[Objectives]This study was conducted to investigate the toxicity of heavy metal antimony(Sb) to ramie(Boehmeria nivea(L.) Gaudich.) and the tolerance response in ramie. [Methods] A pot experiment was conducted to stud...[Objectives]This study was conducted to investigate the toxicity of heavy metal antimony(Sb) to ramie(Boehmeria nivea(L.) Gaudich.) and the tolerance response in ramie. [Methods] A pot experiment was conducted to study the effects of Sb stress on root growth and Sb accumulation and transport of the root system of cultivated ramie Zhongzhu No.1, as well as on the physiological characteristics of ramie leaves. [Results] The plant height and root dry weight and volume of Zhongzhu No.1 showed an effect of "promoting at low concentrations and inhibiting at high concentrations" with the increase of Sb concentration, and decreased significantly at the concentration of 4 000 mg/kg, but no obvious toxic growth symptoms were observed. The content of Sb in roots(289.7-508.6 mg/kg) and the root-shoot transfer factor(0.09-0.57) of Zhongzhu No.1 increased with the increase of soil Sb concentration, but the change of Sb bioconcentration factor in roots was opposite, indicating that high concentrations of Sb in soil could promote the absorption of Sb in roots and the transport of Sb to the aboveground part, but the Sb enrichment capacity of roots was relatively reduced with the increase of soil Sb. Sb stress had a certain impact on the physiological characteristics of ramie leaves. With the increase of Sb treatment concentration, MDA, POD and SOD showed a change trend of "first increasing and then decreasing", while CAT gradually increased, indicating that Sb stress caused changes in the physiological characteristics of ramie leaves, thereby affecting plant growth and development. [Conclusions] This study provides a theoretical basis for ecological restoration of ramie in mining areas.展开更多
Numerous growth and physiological variables of 3-week-old Populus simonii × P.nigra seedlings were assessed after treatment with either nitrate nitrogen(NO_(3)^(−)--N)(0.1,0.5,1,5,or 10 mmol·L^(−1)) or ammon...Numerous growth and physiological variables of 3-week-old Populus simonii × P.nigra seedlings were assessed after treatment with either nitrate nitrogen(NO_(3)^(−)--N)(0.1,0.5,1,5,or 10 mmol·L^(−1)) or ammonium nitrogen(NH_(4)^(+)+-N)(0.1,0.5,1,5,or 10 mmol·L^(−1)) to determine the best nitrogen form and concentration to optimize growth,biomass allocation,pigment content,and photosynthetic capacity.The results of combining membership function and an evaluation index suggested that,5 mmol·L^(−1) nitrogen,regardless of the form,yielded the highest comprehensive evaluation index and good growth.In addition,a Pearson correlation analysis and network visualization revealed that the total mass,shoot mass,root mass,leaf dry mass,plant height,leaf area,chlorophyll a and total chlorophyll had a physiological index connectivity degree≥15 for both nitrogen forms.Net photosynthetic rate,stomatal conductance,transpiration rate,maximum photochemical efficiency of PSII,total nitrogen content,ground diameter,chlorophyll b,and carotenoid were unique indices for evaluating NH_(4)^(+)+-N-based nutrition,which could provide a theoretical basis for evaluating the effects of nitrogen fertilizer on seedlings,cultivation periods,and stress tolerance in P.simonii× P.nigra.展开更多
The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of wate...The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of water was investigated. It established the reduction of seed germination both under direct and indirect effects due to water action of attenuated geomagnetic field. A negative effect of hypomagnetic field on grown characteristics of seeds under indirect effect via water was decreased by the low doses of γ-irradiation, and was increased by low doses of α-irradiation, i.e. ionized radiation was the dominant factor in their combined action. It was revealed the increasing of the value of the oxidation-reduction potential of water under the influence of low-intensive α-ir-radiation (239Pu), γ-irradiation (137Cs) and also that the magnetic induction attenuated pointing to a natural decline. The increasing of the oxidation-reduction potential value testifies about “the regular decreasing of internal energy of water molecules” and the increasing of its oxidative properties, which, in our opinion, is caused the inhibition of the germination of seeds. It is supposed that namely water is the main component in the effects of studying factors on bio-objects, which acts due to the alterations of the properties and structural content of water.展开更多
Nitrogen plays a very important role in peanut nutrition and fertilization.For peanuts,the nitrogen nutrition comes from root nodules,soil and fertilizer,which are separately referred to as root nodule nitrogen,soil n...Nitrogen plays a very important role in peanut nutrition and fertilization.For peanuts,the nitrogen nutrition comes from root nodules,soil and fertilizer,which are separately referred to as root nodule nitrogen,soil nitrogen and fertilizer nitrogen.The research obtained following findings.(ⅰ)The nitrogen supply ratio of the three nitrogen sources for peanut is about 5∶3∶2.There are significant differences in the nitrogen supply capacity of the three nitrogen sources.The root nodules have the largest variation in nitrogen fixation and have a high potential for development.Nitrogen fixation in root nodules is closely related to carbon metabolism indicators such as photosynthesis in peanut leaves.Phosphorus application could increase the accumulation of three nitrogen sources,and the increase in nodule nitrogen accumulation is greater than that of soil nitrogen and fertilizer nitrogen.(ⅱ)Nitrogen fertilizer has a significant effect on nitrogen nutrition of peanuts.Different forms of nitrogen fertilizers,such as amide nitrogen,ammonium nitrogen,nitrate nitrogen and mixed ammonium nitrate nitrogen,have significant effects on nitrogen metabolism and nitrogen accumulation in peanuts.Amide nitrogen fertilizer is beneficial to improving the activity of enzymes related to nitrogen metabolism and nitrogen accumulation.Controlled-release fertilizer can significantly increase the content of soluble protein and improve the activities of NRase,GDH,GS,GPT,etc.in roots and leaves at the pod setting and mature stages of peanuts,which is favorable for delaying the plant senescence and increasing the yield of peanuts.Mixed application of common nitrogen fertilizer and slow-release fertilizer can increase the soil nitrate nitrogen level at the later growth stage,which is beneficial to the development of the root system at the later stage of growth,increasing the distribution ratio of nitrogen in the pods,and also favorable for increasing the yield and nitrogen utilization rate.(ⅲ)Increasing the ploughing depth,improving fertilization methods,selecting nitrogen-efficient varieties,paying attention to foliar topdressing,and adopting fertilizer-water integrated cultivation are conducive to increasing the nitrogen utilization rate of peanuts,reducing the amount of nitrogen fertilizers,accordingly saving costs,increasing efficiency and realizing sustainable development of agricultural production.展开更多
Experiments were conducted to evaluate the physiological and the biochemical characteristics of waxy wheat seeds under accelerated aging conditions. Five waxy wheat lines, which were Waxy 1, Waxy 4, Waxy 8, Waxy 9, an...Experiments were conducted to evaluate the physiological and the biochemical characteristics of waxy wheat seeds under accelerated aging conditions. Five waxy wheat lines, which were Waxy 1, Waxy 4, Waxy 8, Waxy 9, and Waxy 15; and five non-waxy wheat lines: S-39, 04J89, Jan-81, Ⅲ42-4, and Ⅲ10 were studied. The seeds were subjected to accelerated aging at 40℃, 45℃, 50℃, 55℃, and 60℃, and 90% relative humidity for 0, 2, 4, 6, and 8 days, respectively. The results showed a gradual increase in conductivity and decrease in germination rate during accelerated aging. SOD, POD and CAT activities increased at low-grade treatment, but decreased at severe treatment. On the other hand, the soluble protein content decreased at 45℃, but successively increased, then decreased 50℃. From the above study, it showed that 90% RH at 55℃ was the best accelerated aging condition for optimum efficiency in a shorter period.展开更多
