[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effect...[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effects were observed 5, 10, 15 and 30 d after drug application, with the remained weeds surveyed 15 and 30 d after drug application. [Result] The test showed pyrazosulfuron-ethyl·quinclorac 50%WP was safe to rice as treatment agent of stem and leaf, and rice yield increased dramatical y, with the growth rate in 2.1%-49.3%. After the drug application, the prevention effects on Echinochloa crusgal i, Ludwimlia prostrata, Monochoria vamli-nalis, and Zong grass were 92.2%, 96.6%, 93.5%, and 94.8%, and the effects on fresh weight were 94.8%, 97.1%, 93.3% and 94.9%, respectively. [Conclusion] Pyra-zosulfuron-ethyl·quinclorac 50% WP can be taken as treatment agents of stem and leaf of dry direct seeded rice.展开更多
Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing meth...Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing method does not facilitate mechanization during sowing.The objective of this study was to determine if single-seed sowing at a proper seeding rate yielded better than traditional double-seed sowing pattern and the differences of physiological metabolism of roots.A field experiment was conducted in two consecutive years to compare pod yields of single-seed sowing at 180000(S180),225000(S225),and 270000 seeds ha^-1(S270)with that of double-seed sowing at 270000 seeds ha^-1(D270)using a completely randomized block design with four replications.And the root bleeding sap rate,nutrient content,and the main hormone contents in root bleeding sap were also comparatively investigated.Although the pod yields of single-seed sowing at the three densities were higher than that of traditional double-seed sowing(D270),S225 yielded better than the other two single-seed sowing treatments(S180 and S270).The increased pod yield in single-seed sowing at 225000 seeds ha^-1 was mainly due to the higher pod dry weight per plant and harvest index.The improved pod dry weight and shoot growth had closely relationship with the enhanced root physiological traits such as the increased root bleeding sap rate,content of free amino acids,soluble sugars,K^+,Mg^2+,Zn^2+,and Ca^2+of the individual plant root.The improved activity of root reductive,nitrate reductase(NR)and ATPase and higher zeatin and zeatin riboside(Z+ZR)content of root bleeding sap were alsocrucial to the pod and shoot growth of peanut.Single-seed sowing at a moderate seeding rate(S225)is a potential practice to increase pod yield and to save seed cost.展开更多
Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, th...Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.展开更多
Mechanical hill wet-seeded rice machine is beneficial for establishing and growing uniform rows of seedlings.However,there is limited knowledge regarding the effects of the establishment of furrows on growth,lodging a...Mechanical hill wet-seeded rice machine is beneficial for establishing and growing uniform rows of seedlings.However,there is limited knowledge regarding the effects of the establishment of furrows on growth,lodging and yield,and their relationships with root traits.In this study,field experiments were conducted during 2012 and 2013 using two super rice varieties(hybrid rice Peizataifeng and inbred rice Yuxiangyouzhan)under three furrow establishment treatments(T1,both water and seed furrows were established by the machine;T2,only seed furrows were established by the machine;and T3,neither water nor seed furrows were established by the machine).Lodging index,lodging-related traits,grain yield,above-ground dry weight and root traits were measured.The results showed that the lodging index was significantly affected by the treatments with furrows(T1 and T2).The strongest lodging resistance was detected in the mechanical hill wet-seeded rice with furrow treatment(T1)in both 2012 and 2013.Lodging resistance was strongly related to the breaking resistance.No significant difference was found in grain yield or dry weight of the mechanical hill wet-seeded rice.Therefore,the mechanical hill wet-seeded rice with furrow treatment increased rice lodging resistance,which was related to root traits.展开更多
An open-top chamber experiment was conducted at the University of Michigan Biological Station near Pellston, Michigan, USA, to study the effects of soil fertility and CO2 on leaf, stem and root dark respiration (Rd) o...An open-top chamber experiment was conducted at the University of Michigan Biological Station near Pellston, Michigan, USA, to study the effects of soil fertility and CO2 on leaf, stem and root dark respiration (Rd) of Populus tremuloides. Overall, area-based day-time leaf Rd (Rda) was significantly greater at elevated than at ambient CO2 in high-fertility soil, but not in low-fertility soil. Mass-based leaf Rd (Rdm) was overall greater for high- than for low-fertility soil grown trees at elected, but not at ambient CO2. Nighttime leaf Rd. and Rdm were unthected by soil fertility or CO2, nor was stem Rda, which ranged from 1.0 to 1.4 μmol m-2 s-1 in the spring and 3.5 to 4.5 μmol m-2 s-1 in the summer. Root Rda. was significantly higher in high- than in low-fertility soil, but was unaffected by CO2. Since biomass production of P. tremuloides will be significantly greater at elevated CO2 while specific Rd will either increase or remain unchanged, we predict that carbon loss to the atmosphere through respiration from this ecologically important species would increase at higher CO2. Soil fertility would also interact with elevated CO2 in affecting the carbon flow in the plant-soil-air system.展开更多
Nerve grafting has always been necessary when the contralateral C7 nerve root is transferred to treat brachial plexus injury. Acellular nerve allograft is a promising alternative for the treatment of nerve defects, an...Nerve grafting has always been necessary when the contralateral C7 nerve root is transferred to treat brachial plexus injury. Acellular nerve allograft is a promising alternative for the treatment of nerve defects, and results were improved by grafts laden with differentiated adipose stem cells. However, use of these tissue-engineered nerve grafts has not been reported for the treatment of brachial plexus injury. The aim of the present study was to evaluate the outcome of acellular nerve allografts seeded with differentiated adipose stem cells to improve nerve regeneration in a rat model in which the contralateral C7 nerve was transferred to repair an upper brachial plexus injury. Differentiated adipose stem cells were obtained from Sprague-Dawley rats and transdifferentiated into a Schwann cell-like phenotype. Acellular nerve allografts were prepared from 15-mm bilateral sections of rat sciatic nerves. Rats were randomly divided into three groups: acellular