Plant Microbe Interaction

Medicinal plants are considered to have high biological effectiveness and a rich source of active substances, including the rosemary plant, which is found in both its wild and cultivated forms over a wide geographical range in Libya. The rosemary plant (Rosmarinus Officinalis L), which belongs to the Lamiaceae family, is considered one of the high-end plants used in folk medicine. The study included different environmental locations of the rosemary plant in western Libya, to determine the effect of water leave extract at different concentrations (20, 40, 60, 80) %, and some if antibiotics against growth of Staphylococcus aureus bacteria by used the diffusion method. By well etching on MHA medium against three isolates of methicillin-resistant bacteria (MRSA) and one vancomycin-resistant isolate (VRSA), where the results showed an inhibitory activity of the plant extracts against Staphylococcus aureus bacteria, which differed according to the environment in which the plant grew, and the best concentrations were as for inhibition, the concentration is 80% with an inhibition diameter of (17) mm and (16) mm for Tarhuna and Misrata extracts, respectively. Also, all MRSA isolates showed sensitivity to antibiotics except for the antibiotics Augmentin and Cefoxitin, in addition to the VRSA isolate, which was resistant. For vancomycin. Through the study, it was found that a concentration of 80% has an inhibitory effect on the bacteria used. Therefore, this study recommends using the aqueous extract of the rosemary plant and knowing the extent of its effect on several types of bacteria, and studying the plant from an environmental perspective by tracking its content of active substances and studying its activity with the changing environment.

Rice genotypes were evaluated for resistance to the Brown Plant Hopper (BPH), Nilaparvata lugens Stal in SVPUA & T Meerut, were evaluated for resistance in greenhouse screening tests. Over a period of two years (2017 and 2018), 17 rice cultivars were screened using the plant standard seed box screening technique. The results showed 6 rice varieties viz. REMRE-1, RPMRE-2, RPMRE-3, RPMRE-5, RIL501 and PTB-33 were possessing high level of resistance to the BPH. 3 rice varieties viz., Vallabh Basmati-24, Pusa Sugandha-5, Taraori Basmati and Pusa Basmati-1 were moderately resistant. 4 rice varieties viz., Kasturi, Vallabh Basmati-23, Vallabh Basmati-22, Improved Pusa Basmati-1460 were moderately susceptible and 3 rice varieties viz., Pusa Basmati-6, Pusa Basmati-1121 and Pusa Basmati1509 were susceptible, according to standard evaluation system (IRRI, 1992) Standard Seed Box Screening technique (SSST).

The aim of this study was to optimize the cultural conditions for optimal fungal growth and metabolic bioactivity of Rhizoctonia solani isolated from potato tubers in Basra, Iraq. Different culture media, temperatures, pH and carbon and nitrogen sources were used to elucidate their effects on the fungal growth response and bioactivity of the fungal metabolite against two bacteria strains E. coli and S. aureus. R. solani grew better on Trypto Soyo broth medium at pH 6 and temperature 30 C. Starch (C- source) and NaNOR3R (N-source) were most suitable for the fungus growth. Highest dry weight of fungal crude extract was obtained by using TS broth medium at pH 6 and incubation temperature 30 C. A disc diffusion technique was applied to examine the bioactivity of fungal crude extract against two strains of bacteria E. coli and S. aureus. The fungus exhibited higher antibacterial metabolic bioactivity (30 mm and 34 mm inhibition zones diam) against E. coli and S. aureus, respectively, by using TS broth medium amended with starch and (NHR4R)R2RSOR3R at pH 6 and 25 C temperature.

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Infestasi ulat kantong (Metisa plana) merupakan salah satu masalah utama yang dapat menyebabkan kerusakan serius pada tanaman kelapa sawit, mengakibatkan penurunan produksi. Penelitian ini bertujuan untuk mengidentifikasi kerusakan akibat infestasi ulat kantong pada tanaman kelapa sawit menggunakan analisis multi-indeks vegetasi dan algoritma K-Nearest Neighbors (KNN). Data citra multispektral yang diambil menggunakan drone UAV DJI Phantom 4 Multispektral dianalisis untuk mendapatkan nilai dari sepuluh indeks vegetasi, yaitu NDVI, NDRE, GNDVI, ARVI, PRI, MSAVI, SAVI, VARI, EVI, dan OSAVI. Data ini kemudian diolah menggunakan metode Synthetic Minority Over-sampling Technique (SMOTE) untuk mengatasi ketidakseimbangan kelas pada data. Analisis statistik non-parametrik, seperti uji Kruskal-Wallis dan uji Dunn's, digunakan untuk menentukan signifikansi perbedaan antar kelompok infestasi ulat kantong. Hasil uji menunjukkan bahwa semua indeks vegetasi yang diuji memiliki perbedaan signifikan antar kelompok. Model KNN kemudian diterapkan untuk mengklasifikasikan tingkat kerusakan berdasarkan indeks vegetasi yang paling signifikan. Model terbaik dipilih berdasarkan evaluasi akurasi dari beberapa rasio pembagian data (80:20, 70:30, 75:25). Model yang terpilih digunakan untuk pembuatan peta prediksi kerusakan akibat infestasi ulat kantong pada tanaman kelapa sawit. Penelitian ini menunjukkan bahwa kombinasi analisis multi-indeks vegetasi dan KNN dapat memberikan hasil yang akurat dalam mendeteksi dan memetakan tingkat kerusakan akibat infestasi ulat kantong, yang diharapkan dapat menjadi alat yang efektif untuk pemantauan dan pengendalian hama secara dini.

