Percentage Of Root Colonization Research Articles

Inoculation of Native Arbuscular Mycorrhizae and Bacillus subtilis Can Improve Growth in Vegetable Crops.

Arbuscular mycorrhizal fungi (AMF) and some rhizobacteria are known as plant growth-promoting microorganism (PGPM) as they play significant roles in improving soil fertility structure, plant nutrition, growth, and health. However, little is known about the PGPM potential of AMF and rhizobacteria native to the Rift Valley and highland regions of Ethiopia. Hence, this study aimed to investigate the PGPM effect of single and co-inoculation of AMF and the Bacillus subtilis ALCR46 strain, on tomato (Lycopersicum esculentum L.), onion (Allium cepa L.), and squash (Cucurbita pepo L.) plants. The experimental setup was a randomized complete block design with three replications of the following treatments: (i) inoculation with a consortium of AMF, (ii) co-inoculation with a consortium of AMF and the Bacillus subtilis, (iii) inoculation with Rhizophagus clarus, (iv) co-inoculation with R. clarus and B. subtilis, (v) inoculation with B. subtilis, (vi) plants without inoculation (negative control), and (vii) plants treated with chemical fertilizer (positive control). Plants were maintained in a greenhouse for 60 days, and after harvest, plant growth parameters, percentage of AMF root colonization, and spore number were analyzed. The result shows that the growth of crops significantly increased by co-inoculation with the consortium of AMF and B. subtilis. AMF spore density and root colonization rate were also increased in co-inoculated plants. Highest root colonization, spore number, and mycorrhizal dependency were observed in A. cepa. Our results suggest that there is a synergistic effect between the AMF and B. subtilis ALCR46, and between AMF inoculants. However, the application of present findings under field conditions is required to be confirmed by further studies.

Effects of Different Vesicular - arbuscular Mycorrhizal (VAM) Fungi on the Seedling Growth of Tecomella undulata

Tecomella undulata (Sm.) Seem. (family Bignoniaceae) is a tree found in desert parts of India, and Arabia. The cultivation of high-quality seedlings is vital for establishing a successful plantation and the contribution of arbuscular mycorrhizal fungi (AMF) in the soil plays a vital role in the nursery phase. A study conducted during the periods of 2021-22 and 2022-23 scrutinised the effect of four distinct species of Glomus spp. (G. mosseae, G. intraradices, G. fasciculatum and Glomus hoi) on Tecomella undulata seedlings in AMF-inoculated soil. The inoculation involved applying of 400-500 sporocarps/kg of soil during sowing and the evaluation encompassed growth and survival parameters. Results revealed that among the 4 Glomus species, soil inoculated with Glomus fasiculatum at 180 days after sowing, significantly increased the root colonization percentage with (50.69 and 46.71 %) in year (2021-22) and (2022-23) compared to the uninoculated control. Additionally, seedlings exhibited significantly higher no. of spores per 100g of soil, when treated with (Glomus fasiculatum) inoculated soil, which was statistically at par with soil inoculated with (Glomus intraradices) at (103.67 and 98.65). During both the experimental year, in terms of germination percentage, root length and root: shoot ratio were found non- significantly with (44.45 %), root length at 360 DAS, (26.67 and 25.74) respectively, root shoot ratio at 360 days after sowing. While, plant survival percentage (30.63 and 25.41%) at 90 DAS. Whereas, at 360 DAS, collar diameter (6.14 and 10.07 mm), shoot length (33.36 and 32.19 cm), plant biomass (8.31 and 8.05 g), leaf area (196.29 and 185.46 cm 2) was observed significantly higher in treatment T3 (Glomus fasiculatum) which was statistically at par with treatment T1 (G. intraradices). It is concluded from study that Glomus fasiculatum were found best for growth and survival of seedlings followed by Glomus intraradices as compare to control.

