Effect of nitrogen, phosphorus and flower stage of development on carotenoids and oil content of marigold (Tagetes patula L.)

   Seeds of marigold collected from local ornamental plants were grown at the farm of the Faculty of Agricultural Sciences, University of Gezira, Wad Medani, Sudan, during the 4th of March, 2007. The objective of the study was to investigate the effect of N, P and flower stage of development on carotenoids and oil contents of marigold (Tagetes patula L.). The study consisted of three rates of N (0, 43 and 86 kgha-1) and two P levels (0, 41 kg P2O5 ha-1). Flowers were harvested at the unopened, newly opened, mature and over mature stages. Treatments were arranged in a randomized complete block design with three replicates. Nitrogen and phosphorus fertilizers significantly increased plant height and number of branches of marigold. However, they did not affect flower carotenoids content. Marigold flowers contained about 5 different carotenoids including lutein, the major component and β-carotene. When compared with salad rocket which is a lutein rich plant, most of the lutein of marigold flowers was present in the esterified form in contrast to rocket leaves, in which case lutein was largely in the free form. Five carotenoids types appeared in marigold flowers 15 days after flower opening and less types were observed in younger and older flowers. The seeds of marigold contained 1.5% of fixed oil, the major fatty acid of which was linoleic acid.   تمت زراعة بذور الماريقولد التي جمعت من نباتات زينة محلية  في مزرعة  كلية العلوم الزراعية، جامعة الجزيرة، وادمدني، السودان, في الرابع من مارس, 2007. الهدف من الدراسة هو بحث تاثير سماد النيتروجين والفسفور ومراحل نمو الزهرة على صبغة الكاروتين ومحتوى الزيت في زهرة الماريقولد (Tagetes patula L.)   كانت مستويات النيتروجين صفر، 43، 86 كجم نيتروجين/هكتار ومستويات سماد الفسفور صفر, 41 كجم P2O5/هكتار. حصدت الازهار في مراحل نمو مختلفة وهي: قبل ان تتفتح، ومباشرة بعد تفتح الزهرة ومكتملة النضج وبعد 15 يوما من التفتح. تم استخدام تصميم القطاعات العشوائية الكاملة. أوضحت نتائج التجربة  أن المعاملة بالنيتروجين والفسفور أدت الى زيادة معنوية في طول النبات وعدد الافرع في نبات الماريقولد، ولكنها لم تؤثر على محتوى الكاروتينات الموجودة في أزهار الماريقولد كما أوضحت طريقة كروماتوغرافيا الطبقة الرقيقة أن أزهار الماريقولد تحتوي على حوالي 5 أنواع مختلفة من الكاروتينات بما فيها ليوتين وبيتاكاروتين. الليوتين الموجود في الماريقولد يوجد بصورة مرتبطة في شكل إستر مقارنة بالليوتين الموجود في الجرجير والتي يوجد فيها الليوتين بصورة حرة. ظهرت 5 أنواع من الكاروتينات في زهرة الماريقولد بعد 15 يوم من تفتح الأزهار، ووجدت نسبة أقل في الأزهار الأقل والأكبر عمراً. تحتوي بذور الماريقولد على1.5% من الزيوت الثابتة  والمكون الأساسي لها من الأحماض الدهنية هو حمض اللينوليك.     &nbsp

Total phenolic content and antioxidant capacity of basil (Ocimum basilicum L.) leaves from different locations

The present study was carried out to determine the antioxidant activity and total phenolic content of Ocimum basilicum collected from different regions of the world. The accession V1 is from Sudan, V2 from Iraq, V3 from Germany, V4 from Thailand, V5 from Russia and V6 from Maldives. The extracts from six basil accessions were analysed for their DPPH free radical scavenging activity and their total phenolic content (TPC). The results suggest that the highest antioxidant activity was found in V6 (from Maldives) and the lowest antioxidant activity was found in V4 (from Thailand). The highest amount of phenolic content was found in V6 (from Maldives) and the lowest phenolic content was found inV4 (from Thailand). This study shows that basil is a good source of free-radical scavenging compounds that have their traditional medicinal applications

Effect of plant ontogeny on yield and chemical constituents of essential oil in Sweet basil (Ocimum basilicum L.) grown in Sudan

Sweet basil (Ocimum basilicum L.), belonging to family Lamiaceae, is very important for its therapeutic and cosmetic potential. The yield and constituents of essential oils in plants are highly dependent on the harvesting time. This study was carried out to assess the effect of plant ontogeny on essential oil yield and chemical constituents for four sweet basil accessions cultivated under irrigation conditions. The essential oils were hydro-distilled from the leaves harvested during the stages of pre-flowering, at flowering and post-flowering. The chemical constituents were determined by GC-MS. The results reveal that the essential oil content ranged from 0.1% to 0.2% at the pre-flowering stage, whereas the oil content obtained at the post-flowering stage was 0.1% for all investigated accessions. The highest essential oil content was recorded at flowering stage (0.2-0.5%). The two wild Sudanese accessions had the maximum content (0.5%). The major chemical constituents, linalool, citral, methyl eugenol, and eucalyptol reported at different developmental stages, varied between 5.73% and 32.93%