This study was conducted to determine the effects of crude extracts of betelnut, derris root, or wild heliotrope on the feeding response of two slug species, Filicaulis bleekeri and Parmarion pupillaris. Feeding test was performed in Petri dishes lined with wet white muslin by exposing 3 cm diameter leaf discs of treated -1 chinese cabbage with each extract (concentration of 50 g 100 ml water) to each slug species for 6 days. Control leaf discs were treated with water. Feeding response was measured by weighting leaf disc before and after 24 h feeding totaled into 6 days feeding period. Betel nut extract was further tested outdoor at the -1 concentration of 0 (control), 12.5, 25, and 50 g 100 ml . Filicaulis bleekeri (three slugs for each extract concentration) were released into each bucket and allowed to feed for 6 days. Percentages of leaf damage (consumed) by the slugs were measured at day 2, 4, and 6 after exposure. The results showed that crude extract of betelnut and derris ro...

Rice false smut (RFS) instigated by the fungus Ustilaginoidea virens, has emerged as one of the most devastating grain diseases in the mainstream of rice-planting regions worldwide. A total of fty six distinct isolates of Ustilaginoidea virens collected from different states of India were characterized morphologically and also at molecular level. Isolates showed variation in the size of the spore, color of mycelium and shape of the hyphae. The spores were globose, irregularly round to elliptical and warty on the surface with diameters ranging from 4.12 to 6.34 µm. The maximum colony diameter was found in Telangana isolate Uv305 (66.00 mm) and minimum was in Uttar Pradesh isolate Uv214 (17.50 mm). Genetic Diversity was analyzed by using 12 SSR primers out of which 7 were found to be polymorphic The number of alleles per locus vary from 5 to10. The maximum number of polymorphism was shown by UvSSR97 followed by UVSSR79, UvSSR226 and Uv SSR276 while least polymorphism was observed in UvSSR107, and Uv163 primer. The Dendrogram generated based on polymorphic data revealed a considerable amount of diversity by grouping the isolates in ve clusters. The PIC ranged from 0.079 to 0.900. The value of Shannon information index ranged from 2.99 to 4.52. The pairwise population xation index (F ST ) value also indicated signi cant genetic variation among all compared geographical populations. All the isolates could be grouped into three groups according to their genetic structure con rmed through model based cluster algorithm using STRUCTURE v2.3.4. This in-depth understanding of U. virens population structure and diversity holds valuable implications for effectively managing rice false smut disease on a comprehensive scale. This study offers comprehensive insights into the morphology, genetic diversity, and population structure of U. virens strains sourced from various agro-climatic regions in India. A total of 56 U. virens isolates, originating from 8 geographical populations, were categorized into three distinct genetic subgroups, revealing genetic variations both within and among geographical populations.

Stem bleeding disease caused by Thielaviopsis paradoxa is also one of the important diseases in coconut in Andhra Pradesh. Bio efficacy of native fungal and bacterial bioagents on stem bleeding pathogen Thielaviopsis paradoxa under in vitro conditions revealed that Trichoderma asperellum [Ambajipeta] was significantly superior with
79.17% growth inhibition followed by T. reesei [Ambajipeta] with 78.33%. Field evaluation of bio-control agents against Stem bleeding disease in coconut indicated that the cake application of T. harzianum and T. reesei formulation completely brought down the disease index by 100 per cent within 50 days of cake application. Paste application of bioagents viz., T. harzianum, T. reesei, and chemical fungicide copper oxychloride application also substantially reduced the disease.

Keywords: Stem bleeding disease, coconut, Thielaviopsis paradoxa, Trichoderma coir pith cake, biocontrol.

Tembilahan merupakan salah satu sentra produksi manggis (Garcinia mangostana) di Provinsi Riau. Ciri khas manggis Tembilahan adalah mampu beradaptasi pada zona pasang surut air laut dan waktu berbunga pertama yang cepat. Tujuan dari penelitian ini untuk mengidentifikasi keanekaragaman manggis Tembilahan dan hubungan kekerabatannya berdasarkan karakter morfologi dan agronomi. Penelitian dilakukan pada Juni 2015 sampai Januari 2016 dengan metode eksplorasi. Karakter morfologi dari 50 individu diamati, dideskripsikan dan diskoring. Skoring dianalisis menggunakan software NTSYSpc2,02. Berdasarkan pengamatan dari 51 karakter morfologi manggis diperoleh dua kultivar manggis yaitu kultivar lokal dan kultivar hutan. Koefisien kemiripan yang diperoleh berkisar 0,16 dan 0,82. Dendrogram dengan nilai koefisien kemiripan 0,41 sampai 0,82 terbentuk dua kelompok utama yaitu kelompok pertama terdiri dari 30 individu kultivar lokal dan kelompok dua terdiri dari 20 individu kultivar hutan.

Indonesia is home to a diversity of herbal plants, particularly in Aceh. Moringa oleifera is traditional medicinal plant utilized by locals in the geothermal area Aceh Besar, recognized for its anti-inflammatory properties. However, the bioactive compounds in M. oleifera leaves sourced from Ie Seum have not been documented, making it challenging to explain the roles of the compounds scientifically to anti-inflammatory factors. This research aimed to identify the phytochemical compounds in the ethanol extract of M. oleifera leaves (referred to as EDM) and analyze the physicochemical characteristics of the soil in the geothermal area. This study used a qualitative design to identify EDM compounds with GC-MS and soil physicochemistry. The identification of EDM compounds is conducted through gas chromatography with mass spectrometry (GC-MS). The physicochemical properties of the soil are assessed by examining its texture, pH, organic carbon content, total nitrogen, exchangeable cations, and phosphorus. Sample collection on topsoil (0-20 cm) with an area of 100cmx100cm on one land where M. oleifera plants grow in Ie Seum area in September 2024. A soil sample of 500g was using several methods, namely the hydrometermethod, pH meter, Walkey and Black, ammonium acetate 1M pH 7, Kjeldahl, KCl 1N, Bray 1, HCl 25%, and DTPA extraction. The soil test result showed classified as silty clay. The results GC-MS indicated the presence 11 metabolites, including linolenic acid, phytol, 9,12,15-octadecatrienoic acid ethyl ester, hexadecanoic acid, neophytadiene, gamma-tocopherol, vitamin E, squalene, icosane, and beta-pinene. EDM from the Ie Seum contains compounds that are beneficial in anti-inflammatory.

