This study examined the endosphere and rhizosphere microbiomes of wheat plants grown in soils infested with the pathogenic fungus Rhizoctonia solani and challenged with Streptomyces biocontrol agents. Wheat seeds were treated with three Streptomyces strains and planted in soils with varying levels of R. solani infestation. Over 20 weeks, 233 root and soil samples were analyzed. The microbiomes changed over time, with some bacteria and fungi increasing. Biocontrol strains promoted plant growth and modulated the root microbiome by decreasing some bacteria like Paenibacillus and increasing other microbes. Soils with highest R. solani levels had more fungal pathogens and plant disease. Application of beneficial Streptomy
Floating Row Covers Exclude Insects affecting Fall Grown Squash; Gardening Guidebook for Florida www.scribd.com/doc/239851313 ~ University of Florida, For more information, Please see Organic Edible Schoolyards & Gardening with Children www.scribd.com/doc/239851214 - Double Food Production from your School Garden with Organic Tech www.scribd.com/doc/239851079 - Free School Gardening Art Posters www.scribd.com/doc/239851159 - Increase Food Production with Companion Planting in your School Garden www.scribd.com/doc/239851159 - Healthy Foods Dramatically Improves Student Academic Success www.scribd.com/doc/239851348 - City Chickens for your Organic School Garden www.scribd.com/doc/239850440 - Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica www.scribd.com/doc/239850233 - Simple Square Foot Gardening for Schools, Teacher Guide www.scribd.com/doc/23985111 ~
This study examined the response of five tomato cultivars (Anmol, Roma v.f., Gola France, Roma, and Sunehra) to the root-knot nematode Meloidogyne incognita. When inoculated with M. incognita, root and shoot growth was significantly reduced in all tomato cultivars compared to uninoculated plants. Variation was observed among cultivars in terms of nematode multiplication and damage. Roma v.f. and Roma Holland showed greater nematode reproduction and gall formation compared to Gola France and Sunehra. Anmol exhibited the least nematode reproduction and damage. This research identified resistance levels among tomato cultivars to
Agrobacterium tumefaciens and crown gall diseaseskaushik iyer
Crown gall is a disease of plants caused by the bacterium Agrobacterium tumefaciens that affects over 1000 plant species. Symptoms include round, rough galls forming at or near the soil line on infected plants. The disease is transmitted when the bacterium enters through wounds in the plant and induces tumor formation through genes carried by its Ti plasmid. The Ti plasmid integrates a segment called T-DNA into the plant's chromosomes that directs the plant to produce compounds the bacteria uses as nutrients, genetically engineering the infected plant cell.
This document discusses entomopathogenic nematodes (EPNs) which are beneficial nematodes that can parasitize and kill insects. EPNs have a wide host range and can be used as biological control agents against many crop insect pests. They have advantages over chemical insecticides in that they are non-toxic and can be incorporated into integrated pest management programs. The document describes the life cycle and symbiotic relationship of EPNs with bacteria, as well as their mass production using wax moth larvae. It provides examples of using EPNs to control pseudostem weevil and rhizome weevil in banana crops.
Nematode effector proteins play a key role in plant parasitism. Effectors are secretory proteins that alter host cells to suppress defenses and facilitate infection. They are synthesized in gland cells and injected into plants through the stylet. Effectors can have different targets, such as modifying the cell wall, altering metabolism or hormone signaling, and suppressing immunity. Characterizing effectors provides insights into plant responses and resistance mechanisms. Recent studies have identified effectors that interact with components of auxin signaling or the NADPH oxidase complex to promote parasitism. Going forward, RNA interference targeting important nematode genes holds promise for developing resistant crop varieties.
Los días 20 y 21 de mayo de 2014, la Fundación Ramón Areces organizó el Simposio Internacional 'Microorganismos beneficiosos para la agricultura y la protección de la biosfera' dentro de su programa de Ciencias de la Vida y de la Materia.
Avs significant achievements and present status of trichoderma spp. inAMOL SHITOLE
This document summarizes a seminar presentation on the significant achievements and present status of Trichoderma spp. in biocontrol of plant diseases.
The summary includes:
1) Trichoderma spp. are filamentous fungi commonly used as biocontrol agents due to their ability to control plant pathogens through competition, mycoparasitism, and induced resistance.
2) Mutation induction using physical and chemical mutagens has been used to improve the biocontrol potential of Trichoderma spp. by impacting their morphological, biochemical, and mycoparasitic properties.
3) Studies presented show mutants exhibiting increased growth, sporulation, antibiotic production, and tolerance to stress
Floating Row Covers Exclude Insects affecting Fall Grown Squash; Gardening Guidebook for Florida www.scribd.com/doc/239851313 ~ University of Florida, For more information, Please see Organic Edible Schoolyards & Gardening with Children www.scribd.com/doc/239851214 - Double Food Production from your School Garden with Organic Tech www.scribd.com/doc/239851079 - Free School Gardening Art Posters www.scribd.com/doc/239851159 - Increase Food Production with Companion Planting in your School Garden www.scribd.com/doc/239851159 - Healthy Foods Dramatically Improves Student Academic Success www.scribd.com/doc/239851348 - City Chickens for your Organic School Garden www.scribd.com/doc/239850440 - Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica www.scribd.com/doc/239850233 - Simple Square Foot Gardening for Schools, Teacher Guide www.scribd.com/doc/23985111 ~
This study examined the response of five tomato cultivars (Anmol, Roma v.f., Gola France, Roma, and Sunehra) to the root-knot nematode Meloidogyne incognita. When inoculated with M. incognita, root and shoot growth was significantly reduced in all tomato cultivars compared to uninoculated plants. Variation was observed among cultivars in terms of nematode multiplication and damage. Roma v.f. and Roma Holland showed greater nematode reproduction and gall formation compared to Gola France and Sunehra. Anmol exhibited the least nematode reproduction and damage. This research identified resistance levels among tomato cultivars to
Agrobacterium tumefaciens and crown gall diseaseskaushik iyer
Crown gall is a disease of plants caused by the bacterium Agrobacterium tumefaciens that affects over 1000 plant species. Symptoms include round, rough galls forming at or near the soil line on infected plants. The disease is transmitted when the bacterium enters through wounds in the plant and induces tumor formation through genes carried by its Ti plasmid. The Ti plasmid integrates a segment called T-DNA into the plant's chromosomes that directs the plant to produce compounds the bacteria uses as nutrients, genetically engineering the infected plant cell.
