Download or read book Recombinants of Bean Common Mosaic Virus BCMV and Genetic Determinants of BCMV Involved in Overcoming Resistance in Common Beans written by Xue Feng and published by . This book was released on 2014 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bean common mosaic virus (BCMV) exists as a complex of strains, which have been classified into seven pathogroups. These BCMV strains and strains of the closely related Bean common mosaic necrosis virus (BCMNV) can be distinguished based on their biological, molecular and serological properties. Seven resistance genes govern interactions of common beans (Phaseolus vulgaris ) and BCMV/BCMNV strains: one dominant I gene, and six recessive genes, bc-u, bc-1 and an allelic bc-12, bc-2 and an allelic bc-22, and bc-3. Prior to this work, virus genetic determinants involved in pathogenicity interactions of BCMV with resistance genes were not identified or mapped. Here, we conducted a systematic study of biological and molecular properties of a group of field-collected and reference BCMV isolates in order to identify genetic determinants involved in interactions with three recessive genes, bc-1, bc-2, and bc-22, and the dominant I gene. Through comparative genomics of four closely related BCMV isolates from the RU1 strain group, and three other BCMV strains, US1, US10, and NY15P, putative genetic determinants interacting with recessive genes, bc-1, bc-2, and bc-22, as well as the dominant I gene in P. vulgaris were identified and mapped to the P1 and HC-Pro regions. Genome diversity we found in this study suggested BCMV strains represented multiple recombinants, and the occurrence of recombination in BCMV genome may or may not lead to pathogenicity changes. Due to the wide spread of recombination in BCMV strains, partial sequencing cannot be a reliable means of BCMV strain classification..

Download or read book Bean Common Mosaic written by Francisco José Morales and published by CIAT. This book was released on 1989 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Determining the Mechanism of the Recessive Resistance to Bean Common Mosaic Virus BCMV Conferred by the Bc 1 and Bc 2 Recessive Genes in Common Bean and Biological and Molecular Characterization of a New Strain of BCMV written by Gardenia Edith Orellana Arreaga and published by . This book was released on 2019 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bean common mosaic virus (BCMV) is an important pathogen affecting common bean and other legumes. BCMV is an aphid-transmitted virus, which can also be seed-transmissible in common bean with efficiencies of up to 80%, depending on virus strain and bean cultivar. The virus belongs to the genus Potyvirus (family Potyviridae), having an approximately 10-kb single-stranded, positive-sense RNA genome. BCMV resistance in common bean is governed by one dominant (I) gene and four recessive (bc-u, bc-1, bc-2, and bc-3) genes which are deployed by breeders in different combinations to protect commercial bean cultivars against the virus. The dominant I gene confers extreme resistance or immunity against all strains of BCMV when the temperature stays below 30°C, and variable types of local and systemic necrosis when temperature exceeds 30°C. The bc-3 gene was identified as an eIF4E translation initiation factor gene mediating resistance through disruption of the interaction between this protein and the VPg protein of the virus. The mode of action of bc-1 and bc-2 in expression of BCMV resistance was unknown until this work. To investigate the possible role of both bc-1 and bc-2 genes in replication, cell-to-cell, and long distance movement of BCMV in P. vulgaris, we tested virus spread of eight BCMV isolates representing pathogroups I, IV, VI, VII, and VIII, in a set of bean differentials expressing different combinations of six resistance alleles including bc-u, bc-1, bc-12, bc-2, bc-22, and bc-3. The data suggest that bc-1 and bc-2 recessive resistance genes have no effect on the replication and cell-to-cell movement of BCMV, but affect systemic spread of BCMV in common bean. The BCMV resistance conferred by bc-1 and bc-2 and affecting systemic spread was found only partially effective when these two genes were expressed singly. The efficiency of the restriction of the systemic spread of the virus was greatly enhanced when the alleles of bc-1 and bc-2 genes were combined together.Beside common bean, there are other crop legumes that are susceptible to BCMV, such as peanut, soybean, and azuki bean. In this thesis, I described a new strain of BCMV from lima bean with distinct biological and molecular characteristics found in Honolulu, HI. This new BCMV strain, BCMV-A1, was able to partially overcome resistance to the virus conferred by bc-1 and bc-2 alleles in common bean, establishing an asymptomatic systemic infection in some common bean cultivars. Later, two BCMV isolates were found in commercial common bean samples in Idaho exhibiting 99% identity to BCMV-A1 in partial genome sequence. This new BCMV strain from lima bean, BCMV-A1, may present a threat for the common bean production.

