title: Enhancing stress growth traits as well as phytochemical and antioxidant contents of Spiraea and Pittosporum under seaweed extract treatments.
abstract: Seaweed extracts (SWE) might play an important role in enhancing growth and phytochemical composition of medicinal shrubs. In this study, we investigate the morphological, physiological and biochemical effects of irrigation levels (100% and 50% of the evapotranspiration rate) coupled with a weekly treatment of SWE of Ascophyllum nodosum at 5 and 7 mL L(-1) as a soil drench or foliar spray on Spiraea nipponica "Snowmound" and Pittosporum eugenioides "Variegatum" grown in containers under controlled greenhouse conditions. In addition, the phenolic and flavonoid content, antioxidant capacity and lipid peroxidation in both plant species was largely enhanced while the proline accumulation was reduced. After 8 weeks of treatments, drought condition reduced plant vegetative growth and gas exchange, as well as leaf water potential, but increased the phenolic and flavonoid contents in leaves, their antioxidant capacities and proline content. The application of SWE enhanced the performance of both species during mild drought conditions by means of increasing leaf number and area, dry weights, plant height, gas exchange and leaf water potential. The maximum vegetative growth, physiological performance and phytochemical composition of both species was achieved using the drench SWE treatments (5 and 7 mL L(-1)) in moderate drought conditions, which improved the plant water status, stomatal conductance, and photosynthetic rate. SWE enhanced plant growth and the phytochemical composition and antioxidant capacity of plant leaves of both species during moderate drought conditions.
authors.affiliation: Biodiversity Institute of Ontario, University of Guelph, Guelph, ON N1G 2W1, Canada; Department of Floriculture, Ornamental Horticulture and Garden Design, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria, Egypt. Electronic address: hosammail2003@yahoo.com.
authors.forename: Hosam O
authors.initials: HO
authors.lastname: Elansary
authors.affiliation: Department of Pharmacognosy with Medicinal Plants Unit, Medical University of Lublin, 1 Chodzki Str, 20-093 Lublin, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Skalicka-Woźniak
authors.affiliation: Biodiversity Institute of Ontario, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: Ian W
authors.initials: IW
authors.lastname: King
mesh_terms: D000704:Analysis of Variance; D000975:Antioxidants / Q000032:analysis*; D018533:Biomass; D015227:Lipid Peroxidation; D064209:Phytochemicals / Q000032:analysis*; D018515:Plant Leaves / Q000033:anatomy & histology; D011392:Proline / Q000378:metabolism; D019655:Quantitative Trait, Heritable; D019685:Rosales / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism; D012624:Seaweed / Q000737:chemistry*; D031992:Spiraea / Q000033:anatomy & histology / Q000254:growth & development* / Q000378:metabolism; D013312:Stress, Physiological; D014867:Water
chemical_list: D000975:Antioxidants; D064209:Phytochemicals; D014867:Water; D011392:Proline
keywords: Antioxidants; Drought; Pittosporum; Seaweed extract; Spiraea