This document discusses entomopathogenic nematodes (EPNs) which are beneficial nematodes that can parasitize and kill insects. EPNs have a wide host range and can be used as biological control agents against many crop insect pests. They have advantages over chemical insecticides in that they are non-toxic and can be incorporated into integrated pest management programs. The document describes the life cycle and symbiotic relationship of EPNs with bacteria, as well as their mass production using wax moth larvae. It provides examples of using EPNs to control pseudostem weevil and rhizome weevil in banana crops.
Nematode effector proteins play a key role in plant parasitism. Effectors are secretory proteins that alter host cells to suppress defenses and facilitate infection. They are synthesized in gland cells and injected into plants through the stylet. Effectors can have different targets, such as modifying the cell wall, altering metabolism or hormone signaling, and suppressing immunity. Characterizing effectors provides insights into plant responses and resistance mechanisms. Recent studies have identified effectors that interact with components of auxin signaling or the NADPH oxidase complex to promote parasitism. Going forward, RNA interference targeting important nematode genes holds promise for developing resistant crop varieties.
Los días 20 y 21 de mayo de 2014, la Fundación Ramón Areces organizó el Simposio Internacional 'Microorganismos beneficiosos para la agricultura y la protección de la biosfera' dentro de su programa de Ciencias de la Vida y de la Materia.
Avs significant achievements and present status of trichoderma spp. inAMOL SHITOLE
This document summarizes a seminar presentation on the significant achievements and present status of Trichoderma spp. in biocontrol of plant diseases.
The summary includes:
1) Trichoderma spp. are filamentous fungi commonly used as biocontrol agents due to their ability to control plant pathogens through competition, mycoparasitism, and induced resistance.
2) Mutation induction using physical and chemical mutagens has been used to improve the biocontrol potential of Trichoderma spp. by impacting their morphological, biochemical, and mycoparasitic properties.
3) Studies presented show mutants exhibiting increased growth, sporulation, antibiotic production, and tolerance to stress
This document discusses the identification and classification of plant viruses that can be transmitted through seeds. It provides background on how inadequate identification early on led to confusion, but the establishment of standardized criteria and rules by the ICTV has helped create order. Over 200 virus diseases are known to be seed-transmitted. The document lists the taxonomic positions of many seed-transmitted viruses and viroids according to the latest ICTV classification, organized by order, family, and genus. It also discusses the identification process for seed-transmitted viruses and how classification assessments are made.
This document discusses how organisms interact in their environment through communication. It focuses on nematodes and their use of chemical signals called semiochemicals. Nematodes have developed a sophisticated chemical language to organize their communities using pheromones, allomones, synomones and kairomones. The document examines nematode nervous systems, chemosensory organs, the role of age and other factors on attractants, and examples of nematode communication such as attraction to hosts, fungi, and responses to sex pheromones. It discusses recent research findings on quorum sensing and chemical mating cues in C. elegans.
The Production of Triploid Clariobranchus in Indoor HatcheryIOSR Journals
This study evaluated the interactive effects of rhizobium and virus inocula on three cowpea cultivars. The cultivars were inoculated with two rhizobium strains (R25B and IRj2180A) and two virus strains (CABMV and CYMV) at two different times. Viral inoculation significantly reduced nodulation, biomass production, and grain yields across all cultivars. Maximum reductions occurred without rhizobium inoculation. Early inoculation had a greater effect than late inoculation. The interaction of rhizobium and virus strains showed that viral severity was not reduced by rhizobium presence. Cultivar IT90K-277-2 performed best
Bacillus thuringiensis (Bt) is a soil-dwelling bacterium that produces crystal proteins during sporulation that have insecticidal properties. Different Bt strains produce different crystal proteins that are toxic to various insect orders. The crystals are ingested by insect larvae and the toxins bind to receptors in the gut, forming pores that cause cell death. Bt is commonly used as a biological insecticide and its genes have been inserted into genetically modified crops, providing resistance against insect pests.
Agrobacterium tumefaciens is a soil bacteria known to cause crown gall disease in plants. It has been used for genetic engineering due to its ability to transfer DNA segments (T-DNA) from its tumor-inducing plasmid into plant cells. The T-DNA can be modified to contain genes of interest. To make A. tumefaciens useful for genetic engineering, the oncogenes are removed to make it nonpathogenic while retaining its DNA transfer ability. The modified T-DNA with genes of interest is then introduced. A. tumefaciens has been used to genetically engineer many important crops like soybean, cotton, maize and produce new varieties with desirable traits.
This document summarizes a review article on the reproductive toxic effects of pyrethroid pesticides in non-target species. The review finds that pyrethroid exposure decreases fertility in both sexes by disrupting endocrine function and steroid hormone levels. It decreases sperm counts and increases fetal mortality in females mated with exposed males. Histopathological examination found abnormalities in testes, epididymis and ovaries after pyrethroid exposure. The review concludes that pyrethroids impair reproduction in animals and vitamin E may help prevent some toxic effects due to its antioxidant properties.
