تاثير اسپرميدين روي تحمل به سرما در بذور و بوته هاي خيار

چكيده انگليسي :

AbstractOne of the most important factors limiting plant growth and crop production in many parts of the world has beenconsidered to be low temperatures Cucumber is a warm season crop and is sensitive to cold With exception ofsouthern and central part of the country the rest are subjected to lower temperatures which cause chilling injury onwarm season crops early in the season There are different methods for controlling chilling injury one of thismethods is application of plant growth regulators Spermidine from polyamine group is one of the growth regulatorsthat in the recent years its use in controlling chilling injury has been studied Therefore a greenhouse study includesseveral experiments were performed to determine the effects of spermidine on the cold tolerance of cucumbercultivar Rashid in the early stages of growth All experiments were done as completely randomized designwithhormone levels included zero 0 1 0 5 and 1 mM spermidine with four replications at College of Agricultureof Isfahan University of Technology Experiments were performed in the imbibition completing germination andseedling stages In imbibition stage seeds after treatment with the hormone were incubated for 15 days in 13 C Incompleting germination stage seeds were exposedto 20 C for two days and then treated with hormones theremaining 13 days theywere kept at temperatures 15 13 11 or 9 C For seedling stage seeds were germinated for 7days at 20 C and then treated with hormones and incubated in 9 or 6 C temperatures under light photoperiod 8hours light and 16 hours dark for remaining 8 days During and at the end of each experiment measures such asgermination percentage the average days to germination length of shoot and root fresh and dry weight of shoot androot ion leakage of shoot and root proline of shoot and root was measured Briefly the findings in this studyshowed that application of spermidine in low concentrations increased growth at low temperatures compared withcontrol It also became clear that the imbibition step towards completing germination and seedling stages isrelatively more sensitive to chilling injury Overall the experiments showed that concentration of 0 5 mMspermidine in most cases increased cold resistance improved growth etc in cucumber seedlings Also in mostcases concentrations of more than 0 5 mM spermidine demonstrated inhibitory effect on cucumber growth Tocompare the effects of temperature and its interaction with the hormone data of four experiments of completinggermination stage analysed as split plot experiment four main plots and four sub plots The results showed thatreducing the temperature in this stage redused most of the growth parameters significantly Significant interactionsbetween hormone concentration and temperatureswere observed so that effect of different hormone concentration onshoot and root length and root fresh weight was depened on temperatures In the evaluation of cucumber coldtolerance factors such as root length fresh weight of root and shoot and proline showed better responses whereasion leakage in cucumber plants did not responed efficiently Key Words Cucumis sativus Chilling injury Spermidine

سليماني،محمد

تاثير اسپرميدين روي تحمل به سرما در بذور و بوته هاي خيار

سرمازدگي , پلي آمين ها