hosein Mirzaee nodoushan; Hasan rouhipour; zeynab zare; fereshte asadi korom; salman zare
Volume 22, Issue 4 , March 2015, , Pages 768-777
Abstract
The research was conducted based on genetic variation of a black saxaul (Haloxylon aphyllum) plant population to find possible differences between the genotypes of the population, confronting various levels of water stress. A great number of progenies of four genotypes of the species were studied under ...
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The research was conducted based on genetic variation of a black saxaul (Haloxylon aphyllum) plant population to find possible differences between the genotypes of the population, confronting various levels of water stress. A great number of progenies of four genotypes of the species were studied under four levels of water stress, field capacity, 20, 50, and 80% of available water by the plant, using a factorial statistical model based on randomized complete block design. Branch number and length, main-stem and crown diameter, leaf chlorophyll content and leaf osmotic potential were recorded during and at the end of growing season. Studies on genotype and water stress factors revealed, although there were significant differences between the genotypes based on the studied characters, water stress levels were not significantly different based on the short duration of the research. Species such as Haloxylon, which is not fast growing species, would not respond to the stress levels during a short period of time. The genotypes were significantly different based on leaf chlorophyll content. Correlation coefficients between the morphologic characteristics were also noticeable. Negative significant correlation between leaf chlorophyll with branch number and trunk diameter implied that desert plant species such as the species under study would take advantage of light color of less chlorophyll content to cope with high temperature and sun light of their habitats.
Mojtabah Akhavan Armaki; Hosein Azarnivand; Mohammad hasan Asareh; Ali ashraf Jafari; Ali Tavili
Volume 18, Issue 4 , September 2012, , Pages 558-568
Abstract
Environmental stress especially water deficiency (drought) is of the most important factors in arid and semi arid regions of Iran that hugely affects plant growth especially in germination and emergence stages. To find the effects of water stress on germination properties and early growth characteristics ...
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Environmental stress especially water deficiency (drought) is of the most important factors in arid and semi arid regions of Iran that hugely affects plant growth especially in germination and emergence stages. To find the effects of water stress on germination properties and early growth characteristics of three Bromus species (B. tomentellus, B. inermis, B. persicu), a Factorial experiment based on Completely Randomized Design with four replications was conducted. Water stress treatments included -3, -6 and -9 bars, also distilled water was considered as control. Germination percentage, root length, shoot length, seedling length, root to shoot ratio, seedling dry weight, seedling fresh weight, dry to fresh weight ratio, germination rate and seed vigor were examined as germination and early growth properties of understudied species. The results showed that increase of drought stress, especially when changing from -3 to -6 bars, significantly reduced all attributes. Seedling length and seed vigor showed more decrease. Among the species, B. tomentellus showed higher germination compared to the other species. It was cleared that -6 and -9 bars potentials could be considered as favorable water stress levels to evaluate the ability of the mentioned species for germinating under drought conditions.