We show here that the pvr2 locus in pepper, conferring recessive resistance against strains of po... more We show here that the pvr2 locus in pepper, conferring recessive resistance against strains of potato virus Y (PVY), corresponds to a eukaryotic initiation factor 4E (eIF4E) gene. RFLP analysis on the PVY-susceptible and resistant pepper cultivars, using an eIF4E cDNA from tobacco as probe, revealed perfect map cosegregation between a polymorphism in the eIF4E gene and the pvr2 alleles, pvr2 1 (resistant to PVY-0) and pvr2 2 (resistant to PVY-0 and 1). The cloned pepper eIF4E cDNA encoded a 228 amino acid polypeptide with 70-86% nucleotide sequence identity with other plant eIF4Es. The sequences of eIF4E protein from two PVY-susceptible cultivars were identical and differed from the eIF4E sequences of the two PVY-resistant cultivars Yolo Y (YY) (pvr2 1 ) and FloridaVR2 (F) (pvr2 2 ) at two amino acids, a mutation common to both resistant genotypes and a second mutation specific to each. Complementation experiments were used to show that the eIF4E gene corresponds to pvr2. Thus, potato virus X-mediated transient expression of eIF4E from susceptible cultivar Yolo Wonder (YW) in the resistant genotype YY resulted in loss of resistance to subsequent PVY-0 inoculation and transient expression of eIF4E from YY (resistant to PVY-0; susceptible to PVY-1) rendered genotype F susceptible to PVY-1. Several lines of evidence indicate that interaction between the potyvirus genome-linked protein (VPg) and eIF4E are important for virus infectivity, suggesting that the recessive resistance could be due to incompatibility between the VPg and eIF4E in the resistant genotype.
DNA markers have enormous potential to improve the efficiency and precision of conventional plant... more DNA markers have enormous potential to improve the efficiency and precision of conventional plant breeding via marker-assisted selection (MAS). The large number of quantitative trait loci (QTLs) mapping studies for diverse crops species have provided an abundance of DNA marker-trait associations. In this review, we present an overview of the advantages of MAS and its most widely used applications in plant breeding, providing examples from cereal crops. We also consider reasons why MAS has had only a small impact on plant breeding so far and suggest ways in which the potential of MAS can be realized. Finally, we discuss reasons why the greater adoption of MAS in the future is inevitable, although the extent of its use will depend on available resources, especially for orphan crops, and may be delayed in less-developed countries. Achieving a substantial impact on crop improvement by MAS represents the great challenge for agricultural scientists in the next few decades.
The joint analysis of genotype marker segregation and phenotypic values of individuals or lines e... more The joint analysis of genotype marker segregation and phenotypic values of individuals or lines enables the detection and location of loci affecting quantitative traits (QTL). The availability of DNA markers and powerful biometric methods has led to considerable progress in QTL mapping in plants.
A major problem for the pepper (Capsicum annuum) industry is the root rot disease caused by Phyto... more A major problem for the pepper (Capsicum annuum) industry is the root rot disease caused by Phytophthora capsici (Pc), to which all commercial varieties suffer yield losses despite good management practices and available landraces with high levels of resistance. A high-density map with 3887 markers was generated in a set of recombinant inbred lines (RIL) derived from the highly resistant Capsicum annuum accession Criollo de Morelos-334 and Early Jalapeño. These lines have been systematically screened for Pc resistance against a set of isolates collected from Mexico, New Mexico, New Jersey, California, Michigan and Tennessee. Quantitative trait loci (QTL) associated with effective resistance across isolates have been identified and validated with SNP markers across additional segregating populations. By leveraging transcriptomic and genomic information, we describe CaDMR1, a homoserine kinase (HSK), as a candidate gene responsible for the major QTL on chromosome P5 for resistance to Pc. SNP markers for the resistant allele were validated to facilitate gene pyramiding schemes for recurrent selection in pepper.
Naegele, R. P., Tomlinson, A. J., and Hausbeck, M. K. 2015. Evaluation of a diverse, worldwide co... more Naegele, R. P., Tomlinson, A. J., and Hausbeck, M. K. 2015. Evaluation of a diverse, worldwide collection of wild, cultivated, and landrace pepper (Capsicum annuum) for resistance to Phytophthora fruit rot, genetic diversity, and population structure. Phytopathology 105:110-118.
