Download or read book An Evaluation of Protocols for Stabilizing Pathotypes of Phytophthora Sojae Isolates and Characterizing Race specific Resistant Genes in Soybean Plant Introductions written by Hongtao Jia and published by . This book was released on 2003 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phytophthora sojae isolates that have stable pathotypes (virulence formulae) and high levels of aggressiveness are needed to identify resistance genes (Rps). Pathotypes of P. sojae isolates are designated based on a set of standard soybean differentials carrying different Rps genes. In this study, protocols were evaluated for isolates collected from the field to reduce or eliminate variability in pathotype reaction from successive single-zoospores and single-oospores. Isolates of P. sojae representing races 1, 3, 4, 7, and 25 from IN and OH were also compared on three separate sets of soybean differentials using three separate seed sources. Substantial variation in the pathotypes was found in single-zoospores both within a generation and successive generations. P. sojae races 1, 3, 4, 7, and 25 from IN and OH had the expected reaction on all three sets of differentials for Rps1b, Rps1c, Rps1k, Rps2, Rps3a, Rps4, Rps5, Rps7, and on the differential Harlon, L59-731 and Union for Rps1a. Differentials L88-8470 for Rps1a and L93-3312 for Rps1d did not have the expected response. Additional races are needed to differentiate reactions on Rps3b, Rps3c, and Rps6. Utilizing different sources of resistance for Rps alleles may also account for some of the differences in reactions among P. sojae isolates. Incorporating race-specific resistant genes (Rps) to Phytophthora sojae into modern soybean cultivars is the major management strategy for controlling Phytophthora damping-off, root and stem rot disease. Some plant introductions (PIs) from China were identified that were resistant to P. sojae isolates R7, R17 and R25. Two accessions PI567.642A and PI567.550 were among these PIs. They were crossed with soybean differentials to determine which Rps alleles were present in these PIs. F2:3 lines of these two PIs with Williams and Harosoy segregated in 15 resistant to 1 susceptible following inoculation with race 1 which indicates both PIs have two Rps genes. These F2:3 lines as well as other populations were then evaluated with 9 P. sojae isolates to determine which Rps gene(s) may be present. For PI567.642A X Williams population, a 3 resistant to 1 susceptible segregation ratio in F2:3 lines for both R17 and R25 was identified. Following inoculation of these lines with R2, R3, R4, R7, a 15 resistant to 1 susceptible segregation ratio was found. For PI567.550, there was a 3 resistant to 1 susceptible segregation ratio following inoculation of F2:3 lines of PI567.550 X Harosoy 63 (Rps1a) with R3 which indicates PI567.550 has Rps1a. A 3 resistant to 1 susceptible segregation ratio was also found following inoculation of F2:3 populations of PI567.550 X Harosoy (Rps7), PI567.550 X Haro4272 (Rps4), PI567.550 X Haro5272 (Rps5), PI567.550 X Haro6272 (Rps6) with R17. In addition, both PI567.550 and PI567.642A are resistant to R30-T, R31 and susceptible to R20. Based on the inoculation data, we proposed that PI567.642A has Rps1k plus Rps3b and PI567.550 has Rps1a and Rps3b.