nerve allograft, acellular nerve allograft + differentiated adipose stem cells, and autograft. The upper brachial plexus injury model was established by traction applied away from the intervertebral foramen with micro-hemostat forceps. Acellular nerve allografts with or without seeded cells were used to bridge the gap between the contralateral C7 nerve root and C5–6 nerve. Histological staining, electrophysiology, and neurological function tests were used to evaluate the effect of nerve repair 16 weeks after surgery. Results showed that the onset of discernible functional recovery occurred earlier in the autograft group first, followed by the acellular nerve allograft + differentiated adipose stem cells group, and then the acellular nerve allograft group;moreover, there was a significant difference between autograft and acellular nerve allograft groups. Compared with the acellular nerve allograft group, compound muscle action potential, motor conduction velocity, positivity for neurofilament and S100, diameter of regenerating axons, myelin sheath thickness, and density of myelinated fibers were remarkably increased in autograft and acellular nerve allograft + differentiated adipose stem cells groups. These findings confirm that acellular nerve allografts seeded with differentiated adipose stem cells effectively promoted nerve repair after brachial plexus injuries, and the effect was better than that of acellular nerve repair alone. This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University of China(approval No. 2016-150) in June 2016.展开更多
The root of Scutellaria baicalensis Georgi is traditionally used as medicine,and it has been confirmed that S.baicalensis Georgi has flavonoid chemical constituents,pharmacological activity and cosmetic efficacy.With ...The root of Scutellaria baicalensis Georgi is traditionally used as medicine,and it has been confirmed that S.baicalensis Georgi has flavonoid chemical constituents,pharmacological activity and cosmetic efficacy.With the extensive application of S.baicalensis Georgi roots,the resource of S.baicalensis Georgi has been increasingly short.The above-ground part of stems and leaves of S.baicalensis Georgi has also been gradually recognized and developed.Studies have found that the chemical constituents from stems and leaves of S.baicalensis Georgi are also a group of flavonoids with a lot of pharmacological activity and have a great application value.Based on this,the present review will be reported on the chemical constituents and application of the roots,stems and leaves of S.baicalensis Georgi.展开更多
The present study, conducted during 2016 and 2017 seasons, aimed to investigate the effect of IBA on rooting of Piper betle L. stem cuttings (softwood and semi-hardwood). The experiment was undertaken in misting house...The present study, conducted during 2016 and 2017 seasons, aimed to investigate the effect of IBA on rooting of Piper betle L. stem cuttings (softwood and semi-hardwood). The experiment was undertaken in misting house field 2 UPM using the sand media to determine the adventitious roots initiation and development using the histological method. The cuttings were treated with different IBA concentrations (0, 500, 1000, 1500 and 2000 mg/L). The nodes explants were used in the development of a protocol for in vitro propagation of P. betle L., with different concentrations of Clorox with different times of immersion (20% Clorox 10 minutes, 30% Clorox 10 minutes, 20% Clorox 20 minutes, and 30% 20 minutes). In multiplication of the plantlets, Murashige and Skoog (MS) medium with different concentrations of BAP (0, 0.5, 1.0, 2.0 mg/L) were used to investigate the rooting of the explants. The results indicated that the types of the cuttings were different in the rooting capacity and the length of the roots. Moreover, it was found that in comparison with the control treatment, by a rise in the concentrations of the IBA, there was a significant upsurge in the rooting percentage, the root diameter, and the number of the roots. The results indicated that the types of cutting with 1000, 1500 and 2000 mg/L IBA perform better in the root percentage (100%) in the semi hardwood cuttings. The best results, however, were 2000 mg/L IBA in the semi hardwood cuttings, with the number of the roots to be 35.05, and the fresh weight of the roots to be 3.94 g, the dry weight of the roots to be 0.33 g, the length of the roots to be 391.88 cm, the roots diameter to be 1.21 mm, the surface area of the roots to be 121.83 cm2, and the root volume to be 2.99 cm3. Nonetheless, the optimal concentration of Clorox with the time immersion was 20% with the 20-minute immersion time, which produced a shoot induction percentage of 30% dead explants and a mean number of 70.00 shoots per explant and the optimal concentration of benzylaminopurine (BAP) at 1.0 mg/L. It is of note that a shoot induction percentage of 22.29% and a mean number of 4.1% number of auxiliary bud per treatment. P. betle shoots in MS medium without PGR MS (0.0) yielded a good rooting.展开更多
Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bot...Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bottleneck for its long-term sustainability. Investigating the transpiration of seed-maize plants will offer valuable information for suitable planting and irrigation strategies in this arid area. In this study, stem flow was measured using a heat balance method under alternate furrow irrigation and double-row ridge planting. Meteorological factors, soil water content (e), soil temperature (Ts) and leaf area (LA) were also monitored during 2012 and 2013. The diurnal stem flow and seasonal dynamics of maize plants in the zones of south side female parent (SFP), north side female parent (NFP) and male parent (MP) were investigated. The order of stem flow rate was: SFP〉MP〉NFP. The relationships between stem flow and influential factors during three growth stages at different time scales were analyzed. On an hourly scale, solar radiation (Rs) was the main driving factor of stem flow. The influence of air temperature (Ta) during the maturity stage was significantly higher than in other periods. On a daily scale, Rs was the main driving factor of stem flow during the heading stage. During the filling growth stage, the main driving factor of NFP and MP stem flow was RH and Ts, respectively. However, during the maturity stage, the environ- mental factors had no significant influence on seed-maize stem flow. For different seed-maize plants, the main influential factors were different in each of the three growing seasons. Therefore, we identified them to accurately model the FP and MP stem flow and applied precision irrigation under alternate partial root-zone furrow irrigation to analyze major factors affecting stem flow in different scales.展开更多
