QTLs identification for characteristics of the root system in upland rice through DNA microarray

Identificação de QTL para características do sistema radicular em arroz de terras altas por meio de microarray

ABSTRACT.

The aim of this work is the construction of a genetic map and identification of quantitative trait loci (QTLs) that control characteristics of the root system of rice. We evaluated a F_2:3 population composed of 150 families from the cross between the varieties IAC 165 × BRS Primavera. Genotyping was performed in the F₂ population using 3,742 SNP (Single Nucleotide Polymorphism) markers. The evaluation of the root system in the F₃ population was performed through a large-scale phenotyping method based on image generation with a CI-600 root scanner and on quantification through the WinRhizo^(r) software. The experiment was arranged in a randomized block design with three replications performed under greenhouse. The variables analyzed were root length, root surface area and root volume at the depths of 5 to 25 cm and 25 to 45 cm. The SNP markers analysis allowed the construction of the genetic map with a full length of 1424 cM. The linkage group with the largest coverage area was number 3 with 270 cM (100 SNPs), followed by linkage group 1 with 249 cM (170 SNPs) and linkage group 2 with 163 cM (99 SNPs). The genetic analysis allowed the detection of QTLs for all the characteristics.

Keywords:
genomic; Oryza sativa L.; DNA chip; QTL mapping; abiotic stress