Download or read book Gene Ecology of the Climbing Common Bean Phaseolus Vulgaris Bean Common Mosaic Virus Bean Common Mosaic Necrosis Virus BCMV BCMVN Relationship in Rwanda written by Alice Kabeja and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Common beans (Phaseolus vulgaris) are nutritionally, culturally, and economically an important legume crop in Rwanda. Beans provide 32 and 65 percent of calories and protein intake in the Rwandan diet, whereas protein sourced from animal provides only 4 percent of the protein intake. Unfortunately, common bean production is constrained by multiple biotic and abiotic factors in this country. Among others, Bean common mosaic virus and Bean common mosaic necrosis virus (BCMV/BCMNV) are seedborne viral pathogens that are the main constraint in common bean production. The only effective control of these pathogens is through the use of genetic resistance. Currently, the status of BCMV/BCMNV in Rwanda is not known. To contribute to the research in breeding common bean against BCMV/BCMNV in Rwanda, I sought to better understand the variability and biology of the BCMV/BCMNV pathogen to assist in developing a resistance strategy in common bean that is broader and stronger. In the first chapter, I was interested in determining the types of BCMV/BCMNV strains that are present in Rwanda. I was also interested in identifying the selective pressures these viruses are subjected to and how they govern the evolution of these viruses in Rwanda. Furthermore, I wanted to find out if there are alternate hosts other than common bean for BCMV/BCMNV in Rwanda. To gain this information, I surveyed common bean fields extensively in high-altitude areas of Rwanda. The biological and molecular pathogenic characterization studies of isolates of BCMV and BCMNV resulting from these surveys revealed the exclusive presence of BCMNV in Rwanda. No BCMV strain were found. We observed the predominance of the NL-3 strain of BCMNV. The study of genetic diversity for coat protein (CP) fragment of the BCMNV isolates showed a low genetic diversity ([pi] = 0.015623). The mean [omega] (dN/dS) value for CP of 27 isolates analyzed here was less than 1.0, indicating that the CP segment of BCMNV in Rwanda is subject to negative or purifying selection. No alternative hosts to Phaseolus vulgaris for either BCMV or BCMNV were identified in this study. For now, the resistance of BCMV/BCMNV in host plant is controlled by seven resistance genes: one dominant gene (I gene), five recessive strain-specific genes (bc-1, bc-12, bc-2, bc-22, and bc-3), and one strain-nonspecific epistatic gene (bc-u). However, few studies have been carried out on bc-12 (Miklas et al.; 2000). In the second chapter, through the development and evaluation of Recombinant Inbreed Lines (RIL) under greenhouse conditions, we investigated if any minor, quantitative loci could be identified for resistance to BCMNV, which would have originated in either of the parents, RWV3006 (bc-12) or Mshindi (bc-12), and would complement the major resistance gene bc-12. A quantitative trait loci (QTL) study done on these RILs confirmed the presence of bc-12 gene (SS715647636 QTL) on chromosome PV03 as expected. However, another QTL (SS715645701) with a smaller effect was found on Pv09. Interestingly, the positive (resistant) allele at this QTL came from RWV 3006, the susceptible parent. Results from this study showed that the combination of both QTLs increases resistance, either at the heterozygous or homozygous state. It sets the stage for further surveys of minor viral resistance genes in common-bean germplasm. To facilitate future breeding efforts, in the third chapter I attempted to obtain tightly-linked markers useful for marker-assisted selection (MAS) of the bc-12 gene in the presence of other epistatic virus resistance genes. These markers should be more broadly applicable to different genetic backgrounds, reproducible across laboratories, and able to distinguish homozygotes from heterozygotes (co-dominant). Based on a known SNP marker linked to bc-12 resistance gene, we developed a dCAPS (derived Cleaved Amplified Polymorphic Sequence) marker. However, it was not possible to clearly visualize the polymorphism generated by the designed dCAPSHindIII marker on agarose gels in all tested genotypes. This may be explained by the small size of the marker. The low resolution of the agarose gel could not detect small size differences as effectively as polyacrylamide gel electrophoresis, which can distinguish fragments with few (one to five) base pairs difference. We suggest that the marker should be tested in a larger number of different bean seed types to ascertain its usefulness in different bean classes. Furthermore, in future work with this dCAPSHindIII marker, the use of polyacrylamide gel could facilitate effective discrimination between DNA fragments from the resistant and susceptible parents.