Download or read book Reactions of Soybean Plant Introductions PI273483 to PI427107 Following Inoculation with Phytophthora Sojae written by Anne Elizabeth Dorrance and published by . This book was released on 2001 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Genome wide Analyses for Partial Resistance to Phytophthora Sojae Kaufmann and Gerdemann in Soybean glycine Max L Merr Populations from North America and the Republic of Korea written by Rhiannon N. Schneider and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Phytophthora root and stem rot of soybean (Glycine max) is caused by the oomycete pathogen Phytophthora sojae. This disease can be controlled by genetic resistance, but can cause devastating yield losses in fields planted with susceptible soybean cultivars and results in losses of around $300 million annually in the US. Partial resistance is considered to be more durable against P. sojae than race-specific resistance conferred by Rps genes and is theoretically effective against all races of this pathogen. Evaluation of a historical set of public cultivars representing 80 years of soybean breeding indicated that there have been genetic gains for partial resistance; however, these gains may have begun to plateau in the 1970s to early 1980s. Cultivars developed in Ohio generally have high levels of partial resistance to P. sojae; however, there is little known about the genetic regions associated with the partial resistance. Further improvement of increasing partial resistance could be achieved through the introgression of known quantitative trait loci (QTL) from plant introductions from the Republic of Korea (South Korea), which contain high levels of partial resistance. From an analysis of 1,398 plant introductions with a wide range of phenotypic expression of resistance, sixteen single nucleotide polymorphisms (SNPs) were associated with partial resistance to P. sojae. These SNPs were located in three genomic regions, or QTL, on chromosomes 3, 13, and 19. The QTL on chromosome 19 represented a novel locus, whereas the QTL on chromosomes 3 and 13 were coincident with previously identified QTL for partial resistance and/or Rps genes. In contrast, a genome-wide association study carried out in Ohio breeding lines was unable to detect any significant marker-trait associations, limiting the ability to use marker assisted selection to improve partial resistance in this population. However, genomic selection (GS) was shown to be a promising means of selection, with efficiencies relative to phenotypic selection of 0.5 to 1. Importantly, GS can be implemented through use of multi-trait indices which include yield. As exotic germplasm with high levels of partial resistance are identified, GS may be a valuable tool for utilizing exotic sources of partial resistance to P. sojae while maintaining or improving yield.
Download or read book Mapping Multiple Novel Race specific Resistance Genes for Phytophthora Sojae in Soybean PI 408211B written by Zhifen Zhang and published by . This book was released on 2009 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Phytophthora sojae is one of the most destructive soybean pathogens. Thus far, fourteen race-specific resistance genes (Rps) towards P. sojae have been identified, however new pathotypes have emerged as they were deployed. In response to the emergence of many new pathotypes, novel Rps genes need to be identified. PI 408211B was proposed as a source of novel resistance genes for P. sojae. The objective of this study was to map one locus for resistance to isolate OH17 (vir. 1b, 1d, 2, 3a, 3b, 3c, 4, 5, 6 and 7) and the three candidate genomic regions for resistance to isolate OH25 (vir. 1a, 1b, 1c, 1k and 7). In three separate mapping populations, resistance to OH17 was mapped to Rps1 region on chromosome 3 where there is a R-gene cluster with simple sequence repeat (SSR) and single nucleotide polymorphisms (SNPs) markers. The resistance locus for OH17 was flanked by SSR markers GM3093 and GM3203, both with a genetic distance of 2.1cM from the locus, but the allelism test for this locus to Rps1 was unsuccessful. Bulk segregant analysis (BSA) was used to identify three loci for resistance to OH25 in a Stressland x PI 408211B BC4F2:7 population. Twelve DNA pools each with sixteen to twenty resistant individuals and a DNA pool of all susceptible individuals were screened with two hundred and nineteen SSR markers covering twenty chromosomes. The results of the BSA indicated that the resistance to OH25 in PI408211B was conferred by novel loci as SSR markers previously linked with known Rps locus were not associated with the resistance. In addition, ten homozygous resistant isolines were selected from this population and screened with eight hundred and eighty SNP markers to detect introgressions from PI 408211B potentially carrying novel resistance loci. Two putative loci were identified by BSA and single marker association analysis. One region tagged with Sat_044 and its adjacent markers on chromosome 9 (MLG K) associated with resistance to OH25 was identified in Stressland x PI 408211B BC4F2:7, Strong x PI 408211B BC4F2:3 and PI 408211B x Williams F4:6. Another region tagged with Satt660 and Satt549 on chromosome 3 (MLG N) associated with resistance to OH25 was identified through single marker association analysis in PI 408211B x Williams F4:5, and one introgression of PI 408211B was detected close to that region in Strong x PI 408211B BC4F2:3. Efforts were made to identify an isolate to which only one of these three loci conferred resistance, but no such isolate was identified to fine map one of the novel loci in PI 408211B.
