Inheritance of Fruit Red-Flesh Patterns in Peach

Fruit color is an important trait in peach from the point of view of consumer preference, nutritional content, and diversification of fruit typologies. Several genes and phenotypes have been described for peach flesh and skin color, and although peach color knowledge has increased in the last few years, some fruit color patterns observed in peach breeding programs have not been carefully described. In this work, we first describe some peach mesocarp color patterns that have not yet been described in a collection of commercial peach cultivars, and we also study the genetic inheritance of the red dots present in the flesh (RDF) and red color around the stone (CAS) in several intra- and interspecific segregating populations for both traits. For RDF, we identified a QTL at the beginning of G5 in two intraspecific populations, and for CAS we identified a major QTL in G4 in both an intraspecific and an interspecific population between almond and peach. Finally, we discuss the interaction between these QTLs and some other genes previously identified in peach, such as dominant blood flesh (DBF), color around the stone (Cs), subacid (D) and the maturity date (MD), and the implications for peach breeding. The results obtained here will help peach germplasm curators and breeders to better characterize their plant materials and to develop an integrated system of molecular markers to select these traits

Inheritance of Fruit Red-Flesh Patterns in Peach

Fruit color is an important trait in peach from the point of view of consumer preference, nutritional content, and diversification of fruit typologies. Several genes and phenotypes have been described for peach flesh and skin color, and although peach color knowledge has increased in the last few years, some fruit color patterns observed in peach breeding programs have not been carefully described. In this work, we first describe some peach mesocarp color patterns that have not yet been described in a collection of commercial peach cultivars, and we also study the genetic inheritance of the red dots present in the flesh (RDF) and red color around the stone (CAS) in several intra- and interspecific segregating populations for both traits. For RDF, we identified a QTL at the beginning of G5 in two intraspecific populations, and for CAS we identified a major QTL in G4 in both an intraspecific and an interspecific population between almond and peach. Finally, we discuss the interaction between these QTLs and some other genes previously identified in peach, such as dominant blood flesh (DBF), color around the stone (Cs), subacid (D) and the maturity date (MD), and the implications for peach breeding. The results obtained here will help peach germplasm curators and breeders to better characterize their plant materials and to develop an integrated system of molecular markers to select these traits.info:eu-repo/semantics/publishedVersio

Anti-angiogenic therapy for cancer: Current progress, unresolved questions and future directions

Tumours require a vascular supply to grow and can achieve this via the expression of pro-angiogenic growth factors, including members of the vascular endothelial growth factor (VEGF) family of ligands. Since one or more of the VEGF ligand family is overexpressed in most solid cancers, there was great optimism that inhibition of the VEGF pathway would represent an effective anti-angiogenic therapy for most tumour types. Encouragingly, VEGF pathway targeted drugs such as bevacizumab, sunitinib and aflibercept have shown activity in certain settings. However, inhibition of VEGF signalling is not effective in all cancers, prompting the need to further understand how the vasculature can be effectively targeted in tumours. Here we present a succinct review of the progress with VEGF-targeted therapy and the unresolved questions that exist in the field: including its use in different disease stages (metastatic, adjuvant, neoadjuvant), interactions with chemotherapy, duration and scheduling of therapy, potential predictive biomarkers and proposed mechanisms of resistance, including paradoxical effects such as enhanced tumour aggressiveness. In terms of future directions, we discuss the need to delineate further the complexities of tumour vascularisation if we are to develop more effective and personalised anti-angiogenic therapies. © 2014 The Author(s)

Understanding and Exploiting Almond Genetic Diversity for Peach Breeding : Development of a Peach-Almond Introgression Line collection and Fine Mapping of Key Fruit-Related Genes

