The most important impacts of climate change relate to temperature and precipitation. Precipitation is particularly important, because changes in precipitation patterns may lead to floods or droughts in different areas. Also, precipitation is a major factor in agriculture and in recent years interest has increased in learning about precipitation variability for periods of months to annual and seasonal trends and change points had been analyzed for 22 rainfall stations in Fars province during 1972 to 2011. Mann-Kendall non-parametric test and Sen’s method had been used to determine positive or negative trends; also Pettitt test, Standard normal homogeneity test, Buishand range test, Von Neumann ratio, for detection of change points in the time series had been implemented. The TFPW approach had been used in order to decline the effects of autocorrelation and serial correlation on Mann-Kendall test. The results of Mann-Kendall test and Sen’s Method showed decreasing trend for all rainfall stations except for the Monje station. But, no significant trends were observed in all stations. Also, the results indicated that the precipitation has not occurred nonhomogeneity; whereas all test indicated there is no change point on precipitation time series. No change and abrupt shift were visible in the precipitation time series except in winter for Ali Abad Khafr; and Ali Abad Khafr; Tangab and Ramjerd based on pettitt test and Standard normal homogeneity test, respectively.
هدف: بگونیا یکی از رایجترین گیاهان زینتی در جهان است و امروزه توجه ویژه ای به استفاده از بیوتکنولوژی و مهندسی ژنتیک در تولید اقام جدید با فرم های متنوع در این جنس شده است. این آزمایش با هدف بهینه سازی باززایی و انتقال ژن در این گیاه انجام شد تا زمینه ی لازم برای انتقال ژنهای ارزشمند را فراهم کند.
مواد و روشها: ابتدا شاخهزایی ریزنمونههای لایه سلولی نازک دمبرگ گونه B. soli-mutata در محیط کشت MS حاوی سیتوکینینهای Kin یا TDZ (2/0، 1 و 2 میلی گرم در لیتر) در ترکیب با NAA (0 و 2/0 میلی گرم در لیتر) مورد ارزیابی قرار گرفت. برای همکشتی و تولید گیاهان تراریخته، ریزنمونه دمبرگ بگونیا با باکتری A. tumefacians نژاد LBA4404 حاوی ژنGUS و ژن گزینشگر NPTII در محیط کشت MS حاوی یک میلیگرم در لیتر Kin و 2/0 میلیگرم در لیتر NAA کشت شد. برای تایید تراریختی گیاهچههای بدست آمده، از واکنش زنجیرهای پلیمراز با آغازگرهای ژنهای GUS و VIR و آزمون ارزیابی Gus استفاده شد.
نتایج: نتایج حاصل از این بررسی نشان داد به لحاظ باززایی شاخه سیتوکینین Kin نسبت به TDZ برتری دارد و اضافه کردن NAA به محیط کشت در هر دو تیمار سیتوکینین باعث بهبود تمام صفات شد. لذا برای همکشتی از محیط کشت حاوی یک میلیگرم در لیتر Kin و 2/0 میلیگرم در لیتر NAA استفاده شد. طی فرایند تولید گیاهان تراریخته، بعد از 4 ماه همکشتی 2000 ریزنمونه با باکتری در محیط کشت انتخابی حاوی 50 میلیگرم در لیتر کانامایسین، در مرحله سازگاری 17 گیاهچه بدست آمد که تراریختی 7 گیاهچه با استفاده از واکنش زنجیرهای پلیمراز و آزمون ارزیابی Gus تایید شد.
نتیجه گیری: نتایج این بررسی نشان داد درصد تراریزش در این گیاه پایین است و بهینه کردن شرایط برای افزایش کارایی انتقال ژن در آن از اهمیت زیادی برخوردار است.
Lack of regional climatic data is great challenge for agroclimatic studies. In this research, the influence topography on RegCM4 model results was investigated. In order of determine the role of topography on improving the results of RegCM model, two topographic datasets (GTOPO, GMTED) were used for a specific period of time and similar conditions to run the model. The experiments were done with lateral boundary conditions obtained from The NCEP-DOE Reanalysis 2 (NNRP2) dataset at 2.5° × 2.5° latitude-longitude horizontal resolution. The sea surface temperature (SST) for the corresponding regional climate simulations were prescribed from the National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation SST (OISST) dataset with a weekly temporal resolution and 1° × 1° spatial resolution. The topographical output of the model showed an increase of elevation in the Caspian sea coast [max (GMTED-GTOPO) = 254 m], while in some areas of Alborz mountains a decrease in elevation [max (GMTED-GTOPO) = -400 m] was observed. Due to higher elevation of GTOPO in the Alborz Mountains, the derived speed of this simulation is relatively higher than GMTED, which could reach as high as 1.6 m/s during winter season. The highest precipitation difference occurred during spring season in the vicinity of the area where 400 m of decreased elevation was observed, with amounts as high as 16 mm/day (80% increase in precipitation). The temperature differences followed closely the topographical differences. In the seashore areas, where there was increased elevation, temperature decreased correspondingly (max. of -2.4°), whereas in mountainous areas with decrease in elevation, the temperature increase was observed (max. of 1.2°). The findings from this research identified, the modified data (GMTED) is improving the results of the model and should be replace the old data (GTOPO) in future research.
Drought has significantly affected the environmental and socio-economic conditions in Iran. Three drought indices were used for monitoring drought intensity and duration in Kashafrood basin (northeast of Iran). The standardized precipitation Index (SPI), Precipitation Index Percent of Normal (PNPI) and Agricultural Rainfall Index (ARI) were calculated for the base period (1961-1990). All these indices were used to assess future drought in Kashafrood basin under climate change attributed to low and high greenhouse gas emission scenarios (SRES B2 and A2, respectively) for 3 periods (2010-2039, 2040-2069 and 2070-2100). Projected changes in precipitation, temperature and potential evaporation were simulated by statistical downscaling of HadCM3 outputs. Main results showed: (i) slight increase in precipitation means, around 2.2% to 5.4% under A2 scenario and 6.8% and 8.6% under B2 scenario. (ii) Slight increase in maximum temperature, around 4.6 oC to 5.6 oC for A2 scenario and 4.25 oC and 4.6 oC under B2 scenario. (iii) Slight increase in minimum temperature, around 1.6oC to 1.9 oC under A2 scenario and 1oC and 2.23oC under B2 scenario. (iv) Higher drought frequency associated with global warming was demonstrated by all indices for both scenarios. Such an increase in drought frequency would have major implications for natural resources management, water security planning, water demand management strategies, and drought relief payments.