This document discusses insect-resistant crops, including how genes from microorganisms, plants, and animals can confer insect resistance when introduced into crop plants. It covers various types of insect-resistant crops like Bt corn, rice, and cotton that have been commercialized. While insect-resistant crops can reduce pesticide usage, some have concerns about their safety and impact. The technology continues to advance as new genes are discovered and combined to target more pests and prevent insect resistance.
Cryotherapy for Pathogen Free Planting Material in Ornamental Crops Abhay Kumar Gaurav
Cryotherapy of shoot tips is a novel technique used for pathogen eradication from plants, where sample is exposed to a low temperature (-196°C) followed by shoot tip culture. Cryotherapy of shoot tips can result in virus-free plants at a high frequency. Cryotherapy facilitates treatment of large numbers of samples because pathogen eradication by this method is independent of the size of shoot tips used.
Bacillus thrungenesis (BT) is a type of bacteria which secrete a special type of toxin which can kill specific type of pest and insects.
in case of any question contact me at zain_bbt@yahoo.com
Los días 20 y 21 de mayo de 2014, la Fundación Ramón Areces organizó el Simposio Internacional 'Microorganismos beneficiosos para la agricultura y la protección de la biosfera' dentro de su programa de Ciencias de la Vida y de la Materia.
Breeding for Major Insect Pests Resistance in RicePriyanka S
This document discusses breeding for major insect pest resistance in rice. It outlines 8 major insect pests of rice including brown planthopper and white backed plant hopper. Yield losses from these pests range from 31.5% in Asia to 2% in Europe annually. The document then discusses genetic resistance as the best method for insect control and outlines different types of genetic resistance like monogenic, oligogenic, polygenic, vertical and horizontal resistance. It also discusses mechanisms of insect resistance like non-preference, antibiosis, tolerance and avoidance. Sources of insect resistance and breeding methods are then outlined along with use of biotechnology approaches like DNA markers, transformation and wide hybridization. Specific examples of breeding for resistance to brown planth
The document discusses transgenic maize (corn) that has been genetically modified to be resistant to herbicides and pests. It focuses on Bt corn, which contains a gene from Bacillus thuringiensis that produces a toxin lethal to the European corn borer. Bt corn provides effective control of this pest with little to no impact on other insects. While Bt corn reduces yield losses and costs of control, there are concerns about the evolution of pest resistance over time.
Invitro mutation selection for biotic stresses in Plantsamvannan
In-vitro selection is a somaclonal variation method that uses a selection agent or particular condition to select for somaclones with a desired character. Various mutagens like gamma irradiation, chemicals, and transposons can be used to induce mutations in vitro. Somatic embryogenesis is advantageous for in-vitro selection as it allows treatment of large populations and rapid generation of non-chimeric plants. Chemical mutagens are commonly used for in-vitro selection due to ease of handling. In-vitro selection has been used successfully to obtain disease resistance in various crop species like tobacco, rice, wheat, and potato.
Plant Disease Resistant And Genetic EngineeringShweta Jhakhar
Study the adverse effects of different viruses and other fungal diseases on the plants and their growth. Discuss the methods e.g. plant disease resistant and genetic engineering to protect the plants.
Bacillus subtilis is a rod-shaped, Gram-positive bacterium commonly found in soil. It forms endospores that allow it to survive harsh environmental conditions. While traditionally considered an aerobe, recent studies have shown it can also grow anaerobically using various electron acceptors. B. subtilis is a model organism used to study processes like chromosome replication, cellular differentiation, and sporulation. It is also used industrially to produce secreted enzymes on a large scale.
This document summarizes a study on the development of resistance to Bt corn by the spotted stem borer (Chilo partellus) in Kenya over four generations. The study found significantly fewer surviving borers from Bt corn events expressing Cry1Ab and Cry1Ba toxins compared to non-Bt corn. There was no significant difference between the two Bt events. Additionally, there was no evidence that the borer population developed resistance to the Cry toxins over the generations studied, indicating Bt corn can effectively control this pest.
This document provides an overview of nematodes, including their tiny worm-like structure, prevalence in soils worldwide, and ability to severely impact plant growth. It describes some major genera of plant-parasitic nematodes found in the US, such as root-knot, cyst, and lesion nematodes, and the symptoms and damage they cause, such as root galling, stunting, and wilting. The document also notes nematodes have a wide host range and discusses some of their soil and climate preferences that influence their populations.
This document discusses the role of plant growth-promoting rhizobacteria (PGPR) in plant health promotion. It defines rhizosphere as the soil area surrounding a plant's root that is influenced by root activity and microbial processes. PGPR are beneficial bacteria that colonize plant roots and improve plant growth. They can fix nitrogen, solubilize phosphorus, produce siderophores, volatile organic compounds, indole-3-acetic acid, and ACC deaminase to facilitate nutrient uptake and stress tolerance in plants. PGPR also produce antibiotics that act as biocontrol agents against phytopathogenic bacteria, fungi and other pathogens. Inoculation of seeds and soil with PGPR can reduce the use of fertil
Bt technology uses genes from Bacillus thuringiensis to produce insecticidal crystal proteins in transgenic crops. There are several biosafety concerns regarding risks to human health from toxicity or allergies, as well as risks to the environment from increased insect resistance, gene flow to weeds or soil organisms, and effects on biodiversity. Regulatory agencies in India require various levels of approval from institutional biosafety committees, the Review Committee on Genetic Manipulation, and the Genetic Engineering Approval Committee, depending on the type and scale of field trials or commercial releases of Bt crops.
Management of root knot nematode affecting banana crop by using organic amend...Alexander Decker
1) The study evaluated the effectiveness of various organic amendments and biological products (Biocompost, Ricinus communis Powder, their combination, and Paecilomyces lilacinus-based bionematicide) against the root knot nematode Meloidogyne javanica affecting banana crops.