[Objectives]This study was conducted to explore the mechanism of soybean cytoplasmic-nuclear male sterility.[Methods]With soybean cytoplasmic-nuclear male sterile line JLCMS9 A and its homotype maintainer line JLCMS9 ...[Objectives]This study was conducted to explore the mechanism of soybean cytoplasmic-nuclear male sterility.[Methods]With soybean cytoplasmic-nuclear male sterile line JLCMS9 A and its homotype maintainer line JLCMS9 B as experimental materials,the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),malondialdehyde(MDA)content,starch content,soluble protein content,soluble sugar content and free proline content in flower buds,alabastrums and mature flowers were determined,and the contents and changes of auxin(IAA),gibberellin(GA3),isopentenyl adenosine(iPA)and abscisic acid(ABA)at the three stages were analyzed.[Results]The activity of SOD and CAT and the contents of MDA and free proline in the sterile line at the flower bud stage were lower than those of the maintainer line,but the opposite was true at the alabastrum stage and the flowering stage,and their values were higher than those of the maintainer line;the POD activity of the sterile line was significantly lower than that of the maintainer line at the flower bud stage,and the opposite was true at the alabastrum stage and the flowering stage,and its values were higher than those of the maintainer line;and the starch content and soluble sugar content of sterile line 9 A showed an overall upward trend,and were significantly lower than those of the maintainer line 9 B at the alabastrum stage and the flowering stage.During the whole development process of floral organs,the content of IAA in sterile line 9 A showed a trend of first increasing and then decreasing,and the content of iPA increased gradually.The contents of hormones in the sterile line were lower than those in the maintainer line.The ratios of IAA/ABA,IAA/GA3,IAA/iPA and ABA/GA3 in the sterile line were significantly different from those in the maintainer line.It is inferred that the abnormal physiological characteristics of floral organ development are related to the cytoplasmic-nuclear male sterility of soybean.The alabastrum stage may be a critical period for the occurrence of abnormal physiological and biochemical indexes in the floral organs of soybean cytoplasmic-nuclear male sterile lines.[Conclusions]This study provides a theoretical basis for the breeding of fine sterile lines of soybean and the research on the mechanism of sterility.展开更多
In order to study the effects of seed soaking with Paclobutrazol( PP333) on the tillering and physiological characteristics of sugarcane seedlings,sugar cane variety ROC22 was used as experimental material. The effect...In order to study the effects of seed soaking with Paclobutrazol( PP333) on the tillering and physiological characteristics of sugarcane seedlings,sugar cane variety ROC22 was used as experimental material. The effects of seed soaking with different concentrations of PP333 were studied. The tiller number and growth of sugarcane were surveyed at the 6-leaf stage,the physiological indicators such as chlorophyll content,soluble protein content,proline content and peroxidase activity were measured at the 2-leaf,4-leaf,and 6-leaf stages. The results showed that the seed soaking with PP333 can effectively improve the tillering of sugarcane seedlings. The suitable concentration for the tillering of sugarcane and the growth and development of sugarcane was of 50 mg/L; the seed soaking with PP333 significantly increased the chlorophyll,soluble protein,proline,and peroxidase activity of leaves of sugarcane seedlings; the content of chlorophyll and soluble protein in leaves of sugarcane seedlings treated with 90 mg/L PP333 was the highest,and the proline content and peroxidase activity of sugarcane treated with 50 mg/L PP333 were the highest.展开更多
Canopy temperature strongly influences crop yield formation and is closely related to plant physiological traits.However, the effects of nitrogen treatment on canopy temperature and rice growth have yet to be comprehe...Canopy temperature strongly influences crop yield formation and is closely related to plant physiological traits.However, the effects of nitrogen treatment on canopy temperature and rice growth have yet to be comprehensively examined. We conducted a two-year field experiment with three rice varieties(HD-5, NJ-9108, and YJ-805) and three nitrogen treatments(zero-N control(CK), 200 kg ha~(–1)(MN), and 300 kg ha~(–1)(HN)). We measured canopy temperature using a drone equipped with a high-precision camera at the six stages of the growth period. Generally,canopy temperature was significantly higher for CK than for MN and HN during the tillering, jointing, booting, and heading stages. The temperature was not significantly different among the nitrogen treatments between the milky and waxy stages. The canopy temperature of different rice varieties was found to follow the order: HD-5>NJ-9108>YJ-805, but the difference was not significant. The canopy temperature of rice was mainly related to plant traits, such as shoot fresh weight(correlation coefficient r=–0.895), plant water content(–0.912), net photosynthesis(–0.84), stomatal conductance(–0.91), transpiration rate(–0.90), and leaf stomatal area(–0.83). A structural equation model(SEM) showed that nitrogen fertilizer was an important factor affecting the rice canopy temperature.Our study revealed:(1) A suite of plant traits was associated with the nitrogen effects on canopy temperature,(2) the heading stage was the best time to observe rice canopy temperature, and(3) at that stage, canopy temperature was negatively correlated with rice yield, panicle number, and grain number per panicle. This study suggests that canopy temperature can be a convenient and accurate indicator of rice growth and yield prediction.展开更多
Leaf traits can directly reflect the adaptation strategies of plants to the environment.However,there is limited knowledge on the adaptation strategies of heteromorphic leaves of male and female Populus euphratica Oli...Leaf traits can directly reflect the adaptation strategies of plants to the environment.However,there is limited knowledge on the adaptation strategies of heteromorphic leaves of male and female Populus euphratica Oliv.in response to individual developmental stages(i.e.,diameter class)and canopy height changes.In this study,morphological and physiological properties of heteromorphic leaves of male and female P.euphratica were investigated.Results showed that both male and female P.euphratica exhibited increased leaf area(LA),leaf dry weight(LDW),leaf thickness(LT),net photosynthetic rate(P_(n)),transpiration rate(T_(r)),stomatal conductance(g_(s)),proline(Pro),and malondialdehyde(MDA)concentration,decreased leaf shape index(LI)and specific leaf area(SLA)with increasing diameter and canopy height.Leaf water potential(LWP)increased with increasing diameter,LWP decreased significantly with increasing canopy height in both sexes,and carbon isotope fraction(δ^(13)C)increased significantly with canopy height in both sexes,all of which showed obvious resistance characteristics.However,males showed greater LA,LT,P_(n),T_(r),and Pro than females at the same canopy height,and males showed significantly higher LA,SLA,LT,P_(n),T_(r),g_(s),and MDA,but lower LWP and δ_(1)3C than females at the same canopy height,suggesting that male P.euphratica have stronger photosynthetic and osmoregulatory abilities,and are sensitive to water deficiency.Moreover,difference between male and female P.euphratica is closely related to the increase in individual diameter class and canopy height.In summary,male plants showed higher stress tolerance than female plants,and differences in P_(n),g_(s),T_(r),Pro,MDA,δ_(13)C,and LWP between females and males were related to changes in leaf morphology,diameter class,and canopy height.The results of this study provide a theory for the differences in growth adaptation strategies during individual development of P.euphratica.展开更多
This study aimed to explore the cold tolerance of two cultivars of Dendrobium officinale(MG1,MG2)grown in different regions of China.Under-2℃ incubation,cultivar MG1 remained active after 3 d,and continued to grow af...This study aimed to explore the cold tolerance of two cultivars of Dendrobium officinale(MG1,MG2)grown in different regions of China.Under-2℃ incubation,cultivar MG1 remained active after 3 d,and continued to grow after returning to room temperature.However,MG2 could only maintain its activity after 2 d treatment at−2℃,and the seedlings died with the low temperature treatment time.Investigation of the characteristics of the plants grown in the south(Hangzhou)or north(Zhengzhou)of China indicated that the leaves of MG1 also had reduced stomatal density,the highest thickness,and a compact microstructure.The contents of proline and soluble sugars were higher in MG1 than those in MG2.The cultivar MG1 had higher SOD enzyme activity than MG2,while CAT and POD activities in samples from Zhengzhou were higher than those from Hangzhou.The contents of polysaccharides and alkaloids in stems of in MG1 were higher than those in MG2,while the content of flavonoids in the Zhengzhou samples was higher than that in the Hangzhou samples.In addition,plant heights,stem diameters,and chlorophyll content were higher in MG1.Overall,MG1 had better cold resistance than MG2.MG1 is a cold tolerant cultivar with thick leaves and reduced stomatal density,higher contents of soluble sugars,proline,CAT,POD,polysaccharides,flavonoids and alkaloids,which together make it more adaptable to low temperatures.Thus,the cultivar MG1,with its demonstrated cold tolerance,can accordingly be grown on a large scale in cold regions,thereby expanding the available planting area for this important traditional medicinal plant to meet the increasing commercial demand for it.展开更多
