Dissertation > Excellent graduate degree dissertation topics show

Effects of Na2CO3 Stress on Growth and Photosynthetic Characteristics of Vicia Faba L.

Author: LiuXia
Tutor: WangBaoShan
School: Shandong Normal University
Course: Botany
Keywords: Na2CO3 stress Vicia faba L. growth of seedlings photosythesis characteristics pH
CLC: Q945.78
Type: Master's thesis
Year: 2008
Downloads: 177
Quote: 4
Read: Download Dissertation

Abstract


Photosynthesis is always one hotspot in scientific researches. But few studies are carried out on the plant photosynthesis under alkaline salt stress and there are still many basic problems unresolved. Even fewer studies focus on the photosynthesis of halophytes. In this study we try to clarify the effect of alkaline salt stress on photosynthesis of Vicia faba L. and to further explore the detrimental mechanism of alkaline salt stress. Four groups of young seedlings of Vicia faba L. were treated with 0, 5, 10, 15 and 25 mmol/L Na2CO3 for 6 days, respectively. The photosynthetic rate, chlorophyll fluorescence parameter and other physiological indices were measured. The main results are shown as follows:1. Effect of Na2CO3 on growth of Vicia faba L.Under the treatment with 15 mmol/L Na2CO3, both fresh weight and dry weight of Vicia faba L. were higher than those of the control（P<0.05）.But fresh weight of Vicia faba L. decreased significantly（P<0.05）under the treatment with 25 mmol/L Na2CO3. It indicates that low concentration of Na2CO3 （5mmol/L） promotes the growth of Vicia faba L. and high concentration of Na2CO3 inhibits its growth.2. Effect of Na2CO3 on photosynthetic gas exchange parameters of Vicia faba L.Pn, Gs and Ci declined in a range of 5-15mmol/L Na2CO3, while Ls increased, which proves that the stomata is the main limited factor. Under the high concentration of 25mmol/L Na2CO3, though Pn, Gs and Ls drop significantly, Ci rises. It proves that the stomatal limitation of photosynthesis decreases, but the non-stomatal limitation factor increases.3. Effect of Na2CO3 on chlorophyll fluorescence parameters of Vicia faba L.Fv/Fm decreased gradually with the increase of salt concentration and significant difference （P<0.05）could be observed between plants treated with 25mmol/L Na2CO3 and the control. It indicates that photochemical efficiency of PSⅡhas been inhibited by high concentration of Na2CO3.φPSⅡ, which reflects the actual quantum yield of electron transport in PSⅡ,was higher in plants treated with 10mmol/L Na2CO3 than that in the control （P<0.05）, then decreased gradually with the increase of salt concentration. The value at 25mmol/L Na2CO3 treatment was the lowest and significant difference （P<0.05） found compared with the control. It indicates that the actual quantum yield and the electron transport rate of PSⅡhave been promoted under lower concentration of Na2CO3 but suppressed under higher concentration.4. Effect of Na2CO3 on Chlorophyll content of Vicia faba L.Content of chlorophyll a,b, and a+b slightly decreased under the treatment with 5 mmol/L Na2CO3 and then increased with the increase of Na2CO3 concentration.It is possible that salinity has promoted the formation of chlorophyll,and/or the inhibited growth of leaf area under salt stress has caused relative increase of chlorophyll content.Chlorophyll a/b content increased significantly with the increase of salt concentration up to 15mmol/L and then decreased at 25 mmol/L,but all the values under salt stress were higher than those of the control.This indicates that thylakoids still had higher stack extent possibly under the salt treatment.5. Effect of Na2CO3 on soluble sugar content of Vicia faba L.Soluble sugar content of the leaves increased with the increase of salt concentration and significant difference （P<0.05） was observed between the plants treated with 25mmol/L Na2CO3 and control. It indicates that feedback restriction caused by soluble sugar accumulation is probably one of the reasons why photosynthesis of Vicia faba L. decreased.6. Effect of Na2CO3 on plasma membrane of Vicia faba L.MDA content is used as an indicator of oxidative damage degree in environmental stresses. At low concentration of Na2CO3 [5 mmol/L], leaf MDA did not show distinct increase. Under the condition of high Na2CO3 concentration [15, 25 mmol/L Na2CO3], leaf MDA showed distinguished increase（P<0.05）.While the relative electric conductivity of the plasma membrane showed the same trend with that of MDA content. Therefore, plasma membrane was not significantly affected by low concentration of Na2CO3. However, high concentration of the Na2CO3 caused distinct damage to the cell membrane of Vicia faba L. leading to accumulation of MDA.In conclusion, low concentration of Na2CO3 [5 mmol/L] promotes the growth of Vicia faba L. However, under high concentration of Na2CO3, both growth and photosynthesis are inhibited obviously. On the one hand, the reduced photosynthetic rate results from stomatal limitation factors and non-stomatal limitation factors, such as the block of electron transport, the down-regulation of PSⅡreaction center activity and the feedback restriction due to soluble sugar accumulation. On the other hand, the reduction of the RuBPCase activity maybe also lead to photosynthetic rate reduction under condition of Na2CO3. In addition, Fv/Fm only decreased by 9.3% compared with the control. It suggests that Na2CO3 stress did not obviously influence the PSⅡactivity.