2) All the treatments significantly reduced nematode density and gall index, and improved plant growth compared to the control. Ricinus communis powder was the most effective at suppressing the nematode population and enhancing plant growth.
3) The treatments likely reduced nematodes through multiple mechanisms including nematicidal compounds released during decomposition and increased beneficial microorganisms in the soil. Ricinus communis contains toxic
Inheritance of stem rust (Puccinia graminis Pers. F. Sp. Tritici ericks and E...Innspub Net
Stem rust disease caused by Puccinia graminis f.sp. tritici (Pgt) is currently one of the major biotic constraints in wheat (Triticum aestivum) production worldwide. Therefore, objectives of this study were (i) to identify resistant wheat lines with both adult plant resistance (APR) and seedling plant resistance (SPR), and (ii) to determine the kind of resistance to stem rust in KSL18, PCB52, PCB62 and PCB76 wheat lines. A collection of 100 wheat lines was evaluated in the field and greenhouse for stem rust resistance. The following four lines- KSL18, PCB52, PCB62 and PCB76 were identified as resistant and were crossed with known susceptible cultivars Kwale and
Duma. The resulting F1 hybrids and F2 populations alongside the parents were then tested in the greenhouse for response to the stem rust race TTKST. The selected wheat lines exhibited infection types ‘;’ to ‘2’ depicting resistance while Kwale and Duma depicted infection type ‘3+’ to TTKST. In the F2 populations evaluations that derived from Kwale × PCB52 indicated that the resistance is conferred by a single dominant gene. However, all other F2 populations showed that the resistance was conferred by two genes complementing each other (duplicate recessive epistasis) thus the ratios 9R: 7S. These identified resistant lines could be evaluated for other qualities and passed as potential varieties or used as sources of valuable stem rust resistance. Get more articles at: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/
Identification of Ralstonia Solanacearum in Kyrgyzstan’s Potato Fields and th...Agriculture Journal IJOEAR
Abstract— In this study, we have used well-known, efficient methods and bioassay for systematic screening of R. solanacearum for identification of its phenotype and biochemical profile, as well as for pathogenicity and virulence. As a result, an aggressive race — Biovar 3 — was most isolated from the potato fields of the Issyk-Kul region, especially in fields where the Picasso variety was grown. The isolated indigenous strains of Streptomyces diastatochromogenesstrain sk-6 and Streptomyces bambergiensis strain k1-3 has the potential to be used as a biocontrol agent for the management of the bacterial wilt of potatoes, as indicated by the reduced percentage wilt incidence. Root zone and soil application of Streptomyces diastatochromogenesstrain sk-6 and Streptomyces bambergiensis strain k1-3 at a dose of 108 cell/ml significantly reduced disease incidence and increased the growth of potato plants. The disease’s progress was reduced by 60% and 56% in plants inoculated with Streptomyces diastatochromogenesstrain sk-6 and Streptomyces bambergiensis strain k1-3, respectively.
This document discusses the identification and classification of plant viruses that can be transmitted through seeds. It provides background on how inadequate identification early on led to confusion, but the establishment of standardized criteria and rules by the ICTV has helped create order. Over 200 virus diseases are known to be seed-transmitted. The document lists the taxonomic positions of many seed-transmitted viruses and viroids according to the latest ICTV classification, organized by order, family, and genus. It also discusses the identification process for seed-transmitted viruses and how classification assessments are made.
This document discusses how organisms interact in their environment through communication. It focuses on nematodes and their use of chemical signals called semiochemicals. Nematodes have developed a sophisticated chemical language to organize their communities using pheromones, allomones, synomones and kairomones. The document examines nematode nervous systems, chemosensory organs, the role of age and other factors on attractants, and examples of nematode communication such as attraction to hosts, fungi, and responses to sex pheromones. It discusses recent research findings on quorum sensing and chemical mating cues in C. elegans.
The Production of Triploid Clariobranchus in Indoor HatcheryIOSR Journals
This study evaluated the interactive effects of rhizobium and virus inocula on three cowpea cultivars. The cultivars were inoculated with two rhizobium strains (R25B and IRj2180A) and two virus strains (CABMV and CYMV) at two different times. Viral inoculation significantly reduced nodulation, biomass production, and grain yields across all cultivars. Maximum reductions occurred without rhizobium inoculation. Early inoculation had a greater effect than late inoculation. The interaction of rhizobium and virus strains showed that viral severity was not reduced by rhizobium presence. Cultivar IT90K-277-2 performed best
Bacillus thuringiensis (Bt) is a soil-dwelling bacterium that produces crystal proteins during sporulation that have insecticidal properties. Different Bt strains produce different crystal proteins that are toxic to various insect orders. The crystals are ingested by insect larvae and the toxins bind to receptors in the gut, forming pores that cause cell death. Bt is commonly used as a biological insecticide and its genes have been inserted into genetically modified crops, providing resistance against insect pests.
Agrobacterium tumefaciens is a soil bacteria known to cause crown gall disease in plants. It has been used for genetic engineering due to its ability to transfer DNA segments (T-DNA) from its tumor-inducing plasmid into plant cells. The T-DNA can be modified to contain genes of interest. To make A. tumefaciens useful for genetic engineering, the oncogenes are removed to make it nonpathogenic while retaining its DNA transfer ability. The modified T-DNA with genes of interest is then introduced. A. tumefaciens has been used to genetically engineer many important crops like soybean, cotton, maize and produce new varieties with desirable traits.