El presseguer (Prunus persica), un dels arbres fruiters més importants, té baixos nivells de variabilitat genètica. Una manera d'augmentar la seva diversitat és mitjançant la introducció d'al·lels nous d'altres espècies properes del gènere Prunus, silvestres o cultivades. Per a aquest estudi, es va triar l'ametller (P. dulcis), i els resultats obtinguts es basen en un encreuament inicial realitzat a finals de la dècada de 1970 com a part d'un programa de millora de portaempelts utilitzant l'ametller 'Texas' com a parental femení i el presseguer 'Earlygold' com a parental masculí. Més tard (2006), es va obtenir una nombrosa primera generació de retroencreuament (BC1) amb 'Earlygold', i es va desenvolupar una estratègia de millora basada en marcadors per tal d'obtenir plantes amb un o uns pocs fragments cromosòmics d'ametller en el fons de presseguer només en dues generacions de BC. En aquesta tesi, basada en la disponibilitat prèvia d'un conjunt de línies BC2 amb 2-3 introgressions d'ametller, hem desenvolupat una col·lecció completa de línies d'introgressió (IL), formada per 67 línies que tenen un sol fragment d'ametller en el fons de presseguer; 39 ILs amb la introgressió d'ametller en heterozigosi, que abasta el 99% del genoma de l'ametller, i 28 amb fragments d'ametller en homozigosi, amb un 83% de cobertura del genoma de l'ametller. Aquestes col·leccions van ser analitzades per a alguns dels gens majors que s'esperava que segreguessin i per a alguns dels QTLs relacionats amb caràcters del fruit detectats anteriorment en progènies de 'Texas' × 'Earlygold'. A causa de la naturalesa parcialment heterozigòtica del parental recurrent, 'Earlygold', que s'espera que se segregui en la col·lecció d'ILs, es va realitzar una anàlisi de QTLs en la seva F2 per 24 caràcters, on es van identificar un total de 26 QTLs. Només un QTL, el que determina a la data de maduresa en el cromosoma 4 i que co-localitza amb altres QTLs per caràcters del fruit i del color de les fulles, es va considerar com potencialment problemàtic per a l'anàlisi de les ILs. La part final de la tesi consisteix en el mapatge fi de tres gens majors detectats en les poblacions de presseguer × ametller: dos que expliquen una part important de les diferències entre el fruit d'un préssec i una ametlla (Alf/alf que determina el mesocarpi gruixut i que madura del presseguer i Jui/jui que fa que aquest mesocarpi sigui sucós), i un tercer gen, DBF2/dbf2, que produeix un fruit de carn vermella conferit per l'al·lel de l'ametller. Aquest estudi va implicar una cerca a gran escala de recombinants en vàries poblacions segregants i va permetre localitzar Alf, Jui i DBF2 en fragments d'ADN curts, entre 10-392 kb, incloent de 4 a 95 gens candidats posicionals. Els candidats més probables per als gen Alf (Prupe.4G187100 i Prupe.4G188700) i DBF2 (Prupe.1G519800) es van trobar a partir de l'anàlisi de variants i la predicció dels seus efectes obtinguts de l'estudi de les dades de reseqüència d'ADN i d'anàlisi d'expressió de 'Texas', 'Earlygold' i alguns dels seus descendents amb diferents fenotips, proporcionant una informació útil per a la seva futura clonació com a gens responsables dels fenotips observats.El melocotonero (Prunus persica), uno de los frutales más importantes, tiene un nivel de variabilidad genética bajo. Una de las formas de mejorar su diversidad es mediante la introducción de nuevos alelos de especies silvestres o cultivadas próximas del género Prunus. Para este estudio, se usó el almendro (P. dulcis) como donante de variabilidad, tomando como punto de partida un híbrido realizado a fines de la década de 1970 como parte de un programa de mejora de portainjertos con el almendro 'Texas' como parental femenino y el melocotonero 'Earlygold' como parental masculino. Más tarde (2006), se generó un numeroso retrocruzamiento (BC1) de este híbrido con 'Earlygold', y se desarrolló una estrategia de mejora basada en marcadores para obtener plantas con uno o unos pocos fragmentos cromosómicos de almendro en el fondo genético del melocotonero solo en dos generaciones de BC. En esta tesis, basándonos en la disponibilidad de un juego de líneas BC2 con 2-3 introgresiones de almendro, hemos desarrollado una colección completa de líneas de introgresión (ILs), formada por 67 ILs con un único fragmento de almendro en el fondo genético del melocotonero: 39 con la introgresión de almendro en heterocigosis, cubriendo el 99% del genoma del almendro, y 28 con fragmentos de almendro homocigotos, con 83% de cobertura. Estas colecciones se analizaron para algunos