[Objectives]This study was conducted to investigate the photosynthetic physiological characteristics of Populus euphratica trees at different forest ages in the desert area of Minqin in response to drought stress.[Met...[Objectives]This study was conducted to investigate the photosynthetic physiological characteristics of Populus euphratica trees at different forest ages in the desert area of Minqin in response to drought stress.[Methods]With P.euphratica trees of different ages in Minqin as the research object,the water characteristics and photosynthetic physiological indexes(chlorophyll,soluble sugar,POD,SOD and MDA)were compared under different conditions.[Results]On the time gradient,the soil water contents of P.euphratica of different ages decreased continuously with the extension of irrigation stop time,but the decreases were small.Under the same stress treatment,the soil water contents of P.euphratica of different ages increased with the deepening of soil layer,but the differences were not significant(P>0.05).Under normal condition,the chlorophyll contents of P.euphratica at three ages gradually increased with the increase of age.The chlorophyll contents in leaves of P.euphratica at different ages were all lower under normal condition and higher under water stress.The changes of POD and SOD activity in leaves of P.euphratica at different ages under different conditions were basically the same,showing that the enzyme activity was higher under water stress than under normal under.The MDA contents in leaves of the young and middle P.euphratica forests were higher under water stress at 7 and 21 d than under normal condition,and the differences were not significant(P>0.05);and the MDA content in leaves of the mature P.euphratica forest was higher under water stress at 21 and 35 d than under normal condition.Drought stress has a certain effect on the photosynthetic physiological characteristics of P.euphratica.In summary,under drought stress,the chlorophyll content,SOD and POD activity,and MDA molar concentration in the leaves of P.euphratica were basically higher than under normal condition,indicating that P.euphratica could resist drought environment through osmotic adjustment and showed strong drought resistance.[Conclusions]This study provides a theoretical reference for the restoration,protection and reconstruction of natural P.euphratica forests in the desert area of Minqin.展开更多
The physiological properties of new compact vertical-leaf type varieties,such as corn Zhengdan 958,Xundan 18,Jidan 7,etc.were analyzed in order to provid references for its large extension and new high-yield breeding....The physiological properties of new compact vertical-leaf type varieties,such as corn Zhengdan 958,Xundan 18,Jidan 7,etc.were analyzed in order to provid references for its large extension and new high-yield breeding.Results showed that reasons of high-yield included reasonable indices of leaf-area changing,long keeping of corn leaves and slow aging.Photosynthetic pigment,protein and soluble sugar in varietal leaves were high with the high peroxide enzyme activation,photosynthesis inherent ability and photosynthesis eff iciency,but with low malondialdehyde.The volume of grain seed was big,with long forming or starch grouting time of cells and the weight of thousand-granules was high.It indicated that Zhengdan 958 was still the best corn variety for the extensive utilization.The seeds production should pay attention to keep the pure degree and the hallmark for giving full potential advantages on the yield of these species.展开更多
To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the ...To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the physiological and yield characteristics of late rice in China,and determine the appropriate machine transplanting method for late rice,which was expected to provide a basis for high-yield and high-efficient cultivation of machine-transplanted late rice.Hybrid indica rice Taiyou 398 and conventional indica rice Jing Gangruanzhan were selected as the research objects,and large-pot carpet seedling machine transplanting(M1),conventional pot carpet seedling machine transplanting(M2)and ordinary carpet seedling machine transplanting(M3)were adopted respectively to analyze their effects on seedling quality,population physiological characteristics,yield and its components and economic benefits of late rice.The results showed that compared with M2 and M3,M1 achieved higher seedling quality,showing significant advantages in the early stage despite average root entwining force that met the requirement of machine transplanting.The seedlings transplanted using M1 had shorter recovery period after mechanical transplanting,with earlier tillering,earlier peak seedling,and slower declining of stems and tillers in the late stage;the peak seedling number was not high,but the effective tiller number and earbearing tiller percentage were significantly higher than those achieved by the other two machine transplanting methods.Also,M1 achieved stronger photosynthetic capacity of flag leaves before HS,with more photosynthetic products in stems and leaves transported to panicles and more efficiently after HS.Compared with seedlings transplanted using M2 and M3,the recovery period of those transplanted using M1 was shortened by 3 and 5 d,the heading stage(HS),and maturity stage(MS)were advanced,which effectively reduced the risk and impact of“cold dew wind”on machine-transplanted late rice.M1 had significant yield increase advantage and economic benefit,with better grain maturity,and“larger panicles,more panicles,more and fuller grains”.M1 achieved an average yield increase of 10.31%-11.10%,20.67%-25.10%in 2 years,and an average income increase of 18.65%-131.06%and 62.85%-323.78%,respectively.Therefore,vigorously developing M1 is the key to the high-yield and high-efficient cultivation of machine-transplanted late rice in China.展开更多
AM1(ABA-mimicking ligand)is a newly identified signaling molecule for plants during drought tolerance.To investigate the potential role of AM1 in response of rapeseed to drought stress,we conducted experiments by grow...AM1(ABA-mimicking ligand)is a newly identified signaling molecule for plants during drought tolerance.To investigate the potential role of AM1 in response of rapeseed to drought stress,we conducted experiments by growing rapeseed plants under different levels of drought stress with or without applying AM1 or ABA in a rain shelter.The results indicated that drought significantly inhibited rapeseed growth by damaging the photosyn-thesis system,increasing active oxygen accumulation,destroying the oxidative system,and worsening membrane lipid peroxidation.Exogenously applied AM1 and ABA both relieved the damage to rapeseed that was induced by drought stress.Compared with the drought-treated rapeseed,the AM1 treatment significantly improved plant height,number of greelp leaves,root collar thickness,leaf area,dry matter weight,and root cap ratios of rapeseed.In addition,Pn,Gs,Ci,Tr were significantly increased by the AM1 treatment.The AM1 treatment also alleviated the drought induced reductions in Fv/Fm,ΦPSII,qN and ETR;induced an increase in NPQ;and resulted in decreased active oxygen accumulation and membrane lipid peroxidation.Although the ABA treatment relieved photosynthetic fluorescence and antioxidation system parameters to some extent,the effect was inferior to AM1 treatment.Yield under AM1 treatment was higher than that under ABA treatment but was still far lower than that of normal water supply control.In summary,AM1 is functionally similar to ABA in terms of drought relief and regulation,moreover has a better effect.展开更多
