in order to evaluation of the relationship among protein markers and traits such as proline content variation, quantum efficiency of photosystem ii and field viability index, 20 genotypes of barely were studied in a randomized complete block design in the greenhouse experiment. plants were transferred to springhouse at the four leaf stage and were located at the temperature of 4°c for three wee...

In arid and semi-arid areas of the world, excessive mineral aerosol carried by air parcels is a common climatic incident with well-known environmental side effects. In this study, the role of sand-dust accumulation was investigated on various aspects of photosynthetic yield of Plantago lanceolata including chlorophyll (Chl) a, b, effective quantum yield of PSII photosystem (ФPSII), maximal quan...

Cells of the cyanobacterium Synechococcus 6301 were grown under illumination whose spectral composition favoured absorption either by the phycobilisome (PBS) light-harvesting antenna of photosystem II (PS II) or by the chlorophyll (Chi) a light-harvesting antenna of photosystem I (PS I). Cells grown under PS I-light developed relatively high PS II/PS I and PBS/Chl ratios. Cells grown under PS I...

abstract in order to study the effects of irrigation regimes on physiological traits, yield and water use efficiency of potato (solanum tuberosum l.) in mashhad weather condition, an experiment was conducted in 2009 at research field of the college of agriculture, ferdowsi university of mashhad, using factorial experiment based on randomized complete blocks design with 3 replications. experimen...

We have measured the radical pair quantum yield of reaction centers of photosystem II of green plants and of the purple bacterium Rhodobacter sphaeroides as a function of excitation density using sub-picosecond pulses at 77 K. The saturation behavior of both RCs can be described consistently by taking into account stimulated emission and the geometry of the polarized (magic angle) laser experim...

Melatonin was found in the fresh water characeae Chara australis. The concentrations (~4 μg/g of tissue) were similar in photosynthesizing cells, independent of their position on the plant and rhizoids (roots) without chloroplasts. Exogenous melatonin, added at 10 μM to the artificial pond water, increased quantum yield of photochemistry of photosystem II by 34%. The increased efficiency appear...

Plant biotypes that are resistant to S-triazines under most conditions often grow less vigorously and have lower quantum yields and lower maximum rates of photosynthesis. The photosynthetic reactions responsible for these effects were identified in whole leaves and thylakoids of nearly isonuclear lines of oilseed rape (Brassica napus L.). The lower quantum yield was a result of poor efficiency ...

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...

In some studies, tissues from plants that have been genetically transformed to overproduce antioxidant enzymes sustain less damage when abruptly exposed to short-term chilling in the laboratory. However, few studies have examined the performance of transgenic plants during longer-term growth under chilling conditions. We compared growth of transgenic cotton that overproduces glutathione reducta...

A 2-year field study was conducted in northern Greece to investigate the effect of nitrogen fertilization and irrigation on productivity of three Greek chickpea varieties (“Amorgos” “Serifos”, “Andros”). Chickpea, grown under irrigation regime (30 + 30 mm of water) and fertilized with 50 kg·N·ha−1 before planting and with 40 kg·N·ha−1 at blossom growth stage, produced more total dry biomass and...