Effect Of Some Treatments On Salt Tolerence Of Plant:

M. G. M. Rifaat

- 190 -5- SUMMARYThe current study was carried out to investigate theeffect of seed pretreatments with certain soaking solutionson salt tolerance of wheat plants.Tested soil samples were taken out from the fields ofpermenant experiments in the form of Agricultural ResearchCenter- Giza Governorate. Sea water sample was collectedfrom El- Madia No.6. Al- Esmailia Governorate and wasdiluted with tap water having a final concentration of about(5242) ppm for using in irrigation.Six groups of soaking solutions are used. The firstgroup involved four growth regulators. i.e. Indole -3-acetic acid (IAA). Indole -3- butyric acid (IBA). alpha-Napthalene acetic acid (NAA) and Gibberellic acid (GA). Thesecond group involved three amino acids. namely, Proline.Glutamic and Aspartic acids. The third group included thechloride solutions of both sodium and magnesium while thefourth group contained two solutions of potassium in eitherform KH2P04 or KNO~. The fifth group involved sulphatesolutions of each Zn. Mn. Cu or Fe. Distilled water was thesixth group of soaking solutions.To fulfill the purpose of this study. two pot experimentswere conducted under the greenhouse conditions usingwheat seeds (Sakha- 8 varities).191 -1- A preliminary experimentDifferent concentrations of the studied soaking solutionsas well as different periods of soaking were investigatedto find out the most suitable concentrations of eachof the soaking solution along with the best period ofsoaking.The studied concentrations of the growth regulatorswere 100, 200, 300 and 400 ppm while the amino acids wereused in four concentrations, namely,S, 10, 15 and 20 ppm.Concentrations of the chloride solutions were 1 ~, 2 ~, 3 ~and 4~ ’I. whereas,500, 1000, 2000potassium solutions concentrations wereand 3000 ppm. Soaking of the previouslymentioned concentrations of the different soaking solutionscovered a period of either 12 or 24 hours. Concentrations ofsulpllate solutions of the micronutrients were 0.02 ’I.,0.03 ’I.,0.04 ’I. and 0.05 ’I.. Soaking periods herein extended up toeither 6 or 12 hours.Ano the r- set of wheat seeds were soaked in the distilledwater for either of 6, 12 or 24 hours along with untreatedseeds (which irrigated with tap water) were also tried.Each pot fertilized with N, P and K at rates of 75.5kg, 100 kg and 50 kg/ fed. in the form ammonium sulphate(20.5 ’I.N), superphosphate (15.5 ~ P;aO.) and potassium sulphatE!(48 ’I.K;aO), respectively. Each treatment was replicatedthree times.- 192 -Irrigation of the pots was conducted using a dilutedsea water and moisture content was maintained at 70 ~ of thefield capacity.lected, driedrecorded.After 45 days from sowing, plants were colat70°C and the dry weight per pot was2- Biological main experiment:The most suitable concentration of soaking solutionsalong with the best period of soaking were choosen from thepreliminary experiment. A complete randomized design wasused for this experiment. The N. P and K fertilization wasconducted at the same rates followed in the preliminaryexperiment. The moisture content of each pot was maintainedat the field capacity using the same diluted sea water.During the growing season of wheat plants, three randoreelyselected pots were taken from each treatment fourtimes, i.e. at IS, 45. 75 and 140 days after sowing.Results of the conducted experiments could be summarizedin the following: -A- The preliminary experiment1- The best treatments which gave the most favourableres.ponse for growth by wheat plants were seed soaking for 12hour-s interval in solutions of 200 ppm (IAA). 300 ppm (IBA).100 ppm (NAA). 300 ppm (GA). 5 ppm for all amino acids. 3 ’t._~_._------------------- -_.---------- 193 -NaCl. 2 ~ MgCla• 1000 ppm (KHaPO.•). 500 ppm (KNO~) and 0.03% for each of micronutrients sulphate solutions.2- Soaking seeds in distilled water resulted in noresponse for plant growth. however. investigated period was6. 12 and/or 24 hours as compared with untreated seeds.B- Biological main experiment:1- Plant height was significantly affected by the varioussoaking solutions. The most favourable treatments wereNAA. NaC!. KNO~. ZnSO.•.and/or Aspartic acid.2- Number of tillers were significantly affected bythe varIOUS soaking solutions and the most response whenseeds were soaked in solutions of NAA. MgCla• KN03• MnSO.