ABSTRACT
We evaluated the compaction tolerance of some warm-season turfgrasses under shade and sunlight conditions in Riyadh, Saudi Arabia. Hybrid bermudagrass, Cynodon dactylon, cultivars 'Tifway' and 'Tifsport,' seashore paspalum (Paspalum vaginatum) and its cultivar 'Sea Isle 2000' were used. The study area was divided into two sections: one was exposed to sunlight and the other was maintained under 70% shade using a green plastic grille. Turfgrasses were planted using "sods" in beds containing a mixture of sand, silt, and peat moss (4: 1: 1, v/v). The soil was compacted using a locally-made 250 kg cylindrical roll, passing four times over the grown turfgrasses for 3 days/week. The results showed that plant height, leaf area, grass quality and color were decreased by compaction in both the shade and sunlight areas. Plant height in the shaded area with or without compaction was higher than in the sunlight area. Under compaction, 'Sea Isle 2000' was the shortest: 8.8 cm in the sunlight and 14.3 cm in the shade. For grasses grown in sunlight, compaction decreased grass height, and height was lowest (4.0 cm) for paspalum 'Sea Isle 2000' in January. In the shaded area, paspalum turfgrass retained its high quality (4.0) in April, May, and June. In the sunlight area, the grass quality was highest (4.0) in 'Sea Isle 2000' and the lowest (3.0) in 'Tifsport.' Paspalum turfgrass showed a higher color degree (4) than bermudagrass (2.5) in April, May, and June. Compaction also led to a decline in leaf area and fresh and dry weights of all grown turfgrasses. The grass density was high for paspalum turfgrasses, indicating that their resistance to compaction was greater than bermudagrasses. It can be concluded that the best compaction and shade-tolerant turfgrasses are 'Sea Isle 2000' and seashore paspalum.
ABSTRACT
Acacia saligna and Lawsonia inermis natural populations growing in Northern Saudi Arabia might be a valuable source of polyphenols with potent biological activities. Using high-performance liquid chromatography-diode array detection (HPLC-DAD), several polyphenols were detected tentatively in considerable amounts in the methanolic leaf extracts of A. saligna and L. inermis. A. saligna mainly contained rutoside, hyperoside, quercetin 3-glucuronide, gallic acid and p-coumaric acid, whereas those of L. inermis contained apigenin 5-glucoside, apigetrin and gallic acid. Strong antioxidant activities were found in the leaf extracts of both species due to the presence of hyperoside, quercetin 3-glucuronide, gallic acid, isoquercetin, p-coumaric acid, quercitrin and rutoside. A. saligna and L. inermis leaf extracts as well as hyperoside, apigenin 5-glucoside, and quercetin 3-glucuronide significantly reduced reactive oxygen species accumulation in all investigated cancer cells compared to the control. Methanolic leaf extracts and identified polyphenols showed antiproliferative and cytotoxic activities against cancer cells, which may be attributed to necrotic cell accumulation during apoptotic periods. Antibacterial activities were also found in both species leaf extracts and were twice as high in A. saligna than L. inermis due to the high composition of rutoside and other polyphenols. Finally, strong antifungal activities were detected, which were associated with specific phenols such as rutoside, hyperoside, apigenin 5-glucoside and p-coumaric acid. This is the first study exploring the polyphenolic composition of A. saligna and L. inermis natural populations in northern Saudi Arabia and aiming at the detection of their biological activities.
