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Mapeamento de QTLs para tolerância ao frio e características de importância agronômica em arroz
| Content Provider | Semantic Scholar |
|---|---|
| Author | Serafim, Danielle Costenaro Da Silva |
| Copyright Year | 2003 |
| Abstract | Low temperature is a common stress for the rice crop in temperate regions, so cold tolerance is a highly desirable trait in Brazilian rice genotypes cultivated in the Southern region, where chilling temperatures affect crop establishment and lower grain yield. Molecular mapping is a promising strategy for the study and comprehension of traits with a complex genetic control, such as rice cold tolerance. Based on this, the aims of this work were to study the inheritance and heritability of the cold tolerance traits and of the agronomic traits to be mapped, to develop a molecular map from a F2 segregant population of the cross IRGA 417 (Indica) X Quilla 66304 (Japonica) and to identify quantitative trait loci (QTLs) for cold tolerance at the germination and vegetative periods and for agronomic traits that differentiate these two subspecies. Finally, to investigate the possibility of obtaining recombinant individuals with desirable agronomic characters and cold tolerance in the F2 population of the cross IRGA 417 x Quilla 66304. Analyses of the frequency distributions of the F2 generation evidenced the difficulties in estimating the number of genes that control the evaluated traits, and all of them showed continuous distribution and transgressive segregation in relation to the parents. The map was constructed based on eight SSR markers and 42 AFLP markers with an average density of one marker every 38.8 cM and a total length of 581.6 cM. Five QTLs were identified, one of them is related with cold tolerance at the germination period, and explains 15.9% of the phenotypic variation of this trait. The other four QTLs identified were related with grain width (21.3%), spikelet sterility (61.6%), plant height (34.5%) and grain length (21.9%). The detection of one QTL associated with cold tolerance at the germination period and of four other QTLs associated with the agronomic traits in the IRGA 417 x Quilla 66304 population demonstrates the feasibility of this type of analysis. However, an enriched linkage map is needed to allow detection of other QTLs associated with the studied traits. Recombinant plants with high coleoptile regrowth and other desirable agronomic traits were found, indicating that the population obtained from IRGA 417 x Quilla 66304 has potential for cold tolerance rice breeding of genotypes adapted to the Soluthern region of Brazil. 1 Master of Science Dissertation in Agronomy, Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. (68p.) May, 2003. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://www.lume.ufrgs.br/bitstream/handle/10183/3667/000391068.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
