Salinity is a major concern in agriculture since it adversely affects plant growth, development, and yield. Domestication of crops exerted strong selective pressure and reduced their genetic diversity. Meanwhile, wild species continued to adapt to their environment becoming valuable sources of genetic variation, with the potential for enhancing modern crops performance in today’s changing climate. Some wild species are found in highly saline environments; remarkable examples are the endemic wild tomatoes from the Galapagos Islands, forming the Solanum cheesmaniae and Solanum galapagense species (hereafter termed Galapagos tomatoes). These wild tomatoes adapted to thrive in the coastal regions of the Galapagos Islands. The present work includes a thorough characterization of a collection of 67 accessions of Galapagos tomatoes obtained from the Tomato Genetics Resource Center (TGRC). Genotyping-by-sequencing (GBS) was performed to establish the population structure and genetic distance within the germplasm collection. Both species were genetically differentiated, and a substructure was found in S. cheesmaniae dividing the accessions in two groups based on their origin: eastern and western islands. Phenotypic studies were performed at the seedling stage, subjecting seedlings to 200 mM NaCl for 10 days. Various traits were recorded and analysed for their contribution to salinity tolerance, compared to control conditions. Large natural variation was found across the collection in terms of salt stress responses and different possible salt tolerant mechanisms were identified. Six accessions were selected for further work, based on their good performance under salinity. This experiment included scoring several plant growth and yield-related traits, as well as RNA sequencing (RNAseq) at the fruit-ripening stage, under three different NaCl concentrations. Accession LA0421 showed an increased yield of almost 50% in mild salinity (150 mM NaCl) compared to control conditions. The transcriptome data obtained could reveal the genes involved in the salt stress-related yield increase. The knowledge obtained so far will be useful for scientists and breeders to select accessions of interest based on recorded traits. It will allow the use of Galapagos tomatoes as genetic sources for salinity tolerance traits in commercial tomatoes, thereby contributing to feed and nourish the growing human population in the years to come.

Inbred lines for hybrid crop production have been a mainstay of plant breeding. Biotechnological approaches to hasten the process are available including anther culture to halve the genome and protoplast fusion to create hybrids between incompatible partners. We applied these techniques to potato to evaluate their potential for breeding highly heterozygous, cross-pollinating species. Four families of monoploids (2n=1x=12), developed from diploid hybrids with diverse genomic constitutions but heavily favoring Solanum phureja, a primitive cultivated potato, were used in electrofusion experiments to create intermonoploid somatic hybrids (SH). The "monoploid sieve" results in the survival of only those gametes free of lethal and deleterious genes but generates sterile sporophytes, necessitating protoplast fusion for SH development. From six intermonoploid electrofusion combinations, 276 plants were regenerated over 6-9 months. Fusion conditions were optimized. Ploidy was determined by flow-cytometry and SH confirmed by microsatellite analysis. Field evaluations over three years revealed that intermonoploid SH were inferior to cultivars. Dihaploids derived by anther culture of a tetraploid intermonoploid SH were reduced in vigor with an increase in homozygosity, while 2x X 2x sexually derived populations had better yield than the SH, suggesting that producing SH introduced or eliminated factors required for productivity. Molecular analysis of the SH was conducted to examine genomic stability through protoplast isolation and plant regeneration. Sequence specific amplified polymorphism (S-SAP) represents a hybrid system incorporating amplified fragment length polymorphism (AFLP) technology in conjunction with the use of a defined genomic sequence, e.g., retrotransposon display (RD) when the defined sequence is anchored into a consensus sequence of a retrotransposon such as the long terminal repeat (LTR) sequence of Tst1. Parental monoploids, SH and various Solanaceae were evaluated by RD. Fluorescently-labeled retrotransposon-based primers were used in the ALFexpress automated fragment analyzer system. Eleven probes from RD were created for Southern blot analysis and used to verify taxonomic relationships between selected Solanaceae. Blots of intermonoploid somatic hybrids confirmed hybridity and occasional loss of genomic fragments. No activation or replication of retrotransposons was detected. Sequencing of inter-retrotransposon amplified polymorphism (IRAP) and S-SAP fragments revealed that all fragments had the expected Tst1 retroelement and/or the AFLP adaptor sequence. BLAST analysis identified 4 of the 17 fragments sequenced as part of the chloroplast genome, a tobacco anther-specific gene, repetitive DNA, and the phytochrome F gene. / Ph. D.