Download or read book Identification of Quantitative Trait Loci for Partial Resistance to Phytophthora Sojae in Six Soybean glycine Max L Merr Plant Introductions written by Sungwoo Lee and published by . This book was released on 2013 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In soybean [Glycine max (L.) Merr.], Phytophthora root and stem rot caused by Phytophthora sojae is one of the destructive diseases that result in economic losses around the world. However, changes in P. sojae populations emphasize the integrated use of Rps gene-mediated resistance with partial resistance for more durable and effective defense. Quantitative trait loci (QTL) for partial resistance to P. sojae have been identified in several studies albeit in only a few genetic sources, primarily the cultivar Conrad. The first objective was to characterize six soybean plant introductions originating from East Asia for QTL conditioning partial resistance to P. sojae. The second objective was to evaluate joint-population QTL analysis (via joint inclusive composite interval mapping, JICIM) for the effectiveness of combining multiple populations with heterogeneous experimental conditions. Four populations were F7:8 and two were F4:6 generations, and they were mapped with partially overlapping sets of molecular markers. Resistance was measured either by lesion length in tray tests, or by root colonization, plant weight, root fresh weight, and root dry weight in layer tests. Conventional bi-parental QTL analysis identified ~12 QTL for a measurement in each population via composite interval mapping (CIM) using MapQTL5, which explained ~58% of total phenotypic variance (PV) in each population. Individually, most QTL explained less than 10% of PV. Interestingly, most of the QTL identified in this study mapped closely to other resistance QTL associated with resistance to other pests or pathogens or R-gene clusters. Joint-population QTL analysis (JICIM) detected the same QTL which were identified in each single-population analysis (Inclusive composite interval mapping, ICIM). In one pair of two populations with the fewest confounding factors, joint-population analysis detected an additional QTL; however this was not identified when all six of the populations were combined. In another population which had 128 RILs, no QTL were identified using the ICIM method compared to 1 QTL identified with MapQTL5. When populations were combined that were evaluated with different phenotypic methods, the same QTL were identified in the combined analysis compared to each population analyzed independently. Thus differences in phenotypic analysis did not largely affect the detection of these QTL. This study identified some limits in the use of joint linkage analysis and parameters for combining populations to detect additional QTL. Detection of additional QTL with this analysis will be enhanced if the populations are advanced beyond the F4, markers are fully integrated into large chromosome segments, and populations are sufficiently large. More importantly, populations which were evaluated with different phenotypic methods can be combined, provided common checks were used and data were normalized with the checks’ values. Many of the QTL identified in these six populations through both analyses overlapped at multiple genomic positions, while many were distinct from QTL identified in Conrad. This suggests that the QTL identified in this study will be useful in diversifying the US soybean cultivars and providing new genes to enhance resistance to P. sojae through breeding.
Download or read book Characterization of Rps8 and Rps3 Resistance Genes to Phytophthora Sojae Through Genetic Fine Mapping and Physical Mapping of Soybean Chromosome 13 written by Andika Gunadi and published by . This book was released on 2012 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Dominant race-specific resistance genes in soybean [Glycine max (L.) Merrill] is a major component in the management of the root and stem rot pathogen Phytophthora sojae Kaufmann and Gerdemann. Several of these resistance genes, namely Rps3a, Rps3b, Rps3c and Rps8 were mapped in previous studies within the vicinity of a resistance-gene-rich region on the long arm of soybean chromosome 13. These genes provide valuable resources for breeding elite soybean cultivars with extended lifetime of resistance to P. sojae. However, a more precise determination of the relationship among these genes, as well as