increase opportunities for P.karka to sequester CO2 and produce more fodder bio-active compounds and biomass for bio-energy on nutrient-poor degraded soils.