This document summarizes a review article on the reproductive toxic effects of pyrethroid pesticides in non-target species. The review finds that pyrethroid exposure decreases fertility in both sexes by disrupting endocrine function and steroid hormone levels. It decreases sperm counts and increases fetal mortality in females mated with exposed males. Histopathological examination found abnormalities in testes, epididymis and ovaries after pyrethroid exposure. The review concludes that pyrethroids impair reproduction in animals and vitamin E may help prevent some toxic effects due to its antioxidant properties.
This document discusses insect-resistant crops, including how genes from microorganisms, plants, and animals can confer insect resistance when introduced into crop plants. It covers various types of insect-resistant crops like Bt corn, rice, and cotton that have been commercialized. While insect-resistant crops can reduce pesticide usage, some have concerns about their safety and impact. The technology continues to advance as new genes are discovered and combined to target more pests and prevent insect resistance.
Cryotherapy for Pathogen Free Planting Material in Ornamental Crops Abhay Kumar Gaurav
Cryotherapy of shoot tips is a novel technique used for pathogen eradication from plants, where sample is exposed to a low temperature (-196°C) followed by shoot tip culture. Cryotherapy of shoot tips can result in virus-free plants at a high frequency. Cryotherapy facilitates treatment of large numbers of samples because pathogen eradication by this method is independent of the size of shoot tips used.
Bacillus thrungenesis (BT) is a type of bacteria which secrete a special type of toxin which can kill specific type of pest and insects.
in case of any question contact me at zain_bbt@yahoo.com
Los días 20 y 21 de mayo de 2014, la Fundación Ramón Areces organizó el Simposio Internacional 'Microorganismos beneficiosos para la agricultura y la protección de la biosfera' dentro de su programa de Ciencias de la Vida y de la Materia.
Breeding for Major Insect Pests Resistance in RicePriyanka S
This document discusses breeding for major insect pest resistance in rice. It outlines 8 major insect pests of rice including brown planthopper and white backed plant hopper. Yield losses from these pests range from 31.5% in Asia to 2% in Europe annually. The document then discusses genetic resistance as the best method for insect control and outlines different types of genetic resistance like monogenic, oligogenic, polygenic, vertical and horizontal resistance. It also discusses mechanisms of insect resistance like non-preference, antibiosis, tolerance and avoidance. Sources of insect resistance and breeding methods are then outlined along with use of biotechnology approaches like DNA markers, transformation and wide hybridization. Specific examples of breeding for resistance to brown planth
The document discusses transgenic maize (corn) that has been genetically modified to be resistant to herbicides and pests. It focuses on Bt corn, which contains a gene from Bacillus thuringiensis that produces a toxin lethal to the European corn borer. Bt corn provides effective control of this pest with little to no impact on other insects. While Bt corn reduces yield losses and costs of control, there are concerns about the evolution of pest resistance over time.
Invitro mutation selection for biotic stresses in Plantsamvannan
In-vitro selection is a somaclonal variation method that uses a selection agent or particular condition to select for somaclones with a desired character. Various mutagens like gamma irradiation, chemicals, and transposons can be used to induce mutations in vitro. Somatic embryogenesis is advantageous for in-vitro selection as it allows treatment of large populations and rapid generation of non-chimeric plants. Chemical mutagens are commonly used for in-vitro selection due to ease of handling. In-vitro selection has been used successfully to obtain disease resistance in various crop species like tobacco, rice, wheat, and potato.
Plant Disease Resistant And Genetic EngineeringShweta Jhakhar
Study the adverse effects of different viruses and other fungal diseases on the plants and their growth. Discuss the methods e.g. plant disease resistant and genetic engineering to protect the plants.
Bacillus subtilis is a rod-shaped, Gram-positive bacterium commonly found in soil. It forms endospores that allow it to survive harsh environmental conditions. While traditionally considered an aerobe, recent studies have shown it can also grow anaerobically using various electron acceptors. B. subtilis is a model organism used to study processes like chromosome replication, cellular differentiation, and sporulation. It is also used industrially to produce secreted enzymes on a large scale.
This document summarizes a study on the development of resistance to Bt corn by the spotted stem borer (Chilo partellus) in Kenya over four generations. The study found significantly fewer surviving borers from Bt corn events expressing Cry1Ab and Cry1Ba toxins compared to non-Bt corn. There was no significant difference between the two Bt events. Additionally, there was no evidence that the borer population developed resistance to the Cry toxins over the generations studied, indicating Bt corn can effectively control this pest.
This document provides an overview of nematodes, including their tiny worm-like structure, prevalence in soils worldwide, and ability to severely impact plant growth. It describes some major genera of plant-parasitic nematodes found in the US, such as root-knot, cyst, and lesion nematodes, and the symptoms and damage they cause, such as root galling, stunting, and wilting. The document also notes nematodes have a wide host range and discusses some of their soil and climate preferences that influence their populations.
This document discusses the role of plant growth-promoting rhizobacteria (PGPR) in plant health promotion. It defines rhizosphere as the soil area surrounding a plant's root that is influenced by root activity and microbial processes. PGPR are beneficial bacteria that colonize plant roots and improve plant growth. They can fix nitrogen, solubilize phosphorus, produce siderophores, volatile organic compounds, indole-3-acetic acid, and ACC deaminase to facilitate nutrient uptake and stress tolerance in plants. PGPR also produce antibiotics that act as biocontrol agents against phytopathogenic bacteria, fungi and other pathogens. Inoculation of seeds and soil with PGPR can reduce the use of fertil
Bt technology uses genes from Bacillus thuringiensis to produce insecticidal crystal proteins in transgenic crops. There are several biosafety concerns regarding risks to human health from toxicity or allergies, as well as risks to the environment from increased insect resistance, gene flow to weeds or soil organisms, and effects on biodiversity. Regulatory agencies in India require various levels of approval from institutional biosafety committees, the Review Committee on Genetic Manipulation, and the Genetic Engineering Approval Committee, depending on the type and scale of field trials or commercial releases of Bt crops.