Fil: Sadanoski, Marcela Alejandra. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Quimicas y Naturales. Departamento de Bioquimica Clinica. Laboratorio de Biotecnologia Molecular; Argentina

Abiotic stress is a critical limiting factor for crop output, food quality, and global food security. Plant physiological, biochemical, and molecular characteristics are all impacted when they are stressed. The loss of soil microbial diversity, soil fertility, and competition for nutrient resources are the main effects of these pressures. Because the use of inorganic fertilizers and pesticides in agriculture techniques depletes soil fertility and pollutes the ecosystem. As a result, it is vital to develop more secure and long-term agricultural production methods. Plant growth promoting microorganisms (PGPM) and mycorrhizal fungi are used to improve plant development. It provides a cost-effective and environmentally friendly means of shielding plants from stress. Plant growth may be aided by PGPM, which regulates plant hormones, improves nutrient acquisition, produces siderophores, and boosts the antioxidant system. Arbuscular mycorrhizae (AM) boost stress tolerance by increasing the delivery of nutrients and water during stressful situations. Because it relies on biological processes and replaces conventional agriculture procedures, this plant-microbe interaction is critical for sustainable agriculture and industrial purposes. As a result, bacteria may play an important role as an ecological engineer in resolving environmental issues.

Entomopathogenic fungi (EPF) Metarhizium anisopliae are fungal species that is the frequently occurring and destructive pest management to the pathogenic soil and insects. The effect of different substrates for the mass production of Metarhizium anisopliae spore/ml was significantly higher recorded The results revealed that all the treatments were significantly producing spore per ml and thus increasing the yield significantly as compared to other substrates. The results revealed that all the treatments were significantly higher effective in producing spore/ml as compared to other substrates overall finding showed that substrate tested, for Metarhizium anisopliae spore/ml production was significantly higher recorded 240.53 and 195.26 spore/ml were recorded on substrate irrespective of the temperature.

Experiment was conducted in laboratory and field to find out the comparative performance of few biocontrol agents and fungicides and their integration for management of web blight (Rhizoctonia solani Kühn) in French bean. Efficacy of four bioagents, Trichoderma viride, Trichoderma harzianum, Trichoderma virens and Aspergillus niger was tested in vitro. All the bioagents significantly inhibited the mycelial growth as well as number of sclerotia of R. solani. The maximum mycelial growth inhibition (62.12 %) was observed by T. harzianum followed by T. viride (57.28 %), T. virens (51.38 %) and A. niger (46.72 %), respectively. The per cent reduction in the number of sclerotia was also maximum by T. harzianum

The extensive use of synthetic pesticides has a harmful impact on the environment, plants and animal health. It is a big challenge for all farming systems to develop novel approaches, which are eco-friendly and improve food quality. As compared to synthetic pesticides, the use of beneficial microbes is the best option to maintain the environmental condition because they are cost-effective and ecofriendly. In the recent era, biological antagonistic microorganisms (Trichoderma spp.) are the best approach to control the soil-borne fungal pathogens associated with plant roots of agriculturally important crops. Due to fast growth and rhizospheric colonization ability, this fungus competes with other pathogenic soil-borne fungi by producing different metabolites (volatile and non-volatile). Trichoderma protected the plants from pathogenic fungi through mycoparasitic and antibiosis capability. Furthermore, it has the ability to improve plant health by inducing SAR (Systemic acquired resist...

It has long been believed that maintenance of low Na +: K + ratios in the cytosol of plant cells is critical to the plant’s ability to tolerate salinity stress. Direct measurements of such ratios, however, have been few. Here we apply the non-invasive technique of compartmental analysis, using the short-lived radiotracers 42 K + and 22 Na +, in intact seedlings of barley (Hordeum vulgare L.), to evaluate unidirectional plasma membrane fluxes and cytosolic concentrations of K + and Na + in root tissues, under eight nutritional conditions varying in levels of salinity and K + supply. We show that Na +: K + ratios in the cytosol of root cells adjust significantly across the conditions tested, and that these ratios are poor predictors of the plant’s growth response to salinity. Our study further demonstrates that Na + is subject to rapid and futile cycling at the plasma membrane at all levels of Na + supply, independently of external K +, while K + influx is reduced by Na +, from a simi...

ABSTRACTIt has long been believed that maintenance of low Na+ : K+ ratios in the cytosol of plant cells is critical to the plant’s ability to tolerate salinity stress. Direct measurements of such ratios, however, have been few. Here we apply the non‐invasive technique of compartmental analysis, using the short‐lived radiotracers 42K+ and 22Na+, in intact seedlings of barley (Hordeum vulgare L.), to evaluate unidirectional plasma membrane fluxes and cytosolic concentrations of K+ and Na+ in root tissues, under eight nutritional conditions varying in levels of salinity and K+ supply. We show that Na+ : K+ ratios in the cytosol of root cells adjust significantly across the conditions tested, and that these ratios are poor predictors of the plant’s growth response to salinity. Our study further demonstrates that Na+ is subject to rapid and futile cycling at the plasma membrane at all levels of Na+ supply, independently of external K+, while K+ influx is reduced by Na+, from a similar ba...