Identification and molecular detection of Arbuscular Mycorrhizal Fungi colonized naturally in citrus roots in nurseries

Abstract. Sariasih Y, Subandiyah S, Widyaningsih S, Khurshid T, Mo J. 2023. Identification and molecular detection of Arbuscular Mycorrhizal Fungi colonized naturally in citrus roots in nurseries. Biodiversitas 24: 6283-6290. Citrus plants heavily depend on arbuscular mycorrhizal (AMF), a diverse collection of fungi. The objective of this study was to investigate the root colonization, spore density, spore morphology, and molecular identification of AMF colonizing four citrus root species: Japansche Citroen (Citrus limonia Osbeck.), Cleopatra mandarin (Citrus reshni), Salam (Fortunella japonica cv. "Salam"), and Rough Lemon (Citrus jambhiri). AMF was identified by observing spore morphology and molecular PCR methods using the group-specific primers of Glomeromycota, AML1/AML2. Based on the morphological observation, C. limonia was found with the highest root colonization (50%), followed by F. japonica cv Salam (44%), C. reshni (38%), and C. jambhiri (36%). The highest number of AMF spores was found on C. jambhiri rhizosphere soil, which had 1,379 spores/100 g of soil with the lowest percentage of root colonization. Three mycorrhizal genera were identified, with Funneliformis (syn. Glomus) being the most dominant genus, followed by Gigaspora and Acaulospora. The sequence of PCR products confirmed the highest similarity range from 83.7-99.0% to that of Funneliformis, followed by Acaulospora at a similarity range from 83.3-99.0% and found on all of the citrus species. The similarity sequence of the PCR products to that of Gigaspora ranged between 83.3-95.0%, which was only found on C. reshni and C. jambhiri.

Farmyard manure and arbuscular mycorrhiza fungi inoculation enhanced growth and fruit fibre productivity of Calotropis procera in semi-arid eastern Kenya

A greenhouse experiment was conducted at the South Eastern Kenya University (SEKU) to determine the effects of farmyard manure (FYM) and arbuscular mycorrhiza fungi (AMF) inoculation on growth, vigor, shoot nutrient uptake (SNU) and AMF root colonization percentage (RC%) of potted Calotropis procera (Calotropis) seedlings. A field trial was laid out to determine the effects of the treatments on growth and fruit fibre productivity of the transplanted seedlings. The experiments were laid out in a split-split-plot design with a 2*2*2 factorial arrangement and 3 replications. The main plot factor constituted 2 Kenyan Calotropis provenances, Kibwezi and Tharaka. The sub-plot factor comprised of FYM and without FYM application while the sub-sub-plot factor involved inoculation with mixed strains of commercial AMF and without inoculation. Farmyard manure (FYM) and the integration of FYM and AMF inoculation (FYM*AMF) significantly improved Calotropis seedlings’ growth, vigor, SNU and AMF RC% in the greenhouse. However, FYM*AMF was comparatively superior to solely FYM and AMF. There were positive correlations of AMF RC% with growth, shoot dry weight (SDW) and SNU of the seedlings at the end of the greenhouse experiment. Under field conditions, FYM and FYM*AMF significantly enhanced growth and fruit fibre productivity of Calotropis plants than the controls, barring a few cases. The study recommends the use of FYM and FYM*AMF in Calotropis seedlings’ production in the drylands of Kenya. Future research should investigate the persistence of the introduced commercial AMF strains in the soil using molecular techniques.

Exploring the interplay between Arbuscular Mycorrhizal Fungi and weed dynamics in agricultural ecosystems.

Weeds are responsible for major crop losses worldwide but can provide beneficial agroecosystem services. The present study aimed to study the association of arbuscular mycorrhizal fungi in common weeds found in agro-ecosystem. Around 19 weeds were collected from various locations of eastern dry zone of Karnataka. The mycorrhizal association was determined by root staining technique. Of the 18 weed samples, AM fungal association was found in 17 weed species and the percent root colonization ranged from 10-68 %. Highest root colonization was found in weeds belongs Graminaceae family. The result of the study concludes that, AM fungi colonizes the weeds and they may act as host during the off seasons.

Distribution of Arbuscular Mycorrhiza Fungi (AM Fungi) in different plants within tailings deposition areas of Freeport Indonesia, Timika, Central Papua, Indonesia