Management of root knot nematode affecting banana crop by using organic amend...Alexander Decker
1) The study evaluated the effectiveness of various organic amendments and biological products (Biocompost, Ricinus communis Powder, their combination, and Paecilomyces lilacinus-based bionematicide) against the root knot nematode Meloidogyne javanica affecting banana crops.
2) All the treatments significantly reduced nematode density and gall index, and improved plant growth compared to the control. Ricinus communis powder was the most effective at suppressing the nematode population and enhancing plant growth.
3) The treatments likely reduced nematodes through multiple mechanisms including nematicidal compounds released during decomposition and increased beneficial microorganisms in the soil. Ricinus communis contains toxic
Inheritance of stem rust (Puccinia graminis Pers. F. Sp. Tritici ericks and E...Innspub Net
Stem rust disease caused by Puccinia graminis f.sp. tritici (Pgt) is currently one of the major biotic constraints in wheat (Triticum aestivum) production worldwide. Therefore, objectives of this study were (i) to identify resistant wheat lines with both adult plant resistance (APR) and seedling plant resistance (SPR), and (ii) to determine the kind of resistance to stem rust in KSL18, PCB52, PCB62 and PCB76 wheat lines. A collection of 100 wheat lines was evaluated in the field and greenhouse for stem rust resistance. The following four lines- KSL18, PCB52, PCB62 and PCB76 were identified as resistant and were crossed with known susceptible cultivars Kwale and
Duma. The resulting F1 hybrids and F2 populations alongside the parents were then tested in the greenhouse for response to the stem rust race TTKST. The selected wheat lines exhibited infection types ‘;’ to ‘2’ depicting resistance while Kwale and Duma depicted infection type ‘3+’ to TTKST. In the F2 populations evaluations that derived from Kwale × PCB52 indicated that the resistance is conferred by a single dominant gene. However, all other F2 populations showed that the resistance was conferred by two genes complementing each other (duplicate recessive epistasis) thus the ratios 9R: 7S. These identified resistant lines could be evaluated for other qualities and passed as potential varieties or used as sources of valuable stem rust resistance. Get more articles at: http://www.innspub.net/volume-7-number-4-october-2015-ijaar/
Identification of Ralstonia Solanacearum in Kyrgyzstan’s Potato Fields and th...Agriculture Journal IJOEAR
Abstract— In this study, we have used well-known, efficient methods and bioassay for systematic screening of R. solanacearum for identification of its phenotype and biochemical profile, as well as for pathogenicity and virulence. As a result, an aggressive race — Biovar 3 — was most isolated from the potato fields of the Issyk-Kul region, especially in fields where the Picasso variety was grown. The isolated indigenous strains of Streptomyces diastatochromogenesstrain sk-6 and Streptomyces bambergiensis strain k1-3 has the potential to be used as a biocontrol agent for the management of the bacterial wilt of potatoes, as indicated by the reduced percentage wilt incidence. Root zone and soil application of Streptomyces diastatochromogenesstrain sk-6 and Streptomyces bambergiensis strain k1-3 at a dose of 108 cell/ml significantly reduced disease incidence and increased the growth of potato plants. The disease’s progress was reduced by 60% and 56% in plants inoculated with Streptomyces diastatochromogenesstrain sk-6 and Streptomyces bambergiensis strain k1-3, respectively.
Rufus Akinrinlola is a PhD candidate researching plant-microbe interactions. His work has included identifying the black pod pathogen of cocoa in Nigeria (Phytophthora megakarya), surveying nematode populations across Tennessee fields (finding high levels of soybean cyst, lesion, and root knot nematodes), and identifying Bacillus strains that promote corn growth in greenhouse studies (with increases up to 215% in shoot weight). Understanding beneficial and pathogenic plant-microbe relationships can help improve crop productivity to meet rising global food demand.
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Decoding Wheat Endosphere– Rhizosphere Microbiomes in Rhizoctonia solani – Infested Soils Challenged by Streptomyces Biocontrol Agents
1. Decoding Wheat Endosphere– Rhizosphere Microbiomes in
Rhizoctonia solani – Infested Soils Challenged by Streptomyces
Biocontrol Agents.
2. Abstract
The endosphere and the rhizosphere are pertinent milieus with microbial communities that perturb the
agronomic traits of crop plants through beneficial or detrimental interactions. In this study, they challenged these
communities by adding Streptomyces biocontrol strains to wheat seeds in soils with severe Rhizoctonia solani
infestation. Wheat plants were grown in a glasshouse standardized system, and the bacterial and fungal microbiomes of
233 samples of wheat roots (endosphere) and rhizosphere soils were monitored for 20 weeks from seed to mature plant
stage. The results showed highly dynamic and diverse microbial communities that changed over time, with
Sphingomonas bacteria, Aspergillus, Dipodascus and Trichoderma fungi increasing over time. Application of biocontrol
Streptomyces strains promoted plant growth and maturation of wheat heads and modulated the root microbiome,
decreasing Paenibacillus and increasing other bacterial and fungal OTUs. The soils with the highest levels of R. solani
had increased reads of Thanatephorus (Rhizoctonia anamorph) and increased root disease levels and increased
Balneimonas, Massilia, Pseudomonas and unclassified Micrococcaceae. As enter the era of biologically sustainable
agriculture, it may be possible to reduce and limit the effects of serious fungal infestations by promoting a beneficial
microbiome through the application of biocontrol agents during different periods of plant development.