It was hypothesized that mesenchymal stem cells(MSCs) could provide necessary trophic factors when seeded onto the surfaces of commonly used nerve graft substitutes. We aimed to determine the gene expression of MSCs w...It was hypothesized that mesenchymal stem cells(MSCs) could provide necessary trophic factors when seeded onto the surfaces of commonly used nerve graft substitutes. We aimed to determine the gene expression of MSCs when influenced by Avance■ Nerve Grafts or Neura Gen■ Nerve Guides. Human adipose-derived MSCs were cultured and dynamically seeded onto 30 Avance■ Nerve Grafts and 30 Neura Gen■ Nerve Guides for 12 hours. At six time points after seeding, quantitative polymerase chain reaction analyses were performed for five samples per group. Neurotrophic [nerve growth factor(NGF), glial cell line-derived neurotrophic factor(GDNF), pleiotrophin(PTN), growth associated protein 43(GAP43) and brain-derived neurotrophic factor(BDNF)], myelination [peripheral myelin protein 22(PMP22) and myelin protein zero(MPZ)], angiogenic [platelet endothelial cell adhesion molecule 1(PECAM1/CD31) and vascular endothelial cell growth factor alpha(VEGFA)], extracellular matrix(ECM) [collagen type alpha I(COL1A1), collagen type alpha III(COL3A1), Fibulin 1(FBLN1) and laminin subunit beta 2(LAMB2)] and cell surface marker cluster of differentiation 96(CD96) gene expression was quantified. Unseeded Avance■ Nerve Grafts and Neura Gen■ Nerve Guides were used to evaluate the baseline gene expression, and unseeded MSCs provided the baseline gene expression of MSCs. The interaction of MSCs with the Avance■ Nerve Grafts led to a short-term upregulation of neurotrophic(NGF, GDNF and BDNF), myelination(PMP22 and MPZ) and angiogenic genes(CD31 and VEGFA) and a long-term upregulation of BDNF, VEGFA and COL1A1. The interaction between MSCs and the Neura Gen■ Nerve Guide led to short term upregulation of neurotrophic(NGF, GDNF and BDNF) myelination(PMP22 and MPZ), angiogenic(CD31 and VEGFA), ECM(COL1A1) and cell surface(CD96) genes and long-term upregulation of neurotrophic(GDNF and BDNF), angiogenic(CD31 and VEGFA), ECM genes(COL1A1, COL3A1, and FBLN1) and cell surface(CD96) genes. Analysis demonstrated MSCs seeded onto Neura Gen■ Nerve Guides expressed significantly higher levels of neurotrophic(PTN), angiogenic(VEGFA) and ECM(COL3A1, FBLN1) genes in the long term period compared to MSCs seeded onto Avance■ Nerve Grafts. Overall, the interaction between human MSCs and both nerve graft substitutes resulted in a significant upregulation of the expression of numerous genes important for nerve regeneration over time. The in vitro interaction of MSCs with the Neura Gen■ Nerve Guide was more pronounced, particularly in the long term period(> 14 days after seeding). These results suggest that MSC-seeding has potential to be applied in a clinical setting, which needs to be confirmed in future in vitro and in vivo research.展开更多
The use of iodine-125 (L251) in cancer treatment has been shown to relieve patients' pain. Consid- ering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, ...The use of iodine-125 (L251) in cancer treatment has been shown to relieve patients' pain. Consid- ering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we assumed that 125I could be implanted into rat dorsal root ganglia to provide relief for neuropathic pain. 125I seeds with different radioactivity (0, 14.8, 29.6 MBq) were im- planted separately through L4-5 and L5-6 intervertebral foramen into the vicinity of the L5 dorsal root ganglion, von Frey hair results demonstrated the mechanical pain threshold was elevated after implanting 125I seeds from the high radioactivity group. Transmission electron microscopy revealed that nuclear membrane shrinkage, nucleolar margination, widespread mitochondrial swelling, partial vacuolization, lysosome increase, and partial endoplasmic reticulum dilation were visible at 1,440 hours in the low radioactivity group and at 336 hours in the high radio- activity group. Abundant nuclear membrane shrinkage, partial fuzzy nuclear membrane and endoplasmic reticulum necrosis were observed at 1,440 hours in the high radioactivity group. No significant difference in combined behavioral scores was detected between preoperation and postoperation in the low and high radioactivity groups. These results suggested that the mechan- ical pain threshold was elevated after implanting 125I seeds without influencing motor functions of the hind limb, although cell injury was present.展开更多
An experimental model of brachial plexus root avulsion injury of cervical dorsal C5-6 was established in adult and neonatal rats.Real-time PCR showed that the levels of brain-derived neurotrophic factor,nerve growth f...An experimental model of brachial plexus root avulsion injury of cervical dorsal C5-6 was established in adult and neonatal rats.Real-time PCR showed that the levels of brain-derived neurotrophic factor,nerve growth factor and neurotrophin-3 in adult rats increased rapidly 1 day after brachial plexus root avulsion injury,and then gradually decreased to normal levels by 21 days.In neonatal rats,levels of the three neurotrophic factors were decreased on the first day after injury,and then gradually increased from the seventh day and remained at high levels for an extended period of time.We observed that greater neural plasticity contributed to better functional recovery in neonatal rats after brachial plexus root avulsion injury compared with adult rats.Moreover, immunohistochemical staining showed that the number of bromodeoxyuridine/nestin-positive cells increased significantly in the spinal cords of the adult rats compared with neonatal rats after brachial plexus root avulsion injury.In addition,the number of bromodeoxyuridine/glial fibrillary acidic protein-positive cells in adult rats was significantly higher than in neonatal rats 14 and 35 days after brachial plexus injury.Bromodeoxyuridine/β-tubulin-positive cells were not found in either adult or neonatal rats.These results indicate that neural stem cells differentiate mainly into astrocytes after brachial plexus root avulsion injury.Furthermore,the degree of neural stem cell differentiation in neonatal rats was lower than in adult rats.展开更多
[Objectives] This study was conducted to investigate the effects of different treatments on rooting and germination of Paeonia rockii T. Hong et J.J.Li seeds. [Methods] Different stratification time and temperatures a...[Objectives] This study was conducted to investigate the effects of different treatments on rooting and germination of Paeonia rockii T. Hong et J.J.Li seeds. [Methods] Different stratification time and temperatures and different GA_3 concentrations and treatment time were set to screen the optimum treatment method for promoting seed rooting and germination. [Results] The rooting rate was the highest when the seeds were subjected to 30 d of stratification treatment in an incubator at 25℃, and treated with 300 mg/L GA_3 for 24 h. Soaking the seeds with 300 mg/L GA_3 for 24 h combined with 30 d of stratification treatment was most beneficial to germination, and the germination rate was over 90%. [Conclusions] This study provides technical guidance and basic information for the rooting and germination of P. rockii seeds.展开更多