de los genes mayores que se espera que estén segregando en las ILs y para algunos de los QTLs de fruto previamente detectados en descendencias basadas en 'Texas' × 'Earlygold'. Debido a la naturaleza parcialmente heterocigótica del parental recurrente, 'Earlygold', que se espera que segregue en la colección de ILs, se realizó un análisis de 24 caracteres en su F2, identificando un total de 26 QTLs. Un QTL mayor para época de maduración situado en el cromosoma 4, que co-localizaba con otros QTLs de caracteres relacionados con la fruta y la hoja se consideró la única región potencialmente problemática para el análisis de las ILs. La parte final de la tesis consiste en el mapeo fino de tres genes mayores detectados en las poblaciones de almendro × melocotonero: dos que explican una parte importante de las diferencias entre el fruto del melocotonero y el almendro (Alf/alf que determina el mesocarpio grueso y que madura del melocotón y Jui/jui que determina la jugosidad de este mesocarpio), y un tercer gen, DBF2/dbf2, que produce un fruto de carne roja conferido por el alelo del almendro. Este estudio implicó la búsqueda a gran escala de recombinantes en varias poblaciones segregantes y resultó en la ubicación de los genes Alf, Jui y DBF2 en fragmentos de ADN cortos, de 10-392 kb, que contenían entre 4 y 95 genes candidatos posicionales. Los candidatos más probables para Alf (Prupe.4G187100 y Prupe.4G188700) y DBF2 (Prupe.1G519800) fueron identificados usando análisis de variantes y la predicción de sus efectos usando datos de resecuencia de 'Texas' y 'Earlygold' y de expresión génica, proporcionando una base sólida para su clonación futura como genes responsables de los fenotipos observados.Peach (Prunus persica), one of the most important temperate fruit crops, has low levels of genetic variability. One of the ways to improve its diversity is by introgression of novel alleles from a closely related wild or cultivated Prunus species. For this study, almond (Prunus dulcis) was chosen, and the results obtained are based on an initial cross performed in the late 1970's as part of a rootstock breeding program using almond cultivar 'Texas' as female parent and peach cultivar 'Earlygold' as male parent. Later (2006), a large backcross one (BC1) generation to 'Earlygold' was produced, and a marker-based breeding strategy was developed to obtain plants with one or a few almond chromosomal fragments in the peach background only with two BC generations. In this thesis, based on the previous production of a set of BC2 lines with 2-3 almond introgressions, we have developed a complete introgression line (IL) collection, consisting of 67 lines that have a single almond fragment in the peach background; 39 ILs with the almond introgression in heterozygosis, covering 99% of the almond genome, and 28 with homozygous almond fragments, with 83% almond coverage. These collections were analyzed for some of the major genes that were expected to segregate and for some of the fruit-related QTLs that had been detected earlier with 'Texas' × 'Earlygold'-based progenies. Due to the partly heterozygous nature of our recurrent parent, 'Earlygold', which is expected to segregate in the IL collection, a QTL analysis was performed using its F2 progeny in a large set of 24 traits, where a total of 26 QTLs were identified. Only a major QTL for maturity date on chromosome 4, co-locating with other fruit-related characters and leaf color at senescence QTLs was considered as of potentially concern for IL analysis. The final part of the thesis involves the fine mapping of three major genes detected in the almond x peach populations: two that explain an important part of the differences between a peach and an almond fruit (Alf/alf that determines the thick and ripening mesocarp of peach and Jui/jui that determines the juciness of this mesocarp), and a third gene (DBF2/dbf2) that produces a red-fleshed fruit conferred by the almond allele. This study involved large-scale recombinant screening in various segregating populations and resulted in the location of Alf, Jui and DBF2 genes in DNA fragments as short as 10-392 kb including 4 to 95 positional candidate genes. Most probable candidates were identified for Alf (Prupe.4G187100 and Prupe.4G188700) and DBF2 (Prupe.1G519800) genes from the analysis of variants and the prediction of their effects obtained from the study of 'Texas' and 'Earlygold' DNA resequence data and gene expression analysis, providing a solid basis for their future cloning as responsible genes for the observed phenotypes