their cloning are necessary for expediting breeding efforts involving gene stacking of resistance genes from chromosome 13. In the first part of this study, allelism studies and linkage analysis were performed to elucidate the genetic distance and the positioning of Rps3a, Rps3c and Rps8. Isolates of P. sojae with virulence patterns specific for avirulence to all 3 genes as well as avirulence or virulence corresponding to one gene or another were used to evaluate the disease resistance within F2:3 and F3:4 mapping populations derived from crosses of soybean genotypes with Rps3a and Rps8, as well as Rps3c and Rps8. The second part of this study involved the screening of Bacterial Artificial Chromosome (BAC) libraries and the sequencing of selected BAC clones for the development of physical map of Rps3a and Rps8 genetic region. The allelism studies suggest that Rps3a and Rps8 are linked at a genetic distance of greater than or equal to 11.0 cM, while Rps3c and Rps8 are not linked. Preliminary genetic linkage maps of the long arm of chromosome 13 have been successfully developed from L83-570 (Rps3aRps3a) PI 399073 (RpsNRpsNRps8Rps8) and L92-7857 (Rps3cRps3c) PI 399073 F3:4 populations. In this study, Rps8 was mapped to a previously reported location in chromosome 13, north of the simple sequence repeat marker Satt114, and flanked by markers Sat_103 and Sat_234. Highly significant association was identified between Rps3c and single nucleotide polymorphism marker on chromosome 18 (BARC-032785-09037, P
Download or read book Study of Incomplete Resistance to Phytophthora Sojae in Soybean written by Santiago Xavier Mideros Mora and published by . This book was released on 2006 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Phytophthora root and stem rot caused by Phytophthora sojae, is a serious limitation to soybean production in the United States. Extensive deployment of Rps genes in soybean cultivars has led to adaptations in the P. sojae populations. Partial resistance to P. sojae in soybeans is effective against all races of the pathogen and is a form of incomplete resistance where the plant reduces the rate of colonization of the pathogen. In addition to partial resistance other types of incomplete resistance have also been described. Rps2 is a single dominant gene that confers incomplete resistance in soybean hypocotyls. Root resistance, thought to be quantitatively inherited, is another form of race specific resistance that appears to function only in the roots. In order to differentiate partial resistance from the other types of incomplete resistance that are race specific, components of resistance were analyzed and the cytology of infection compared. For this study attempts to genetically transform P. sojae to express a marker gene were unsuccessful. Three components were measured (lesion length, oospore production and infection frequency) in 8 soybean genotypes that were inoculated with non-transformed P. sojae isolates on the roots. Light and epifluorescent microscopy were used to study transversal cuts of Trypan blue stained root samples that were also inoculated with P. sojae. Soybean partial resistance was found to be composed of various components that interact to produce the partial resistance phenotype for defense against P. sojae in the roots. It was also found that the Rps2 and root resistant genotypes had significantly reduced levels for all of the components of resistance studied in comparison to the partially resistant genotype Conrad. However, the high levels of partial resistance in Jack were indistinguishable from the Rps2 reaction for all the components studied. In the cytology study it was found that P. sojae penetrates into all the soybean incomplete resistant genotypes: partial resistant, Rps2, and root resistant. Several mechanisms of resistance were observed: i) the resistance phenotype (Rpsla) contained the pathogen biotrophic growth from between 0 to 24 hal in a hypersensitive response; ii) Rps2 and root resistance phenotypes, also stopped growth of the pathogen but this occurred between 24 and 48 hal in a delayed hypersensitive response and iii) the partial resistance and the susceptible phenotypes allowed biotrophic colonization ofF. sojae. Finally a methodology to differentiate among mechanisms of incomplete resistance to P. sojae in soybean was identified based on the number of dead cells and extent of colonization that differed in partial resistance and Rps2 phenotypes.