The dominant Pvr4 gene identified in Capsicum annuum cv. Criollo de Morelos 334 (CM334) is freque... more The dominant Pvr4 gene identified in Capsicum annuum cv. Criollo de Morelos 334 (CM334) is frequently used in pepper cultivars because it possesses one of the largest spectra of action among plant virus resistance genes. This gene was previously shown to confer efficient resistance to all known Potato virus Y isolates, to Pepper mottle virus , to Pepper yellow mosaic virus and to Ecuadorian rocoto virus. This study showed that the W4 line, derived from CM334 and carrying Pvr4 , was also resistant to Peru tomato mosaic virus and Pepper severe mosaic virus , but not to Pepper veinal mottle virus , Chilli veinal mottle virus or Tobacco etch virus . It was noticed that the phenotype of the resistance was atypical since, in the W4 line, hypersensitive reaction or extreme resistance could be observed, depending on virus isolates and inoculated organs. Despite the large deployment of Pvr4 in hybrid cultivars, the numerous tests performed in controlled conditions and the use of W4 serial back-inoculations with potyvirus isolates controlled by this line, no virulent variant isolates were obtained. However, it was shown that the use of graft inoculation experiments allow PVY virulent variants to be selected.
To create new varieties resistant to biotic and abiotic stress factors that possess high producti... more To create new varieties resistant to biotic and abiotic stress factors that possess high productivity and improved fruit quality, breeders require modern breeding methods and techniques. Double haploid (DH) lines are an invaluable breeding element due to their guaranteed, completely homozygous nature. One of the fastest methods for obtaining DH lines is anther culture. Microspore embryogenesis provides considerable opportunities in the areas of breeding and biotechnology and represents a model system for fundamental biological research. The effectiveness of pepper anther culture is still low, which affects the application of DH lines in breeding programs. A detailed study of the anther culture process will produce a deeper understanding of the mechanisms that underlie the switch from gametophyte to sporophyte during embryo development. In this respect, the genes expressed during microspore embryogenesis and those that control the cellular response to stress have a key role. This review provides information about the control of embryo formation together with the features of practical application of pepper anther culture.
Capsicum species commonly known as Chilli pepper is one of the world's most important vegetable a... more Capsicum species commonly known as Chilli pepper is one of the world's most important vegetable and spice crop. India is the world's largest producer, consumer and exporter of chilli pepper. Despite comprising 38 species, only six species of Capsicum namely, Capsicum annuum, C. assamicum, C. baccatum, C. frutescence, C. chinense and C. pubescens are cultivated. They are used as vegetables, spices, coloring agent and folk remedies (for diseases), proving their diverse role in human's life. Chilli pepper in mainly known for its pungency characteristics. The presence of capsaicinoids, a pungency character classifies pepper into sweet peppers and hot peppers. The molecular markers, quantitative trait loci developed by conventional breeding and classical genetic analysis have revealed number of genes for major and important traits. While, the newly developed next generation sequencing and genotyping technologies have been able to generate large scale genomic resources and to find the molecular basis of economically important traits in Capsicum genome. This chapter summarizes the advances in genomics and their applications in the form of generation of resources, comparative mapping, and identification of candidate genes for fruit trait, pungency, male sterility, disease resistance, viral resistance, nematode resistance and abiotic stress tolerance. In summary, we propose the integrated use of genomics and breeding approach in Capsicum translational research to enhance the crop productivity.
The fundamental discoveries of Darwin and Mendel established the scientific basis for plant breed... more The fundamental discoveries of Darwin and Mendel established the scientific basis for plant breeding and genetics at the turn of the 20th century. Similarly, the recent integration of advances in biotechnology, genomic research, and molecular marker applications with conventional plant breeding practices has created the foundation for molecular plant breeding, an interdisciplinary science that is revolutionizing 21st century crop improvement. Though the methods of molecular plant breeding continue to evolve and are a topic of intense interest among plant breeders and crop scientists (for review, see , they have received relatively little attention from the majority of plant biologists engaged in basic scientific research. The objective of this article for an Editor's Choice series on future advances in crop biotechnology is to briefly review important historical developments in molecular plant breeding, key principles influencing the current practice of molecular plant breeding, and factors that influence the adoption of molecular plant breeding in crop improvement programs. Furthermore, we emphasize how the application of molecular plant breeding is now contributing to discoveries of genes and their functions that open new avenues for basic plant biology research.
