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| Author(s): |
Estela Araujo Costa
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2015-02-26 |
| Examining board members: |
Anete Pereira de Souza;
Gabriel Rodrigues Alves Margarido;
Mirian Perez Maluf;
Eugenio Cesar Ulian;
Rosangela Maria Simeão Resende
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| Advisor: | Anete Pereira de Souza; Marcelo Mollinari |
| Abstract | |
The importance of sugarcane crop has resulting in a high financial and cientific support. Because, mainly, the genetic complexity of sugarcane genome and the difficult to create new varieties, using traditional breeding methods.The genetic linkage map allow find molecular markers associated with important economic traits, helping to accelerate the breeding process. In this way, molecular markers associated with genetic mapping and QTLs (Quantitative Trait Loci) mapping are important tools to improve the knowledge about the genetic and genomic organization of sugarcane genome. The segregating population of sugarcane consisted of 187 F1 individuals derived from a cross between IACSP95-3018 and IACSP93-3046, this thesis aimed perform a functional genetic mapping and QTLs mapping of economic importance. Thus, yield components evaluated were stalk diameter (SD), stalk weight (SW), stalk height (SH), stalk number (SN), fiber percentage (Fiber), sucrose content (Pol), and soluble solid content (Brix) in two places for three harvest years (2012, 2013 and 2014), adding with two previously collected. The genetic linkage map had a total of 421 markers (SSRs, AFLP and SNPs in single dose) linked, resulting in 118 linkage groups and 16 putative homology groups, with a total length of 4512,6 cM. Using Composite Interval Mapping (CIM), a total of 25 QTL were detected for SD (six QTLs), SW (five QTLs), SH (four QTLs), Fiber (five QTLs), Pol (two QTLs) and Brix (three QTLs). The proportion of phenotypic variation explained by each QTL ranged from 0.069% to 3.87%. Adding this thesis, the development of SNPs (Single Nucleotide Polymorphism) markers was performed, using genes involved in two important metabolic pathways for sugarcane, the C4 Photosynthesis and the Sucrose Metabolism, in total 130 locus SNPs were developed, analyzed and characterized using SuperMASSA software. Ploidy level and allelic dosage were estimated in each SNP loco and a high number of high ploidy level was detected, this result induced to search for evidence for gene duplication on the sugarcane genome, resulting in 80% of studied loci showing duplication regions in at least one relative genome from sugarcane (sorghum, maize or rice). Our results can help sugarcane breeding programs, by SNPs markers identification in genes of economic interesting traits and the QTL mapping for also interesting economic traits (AU) | |