A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and fo...A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.展开更多
Tomatoes are one of the main vegetables in the food industry that are consumed fresh and processed. A multi-element microanalysis was performed with the use of scanning electron microscopy (SEM) in conjunction with en...Tomatoes are one of the main vegetables in the food industry that are consumed fresh and processed. A multi-element microanalysis was performed with the use of scanning electron microscopy (SEM) in conjunction with energy dispersion spectroscopy (EDS), to see changes in nutrient concentration in roots and leaves, as well as fresh and dry biomass in tomato seedlings. Exposed in nutrient solution (NS) with different levels of Ca (control, 25, 50 and 100 mM). The root was put in also<span lang="EN-US" style="font-size:10pt;font-family:;" "=""> </span><span lang="EN-US" style="font-size:10pt;font-family:;" "="">to H<sub>2</sub>O<sub>2</sub> for 8 hours to observe the changes that occurred. It was observed that NS with 100 mM Ca in fresh stem biomass and fresh leaf biomass increased by 25% and 38% compared to the control. It was observed that the NS with 100 and 50 mM of Ca, the content of Ca and Cl in foliar tissue increased by 34.50% and 13.15% compared to the control. Treatment with H<sub>2</sub>O<sub>2</sub> and with 25 and 100 mM of Ca at NS increased the height of the seedling and fresh leaf bio-mass by 19.75% and 60.80% compared to the control. The treatment with H<sub>2</sub>O<sub>2</sub> and with the different levels of Ca in the NS increased the content of C, P, K, Ca and Cl in the leaf tissue. Only S was significant for the control. Treatment with H<sub>2</sub>O<sub>2</sub> and 100 mM Ca in the NS increased Ca and Mg by 83.48% and 40.47% for the root compared to the control. The K and Cl in the root was higher in the control treatment by 47.61% and 55% respect to the highest level of Ca.</span><span lang="EN-US" style="font-size:10pt;font-family:;" "=""> </span><span lang="EN-US" style="font-size:10pt;font-family:;" "="">It is concluded that multielemental microanalysis is a powerful, non-destructive, fast and accurate tool for the determination of plant nutrients. Also, it is applicable for the areas like horticulture, physiology and agronomy.</span>展开更多
The allelopathic potential of aqueous and organic solvent extacts from Corrigiola telephiifolia Pour which is an aromatic and medicinal plant in mediterranean regions, was investigated under laboratory conditions on t...The allelopathic potential of aqueous and organic solvent extacts from Corrigiola telephiifolia Pour which is an aromatic and medicinal plant in mediterranean regions, was investigated under laboratory conditions on two plant species: Raphanus sativus and Triticum aestivum. The aqueous extract of Corrigiola telephiifolia roots had an important inhibitory effect on the seed germination of the two tested plant species. The dichloromethane and the methanol extracts significantly reduced the growth of radish roots up to 84.44% and 68.85% respectively. The butanol, the dichloromethane and the ethyl acetate extracts had a high inhibitory effect on seed germination and roots growth of wheat. The presence of saponins in butanol extracts and tanins in dichlorometane and ethyl acetate extracts may be responsible of these allelopathic activities. These results suggest that Corrigiola telephiifolia Pour have allelopathic effects and contains potent allelochemicals which should be used for weeds management.展开更多
On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60...On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)were analyzed.The results showed that maize germination rate,germination vigor and growth index decreased with the increase of Pb concentration.The root length,surface area of maize increased by 0.21%-81.58%,8.99%-73.43%,1.50%-77.37%,respectively,under 20-500 mg/L Pb concentration.However,these parameters under 1000-3000 mg/L Pb concentration decreased by 37.86%-553.54%,44.99%-766.16%,55.99%-92.81%,respectively,and these lowest value appeared in 3000 mg/L Pb treatment.The root volume of maize increased by 4.57%-89.25%in 20-80 mg/L Pb concentration,and it decreased with the increase of Pb concentration when the Pb concentration was higher than 80 mg/L and decreased by 94.13%in 3000 mg/L Pb.The root surface area and length of 0.50-1.00 diameter class were higher than those of other diameter classes,and these value of maize under 500 mg/L Pb were higher than those of other concentrations.The length and perimeter of maize leaves with the highest value of 220.36 and 962.68 mm,respectively appeared in 60 mg/L Pb treatment.The leaf width and area of maize with the highest value of 15.68 mm and 2448.31 mm^(2),respectively,appeared in 40 mg/L Pb treatment,which indicated that the leaf traits of maize were promoted by low concentration Pb and inhibited by high concentration Pb.展开更多
Without grammar,very little can be conveyed;without vocabulary,nothing can be conveyed.Word formation is of great significance in vocabulary teaching and learning,and having a good command of root,stem,and base can pr...Without grammar,very little can be conveyed;without vocabulary,nothing can be conveyed.Word formation is of great significance in vocabulary teaching and learning,and having a good command of root,stem,and base can promote teaching and learning efficiently and effectively.This paper mainly aims to make a brief review of root,stem and base,and their application in textbooks.展开更多
文摘[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effects were observed 5, 10, 15 and 30 d after drug application, with the remained weeds surveyed 15 and 30 d after drug application. [Result] The test showed pyrazosulfuron-ethyl·quinclorac 50%WP was safe to rice as treatment agent of stem and leaf, and rice yield increased dramatical y, with the growth rate in 2.1%-49.3%. After the drug application, the prevention effects on Echinochloa crusgal i, Ludwimlia prostrata, Monochoria vamli-nalis, and Zong grass were 92.2%, 96.6%, 93.5%, and 94.8%, and the effects on fresh weight were 94.8%, 97.1%, 93.3% and 94.9%, respectively. [Conclusion] Pyra-zosulfuron-ethyl·quinclorac 50% WP can be taken as treatment agents of stem and leaf of dry direct seeded rice.