Abstract. Djuuna IAF, May NL, Kubangun SH, Massora M, Aibini SW. 2023. Distribution of Arbuscular Mycorrhiza Fungi (AM Fungi) in different plants within tailings deposition areas of Freeport Indonesia, Timika, Central Papua, Indonesia. Biodiversitas 24: 4515-4522. This study investigated the presence of Arbuscular Mycorrhiza Fungi (AM Fungi) in various vegetation types within tailings deposition areas in Freeport Timika, Papua. Soil and root samples were collected from 41 sampling locations, representing 28 types of vegetation growing in these areas. AM Fungi spores were extracted using the wet sieving technique, while root samples were cleaned, stained, and analyzed for the percentage of root infection using the gridlines method. Some soil characteristics were also analyzed, including pH (H2O), moisture content, organic carbon (C), Total nitrogen (N) and phosphorus (P), and soil texture. The study showed low total soil N and P levels, with organic C ranging from low to high and a pH range from 6 to 6.7. The spore number ranged from 2 to 20 spores/10 g soil, and the percentage of root colonization varied from 17 to 89.5%. The highest number of spores (20 spores/10 g soil) was found in the rhizosphere of Homalanthus sp. and Polyalthia glauca, while the highest percentage of root colonization (89.5%) was observed under Pandanus sp. at Upper ADA. Notably, the highest number of spores did not correspond to the highest percentage of infected roots. Additionally, four genera of AM Fungi, namely Glomus, Acaulospora, Scuttelospora and Gigaspora, were found to thrive in tailings areas and have the potential to be developed as biofertilizers for tailings rehabilitation programs.

Arbuscular mycorrhizal characterization associated with Uncaria guianensis and Uncaria tomentosa in Amazonian soils

There are some plant species with cultural and economic importance in the Amazon, such as Uncaria guianensis and U. tomentosa, both commonly named “cat's claw”. Since these species grow in soils with low levels of organic matter and nutrients, both depend on arbuscular mycorrhizae to grow. The information about arbuscular mycorrhizal fungi communities for U. tomentosa is limited and there is no current research on U. guianensis. Therefore, this research provides additional information on the arbuscular mycorrhizal fungi communities associated with Uncaria species in Amazonian soils. Both the percentage of root colonization and the influence of the edaphic composition in the two species were determined. Also, the richness and diversity of arbuscular mycorrhizal fungi were assessed using the spore isolation method and also, through the molecular analysis of virtual taxa. In addition, the difference between the soils was analyzed. Although U. guianensis grows in both Oxisols and Alluvial Entisols and U. tomentosa is restricted to Oxisols, sporulation of AM and root colonization does not respond significantly to variations in soil chemical properties. Additionally, 72 virtual taxa were identified for Uncaria species (53 U. tomentosa and 19 U. guianensis) and the relative abundance of arbuscular mycorrhizal fungi was higher in roots of Uncaria species than in soils. The arbuscular mycorrhizal fungi community that colonizes the roots of Uncaria species indicates that these species behave as wild species; therefore, the ex-situ propagation of the species in agricultural systems could be less successful than forest enrichment.

The Effect of Pre-sowing Treatments with Glomus mosseae and GA3 on the Leaves Physiology of Melia azedarach Seedling

Melia azedarach, a versatile tree belonging to the Meliaceae family, presents a significant challenge in achieving successful seed germination for forest plantations. The robust nature of Melia azedarach seeds necessitates pre-treatments to overcome physical barriers and enhance water absorption. Natural ecosystems often benefit from the symbiotic relationship between Arbuscular mycorrhizal (AM) fungi and plant roots, which promotes survival and growth. This study examined the impact of Glomus mosseae-inoculated soil on Melia azedarach seeds treated with pre-sowing techniques at the Nursery of the Forestry Department, CCSHAU, Hisar in 2019. Glomus mosseae was sown at a rate of 400–500 sporocarps per kg of soil, and its influence was evaluated in terms of physiological parameters, survival rate, root colonization percentage, and sporocarp count. Each replication of the experiment involved 250 seedlings and was repeated five times. Results demonstrated that soils inoculated with Glomus mosseae and treated with gibberellic acid at 200 ppm for 24 hours prior to sowing exhibited significantly higher physiological parameters (chlorophyll and carotenoid content, photosynthesis rate, transpiration rate, and stomatal conductance), survival percentage, root colonization percentage, and sporocarp count (per 100 g of soil). Therefore, the combined use of Glomus mosseae and gibberellic acid at 200 ppm for 24 hours is recommended to enhance physiological growth and plant survival in Melia azedarach.

Seaweed extract and arbuscular mycorrhiza co-application affect the growth responses and essential oil composition of Foeniculum vulgare L.