A hybrid between a highly regenerative diploid clone (BARD 1-3) of Solanum phureja and haploid inducer IVP 101 was transformed with Agrobacterium tumefaciens strain 4404 containing plasmid pHB2892 with genes for green florescent protein (GFP) and kanamycin resistance. Hemizygous primary transformants (To) were produced from three leaf discs: 17 diploid plants from one leaf disc, three and nine tetraploids from the other two leaf discs. GFP expression was observed qualitatively under fluorescence microscopes and quantitatively with a GFP meter. Anther culture of tetraploids produced 29 plants, none with high levels of GFP. Segregation ratios for tetraploid T1 seedlings fit models for single duplex insertions (35 transgenic: 1 non) or double simplex insertions (15 transgenic: 1 non). Diploid T1 seedlings segregated for deleterious traits: dwarfed size and curled leaves, as well as the GFP transgene. Similar segregation patterns in diploid families implied that all diploids may have been from the same transformation event. The cumulative segregation showed the dwarfed and curled plants fit a single recessive gene ratio (3 normal: 1 mutant), and GFP fit a double-copy insertion ratio (15 transgenic: 1 non). There was substantial GFP silencing evidenced by the loss of expression in plants that had originally been selected for high GFP. However, six selections were found to be free of deleterious traits, consistently high expressers of GFP, and producers of stainable pollen with less 2n than IVP 101. / Master of Science

Among viral diseases affecting cultivated tomato, Tomato yellow leaf curl disease (TYLCD) is one of the most devastating. This disease is caused by a complex of viruses of which Tomato yellow leaf curl virus (TYLCV) is regarded as the most important species. Current control strategies to fight viral diseases in tomato are mainly based on genetic resistance derived from wild relatives. In the present thesis, resistance derived from S. chilense and S. peruvianum has been exploited in breeding for resistance to TYLCD. In a previous study, TYLCV-resistant breeding lines derived from LA1932, LA1960 and LA1971 S. chilense accessions were developed. Therefore, the first objective of this thesis was to study the genetic control of the resistance derived from these accessions. With this aim, response to viral infection was assayed in segregating generations derived from the aforementioned resistant lines. The results obtained were compatible with a monogenic control of resistance. Resistance levels were higher in LA1960- and LA1971-derived F2 generations, as shown by slighter symptoms in the resistant plants and a higher number of asymptomatic plants compared with the results obtained in the LA1932-derived F2 generation. It is noteworthy that the level of resistance present in our materials is comparable to or even higher than the levels found in tomato lines homozygous for Ty-1. The response in plants heterozygous for the resistance gene was comparable to the response in homozygous plants for all three sources employed. This implies that the resistance genes derived from all three sources seem to be almost completely dominant. This effect was stronger for LA1971-derived resistance. The results were similar when comparing viral accumulation, as was expected, since a positive correlation was found in these families between viral accumulation and symptom scores. This has important implications in breeding, since the resistance will be used mostly for hybrid development. Our second objective was to map the loci associated with the major resistance genes identified. A total of 263 markers were screened, 94 of them being polymorphic between both species. Recombinant analysis allowed the resistance loci to be localized on chromosome 6, in a marker interval of 25 cM. This interval includes the Ty-1/Ty-3 region, where two S. chilense-derived TYLCD resistance loci were previously mapped. In order to test if the resistance genes identified in our populations were allelic to Ty-1 and Ty-3, further fine mapping was carried out. A total of 13 additional molecular markers distributed on chromosome 6 allowed 66 recombinants to be identified, and the resistance region to be shortened to a marker interval of approximately 950 kb, which overlaps with the Ty-1/Ty-3 region described previously by other authors. Therefore, the results obtained indicate that closely linked genes or alleles of the same gene govern TYLCV resistance in several S. chilense accessions. The third objective of the present thesis was to start the construction of a set of introgression lines (ILs) derived from Solanum peruvianum accession PI 126944 into the cultivated tomato genetic background. Once this collection of ILs is developed, it will represent a powerful tool for exploiting the resistance to different pathogens found in this particular accession in addition to other possible characters of interest. The