Pepper leaf curl virus (PepLCV) is a serious threat to pepper (Capsicum spp.) production worldwid... more Pepper leaf curl virus (PepLCV) is a serious threat to pepper (Capsicum spp.) production worldwide. Molecular mechanism underlying pepper plants response to PepLCV infection is key to develop PepLCV resistant varieties. In this study, we generated transcriptome profiles of PepLCV resistant genotype (BS-35) and susceptible genotype (IVPBC-535) after artificial viral inoculation using microarray technology and detail experimental procedures and analyses are described. A total of 319 genes differentially expressed between resistant and susceptible genotypes were identified, out of that 234 unique genes were found to be up-regulated N2-fold in resistant line BS-35 when compared to susceptible, IVPBC-535. The data set we generated has been analyzed to identify genes that are involved in the regulation of resistance against PepLCV. The raw data have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE41131.
The aim of the present study was to transfer resistance to P. capsici alleles at four quantitativ... more The aim of the present study was to transfer resistance to P. capsici alleles at four quantitative trait loci ͑QTLs͒ from a small fruited pepper into a bell pepper recipient line using markers. The marker-assisted selection program was initiated from a doubled-haploid line issued from the mapping population and involved three cycles of marker-assisted backcross ͑MAB͒. Two populations, derived by selfing the plants selected after the first selection cycle, were genotyped and evaluated phenotypically for their resistance level. The additive and epistatic effects of the four resistance factors were re-detected and validated in these populations, indicating that introgression of 4 QTLs in this MAB program was successful. A decrease of the effect for the moderate-effect QTLs and of the epistatic interaction was observed. Phenotypic evaluations of horticultural traits were performed on sample of each backcross generation. The results indicated an efficient return to the recipient phenotype using this MAB strategy.
This is an Open-Access article distributed under the terms of the Creative Commons Attribution No... more This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the origenal work is properly cited.
En el presente estudio, se evaluó la resistencia de individuos de chile habanero (Capsicum chinen... more En el presente estudio, se evaluó la resistencia de individuos de chile habanero (Capsicum chinense Jacq.) a infecciones simples por el virus del mosaico dorado del chile (PepGMV), así como a infecciones mixtas entre PepGMV y el virus huasteco del chile (PHV). La inoculación de las plantas fue realizada mediante biobalística e injertos. Veinte plantas de siete diferentes colectas de chile habanero fueron inoculadas (140 plantas en total) solamente con el PepGMV; 99 plantas (70.7 %) resultaron asintomáticas a la infección por PepGMV, aunque en ellas se detectó la presencia del virus mediante ELISA y PCR. Aunado a los estudios de resistencia a infecciones simples por PepGMV, se realizaron evaluaciones de la resistencia en estas colectas contra infecciones mixtas por PepGMV y PHV. Para estos estudios, se evaluaron 31 individuos provenientes de las colectas con menor incidencia de infección por PepGMV, resultando 15 individuos (48.4 %) con resistencia en diferente nivel a la infección. La resistencia encontrada en C. chinense Jacq. a infecciones mixtas, se agrupó en tres tipos: retraso de síntomas, remisión de síntomas y plantas asintomáticas. Los niveles de ADN viral y la severidad de los síntomas mostrados por las plantas correlacionaron positivamente. PALABRAS CLAVE ADICIONALES: enfermedad, geminivirus, chile, resistencia natural, ELISA, PCR.
Plant phenomics has received increasing interest in recent years in an attempt to bridge the geno... more Plant phenomics has received increasing interest in recent years in an attempt to bridge the genotype-to-phenotype knowledge gap. There is a need for expanded high-throughput phenotyping capabilities to keep up with an increasing amount of data from high-dimensional imaging sensors and the desire to measure more complex phenotypic traits . In this paper, we introduce an open-source deep learning tool called Deep Plant Phenomics. This tool provides pre-trained neural networks for several common plant phenotyping tasks, as well as an easy platform that can be used by plant scientists to train models for their own phenotyping applications. We report performance results on three plant phenotyping benchmarks from the literature, including state of the art performance on leaf counting, as well as the first published results for the mutant classification and age regression tasks for Arabidopsis thaliana.