Quinolinate phosphoribosyltransferase(QPRTase),a key enzyme in ensuring nicotinic acid is available for the synthesis of defensive pyridine alkaloids in Nicotiana species,also plays an important role in nicotinamide a...Quinolinate phosphoribosyltransferase(QPRTase),a key enzyme in ensuring nicotinic acid is available for the synthesis of defensive pyridine alkaloids in Nicotiana species,also plays an important role in nicotinamide adenine dinucleotide(NAD)biosynthesis.In this study,the morphological traits,the quality characteristics and photosynthetic parameters in QPT-overexpressing/interfering tobacco plants were investigated,respectively.Results showed that the interference of QPT gene not only reduced significantly the morphological traits including plant height,stem girth,leaf number and leaf length,etc.at 20 days after transplanting(DAT),but the flowering period was delayed 10-15 d in interfered tobaccos compared with the overexpressed,control and wild-type counterparts.However,at 40 DAT and 60 DAT,only three indexes(plant height,stem girth and leaf number)in QPT-interfering plants appeared significant difference in comparison with other three types of tobacco lines.Meanwhile,the determination results from nicotine,sugar,K+and Cl-content showed the nicotine content in interfered plants was always significantly lower than that in overexpressed plants,control and the wild-type ones respectively whatever toppling or not.At the same time,the toppling treatment also caused the increasement of K+content among the four different tobacco lines,but the maximum increase amplitude of K+content was found in QPT-overexpressing tobaccos while the minimum appeared in QPT-interfering plants.Finally,QPT-interference in transgenic tobaccos likewise affected the photosynthesis by reducing net photosynthetic rate(Pn),stomata conductance(Gs)and transpiration rate(Tr),while there was no significant difference between QPT-overexpressing plants and the controls and the wild-types.展开更多
Transplantation experiment was carried out using biennial container seedlings and bare root seedlings of Phoebe zhennan S. Lee as materials. In the experiment,it measured the growth indicators such as the seedling hei...Transplantation experiment was carried out using biennial container seedlings and bare root seedlings of Phoebe zhennan S. Lee as materials. In the experiment,it measured the growth indicators such as the seedling height,basal diameter,and number of branches and leaves. Besides,it also measured net photosynthetic rate( Pn),transpiration rate( Tr),stomatal conductance( Gs),intercellular CO_2 concentration( Ci) and soluble sugar,soluble protein,malondialdehyde( MDA) content,superoxide dismutase activity and root activity. The results indicated that the growth indicators of the Phoebe container seedlings performed the best in the plant height,basal diameter,and number of branches and leaves; photosynthetic capacity was the strongest,and the fertilization could enhance the photosynthetic capacity of seedlings; soluble sugar,soluble protein content,superoxide dismutase activity and root activity of Phoebe container seedlings were higher than that of bare root seedlings.展开更多
Improving turfgrass drought resistance and save-water features are very important to solve water deficiency in turfgrass production and management. This research did some surveys of systematic literature review about ...Improving turfgrass drought resistance and save-water features are very important to solve water deficiency in turfgrass production and management. This research did some surveys of systematic literature review about turfgrass drought tolerance morphological characteristics, physiological characteristics and water use efficiency, and provided the detailed information for enhancing turfgrass drought resistant and water use efficiency in the future.展开更多
Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the ni...Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.Candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.展开更多
Ulcerative colitis(UC)is a common progressive inflammatory disease whose incidence has increased rapidly in recent years,and can develop into colorectal cancer in severe cases.There are currently no adequate or effect...Ulcerative colitis(UC)is a common progressive inflammatory disease whose incidence has increased rapidly in recent years,and can develop into colorectal cancer in severe cases.There are currently no adequate or effective treatments for UC due to the fact that some patients have found suboptimal results after repeated administration,while others have experienced adverse effects.With the rapid development of nanotechnology,developing innovative colon-targeting platforms is essential to improving efficacy,reducing side effects,and improving patient compliance.In this review,we summarize the pathophysiological characteristics of UC and the most recent status of numerous nanodrug delivery systems based on different targeting mechanisms in treating UC.Oral,intravenous,and rectal drug delivery nanoparticles targeting the colon are discussed,which can provide ideas for the design of colon-targeting nanoparticles for the treatment of colon diseases,especially for the treatment of UC.Last but not least,we provide a glimpse into the future of colon-targeted delivery systems,as well as future advancements in the field.展开更多
Aims Woody plant encroachments in arid and semiarid ecosystems are widely reported but the physiological mechanisms still need to be further revealed.In the current study,we aim to determine whether differences in lea...Aims Woody plant encroachments in arid and semiarid ecosystems are widely reported but the physiological mechanisms still need to be further revealed.In the current study,we aim to determine whether differences in leaf physiological traits help explain grassland susceptibility to woody plant encroachment and whether distinctive physiological adaptations allow some shrub species to invade grasslands.Methods We compared physiological traits(photosynthesis,leaf water status,pigment compositions and leaf antioxidant capacities)of six species representing three functional groups:woody encroachers(Prosopis velutina,Larrea tridentata),woody non-encroachers(Acacia greggii,Lycium fremontii)and C4 grasses(Bouteloua curtipendula,Bouteloua barbata)which are naturally growing in a botanical garden in University of Arizona,USA.Important Findings We infer that P.velutina(encroacher)but not A.greggii or L.fremontii(non-encroachers)is encroaching in grasslands because the former species has higher water and light utilization efficiencies(instantaneous water use efficiency,instantaneous light use efficiency,and Fv/Fm).The extremely high carotenoid and total antioxidant capacity in its leaves appears to help the shrub L.tridentata(encroacher)survive high ambient oxidative damage caused by both drought and high light stresses in this grassland.The two C4 grass species,B.curtipendula and B.barbata,grow well in the arid ecosystem but may be susceptible to disturbances.展开更多
基金Supported by Hunan Provincial Postgraduate Education Innovation Project and Professional Ability Improvement Project (CX20211220)Scientific Research Project of Hunan Provincial Department of Education (20A278)+1 种基金Undergraduate Innovation and Entrepreneurship Training Program of Hunan Province (XJT[2021]197,No. 3705)School-level Postgraduate Innovation Experiment Project (24520012)。
文摘[Objectives]This study was conducted to investigate the toxicity of heavy metal antimony(Sb) to ramie(Boehmeria nivea(L.) Gaudich.) and the tolerance response in ramie. [Methods] A pot experiment was conducted to study the effects of Sb stress on root growth and Sb accumulation and transport of the root system of cultivated ramie Zhongzhu No.1, as well as on the physiological characteristics of ramie leaves. [Results] The plant height and root dry weight and volume of Zhongzhu No.1 showed an effect of "promoting at low concentrations and inhibiting at high concentrations" with the increase of Sb concentration, and decreased significantly at the concentration of 4 000 mg/kg, but no obvious toxic growth symptoms were observed. The content of Sb in roots(289.7-508.6 mg/kg) and the root-shoot transfer factor(0.09-0.57) of Zhongzhu No.1 increased with the increase of soil Sb concentration, but the change of Sb bioconcentration factor in roots was opposite, indicating that high concentrations of Sb in soil could promote the absorption of Sb in roots and the transport of Sb to the aboveground part, but the Sb enrichment capacity of roots was relatively reduced with the increase of soil Sb. Sb stress had a certain impact on the physiological characteristics of ramie leaves. With the increase of Sb treatment concentration, MDA, POD and SOD showed a change trend of "first increasing and then decreasing", while CAT gradually increased, indicating that Sb stress caused changes in the physiological characteristics of ramie leaves, thereby affecting plant growth and development. [Conclusions] This study provides a theoretical basis for ecological restoration of ramie in mining areas.