基金supported by the National Key R&D Program of China(2018YFD1000900)the National Natural Science Foundation of China(31571605,31801276)+5 种基金the Major Basic Research Project of Natural Science Foundation of Shandong Province,China(2018GHZ007)the Major Scientific and Technological Innovation Project in Shandong Province,China(2018YFJH0601)the Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2018D04,CXGC2016B03-1)the Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2018E13,CXGC2016B10,CXGC2018F6)the Major Agricultural Application Technology Innovation Project in Shandong Province,China(201706)the earmarked fund for China Agriculture Research System(CARS-13)。
文摘Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing method does not facilitate mechanization during sowing.The objective of this study was to determine if single-seed sowing at a proper seeding rate yielded better than traditional double-seed sowing pattern and the differences of physiological metabolism of roots.A field experiment was conducted in two consecutive years to compare pod yields of single-seed sowing at 180000(S180),225000(S225),and 270000 seeds ha^-1(S270)with that of double-seed sowing at 270000 seeds ha^-1(D270)using a completely randomized block design with four replications.And the root bleeding sap rate,nutrient content,and the main hormone contents in root bleeding sap were also comparatively investigated.Although the pod yields of single-seed sowing at the three densities were higher than that of traditional double-seed sowing(D270),S225 yielded better than the other two single-seed sowing treatments(S180 and S270).The increased pod yield in single-seed sowing at 225000 seeds ha^-1 was mainly due to the higher pod dry weight per plant and harvest index.The improved pod dry weight and shoot growth had closely relationship with the enhanced root physiological traits such as the increased root bleeding sap rate,content of free amino acids,soluble sugars,K^+,Mg^2+,Zn^2+,and Ca^2+of the individual plant root.The improved activity of root reductive,nitrate reductase(NR)and ATPase and higher zeatin and zeatin riboside(Z+ZR)content of root bleeding sap were alsocrucial to the pod and shoot growth of peanut.Single-seed sowing at a moderate seeding rate(S225)is a potential practice to increase pod yield and to save seed cost.
基金supported by the National Natural Science Foundation of China(Grant No.31371571)the National High Technology Research and Development Program of China(863 Program)(Grant No.2014AA10A605)the Fundamental Research Funds for the Central Universities(Grant No.2662017JC001)
文摘Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice (DSR) has been considered as a replacement for traditional transplanted flooded rice (TFR). However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.
基金the Guangdong Basic and Applied Basic Research Foundation(Grant No.2020B1515020034)the National Postdoctoral Program for Innovative Talents(Grant No.BX201700083)+3 种基金the Commonweal Project(Grant No.201203059)the Key Research and Development Program of Guangdong(Grant No.2019B020221003)the National Key Research and Development Program of China(Grant No.2018YFD0100800)as well as the China Agriculture Research System(Grant No.CARS-01-41).
文摘Mechanical hill wet-seeded rice machine is beneficial for establishing and growing uniform rows of seedlings.However,there is limited knowledge regarding the effects of the establishment of furrows on growth,lodging and yield,and their relationships with root traits.In this study,field experiments were conducted during 2012 and 2013 using two super rice varieties(hybrid rice Peizataifeng and inbred rice Yuxiangyouzhan)under three furrow establishment treatments(T1,both water and seed furrows were established by the machine;T2,only seed furrows were established by the machine;and T3,neither water nor seed furrows were established by the machine).Lodging index,lodging-related traits,grain yield,above-ground dry weight and root traits were measured.The results showed that the lodging index was significantly affected by the treatments with furrows(T1 and T2).The strongest lodging resistance was detected in the mechanical hill wet-seeded rice with furrow treatment(T1)in both 2012 and 2013.Lodging resistance was strongly related to the breaking resistance.No significant difference was found in grain yield or dry weight of the mechanical hill wet-seeded rice.Therefore,the mechanical hill wet-seeded rice with furrow treatment increased rice lodging resistance,which was related to root traits.
基金the National institute for Global Environmental Change (DOENIGEC), Program for Ecosystem Research (DOE-PER Grant D E- FG O Z-9
文摘An open-top chamber experiment was conducted at the University of Michigan Biological Station near Pellston, Michigan, USA, to study the effects of soil fertility and CO2 on leaf, stem and root dark respiration (Rd) of Populus tremuloides. Overall, area-based day-time leaf Rd (Rda) was significantly greater at elevated than at ambient CO2 in high-fertility soil, but not in low-fertility soil. Mass-based leaf Rd (Rdm) was overall greater for high- than for low-fertility soil grown trees at elected, but not at ambient CO2. Nighttime leaf Rd. and Rdm were unthected by soil fertility or CO2, nor was stem Rda, which ranged from 1.0 to 1.4 μmol m-2 s-1 in the spring and 3.5 to 4.5 μmol m-2 s-1 in the summer. Root Rda. was significantly higher in high- than in low-fertility soil, but was unaffected by CO2. Since biomass production of P. tremuloides will be significantly greater at elevated CO2 while specific Rd will either increase or remain unchanged, we predict that carbon loss to the atmosphere through respiration from this ecologically important species would increase at higher CO2. Soil fertility would also interact with elevated CO2 in affecting the carbon flow in the plant-soil-air system.