starting plant material consisted of several segregating generations that were derived from two interspecific hybrids previously obtained by our group. Many crosses and embryo rescue were required to obtain subsequent generations due to the high sexual incompatibility that exists between tomato and PI 126944. Several mature fruits from the most advanced generations produced a few viable seeds, although embryo rescue was also employed to obtain progeny. As only a few plants were obtained by direct backcrossing, additional crosses were made in order to increase the number of descendants. A high degree of incompatibility was also found in crosses between sib plants. A total of 263 molecular markers were tested in some generations, 105 being polymorphic between tomato and PI 126944. Available generations were genotyped with these polymorphic markers in order to determine which alleles of S. peruvianum were already introgressed. On average, 79, 78 and 84 % of the S. peruvianum genome was represented in the pseudo-F2, pseudo-F4 and pseudo-F5 generations, respectively, for the markers analyzed. A reduction in the S. peruvianum genome was observed in more advanced generations, such as BC1 (56 %), pseudo-F2-BC1 (60 %) and pseudo-F3-BC1 (70 %). A greater reduction was observed in the pseudo-F3-BC2 generation (33 %). As a consequence of the reduction in the S. peruvianum genome, a loss of incompatibility was observed in some cases. The S. peruvianum genome was almost completely represented among the different plants of the most advanced generations. An evaluation for resistance to TYLCD and Tomato spotted wilt virus (TSWV) was carried out in some of the advanced generations, some of which were resistant to one or both viruses. In conclusion, we have conducted a successful and deeper exploitation of two wild species with proved resistance to TYLCD, S. chilense and S. peruvianum, identifying and fine mapping new genes of resistance. / Julián Rodríguez, O. (2014). Exploitation of Solanum chilense and Solanum peruvianum in tomato breeding for resistance to Tomato yellow leaf curl disease [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/36867

Barrantes Santamaría, W. (2014). Desarrollo de una genoteca de líneas de introgresión entre Solanum lycopersicum y Solanum pimpinellifolium utilizando herrramientas genomicas de alto rendimiento y detección de QTLs implicados en calidad de fruto [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39102

Tesis por compendio / [ES] La mejora de las especies cultivadas es un área dinámica, sujeta a las necesidades y requerimientos de los diferentes cultivos en cada momento y de las exigencias de productores y consumidores. Una limitación en este proceso de mejora es la diversidad genética existente en los cultivos, debido a cuellos de botella poblacionales, que hacen necesario el uso de especies silvestres. El tomate cultivado (Solanum lycopersicum var. lycopersicum, SLL) surgió a partir de Solanum lycopersicum var. cerasiforme (SLC) que a su vez fue pre-domesticada a partir de Solanum pimpinellifolium (SP). Pese al potencial para la mejora de estas especies, su uso está limitado en gran medida por la falta de información de las colecciones mantenidas en los bancos de germoplasma, principalmente en SLC. Para dar solución a este problema, se ha empleado una colección de germoplasma compuesta por 15 accesiones de SLL, procedentes de México; 27 de SP, procedentes de Perú y Ecuador y 121 de SLC, procedentes de Perú, Ecuador, México y Mesoamérica. Esta colección ha sido sometida a una extensa caracterización fenotípica y genética, lo que ha permitido identificar las regiones de genoma asociadas a caracteres fenotípicos mediante estudios de asociación del genoma completo (GWAS). Además, se han creado poblaciones segregantes F2 para cada una de las entradas de la colección a partir de los híbridos obtenidos con tres parentales diferentes, y estos cruces se han puesto a disposición de la comunidad científica. Este recurso permitirá el estudio del control genético de mutantes de interés en mejora. El estudio realizado con los datos morfológicos ha demostrado la presencia de una gradación morfológica continua entre los tres grupos taxonómicos, y ha permitido la identificación de una serie de caracteres que permiten la diferenciación entre grupos y también entre las distintas procedencias geográficas dentro de cada grupo taxonómico. Los diferentes polimorfismos de nucleótido único (SNPs) fueron anotados con base a la predicción de sus efectos en la secuencia codificantes mediante el programa SnpEff y se llevaron a cabo estudios de GWAS. El análisis genético reveló a Perú y Ecuador como las regiones con mayores niveles de diversidad, tanto en la especie SP como en SLC. Se observó una reducción en el número de variantes SNP en SLC México, que concuerda con la hipótesis de que Mesoamérica sea centro de domesticación y difusión del tomate cultivado. Por último, se