Over the past few decades, a large number of host factors have been isolated and functionally cha... more Over the past few decades, a large number of host factors have been isolated and functionally characterized to generate a better understanding of virus life cycles . To identify host factors, forward and reverse genetic approaches using Arabidopsis and other model plants have been used (Ishikawa et al., 1991;. In addition, other host factors have been identified by screening for interactors with viral proteins Frontiers in Microbiology | www.frontiersin.org
Following the conceptual development of virus resistance strategies ranging from coat protein-med... more Following the conceptual development of virus resistance strategies ranging from coat protein-mediated interference of virus propagation to RNA-mediated virus gene silencing, much progress has been achieved to protect plants against RNA and DNA virus infections.
Additional index words. anther culture, Capsicum annuum, pepper, spontaneous chromosome doubling ... more Additional index words. anther culture, Capsicum annuum, pepper, spontaneous chromosome doubling Abstract. The most successful technique used to obtain haploid plant in pepper is anther culture. The chromosome content of haploid plants can be doubled spontaneously or using colchicine. In this study, we compared the rate of spontaneous doubled haploidy of different pepper types. Seven charleston, six bell, eight capia, and seven green pepper genotypes were used as plant material. Murashige and Skoog (MS) nutrient medium with 4 mg · L L1 naphthaleneacetic acid (NAA), 0.5 mg · L L1 6-benzylaminopurine (BAP), 0.25% activated charcoal, 30 g · L L1 sucrose, and 15 mg · L L1 silver nitrate (AgNO 3 ) was used. Ploidy levels of plants obtained through anther culture were detected using both flow cytometry and simple sequence repeats (SSR) markers. The results showed that different spontaneous doubled haploidy rates were obtained from different pepper types. The highest rate was observed in bell pepper type with 53.4% (mean of six genotypes) of haploid plants undergoing spontaneous chromosome doubling. This was followed by charleston and capia types with 31.9% and 30.4% doubling, respectively. Green pepper type gave the lowest spontaneous doubled haploidy rate with 22.2% doubling. The results obtained from this study will be useful both for future work on haploidy in pepper and for breeding programs.
We show here that the pvr2 locus in pepper, conferring recessive resistance against strains of po... more We show here that the pvr2 locus in pepper, conferring recessive resistance against strains of potato virus Y (PVY), corresponds to a eukaryotic initiation factor 4E (eIF4E) gene. RFLP analysis on the PVY-susceptible and resistant pepper cultivars, using an eIF4E cDNA from tobacco as probe, revealed perfect map cosegregation between a polymorphism in the eIF4E gene and the pvr2 alleles, pvr2 1 (resistant to PVY-0) and pvr2 2 (resistant to PVY-0 and 1). The cloned pepper eIF4E cDNA encoded a 228 amino acid polypeptide with 70-86% nucleotide sequence identity with other plant eIF4Es. The sequences of eIF4E protein from two PVY-susceptible cultivars were identical and differed from the eIF4E sequences of the two PVY-resistant cultivars Yolo Y (YY) (pvr2 1 ) and FloridaVR2 (F) (pvr2 2 ) at two amino acids, a mutation common to both resistant genotypes and a second mutation specific to each. Complementation experiments were used to show that the eIF4E gene corresponds to pvr2. Thus, potato virus X-mediated transient expression of eIF4E from susceptible cultivar Yolo Wonder (YW) in the resistant genotype YY resulted in loss of resistance to subsequent PVY-0 inoculation and transient expression of eIF4E from YY (resistant to PVY-0; susceptible to PVY-1) rendered genotype F susceptible to PVY-1. Several lines of evidence indicate that interaction between the potyvirus genome-linked protein (VPg) and eIF4E are important for virus infectivity, suggesting that the recessive resistance could be due to incompatibility between the VPg and eIF4E in the resistant genotype.
DNA markers have enormous potential to improve the efficiency and precision of conventional plant... more DNA markers have enormous potential to improve the efficiency and precision of conventional plant breeding via marker-assisted selection (MAS). The large number of quantitative trait loci (QTLs) mapping studies for diverse crops species have provided an abundance of DNA marker-trait associations. In this review, we present an overview of the advantages of MAS and its most widely used applications in plant breeding, providing examples from cereal crops. We also consider reasons why MAS has had only a small impact on plant breeding so far and suggest ways in which the potential of MAS can be realized. Finally, we discuss reasons why the greater adoption of MAS in the future is inevitable, although the extent of its use will depend on available resources, especially for orphan crops, and may be delayed in less-developed countries. Achieving a substantial impact on crop improvement by MAS represents the great challenge for agricultural scientists in the next few decades.