基金supported by the National Natural Science Foundation of China,No.81601057(to JTY)
文摘Nerve grafting has always been necessary when the contralateral C7 nerve root is transferred to treat brachial plexus injury. Acellular nerve allograft is a promising alternative for the treatment of nerve defects, and results were improved by grafts laden with differentiated adipose stem cells. However, use of these tissue-engineered nerve grafts has not been reported for the treatment of brachial plexus injury. The aim of the present study was to evaluate the outcome of acellular nerve allografts seeded with differentiated adipose stem cells to improve nerve regeneration in a rat model in which the contralateral C7 nerve was transferred to repair an upper brachial plexus injury. Differentiated adipose stem cells were obtained from Sprague-Dawley rats and transdifferentiated into a Schwann cell-like phenotype. Acellular nerve allografts were prepared from 15-mm bilateral sections of rat sciatic nerves. Rats were randomly divided into three groups: acellular nerve allograft, acellular nerve allograft + differentiated adipose stem cells, and autograft. The upper brachial plexus injury model was established by traction applied away from the intervertebral foramen with micro-hemostat forceps. Acellular nerve allografts with or without seeded cells were used to bridge the gap between the contralateral C7 nerve root and C5–6 nerve. Histological staining, electrophysiology, and neurological function tests were used to evaluate the effect of nerve repair 16 weeks after surgery. Results showed that the onset of discernible functional recovery occurred earlier in the autograft group first, followed by the acellular nerve allograft + differentiated adipose stem cells group, and then the acellular nerve allograft group;moreover, there was a significant difference between autograft and acellular nerve allograft groups. Compared with the acellular nerve allograft group, compound muscle action potential, motor conduction velocity, positivity for neurofilament and S100, diameter of regenerating axons, myelin sheath thickness, and density of myelinated fibers were remarkably increased in autograft and acellular nerve allograft + differentiated adipose stem cells groups. These findings confirm that acellular nerve allografts seeded with differentiated adipose stem cells effectively promoted nerve repair after brachial plexus injuries, and the effect was better than that of acellular nerve repair alone. This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Sun Yat-sen University of China(approval No. 2016-150) in June 2016.
基金Supported by Funding Project of Hebei Provincial Department of Education(ZD20131022,ZD2019057)First Batch Financial Support for Hebei Provincial Hundred Outstanding Innovative Talents in China.
文摘The root of Scutellaria baicalensis Georgi is traditionally used as medicine,and it has been confirmed that S.baicalensis Georgi has flavonoid chemical constituents,pharmacological activity and cosmetic efficacy.With the extensive application of S.baicalensis Georgi roots,the resource of S.baicalensis Georgi has been increasingly short.The above-ground part of stems and leaves of S.baicalensis Georgi has also been gradually recognized and developed.Studies have found that the chemical constituents from stems and leaves of S.baicalensis Georgi are also a group of flavonoids with a lot of pharmacological activity and have a great application value.Based on this,the present review will be reported on the chemical constituents and application of the roots,stems and leaves of S.baicalensis Georgi.
文摘The present study, conducted during 2016 and 2017 seasons, aimed to investigate the effect of IBA on rooting of Piper betle L. stem cuttings (softwood and semi-hardwood). The experiment was undertaken in misting house field 2 UPM using the sand media to determine the adventitious roots initiation and development using the histological method. The cuttings were treated with different IBA concentrations (0, 500, 1000, 1500 and 2000 mg/L). The nodes explants were used in the development of a protocol for in vitro propagation of P. betle L., with different concentrations of Clorox with different times of immersion (20% Clorox 10 minutes, 30% Clorox 10 minutes, 20% Clorox 20 minutes, and 30% 20 minutes). In multiplication of the plantlets, Murashige and Skoog (MS) medium with different concentrations of BAP (0, 0.5, 1.0, 2.0 mg/L) were used to investigate the rooting of the explants. The results indicated that the types of the cuttings were different in the rooting capacity and the length of the roots. Moreover, it was found that in comparison with the control treatment, by a rise in the concentrations of the IBA, there was a significant upsurge in the rooting percentage, the root diameter, and the number of the roots. The results indicated that the types of cutting with 1000, 1500 and 2000 mg/L IBA perform better in the root percentage (100%) in the semi hardwood cuttings. The best results, however, were 2000 mg/L IBA in the semi hardwood cuttings, with the number of the roots to be 35.05, and the fresh weight of the roots to be 3.94 g, the dry weight of the roots to be 0.33 g, the length of the roots to be 391.88 cm, the roots diameter to be 1.21 mm, the surface area of the roots to be 121.83 cm2, and the root volume to be 2.99 cm3. Nonetheless, the optimal concentration of Clorox with the time immersion was 20% with the 20-minute immersion time, which produced a shoot induction percentage of 30% dead explants and a mean number of 70.00 shoots per explant and the optimal concentration of benzylaminopurine (BAP) at 1.0 mg/L. It is of note that a shoot induction percentage of 22.29% and a mean number of 4.1% number of auxiliary bud per treatment. P. betle shoots in MS medium without PGR MS (0.0) yielded a good rooting.
基金grants from the National Natural Science Foundation of China (51222905, 51321001, 51439006)the National High-Tech R&D Program of China (863 Program, 2011AA100505)+1 种基金the Ministry of Water Resources of China (201201003)the Program for New Century Excellent Talents in University, Ministry of Education, China (NCET11-0479)
文摘Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bottleneck for its long-term sustainability. Investigating the transpiration of seed-maize plants will offer valuable information for suitable planting and irrigation strategies in this arid area. In this study, stem flow was measured using a heat balance method under alternate furrow irrigation and double-row ridge planting. Meteorological factors, soil water content (e), soil temperature (Ts) and leaf area (LA) were also monitored during 2012 and 2013. The diurnal stem flow and seasonal dynamics of maize plants in the zones of south side female parent (SFP), north side female parent (NFP) and male parent (MP) were investigated. The order of stem flow rate was: SFP〉MP〉NFP. The relationships between stem flow and influential factors during three growth stages at different time scales were analyzed. On an hourly scale, solar radiation (Rs) was the main driving factor of stem flow. The influence of air temperature (Ta) during the maturity stage was significantly higher than in other periods. On a daily scale, Rs was the main driving factor of stem flow during the heading stage. During the filling growth stage, the main driving factor of NFP and MP stem flow was RH and Ts, respectively. However, during the maturity stage, the environ- mental factors had no significant influence on seed-maize stem flow. For different seed-maize plants, the main influential factors were different in each of the three growing seasons. Therefore, we identified them to accurately model the FP and MP stem flow and applied precision irrigation under alternate partial root-zone furrow irrigation to analyze major factors affecting stem flow in different scales.