The influence of arbuscular mycorrhiza fungi (AMF) inoculation, seaweed extract (SWE) foliar use, and their co-applications were evaluated on the growth-associated traits, antioxidant potential, essential oil profile, and the nutrients content of fennel plants. A factorial experiment was conducted as a completely randomized design with two factors and four replications in the greenhouse. The factors were: AMF inoculation (not inoculated and inoculated with 5gkg-1) and SWE foliar application (0, 0.5, 1.5, or 3gL-1). The highest root colonization percentage was recorded in plants treated with AMF + 3gL-1 of SWE. The top recorded plant height, leaf number, leaf dry weight, biomass, thousand seed weight (TSW), total soluble proteins and total soluble carbohydrates content, antioxidant activity, and essential oil content belonged to AMF + 3gL-1 of SWE. Furthermore, the co-application of AMF + SWE resulted in a considerable enhancement of the photosynthetic pigments content and, in N, P, K, Fe, Zn, and Mn contents in the shoots and roots. The GC-FID and GC-MS analysis revealed that (E)-anethole (73.28-76.18%), fenchone (5.94-8.26%), limonene (4.64-6.58%), methyl chavicol (2.91-3.18%), and (Z)-β-ocimene (1.36-2.01%) were the principal essential oil constituents. The top (E)-anethole and fenchone contents were obtained by AMF + SWE. Altogether, the simultaneous application of AMF and SWE could be introduced as an environment-friendly strategy to reach reliable growth responses, especially in fennel plants' enriched with some precious essential oil constituents.

Combined Phosphorus and Water stress Conditions Induce Negative Mycorrhizal Response in Maize (Zea mays L.)

Arbuscular mycorrhizal fungi (AMF) confer both positive and negative effects on the plant symbionts, depending on the prevailing growth condition. We investigated the effect of concurrent variations in phosphorus and soil moisture on percentage root colonization (%RC), mycorrhizal growth response (MGR) and drought response index (DRI) of SAMMAZ-16 maize variety in timescale. The experimental factors were AMF inoculation (addition or no addition), P2O5 applications (30, 60 or 90 kg ha-1) and water regimes (100% and 50% of the soil’s field capacity introduced after 4WAS). The result shows that the overall %RC was 62.22% at 8 weeks after sowing (WAS) and 71.33% at 12 WAS. With 30 and 60 kg P2O5 ha-1 application a rate, %RC was significantly higher at 12 WAS than that of similar application rates at 8 WAS. However, %RC was not different between 8 WAS and 12 WAS in 90 kg P2O5 ha-1 application. AMF inoculation tended to equilibrate the shoot growth of the inoculated plants to that of non- inoculated plants that received 50% higher doses of P2O5 under amply watered conditions. Increasing phosphorus application progressively alleviated the negative mycorrhizal response of the plants at the early stage of growth (week 4) and in 50% FC category at the other sampling times. Higher doses of P2O5 application improved the DRI of the maize in both samplings but the trend was more consistent in AMF-inoculated plants. We conclude that AMF inoculation would be detrimental to the growth of SAMMAZ-16 when there is combined phosphorus and water stress factors

Biodiversity of Vesicular-Arbuscular Mycorrhiza in the rhizosphere of some medicinal plants of Kurukshetra University

The Vesicular-Arbuscular Mycorrhiza (VAM) plays an integral role in agricultural sustainability by increasing the growth and productivity of plants. During the present study, the diversity of VAM fungi was studied in the rhizosphere of 17 medicinal plant species and the parameters, percent root colonization, spore number and diversity of VAM spores associated with the rhizosphere of medicinal plants were calculated. All the selected species were found to be mycorrhizal with varying degrees of species richness. A total of 62 morphotypes belonging to 4 genera, Glomus, Acaulospora, Sclerocystis and Gigaspora were found along with 2 unidentified genera. The spore number varied from 28.6 ± 9.864 to 326 ± 78.747 spores per 50g of soil. Percent root colonization ranged from 16.6% to 84.3% with maximum colonization in Barleria cristata L. and minimum colonization in Annona squamosa L. The genus Glomus was dominant with 32 species followed by Acaulospora (12), Gigaspora (9) and Sclerocystis (8).

Abundance and distribution of arbuscular mycorrhizal fungi associated with oil-yielding plants.