constató el proceso de domesticación como la causa de la menor diversidad presente en la especie cultivada. Los estudios GWAS permitieron la identificación de correlaciones genotipo-fenotipo, revelando la asociación entre 107 SNPs y ocho caracteres cuantitativos y un total de 30 SNPs asociados a 7 caracteres cualitativos. Una parte de los SNPs detectados fueron localizados cerca de regiones genómicas ya asociadas con genes y QTLs, otra parte se localizaron en regiones con posibles genes candidatos anotados y el resto de SNPs detectados se corresponden a regiones no descritas previamente, lo que abre el camino a estudios para la detección de nuevos genes candidatos. En esta tesis se muestra la utilidad de la colección de familias segregantes mediante su uso en el estudio del control genético de la presencia y alta densidad de tricomas tipo IV en dos fondos genéticos diferentes, SLL x SP y SP x SLC. En ambos fondos se han detectado dos QTLs principales en los cromosomas 9 y 11. Además, se han detectado señales en los cromosomas 2, 5, 6, 7 y 8, en función de la familia segregante estudiada. Las regiones detectadas en los cromosomas 9 y 11 habían sido previamente descritas en otras especies por regular la densidad de este tipo de tricomas o los niveles de acilazúcares. En ambas regiones hay genes anotados que intervienen en el desarrollo de los tricomas o en la formación de acilazúcares, como aciltransferasas, glicosiltransferasas o los factores de transcripción MYB. / [CA] La millora de les espècies cultivades és una àrea dinàmica, subjecta a les necessitats i requeriments dels diferents cultius a cada moment i de les exigències de productors i consumidors. Una limitació en aquest procés de millora és la diversitat genètica existent en els cultius a causa de diversos colls de botella poblacionals durant la seua domesticació. En aquests casos, les espècies silvestres emparentades revisten un especial interés, podent-se utilitzar com a font de al·lels en la millora genètica. Aquesta circumstància es dona en el cas de la tomaca cultivada (Solanum lycopersicum var. lycopersicum, SLL). Aquesta espècie va sorgir a partir de Solanum lycopersicum var. cerasiforme (SLC), que al seu torn va ser pre-domesticada a partir de Solanum pimpinellifolium (SP). Pese al potencial per a la millora d'aquestes espècies, el seu ús està limitat en gran manera per la falta d'informació de les col·leccions mantingudes en els bancs de germoplasma, principalment SLC. Per a aconseguir l'objectiu anteriorment exposat s'ha emprat una col·lecció de germoplasma composta per 15 accessions de SLL, procedents de Mèxic; 27 de SP, procedents del Perú i l'Equador i 121 de SLC, procedents del Perú, l'Equador, Mèxic i Mesoamèrica. Aquesta col·lecció ha sigut sotmesa a una extensa caracterització fenotípica i genètica, la qual cosa ha permés identificar les regions de genoma associades a caràcters fenotípics mitjançant estudis d'associació del genoma complet (GWAS). A més, s'han creat poblacions segregants F2 per a cadascuna de les entrades de la col·lecció creuant-les amb tres parentals diferents, i aquests creus s'han posat a la disposició de la comunitat científica. Aquest recurs permetrà l'estudi del control genètic de mutants d'interés en millora. Aquesta utilitat s'explora en l'últim capítol de la tesi, on s'estudia el control genètic de la densitat de tricomas en una accessió de l'espècie SP, característica d'interés per conferir resistència a artròpodes. L'estudi realitzat amb les dades morfològiques ha demostrat la presència d'una gradació morfològica contínua entre els tres grups taxonòmics, i ha permés la identificació d'una sèrie de caràcters que permeten la diferenciació entre grups i també entre les diferents procedències geogràfiques dins de cada grup taxonòmic. Els diferents polimorfismes de nucleòtid únic (SNPs) van ser anotats en base a la predicció del seu efecte en la sequència codificant mitjançant el programa SnpEff i es van dur a terme estudis de GWAS. L'anàlisi genètica va revelar al Perú i l'Equador com les regions amb majors nivells de diversitat, tant en l'espècie SP com en SLC. Es va observar una reducció en el nombre de variants SNP en SLC Mèxic, que concorda amb la hipòtesi que Mesoamèrica siga centre de domesticació i difusió de la tomaca cultivada. Finalment, es va constatar el procés de domesticació com la causa de la menor diversitat present en l'espècie cultivada. Els estudis GWAS van permetre la identificació de correlacions genotipe-fenotip, revelant l'associació entre 107 SNPs i huit caràcters quantitatius i un total de 30 SNPs associats a 7 caràcters qualitatius. Una part dels SNPs detectats van ser localitzats prop de regions genòmiques associades amb gens i QTLs o en regions amb possibles gens candidats anotats y la resta de SNPs detectats es corresponen amb regions no descrites prèviament el que obri el camí a estudis per a la detecció de nous gens candidats. La utilitat