جستجوی مقالات مرتبط با کلیدواژه « شبه میکوریز » در نشریات گروه « زراعت »

Agricultural soils in many parts of the world are slightly to moderately are contaminated by heavy metals elements. Among them, Pb has an effect on growth and metabolism of plants with a wide range of adverse effects like decrease in root elongation and biomass, accelerated leaf senescence, inhibition of chlorophyll biosynthesis and seed germination, interferes with nutrient uptake, influence the net photosynthetic rate and respiration and alternate permeability of cell membrane. So, the usage of a fast and safe method is necessary to remove pollutants with the lowest cost and impact on the environment. One of the best methods is phytoremediation that the Brassicaceae family plants such as canola (Brassica napus L.) have a special ability to refine contaminated soils due to their much biomass production. On the other hand, bioremediation is one of the methods that has been considered in recent years to remove contaminants. In this context, it is important to use a variety of microorganisms like algae, fungi and bacteria in order to improve phytoremediation efficiency. Therefore, the purpose of this research was to evaluate the effect of Piriformospora indica and Trichoderma longibrachiatum on improving the growth and some physiological traits of canola under lead stress.

This research was done as factorial layout based on a completely randomized design with three replications. Treatments were four levels of lead from lead nitrate source (0. 500, 1000 and 1500 mg kg-1 of soil) and three treatments of fungi (control, Piriformospora indica and Trichoderma longibrachiatum). After 60 days of (Hyola 401 cultivar) planting time, coinciding with the end of vegetative growth and before flowering, Vegetative and some physiological traits were measured. To quantify the effect of lead stress regression analysis and linear and segmental models were used.

The results showed that node and leaf number, stem diameter, leaf fresh weight and stem dry weight (between 20 and 58%) were reduced as linearly and segmental model where lead levels increased from zero to 1500 mg. Also, inoculation of Piriformospora and Trichoderma fungi increased stem diameter and dry weight. Using the mentioned fungi had a positive effect on vegetative traits at different levels of lead. Accordingly, plant height, leaf area, stem and shoot fresh weight and leaf and shoot dry weight reduced from 27, 74, 68, 65, 69 and 70% in control to 12, 44, 35, 36, 52 and 52% in symbiosis with Piriformospora and 31, 48, 58, 53, 52 and 53% after applying Trichoderma at in 1500 mg as compared to the zero levels, as well. Also, the electrolyte leakage rate showed an increasing trend with 0.000084 slope Up to 500 mg and then with a 0.0018 slope. But plant inoculation with Piriformospora and Trichoderma reduced the electrolyte leakage with about two percent. In addition, the interaction between lead and fungi was significant on SPAD reading, chlorophyll a+b, relative water content (RWC) of leaves and proline. SPAD reading and chlorophyll a+b declined from nearly 18 and 35% in non-inoculation treatment to about 7 and 27% in Piriformospora, and 13 and 5% in Trichoderma in 1500 mg as compared to the control, respectively. Among morphological and physiological traits, the highest correlation (r=0.80; P<0.01) was between leaf area and RWC.

In conclusion, results indicated that vegetative traits showed more sensitivity to lead toxicity. Among these traits, the highest sensitivity was recorded in stem and shoot dry weights. Inoculation of canola seed with Piriformospora and Trichoderma fungi ameliorated this sensitivity in some traits. Accordingly, it seems that these fungi can improve slightly the adverse effect of lead toxicity and increase canola tolerance to lead stress.

Medicinal plants are one of the main natural resources of Iran from ancient times. Perilla is an annual plant of the mint family Lamiaceae, native to east Asia and widely cultivated in India, China, Japan, Hong Kong, South and North Korea. Since, there was no study not only on adoptability of Perilla in Iran climate conditions but also on different fertilizer systems, this experiment was conducted in two experimental site (Mashhad Arde hal and Sen sen of Kashan). Experiment was conducted as split plot factorial based on a randomized complete block design with three replications at two experimental site in 2014. The main factor three chemical fertilizer levels (control, 50, 100, 200 kg/ha) and sub plots were different kinds of organic fertilizer (control, humic acid and compost application) and inoculation with Piriformospora indica (inoculation and uninoculation). Plant height, node number per plant, flower number per inflorescence, stem number per plant, leaf area index, plant yield, rosmarinic content and rosmarinic yield per area were studied. Statistical analysis of the data was performed using SAS software (version 9.1). Also, means comparison were compared by LSD test at 5% probability level. The results showed a significance different between two experimental locations so that Mashhad Arde hal showed better performance than Sen sen in terms of all studied traits. Among levels of chemical fertilizers, 50 and 100 kg/ha and between organic fertilizer, humic acid was recorded better result but biological fertilizers had no significance effect on studied traits, however, this fertilizer positive effects were obtained along with other fertilizer integrations. The highest plant yield (147.2 gr/m2) and rosmarinic acid yield per area (3.432 gr/m2) was achieved in 100 kg/ha at chemical fertilizer with humic acid and biological fertilizer application and the lowest plant yield (89.86 gr/m2) and rosmarinic acid yield per area (1.253 gr/m2) was observed in control. It seems that integrated application of chemical, organic and biological fertilizers improved soil physical and chemical properties and resulted in increase in availability of nutrients and ultimately the yield and quality of plants. Overall, Mashhad Arde hal due to good soil and climate charactristics was better for planting Perilla as compared to the Sen sen region. Also, integrated application of the studird fertilizers showed more positive effect on yield and quality of Perilla than individual application of those fertilizers

Environmental protection and safity of agricultural products are two major goals in sustainable agriculture. Hence, using plant growth promoting rhizobacteria may be effective to reduce chemical inputs. Therefore, a field split plot experiment based on a randomized complete block design (RCBD) was conducted at Ghaemshahr, Mazandaran Province in 2015. Treatments were consisted of three levels of phosphorus (P) fertilizer (0 or control, 50 and 100 kg.ha-1 as triple super phosphate) and coinoculation of rice seed and seedling with Trichoderma virens and Piriformospora indica fungi with four levels (uninoculated control, inoculation of seed or seedlings and seed seedlings inoculation). Results indicated that inoculation with these fungi significantly and positively affected the morpho-physiological traits and paddy yield of rice plant in all P levels. When, 0, 50 and 100 kg.ha-1 was applied, seed inoculation resulted in significant increase of panicle number per plant (33, 19 and 40 percent, respectively), filled seeds per plant (21, 45 and 58 percent, respectively), biological yield (31, 6 and 18 percent, respectively) and paddy yield (37, 48 and 43 percent, respectively). Also, fungi inoculation of rice seeds, seedlings and seeds seedlings improved paddy yield up to 48, 53 and 53 percent and 43, 44 and 15 percent when 50 and 100 kg.ha-1 of P was applied, respectively. In general, results indicated that all three methods of fungi inoculation had positive effect on rice plants under all P levels, which could be related to those fungi ability to improving the parameters under study such as panicle number per plant and biological yield. In conclusion, the positive effects of using both microorganisms and P were more pronounced than using P alone.