Due to their role in nutrient transmission, arbuscular mycorrhizal fungi (AMF) are widespread plant root symbionts. They may improve plant production by altering plant community structure and function. Therefore, a study was conducted in the state of Haryana to analyze the distribution pattern, diversity, and association of different AMF species with oil-yielding plants. The results of the study revealed the percentage of root colonization, sporulation, and diversity of fungal species associated with the selected 30 oil-yielding plants. The percentage root colonization ranged from 0% to 100%, the highest in Helianthus annuus (100.00 ± 0.00) and Zea mays (100.00 ± 0.00) and the least in Citrus aurantium (11.87 ± 1.43). At the same time, there was no root colonization in the Brassicaceae family. The number of AMF spores present in 50 g of soil samples varied from 17.41 ± 5.28 to 497.2 ± 8.38, with maximum spore population in Glycine max (497.2 ± 8.38) and minimum in Brassica napus (17.41 ± 5.28). Besides, the presence of several species of different genera of AMF was reported in all the studied oil-yielding plants, that is, 60 AMF belonging to six genera viz. Acaulospora, Entrophospora, Glomus, Gigaspora, Sclerocystis, and Scutellospora were observed. Overall, this study will promote AMF usage in oil-yielding plants.

Soil properties and growth of yellow bell pepper (Capsicum annum) as influenced by compost and arbuscular mycorrhizal fungi

Compost is an inexpensive agricultural waste which improves soil health and quality. The experiment was carried out to assess the influence of compost and mycorrhizal inoculation (Glomus mosseae) on soil properties and growth of yellow bell pepper in pots under screen house conditions, in a completely randomized design with three replicates. The treatments included mycorrhizal inoculation only (C0M1), compost at 20 t ha-1 only (C1M0), compost at 30 t ha-1 only (C2M0), compost and mycorrhizal inoculation at 20 t ha-1 (C1M1), compost and mycorrhizal inoculation at 30 t ha-1 (C2M1) and control (no amendment / uninoculated). Compost and mycorrhizal inoculation (C1M1 and C2M1) significantly improved soil N, P and K compared to control. Inoculation with mycorrhizal only (C0M1) increased uptake of N, P, K, Ca and Mg compared to uninoculated. Co-utilization of compost and mycorrhizal inoculation significantly increased root and shoot dry biomass compared to uninoculated. The highest fruit yield was obtained at C2M1 followed by C1M1 in comparison to compost application only. Treatment C2M1 recorded the highest prevalence of percent root colonization. This suggests that compost and Glomus mossea could be considered to have a sustainable potential for better growth and yield performance in the production of yellow bell pepper in an Alfisol.

Seasonal Variation of Mycorrhizal Association (Root Colonization and Spore Density) in Selected Industrial Sites in Kota District of Rajasthan, India

This paper aims to assess the impact of seasonal variation on mycorrhizal association in selected industrial wastelands in the Kota district of Rajasthan. In the study mycorrhizal association was quantified in terms of percentage root colonization and spore density in three different seasons. The study was conducted during 2019-2021 and the data was collected for 3 seasons; summer (March-June), Rainy (July–October), and winter (November-February) to study the response to variable climatic factors to the root colonization and spore density of mycorrhiza. To determine the significance of variations in AMF spore density and percentage root colonization during different seasons, one-way ANOVA was performed. Results showed that in all the sites maximum mean spore density was observed in the summer (March-June) season but in the case of percentage root colonization, the value was found maximum in the humid season (July-October) in the control site whereas, in the three experimental sites, the maximum root colonization was observed in summer season (march-June). Hence, it may be concluded that hot climatic condition is favourable for mycorrhizal spore formation and root colonization was also favoured by hot climate.

Identification and Characterization of Arbuscular Mycorrhizal Strains from the Roots and Rhizospheres of Tomato, Brinjal, Chilli and Onion