•.and/or Proline.3- Dry matter weights of wheat plants were significantlyaffected by the various soaking solutions duringvarious growth periods and the most favourable media after140 days (straw yield) was CuSO.•.•Proline. KNOs• NaCI and/orNAA.4- Dry matter weight of wheat roots after 140 days ofsowing were significantly affected by the various soakingsolutions. The corresponding average values could be arrangedaccording the various soaking solutions:NAA > Proline> CuSO.•.> KNOs > Aspartic > Glutamic > MnSO.•.>KHaPO....--- lAA === ZnSO.•-•-.- IBA > NaC! === PeSO...> MgCla=== GA > Distilled water.- 194 -5- Root length was significantly affected by thevarious soaking solutions at harvesting (140 days) and couldbe arranged descendingly in the following order:NAA > NaCI > KN03 > GA === MgCl2 > Proline> IBA > KH2P04 >Aspe rt ic --- MnS04 ==::: CUUS04 ::::::= ZnS04 > IAA > FeS04 >Glutamic> Distilled water.6- Number of spikes of wheat plants at harvesting weremarkedly influenced by the various soaking solutions andcould be arranged in the descending order :CUS04 === Proline> MnS04 > FeS04 > Aspartic === IAA > IBA--- ZnS04 > KN03 === Glutamic > NAA > NaCI > MgCl2 > KH2P04> GA > Distilled water.7- Significant difference was occurred between thevarious soaking solutions on both weight of spikes andnumber of wheat grains. The most favourable response of differentsoaking solutions were IBA; Aspartic. Proline and/orFeS04 on either weight of spikes or number of wheat grains.8- Seed index (weight of 1000 grains) was significantlYaffectedby the various soaking solutions. results gavegenerally a relatively less favourable and sometimes eveninhibiting effect of developed plants under saline conditions.9- The effect of the various soaking solutions after140 days from sowing at harvesting on the nutrients uptakeof straw yield Could be summarized as follow :- 195 -A- Nitrogen was significantly influenced by IAA, NAA. GA.Proline. Glutamic acid. NaC!. KN03t ZnSO .•.a.nd CuS04•B- Phosphorus was significantly affected by lAA, lEA, NAA,NaCl, all the amino acids, potassium so!utions and allthe sulphate solutions of the micronutrients.c- Potassium was significantly influenced by Proline, KN03and ZnSO .••..D- Zinc was significantly affected by IAA. NaC!. and PeSO .•...E- All the various soaking pretreatments, except Proline wasinsignificantly effect on manganese uptake.F- All the studied soaking solutions was inf!uenced insignificantlyon copper uptake.G- Iron was significantly affected by IBA, Proline.particacid. NaCl. KN03, 2nSO .••.M•nSO .••a.nd CuSO .•...10-A- Nitrogen uptake of grain yield was significantlyaffected by IAA, IBA, Proline, Glutamic acid, Aspartic acid,NaCI, MgC13• ZnSO .••a.nd PeSO .•..h•owever. phosphorus uptake wassignificantly affected by lAA, IBA, GA, Proline. Glutamicacid. Aspartic acid. NaCI. MgCI3• KH3PO.....KN03, 2nSO .••.•MnSO .•,..CuSO .•.a.nd PeSO .•,..while. potassium uptake was affectedsignificantly by lAA, IBA. Proline. Glutamic acid. NaCI.MgCI3• 2nSO .•,..eusa .••a.nd FeSO .•...B- Protein yield in grains increased due to soakingsolutions and the highest increase was achieved upon soakingin lAA and IHA, while the lowest value was achieved uponusing distilled water for soaking •----._-~--------------------- ----.- 196 -C- Concerning the effect of the soaking solutions onthe micronutrients uptake of grain yield, IAA. GA, Aaparticacid and NaCI affected significantly zinc uptake. whilemanganese uptake was significantly with all the studiedsoaking solutions, except for KN03 treatment. whereas copperuptake was markedly affected by the various soaking solutions.Except for GA and MgCl2 solutions, seed pretreatmentsrevealed a pronounced responsed on iron uptake of grainyield.11- The mean net influxes of nitrogen and potassiumwere highest at the first period of growth (15- 45) days anddecreased markedly particularly with potassium with developmentof plant age up to (45- 75) days while at (75- 140)days a slightly decrease occurred.The mean net influx of phosphorus was increased up to75 days and decreased relatively with advancement plant age,up to 140 days after sowing due to salinity conditions.12- Considering effect of the soaking solutions on themean net influxes of nitrogen. phosphorus and potassium atthe third period of growth (75- 140) days. it could be foundthat :A- Glutamic acid was the most effective on mean valueof N- influxes while NAA was the least. The other soakingsolutions could be arranged descendingly in the follOWingorder:- 197 -IAA > GA > IBA > FeS04 > Proline > ~~03 > NaCl MgCl2 >ZnS04 > CUS04 > KH2P04 > Aspartic acid> MnS04 .B- lAA was the highest mean value of P- influxes,whereas the lowest value occurred in plants whose seeds weresoaked in N~~ treatment. The corresponding average values ofP- influxes irrespective to the other seed soaking pretreatmentscan be shown from the following descending order:FeS04 > Glutamic acid> IBA > MnS04 > Proline > ZnS04 ::=CUS04 > Aspartic acid > NaCl > GA === MgCl2 === KH2P04 >KN03.C- Aspartic acid showed the most pronounced affect onmean net K-influx whereas the lowest mean potassium flowrate existed in case of lAA seed soaking media. The othersoaking media are arranged descendingly as followsCUS04 > GA > KH2P04 > Glutamic acid === MnS04 > IBA > NAA--- NaCl === MgC12 > ZnS04 > Proline> KN03 === FeS04.13- The mean net influxes of zinc. manganese. copperand iron. generally. were highest during the first period ofwheat plants (15- 45) days and then decreased with developmentof plant age up to 75 days after sowing. However. withincreasing plant age up to 140 days resulted in decreasingthe mean net of micronutrients influx. such decrease holdsharply with both manganese and copper mean net influxes.14- With respect to the effect of various seed soakingpretreatments on the mean net of the studied micronutrientsinfluxes during the second period of growth (45- 75)days. it could be found that mean net of Cu- influxes showedthat the highest mean values of Cu- influx with the variousgroups of seed soaking pretreatments such as growth regulators(GA), amino acids (Glutamic). chloride solutions (NaCl).potassium solutions (KN2P04) and micronutrients sulphatesolutions (CUS04) followed a particular pattern about similarto that obtained with mean net influxes of phosphorus,manganese and iron during the same period.15- Concerning the third period (75- 140) days aftersowing. it could be found that :A- The highest mean value of net Zn- influx occurredwith plants whose seeds were soaked with IAA. whereas thelowest mean value existed in case of Proline. The other seedsoaking media could be arranged in the following descendingorder:Glutamic acid === NaC! --- FeS04 > IBA === GA === Asparticacid === KN03 > KH2P04 > NAA === MnS04 > MgCl2 === ZnS04 ===CUS04.Also, it seemed to be the highest mean values of Zninfluxwithin each group of seed soaking pretreatments viz.,growth regulators (IAA). amino acids (Glutamic), chloridesolutions (NaC!), potassium solutions (KN03) and micronutrientssulphate solutions (FeS04) followed a particularpattern about similar to that obtained with mean netinfluxes of phosphorus during the mention period.B- The mean values of Mn- influxes was varied widelyfrom seed soaking pretreatments in KH2P04 to Aspartic acidas a soaking solution. The descending order of the othersoaking solutions are :CUS04 > IBA > FeS04 > ZnS04 > GA > MnS04 > lAA > MgCl2 >KNOs > Proline > NaCl > Glutamic acid> NAA.C- The mean values of Cu- influxes was highest withsoaking in both IAA and Glutamic acid, whereas soaking inCUS04 resulted in the lowest mean net Cu- influxes. Theother soaking solutions are arranged descendingly in thefollowing order:FeS04 > Proline ::= MnS04 > IBA > Aspartic acid> ZnS04 >KH2P04 > GA ==: NaCl > MgCl2 > KN03 > NAA .D- The mean values of Fe- influxes was highest bysoaking in either Glutamic or Aspartic acids and the lowestwith soaking in NAA. The other soaking solutions arearranged descendingly in the following orderIBA > Proline > KH2P04 > IAA > FeS04 > MnS04 > ZnS04 >CUS04 > GA > KNOs > MgC12 > NaCI.Several mechanisms seemed to be involved; these mechanismswere suggested to be such as activation of the biochemicalprocesses in embryos, the influence on cell permeability,phosphate accumulation in seeds or trace-elements suchas zinc. manganese. copper and/ or iron or/ and theiraccompained cation/ anion in the soaking media.~--- .-. ------- 200 -According to that, a suggestion could be introducedthat soaking practice seemed to be more influential on grownplants than factors dealing with environmental conditions ofsaline soil. This was suggested to be a resultant ofinfluence of seed soaking on developed root system whosecontact with soil particles seemed to be more efficient thanwith fertilizer to supply the plant with total needs of differentelements and these detected later in the developedplants and grain yield.