Identification of QTLs for germination and seedling development in sunflower (Helianthus annuus L.)

A population of recombinant inbred lines (RILs) developed through single-seed descent from the cross between 'PAC-2' and 'RHA-266' were used in this study. RILs and their two parents were screened with AFLP and SSR markers and a linkage map was constructed based on 367 markers. Several QTLs associated with: time to 50% germination, percentage of germinated seeds, shoot and root length, shoot and root fresh weight, shoot and root dry weight and percentage of normal seedlings were identified. The effects of each QTL are moderate, ranging from 6 to 33%, but a high percentage of phenotypic variance is explained when considering all the covariantes (TR2 ranging from 47 to 82%). QTLs controlling some of the traits are on the same linkage group and sometimes close together. Genetic correlations between the traits also confirm these relations. Although the detected regions need to be mapped more precisely, the information obtained should help in marker-assisted selection.