3. Introduction
N.E. Borlaug
• Wheat is the first and foremost staple food crop in the world
• It contributes 40% of cereal food production
• World Production of wheat is 774 Million Tonnes (MT)
(FAOSTAT, 2018)
• Development of healthy societies and has supported
economic and social stability
4. Wheat root rot- Rhizoctonia solani
(Thanatephorus cucmeris)
Disintegration of root
Spindle lesion formed
at collar region
Sclerotia
Bare patches
5. Systematic Classification
Domain – Eukarya
Kingdom – Fungi
Phylum – Basidiomycota
Class- Agaricomycetes
Order - Cantharellales
Family – Ceratobasidiaceae
Genus – Rhizoctonia
Species - solani (Krik et al., 2011)
6. Rhizosphere
Region of soil around the
root surface (1-5mm)
Place where contains
maximum microbial diversity compares
non rhizosphere soils
Rhizoplane
Rhizoplane
microorganisms are found on the
surface of plant roots.
‘R-E Sphere’
7.
8. Use of living organism(macro/micro) to
suppress the population of harmful or
pathogenic organisms.
Biocontrol
9. Techniques used in this study
Illumina Sequencing
High throughput DNA SequencingTechnique.
Employs Micro and Nanotechnologies
Reduce sample size low Reagent cost less
Massive parallel sequencing
Sequence the thousands of sequences at once.
Produce enormous amount of data.
10. Flow cell
Flow cell is a base cell which made up of several lawn and it contained millions and millions
of adaptor (short oligonucleotide around 10-15 nucleotides long)
Function – Sheared DNA which binds to the surface and it leads to upcoming procedure of
sequencing
Flow cell
Lawn
Adaptor
11. Steps used – Illumina Sequencing
Sample Preparation
Cluster Generation
Sequencing
Data analysis
14. Materials and Methods
Bulk soil was collected from top 10cm of 100m2 at Waikerie, South Australia (34°14’32.91”S, 140°
5’44.31”E) (Majorly Rhizoctonia sp. infested soil)
Soil was air dried and sieved to < 2mm prior to use of pot bioassay
Pots were prepared based on testing time - 600g for 4 weeks, 1000g for 8 weeks, 1125g for 12
weeks, 2000g for 16 weeks, and 4800g for 20 weeks.
Pot Bioassays in Glasshouse
15. Wheat seeds were treated with Streptomyces sp. strains as F5, F11 and EN16 by using xanthan
gum.
Then, sowing was taken the pot and carefully separate the pot based on testing time (4th,8th ,12th,
16th and 20th week)
BCA treatments and soil infestation levels were run with four independent replicates arranged in a
randomized complete block design.
Half of bioassay pots were artificially made Rhizoctonia sp. infestation.
16. At a time of harvesting, also record the disease incidence of root rot on seminal and nodal region of
roots using a 0–5 disease scale (0 = healthy roots,5 = highly diseased and damaged roots.
At 4, 8, 12, 16, and 20 weeks, plants were carefully harvest, samples were collected from
rhizosphere soil, either seminal or nodal roots for microbiome bioassay
17. Design of Experiment
Randomized Complete Block Design
4th Week N.S. + BCA1 N.S. + BCA3 N.S. + BCA2 N.S. + Control
R. solani infested
soil + BCA 3
R. solani infested
soil + BCA 2
R. solani infested
soil + BCA 1
R. solani infested
soil + control seed
8th Week N.S. + BCA2 N.S. + BCA 1 N.S. + BCA 3 N.S. + Control
R. solani infested
soil + BCA 1
R. solani infested
soil + BCA 3
R. solani infested
soil + BCA 2
R. solani infested
soil + control seed
12th Week N.S. + BCA3 N.S. + BCA 2 N.S. + BCA 1 N.S. + Control
R. solani infested
soil + BCA 1
R. solani infested
soil + BCA 2
R. solani infested
soil + BCA 3
R. solani infested
soil + control seed
16th Week N.S. + BCA3 N.S. + BCA 1 N.S. + BCA 2 N.S. + Control
R. solani infested
soil + BCA 3
R. solani infested
soil + BCA 2
R. solani infested
soil + BCA 1
R. solani infested
soil + control seed
20th Week N.S. + BCA3 N.S. + BCA 1 N.S. + BCA 2 N.S. + Control
R. solani infested
soil + BCA 1
R. solani infested
soil + BCA 3
R. solani infested
soil + BCA 2
R. solani infested
soil + control seed
Abbreivation
N.S. = Native soil (Waikerie, South
Austra.)
BCA 1 = Streptomyces sp. strain F5
BCA 2 = Streptomyces sp. strain F11
BCA 3 = Streptomyces sp. strain EN16
18. DNA Extraction and sequencing
Collection of 16 random samples of root, rhizosphere and seeds of wheat plant
Each sample were subjected to CTAB DNA Extraction. Obtained final DNA was
suspended in TE buffer
Polymerase chain reaction (PCR) was performed by following standards = 35 cycles
of 95°C @ 30 s; 58°C @30 s; and 72°C @60s by using KAPA HiFi PCR
Thermocycler
19. Primers prepared from
a)from bacterial community targeted the V3–V4 regions of the 16S rRNA genes with 341F and
806R primers
b)the fungal community that targeted the ITS1 region with ITS1F and ITS2F primers
After PCR, Samples were pooled and proceed the next step (i.e.) Sequencing by using Illumina
MiSeq System and analysis the variance.
Sequences are categorized and arranged into defined the OTUs of reference species.
21. Results
i) The Microbiomes Endosphere and Rhizosphere of wheat crops change over time in a
predictable manner, even in soils with severe Rhizoctonia infestation
• Total 1213983 bacteria and 793412 fungal sequences were identified
• Those sequence were organized into 6880 bacterial and 861 fungal OTU’s
• These sequences consisted of 628 bacterial and 204 fungal taxa (assigned at the genus)
• A set of 16 genera of bacteria and 7 fungi were found in all samples. (i.e.)
