Plant Process and Function

en 24-epibrassinolide improves the growth and essential oil of coriander leaves (Coriandrumsativum L.) under drought stress 24-epibrassinolide improves the growth and essential oil of coriander leaves (Coriandrumsativum L.) under drought stress باغبانی Horticulture كاربردي Applicable <div style="text-align: left;">Coriander (Coriandrum sativum L.) is used as an aromatic and medicinal vegetable. Plant growth regulators improve plant performance under unfavorable conditions. In this study, the interaction effects of 24-epibrassinolide (0, 0.5 and 1 µM) and three levels of drought stress (-2, -3.5 and -4.5 bars) were investigated on growth parameters and coriander leaves essential oil. The highest main stem length, diameter, shoot fresh weight, and shoot dry weight were obtained by 0.5 µM of 24-epibrassinolide (EBR) under -3.5 bar. Both 0.5 and 1 µM concentrations of 24-epibrassinolide protected leaves of chlorophyll a and b against the effects of water deficit. The plants under -3.5 and -4.5 bar water deficits showed more leaf electrolyte leakage compared to the control (-2 bar). The highest percentage of all six measured essential oil components (linalool, (e)-2-decenal, 2-hexa-decenal, carvone, α-pinene and (E)-2-dodecenal) were obtained under moderate and severe levels of regulated water deficit. Foliar spray of EBR 0.5µM under severe drought stress with -4.5 bar of matric potential increased the main essential oil compositions such as linalool, (E)-2-decenal and (E)-2-hexa-decenal.</div> Coriander (Coriandrum sativum L.) is used as an aromatic and medicinal vegetable. Plant growth regulators improve plant performance under unfavorable conditions. In this study, the interaction effects of 24-epibrassinolide (0, 0.5 and 1 µM) and three levels of drought stress (-2, -3.5 and -4.5 bars) were investigated on growth parameters and coriander leaves essential oil. The highest main stem length, diameter, shoot fresh weight, and shoot dry weight were obtained by 0.5 µM of 24-epibrassinolide (EBR) under -3.5 bar. Both 0.5 and 1 µM concentrations of 24-epibrassinolide protected leaves of chlorophyll a and b against the effects of water deficit. The plants under -3.5 and -4.5 bar water deficits showed more leaf electrolyte leakage compared to the control (-2 bar). The highest percentage of all six measured essential oil components (linalool, (e)-2-decenal, 2-hexa-decenal, carvone, α-pinene and (E)-2-dodecenal) were obtained under moderate and severe levels of regulated water deficit. Foliar spray of EBR 0.5µM under severe drought stress with -4.5 bar of matric potential increased the main essential oil compositions such as linalool, (E)-2-decenal and (E)-2-hexa-decenal. 24-epibrassinolide, Coriander essential oils, Linalool, drought stress 24-epibrassinolide, Coriander essential oils, Linalool, drought stress 45 54 http://jispp.iut.ac.ir/browse.php?a_code=A-10-557-3&slc_lang=en&sid=1 Neda Amiri Neda Amiri namiri10@yahoo.com No Department of Horticultural Sciences, Faculty of Agriculture, ShahidBahonar University of Kerman, Kerman, Iran Department of Horticultural Sciences, Faculty of Agriculture, ShahidBahonar University of Kerman, Kerman, Iran Najmeh Zeinalipour Najmeh Zeinalipour nzeinali@uk.ac.ir No Department of Horticultural Sciences, Faculty of Agriculture, ShahidBahonar University of Kerman, Kerman, Iran Department of Horticultural Sciences, Faculty of Agriculture, ShahidBahonar University of Kerman, Kerman, Iran Zahra Pakkish Zahra Pakkish zahrapakkish@uk.ac.ir Yes Department of Horticultural Sciences, Faculty of Agriculture, ShahidBahonar University of Kerman, Kerman, Iran Department of Horticultural Sciences, Faculty of Agriculture, ShahidBahonar University of Kerman, Kerman, Iran