Rhizosphere soils and roots of two vegetables (tomato and brinjal) and two spices (chilli and onion) crops were collected from each of four Agro-Ecological Zones (AEZs) of Bangladesh viz. AEZ-9 (RARS, Jamalpur), AEZ-11 (RARS, Jashore), AEZ-25 (ARS, Bogura) and AEZ-28 (BARI, Joydebpur) in 2014-2015. Characterization and identification of arbuscular mycorrhizal strains were studied in the microbiology laboratory of the Bangladesh Agricultural Research Institute (BARI). Different crops showed positive responses in percent root colonization such as 74.11-83.78%, 22.11-24.33%, 7.33-8.89%, and 6.67-9.33% in onion, tomato, chilli, and brinjal, respectively. Rhizosphere soil of individual crops had also variations in the number of spore populations such as 120.11-200.33, 33.44-50.78, 36.11-39.22, and 28.56-41.89 per 100g soil in onion, tomato, chilli, and brinjal, respectively. Eleven AM strains were identified in tomatoes: Glomus geosporum, G. mosseae, G. fasciculatum, G. spp., Acaulospora dilatata, A. bireticulata, A. mellea, A. morrowiae, Entrophospora infrequens, Sclerocystis coremioides and Gigaspora margarita. Nine each were identified from other three crops. G. spp. and Acaulospora bireticulata were absent in brinjal and chilli. Acaulospora dilatata and A. mellea were absent in onion. The formation of AM structures was found inconsistent and fluctuating from site to site in the present study. Both oval and spherical-shaped vesicles were found among the AM structures.

The effectiveness of Arbuscula Mycorrhyza Fungi stater with different fortification in increasing the productivity of Clitoria ternatea on saline soil

Saline soil has a high salt content and low productivity, so it is rarely used as agricultural land or forage land for animal feed. Arbuscular Mycorrhizal Fungi (AMF) is a soil fungus that can help plants absorb water and nutrients so that it can help increase plant growth and productivity. This study aimed to evaluate the effectiveness of AMF in increasing the productivity of Clitoria ternatea on saline soil. The research used a completely randomized design (CRD) with a factorial pattern of 5 x 3 with 8 replications. The results showed that the interaction effect of AMF treatment and saline soil was significant (P<0.05) for all variables. This study concluded that saline soil increased the proline content of Clitoria ternatea leaves, and reduced the amount of leaf chlorophyll. AMF could help Clitoria ternatea to overcome saline stress and reduce the use of fertilizer doses by 50%. The addition of AMF increased the total vertical length gain, canopy dry weight, percentage of root colonization, and root dry weight. The type of AMF product IPB 2 gave the best results.

The effect of humic acid on biological properties of soil and upland rice plants in entisol Coastal Bengkulu City

Entisol is a type of soil on coastal land that has low soil fertility, low soil aggregation, low organic matter content, low soil microorganism activity and high salt content that can affect growth and development of crop yields. Application of humic acid is expected to increase the fertility of the entisol soil. This study aims to measure the effect of humic acid application on soil biological properties and yields of upland rice in Entisol Pesisir, Bengkulu city. The research was carried out in July-November 2020 in the Beringin Raya Village, Muara Bangkahulu District, Bengkulu City. The research design used a two-factor Completely Randomized Block Design with four replications, arranged in a factorial manner in experimental units. The first factor is humic acid which consists of not given humic acid, and given humic acid. The second factor is upland rice varieties consisting of Inpago 10, Merah rice, and Putih rice. The results showed that the application of humic acid was able to increase the biological activity of the soil including the total microbial population of 68.73% and the percentage of root colonization reaching 23.65% and increasing the pH, and rice yields per plot reached 14.2%. Inpago variety has better adaptability than local varieties (Merah and Putih) which is indicated by soil biological activity such as total microbial population reaching 570.16 x 106 CFU g-1 with root colonization percentage reaching 88.75%, pH, and upland rice yield per plot was 2033.68 g/plot. So based on the results of the study, it is recommended to cultivate Inpago 10 varieties compamerah to local varieties.

Identification and Characterization of Arbuscular Mycorrhizal Strains from the Roots and Rhizospheres of Tomato, Brinjal, Chilli and Onion