基金supported by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health (No. R01NS102360)。
文摘It was hypothesized that mesenchymal stem cells(MSCs) could provide necessary trophic factors when seeded onto the surfaces of commonly used nerve graft substitutes. We aimed to determine the gene expression of MSCs when influenced by Avance■ Nerve Grafts or Neura Gen■ Nerve Guides. Human adipose-derived MSCs were cultured and dynamically seeded onto 30 Avance■ Nerve Grafts and 30 Neura Gen■ Nerve Guides for 12 hours. At six time points after seeding, quantitative polymerase chain reaction analyses were performed for five samples per group. Neurotrophic [nerve growth factor(NGF), glial cell line-derived neurotrophic factor(GDNF), pleiotrophin(PTN), growth associated protein 43(GAP43) and brain-derived neurotrophic factor(BDNF)], myelination [peripheral myelin protein 22(PMP22) and myelin protein zero(MPZ)], angiogenic [platelet endothelial cell adhesion molecule 1(PECAM1/CD31) and vascular endothelial cell growth factor alpha(VEGFA)], extracellular matrix(ECM) [collagen type alpha I(COL1A1), collagen type alpha III(COL3A1), Fibulin 1(FBLN1) and laminin subunit beta 2(LAMB2)] and cell surface marker cluster of differentiation 96(CD96) gene expression was quantified. Unseeded Avance■ Nerve Grafts and Neura Gen■ Nerve Guides were used to evaluate the baseline gene expression, and unseeded MSCs provided the baseline gene expression of MSCs. The interaction of MSCs with the Avance■ Nerve Grafts led to a short-term upregulation of neurotrophic(NGF, GDNF and BDNF), myelination(PMP22 and MPZ) and angiogenic genes(CD31 and VEGFA) and a long-term upregulation of BDNF, VEGFA and COL1A1. The interaction between MSCs and the Neura Gen■ Nerve Guide led to short term upregulation of neurotrophic(NGF, GDNF and BDNF) myelination(PMP22 and MPZ), angiogenic(CD31 and VEGFA), ECM(COL1A1) and cell surface(CD96) genes and long-term upregulation of neurotrophic(GDNF and BDNF), angiogenic(CD31 and VEGFA), ECM genes(COL1A1, COL3A1, and FBLN1) and cell surface(CD96) genes. Analysis demonstrated MSCs seeded onto Neura Gen■ Nerve Guides expressed significantly higher levels of neurotrophic(PTN), angiogenic(VEGFA) and ECM(COL3A1, FBLN1) genes in the long term period compared to MSCs seeded onto Avance■ Nerve Grafts. Overall, the interaction between human MSCs and both nerve graft substitutes resulted in a significant upregulation of the expression of numerous genes important for nerve regeneration over time. The in vitro interaction of MSCs with the Neura Gen■ Nerve Guide was more pronounced, particularly in the long term period(> 14 days after seeding). These results suggest that MSC-seeding has potential to be applied in a clinical setting, which needs to be confirmed in future in vitro and in vivo research.
基金supported by Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Personnel of China,2011,Ren 1144
文摘The use of iodine-125 (L251) in cancer treatment has been shown to relieve patients' pain. Consid- ering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we assumed that 125I could be implanted into rat dorsal root ganglia to provide relief for neuropathic pain. 125I seeds with different radioactivity (0, 14.8, 29.6 MBq) were im- planted separately through L4-5 and L5-6 intervertebral foramen into the vicinity of the L5 dorsal root ganglion, von Frey hair results demonstrated the mechanical pain threshold was elevated after implanting 125I seeds from the high radioactivity group. Transmission electron microscopy revealed that nuclear membrane shrinkage, nucleolar margination, widespread mitochondrial swelling, partial vacuolization, lysosome increase, and partial endoplasmic reticulum dilation were visible at 1,440 hours in the low radioactivity group and at 336 hours in the high radio- activity group. Abundant nuclear membrane shrinkage, partial fuzzy nuclear membrane and endoplasmic reticulum necrosis were observed at 1,440 hours in the high radioactivity group. No significant difference in combined behavioral scores was detected between preoperation and postoperation in the low and high radioactivity groups. These results suggested that the mechan- ical pain threshold was elevated after implanting 125I seeds without influencing motor functions of the hind limb, although cell injury was present.
基金supported by the Young Scientist Fund of Jilin Provincial Science and Technology Department,No.20090183
文摘An experimental model of brachial plexus root avulsion injury of cervical dorsal C5-6 was established in adult and neonatal rats.Real-time PCR showed that the levels of brain-derived neurotrophic factor,nerve growth factor and neurotrophin-3 in adult rats increased rapidly 1 day after brachial plexus root avulsion injury,and then gradually decreased to normal levels by 21 days.In neonatal rats,levels of the three neurotrophic factors were decreased on the first day after injury,and then gradually increased from the seventh day and remained at high levels for an extended period of time.We observed that greater neural plasticity contributed to better functional recovery in neonatal rats after brachial plexus root avulsion injury compared with adult rats.Moreover, immunohistochemical staining showed that the number of bromodeoxyuridine/nestin-positive cells increased significantly in the spinal cords of the adult rats compared with neonatal rats after brachial plexus root avulsion injury.In addition,the number of bromodeoxyuridine/glial fibrillary acidic protein-positive cells in adult rats was significantly higher than in neonatal rats 14 and 35 days after brachial plexus injury.Bromodeoxyuridine/β-tubulin-positive cells were not found in either adult or neonatal rats.These results indicate that neural stem cells differentiate mainly into astrocytes after brachial plexus root avulsion injury.Furthermore,the degree of neural stem cell differentiation in neonatal rats was lower than in adult rats.
