جستجوی مقالات مرتبط با کلیدواژه « root colonization » در نشریات گروه « باغبانی »

Since Iran is one of the arid and semi-arid regions of the world and due to the great importance of water in agriculture, it is very important to conduct research to improve drought stress in order to produce more quality products. In this regard, this study was conducted to investigate the effect of mycorrhiza species on some morphological and physiological characteristics of peach seedlings under drought stress. Arbuscular mycorrhizal fungi coexist with the roots of various plants and have a broad effect on their growth. These fungus are effective in the initial establishment of the plant under drought conditions. Arbuscular mycorrhizal fungi increases plant resistance to dehydration by increasing growth and uptake of nutrients, especially phosphorus.

In order to investigate the effect of three species of Arbuscular mycorrhizal fungi on some vegetative characteristics and phosphorus absorption of peach seedlings under drought stress conditions, a factorial experiment was conducted based on a randomized complete block design with four replications. The experimental factors included: drought stress at four levels (100, 80, 60 and 40 percent of field capacity) and the second factor application of mycorrhizal fungus at four levels: application of three species of mycorrhiza fungi and three species of fungi, each in three concentration (75, 100, 125 g in a pot) with chemical fertilizer (100 g triple super phosphate for each pot) and fertilizer (without mycorrhiza) and control (without fertilizer and mycorrhiza). The measurements were comprised root traits, stem diameter, vegetative growth of branches, leaf area index, vegetation index, relative leaf water content, chlorophyll fluorescence, leaf electrolyte leakage, leaf phosphorus and colonization root percent.

Result showed that application of mycorrhizal fungi seems to be effective in reducing the effects of dehydration stress. The use of these fungi had a positive effect on reducing leaf electrolyte leakage under severe dehydration. According to the results obtained in this experiment, the highest efficiency in drought stress conditions was observed in G. mosseae and G. intraradices. Under drought stress conditions, the lowest values of root volume, greenness index, chlorophyll fluorescence, leaf electrolyte leakage, root colonization and leaf phosphorus content were observed. With increasing of drought stress, all of the mentioned traits reduced and mycorrhiza fungi had a positive significant effect on all studied traits. In this study, it was found that with increasing stress intensity, the traits were negatively affected and led to irreparable damage to the product. Therefore, it is expected that by preventing or minimizing the effects of stress, an effective step was taken to increase performance. The significant decrease in root colonization with increasing stress is probably due to the decrease in the growth of hyphae. The most important step after spore germination is the growth of hyphae resulting from germination, which plays an essential role in root colonization. Apparently, hyphae growth is more affected by osmotic potential than spore growth. The results obtained from this research showed that the roots of peach seedlings have significant symbiosis potential with arbuscular mycorrhizal fungi (Peymaneh & Zarei, 2013). According to Miyashita et al. (2005) Leaf photosynthesis activity can be used as a useful tool for classification of drought tolerant plants. Sajjadinia et al. (2010) regarding the relative water content and photosynthesis of several pistachio cultivars reported high correlation and high diversity in different stages and cultivars and stated that the decrease in relative water content strongly reduces transpiration, stomatal conductance and photosynthesis, which our results are consistent. With the escalation of tension, the greenness index also decreased; So that in the conditions of severe stress (40% of crop capacity), the amount of greenness index reached the lowest value. In the conditions of severe stress due to interruption of continuous irrigation, the plants entered from the stage of mild stress to the stage of severe dry stress, which seems that under these conditions, the decrease in the concentration of chlorophyll, in addition to the decrease in the amount of synthesis, is caused by the decomposition of chlorophyll due to the increase in the amount chlorophyllase, peroxidase and phenolic compounds. According to Schutz and Fangmier (2001), the decrease in the amount of chlorophyll in stress conditions is related to the increase in the production of oxygen radicals in the cell. These free radicals cause peroxidation and as a result the decomposition of this pigment. The greenness index is considered one of the most important growth parameters, which is reduced by drought stress conditions, and the results indicate that the treatment of mycorrhizal fungi in all three types of inoculated mushrooms has improved the greenness index and the adverse effects It has removed the drought stress to a great extent (Figure 6), which can be attributed to the improvement of water and food absorption by mycorrhizal roots (Larsson et al., 2008).

