اثرات ریزگرد و تنش خشکی بر برخی خصوصیات فیزیولوژیکی در گیاه ماش (vigna radiata l.)

ریزگرد مشکل نوظهوری است که همراه با تنش خشکی مناطقی از غرب و جنوب کشور را درگیر کرده است. به منظور بررسی تاثیر این دو عامل بر خصوصیات فیزیولوژیکی گیاه ماش (vigna radiata l.)، آزمایشی بصورت کرت‌های خرد شده بر پایه طرح بلوک‌های کامل تصادفی با 4 تکرار در تابستان سال زراعی 1394 در مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی لرستان انجام شد‌. عامل تنش خشکی از طریق آبیاری پس از 70 (آبیاری نرمال)، 80، 90 و 100 میلی‌متر تبخیر از تشتک تبخیر کلاس الف در کرتهای اصلی و عامل شبیه‌سازی ریزگرد شامل سه سطح شاهد (بدون ریزگرد) و کاربرد 50 و 100 میلی‌گرم در متر مکعب ریزگرد در کرت‌های فرعی قرار گرفت. نتایج نشان داد که میزان کلروفیلa تحت تاثیر هم‌افزائی افزایش غلظت ریزگرد و تشدید تنش خشکی بطور معنی‌داری کاهش یافت. تنش خشکی همچنین باعث کاهش معنی‌داری در کلروفیل‌های b وa+b و همچنین قندها و پروتئین‌های محلول برگ گردید. رابطه خطی معنی‌دار و منفی میان تنش خشکی با عملکرد دانه و مثبت میان تنش خشکی با محتوی پرولین برگ در گیاه ماش مشاهده شد. درمجموع گیاه ماش علی‌رغم کاهش عملکرد دانه، سعی در تعدیل تنش خشکی از طریق تنظیم اسمزی با افزایش اسمولیت‌های پرولین و قندهای محلول نمود و واکنش تقابلی به ریزگرد نشان نداد.

Effect of Aerosols and Drought Stresses on Some Physiological Traits of Mungbean (Vigna radiata L.)

Introduction: Mungbean (Vigna radiata L.) is affected by some different stresses. Aerosol is one of the new problems that is accompanied by a drought stress in some Western and Southern parts of Iran (Marsafari, 2011). The increase of irrigation intervals reduces chlorophyll a and b and increases proline amino acid content of basil leaf (Gholdani, 2012). Zadeh Bagheri (2014) has indicated that the accumulation of sugar, chlorophyll, potassium and proline content in beans can be cause of droughtresistance in plants. The objective of this study was the evaluate aerosols along with drought stress effects on mungbean photosynthetic pigments, nitrogen compounds, soluble sugars and grain yield. Materials and Methods: The research was conducted to study the effect of drought and aerosol stresses on physiological traits of mungbean (Vigna radiata L.) in the Lorestan Agricultural and Natural Resources Research and Education Center which lies at latitude 33° and 29’ N, longitude 48° and 18’ E, and an altitude of 1195 m above sea level in 2015. Before the beginning of the experiment, soil samples were taken in order to determine the physical and chemical properties. A split plot design based on RCBD was used with four replications. Four different irrigation regimes after 70 (well irrigated treatment), 80 , 90 and 100 mm evaporation from pan class A were assigned to main plot, and three aerosol levels did not contain aerosols (control) and using 50 and 100 mg m3 aerosols in clay soil sours were randomized in subplots. Chlorophyll a, chlorophyll b, chlorophyll a + b, soluble sugars and protein content in leaves were measured at flowering period and grain yield was measured at harvesting time. The data were statistically analyzed using the MSTATC and SAS softwares. Comparison of means was performed using the Least Significant Difference test at 5% probability level. Results & Discussion: Result showed that chlorophyll a, chlorophyll b, chlorophyll a+b was significantly affected by drought stress. Aerosol only affects chlorophyll a. Drought and aerosol stresses interaction had a significant effect on chlorophyll a and decreased it. The highest amount of chlorophyll a (0.015 mg g1 FW) in leaves was achieved by normal irrigation in different levels of the aerosol. Chlorophyll b, chlorophyll a + b significantly reduced by drought stress from 0.0083 and 0.024 in normal irrigation condition to 0.0037 and 0.01 mg g1 FW in severe drought stress, respectively. Sugar of leaves was also significantly reduced by drought stress from 1.86 in normal irrigation condition to 4.62 mg g1 FW in severe drought stress. Protein content was also significantly affected by drought stress and decreased from 0.15 in normal irrigation condition to 0.05 mg g1 DW in severe drought stress. Significant and negative linear relationship was found between drought stress and grain yield, but found a significant and positive linear relationship between drought stress and leaf proline. Conclusion In addition, according to data analysis in this experiment, the synergistic effect was found in higher levels of drought stress and aerosols on chlorophyll a. Chlorophyll b, chlorophyll a + b, soluble sugars and protein contents significantly decreased by drought stress. Also, Significant and negative linear relationship was found between drought stress and grain yield, but between drought stress and leaf proline was found to be significant and positive. Therefore, it seems that provision of water requirement of mungbean plant in the region, while preventing the decrease in grain yield, does not have a negative effect of aerosols on the plant. Key words: chlorophyll a, chlorophyll b, chlorophyll a+b, osmatic adjustment, grain yield. References Gholdani, M. 2012. Effect of irrigation intervals on some morphophysiological traits of basil (Ocimum basilicum L.) ecotypes. Iranian Journal of Field Crops Research, 10(2):412420 (In Persian with English Summary). Marsafari, M., Asoudar, M.A. and Kordi, S. 2011. Aerosol resources and adjust their harm effects. Second national conference on critical management. Tehran. Iran. doi: http://www.civilica.com/PaperNCEVSLL02NCEVSLL02_388 (In Persian). Nourian, M.H., Zabihi, H. R. and Oveisi, M. 2015. Evalution of biofertilizers and B foliar application effects on grain yield in drought stress condition. Soil researches (Soil and Water Scince), 29(4): 179186 (In Persian with English Summary).