Potassium (K +) is an essential nutrient and the most abundant cation in plant cells. Plants possess two transport systems for K + acquisition: a high-affinity system (HATS), operating at external K + concentrations ([K + ] ext) below 1 mM, and showing reduced transport activity in the presence of ammonium (NH 4 +); and, a low-affinity system (LATS), operating at [K + ] ext above 1 mM, that is not affected by NH 4 +. K + transport and compartmentation were investigated in barley (Hordeum vulgare L.) and rice (Oryza sativa L.) using the non-invasive technique of compartmental analysis by tracer efflux (CATE), to simultaneously determine unidirectional membrane fluxes, ion concentrations, and exchange characteristics in subcellular compartments. These studies revealed striking differences in unidirectional K + fluxes between HATS and LATS. It was found that flux measurements, using traditional direct influx (DI) protocols, accurately represented HATS influx, but underestimated LATS influx by as much as seven-fold. In both barley and rice, LATS K + fluxes were found to undergo rapid, futile cycling, with the ratio of efflux:influx 3 to 5 times greater, and the cytosolic exchange rate 2 to 3 times faster than under HATS. Based upon plasma-membrane electrical potential measurements, efflux was found First and foremost, I would like to express my thanks and gratitude to my thesis supervisor Dr. Herbert J. Kronzucker. I consider myself fortunate to have had the opportunity to work with Dr. Kronzucker, as he has been more than simply an instructor, he has been a mentor, whom I admire and respect immensely. He has taught me that while conducting experiments in a regimented, meticulous manner is necessary for scientific discovery, the foremost ability of a researcher is their capacity to discuss interesting questions, propose novel ideas, and question what is considered the truth, using logic and evidence. I am grateful for his guidance, his persistence, his impatience, and for all the time he has spent helping me. In addition to my supervisor, there are many individuals that have supported me during my graduate experience. Firstly, Dr. Dev Britto, who has been a wonderful influence throughout my graduate studies. I am most appreciative of his efforts to ensure that I would find the "Ph". I can only hope to aspire to reach the level of brilliance that he possesses. I would like to thank the members of my PhD supervisory committee, Drs. George Espie, Robert Jefferies, and Rowan Sage, for their guidance and support, particularly while sitting through one of my riveting committee meeting presentations, I am sure we will all miss those events. Drs. Andrew Mason and Roger Lew, thank you for your invaluable advice and guidance in unlocking the mysteries of electrophysiology. Mike Butler and coworkers at McMaster University, thank you for never failing to satisfy my thirst for 42 K + or 24 Na + , and Dr. Alan Wilson and coworkers at the Centre for Mental Health and Addiction (CAMH) for providing me, relatively regularly, with 13 N. Dr.

The study was made to detect and identify antagonistic bacteria to control Rhizoctonia solani, a causal organism of sheath blight (ShB) disease of rice. Isolation of antagonistic bacteria was done from ShB infected rice leaf collected from the districts of Gazipur, Rajshahi, Bogra and Comilla. Fifty isolates of bacteria were isolated. These isolates were tested for antagonism against ShB pathogen of in PDA medium. Among the isolates of antagonistic bacteria (both fluorescent and non fluorescent), eleven produced more than 15 mm inhibition zone, were selected for this study. Remarkable inhibition zone producing ten isolates were selected to observe their antagonistic behaviour by soaking the sclerotia of Rhizoctonia solani and rice seedlings in different hours into bacterial suspension of 3.84 x 10 7 CFU/ml. Both the in vitro and in vivo rom showed that the sclerotial germination and sheath blight symptom expression were delayed 6-9 days. Soaking of both seedlings and sclerotia with the test bacteria was found most effective to control ShB (38%-100%) than soaking of seedlings alone with bacterial suspension at different hours. However, BanShbFPS5 (2)B, BanShb738(3), BanShb738(2) and BanShb581(1), the four antagonistic bacterial isolates could be applied as biological agent to control sheath blight disease of rice and they could control sheath blight disease development and could delay the epidemics of the disease.

Plant beneficial rhizobacteria (PBR) is a group of naturally occurring rhizospheric microbes that enhance nutrient availability and induce biotic and abiotic stress tolerance through a wide array of mechanisms to enhance agricultural sustainability. Application of PBR has the potential to reduce worldwide requirement of agricultural chemicals and improve agro-ecological sustainability. The PBR exert their beneficial effects in three major ways; (1) fix atmospheric nitrogen and synthesize specific compounds to promote plant growth, (2) solubilize essential mineral nutrients in soils for plant uptake, and (3) produce antimicrobial substances and induce systemic resistance in host plants to protect them from biotic and abiotic stresses. Application of PBR as suitable inoculants appears to be a viable alternative technology to synthetic fertilizers and pesticides. Furthermore, PBR enhance nutrient and water use efficiency, influence dynamics of mineral recycling, and tolerance of plants to other environmental stresses by improving health of soils. This report provides comprehensive reviews and discusses beneficial effects of PBR on plant and soil health. Considering their multitude of functions to improve plant and soil health, we propose to call the plant growth-promoting bacteria (PGPR) as PBR.

Six rice cultivars were shown to have measurable levels of rate-limiting resistance (RLR) to blast disease in the seedling stage in the greenhouse, as compared to a susceptible cultivar. The criteria for RLR were: a consistent ability to reduce receptivity, sporulation capacity and an extension of the latent period. Another method for a quantitative evaluation of the RLR to blast disease was developed. This procedure used sub-lethal concentrations of the systemic fungicide Tricyclazole. It was found that a certain threshhold (225-525 fig a.i./ml) of fungicide concentration could be used to determine different levels of RLR and that the minimum concentration of the fungicide needed for complete inhibition of the disease in a given cultivar is related to the level of its RLR. Zusammenfassung Eine Bewertung der Rate-Limiting-Resistenz gegen die Blastkrankheit in Reissorten durch nichttoxische Konzentrationen eines systemischen Fungizids In Gewachshausuntersuchungen konnte gezeigt werden, dafi sechs Reissorten mefibare Rate-Limiting-Resistenz (RLR)-Grade im Keimlingsstadium, verglichen mit einer anfalligen Sorte, besitzen. Die Merkmaie fiir RLR waren: eine anhaltende Fahigkeit, die Empfanglichkeit und Sporulationsleistung zu reduzieren und die latente Periode zu verlangern. Eine weitere Methode, um RLR gegen die Blastkrankheit quantitativ bemessen zu konnen, wurde entwickelt. Diese Methode verwendete nichttoxische Konzentrationen des systemischen Fungizids Tricyclazol. Festgestellt wurde, dafi bei der Anwendung von bestimmten Fungizidkonzentrationen (225-525 fig a.i./ml) verschiedene RLR-Grade unterschieden werden konnten und dafi die Fungizidkonzentration, die das Minimum, um die Krankheit bei einer Sorte ganzUch aufzuhalten, darstellte, mit dem Grad dessen RLR verbunden war.