Download or read book Mechanism of Resistance to Bean Common Mosaic Virus Conferred by the I Locus in Phaseolus Vulgaris L written by Molly Melinda Cadle-Davidson and published by . This book was released on 2005 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genomic Designing for Biotic Stress Resistant Pulse Crops written by Chittaranjan Kole and published by Springer Nature. This book was released on 2022-03-18 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biotic stresses cause yield loss of 31-42% in crops in addition to 6-20% during post-harvest stage. Understanding interaction of crop plants to the biotic stresses caused by insects, bacteria, fungi, viruses, and oomycetes, etc. is important to develop resistant crop varieties. Knowledge on the advanced genetic and genomic crop improvement strategies including molecular breeding, transgenics, genomic-assisted breeding and the recently emerging genome editing for developing resistant varieties in pulse crops is imperative for addressing FPNEE (food, health, nutrition. energy and environment) security. Whole genome sequencing of these crops followed by genotyping-by-sequencing have facilitated precise information about the genes conferring resistance useful for gene discovery, allele mining and shuttle breeding which in turn opened up the scope for 'designing' crop genomes with resistance to biotic stresses. The nine chapters each dedicated to a pulse crop in this volume elucidate on different types of biotic stress agents and their effects on and interaction with the crop plants; enumerate on the available genetic diversity with regard to biotic stress resistance among available cultivars; illuminate on the potential gene pools for utilization in interspecific gene transfer; present brief on the classical genetics of stress resistance and traditional breeding for transferring them to their cultivated counterparts; depict the success stories of genetic engineering for developing biotic stress resistant varieties; discuss on molecular mapping of genes and QTLs underlying biotic stress resistance and their marker-assisted introgression into elite varieties; enunciate on different emerging genomics-aided techniques including genomic selection, allele mining, gene discovery and gene pyramiding for developing resistant crop varieties with higher quantity and quality of yields; and also elaborate some case studies on genome editing focusing on specific genes for generating disease and insect resistant crops.

Download or read book Genetic Relationship Between the Reaction of Dry Bean Genotypes Phaseolus Vulgaris L to Bean Common Mosaic Virus and Bean Yellow Mosaic Virus written by Martin Nyololani Mbewe and published by . This book was released on 1989 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Factors Affecting the Production of Local Lesions by Bean Common Mosaic Virus BCMV written by Gustavo Enrique Trujillo and published by . This book was released on 1971 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Identification of Necrosis inducing Strains of Bean Common Mosaic Virus and Breeding for Resistance written by Milton A. Morales Lopez and published by . This book was released on 1983 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The I Gene and Broad Spectrum Plant Virus Resistance in Phaseolus Vulgaris L written by Margaret Miller Kyle and published by . This book was released on 1988 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Characterization and Detection of Two Common Bean Phaseolus Vulgaris L Pathogens written by Pablo Guzman and published by . This book was released on 1997 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiplication and Distribution of Bean Common Mosaic Virus BCMV in Bean written by Ephraim J. A. Ekpo and published by . This book was released on 1972 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bean Common Mosaic Virus and Related Viruses in Africa written by Nicola J. Spence and published by . This book was released on 1994 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of current research, including the results of an identification survey throughout the main bean-growing areas. Findings on the interaction between transmission rates and new viral strains with host range and resistance lead to a discussion on the implications for control practices.

Download or read book Phyllosphere Microbial Plant Pathogens Detection and Crop Disease Management written by P. Narayanasamy and published by CRC Press. This book was released on 2024-08-15 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides comprehensive knowledge of the methods of detection and identification of phyllosphere microbial pathogens and the management of different kinds of diseases caused by them in various crops. Interactions between pathogens and host plants result in the induction of defense responses expressed via molecular signals, from initiation of infection to systemic progression of pathogen invasion in susceptible plants and contrasting signals in resistant plants, leading to inhibition of pathogen development through activation of preinfectional and postinfectional defense responses. These are critically discussed. The author describes the intricate and complex competitive activities of the pathogens and host plants in a molecular warfare that the host plant must win to break the link in the pathogens' life cycle, allowing the development of disease management strategies based on the principles of exclusion, eradication, and immunization. Integration of strategies concerning the development of cultivars resistant to pathogens through breeding and biotechnological techniques, application of biotic and abiotic inducers of resistance to pathogens, and use of disease-free seeds and propagules that are complementary to each other along with effective cultural practices are emphasized. This book presents information gathered through an extensive literature search to help researchers and graduate students in agricultural sciences identify research gaps and successfully complete their research projects.

Download or read book Breeding for Resistance to Bean Common Mosaic Necrosis Virus and Molecular Tagging of Bc 3 Gene in Common Bean written by Mukeshimana. Gérardine and published by . This book was released on 2003 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Genetics of Resistance to the Common Bean Mosaic Virus bean Virus 1 in the Bean Phaseolus Vulgaris L written by Mohamed Abd Elkader Ali and published by . This book was released on 1949 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterisation of Pathotypes of Bean Common Mosaic Virus BCMV written by Georgina Marie Donovan and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: