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معاملة بذور الذرة الصفراء Zea mays L. بحامض السالسياليك واثرها في تحمل الشد المائي المستحث بمادة الكلايكول متعدد الاثلين == The treatment of Corn seeds (Zea mays L.) with salicylic acid and its effects on drought tolerance induced by polyethylene glycol (PEG)
Author name:
وسن فوزي عبد الحسین
General topic:
Biology
Specific topic:
Life Science
Degree:
Master
University:
University Of Basrah - Faculty Of Education
Language:
Arabic
University location:
Basrah
First pages:
24T3584 - p.pdf
Abstract:
The study was conducted in Plant physiology laboratory, department of biology, college of education for pure sciences, University of Basrah from 1/6/2015 till 10/7/2016 in order to evaluate the effect ofpretreatment (soaking) seeds of corn (Zea mays L.) cv. Baghdad 3with salicylic acid (SA) on germination, early seedlings growth and to minimize the effect of water stress induced with poly ethylene glycol (PEG). The study included the following experiments : 1 - Effect of SA and PEG on germination using a hydroponic culture and Hoagland solution in which corn seeds were soaked in three concentrations (0.1,0.3,0.5) mMof SA in addition to control treatment with distilled water for six hours. Water stress were induced with PEG at concentrations of 0 (distilled water),1%,2%,3%,6%,9% and 12%. This experiment indicated that the optimum soaking concentration with SA was 0.5 mM and that there was no germination at 12% PEG.2 - Effect of interaction between corn seeds pretreatment with DW, 0.5mM of SA for six hoursand PEG at all previous concentrations except 12%, on early corn seedlings growth using hydroponic culture and Hoagland nutrient solution, for three weeks.3 - Effect of interaction betweencorn seeds pretreatment with DW, 0.5 mM of SA for six hoursand water stress induced with PEG at 3% and 6% on vegetative growth using pots filled with a mixture of sand and peat moss for three months.The parameters were evaluated after each of the previous experiments, also , Biochemical test . Plant height, leaves number, root length and number, dry and fresh weight for shoot and roots, while the followingparameters were evaluated in corn leaves after pots experiment : 1 - Biochemical tests included : proline and glycine betain concentrations, total carbohydrates, total chlorophyll, sodium and potassium ions concentrations.2 - Leaves anatomical study to compare the effect of PEG inducedwater stress and the role of its interaction with pretreatment with SA on thegrowth and development of internal structure of corn leaves.The following results were estimated : 1 - Germination percentage : increasing water stress in the nutrient media reduced the % germination significantly when compared with control treatment. Seeds pretreatment with SA enhanced the germination percent and the highest percent was at interaction between PEG at 1%, 2% and SA at 0.5 mM.2 - Growth parameters for seedling at hydroponic culture indicated that plant height, fresh and dry weight for shoot and roots have increased significantly when seeds were pretreated with 0.5 Mm SA All theprevious parameters were reduced significantly under PEG induced waterstress especially at 9%. Interaction between SAand PEG caused apositive significant increases in all studied parameters especially atconcentrations less than 6% and 9% PEG.3 - Growth parameters for corn plants grown at pots have showed a significant increase when pretreated with SA compared with that treated with DW. PEG caused a significant decrease in the growth parameters IIIespecially at 6%. Interaction between DW and 6% PEG recorded the lowest growth in all studied parameters. 4 - Biochemical tests : There was a significant increase in total carbohydrates and total chlorophyll content in leaves of corn plants pretreated with SA in compare with that pretreatdwith DW while the content of proline and glycine betaine were higher significantly in leaves pretreated with DW.In case of PEG induced water stress, the highest total carbohydrates content was at 6%, highest chlorophyll content at 3% while proline and glycine betaine highest content were at 6% PEG. 5 - Sodium and Potassium Concentration : The highest potassium concentration was at plant treated with SA while the highest sodium concentration was at plant treated with DW. Increasing PEG concentrations caused a significant increase in potassium concentration and a significant decrease in sodium concentration. Interaction results revealed that the highest potassium and the lowest sodium concentrations were at interaction between SA and PEG at 6%. 6 - Anatomical study results revealed that increasing water stress effected the leaves tissues structures and this were cleared at vascular bundles tissues (xylem and phloem tissues) and bundle sheath. Upper and lower epidermis, polliform cells were also affected by increasing water stress.The anatomy of leaves also showed that there was a positive enhancement in the structure of leaves tissues in the plants grown from pretreated seeds with SA.