Viable population of five isolates of Trichoderma harzianum were processedl formulated as prills using CaCl 2 and Ca-gluconate (Ca-G) as gellant for increasing shelf life of a biocontrol agent. The results showed that survivability of T. harzianum was higher (60-77 days) when Ca-G was used than when CaCl 2 (32-45 days) was used as gellant. Survivability of most isolates was higher when initial population of 10 9 was used than when it was 10 6 /g of prills.

The temporal and spatial progress of sheath blight was assessed on a set of mega rice varieties of South Asia and local varieties of North India in field experiments for two consecutive years. With artificially created disease focus disease severity was recorded on five un-inoculated plants from the focus in four directions after two, four and six weeks of inoculation. The mega varieties differed in their level of susceptibility to sheath blight. The temporal progression of the disease was significantly increased in Swarna and Swarna Sub-1 followed by PR 114 and PR 121 varieties. Area under disease progress curve (AUDPC) ranged 184.92-683.67 in tested varieties. The disease severity decreased as the distance from the disease focus increased in all varieties, the significance of the spatial spread depended on the susceptibility level of the variety. Swarna and Swarna Sub-1 showed higher level of susceptibility. The exponential regression model explained the increased severity with time which get decreased with increase in distance from the disease focus. Relationship of week after inoculation with disease severity indicated that model explained 96.0% variability of the response data in Swarna. The morphological traits like plant height, number of tillers per hill and tiller angle of the varieties had a significant correlation with the disease severity and incidence. In the absence of genetic resistance, this study provides evidence of requirement of a six-week period for differentiating the susceptible or resistant response of rice varieties to sheath blight under field conditions. Plant morphological traits are the key factor which can be consider in disease resistant breeding programme.

In this study a strain of Streptomyces sp. was isolated from soil and identified by 16S rRNA gene sequencing technology. The strain was screened for antibiotics production effective against biocontrol of Rhizoctonia solani AG-3 to cure the target spot disease in tobacco. For enhance production of secondary metabolites, central composite design of response surface methodology (RSM) was applied in submerged fermentation. The maximum metabolite production was using medium volume of 55 mL in 250 mL flask, agitation speed of 165 rpm, incubation temperature 30 C, initial medium pH of 6.8 and inoculum size of 7%. Solvent extraction method was used to extract the secondary metabolites and active compounds were purified by silica gel column chromatography. The purified fractions were further investigated by gas chromatography-mass spectrophotometer (GC-MS). GC-MS analysis showed 48 compounds, among them 12 were active against pathogen. These findings indicated that the strain Streptomyces TA 1123 was a potential antagonist against R. solani AG-3.

Soil, air and water pollution have become a global problem due to unprocessed emission of toxic heavy metals into the environment. The uncontrolled increase in release of hazardous heavy metals such as arsenic into the soil and water is mainly due to the untreated industrial waste. The accumulation of heavy metals causes damage not only to soil and water flora but also have deleterious effects on human health. The conventional methods such as thermal treatment, excavation and land fill, electro-reclamation and acid leaching used for degradation were time and cost consuming with release of toxic products. In nature, there are microorganisms residing in soil, which are capable of degrading toxic metals through phytoremediation. In phytoremediation, rhizobacteria play an important role. Rhizobacteria not only prevent contaminated soil's fertility but also enhance the growth of plants by release of special plant growth hormones. Phytohormones secreted by plant growth-promoting rhizobacteria (PGPR) are major chemicals involved in metal uptake. This in situ and environment friendly method of bioremediation is cost effective and efficient. The advance techniques such as genetic engineering have been introduced to increase the spectrum and degrading capacity of rhizobacteria.

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Climate change, urbanization, and population increase limit food availability. To sustain human existence, there is the need to increase food and agricultural production to mitigate the impact of these factors. Scientists have been working for years on ways to increase food production. From plant breeding techniques to soil science, scientists have made tremendous progress. The rhizobiome has been proven to be important to crop production, and the impact of the rhizobiome on plant health cannot be overemphasized. Being rich in diverse complex microbial interactions, the rhizosphere has become a major force in recent plant growth promotion studies. The upsurge in next-generation sequencing applications with the various "omics" technologies is helping to unearth information relating to rhizosphere impact on plant growth. Explaining the complex interactions between and across microbial species present in the rhizosphere is important to further enhance our understanding of their mechanistic and mutualistic functions. Knowledge from this can be used in rhizosphere biome engineering for improved plant growth and yield in the face of the various biotic and abiotic challenges.

Sheath blight, caused by the pathogen Rhizoctonia solani Kühn, is one of the most serious diseases of rice and leads to severe yield losses worldwide. A recombinant inbred line (RIL) population consisting of 122 lines was constructed from a cross between Danteshwari a high yielding popular rice cultivar but moderately susceptible to water stress, susceptible to sheath blight and Dagad Deshi a tall deep rooted poor yielder and tolerant to water stress and sheath blight. Five traits, namely infected tillers per hill, lesion size (total coalescing lesions) and individual lesion (one spot) and lesion's length and width) were used to evaluate sheath blight resistance. Using the RIL population and 162 molecular markers, 11 quantitative trait loci (QTLs) were identified for the five traits. Identification of map position was accomplished by identifying BAC or PAC clones that simultaneously contained a hit from the microsatellite / HvSSR marker further helped us to generate a high resolution molecular marker map of the identified QTL region. Identified QTLs were located on seven chromosomes. A major QTL for infected tillers per hill on chromosome 1 was identified with phenotypic variance of 18.02%. Six QTL's with positive additive effect and one with negative additive effects was identified indicating alleles at these loci are being contributed by either of the parents respectively.