基金This work was supported by the Science Fund Project of Heilongjiang Province of China(ZD2020C004)the Special Fund for Basic Scientifi c research operation Fee of Central University(2572019CT02)+1 种基金the Innovation Project of State Key Laboratory of Tree Genetics and Breeding(Northeast Forestry University)(2019A03)Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team).
文摘Numerous growth and physiological variables of 3-week-old Populus simonii × P.nigra seedlings were assessed after treatment with either nitrate nitrogen(NO_(3)^(−)--N)(0.1,0.5,1,5,or 10 mmol·L^(−1)) or ammonium nitrogen(NH_(4)^(+)+-N)(0.1,0.5,1,5,or 10 mmol·L^(−1)) to determine the best nitrogen form and concentration to optimize growth,biomass allocation,pigment content,and photosynthetic capacity.The results of combining membership function and an evaluation index suggested that,5 mmol·L^(−1) nitrogen,regardless of the form,yielded the highest comprehensive evaluation index and good growth.In addition,a Pearson correlation analysis and network visualization revealed that the total mass,shoot mass,root mass,leaf dry mass,plant height,leaf area,chlorophyll a and total chlorophyll had a physiological index connectivity degree≥15 for both nitrogen forms.Net photosynthetic rate,stomatal conductance,transpiration rate,maximum photochemical efficiency of PSII,total nitrogen content,ground diameter,chlorophyll b,and carotenoid were unique indices for evaluating NH_(4)^(+)+-N-based nutrition,which could provide a theoretical basis for evaluating the effects of nitrogen fertilizer on seedlings,cultivation periods,and stress tolerance in P.simonii× P.nigra.
文摘The influence of a 40-fold attenuated geomagnetic field and its combined action with low doses of α- and γ-irradiation on the physiological characteristics of seeds of the highest plants and redox properties of water was investigated. It established the reduction of seed germination both under direct and indirect effects due to water action of attenuated geomagnetic field. A negative effect of hypomagnetic field on grown characteristics of seeds under indirect effect via water was decreased by the low doses of γ-irradiation, and was increased by low doses of α-irradiation, i.e. ionized radiation was the dominant factor in their combined action. It was revealed the increasing of the value of the oxidation-reduction potential of water under the influence of low-intensive α-ir-radiation (239Pu), γ-irradiation (137Cs) and also that the magnetic induction attenuated pointing to a natural decline. The increasing of the oxidation-reduction potential value testifies about “the regular decreasing of internal energy of water molecules” and the increasing of its oxidative properties, which, in our opinion, is caused the inhibition of the germination of seeds. It is supposed that namely water is the main component in the effects of studying factors on bio-objects, which acts due to the alterations of the properties and structural content of water.
基金Supported by National Key R&D Program of China(2018YFD100906-4)。
文摘Nitrogen plays a very important role in peanut nutrition and fertilization.For peanuts,the nitrogen nutrition comes from root nodules,soil and fertilizer,which are separately referred to as root nodule nitrogen,soil nitrogen and fertilizer nitrogen.The research obtained following findings.(ⅰ)The nitrogen supply ratio of the three nitrogen sources for peanut is about 5∶3∶2.There are significant differences in the nitrogen supply capacity of the three nitrogen sources.The root nodules have the largest variation in nitrogen fixation and have a high potential for development.Nitrogen fixation in root nodules is closely related to carbon metabolism indicators such as photosynthesis in peanut leaves.Phosphorus application could increase the accumulation of three nitrogen sources,and the increase in nodule nitrogen accumulation is greater than that of soil nitrogen and fertilizer nitrogen.(ⅱ)Nitrogen fertilizer has a significant effect on nitrogen nutrition of peanuts.Different forms of nitrogen fertilizers,such as amide nitrogen,ammonium nitrogen,nitrate nitrogen and mixed ammonium nitrate nitrogen,have significant effects on nitrogen metabolism and nitrogen accumulation in peanuts.Amide nitrogen fertilizer is beneficial to improving the activity of enzymes related to nitrogen metabolism and nitrogen accumulation.Controlled-release fertilizer can significantly increase the content of soluble protein and improve the activities of NRase,GDH,GS,GPT,etc.in roots and leaves at the pod setting and mature stages of peanuts,which is favorable for delaying the plant senescence and increasing the yield of peanuts.Mixed application of common nitrogen fertilizer and slow-release fertilizer can increase the soil nitrate nitrogen level at the later growth stage,which is beneficial to the development of the root system at the later stage of growth,increasing the distribution ratio of nitrogen in the pods,and also favorable for increasing the yield and nitrogen utilization rate.(ⅲ)Increasing the ploughing depth,improving fertilization methods,selecting nitrogen-efficient varieties,paying attention to foliar topdressing,and adopting fertilizer-water integrated cultivation are conducive to increasing the nitrogen utilization rate of peanuts,reducing the amount of nitrogen fertilizers,accordingly saving costs,increasing efficiency and realizing sustainable development of agricultural production.
基金Supported by National Natural Science Foundation of China (31000712)National Natural Science Fund (31000712)Yunnan Provincial Education Department Scientific Research Program (08Y0166)
文摘Experiments were conducted to evaluate the physiological and the biochemical characteristics of waxy wheat seeds under accelerated aging conditions. Five waxy wheat lines, which were Waxy 1, Waxy 4, Waxy 8, Waxy 9, and Waxy 15; and five non-waxy wheat lines: S-39, 04J89, Jan-81, Ⅲ42-4, and Ⅲ10 were studied. The seeds were subjected to accelerated aging at 40℃, 45℃, 50℃, 55℃, and 60℃, and 90% relative humidity for 0, 2, 4, 6, and 8 days, respectively. The results showed a gradual increase in conductivity and decrease in germination rate during accelerated aging. SOD, POD and CAT activities increased at low-grade treatment, but decreased at severe treatment. On the other hand, the soluble protein content decreased at 45℃, but successively increased, then decreased 50℃. From the above study, it showed that 90% RH at 55℃ was the best accelerated aging condition for optimum efficiency in a shorter period.