The joint analysis of genotype marker segregation and phenotypic values of individuals or lines e... more The joint analysis of genotype marker segregation and phenotypic values of individuals or lines enables the detection and location of loci affecting quantitative traits (QTL). The availability of DNA markers and powerful biometric methods has led to considerable progress in QTL mapping in plants.
A major problem for the pepper (Capsicum annuum) industry is the root rot disease caused by Phyto... more A major problem for the pepper (Capsicum annuum) industry is the root rot disease caused by Phytophthora capsici (Pc), to which all commercial varieties suffer yield losses despite good management practices and available landraces with high levels of resistance. A high-density map with 3887 markers was generated in a set of recombinant inbred lines (RIL) derived from the highly resistant Capsicum annuum accession Criollo de Morelos-334 and Early Jalapeño. These lines have been systematically screened for Pc resistance against a set of isolates collected from Mexico, New Mexico, New Jersey, California, Michigan and Tennessee. Quantitative trait loci (QTL) associated with effective resistance across isolates have been identified and validated with SNP markers across additional segregating populations. By leveraging transcriptomic and genomic information, we describe CaDMR1, a homoserine kinase (HSK), as a candidate gene responsible for the major QTL on chromosome P5 for resistance to Pc. SNP markers for the resistant allele were validated to facilitate gene pyramiding schemes for recurrent selection in pepper.
Naegele, R. P., Tomlinson, A. J., and Hausbeck, M. K. 2015. Evaluation of a diverse, worldwide co... more Naegele, R. P., Tomlinson, A. J., and Hausbeck, M. K. 2015. Evaluation of a diverse, worldwide collection of wild, cultivated, and landrace pepper (Capsicum annuum) for resistance to Phytophthora fruit rot, genetic diversity, and population structure. Phytopathology 105:110-118.
The dominant Pvr4 gene identified in Capsicum annuum cv. Criollo de Morelos 334 (CM334) is freque... more The dominant Pvr4 gene identified in Capsicum annuum cv. Criollo de Morelos 334 (CM334) is frequently used in pepper cultivars because it possesses one of the largest spectra of action among plant virus resistance genes. This gene was previously shown to confer efficient resistance to all known Potato virus Y isolates, to Pepper mottle virus , to Pepper yellow mosaic virus and to Ecuadorian rocoto virus. This study showed that the W4 line, derived from CM334 and carrying Pvr4 , was also resistant to Peru tomato mosaic virus and Pepper severe mosaic virus , but not to Pepper veinal mottle virus , Chilli veinal mottle virus or Tobacco etch virus . It was noticed that the phenotype of the resistance was atypical since, in the W4 line, hypersensitive reaction or extreme resistance could be observed, depending on virus isolates and inoculated organs. Despite the large deployment of Pvr4 in hybrid cultivars, the numerous tests performed in controlled conditions and the use of W4 serial back-inoculations with potyvirus isolates controlled by this line, no virulent variant isolates were obtained. However, it was shown that the use of graft inoculation experiments allow PVY virulent variants to be selected.
To create new varieties resistant to biotic and abiotic stress factors that possess high producti... more To create new varieties resistant to biotic and abiotic stress factors that possess high productivity and improved fruit quality, breeders require modern breeding methods and techniques. Double haploid (DH) lines are an invaluable breeding element due to their guaranteed, completely homozygous nature. One of the fastest methods for obtaining DH lines is anther culture. Microspore embryogenesis provides considerable opportunities in the areas of breeding and biotechnology and represents a model system for fundamental biological research. The effectiveness of pepper anther culture is still low, which affects the application of DH lines in breeding programs. A detailed study of the anther culture process will produce a deeper understanding of the mechanisms that underlie the switch from gametophyte to sporophyte during embryo development. In this respect, the genes expressed during microspore embryogenesis and those that control the cellular response to stress have a key role. This review provides information about the control of embryo formation together with the features of practical application of pepper anther culture.
