واكنش افتراقي چهار ژنوتيپ انگور ايراني به تنش كم آبي ايجاد شده توسط پلي اتيلن گليكول در شرايط درون شيشه اي

چكيده انگليسي :

AbstractGrapevine is one of the important small fruit crops in Iran and other parts of the world that in terms of food andpharmaceutical is of more importance This plant has a wide ecological range of adaptability that can be seen fromequator to the north and south regions of the earth Grapevine by deep roots and mechanisms of tolerance able toendure somewhat abiotic stresses drought and salinity In recent years low rainfall and low water availability foragriculture has led to the identification and selection of genotypes and tolerant cultivars One method of evaluationand selection of drought tolerant cultivars is the use of in vitro techniques that simulate controlling environmentalstressors in vitro and pave the way to more concisely study plant responses to drought stress The present study wascarried out in frame of factorial 5 x 4 completely randomized design with three replicates to investigate theresponses of four Iranian grape genotypes Askari keshmeshi Ghermez Qazvin Yaqooti sefid and Shahani to deficit water stress induced by polyethylene glycol PEG in in Vitro conditions Micro cuttings with length of 1 1 5 cm of grapevine genotypes were prepared disinfested and planted in the MS stock medium supplemented with0 7 mg indole butyric acid IBA After rooting microcuttings were transferred to MS medium containing variouspercent of polyethylene glycol 0 3 6 9 and 12 Results showed significant reduction in all measured vegetativeparameters including fresh and dry weight of shoot and root shoot length number of nodes per shoot and leaf areaexposed to different levels of drought treatments There were significant differences in the vegetative characteristicsof the genotypes under study The highest mean of the fresh weight of the shoot was related to genotype Yaqootisefid and the lowest one to genotype Askari respectively The shoot length of the Askari and Yaqooti Sefidgenotypes was more in comparison with other two genotypes Ghermez Qazvin and Shahani Askari genotype hadthe highest leaf area while Yaqooti had the lowest one The highest mean of the root fresh weight was observed inShahani genotype In terms of root dry weight there was no any significant difference among the genotypes All thephysiological parameters like relative water content leaf proline content lipid peroxidation MDA content and ionleakage were affected by drought treatments With increasing drought levels leaf relative water content decreasedand ion leakage proline and MDA were increased Askari genotype had the largest and more relative water contentthan other genotypes There was no significant difference among other genotypes in this respect Ghermez Qazvinand Yaqooti Sefid genotypes had the highest rate of ion leakage while that was lowest for Shahani The highest andlowest amounts of MDA were related to Shahani and keshmeshi Ghermez Qazvin genotypes respectively Activities of antioxidant enzymes are also significantly affected by different levels of osmotic potential so that withincreasing levels of PEG increases in activity of catalase peroxidase and ascorbate peroxidase were observed in thegenotypes under study Shahani genotype indicated more antioxidant activity than other genotypes and Askari wasthe later one There was a significant negative correlation among morphological growth parameters with proline ionleakage and amount of malondialdehyde MDA and the activity of antioxidant enzymes With respect to the resultsof this study particularly of the physiological parameters and activities of antioxidant enzymes could be concludedthat genotypes Shahani Keshmeshi Ghermez Qazvin and Yaqooti Sefid and Askari showed more less andmoderate tolerance to water deficit stress respectively Key wordsOsmotic Stress Polyethylene glycol Grapevine genotypes Physiological parameters Antioxidantenzymes

مهري، حميدرضا

واكنش افتراقي چهار ژنوتيپ انگور ايراني به تنش كم آبي ايجاد شده توسط پلي اتيلن گليكول در شرايط درون شيشه اي

تنش اسمزي , شاخص هاي فيزيولوژيك , آنزيم هاي آنتي اكسيدان