 In general, this study showed that the best treatment related to the mycorrizha fungi was mosseae, which had the most effect on reducing the negative effects of stress

Organic fertilizers and symbiotic fungi are very important in agriculture because of their special role as a link between soil and plant. Currently, large parts of the country's pistachio orchards are facing water and soil salinity crisis. In this study, the effect of processed pistachio waste compost at three levels (0, 10 and 15 kg per seedling) and mycorrhizal fungi at three levels (0, 100 and 200 g soil containing fungal spores per seedling) belonging to four species (Funneliformis mosseae, Rhizophahus intraradices, Glomus iranicus, Rhizophahus irregularis) on vegetative growth and leaf nutrients concentration of two pistachio cultivars of Akbari and Badami Zarand, with three replications (each replicate consisting of four seedlings) were investigated. This experiment was carried out as a factorial split-plot in randomized complete block design (RCBD) for two years (2017 and 2019) in the saline-sodic soil and water condition. The results showed that 15 kg of pistachio waste compost increased the concentrations of nitrogen, iron, zinc and manganese elements in the leaves by 4, 9.7, 8 and 12.1% compared to control, respectively. Also, the height, width and leaf area of seedling leaves increased by 9.6%, 11.8% and 2.8%, respectively, by applying of 15 kg of pistachio waste compost compared to the control. The maximum concentration of leaf iron (702.2 mg kg-1) was observed in the treatment of 200 g of fungi. In the treatment of 100 g of mycorrhiza, the concentrations of manganese, leaf area and height were the highest with 64.8 mg kg-1, 415.3 cm2 and 44.9 cm, respectively. The root colonization percentages were 35.1 and 27.2 in Akbari and Badami Zarand cultivars, respectively. Overall, 15 kg of pistachio waste compost along with 100 grams of mycorrhizal fungi can result in proper vegetative growth of pistachio seedlings the saline water and soil conditions.

In order to investigate the effects of humic acid and mycorrhiza on gerbera cv. Dune, an experiment was performed as a completely randomized design with two factors and three replications in hydroponic conditions. First factor included humic acid at 4 concentrations (0, 500, 1000, and 2000 mg L-1 as media drench). The second factor contained two levels of mycorrhizal fungi (with and without mycorrhiza at root zone). Attributes such as leaf number, rosette diameter, root fresh and dry weight, flower diameter, flower stalk diameter and number, time from bud emergence to anthesis, total phenol content, colonization percent and the activity of ascorbate peroxidase and hydrogen peroxide were measured. The results showed that humic acid and mycorrhizal fungi treatments led to increase in the leaf number, rosette diameter, fresh and dry weight of roots and antioxidant enzymes activity and decreased the time from bud emergence to anthesis comparing untreated plants. Phenol content was significantly increased compared to control plants by application of 1000 and 2000 mg L-1 of humic acid plus mycorrhizal fungi. The combined use of humic acid and mycorrhiza was effective to improve some morphological and physiological properties of gerbera and the concentration of 1000 mg L-1 humic acid plus mycorrhiza application were the most effective treatment.

This study was carried out to isolate and identify plant growth-promoting rhizobacteria (PGPR) from saline soils and to evaluate the effect of isolated rhizobacteria, as well as symbiotic and endophytic fungi on the concentration of some nutrient elements in wheat plants under salinity stress in greenhouse conditions. Factors included microbial treatments (rhizobacteria, mycorrhizal fungi, endophytic fungus, and control) and salinity levels (no salinity, 8 and 14 dS m-1). At the end of the growth period, the concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), iron (Fe), zinc (Zn) and manganese (Mn) in the shoot of the wheat plant, as well as the percentage of root colonization were measured. Based on growth-promoting trails, three isolates among the ten purified rhizobacteria were selected for phenotypic and molecular identification. Two identified isolates belonged to Pseudomonas genus (Pseudomonas aeruginosa Ur743 and Pseudomonas fluorescens Ur745), and the last one was Stenotrophomonas maltophilia Ur840. When the concentrations of nutrient elements were at the non-salinity level, mycorrhizal fungi were better than other microbial treatments in terms of absorbing P, Fe, and Mn, However, at the highest salinity level (i.e., 14 dS m-1), rhizobacteria significantly improved concentrations of N, P, Fe, and Mn in the plant shoot, compared to the control. Besides, the PGP bacteria increased the concentrations of K and Zn, as well as K:Na ratio by 1.99, 1.71, and 1.37 times, respectively, as compared to the control. In general, native microorganisms isolated from saline soil, as compared to other microorganisms in this study, improved the nutrient uptake and increased the wheat plant biomass under salinity stress.

