Showing 4 results for Symbiosis
R. Mohammadi, A. F. Mirlohi,
Volume 7, Issue 2 (7-2003)
Abstract
A symbiotic relationship exists between the endophytic fungi of the genus Neotyphodium and many cool-season grasses. Endophytes can alter the growth as well as morphological and physiological characteristics of the host plant, thereby influencing the persistence and survival rate of infected plants. This study was conducted to evaluate the effects of endophyte on phenotypic characteristics of Iranian tall fescue (Festuca arundinacea Schreb.) and meadow fescue (Festuca pratensis Huds.). The experiment was set up as a completely randomized design with three replications in a factorial arrangement. The first factor was the two plant accessions and the secondary factor was the endophyte-infected and noninfected plants. The results showed that most of phenotypic characteristics significantly altered as a result of endophyte infection in both tall fescue and meadow fescue plants. Results of analysis of variance showed that the influence of endophyte fungus was positive and significant on tiller number, herbage yield, dry crown weight, dry root weight per plant, and crown depth. Also between plant accessions, there were significant differences for dry herbage yield, crown weight, dry root weight per plant, crown depth, and dry matter percentage. Plant by endophyte interaction was highly significant for crown depth and dry root weight per plant. Therefore, eudophytic fungi can be used to improve phenotypic characteristics in these plants.
M. Bagheri Mofidi, M. Bahar, H. Shariatmadari, M. R. Khajehpour,
Volume 10, Issue 2 (7-2006)
Abstract
To investigate drought tolerant isolates of rhizobial symbioant of lentil (Lens culinaris L.), 12 soil samples were collected from cultivated and non-cultivated area of Golestan, Chaharmahal-O-Bakhtiari and Isfahan provinces. Local cultivars of lentil including Binam Dorosht, Ghazvini and Faridani were planted in each soil sample. After 10 weeks, a total of 324 rhizobial isolates were recovered from root nodules of the lentil plants. Evaluation of the ability of the isolates to grow at different concentration of salt showed that all isolates grew normally on 200 mM NaCl and only 20% was determined as salt tolerant isolats(>400mM). Among the isolates RL249 was classified as superior salt tolerant strain due to growing on 600 mM salt. The drought tolerance of the isolates was also examined, using PEG6000. In general, the salt tolerant isolates were also drought tolerant, however their tolerance to salinity and drought is not related to their geographical origin. In a randomized split factorial design with three replications, the effectiveness of tolerant isolates(RL249 and RL211) and a sensitive strain (RL 77) was compared on two cultivars of lentil (Binam Dorosht and Faridani) under water stress treatments with the consumptions of 50, 75,90 and 98% of soil available water. Although nodulation rate was reduced in both cultivars as the consequence of drought stresses, plants of Binam Dorosht cultivar showed high nodulation rate due to the increased fresh weight of the roots. Despite the fact that RL249 was identified as a superior nodulating and salt/drought isolate, however nodulation efficiency was decreased significantly under water stress treatments with more than 50 % of soil available water.
F. Aghababaei, F. Raiesi,
Volume 15, Issue 56 (7-2011)
Abstract
The positive and beneficial effects of mycorrhizal symbiosis on the growth of various plants have already been documented. Most arable crops can mutually establish symbiosis with endo-mycorrhizal fungi, however, mycorrhizal associations with almond (prunus amygdalus), particularly in calcareous soils of arid and semi-arid regions, have not been studied. Thus, to realize the symbiotic association between mycorrhiza fungi and economically important native almond genotypes in Chaharmahal va Bakhtiary province, an experiment consisting of a randomized complete factorial design with three factors: almond genotypes (Mamaei, Rabee, Talkh, Sefid), soil phosphorus levels (0 and 150 kg P ha-1) and mycorrhizal treatments (almond inoculated with Glomus intraradices, Glomus mosseae and without inoculation) with three replications was conducted under greenhouse conditions by 4 months. Results showed that physiological traits including chlorophyll concentration, net photosynthetic rate and water use efficiency, were significantly increased for 20%, 300% and 300%, respectively in mycorrhizal almond plants, while transpiration rate was decreased
(8-10%). Although the genotype of almond and soil P were dependent on these factors, mycorrhiza species had the same effects. Increased available P in the soil enhanced the growth in all treatments and photosynthesis of nonmycorrhizal almonds.
S. Ghasemi Pirbaloti, S. Soodaee Moshaee,
Volume 28, Issue 1 (5-2024)
Abstract
Since the long-term sustainability of garden ecosystems is dependent on maintaining the soil quality, knowing the condition of the soils and investigating the effects of the activities on the soil properties is very important and effective in ecosystem management. To investigate the soil quality index of almond (Prunus dulcis) orchards under different managed methods in ChaharMahal va Bakhtiari province, soil samples were collected from three points in each orchard and finally classified into 6 groups (Saman, Ben, Shahrekord, Kiar, Ardel, and Farsan). To determine the soil quality index, soil characteristics including pH, EC, total and water-soluble organic carbon, basal and substrate-derived respiration, rhizosphere microbial population, and available soil P and K were analyzed. The results showed that almond orchard management in different regions affected the soil characteristics and the processes evaluated in this study. The monitoring of soil properties showed that pH 7.05 - 8.48, EC 0.23 - 2.91 dS/m, microbial respiration 0.44 - 8.57 mg CO2.100 g-1.day-1, organic carbon 2.09 - 44.79 g/kg, available phosphorus 1.5 - 122.3 mg/kg, and available potassium were between 91.2 - 3038 mg/kg. Soil quality index components including chemical components, microbial activity, microbial population, and soil organic carbon were determined. The contribution of soil salinity to soil quality obtained using factorial analysis was the highest (31%), followed by microbial carbon mineralization coefficient (27%), rhizosphere microbial population (24%), and water-soluble organic carbon (18%). The soil quality index values for Saman, Ben, Shahrekord, Kiar, Ardal, and Farsan almond orchards were 0.46, 0.40, 0.51, 0.67, 0.54, and 0.37, respectively. These values showed that the evaluated soils are suitable for almond production in Shahrekord, Kiar, and Ardal, and for Saman, Ben, and Farsan, there is a need for serious management measures to improve soil quality and increase the sustainability of these agricultural ecosystems.