d'aquestes famílies F2 es demostra en l'últim capítol d'aquesta tesi mitjançant l'estudi de la base genètica de la densitat de tricomas tipus IV. S'estudia el control genètic de la presència i alta densitat de tricomas tipus IV en dos fons genètics diferents, SLL x SP i SP x SLC. En tots dos fons s'han detectat dos QTLs principals en els cromosomes 9 i 11. A més, s'han detectat senyals en els cromosomes 2, 5, 6, 7 i 8, en funció de la família segregant estudiada. Les regions detectades en els cromosomes 9 i 11 havien sigut prèviament descrites en altres espècies per regular la densitat d'aquests tricomas o els nivells de acilazúcares. En totes dues regions hi ha gens anotats que intervenen en el desenvolupament dels tricomas o en la formació de acilsucres, com aciltransferases, glicosiltransferases o els factors de transcripció MYB. / [EN] The improvement of cultivated species is a dynamic field, subject to the needs and requirements of the different crops at different moments as well as to the demands of producers and consumers. A limitation in this improvement process is the amount of genetic diversity available for breeding purposes because of population bottlenecks during their domestication. This circumstance occurs in the case of cultivated tomatoes (Solanum lycopersicum var. lycopersicum, SLL) which evolved from Solanum lycopersicum var. cerasiforme (SLC), which was pre-domesticated from Solanum pimpinellifolium (SP). Despite these species have been used for tomato breeding, their use is still limited due to the lack of detailed information about the collections that are kept in genebanks. With the aim of solve this problem, a germplasm collection has undergone an extensive morphological and genetic characterization. This collection comprises a wide range of geographical origins: includes 15 SLL accessions from Mexico; 27 SP accession from Peru and Ecuador and 121 SLC accessions from Peru, Ecuador, Mesoamerica, and Mexico. Genome-wide association studies (GWAS) were performed to detect genomic candidate regions associated with each agronomic trait. Furthermore, a collection of segregating populations has been developed by crossing the whole collection with a representative accession for each of the three species (SLL, SLC and SP). These populations are available to the scientific community and could be very useful to speed up the validation of candidate genes or to study the genetic control of mutants. This last approach will be explored in the last chapter of this thesis, where the genetic control of density of type IV trichomes is studied. The study carried out with morphological data has demonstrated the presence of a phenotypic variation between our three species. The analysis has allowed the identification of characters which differentiate between species and between different geographical origin within each species. The identified SNPs were annotated, and their putative impacts were predicted by using SnpEff. The lowest number of variants was detected in SLL grups and the highest number of variants was detected in SP. SLC had a variation between SLL and SP, with lower levels in SLC Mexico. This fact agrees with the hypothesis for the domestication and diffusion of cultivated tomato in Mesoamerica. Additionally, GWAS analysis was carried out with this genetic data and revealed significant associations between 107 SNPs and 8 quantitative traits and a total of 30 SNPs associated with 7 qualitative traits. This analysis has allowed the identification of known genomic regions such as the associations between fruit weight and fw2.2 or fw9.2. However, regions with possible novel genes have also been detected such as the case of yellow fruit. These results reinforce the potential of our collection for breeding programmes. The usefulness of F2 populations have been used to determine the genetic control of density of type IV trichomes. During the characterization of this collection, a SP accession (BGV016047) with a high density of type IV trichomes was detected. These trichomes have been described to accumulate different types of chemical substances related to pest resistance. This thesis shows that this character is influenced by environmental factors such as plant and leave age. On the other hand, the genetic control of this character has been studied in two different genetic backgrounds, SLL x SP and SP x SLC. Two main QTLs have been detected in both families, on chromosome 9 and 11. In addition, the different F2 populations have revealed that this character could be under the control of other QTLs on chromosomes 2, 5, 6, 7 and 8. / This research was supported by the National Natural Science Foundation of USA Varitome project (NSF IOS 1564366). / Mata Nicolás, E. (2021). Utilización de una colección de germoplasma de tomate para la identificación de genes de interés [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172639 / Compendio

No description available.

