Morteza Saberi; Alireza shahriari; Marziyeh bozorgmehr
Abstract
An experiment was performed aimed to investigate the effects of priming and salinity on germination and seedling growth of Stipagrostis plumose in factorial test and completely randomized design with four replications in laboratory condition. The first factor was priming consist of salicylic acid with ...
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An experiment was performed aimed to investigate the effects of priming and salinity on germination and seedling growth of Stipagrostis plumose in factorial test and completely randomized design with four replications in laboratory condition. The first factor was priming consist of salicylic acid with three levels (100, 200 and 300 mg/l), gibberellic acid with three levels (125, 250 and 500 ppm), ascorbic acid with three levels (100, 200 and 300 mg/l), and water as control, and the second factor was salinity treatment in six levels (0, 0.2, 0.4, 0.8, 1.2, 1.6 m/l). The measurement characteristics were speed of germination, percent of germination, root length, shoot length, seedling length and seed vigor. Results indicated that salt stress had inhibitive effect on germination and early seedling growth of S. plumosa. All chemical stimulators increased the germination characteristics of this plant. Also, the interaction of the tested treatments showed that gibberellic acid 250 ppm has the highest effect on improvement of germination characteristics under all levels of salinity stress. We conclude that priming seeds by gibberllic acid can increase resistance the germination of S. plumosa in areas prone to salinity.
Hamidreza Mirdavoodi; Adele Jalili; Ziba Jamzad; Ali Famaheini
Abstract
Classification of species in plant functional types (PFTs) according to Grime’s CSR theory has been found useful in understanding ecosystem functioning and processes and in quantifying variation along environmental gradients. The aim of this study was to assess variations in CSR strategies along ...
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Classification of species in plant functional types (PFTs) according to Grime’s CSR theory has been found useful in understanding ecosystem functioning and processes and in quantifying variation along environmental gradients. The aim of this study was to assess variations in CSR strategies along stress and grazing gradients in Meyghan playa of Arak. The strategy of plant species was determined according to the Grime’s CSR strategies, based on Pierce’s method. Random- Systematic design was applied to sampling. Two-way indicator species analysis (TWINSPAN) was applied to classification of the ecological plant groups, and partial canonical correspondence analysis (pCCA) was used to identify relationship between environment factors, disturbance and the plant groups studied, using the PC-ORD4.17 and CANOCO4.5 software, respectively. Among the factors that affect plant functional types and the structure of vegetation, soil salinity as a stress factor and grazing as a kind of disturbance were studied. Results showed that stress-tolerant peaked in conditions of high salinity. Competitors with a frequency of 14.3% were mostly present in conditions of low salinity and disturbance/light grazing. Ruderals with a frequency of 7.1% were mostly present in condition of overgrazing. The presences of competitor in protected areas with low soil salinity confirmed the theory of appearance of competitive strategy in low/stress-free areas and light/graze-free. Therefore, it may be possible to use Grimes’s PFTs for assessing environmental constraints and predicting whether a species with a specific strategy is likely to be positively or negatively affected by changes in environmental stress due, for instance, to climate change.