基金Supported by Doctoral Research Start-up Fund(BS514)Inner Mongolia Autonomous Region Science and Technology Reserve Project(2018MDCB02)+1 种基金Inner Mongolia Autonomous Region Science and Technology Planning Project(2018KJJH1702)Scientific Research Project of Inner Mongolia Minzu University(NMDSS2159)。
文摘[Objectives]This study was conducted to explore the mechanism of soybean cytoplasmic-nuclear male sterility.[Methods]With soybean cytoplasmic-nuclear male sterile line JLCMS9 A and its homotype maintainer line JLCMS9 B as experimental materials,the activity of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),malondialdehyde(MDA)content,starch content,soluble protein content,soluble sugar content and free proline content in flower buds,alabastrums and mature flowers were determined,and the contents and changes of auxin(IAA),gibberellin(GA3),isopentenyl adenosine(iPA)and abscisic acid(ABA)at the three stages were analyzed.[Results]The activity of SOD and CAT and the contents of MDA and free proline in the sterile line at the flower bud stage were lower than those of the maintainer line,but the opposite was true at the alabastrum stage and the flowering stage,and their values were higher than those of the maintainer line;the POD activity of the sterile line was significantly lower than that of the maintainer line at the flower bud stage,and the opposite was true at the alabastrum stage and the flowering stage,and its values were higher than those of the maintainer line;and the starch content and soluble sugar content of sterile line 9 A showed an overall upward trend,and were significantly lower than those of the maintainer line 9 B at the alabastrum stage and the flowering stage.During the whole development process of floral organs,the content of IAA in sterile line 9 A showed a trend of first increasing and then decreasing,and the content of iPA increased gradually.The contents of hormones in the sterile line were lower than those in the maintainer line.The ratios of IAA/ABA,IAA/GA3,IAA/iPA and ABA/GA3 in the sterile line were significantly different from those in the maintainer line.It is inferred that the abnormal physiological characteristics of floral organ development are related to the cytoplasmic-nuclear male sterility of soybean.The alabastrum stage may be a critical period for the occurrence of abnormal physiological and biochemical indexes in the floral organs of soybean cytoplasmic-nuclear male sterile lines.[Conclusions]This study provides a theoretical basis for the breeding of fine sterile lines of soybean and the research on the mechanism of sterility.
基金Supported by Project of National Natural Science Foundation(31501362)Natural Science Foundation Project of Guangxi(2014GXNSFBA118289,2014GXNSFAA118090)
文摘In order to study the effects of seed soaking with Paclobutrazol( PP333) on the tillering and physiological characteristics of sugarcane seedlings,sugar cane variety ROC22 was used as experimental material. The effects of seed soaking with different concentrations of PP333 were studied. The tiller number and growth of sugarcane were surveyed at the 6-leaf stage,the physiological indicators such as chlorophyll content,soluble protein content,proline content and peroxidase activity were measured at the 2-leaf,4-leaf,and 6-leaf stages. The results showed that the seed soaking with PP333 can effectively improve the tillering of sugarcane seedlings. The suitable concentration for the tillering of sugarcane and the growth and development of sugarcane was of 50 mg/L; the seed soaking with PP333 significantly increased the chlorophyll,soluble protein,proline,and peroxidase activity of leaves of sugarcane seedlings; the content of chlorophyll and soluble protein in leaves of sugarcane seedlings treated with 90 mg/L PP333 was the highest,and the proline content and peroxidase activity of sugarcane treated with 50 mg/L PP333 were the highest.
基金supported by the National Key Research and Development Program of China(2022YFD1500404)the National Natural Science Foundation of China(31801310)+1 种基金the Natural Science Projects of Universities in Jiangsu Province,China(21KJA210001)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China。
文摘Canopy temperature strongly influences crop yield formation and is closely related to plant physiological traits.However, the effects of nitrogen treatment on canopy temperature and rice growth have yet to be comprehensively examined. We conducted a two-year field experiment with three rice varieties(HD-5, NJ-9108, and YJ-805) and three nitrogen treatments(zero-N control(CK), 200 kg ha~(–1)(MN), and 300 kg ha~(–1)(HN)). We measured canopy temperature using a drone equipped with a high-precision camera at the six stages of the growth period. Generally,canopy temperature was significantly higher for CK than for MN and HN during the tillering, jointing, booting, and heading stages. The temperature was not significantly different among the nitrogen treatments between the milky and waxy stages. The canopy temperature of different rice varieties was found to follow the order: HD-5>NJ-9108>YJ-805, but the difference was not significant. The canopy temperature of rice was mainly related to plant traits, such as shoot fresh weight(correlation coefficient r=–0.895), plant water content(–0.912), net photosynthesis(–0.84), stomatal conductance(–0.91), transpiration rate(–0.90), and leaf stomatal area(–0.83). A structural equation model(SEM) showed that nitrogen fertilizer was an important factor affecting the rice canopy temperature.Our study revealed:(1) A suite of plant traits was associated with the nitrogen effects on canopy temperature,(2) the heading stage was the best time to observe rice canopy temperature, and(3) at that stage, canopy temperature was negatively correlated with rice yield, panicle number, and grain number per panicle. This study suggests that canopy temperature can be a convenient and accurate indicator of rice growth and yield prediction.
基金funded by the National Natural Science Foundation of China(U1803231,31860198,31060026)the Innovative Team Building Plan for Key Areas of Xinjiang Production and Construction Corps(2018CB003).
文摘Leaf traits can directly reflect the adaptation strategies of plants to the environment.However,there is limited knowledge on the adaptation strategies of heteromorphic leaves of male and female Populus euphratica Oliv.in response to individual developmental stages(i.e.,diameter class)and canopy height changes.In this study,morphological and physiological properties of heteromorphic leaves of male and female P.euphratica were investigated.Results showed that both male and female P.euphratica exhibited increased leaf area(LA),leaf dry weight(LDW),leaf thickness(LT),net photosynthetic rate(P_(n)),transpiration rate(T_(r)),stomatal conductance(g_(s)),proline(Pro),and malondialdehyde(MDA)concentration,decreased leaf shape index(LI)and specific leaf area(SLA)with increasing diameter and canopy height.Leaf water potential(LWP)increased with increasing diameter,LWP decreased significantly with increasing canopy height in both sexes,and carbon isotope fraction(δ^(13)C)increased significantly with canopy height in both sexes,all of which showed obvious resistance characteristics.However,males showed greater LA,LT,P_(n),T_(r),and Pro than females at the same canopy height,and males showed significantly higher LA,SLA,LT,P_(n),T_(r),g_(s),and MDA,but lower LWP and δ_(1)3C than females at the same canopy height,suggesting that male P.euphratica have stronger photosynthetic and osmoregulatory abilities,and are sensitive to water deficiency.Moreover,difference between male and female P.euphratica is closely related to the increase in individual diameter class and canopy height.In summary,male plants showed higher stress tolerance than female plants,and differences in P_(n),g_(s),T_(r),Pro,MDA,δ_(13)C,and LWP between females and males were related to changes in leaf morphology,diameter class,and canopy height.The results of this study provide a theory for the differences in growth adaptation strategies during individual development of P.euphratica.