Tesis por compendio / [ES] La berenjena (Solanum melongena) es una hortaliza muy importante en muchas áreas tropicales y subtropicales del mundo. Es la tercera solanácea más producida a nivel mundial, pero a pesar de su importancia los recursos genéticos y las herramientas biotecnológicas para su investigación no han sido desarrollados lo suficiente. Con la actual situación de cambio climático, muchas de las áreas donde se produce este cultivo están sufriendo modificaciones dramáticas en el ambiente y la climatología. Esto está ocasionando una reducción de los rendimientos de este cultivo que cada vez se ven más afectados por la aparición de nuevas enfermedades, plagas, malezas, pérdida en la fertilidad de los suelos, mayor prevalencia de sequía y salinidad, así como el incremento de las temperaturas. La berenjena se encuentra en una situación de vulnerabilidad ante estos cambios debido a los efectos de cuello de botella genético acontecidos durante su domesticación y a la disponibilidad limitada de recursos genéticos accesibles para su mejora genética. En un primer gran bloque de esta tesis, mediante el uso de especies silvestres relacionadas con la berenjena, se ha iniciado el desarrollo de una colección de líneas de introgresión (ILs). Utilizando tres especies representantes de los tres grupos de germoplasma de la berenjena (S. insanum del germoplasma primario, S. dasyphyllum del germoplasma secundario y S. elaeagnifolium del germoplasma terciario) se ha ampliado el fondo genético de este cultivo. Estas especies, han sido seleccionadas por sus extraordinarias capacidades de adaptación a climas áridos, suelos secos y tolerancia a plagas y enfermedades. Reintroduciendo estos genes en el genoma de la berenjena cultivada hemos desarrollado un conjunto de materiales élite, que ponen a disposición de los investigadores y mejoradores nuevos recursos genéticos para la mejora genética de este cultivo. También hemos desarrollado un modelo experimental (Micro-Mel) a partir de materiales de introgresión con la especie S. anguivi. Este modelo consiste en una berenjena de tipo compacto y crecimiento determinado con floración y cuajado múltiple y puede ayudar a desarrollar experimentos rápidos, así como acelerar los ciclos generacionales en los proyectos de mejora. En otro segundo gran bloque de este trabajo, hemos desarrollado una serie de herramientas biotecnológicas que van a permitir desarrollar otro tipo de investigaciones para la adaptación al cambio climático en berenjena. En primer lugar, frente a la necesidad de un protocolo eficiente de regeneración in vitro para poder llevar a cabo experimentos de transformación y edición genética en la berenjena, se ha desarrollado con éxito un protocolo de alto rendimiento basado en el uso del ribósido de zeatina y que presenta una baja dependencia del factor genotipo. Como resultado derivado de este primer desarrollo, diseñamos otro protocolo para la obtención de organismos poliploides en berenjena sin la necesidad de utilizar agentes antimitóticos para la duplicación de su genoma. Empleando los distintos niveles de ploidía presente en algunos tejidos jóvenes (patrón polisomático) conseguimos desarrollar plantas tetraploides in vitro a través de la regeneración directa a partir de estas células, suponiendo una nueva vía hacia el desarrollo de plantas triploides sin semillas. Finalmente, la última herramienta de apoyo a la mejora de la berenjena que se ha desarrollado en esta tesis doctoral ha sido una herramienta basada en la inteligencia artificial para la identificación de estadios de desarrollo de las células precursoras del polen en retrocruces avanzados con especies silvestres. Con esto se ha conseguido optimizar los protocolos de androgénesis empleados para la producción de plantas dobles haploides, automatizando y haciendo más eficiente la selección de anteras con estadios inducibles y por tanto incrementando la tasa de plantas dobles haploid / [CA] L'albergínia (Solanum melongena) és una hortalissa molt important en moltes zones tropicals i subtropicals del món. És la tercera solanàcia més produïda en l'àmbit mundial, però malgrat la seua importància els recursos genètics i les ferramentes biotecnològiques per a la seua investigació no han sigut desenvolupades el suficient. Amb l'actual situació de canvi climàtic, moltes de les zones on es produeix aquest cultiu estan patint modificacions dramàtiques al seu ambient i climatologia. Açò ocasiona una reducció dels rendiments d'aquest cultiu que cada vegada es veu més afectat per l'aparició de noves malalties, plagues, males herbes, pèrdua de la fertilitat del sol, major prevalença de la sequera i salinitat, així com l'increment de les