The increase of human population and associated increasing demand for agricultural products lead to soil over-exploitation. Biofertilizers based on lyophilized plant material containing living plant growth-promoting microorganisms (PGPM) could be an alternative to conventional fertilizers that fits into sustainable agricultural technologies ideas. We aimed to: (1) assess the diversity of endophytic bacteria in sugar and sea beet roots and (2) determine the influence of osmoprotectants (trehalose and ectoine) addition during lyophilization on bacterial density, viability and salt tolerance. Microbiome diversity was assessed based on 16S rRNA amplicons sequencing, bacterial density and salt tolerance was evaluated in cultures, while bacterial viability was calculated by using fluorescence microscopy and flow cytometry. Here we show that plant genotype shapes its endophytic microbiome diversity and determines rhizosphere soil properties. Sea beet endophytic microbiome, consisting of ge...

Investigations were carried out during the months of October to March on various common specimens viz, paddy straw, stubbles, weed straw, soil, rice residue (husk), seeds and undecomposed organic material to ascertain the perpetuation of blast pathogen (M. grisea) under temperate conditions. The results indicate that in all the samples collected, highest frequency (14.15%) of blast pathogen (M. grisea) was recorded in the month of October. However, month of March showed least occurrence (2.50%). Among collected samples, maximum perpetuation of blast pathogen (M. grisea) was exhibited by stubbles (14.35%) followed by paddy straw (12.37%) and the minimum were exhibited in undecomposed material (1.60%), followed by weed straw (3.40%) and soil (5.8%). It was concluded that these studied components are the possible sources of perpetuation for rice blast pathogen.

Rice is globally the most important food crop and there is a dire need to feed the ever-increasing population by improving its productivity. It has been realised that diseases are the major impediment towards enhancing the productivity of this crop. Despite the advent of modern effective disease control measures such as use of chemicals, bioagents and resistant varieties; agronomic practices still play a vital role in disease management in rice. Optimum use of different agro-techniques can be exploited for efficient control of various devastating diseases like rice blast, sheath blight, bakanae and many more by providing a favourable environment to better crop survival. Besides, appropriate selection of a variety, use of quality seed, method of establishment, planting time, nutrient, water and weed management practices can be well exploited to control various diseases. This manuscript entails to review the work pertaining to use of agronomic practices for exploiting the potential of...

Trichoderma is used as a bio-agent and have been reported to be quite effective, inexpensive and eco-friendly. It can be used as seed treatment, applied direct to the soil before planting and added to organic fertilizers. Trichoderma controls the pathogenic organism by competition, mycoparasitism and antagonism. It excretes enzymes like viridin and gleotoxin thereby enhancing the root growth. Hence, it has got significant importance in ecofriendly disease management programs. The first step while studying the bio-control, is the identification of a promising biocontrol agent. Once the bio-control agent is identified and is proven effective against plant pathogens over several reproducible results, the method of mass production, formulation and application should be taken into consideration to stabilize the product during storage and to facilitate its delivery to the plant. The major hurdle in the use of bio-pesticides is their shelf life and inconsistent performance. Therefore, the present study "Shelf life studies of different formulations of Trichoderma harzianum" was undertaken at biological control lab, NIPHM Hyderabad with the objectives: Evaluation of solid and liquid substrates for mass production of T. harzianum and Shelf life studies of different formulations of T. harzianum. From the study it was found that all the prepared formulations retained optimum viability. Capsule and sachet based formulations gave higher shelf life of Trichoderma as compared to wettable formulations. Application of Capsule and sachet based formulations would be more convenient for application, storage and handling to control diseases in field and orchards which in turn would help the farmers to achieve a better crop yield.

In soils multi-contaminated with heavy metal and metalloids, the establishment of plant species is often hampered due to toxicity. This may be overcome through the inoculation of beneficial soil microorganisms. In this study, two arsenic-resistant bacterial isolates, classified as Pseudomonas gessardii and Brevundimonas intermedia, and two arsenic-resistant fungi, classified as Fimetariella rabenhortii and Hormonema viticola, were isolated from contaminated soil from the Puchuncaví valley (Chile). Their ability to produce indoleacetic acid and siderophores and mediate phosphate solubilization as plant growth-promoting properties were evaluated, as well as levels of arsenic resistance. A real time PCR applied to Triticum aestivum that grew in soil inoculated with the bacterial and fungal isolates was performed to observe differences in the relative expression of heavy metal stress defense genes. The minimum inhibitory concentration of the bacterial strains to arsenate was up to 7000 ...

In vitro experiment was carried out to see the effect of saw dusts of Pinus kesiya, Shorea robusta, and Callicarpa arborea on Trichoderma harzianum, isolate TH-13 mass production, along with its biotization effect on Capsicum chinensis Jacq. “Bhut Jolokia.” Early mycelium initiation (2 days) occurred in S. robusta followed by P. kesiya and C. arborea (3.5 days). The sporulation was observed earlier in S. robusta (100% after 6 days) than P. kesiya (33.4% after 8 days) and C. arborea (16.7% after 9 days) but no sporulation was observed in control. The complete sporulation was also earlier in S. robusta (100% after 10 days) than P. kesiya (33.4% after 15 days) and C. arborea (16.4% after 18 days). Higher conidial yield 86×106 was also in S. robusta than P. kesiya 70×106 and C. arborea 45×106, respectively. The increase in height (60–70 cm), number of leaves (600–650), and yield of chili (120–150 fruits) were also more in inoculated C. chinensis seedlings than control. It is concluded t...