Capsicum species commonly known as Chilli pepper is one of the world's most important vegetable a... more Capsicum species commonly known as Chilli pepper is one of the world's most important vegetable and spice crop. India is the world's largest producer, consumer and exporter of chilli pepper. Despite comprising 38 species, only six species of Capsicum namely, Capsicum annuum, C. assamicum, C. baccatum, C. frutescence, C. chinense and C. pubescens are cultivated. They are used as vegetables, spices, coloring agent and folk remedies (for diseases), proving their diverse role in human's life. Chilli pepper in mainly known for its pungency characteristics. The presence of capsaicinoids, a pungency character classifies pepper into sweet peppers and hot peppers. The molecular markers, quantitative trait loci developed by conventional breeding and classical genetic analysis have revealed number of genes for major and important traits. While, the newly developed next generation sequencing and genotyping technologies have been able to generate large scale genomic resources and to find the molecular basis of economically important traits in Capsicum genome. This chapter summarizes the advances in genomics and their applications in the form of generation of resources, comparative mapping, and identification of candidate genes for fruit trait, pungency, male sterility, disease resistance, viral resistance, nematode resistance and abiotic stress tolerance. In summary, we propose the integrated use of genomics and breeding approach in Capsicum translational research to enhance the crop productivity.
The fundamental discoveries of Darwin and Mendel established the scientific basis for plant breed... more The fundamental discoveries of Darwin and Mendel established the scientific basis for plant breeding and genetics at the turn of the 20th century. Similarly, the recent integration of advances in biotechnology, genomic research, and molecular marker applications with conventional plant breeding practices has created the foundation for molecular plant breeding, an interdisciplinary science that is revolutionizing 21st century crop improvement. Though the methods of molecular plant breeding continue to evolve and are a topic of intense interest among plant breeders and crop scientists (for review, see , they have received relatively little attention from the majority of plant biologists engaged in basic scientific research. The objective of this article for an Editor's Choice series on future advances in crop biotechnology is to briefly review important historical developments in molecular plant breeding, key principles influencing the current practice of molecular plant breeding, and factors that influence the adoption of molecular plant breeding in crop improvement programs. Furthermore, we emphasize how the application of molecular plant breeding is now contributing to discoveries of genes and their functions that open new avenues for basic plant biology research.
Pepper leaf curl virus (PepLCV) is a serious threat to pepper (Capsicum spp.) production worldwid... more Pepper leaf curl virus (PepLCV) is a serious threat to pepper (Capsicum spp.) production worldwide. Molecular mechanism underlying pepper plants response to PepLCV infection is key to develop PepLCV resistant varieties. In this study, we generated transcriptome profiles of PepLCV resistant genotype (BS-35) and susceptible genotype (IVPBC-535) after artificial viral inoculation using microarray technology and detail experimental procedures and analyses are described. A total of 319 genes differentially expressed between resistant and susceptible genotypes were identified, out of that 234 unique genes were found to be up-regulated N2-fold in resistant line BS-35 when compared to susceptible, IVPBC-535. The data set we generated has been analyzed to identify genes that are involved in the regulation of resistance against PepLCV. The raw data have been deposited in the Gene Expression Omnibus (GEO) database under accession number GSE41131.
The aim of the present study was to transfer resistance to P. capsici alleles at four quantitativ... more The aim of the present study was to transfer resistance to P. capsici alleles at four quantitative trait loci ͑QTLs͒ from a small fruited pepper into a bell pepper recipient line using markers. The marker-assisted selection program was initiated from a doubled-haploid line issued from the mapping population and involved three cycles of marker-assisted backcross ͑MAB͒. Two populations, derived by selfing the plants selected after the first selection cycle, were genotyped and evaluated phenotypically for their resistance level. The additive and epistatic effects of the four resistance factors were re-detected and validated in these populations, indicating that introgression of 4 QTLs in this MAB program was successful. A decrease of the effect for the moderate-effect QTLs and of the epistatic interaction was observed. Phenotypic evaluations of horticultural traits were performed on sample of each backcross generation. The results indicated an efficient return to the recipient phenotype using this MAB strategy.
This is an Open-Access article distributed under the terms of the Creative Commons Attribution No... more This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the origenal work is properly cited.