temperatures. L'albergínia es troba a una situació de vulnerabilitat davant aquests canvis debuts als efectes de l'erosió genètica ocasionats durant la seua domesticació i a la disponibilitat limitada de recursos genètics accessibles per a la seua millora genètica. En un primer gran bloc d'aquesta tesi, mitjançant l'ús d'espècies silvestres relacionades amb l'albergínia, s'ha iniciat el desenvolupament d'una col·lecció de línies de introgressió (ILs). Utilitzant tres espècies representants dels tres grups de germoplasma de l'albergínia (S. insanum del germoplasma primari, S. dasyphyllum del germoplasma secundari i S. elaeagnifolium del germoplasma terciari) s'ha ampliat el fons genètic d'aquest cultiu. Aquestes espècies, han sigut seleccionades per les seues extraordinàries capacitats d'adaptació a climes àrids, sòls secs i tolerància a plagues i malalties. Reintroduint aquests gens en el genoma de l'albergínia cultivada hem desenvolupat un conjunt de materials elit, que posen a la disposició dels investigadors i milloradors nous recursos genètics per a la millora genètica d'aquest cultiu. També hem desenvolupat un model experimental (Micro-Mel) a partir de materials de introgressió amb l'espècie S. anguivi. Aquest model consisteix en una albergínia de tipus compacte i creixement determinat amb floració i quallat múltiple i pot ajudar a desenvolupar experiments ràpids, així com accelerar els cicles generacionals en els projectes de millora. En un altre segon gran bloc d'aquest treball, hem desenvolupat una sèrie d'eines biotecnològiques que permetran desenvolupar un altre tipus d'investigacions per a l'adaptació al canvi climàtic en albergínia. En primer lloc, enfront de la necessitat d'un protocol eficient de regeneració in vitro per a poder dur a terme experiments de transformació i edició genètica en l'albergínia, s'ha desenvolupat amb èxit un protocol d'alt rendiment basat en l'ús del ribòsid de zeatina i que presenta una baixa dependència del factor genotip. Com a resultat derivat d'aquest primer desenvolupament, dissenyem un altre protocol per a l'obtenció d'organismes poliploids en albergínia sense la necessitat d'utilitzar agents antimitòtics per a la duplicació del seu genoma. Emprant els diferents nivells de ploidía present en alguns teixits joves (patró polisomàtic) aconseguim desenvolupar plantes tetraploids in vitro a través de la regeneració directa a partir d'aquestes cèl·lules, suposant una nova via cap al desenvolupament de plantes triploids sense llavors. Finalment, l'última eina de suport a la millora de l'albergínia que s'ha desenvolupat en aquesta tesi doctoral ha sigut una eina basada en la intel·ligència artificial per a la identificació d'estadis de desenvolupament de les cèl·lules precursores del pol·len en retrocreuaments avançats amb espècies silvestres. Amb això s'ha aconseguit optimitzar els protocols d'androgènesi emprats per a la producció de plantes dobles haploids, automatitzant i fent més eficient la selecció d'anteres amb estadis induïbles i per tant incrementant la taxa de plantes dobles haploids produïdes. / [EN] Eggplant (Solanum melongena) is a very important vegetable in many tropical and subtropical areas of the world. It is the third most produced Solanaceae in the world, but despite its importance, genetic resources and biotechnological tools for research have not been sufficiently developed. With the current climate change situation, many of the areas where this crop is produced are undergoing dramatic changes in the environment and the weather. This is causing a reduction in the yields of this crop that are increasingly affected by the appearance of new diseases, pests, weeds, loss of soil fertility, greater prevalence of drought and salinity, as well as the increase in temperatures. The eggplant is in a situation of vulnerability to these changes due to the genetic bottleneck effects that occurred during its domestication and the limited availability of accessible genetic resources for its genetic improvement. In a first large block of this thesis, using wild species related to eggplant, the development of a collection of introgression lines (ILs) has been started. Using three species representing the three groups of eggplant germplasm (S. insanum from primary germplasm, S. dasyphyllum from secondary germplasm and S. elaeagnifolium from tertiary germplasm) the genetic background of this crop has been expanded. These species have been selected for their extraordinary capacities to adapt to arid climates, dry soils and tolerance to pests and diseases. By reintroducing these genes into the genome of cultivated eggplant, we have developed a set of elite materials that make new genetic