Plants develop responses to abiotic stresses, like Fe deficiency. Similarly, plants also develop responses to cope with biotic stresses provoked by biological agents, like pathogens and insects. Some of these responses are limited to the infested damaged organ, but other responses systemically spread far from the infested organ and affect the whole plant. These latter responses include the Systemic Acquired Resistance (SAR) and the Induced Systemic Resistance (ISR). SAR is induced by pathogens and insects while ISR is mediated by beneficial microbes living in the rhizosphere, like bacteria and fungi. These root-associated mutualistic microbes, besides impacting on plant nutrition and growth, can further boost plant defenses, rendering the entire plant more resistant to pathogens and pests. In the last years, it has been found that ISReliciting microbes can induce both physiological and morphological responses to Fe deficiency in dicot plants. These results suggest that the regulation of both ISR and Fe deficiency responses overlap, at least partially. Indeed, several hormones and signaling molecules, like ethylene (ET), auxin, and nitric oxide (NO), and the transcription factor MYB72, emerged as key regulators of both processes. This convergence between ISR and Fe deficiency responses opens the way to the use of ISR-eliciting microbes as Fe biofertilizers as well as biopesticides. This review summarizes the progress in the understanding of the molecular overlap in the regulation of ISR and Fe deficiency responses in dicot plants. Root-associated mutualistic microbes, rhizobacteria and rhizofungi species, known for their ability to induce morphological and/or physiological responses to Fe deficiency in dicot plant species are also reviewed herein.

Significance Although plant growth–promoting bacteria (PGPB) enhance the performance of plants, only a few mechanisms have been identified so far. We show that the sulfur metabolisms in both PGPB Enterobacter sp. SA187 and Arabidopsis plants play a key role in plant salt stress tolerance. Salt stress induces a sulfur starvation response in plants that is attenuated by SA187. Arabidopsis sulfur metabolic mutants are hypersensitive to salt stress but can be rescued by SA187. Most plant sulfur metabolism occurs in chloroplasts and is linked to stress-induced accumulation of reactive oxygen species that is suppressed by SA187. This work reveals that plant salt stress tolerance requires the coordinated regulation of the sulfur metabolic pathways in both beneficial microbe and host plant.

Soil, air and water pollution have become a global problem due to unprocessed emission of toxic heavy metals into the environment. The uncontrolled increase in release of hazardous heavy metals such as arsenic into the soil and water is mainly due to the untreated industrial waste. The accumulation of heavy metals causes damage not only to soil and water flora but also have deleterious effects on human health. The conventional methods such as thermal treatment, excavation and land fill, electro-reclamation and acid leaching used for degradation were time and cost consuming with release of toxic products. In nature, there are microorganisms residing in soil, which are capable of degrading toxic metals through phytoremediation. In phytoremediation, rhizobacteria play an important role. Rhizobacteria not only prevent contaminated soil's fertility but also enhance the growth of plants by release of special plant growth hormones. Phytohormones secreted by plant growth-promoting rhizobacteria (PGPR) are major chemicals involved in metal uptake. This in situ and environment friendly method of bioremediation is cost effective and efficient. The advance techniques such as genetic engineering have been introduced to increase the spectrum and degrading capacity of rhizobacteria.

Sheath blight (SB) disease, caused by Rhizoctonia solani Kühn, is one of the most serious diseases causing rice (Oryza sativa L.) yield loss worldwide. A doubled haploid (DH) population was constructed from a cross between a japonica variety CJ06 and an indica variety TN1, and to analyze the quantitative trait loci (QTLs) for SB resistance under three different environments (environments 1-3). Two traits were recorded to evaluate the SB resistance, namely lesion height (LH) and disease rating (DR). Based on field evaluation of SB resistance and a genetic map constructed with 214 markers, a total of eight QTLs were identified for LH and eight QTLs for DR under three environments, respectively. The QTLs for LH were anchored on chromosomes 1, 3, 4, 5, 6, and 8, and explained 4.35-17.53% of the phenotypic variation. The SB resistance allele of qHNLH4 from TN1 decreased LH by 3.08 cm, and contributed to 17.53% of the variation at environment 1. The QTL for LH (qHZaLH8) detected on chromosome 8 in environment 2 explained 16.71% of the variation, and the resistance allele from CJ06 reduced LH by 4.4 cm. Eight QTLs for DR were identified on chromosomes 1, 5, 6, 8, 9, 11, and 12 under three conditions with the explained variation from 2.0 to 11.27%. The QTL for DR (qHZaDR8), which explained variation of 11.27%, was located in the same interval as that of qHZaLH8, both QTLs were detected in environment 2. A total of six pairs of digenic epistatic loci for DR were detected in three conditions, but no epistatic locus was observed for LH. In addition, we detected 12 QTLs for plant height (PH) in three environments. None of the PH-QTLs were co-located with the SB-QTLs. The results facilitate our understanding of the genetic basis for SB resistance in rice.

Background In the face of climate change, shifts in genetic structure and composition of terrestrial plant species are occurring worldwide. Because different genotypes of these plant species support different soil biota and soil processes, shifts in genetics are likely to have cascading effects on ecosystems. Scope We explore plant genetic effects on soil function in the context of climate change, and selection by soils, soil biota and plant-soil feedbacks. We propose categories of genetically-based plant traits that should be prioritized in research on genetic-based effects on soil processes including plant productivity and C allocation, tissue quality, plant water-use, and rhizosphere mutualisms. Additionally, we posit that soil community responses to climate change should be considered in concert with plant genotype because of sensitivity of soil communities to climate. We use two case studies to highlight these points. Conclusions We argue that the effects of climate change as an agent of selection on plants may cascade to affect soils, and ultimately the structure, composition and function of ecosystems. Understanding the ecological and evolutionary potential of plant-soil linkages may help us

