DETERMINATION OF PHOTOSYNTHETIC RATE AT SEVERAL AROMATIC PLANTS

  • Stefania GADEA University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture 3-5 Mănăstur Street, 400372, Cluj-Napoca, Romania,
  • S.V. DATCA University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture 3-5 Mănăstur Street, 400372, Cluj-Napoca, Romania,
  • D.I. VARBAN University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture 3-5 Mănăstur Street, 400372, Cluj-Napoca, Romania,
  • Rodica VARBAN University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture 3-5 Mănăstur Street, 400372, Cluj-Napoca, Romania,
  • Ileana BOGDAN University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture 3-5 Mănăstur Street, 400372, Cluj-Napoca, Romania,
Keywords: photosynthetic rate, aromatic plants, CO2 infrared analyzer, leaf chamber

Abstract

SUMMARY Medicinal and aromatic plants are expressed by roots, rhizomes, leaves, flowers or fruits and the scientific interest for natural medicine and traditional practice of treatment increase more and more. The purpose of research are related with the theoretical and practical knowledge regarding the cultivation technology of the medicinal and aromatic species (Salvia officinalis, Ocimum basilicum and Thymus vulgaris), being interested also in the intensity of plants photosynthesis, during different vegetation periods. Establishing the photosynthesis rate is made with the help of CO2 infrared analyzer. This equipment determines the photosynthesis rate by analyzing the CO2 content in the leaf chamber, the photosynthesis rate being given by the difference of CO2 in the air and the one released by the leaf, on surface unit in μmol CO2/m2/s. The data taken with the help of this equipment are transferred after that to the LabPro interface, which with the help of a soft is transferred on PC to be interrelated. Determinations were made in five moment within the different vegetation phases: at 20 days from springing (control variant), before flowering, at flowering, at 10 days after flowering and at 20 days after flowering. There were used for each specie and vegetation phases a number of 5 plants, randomized and the experimental results were statistic interrelated with the help of the variant analyze. At Salvia officinalis L, the photosynthetic rate has low values in the first phases of vegetation (14,25 μmol CO2/m2/s), followed by a progressive growing which reaches a maximum of 16,64 μmol CO2/m2/s in the period of flowering. At 20 days after flowering, the rate of photosynthesis decreases at 14,22 μmol CO2/m2/s. At Thymus vulgaris L, it is registered 14,20 μmol CO2/m2/s at 20 days from springing , 15,12 μmol CO2/m2/s during the flowering period (the maximum of photosynthesis) and 14,17 μmol CO2/m2/s at 20 days after flowering. At Ocimum basilicum L., the rate of photosynthetic taken as control variant, is 14,23 μmol CO2/m2/s, followed by the progressive increase up to 16,13 μmol CO2/m2/s registered at flowering vegetation phase. This value overdue significant the rate of photosynthesis control. At 20 days after the reach of the maximum values registered, is noticed an average rate of photosynthesis of 14,19 μmol CO2/m2/s. The comparative analyze of the photosynthetic rate at studied species shows that the evolution during the determination period is similar; the maximum point of the photosynthetic rate is registered in the flowering phase. The maximum values of the photosynthetic rate differs depending on specie, being higher at Salvia officinalis, followed by Ocimum basilicum, the lowest values are registered at Thymus vulgaris.