基金Supported by the Cooperative Project Between the People's Republic of China and the Republic of Korea
文摘[Objectives] This study was conducted to investigate the effects of different treatments on rooting and germination of Paeonia rockii T. Hong et J.J.Li seeds. [Methods] Different stratification time and temperatures and different GA_3 concentrations and treatment time were set to screen the optimum treatment method for promoting seed rooting and germination. [Results] The rooting rate was the highest when the seeds were subjected to 30 d of stratification treatment in an incubator at 25℃, and treated with 300 mg/L GA_3 for 24 h. Soaking the seeds with 300 mg/L GA_3 for 24 h combined with 30 d of stratification treatment was most beneficial to germination, and the germination rate was over 90%. [Conclusions] This study provides technical guidance and basic information for the rooting and germination of P. rockii seeds.
文摘A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.
文摘Tomatoes are one of the main vegetables in the food industry that are consumed fresh and processed. A multi-element microanalysis was performed with the use of scanning electron microscopy (SEM) in conjunction with energy dispersion spectroscopy (EDS), to see changes in nutrient concentration in roots and leaves, as well as fresh and dry biomass in tomato seedlings. Exposed in nutrient solution (NS) with different levels of Ca (control, 25, 50 and 100 mM). The root was put in also<span lang="EN-US" style="font-size:10pt;font-family:;" "=""> </span><span lang="EN-US" style="font-size:10pt;font-family:;" "="">to H<sub>2</sub>O<sub>2</sub> for 8 hours to observe the changes that occurred. It was observed that NS with 100 mM Ca in fresh stem biomass and fresh leaf biomass increased by 25% and 38% compared to the control. It was observed that the NS with 100 and 50 mM of Ca, the content of Ca and Cl in foliar tissue increased by 34.50% and 13.15% compared to the control. Treatment with H<sub>2</sub>O<sub>2</sub> and with 25 and 100 mM of Ca at NS increased the height of the seedling and fresh leaf bio-mass by 19.75% and 60.80% compared to the control. The treatment with H<sub>2</sub>O<sub>2</sub> and with the different levels of Ca in the NS increased the content of C, P, K, Ca and Cl in the leaf tissue. Only S was significant for the control. Treatment with H<sub>2</sub>O<sub>2</sub> and 100 mM Ca in the NS increased Ca and Mg by 83.48% and 40.47% for the root compared to the control. The K and Cl in the root was higher in the control treatment by 47.61% and 55% respect to the highest level of Ca.</span><span lang="EN-US" style="font-size:10pt;font-family:;" "=""> </span><span lang="EN-US" style="font-size:10pt;font-family:;" "="">It is concluded that multielemental microanalysis is a powerful, non-destructive, fast and accurate tool for the determination of plant nutrients. Also, it is applicable for the areas like horticulture, physiology and agronomy.</span>
文摘The allelopathic potential of aqueous and organic solvent extacts from Corrigiola telephiifolia Pour which is an aromatic and medicinal plant in mediterranean regions, was investigated under laboratory conditions on two plant species: Raphanus sativus and Triticum aestivum. The aqueous extract of Corrigiola telephiifolia roots had an important inhibitory effect on the seed germination of the two tested plant species. The dichloromethane and the methanol extracts significantly reduced the growth of radish roots up to 84.44% and 68.85% respectively. The butanol, the dichloromethane and the ethyl acetate extracts had a high inhibitory effect on seed germination and roots growth of wheat. The presence of saponins in butanol extracts and tanins in dichlorometane and ethyl acetate extracts may be responsible of these allelopathic activities. These results suggest that Corrigiola telephiifolia Pour have allelopathic effects and contains potent allelochemicals which should be used for weeds management.
基金Basic Research in Yunnan Local Colleges and Universities(2017FH001-026,2018FH001-004)the National Natural Science Foundation of China(42167009,31300349)International Joint Innovation Team for Yunnan Plateau Lakes and Great Lakes of North America which is sponsored by Yunnan Provincial Education Department(to XC),and Scientific and Technological Innovation team Project of Agricultural Resources Utilization of Kunming University.
文摘On base of the content of Pb in the soil under different land use patterns in Lanping Lead-zinc mining area,Yunnan in southwest China,the root morphology and leaf traits of maize in different concentration Pb(20,40,60,80,100,150,200,500,1000,2000,3000 mg/L)were analyzed.The results showed that maize germination rate,germination vigor and growth index decreased with the increase of Pb concentration.The root length,surface area of maize increased by 0.21%-81.58%,8.99%-73.43%,1.50%-77.37%,respectively,under 20-500 mg/L Pb concentration.However,these parameters under 1000-3000 mg/L Pb concentration decreased by 37.86%-553.54%,44.99%-766.16%,55.99%-92.81%,respectively,and these lowest value appeared in 3000 mg/L Pb treatment.The root volume of maize increased by 4.57%-89.25%in 20-80 mg/L Pb concentration,and it decreased with the increase of Pb concentration when the Pb concentration was higher than 80 mg/L and decreased by 94.13%in 3000 mg/L Pb.The root surface area and length of 0.50-1.00 diameter class were higher than those of other diameter classes,and these value of maize under 500 mg/L Pb were higher than those of other concentrations.The length and perimeter of maize leaves with the highest value of 220.36 and 962.68 mm,respectively appeared in 60 mg/L Pb treatment.The leaf width and area of maize with the highest value of 15.68 mm and 2448.31 mm^(2),respectively,appeared in 40 mg/L Pb treatment,which indicated that the leaf traits of maize were promoted by low concentration Pb and inhibited by high concentration Pb.
文摘Without grammar,very little can be conveyed;without vocabulary,nothing can be conveyed.Word formation is of great significance in vocabulary teaching and learning,and having a good command of root,stem,and base can promote teaching and learning efficiently and effectively.This paper mainly aims to make a brief review of root,stem and base,and their application in textbooks.