Bakanae or foot rot disease caused by Fusarium fujikuroi (teleomorph: Gibberella fujikuroi, Sawada, Wollenweber) is emerging as a serious disease of rice. A simple, reliable and high-throughput method for screening the disease would enable rapid screening of germplasm aimed at identifying resistance sources, mapping QTLs/genes and developing resistant rice cultivars. In the present study, a highthroughput, reliable bioassay to screen rice germplasm for resistance to bakanae disease was developed and compared with the conventional screening technique. This technique involves soaking of rice seeds in fungal spore suspension (1.0x10 6 spores ml-1) for 24 hours at room temperature. Seedling growth at 30°/25° (±3)°C day/night temperature and 60/80(±10)% day/night relative humidity in glasshouse gave the best results. The new protocol described here produces consistent and reproducible bakanae disease symptoms and enables screening of hundreds of rice germplasm within 15 days without any loss of precision in screening of rice genotypes against bakanae disease. The resistant and susceptible genotypes can be used for developing mapping population and identification of QTLs/genes conferring resistance to bakanae disease.

Objectives: This is the first time in literature to the biosynthesis of rod-shaped myco-synthesized MnO NPs in average diameter ~35nm using extracellular bioactive metabolites of endophytic Trichoderma virens strain EG92 as capping/reducing agents and MnCl2.4H2O as a parent component. Methods: The wheat bran medium was chosen to grow endophytic strain EG92, which produced a variety of bioactive metabolites in extracellular fraction, which increases the yield of MnO NPs to 9.53 g/l. The whole medium and fungal growth conditions that influenced biomass generation were optimized as successive statistical optimization approaches (Plackett-Burman and Box-Behnken designs). Results: The production improvements were achieved at pH 5.5, WBE (35%), and inoculum size (10%), which increased Xmax to twelve-folds (89.63 g/l); thereby, Pmax increased to eight-folds (82.93 g/l). After 162 hours, Xmax (145.63 g/l) and Pmax (99.52 g/l) on the side of µmax and YX/S were determined as 0.084 and 7.65, r...

The extensive use of synthetic pesticides has a harmful impact on the environment, plants and animal health. It is a big challenge for all farming systems to develop novel approaches, which are eco-friendly and improve food quality. As compared to synthetic pesticides, the use of beneficial microbes is the best option to maintain the environmental condition because they are cost-effective and ecofriendly. In the recent era, biological antagonistic microorganisms (Trichoderma spp.) are the best approach to control the soil-borne fungal pathogens associated with plant roots of agriculturally important crops. Due to fast growth and rhizospheric colonization ability, this fungus competes with other pathogenic soil-borne fungi by producing different metabolites (volatile and non-volatile). Trichoderma protected the plants from pathogenic fungi through mycoparasitic and antibiosis capability. Furthermore, it has the ability to improve plant health by inducing SAR (Systemic acquired resist...

Nearly half of world population consumes rice as the principal food crop. Rice is affected by several seed borne pathogens. Seed treatment with chemical will pose adverse effects on the environment. The excessive use of fungicides has raised concerns such as a decrease in the fungicide sensitivity of the pathogens. For this reason, alternative methods are being investigated to control the disease. To reduce the inoculum level of seedborne pathogens in rice seeds and to improve the germination speed of the seed. Hot water treatment is one of the non chemical method can be used as an alternative strategy to control seedborne pathogens of rice but it may adversely affect germination and seedling vigour. Hence, we tested the thermotherapy at different temperatures and different times of exposures. The parameters such as germination percentage, plumule length, radicle length, total seedling length and seed vigour were recorded. Hot water treatment at 55°C for 15 minutes was physiologically safe for rice seed. The hot water treatment at 65°C for 20 minutes consistently decreased seed quality in all parameters and is considered an unsafe treatment for rice variety.

The efficient management of foliar as well as soil borne pathogens makes Trichoderma one of the most used biocontrol agents in the world. Development of formulations with enhanced shelf life and broad-spectrum activity could pave the way of rapid commercialization of these beneficial microorganisms. Two native isolates of Trichoderma species (Tr Isolate 2 and Tr Isolate 5) were collected from paddy and groundnut rhizospheres respectively. Their vigorous growth in different culture media and profound inhibitory effects on two potential soil borne pathogens namely Rhizoctonia solani and Sclerotium rolfsii as observed in dual culture experiment were the basis of selecting these two isolates among all the seven other isolates collected from different crop rhizospheres for mass production. Present study deals with evaluation of nine liquid substrates and one talc-based formulation. Colony forming units were counted following the serial dilution technique and a gradual reduction was obser...

Sheath blight (ShB) disease caused by Rhizoctonia solani is one of the major threats to rice crop worldwide. Progress in breeding for resistant rice varieties is limited due to lack of highly resistant germplasm against sheath blight. In present study, diverse rice landrace were phenotyped against R. solani and resistant and moderately resistant sources were identified from the panel of 134 germplasm pool. Landrace Nizam shait showed resistance, where as Bidar local-2, Jigguvaratiga, NavaliSali, Jaddu and Tetep exhibited moderate resistance. Population structure was analysed by genotyping the accessions using 63 genome wide Rice Microsatellite markers which divided the mapping panel into two groups. Association mapping using GLM ? Q model of TASSEL indicated significant association between twenty-one marker loci on nine chromosomes with ShB resistance with phenotypic variation (R 2) ranging 3.02-22.71 per cent. We identified 13 new markers to be associated with ShB resistance. The present work validates previously identified eight markers flanking different shB QTLs. None of the allele from the tested markers was unique and common among resistant and moderately resistant landraces identified in this work except allele 420 bp of RM337 and allele 310 bp of RM5556 noticed only in Tetep. Our findings predict the possible presence of unreported QTL region in marker interval of RM337 and RM5556 on chromosome 8 for ShB resistance in Tetep which invites further investigation.