基金This research is supported by the Key Research and Development Projects of Zhejiang Province(2020C02030,2015C02030)Shanxi Province(2019TSLSF02-01-01)+2 种基金The National Natural Science Foundation of China(81673537)Public Projects of Zhejiang Province of China(2017C37098)Science Public Welfare Fund Projects of Zhejiang Province(2017C32050).
文摘This study aimed to explore the cold tolerance of two cultivars of Dendrobium officinale(MG1,MG2)grown in different regions of China.Under-2℃ incubation,cultivar MG1 remained active after 3 d,and continued to grow after returning to room temperature.However,MG2 could only maintain its activity after 2 d treatment at−2℃,and the seedlings died with the low temperature treatment time.Investigation of the characteristics of the plants grown in the south(Hangzhou)or north(Zhengzhou)of China indicated that the leaves of MG1 also had reduced stomatal density,the highest thickness,and a compact microstructure.The contents of proline and soluble sugars were higher in MG1 than those in MG2.The cultivar MG1 had higher SOD enzyme activity than MG2,while CAT and POD activities in samples from Zhengzhou were higher than those from Hangzhou.The contents of polysaccharides and alkaloids in stems of in MG1 were higher than those in MG2,while the content of flavonoids in the Zhengzhou samples was higher than that in the Hangzhou samples.In addition,plant heights,stem diameters,and chlorophyll content were higher in MG1.Overall,MG1 had better cold resistance than MG2.MG1 is a cold tolerant cultivar with thick leaves and reduced stomatal density,higher contents of soluble sugars,proline,CAT,POD,polysaccharides,flavonoids and alkaloids,which together make it more adaptable to low temperatures.Thus,the cultivar MG1,with its demonstrated cold tolerance,can accordingly be grown on a large scale in cold regions,thereby expanding the available planting area for this important traditional medicinal plant to meet the increasing commercial demand for it.
基金Supported by Research and Development Program of Gansu Province(17YF1FA113)The National Natural Science Foundation of China(31560128).
文摘[Objectives]This study was conducted to investigate the photosynthetic physiological characteristics of Populus euphratica trees at different forest ages in the desert area of Minqin in response to drought stress.[Methods]With P.euphratica trees of different ages in Minqin as the research object,the water characteristics and photosynthetic physiological indexes(chlorophyll,soluble sugar,POD,SOD and MDA)were compared under different conditions.[Results]On the time gradient,the soil water contents of P.euphratica of different ages decreased continuously with the extension of irrigation stop time,but the decreases were small.Under the same stress treatment,the soil water contents of P.euphratica of different ages increased with the deepening of soil layer,but the differences were not significant(P>0.05).Under normal condition,the chlorophyll contents of P.euphratica at three ages gradually increased with the increase of age.The chlorophyll contents in leaves of P.euphratica at different ages were all lower under normal condition and higher under water stress.The changes of POD and SOD activity in leaves of P.euphratica at different ages under different conditions were basically the same,showing that the enzyme activity was higher under water stress than under normal under.The MDA contents in leaves of the young and middle P.euphratica forests were higher under water stress at 7 and 21 d than under normal condition,and the differences were not significant(P>0.05);and the MDA content in leaves of the mature P.euphratica forest was higher under water stress at 21 and 35 d than under normal condition.Drought stress has a certain effect on the photosynthetic physiological characteristics of P.euphratica.In summary,under drought stress,the chlorophyll content,SOD and POD activity,and MDA molar concentration in the leaves of P.euphratica were basically higher than under normal condition,indicating that P.euphratica could resist drought environment through osmotic adjustment and showed strong drought resistance.[Conclusions]This study provides a theoretical reference for the restoration,protection and reconstruction of natural P.euphratica forests in the desert area of Minqin.
文摘The physiological properties of new compact vertical-leaf type varieties,such as corn Zhengdan 958,Xundan 18,Jidan 7,etc.were analyzed in order to provid references for its large extension and new high-yield breeding.Results showed that reasons of high-yield included reasonable indices of leaf-area changing,long keeping of corn leaves and slow aging.Photosynthetic pigment,protein and soluble sugar in varietal leaves were high with the high peroxide enzyme activation,photosynthesis inherent ability and photosynthesis eff iciency,but with low malondialdehyde.The volume of grain seed was big,with long forming or starch grouting time of cells and the weight of thousand-granules was high.It indicated that Zhengdan 958 was still the best corn variety for the extensive utilization.The seeds production should pay attention to keep the pure degree and the hallmark for giving full potential advantages on the yield of these species.
基金sponsored by Science and Technology Power Economy 2020 (2020YFF0426562-2).
文摘To address problems caused by rice machine transplanting such as injury to the seedlings and recovery period that extend growth period,this study explored the effects of different machine transplanting methods on the physiological and yield characteristics of late rice in China,and determine the appropriate machine transplanting method for late rice,which was expected to provide a basis for high-yield and high-efficient cultivation of machine-transplanted late rice.Hybrid indica rice Taiyou 398 and conventional indica rice Jing Gangruanzhan were selected as the research objects,and large-pot carpet seedling machine transplanting(M1),conventional pot carpet seedling machine transplanting(M2)and ordinary carpet seedling machine transplanting(M3)were adopted respectively to analyze their effects on seedling quality,population physiological characteristics,yield and its components and economic benefits of late rice.The results showed that compared with M2 and M3,M1 achieved higher seedling quality,showing significant advantages in the early stage despite average root entwining force that met the requirement of machine transplanting.The seedlings transplanted using M1 had shorter recovery period after mechanical transplanting,with earlier tillering,earlier peak seedling,and slower declining of stems and tillers in the late stage;the peak seedling number was not high,but the effective tiller number and earbearing tiller percentage were significantly higher than those achieved by the other two machine transplanting methods.Also,M1 achieved stronger photosynthetic capacity of flag leaves before HS,with more photosynthetic products in stems and leaves transported to panicles and more efficiently after HS.Compared with seedlings transplanted using M2 and M3,the recovery period of those transplanted using M1 was shortened by 3 and 5 d,the heading stage(HS),and maturity stage(MS)were advanced,which effectively reduced the risk and impact of“cold dew wind”on machine-transplanted late rice.M1 had significant yield increase advantage and economic benefit,with better grain maturity,and“larger panicles,more panicles,more and fuller grains”.M1 achieved an average yield increase of 10.31%-11.10%,20.67%-25.10%in 2 years,and an average income increase of 18.65%-131.06%and 62.85%-323.78%,respectively.Therefore,vigorously developing M1 is the key to the high-yield and high-efficient cultivation of machine-transplanted late rice in China.