resources available to researchers and breeders for the genetic improvement of this crop. We have also developed an experimental model (Micro-Mel) from introgression materials with the species S. anguivi. This model consists of an eggplant of compact type and determined growth with multiple flowering and fruit set and can help to develop rapid experiments, as well as accelerate generational cycles in improvement projects. In another second large block of this work, we have developed a series of biotechnological tools that will allow the development of other types of research for adaptation to climate change in eggplant. In the first place, in view of the need for an efficient in vitro regeneration protocol to be able to carry out transformation and gene editing experiments in eggplant, a high-throughput protocol based on the use of zeatin riboside and which presents a low dependence on the genotype factor was developed. As a result, derived from this first development, we designed another protocol to obtain polyploid organisms in eggplant without the need to use antimitotic agents for the duplication of their genome. Using the different levels of ploidy present in some young tissues (polysomatic pattern) we managed to develop tetraploid plants in vitro through direct regeneration from these cells, assuming a new path towards the development of triploid seedless plants. Finally, the last tool to support the breeding of eggplant that has been developed in this doctoral thesis has been a tool based on artificial intelligence for the identification of stages of development of pollen precursor cells in advanced backcrosses with wild species. With this it has been possible to optimize the androgenesis protocols used to produce double haploid plants, automating, and making the selection of anthers with inducible stages more efficient and therefore increasing the rate of double haploid plants produced. / García Fortea, E. (2020). Desarrollo de materiales de pre-mejora y herramientas biotecnológicas para la adaptación de la berenjena al cambio climático [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/160059 / Compendio

Activation-tagging is a functional genomics technique where strong enhancers are inserted randomly into target genomes to over-activate endogenous genes. Phenotypes of interest can be selected for investigation of genetic factors contributing to the mutant phenotype. From initial screens of a population of activation-tagged potato, a mutant with chocolate-coloured tuber skin has been identified. In this thesis, a novel sequence capture method for identifying T-DNA loci in activation tagged potato was used to characterize chocolate’s single T-DNA insertion locus. Transcriptome analysis of tuber periderm tissue was used to identify major processes occurring in the chocolate mutant. Our data suggest activation of a chitin-binding receptor-like kinase located 65 kb from T-DNA insert may cause activation of immune signaling pathways in chocolate. The present work explores a putative model of transcriptional and cellular responses involved in gain-of-function immune receptor activation. Selectively, these findings illustrate the periderm tissue as an important area of defense charged against biotic and abiotic stresses. Periderm development and anatomy are highly important for tuber storage. Further characterization of potato tuber periderm may contribute knowledge to model periderm systems and have implications for molecular breeding strategies to improve tuber storage quality. / Thesis (Master, Biology) -- Queen's University, 2012-09-27 11:45:16.478

In this study the growth and yield response of Solanum retroflexum Dun. (nightshade) and Brassica rapa L. subsp. chinensis (non-heading Chinese cabbage) to N, P and K availability in the soil and the interaction effects of these three nutrients were determined by means of pot experiments in a greenhouse. S. retroflexum was most sensitive to the availability of nitrogen in the soil. Sufficient nitrogen needed to be available to achieve optimum growth but adding too much adversely affected biomass production, suggesting a fairly narrow optimum range for nitrogen availability. The production of the crop was also dependent on the adequate availability of phosphorus and potassium but any adverse effects due to excess availability were less distinct than for nitrogen. In the case of B. rapa subsp. chinensis, an optimum availability range was identified for N and K and a critical level of availability for P. The decline in biomass production caused by adding N in excess of the optimum was reversed by applying both P and K at rates that were in excess of the respective optima.