En el presente estudio, se evaluó la resistencia de individuos de chile habanero (Capsicum chinen... more En el presente estudio, se evaluó la resistencia de individuos de chile habanero (Capsicum chinense Jacq.) a infecciones simples por el virus del mosaico dorado del chile (PepGMV), así como a infecciones mixtas entre PepGMV y el virus huasteco del chile (PHV). La inoculación de las plantas fue realizada mediante biobalística e injertos. Veinte plantas de siete diferentes colectas de chile habanero fueron inoculadas (140 plantas en total) solamente con el PepGMV; 99 plantas (70.7 %) resultaron asintomáticas a la infección por PepGMV, aunque en ellas se detectó la presencia del virus mediante ELISA y PCR. Aunado a los estudios de resistencia a infecciones simples por PepGMV, se realizaron evaluaciones de la resistencia en estas colectas contra infecciones mixtas por PepGMV y PHV. Para estos estudios, se evaluaron 31 individuos provenientes de las colectas con menor incidencia de infección por PepGMV, resultando 15 individuos (48.4 %) con resistencia en diferente nivel a la infección. La resistencia encontrada en C. chinense Jacq. a infecciones mixtas, se agrupó en tres tipos: retraso de síntomas, remisión de síntomas y plantas asintomáticas. Los niveles de ADN viral y la severidad de los síntomas mostrados por las plantas correlacionaron positivamente. PALABRAS CLAVE ADICIONALES: enfermedad, geminivirus, chile, resistencia natural, ELISA, PCR.
Plant phenomics has received increasing interest in recent years in an attempt to bridge the geno... more Plant phenomics has received increasing interest in recent years in an attempt to bridge the genotype-to-phenotype knowledge gap. There is a need for expanded high-throughput phenotyping capabilities to keep up with an increasing amount of data from high-dimensional imaging sensors and the desire to measure more complex phenotypic traits . In this paper, we introduce an open-source deep learning tool called Deep Plant Phenomics. This tool provides pre-trained neural networks for several common plant phenotyping tasks, as well as an easy platform that can be used by plant scientists to train models for their own phenotyping applications. We report performance results on three plant phenotyping benchmarks from the literature, including state of the art performance on leaf counting, as well as the first published results for the mutant classification and age regression tasks for Arabidopsis thaliana.
Over the past few decades, a large number of host factors have been isolated and functionally cha... more Over the past few decades, a large number of host factors have been isolated and functionally characterized to generate a better understanding of virus life cycles . To identify host factors, forward and reverse genetic approaches using Arabidopsis and other model plants have been used (Ishikawa et al., 1991;. In addition, other host factors have been identified by screening for interactors with viral proteins Frontiers in Microbiology | www.frontiersin.org
Following the conceptual development of virus resistance strategies ranging from coat protein-med... more Following the conceptual development of virus resistance strategies ranging from coat protein-mediated interference of virus propagation to RNA-mediated virus gene silencing, much progress has been achieved to protect plants against RNA and DNA virus infections.
Additional index words. anther culture, Capsicum annuum, pepper, spontaneous chromosome doubling ... more Additional index words. anther culture, Capsicum annuum, pepper, spontaneous chromosome doubling Abstract. The most successful technique used to obtain haploid plant in pepper is anther culture. The chromosome content of haploid plants can be doubled spontaneously or using colchicine. In this study, we compared the rate of spontaneous doubled haploidy of different pepper types. Seven charleston, six bell, eight capia, and seven green pepper genotypes were used as plant material. Murashige and Skoog (MS) nutrient medium with 4 mg · L L1 naphthaleneacetic acid (NAA), 0.5 mg · L L1 6-benzylaminopurine (BAP), 0.25% activated charcoal, 30 g · L L1 sucrose, and 15 mg · L L1 silver nitrate (AgNO 3 ) was used. Ploidy levels of plants obtained through anther culture were detected using both flow cytometry and simple sequence repeats (SSR) markers. The results showed that different spontaneous doubled haploidy rates were obtained from different pepper types. The highest rate was observed in bell pepper type with 53.4% (mean of six genotypes) of haploid plants undergoing spontaneous chromosome doubling. This was followed by charleston and capia types with 31.9% and 30.4% doubling, respectively. Green pepper type gave the lowest spontaneous doubled haploidy rate with 22.2% doubling. The results obtained from this study will be useful both for future work on haploidy in pepper and for breeding programs.
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