Download or read book Interaction Between Soybean and Phytophthora Sojae written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterization of a Major Quantitative Disease Resistance Locus for Partial Resistance to Phytophthora Sojae written by Stephanie Renae Karhoff and published by . This book was released on 2019 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phytophthora root and stem rot is caused by the soil-borne oomycete Phytophthora sojae. Host resistance is the main management practice for Phytophthora root and stem rot, and breeders have historically relied on single, major resistance (Rps) genes. However, pathogen populations have adapted to the previously deployed Rps genes. An alternative is to breed for higher levels of partial resistance, which is quantitatively inherited and typically non isolate-specific. Partial resistance is controlled by multiple quantitative disease resistance loci (QDRL). A QDRL explaining up to 45% of the phenotypic variation (PV) was previously identified in plant introduction (PI) 427106 and PI 427105B (QDRL-18). Major QDRL are rare in the soybean – P. sojae pathosystem; thus, near isogenic lines (NILs) contrasting at QDRL-18 were developed and used to test for isolate-specificity, pleiotropic effects, and validate the locus across environments and genetics backgrounds. Resistant introgressions from either PI 427105B or PI 427106 were effective against seven P. sojae isolates of varying pathotype complexity and increased resistance to P. sojae by 11-20% and 35-40% in laboratory and greenhouse assays, respectively. Furthermore, within the NIL set 4060, lines carrying resistant introgression R105B significantly out-yielded lines with the susceptible introgression SOX under highly favorable disease conditions. In order to facilitate future gene cloning and marker-assisted-selection, RNA-Sequencing of a subset of NILs was completed in conjunction with high resolution mapping of this locus. High-resolution mapping of QDRL-18 with 224-233 markers reduced the original 1,852 Kb interval to a 731 Kb region. Within the refined QDRL, seven genes were differentially expressed following inoculation with P. sojae. Of these seven, one gene putatively encoding a receptor-like protein kinase was significantly downregulated in NILs carrying the resistant introgression derived from PI 427105B at all tested time points. The narrowed QDRL-18 region will provide more closely linked markers and prioritizes candidate genes for future functional analyses. Finally, an obstacle to better understanding the genetic mechanisms of quantitative disease resistance is the identification of causal genes underlying resistance loci. Expression quantitative trait loci (eQTL) analysis has emerged as a method for candidate gene identification, but it requires that the population and conditions in which transcript abundance levels and phenotypic values are obtained be the same. Thus, phenotypic quantitative trait loci (pQTL) were identified in a separate mapping population, derived from a cross between `Conrad’ and `Sloan’, to leverage a larger eQTL study aimed at identifying resistance mechanisms. Two suggestive and one significant pQTL were identified on chromosomes 10 and 18. Most notably, a cis-eQTL coincided with pQTL located on chromosome 18 and is associated with the expression of a gene putatively encoding a leucine-rich repeat receptor-like protein kinase. Overall, this work contributes to the ongoing effort to (1) better understand the mechanisms associated with partial resistance to P. sojae and (2) develop soybean cultivars with increased levels of partial resistance.
Download or read book Spatial and Temporal Analysis of Chitinase Accumulation and Pathogen Colonization in Soybeans with Tolerance to Phytophthora Sojae Infection written by Kitrina Murie Carlson and published by . This book was released on 2003 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tolerance to Phytophthora root rot (PRR) in soybean is a highly-heritable, multi-genic trait. Tolerance is a desirable trait in soybean lines because it is not race-specific and cannot be overcome by a buildup of a specific Phytophthora sojae races, unlike race-specific, single gene resistance. The plant-pathogen interactions occurring in the tolerant reaction to disease have not been thoroughly characterized. The objective of this research was to characterize components of the plant-pathogen interaction occurring in tolerant soybeans infected with P. sojae that may be involved in limiting pathogen colonization and disease development. One important aspect of this interaction is the timing of localized and systemic defense responses. Using chitinase as a marker of defense response activation, I characterized spatial and temporal patterns of chitinase isoform expression. I found that unique chitinase isoforms accumulate in soybean roots infected with P. sojae . Some of these isoforms are expressed earlier in tolerant cultivars than in susceptible cultivars and some of these isoforms are expressed systemically in tolerant cultivars and only locally in susceptible cultivars. This has helped to elucidate differences in the plant defense response between tolerant and susceptible cultivars. Another important component of this interaction is the events involved in pathogen colonization of the root. To analyze the timing and extent of P. sojae colonization of the soybean root system, I utilized real-time PCR to detect and quantify P. sojae within the soybean root system. My results suggest P. sojae colonizes tolerant cultivars more slowly and to a lesser degree than susceptible cultivars.
Download or read book Biotechnological Approaches in Biocontrol of Plant Pathogens written by K.G. Mukerji and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological control offers a promising alternative to chemical control which can have adverse environmental implications. This volume contains 16 articles describing the most modern topics in biocontrol of plant pathogens, including risk analysis for the release of microbial antagonists, genetic engineering and application of tissue culture.
Download or read book Pest Management in Soybean written by L.G. Copping and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the third in a series of volumes on major tropical and sub-tropical crops. These books aim to review the current state of the art in management of the total spectrum of pests and diseases which affect these crops in each major growing area using a multi-disciplinary approach. Soybean is economically the most important legume in the world. It is nutritious and easily digested, and is one of the richest and cheapest sources of protein. It is currently vital for the sustenance of many people and it will play an integral role in any future attempts to relieve world hunger. Soybean seed contains about 17% of oil and about 63% of meal, half of which is protein. Modern research has developed a variety of uses for soybean oil. It is processed into margarine, shortening, mayonnaise, salad creams and vegetarian cheeses. Industrially it is used in resins, plastics, paints, adhesives, fertilisers, sizing for cloth, linoleum backing, fire extinguishing materials, printing inks and a variety of other products. Soybean meal is a high-protein meat substitute and is used in the developed countries in many processed foods, including baby foods, but mainly as a feed for livestock. Soybean (Glycine max), which evolved from Glycine ussuriensis, a wild legume native to northern China, has been known and used in China since the eleventh century Be. It was introduced into Europe in the eighteenth century and into the United States in 1804 as an ornamental garden plant in Philadelphia.
Download or read book Induced Resistance for Plant Defence written by Dale Walters and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plant diseases worldwide are responsible for billions of dollarsworth of crop losses every year. With less agrochemicals being usedand less new fungicides coming on the market due to environmentalconcerns, more effort is now being put into the use of geneticpotential of plants for pathogen resistance and the development ofinduced or acquired resistance as an environmentally safe means ofdisease control. This comprehensive book examines in depth the development andexploitation of induced resistance. Chapters review currentknowledge of the agents that can elicit induced resistance,genomics, signalling cascades, mechanisms of defence to pests andpathogens and molecular tools. Further chapters consider thetopical application of inducers for disease control, microbialinduction of pathogen resistance, transgenic approaches, pathogenpopulation biology, trade offs associated with induced resistanceand integration of induced resistance in crop protection. The bookconcludes with a consideration of socio-economic driversdetermining the use of induced resistance, and the future ofinduced resistance in crop protection.
Download or read book Electron Microscopy of Plant Pathogens written by Kurt Mendgen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plants, fungi, and viruses were among the first biological objects studied with an electron microscope. One of the two first instruments built by Siemens was used by Helmut Ruska, a brother of Ernst Ruska, the pioneer in constructing electron microscopes. H. Ruska published numerous papers on different biological objects in 1939. In one of these, the pictures by G. A. Kausche, E. Pfankuch, and H. Ruska of tobacco mosaic virus opened a new age in microscopy. The main problem was then as it still is today, to obtain an appropriate preparation of the specimen for observation in the electron microscope. Beam damage and specimen thickness were the first obstacles to be met. L. Marton in Brussels not only built his own instrument, but also made considerable progress in specimen preparation by introducing the impregnation of samples with heavy metals to obtain useful contrast. His pictures of the bird nest orchid root impregnated with osmium were revolutionary when published in 1934. It is not the place here to recall the different techniques which were developed in the subsequent years to attain the modern knowledge on the fine structure of plant cells and of different plant pathogens. The tremendous progress obtained with tobacco mosaic virus is reflected in the chapter by M. Wurtz on the fine structure of viruses in this Volume. New cytochemical and immunological techniques considerably surpass the morphological information obtained from the pathogens, especially at the host-parasite interface.
Download or read book Plant Breeding for Biotic Stress Resistance written by Roberto Fritsche-Neto and published by Springer Science & Business Media. This book was released on 2012-10-01 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experience shows that biotic stresses occur with different levels of intensity in nearly all agricultural areas around the world. The occurrence of insects, weeds and diseases caused by fungi, bacteria or viruses may not be relevant in a specific year but they usually harm yield in most years. Global warming has shifted the paradigm of biotic stresses in most growing areas, especially in the tropical countries, sparking intense discussions in scientific forums. This book was written with the idea of collecting in a single publication the most recent advances and discoveries concerning breeding for biotic stresses, covering all major classes of biotic challenges to agriculture and food production. Accordingly, it presents the state-of-the-art in plant stresses caused by all microorganisms, weeds and insects and how to breed for them. Complementing Plant Breeding for Abiotic Stress Tolerance, this book was written for scientists and students interested in learning how to breed for biotic stress scenarios, allowing them to develop a greater understanding of the basic mechanisms of resistance to biotic stresses and develop resistant cultivars.
Download or read book Fungal Pathology written by J.W. Kronstad and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together twelve chapters on fungal pathogens with the goal of presenting an overview of the current areas of activity and the common themes that pervade research on these important organisms. The timing of the book is appropriate because we have gained sufficient insight from molecular genetic analyses to begin to make some comparisons between different fungal pathogens and to discuss the key advances that have been made. The chapters provide a broad survey of the important topics in fungal pathogenesis including morphogenesis, virulence, avirulence, and signaling. The reader also will fmd clear discussions of parasitism, mutualism, symbiosis, evolution, phylogeny and ecology for those fungi where these issues are especially important. Finally, many of the chapters in this book illustrate the fact that we are on the verge of a revolution in our understanding of fungal pathogens because of the application of genomics to these organisms and their hosts. The fungi included in this book represent many of the most intensively investigated fungal pathogens of plants; in this regard, a chapter is also included for pathogens in the Phytophthora group, even though these organisms are no longer classified as fungi. It is appropriate to include Phytophthora for historical reasons and, in addition, the insights in terms of pathogenesis and host-specific interactions are important to keep in mind when considering fungal pathogens. Chapters are also included on pathogens of insects and humans, as well as endophytic fungi.
Download or read book Microbial mediated Induced Systemic Resistance in Plants written by Devendra K. Choudhary and published by Springer. This book was released on 2016-03-22 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: With a focus on food safety, this book highlights the importance of microbes in sustainable agriculture. Plants, sessile organisms that are considered as primary producers in the ecosystem and communicate with above- and below-ground communities that consist of microbes, insects, and other vertebrate and invertebrate animals, are subjected to various kinds of stress. Broadly speaking, these can be subdivided into abiotic and biotic stresses. Plants have evolved to develop elaborate mechanisms for coping with and adapting to the environmental stresses. Among other stresses, habitat-imposed biotic stress is one serious condition causing major problems for crop productivity. Most plants employ plant-growth-promoting microorganisms (PGPMs) to combat and protect themselves from stresses and also for better growth. PGPMs are bacteria associated with plant roots and they augment plant productivity and immunity. They are also defined as root-colonizing bacteria that have beneficial effects on plant growth and development. Remarkably, PGPMs including mycorrhizae, rhizobia, and rhizobacteria (Acinetobacter, Agrobacterium, Arthrobacter, Azospirillum, Bacillus, Bradyrhizobium, Frankia, Pseudomonas, Rhizobium, Serratia, Thiobacillus) form associations with plant roots and can promote plant growth by increasing plants’ access to soil minerals and protecting them against pathogens. To combat the pathogens causing different diseases and other biotic stresses, PGPMs produce a higher level of resistance in addition to plants’ indigenous immune systems in the form of induced systemic resistance (ISR). The ISR elicited by PGPMs has suppressed plant diseases caused by a range of pathogens in both the greenhouse and field. As such, the role of these microbes can no longer be ignored for sustainable agriculture. Today, PGPMs are also utilized in the form of bio-fertilizers to increase plant productivity. However, the use of PGPMs requires a precise understanding of the interactions between plants and microbes, between microbes and microbiota, and how biotic factors influence these relationships. Consequently, continued research is needed to develop new approaches to boost the efficiency of PGPMs and to understand the ecological, genetic and biochemical relationships in their habitat. The book focuses on recent research concerning interactions between PGPMs and plants under biotic stress. It addresses key concerns such as – 1. The response of benign microbes that benefit plants under biotic stress 2. The physiological changes incurred in plants under harsh conditions 3. The role of microbial determinants in promoting plant growth under biotic stress The book focuses on a range of aspects related to PGPMs such as their mode of action, priming of plant defence and plant growth in disease challenged crops, multifunctional bio-fertilizers, PGPM-mediated disease suppression, and the effect of PGPMs on secondary metabolites etc. The book will be a valuable asset to researchers and professionals working in the area of microbial-mediated support of plants under biotic stress.