High temperature is the most important limiting factor for plant growth in many regions. This problem is very serious because of a heading global warming phenomenon. So study of high temperature effects on different cultivars and species and finding out solution to improve plant tolerance is necessary. In this research, effect of mycorrhizalarboscular fungus on some physiological traits of grapevine (Perllete cultivar ) subjected to three temperature (25ºC, 40ºC, 45ºC) was evaluated. The experiment was conducted as a factorial experiment based on completely randomized desing with four replications. The results indicated that photosystem II photochemical efficiency and chlorophyll index were reduced in vines subjected to 45ºC without mycorrhizal fungus inoculation. Whereas this parameters were not significantly affected in vines inoculated by this fungus. In general, in ‘Perllete’ grapevine, inoculation by mycorrhizal had significant effect on tolerance improvrment to high temperature stress.

Effects of arbuscular mycorrhizal fungus (Glomus mossea CA) and plant growth promoting rhizobacteria (PGPR) of Bacillus pantea and Psedomonas putida were evaluated on growth parameters of Osteospermum (Osteospermum hybrida ‘Passion Mix’) under different watering conditions (field capacity, two and one third of field capacity). Arbuscular mycorrhizal fungus (AMF) and PGPR were applied as single or mixed. A factorial trial based on randomized complete block design with 3 replications per treatment and 4 replicates was carried out under greenhouse conditions. Root colonization, growth parameters and P concentration in plant was measured. Results showed that PGPR and mycorrhizal inoculated plants had better nutritional conditions than that of non-inoculated plants. Moreover, there was a synergetic effect between AMF and PGPR in this study. PGPR were as much effective as AMF on alleviating the negative impacts of drought stress. According to the results, applied microorganisms were more effective on improving the growth parameters at 70% of field capacity, while at 40% of field capacity; their effective role was reduced, although the plants were persistent, yet. Results revealed exploitation of AMF and PGPR and administering an optimized irrigation regime can be effective on improving yield of this plant.

Iran is the largest producer of saffron (Crocus sativus) in the world. More than 80% of higher plant species have a mutual relationship with mycorrhizal fungi, which enhances the plant growth and its productivity. With identification of native arbuscular mycorrhizal fungi and their application, it could be possible to expand saffron cultivated area and increase the performance of arable lands. In the present study, native AMF species associated with saffron roots in Khorasan Razavi and Southern Khorasan provinces (north east of Iran), and nine species of arbuscular mycorrhizal fungi, viz., Claroideoglomus claroideum, C. etunicatum, Corymbiglomus tortuosum, Funneliformis caledonius, F. geosporum, F. mosseae,Paraglomus albidum, Rhizophagus aggregatus and R. manihotis were identified which are all newly recorded for saffron mycoflora of Iran. Rhizophagus manihotis and F. mosseae were the most frequent species in all soil samples. Although, the maximum plants and fungal growth and root colonization usually take place in spring, but in case of saffron, results showed that, this happened in autumn which indicates, the fungus has adapted itself to host plant life cycle. On the other hand, correlation coefficient between spore population and root colonization was very low for Torbat specimens, which could be related to other factors e.g. environmental and geographical conditions.

Arbuscular mycorrhizal symbiosis is formed by approximately 80% of the vascular plant species in all terrestrial biomes. Using soil microbial potential including arbuscular mycorrhizal fungi (AMF) has been widely considered for improving plant growth, yield and nutrition. Medicinal herbs are known as sources of phyto chemicals or active compounds that are widely sought worldwide for their natural properties. Members of the Lamiaceae family have been used since ancient times as sources of spices and flavorings and for their pharmaceutical properties. Peppermint (Mentha piperita) has a long tradition of medicinal use, with archaeological evidence placing its use at least as far back as ten thousand years ago. Essential oils - are volatile, lipophilic mixtures of secondary plant compounds, mostly consisting of monoterpenes, sesquiterpenes and phenylproponoids.Arbuscularmycorrhizal fungi with colonizing plant roots improve nutrient uptake as well as improving essential oil yield of medicinal plants by increasing plant biomass. The aim of the present study was to evaluate the effect of AMF inoculation on essential oil content and some growth parameters of peppermint (Mentha piperita) plant under glasshouse condition.
This study was performed on a loamy sand soil. The samples were air-dried, sieved (