Showing 5 results for Chlorophyll
Fatemeh Ghasemi, Reza Heidari, Rashid Jamei, Latifeh Poorakbar,
Volume 1, Issue 1 (12-2014)
Abstract
To assess nickel-induced toxicity in plants, Zea mays seeds were germinated and cultured on nutrient solution with nickel concentrations of 0, 50, 100 and 200 μM for a period of two weeks. Its effects on the growth, Hill reaction and photosynthetic pigments content were then investigated. The fresh and dry weight of leaves and roots increased in 50 μM nickel, but decreased in 100 and 200 μM. The decline in length of root and shoot were observed by increasing nickel concentration. According to the results, root and shoot showed differential growth response to various nickel concentrations. Nickel concentrations up to 100 μM caused increase in the content of chlorophyll a, but resulted in decrease at 200 μM nickel. No significant changes in chlorophyll b and carotenoids contents were observed. The rate of Hill reaction, as the ability of chlorophyll a in the reaction center of PSII680 to split water, decreased by increase in nickel concentration.
Mehrdad Rasouli, Abdollah Hatamzadeh, Mahmood Ghasemnezhad, Habibollah Samizadeh Lahiji,
Volume 4, Issue 1 (6-2017)
Abstract
In most parts of Iran, the presence of water and soil salinity in urban area results in problems for grass growth. One way to solve this problem is the use of plant growth retardant, such as trinexapac-ethyl (TE), which is common and routine in turf management. This study was performed to investigate the response of Agrostis stolonifera L., Agropyron desertorum L. and Festuca ovina L., grown in sandy loam soil, to TE and irrigation water salinity. Resu-lts showed that spraying turf grass with TE increased most of the vegetative growth characteristics and content of chlo-rophylls, carotenoids and proline in clipping leaves, whereas increasing the NaCl concentration in irrigation water resu-lted in steady reduction in the values of these parameters, except carotenoids and proline content, compared with the co-ntrol group. Both TE and salinity treatments decreased the plant heights, as well as the fresh and dry weight of clip-pings. In the species which were studied, Agrostis stolonifera turned out to be the most tolerant turfgrass. Results also indicated that the application of TE enhances salinity resistance by improving the percentage of green leaf, chlorophyll concentration and proline content and reduce clipping in the species studied
Raheleh Ahmadpour, Saeed Reza Hosseinzadeh, Nezam Armand, Somayeh Chashiani,
Volume 4, Issue 3 (12-2017)
Abstract
Water stress is one of the most important factors limiting the growth and yield of plants in many parts of the world. In order to evaluate the effects of water stress on some morphological, physiological and antioxidant enzyme activity traits of lentil, four lentil cultivars (i.e. Gachsaran, Kimia, Ziba and Robat) in four water deficit treatments including 25%, 50%, 75% and 100% of the field capacity (control) were studied in a factorial experiment, based on a completely randomized design with three replications. Water stress at 25 and 50% field capacity significantly decreased morpho-physiological traits and significantly increased antioxidant enzyme activity, proline and protein contents of all genotypes in comparison with the control group. Gachsaran and Robat cultivars were superior in most traits in comparison with the Kimia and Ziba cultivars. Under severe stress, the amounts of proline and protein contents, CAT and SOD enzyme activity were significantly higher in Robat and Gachsaran cultivars than those of the Kimiya and Ziba cultivars. Results showed that Robat and Gachsaran cultivars were probably affected less by water stress due to more stress tolerance using various mechanisms such as more antioxidant enzyme activity, increased proline, proteins and photosynthetic pigments contents. Studied traits were introduced as suitable markers for identification of drought tolerant genotypes. Accordingly, Robat and Gachsaran cultivars were introduced as tolerant cultivars for cultivation under rainfed conditions.
Hakimeh Oloumi, Fatemeh Nasibi, Hossein Mozaffari,
Volume 5, Issue 2 (9-2018)
Abstract
Medicinal plants are rich sources of secondary metabolites. Lepidium sativum possess active compounds and secondary metabolites, including polyphenol, anthocyanin, flavonoid compounds, which are of special pharmaceutical and economic importance. Melatonin as bio-stimulator compound has a regulatory role on the amount of secondary metabolites and plant tolerance to environmental stresses. In this study, the effect of exogenous melatonin on secondary metabolites production on Lepidium sativum plants was carried out in a completely randomized design with 5 melatonin treatments (0, 5, 10, 50 and 100 μM) and 3 replications. After applying the treatment, the growth rate and content of the photosynthetic pigments, the leaf water content, as well as the content of flavonoids, anthocyanins and total phenolic compounds were investigated. Seed treatment with melatonin, especially at concentrations of 50 and 100 μM, improved the growth parameters and content of photosynthetic pigments. High levels of melatonin also increased the plant's secondary metabolites, including anthocyanins, carotenoids, and plant phenolic compounds. These effects can confirm the role of melatonin as a growth regulator and its impact on plant growth and resistance.
Akbar Forghani, Amir Hossein Forghani, Maryam Altafi, Kazem Hashemi Majd, Omid Sofalian,
Volume 8, Issue 3 (10-2021)
Abstract
Most of agricultural lands in Iran are located in arid and semi-arid regions and are considered as saline soils. In order to investigate the interaction of salinity as well as potassium and calcium on the growth and yield of tomato plants, a factorial experiment was perfected in the form of randomized complete blocks, in hydroponic conditions, with three replicates per treatment. Experimental factors include salinity at three levels (0, 20, and 40 mM NaCl), potassium content form chloride, nitrate (0 and 15 mM), and calcium from chloride, and nitrate (with 0 and 10 mM (. The studied growth factors, including plant height, stem diameter, number of leaves, flowers and fruits and leaf chlorophyll decreased with increase NaCl. Treatment plants with Ca (NO3)2 at 40 mM NaCl, increased the shoot and root dry weight by 55% and 95%, respectively. In addition, application of Ca (NO3)2 in the medium with maximum salinity concentration resulted in an increase of 75% in chlorophyll content. The analysis of data showed that the increase of salinity was accompanied with increase sodium content level of tomato plants. However, the root potassium was observed to decrease. On the contrast to the root, potassium content showed no change in the organs from the root upwards. Also, the use of Ca (NO3)2 with 40 mM NaCl reduced Na+ content by 23% compared with plants treated only with 40 mM NaCl. According to the results, it seems that application of Ca (NO3)2 may improve chlorophyll content, dry weight, and modulate ion hemostasis and decreased the negative of salt stress in tomato plants.