Exploring the almond genome for alleles useful in peach improvement

Trabajo presentado al Seminario del CRAG (Internal Webinar), celebrado Online el 4 de septiembre de 2020.Peer reviewe

Development of an introgression line (IL) collection of almond genome fragments into the peach genetic background

Resumen del trabajo presentado a la 10th Rosaceae Genomic Conference (RGC), celebrada de forma virtual del 9 al 11 de diciembre de 2020.Peer reviewe

Exploring the almond genome for alleles useful in peach improvement

Trabajo presentado al Congreso European Plant Science Retreat (EPSR), celebrado del 8 al 10 de julio de 2019 en Nottingham (UK)

Comparative QTL analysis in peach ‘Earlygold’ F2 and backcross progenies

Based on detailed maps, DNA sequences and phenotypic data, there is a great deal of information on the genetics and genomics of ‘Earlygold’, a historical peach cultivar from the US. The F2 between ‘Texas’ almond and ‘Earlygold’ peach (T × E) was used to construct the first saturated peach linkage map that later became the reference map for the Prunus genus. This population and the first backcross ('Texas’ × ‘Earlygold’) × ‘Earlygold’ (T1E) yielded information on QTLs for a large number of agronomic traits, and T1E is being used as the basis for constructing a set of introgression lines of ‘Texas’ fragments into the ‘Earlygold’ background, currently in progress. This paper describes the construction of a high-density SNP map for ‘Earlygold’ using an F2 population, and the QTL analysis of 24 traits. Results of maps and QTLs are compared with those from the ‘Earlygold’ parent of the T1E map, using the same set of markers and characters. Results show major differences between the two progenies in terms of numbers of markers mapped and the capability of detecting QTLs, with a large increase in the resolution of maps and QTLs when using the F2 progeny compared to the T1E pseudo-testcross. In addition, we provide data on leaf senescence color, studied for the first time in peach, with two consistent QTLs located in the same position as other color-related genes and QTLs.This research has been partly funded by grant PID2019–110599RR-I00 from the Spanish Ministry of Science and Innovation, by the European Union Program PRIMA (project FREECLIMB no. PCI2019–103670), Severo Ochoa Program for Centres of Excellence in R&D 201–2019 SEV-2015–0533 and CERCA Program-Generalitat de Catalunya.Peer reviewe

Comparative QTL analysis in peach ‘Earlygold’ F2 and backcross progenies

Based on detailed maps, DNA sequences and phenotypic data, there is a great deal of information on the genetics and genomics of ‘Earlygold’, a historical peach cultivar from the US. The F2 between ‘Texas’ almond and ‘Earlygold’ peach (T × E) was used to construct the first saturated peach linkage map that later became the reference map for the Prunus genus. This population and the first backcross (’Texas’ × ‘Earlygold’) × ‘Earlygold’ (T1E) yielded information on QTLs for a large number of agronomic traits, and T1E is being used as the basis for constructing a set of introgression lines of ‘Texas’ fragments into the ‘Earlygold’ background, currently in progress. This paper describes the construction of a high-density SNP map for ‘Earlygold’ using an F2 population, and the QTL analysis of 24 traits. Results of maps and QTLs are compared with those from the ‘Earlygold’ parent of the T1E map, using the same set of markers and characters. Results show major differences between the two progenies in terms of numbers of markers mapped and the capability of detecting QTLs, with a large increase in the resolution of maps and QTLs when using the F2 progeny compared to the T1E pseudo-testcross. In addition, we provide data on leaf senescence color, studied for the first time in peach, with two consistent QTLs located in the same position as other color-related genes and QTLs.info:eu-repo/semantics/publishedVersio

Inheritance of Fruit Red-Flesh Patterns in Peach

Fruit color is an important trait in peach from the point of view of consumer preference, nutritional content, and diversification of fruit typologies. Several genes and phenotypes have been described for peach flesh and skin color, and although peach color knowledge has increased in the last few years, some fruit color patterns observed in peach breeding programs have not been carefully described. In this work, we first describe some peach mesocarp color patterns that have not yet been described in a collection of commercial peach cultivars, and we also study the genetic inheritance of the red dots present in the flesh (RDF) and red color around the stone (CAS) in several intra- and interspecific segregating populations for both traits. For RDF, we identified a QTL at the beginning of G5 in two intraspecific populations, and for CAS we identified a major QTL in G4 in both an intraspecific and an interspecific population between almond and peach. Finally, we discuss the interaction between these QTLs and some other genes previously identified in peach, such as dominant blood flesh (DBF), color around the stone (Cs), subacid (D) and the maturity date (MD), and the implications for peach breeding. The results obtained here will help peach germplasm curators and breeders to better characterize their plant materials and to develop an integrated system of molecular markers to select these traits