Rhizosphere soils and roots of two vegetables (tomato and brinjal) and two spices (chilli and onion) crops were collected from each of four Agro-Ecological Zones (AEZs) of Bangladesh viz. AEZ-9 (RARS, Jamalpur), AEZ-11 (RARS, Jashore), AEZ-25 (ARS, Bogura) and AEZ-28 (BARI, Joydebpur) in 2014-2015. Characterization and identification of arbuscular mycorrhizal strains were studied in the microbiology laboratory of the Bangladesh Agricultural Research Institute (BARI). Different crops showed positive responses in percent root colonization such as 74.11-83.78%, 22.11-24.33%, 7.33-8.89%, and 6.67-9.33% in onion, tomato, chilli, and brinjal, respectively. Rhizosphere soil of individual crops had also variations in the number of spore populations such as 120.11-200.33, 33.44-50.78, 36.11-39.22, and 28.56-41.89 per 100g soil in onion, tomato, chilli, and brinjal, respectively. Eleven AM strains were identified in tomatoes: Glomus geosporum, G. mosseae, G. fasciculatum, G. spp., Acaulospora dilatata, A. bireticulata, A. mellea, A. morrowiae, Entrophospora infrequens, Sclerocystis coremioides and Gigaspora margarita. Nine each were identified from other three crops. G. spp. and Acaulospora bireticulata were absent in brinjal and chilli. Acaulospora dilatata and A. mellea were absent in onion. The formation of AM structures was found inconsistent and fluctuating from site to site in the present study. Both oval and spherical-shaped vesicles were found among the AM structures.

Mycorrhizal Colonization Modulates the Essential Oil Profile and Enzymatic and Non-Enzymatic Antioxidants to Mitigate the Adverse Effects of Water Deficit in Salvia subg. Perovskia.

Among traditional Iranian herbs, Perovskia species (a subgenus of Salvia), while being valued ornamentals, are also studied for numerous potential pharmacological and therapeutic aspects. The current study was conducted to assess the effectiveness of two species of arbuscular mycorrhizal fungi (AMF), Funneliformis mosseae and Rhizophagus intraradices, separately and in combination, in terms of the essential oil content and compositions along with the enzymatic and non-enzymatic antioxidants in Salvia abrotanoides and S. yangii in response to three levels of irrigation, including 100% FC as well-watered, 75% FC (moderate irrigation deficit), and 50% FC (severe irrigation deficit). In both species, essential oil content, enzyme antioxidant activities, total phenolics, and flavonoids were increased significantly with the severity of stress; this increase was more pronounced in mycorrhizal inoculated herbs. Furthermore, leaf phosphorus concentration, relative water content, chlorophylls a and b, and total carotenoids decreased in parallel with reducing soil moisture; albeit, AMF inoculation improved the stress symptoms under increasing severity of water restriction compared with their control conditions. In addition, the percentage of root colonization was positively correlated with the relative water content (RWC) and leaf phosphorus concentration. Taking into account the essential oil groups, AMF colonization elevated some essential oil components, such as oxygenated monoterpenes, 1,8-cineol, camphor, and borneol, whereas the main sesquiterpenes, including E-β-caryophyllene and α-humulene, remarkably decreased. Taken together, these findings highlighted the role of symbiosis with AMFs in increasing the tolerance of water deficit stress in S. abrotanoides and S. yangii and improving their essential oil composition.

Role of auxin in the symbiotic relationship between Piriformospora indica and rice plants

Piriformospora indica (P. indica) is a beneficial endophytic fungus colonized with roots of a wide range of host plant species; however, the mechanisms of P. indica symbiosis with different plants could vary and need to be further addressed. Our study showed that root architecture and growth behaviors were changed in P. indica-colonized rice plants. The P. indica-induced primary root shorting and coiling phenomena were consistent with the auxin-responsive phenotype, suggesting that the auxin levels of P. indica-colonized roots were modulated. To investigate the changes in auxin levels, auxin-responsive gene expressions and promoter activities were used as indicators to monitor auxin levels in root tissues. The results showed that the auxin levels of primary roots were increased in P. indica-inoculated seedlings. Furthermore, an auxin inhibitor (p-chlorophenoxyisobutyric acid, PCIB) was applied to block auxin action to confirm whether auxin is a critical factor in regulating P. indica-induced root growth. The P. indica-induced root architecture modification was significantly repressed by PCIB which was added to the rice culture solutions at the initiation of P. indica inoculation. A proposed hypothesis was that the PCIB treatment might result in lower colonization and further reduce the influence of P. indica colonization on root architecture. The effect of PCIB on colonization was observed by counting the percent root colonization. The data showed that the colonization levels of P. indica in PCIB-treated seedlings were significantly decreased. Taken together, our data indicated that auxin levels would be increased in P. indica-colonized rice roots. Moreover, it was demonstrated that auxin has dual roles in the symbiotic relationship between rice and P. indica, which is a signal that triggers P. indica-induced root growth and a positive factor involved in the colonization mechanism.