基金the Natural Science Foundation of China(No.31771735,No.31971855)the Natural Science Foundation of Hubei Province(No.2019CFB273)Science and Technology Innovation Project from the Chinese Academy of Agricultural Sciences(CAASASTIP-2016-OCRI)。
文摘AM1(ABA-mimicking ligand)is a newly identified signaling molecule for plants during drought tolerance.To investigate the potential role of AM1 in response of rapeseed to drought stress,we conducted experiments by growing rapeseed plants under different levels of drought stress with or without applying AM1 or ABA in a rain shelter.The results indicated that drought significantly inhibited rapeseed growth by damaging the photosyn-thesis system,increasing active oxygen accumulation,destroying the oxidative system,and worsening membrane lipid peroxidation.Exogenously applied AM1 and ABA both relieved the damage to rapeseed that was induced by drought stress.Compared with the drought-treated rapeseed,the AM1 treatment significantly improved plant height,number of greelp leaves,root collar thickness,leaf area,dry matter weight,and root cap ratios of rapeseed.In addition,Pn,Gs,Ci,Tr were significantly increased by the AM1 treatment.The AM1 treatment also alleviated the drought induced reductions in Fv/Fm,ΦPSII,qN and ETR;induced an increase in NPQ;and resulted in decreased active oxygen accumulation and membrane lipid peroxidation.Although the ABA treatment relieved photosynthetic fluorescence and antioxidation system parameters to some extent,the effect was inferior to AM1 treatment.Yield under AM1 treatment was higher than that under ABA treatment but was still far lower than that of normal water supply control.In summary,AM1 is functionally similar to ABA in terms of drought relief and regulation,moreover has a better effect.
基金This study was supported by the Major Special Projects for the Cultivation of New National Genetically Modified Varieties(Contract No.2016ZX08010013-002)the Guizhou Science and Technology Plan Project(Contract No.[2016]7449)the Talent Training Program of Guizhou University(Contract No.[2018]5781).
文摘Quinolinate phosphoribosyltransferase(QPRTase),a key enzyme in ensuring nicotinic acid is available for the synthesis of defensive pyridine alkaloids in Nicotiana species,also plays an important role in nicotinamide adenine dinucleotide(NAD)biosynthesis.In this study,the morphological traits,the quality characteristics and photosynthetic parameters in QPT-overexpressing/interfering tobacco plants were investigated,respectively.Results showed that the interference of QPT gene not only reduced significantly the morphological traits including plant height,stem girth,leaf number and leaf length,etc.at 20 days after transplanting(DAT),but the flowering period was delayed 10-15 d in interfered tobaccos compared with the overexpressed,control and wild-type counterparts.However,at 40 DAT and 60 DAT,only three indexes(plant height,stem girth and leaf number)in QPT-interfering plants appeared significant difference in comparison with other three types of tobacco lines.Meanwhile,the determination results from nicotine,sugar,K+and Cl-content showed the nicotine content in interfered plants was always significantly lower than that in overexpressed plants,control and the wild-type ones respectively whatever toppling or not.At the same time,the toppling treatment also caused the increasement of K+content among the four different tobacco lines,but the maximum increase amplitude of K+content was found in QPT-overexpressing tobaccos while the minimum appeared in QPT-interfering plants.Finally,QPT-interference in transgenic tobaccos likewise affected the photosynthesis by reducing net photosynthetic rate(Pn),stomata conductance(Gs)and transpiration rate(Tr),while there was no significant difference between QPT-overexpressing plants and the controls and the wild-types.
基金Supported by Key Technology R&D Program of Hubei Province(2013BBB24)Second Survey of Key Wild Plant Resources under Protection in China"Special Survey of Phoebe zhennan S.Lee Resources in Hubei Province"
文摘Transplantation experiment was carried out using biennial container seedlings and bare root seedlings of Phoebe zhennan S. Lee as materials. In the experiment,it measured the growth indicators such as the seedling height,basal diameter,and number of branches and leaves. Besides,it also measured net photosynthetic rate( Pn),transpiration rate( Tr),stomatal conductance( Gs),intercellular CO_2 concentration( Ci) and soluble sugar,soluble protein,malondialdehyde( MDA) content,superoxide dismutase activity and root activity. The results indicated that the growth indicators of the Phoebe container seedlings performed the best in the plant height,basal diameter,and number of branches and leaves; photosynthetic capacity was the strongest,and the fertilization could enhance the photosynthetic capacity of seedlings; soluble sugar,soluble protein content,superoxide dismutase activity and root activity of Phoebe container seedlings were higher than that of bare root seedlings.
基金Supported by the National Nature Science Foundation (30871735 31272191)
文摘Improving turfgrass drought resistance and save-water features are very important to solve water deficiency in turfgrass production and management. This research did some surveys of systematic literature review about turfgrass drought tolerance morphological characteristics, physiological characteristics and water use efficiency, and provided the detailed information for enhancing turfgrass drought resistant and water use efficiency in the future.
基金supported by the National Natural Science Foundation of China(No.52070162)。
文摘Anammox bacteria grow slowly and can be affected by large pH fluctuations.Using suitable buffers could make the start-up of anammox reactors easy and rapid.In this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were investigated.Reactors with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox activity.Reactors with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),respectively.Candidatus Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic conditions.These findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.
基金financially supported by Beijing Nova Program(Nos.Z211100002121127 and 20220484219)Beijing Natural Science Foundation(No.L212059)+1 种基金Fundamental Research Funds for the Central Universities(No.3332021101)CAMS Innovation Fund for Medical Sciences(CIFMS,Nos.2021-I2M-1-026 and 2021-I2M-1-028).
文摘Ulcerative colitis(UC)is a common progressive inflammatory disease whose incidence has increased rapidly in recent years,and can develop into colorectal cancer in severe cases.There are currently no adequate or effective treatments for UC due to the fact that some patients have found suboptimal results after repeated administration,while others have experienced adverse effects.With the rapid development of nanotechnology,developing innovative colon-targeting platforms is essential to improving efficacy,reducing side effects,and improving patient compliance.In this review,we summarize the pathophysiological characteristics of UC and the most recent status of numerous nanodrug delivery systems based on different targeting mechanisms in treating UC.Oral,intravenous,and rectal drug delivery nanoparticles targeting the colon are discussed,which can provide ideas for the design of colon-targeting nanoparticles for the treatment of colon diseases,especially for the treatment of UC.Last but not least,we provide a glimpse into the future of colon-targeted delivery systems,as well as future advancements in the field.
基金National Natural Science Foundation of China(30901148).
文摘Aims Woody plant encroachments in arid and semiarid ecosystems are widely reported but the physiological mechanisms still need to be further revealed.In the current study,we aim to determine whether differences in leaf physiological traits help explain grassland susceptibility to woody plant encroachment and whether distinctive physiological adaptations allow some shrub species to invade grasslands.Methods We compared physiological traits(photosynthesis,leaf water status,pigment compositions and leaf antioxidant capacities)of six species representing three functional groups:woody encroachers(Prosopis velutina,Larrea tridentata),woody non-encroachers(Acacia greggii,Lycium fremontii)and C4 grasses(Bouteloua curtipendula,Bouteloua barbata)which are naturally growing in a botanical garden in University of Arizona,USA.Important Findings We infer that P.velutina(encroacher)but not A.greggii or L.fremontii(non-encroachers)is encroaching in grasslands because the former species has higher water and light utilization efficiencies(instantaneous water use efficiency,instantaneous light use efficiency,and Fv/Fm).The extremely high carotenoid and total antioxidant capacity in its leaves appears to help the shrub L.tridentata(encroacher)survive high ambient oxidative damage caused by both drought and high light stresses in this grassland.The two C4 grass species,B.curtipendula and B.barbata,grow well in the arid ecosystem but may be susceptible to disturbances.
