The study was carried out to evaluate the effects of various doses foliar application chitosan on spinach growth, yield, and quality characteristics (including chlorophyll-a, chlorophyll-b, total chlorophyll, carotenoids, ash, main nutrient contents). Randomized Completely Block Design (RCBD) used set up field experiment, with six treatment combinations [T0 = Control (no application), T1 100 pp...

A mild tryptic digestion of chloroplast membranes eliminates the effects of saturating concentrations of cations (3 to 5 millimolar MgCl(2)) on chlorophyll fluorescence yield, membrane stacking, and photosystem II photochemical efficiency in spinach. At the same time, the negative surface potential of the membranes is increased (by trypsin) as revealed by studies with 9-aminoacridine. High conc...

Methods for the cryopreservation of protein import and integration in pea chloroplasts and of protein import or protein synthesis in tobacco mitochondria were modified to yield enzymatically active cryopreserved etioplasts from barley (Hordeum vulgare L.). The cryoprotectants ethylene glycol and dimethy sulfoxide were about 64 and 77% effective, respectively, for the cryopreservation of etiopla...

understanding of physiological responses of salt tolerance might be lead to identify main salt tolerance mechanisms and essential approaches for improving grain yield stability, and also to select salt tolerant wheat cultivars. thus, the effects of salinity were investigated on grain yield and some of the characteristics related to salt tolerance. six wheat cultivars (roshan, kavir, karchia, ga...

The effects of natural, overwintering conditions on photosystem I and photosystem II activity were examined in isolated thylakoids of periwinkle (Vinca minor L.), an endemic, cold-tolerant, herbaceous evergreen. DCMU-Insensitive photosystem I activity (ascorbate/dichlorophenolindophenol --> methylviologen) exhibited a twofold increase in light-saturated rates upon exposure to low temperature an...

The present study was aimed to assess salt tolerance of some newly developed and candidate cultivars of wheat using gas exchange and chlorophyll fluorescence parameters. Ten wheat cultivars including five newly developed (S-24, Saher2006, Fsd-2008, Lasani and Inqlab-91) and five candidate (P.B-18, M.P-65, S.H-20, AARI-10 and G.A-20) were grown in sand culture. Salt stress (150 mM NaCl in Hoagla...

The photosystem II (PS-II) reaction center is composed of several polypeptides which contain carotenoids and chlorophyll. Three pigment-free extrinsic proteins, with masses 33, 24, 18 kDa, are involved in the oxygen evolving system [1]. One of the extrinsic proteins, a 33 kDa polypeptide, accelerates a dark step in the oxygen-evolving reaction [2] and preserves the binding of the Mn atoms to th...

The objective of this study was to investigate the effects of foliar applications of potassium and zinc on the fruit yield and quality as well as leaf nutrient concentrations of pistachio cv. ‘Chrokeh’. The experiment was conducted based on a completely randomized block design with nine treatments and three replications per treatment. Treatments were three levels of K2SO4 (0, 1 and 2%) and thre...