The main topic of research was to characterise genes/QTLs associated with the resistance traits against one of the most feared telluric pathogens affecting eggplant: Fusarium oxysporum f. sp. Melongenae (Fom). Different genetic materials and populations available at CREA-GB (Core collections, RIL and Introgressed lines populations) were used for this purpose, and they were submitted to phenotyping for Fom tolerance/resistance (artificial inoculation) and genotyping by using different types of molecular markers. These activities were made possible thanks to the availability of information regarding a) QTL loci for the resistance already mapped in a F2 population obtained from the cross between the two eggplant lines 305E40 x 67/3, b) a high-quality genome sequence of one mapping parent (67/3 line), c) a 35X Illumina sequencing of the other parent 305E40, and d) a 5x Illumina sequencing data of each RIL progeny from the hybrid 305E40 x 67/3. In the present thesis, a mapping study of the QTLs associated with the Fusarium tolerance trait previously located on chromosome 11, and Fusarium resistance trait previously located on chromosome 2, together with a BSA seq analysis, made it possible to identify 3 and 10 candidate genes respectively within the confidence interval of the QTLs. Chromosome 11 involvement in the partial resistance to Fom was confirmed by the high sensitivity of two BC6-BC6S1 progenies of the S. tomentosum introgression population carrying introgressed fragments by the wild parent on CH11, which replaced the S. melongenae 67/3 resistance QTL. In addition, within the eggplant collection, 13 accessions totally resistant to Fom were identified which could represent new sources of resistance traits and be employed into breeding programs of eggplant. Finally, to genetically dissect the positive or negative effect of NO3- or NH4+ nitrogen supply at the early stage of interaction with Fusarium oxysporum in two genotypes was studied a transcriptome analysis was carried out. RNA seq analysis identified a conspicuous number of reciprocal and distinctive genes found in each pairwise comparison from the DEGs, however further analysis is required to better define their biological role
L'argomento principale della ricerca è stato quello di caratterizzare i geni/QTL associati ai tratti di resistenza contro uno dei patogeni tellurici più temuti che colpiscono le melanzane: Fusarium oxysporum f. sp. Melongenae (Fom). Per questo scopo sono stati utilizzati diversi materiali genetici e popolazioni disponibili al CREA-GB (Core collections, RIL, e Introgressed lines), e sono stati sottoposti a fenotipizzazione per la tolleranza/resistenza a Fom (inoculazione artificiale) e genotipizzazione con diversi tipi di marcatori molecolari. Queste attività sono state possibili grazie alla disponibilità di informazioni riguardanti: a) i loci QTL per la resistenza già mappati in una popolazione F2 ottenuta dall'incrocio tra le due linee di melanzane 305E40 x 67/3, b) una sequenza genomica di alta qualità di un genitore mappante (linea 67/3), c) un sequenziamento illumina 35X dell'altro genitore 305E40, e d) un sequenziamento illumina 5x di ogni progenie RIL dell'ibrido 305E40 x 67/3. Nella presente tesi, uno studio di mappatura dei QTLs associati al tratto di tolleranza al Fusarium precedentemente localizzato sul cromosoma 11, e al tratto di resistenza totale al Fusarium localizzato sul cromosoma 2, insieme ad un’analisi BSA seq, ha permesso di individuare rispettivamente 3 e 10 geni candidati all’interno dell’intervallo di confidenza dei QTLs. Il coinvolgimento del cromosoma 11 è stato inoltre confermato attraverso l'impiego di due progenie BC6- BC6S1 della popolazione di introgressione da S. tomentosum, dove è stata rilevata una risposta di suscettibilità marcata all'infezione in quanto portano frammenti introgressi dal parentale selvatico proprio sul CH11. Inoltre, all’interno di una Core collection di 350 accessioni rappresentative dell'intera variabilità del germoplasma della melanzana ne sono state individuate 13 totalmente resistenti a Fom che potrebbero essere impiegate in programmi di breeding. Infine, è stato studiato l’effetto positivo o negativo, rispettivamente, della fornitura di azoto NO3- o NH4+ nella fase iniziale dell'interazione con Fusarium oxysporum in due genotipi. L'analisi RNAseq ha identificato un numero cospicuo di geni condivisi ed esclusivi trovati in ogni confronto a coppie dai DEG, ma sono necessarie ulteriori analisi per definire meglio il loro ruolo biologico
Genetic characterization of eggplant (Solanum melongena L.) tolerance/resistance to soil-borne diseases / Tassone, Maria Rosaria. - (2022 Oct 10).
Genetic characterization of eggplant (Solanum melongena L.) tolerance/resistance to soil-borne diseases
2022-10-10
Abstract
The main topic of research was to characterise genes/QTLs associated with the resistance traits against one of the most feared telluric pathogens affecting eggplant: Fusarium oxysporum f. sp. Melongenae (Fom). Different genetic materials and populations available at CREA-GB (Core collections, RIL and Introgressed lines populations) were used for this purpose, and they were submitted to phenotyping for Fom tolerance/resistance (artificial inoculation) and genotyping by using different types of molecular markers. These activities were made possible thanks to the availability of information regarding a) QTL loci for the resistance already mapped in a F2 population obtained from the cross between the two eggplant lines 305E40 x 67/3, b) a high-quality genome sequence of one mapping parent (67/3 line), c) a 35X Illumina sequencing of the other parent 305E40, and d) a 5x Illumina sequencing data of each RIL progeny from the hybrid 305E40 x 67/3. In the present thesis, a mapping study of the QTLs associated with the Fusarium tolerance trait previously located on chromosome 11, and Fusarium resistance trait previously located on chromosome 2, together with a BSA seq analysis, made it possible to identify 3 and 10 candidate genes respectively within the confidence interval of the QTLs. Chromosome 11 involvement in the partial resistance to Fom was confirmed by the high sensitivity of two BC6-BC6S1 progenies of the S. tomentosum introgression population carrying introgressed fragments by the wild parent on CH11, which replaced the S. melongenae 67/3 resistance QTL. In addition, within the eggplant collection, 13 accessions totally resistant to Fom were identified which could represent new sources of resistance traits and be employed into breeding programs of eggplant. Finally, to genetically dissect the positive or negative effect of NO3- or NH4+ nitrogen supply at the early stage of interaction with Fusarium oxysporum in two genotypes was studied a transcriptome analysis was carried out. RNA seq analysis identified a conspicuous number of reciprocal and distinctive genes found in each pairwise comparison from the DEGs, however further analysis is required to better define their biological roleFile | Dimensione | Formato | |
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