Related Dissertations

  1. Research on Predictive Control and Simulation of pH Value Based on the Confection Process of Sodium Nitrate,TP273
  2. Study on Preparation and Properties of Protein Isolates from Tilapia,TS254.4
  3. Bovine serum albumin and protamine from NOCC / alginate hydrogels release : the isoelectric point of two different biological molecules controlled trial,R943
  4. Study on Performances of Hydrogen Sulfide Removed in Bio-trickling Filter with Concentrations of Ammonia Existence,X511
  5. Research on the Five-Axis CNC Interpolation Technology Based on PH Spline,TG659
  6. Study on Process Analysis and Oil Absorptive Properties of Kaolin Modified by Acid and Alkali,TD985
  7. Mechanism of Facilitation Phosphorus Uptake in Chickpea/maize and Rape/maize Intercropping,S565.4;S513
  8. Research of IMC Algorithm Applied in pH Value Control System for Flue Gas Resulfurization of Coal-Fired Boiler,TP273
  9. The Research about the Main Factors Which Effect on the Eluviation of Heavy Metals in the Soil,X53
  10. Design and Implementation of the Real-time Motion Controller ASIC for Pythagorean Hodograph Curve,TG659
  11. Effects of Neutral Detergent Fiber Composition of Ryegrass and Particle Size on Eating Behavior, Ruminal Fermentation and Rumen Degradation Kinetics of Goats,S827.5
  12. Hyperacute cerebral infarction 1.5T magnetic resonance imaging chemical exchange saturation transfer,R445.2
  13. Screening and Expression Analysis of Genes Response to Aluminum Stress in Leaves of Yunnan Faba Bean,X173
  14. Preparation of Organic-Inorganic Functional Hybrid Microcapsules from Pickering Emulsion Polymerization,TB332
  15. The Silica Reaction Kettle Process Control System of Research and Design Based on PLC,TP273
  16. Research on Correlation between Esophagus PH and Blood Serum Gastrointestinal Hormone Changes in Diabetes,R571
  17. A Novel pH-sensitive Hydrogel Based on Dual Crosslinked Alginate/N-α-glutaric Acid Chitosan for Oral Delivery of Protein,R94
  18. Construction of Autofluorescent Chitosan Microspheres for Gastric Target and Mechanism of Autofluorescence,R94
  19. Status and Management Measures of Soil Fertilities of Cultivated Land in Zhejiang Province, China,S158.5
  20. Based difluoroborane structure of the new fluorescent / chemiluminescent probe design synthesis and biological applications,O657.3
  21. Studies on the Synthesis and Properties of Acrylamide Polyelectrolytes,O633.22

CLC: > Biological Sciences > Botany > Plant Physiology > Hip forced Physiology
© 2012 www.DissertationTopic.Net  Mobile