Agrobacterium, Pseudomonas, Streptomyces, Fusarium etc.
23. Agglomerative (Bottom up approach) cluster shows maximum diversity
present in rhizosphere soil, followed by roots and then seeds
Rhizosphere soil > Roots > Seeds
25. In this experiment, strain F5 did not perform well , it
showed as similar like control plants, but strains EN16
and F11 gave positive results
• higher biomass at later stages,
• earlier formation of wheat heads and
• lower root disease indexes (more evident with EN16-
coated seeds)
20 weeks
Impact of biocontrol Streptomyces strains on Rhizoctonia sp. and Other OTU’s.
16 weeks
26. Disease incidence index
Grade Description
0 No infection observed
1 Lesion limited to lower 20% of the height of the plant
2 Lesion limited to 21-30% of the height of the plant
3 Lesion limited to 31-45% of the height of the plant
4 Lesion limited to 46-65% of the height of the plant
5 Lesion limited to more than 65% of the height of the
plant
27. Table S1
Rhizoctonia-disease
severity
Waikerie soil + control seed 2.4 ± 0.79
Waikerie soil + seed with F11 2.7 ± 0.75
Waikerie soil + seed with EN16 1.9 ± 0.62
Waikerie soil + seed with F5 2.4 ± 0.52
Waikerie R. solani infested soil + control seed 4.4 ± 0.48
Waikerie R. solani infested soil + seed with F11 4.7 ± 0.11
Waikerie R. solani infested soil + seed with EN16 3.9 ± 0.10
Waikerie R. solani infested soil +seed with F5 4.7 ± 0.83
Tables S1, S2 and S3 show the values of Rhizoctonia disease severity at 4 weeks, weight per plant at 16
weeks and wheat heads per pot at 20 weeks, respectively.
28. Table S2 Weight per plant (mg) at
16 weeks
Waikerie soil + control seed 483 ± 51.0
Waikerie soil + seed with F11 602 ± 158.9
Waikerie soil + seed with EN16 615 ± 51.4
Waikerie soil + seed with F5 515 ± 138.7
Waikerie R. solani infested soil + control seed 571 ± 146.9
Waikerie R. solani infested soil + seed with F11 560 ± 150.3
Waikerie R. solani infested soil + seed with EN16 590 ± 123.6
Waikerie R. solani infested soil +seed with F5 558 ± 34.4
Biomass calculation
29. Table S3 Wheat heads at 20 weeks (average per
pot)
Waikerie soil + control seed 4.5 ± 0.5
Waikerie soil + seed with F11 4.0 ± 0.4
Waikerie soil + seed with EN16 5.3 ± 0.9
Waikerie soil + seed with F5 4.0 ± 0.7
Waikerie R. solani infested soil + control seed 3.3 ± 0.3
Waikerie R. solani infested soil + seed with F11 4.3 ± 0.5
Waikerie R. solani infested soil + seed with EN16 4.75 ± 0.9
Waikerie R. solani infested soil +seed with F5 3.5 ± 0.9
Wheat heads per pot
31. • Root rot percent
disease incidence
maximum at the 4th
week
• It decreased in the
subsequent weeks
because of increase of
strains of streptomyces
sp.
32. Taxonomic similarity (%) comparing control versus biocontrol-treated roots; taxonomic groups observed in
roots obtained from low and high Rhizoctonia-level soils were also compared.
Control vs.
F11
Control vs.
EN16
Control vs.
F5
Low vs. high
Rhizoctonia
4 weeks 63 64 48 43
8 weeks 88 88 88 88
12 weeks 59 54 69 53
16 weeks 71 44 69 51
20 weeks 67 46 60 36
Bray Curtis
Similarities
and
ANOSIM
analysis
33. The addition of Streptomyces strains F11 and EN16 affected mostly Paenibacillus populations,
reducing their relative abundance drastically over the 4th weeks.
34. Conclusion
• Microbiomes from rhizosphere and endosphere were constantly change over the time.
• Streptomyces sp. strains (EN16 and F11 ) was effective biocontrol of Rhizoctonia solani
• Streptomyces sp. have a ability to cause a shift over microbiomes population. For eg. Streptomyces
sp. affected the microbiome of Paenibacillus sp.
35. Future Prospectus
• Ability of Streptomyces strain to modify rhizosphere and endosphere microbiome can be harnessed for
improving microbiomes in other staple crops as well.
• Apart from its biocontrol activity, the strain can be checked for its plant growth promoting traits and used
as biofertilizer.
• Optimization of its performance under field conditions need to be validated.
37. References
• Anderson, M., Ellingsen, K., and McArdle, B. (2006). Multivariate dispersion
as a measure of beta diversity. Ecol. Lett. 9, 683–693. doi: 10.1111/j.1461-
0248.2006.00926.x
• Reinhold-Hurek, B., Bünger, W., Burbano, C., Sabale, M., and Hurek, T.
(2015). Roots shaping their microbiome: global hotspots for microbial activity.
Annu Rev. Phytopathol. 53, 403–424. doi: 10.1146/annurev-phyto082712-102342
• Roget, D. (1995). Decline in root rot (Rhizoctonia solani AG-8) in wheat in a
tillage and rotation experiment at Avon, South Australia. Austral. J. Exp. Agric.
35, 1009–1013. doi: 10.1071/EA9951009
• Sabaratnam, S., and Traquair, J. A. (2002). Formulation of a Streptomyces
biocontrol agent for the suppression of Rhizoctonia Damping-off in tomato
transplants. Biol. Control 23, 245–253. doi: 10.1006/bcon.2001.1014