Seed dormancy QTL identification across a Sorghum bicolor segregating population

RENATA CANTORO; M. VERÓNICA RODRIGUEZ; LUIS FERNÁNDEZ; RUTH HEINZ; JORGE GIECO; ROBERTO LUIS BENECH ARNOLD; GERARDO CERVIGNI; NORMA PANIEGO

EUPHYTICA

SPRINGER

Lugar: Berlin; Año: 2016 vol. 221 p. 41 - 56

0014-2336

Pre-harvest sprouting (PHS) in Sorghumbicolor is one of the main constrains for its productionin the central region of Argentina, as grain maturationoften coincides with rainy or high environmentalhumidity conditions. The obtention of more dormantgenotypes with higher PHS resistance has always beena desirable trait for breeders but the typical quantitativenature of seed dormancy makes its manipulationdifficult through classical breeding. Dissecting thisquantitative variability into quantitative trait loci(QTL) is a main concern especially in cereal species.In this work, a sorghum segregating populationincluding 190 families was genotyped withmicrosatellite markers and the SbABI5 candidategene. A genetic map encompassing 96 markers and atotal length of 1331 cM was built. Seed dormancy wasphenotyped in F3 and F4 panicles in two contrastingArgentinean environments (Castelar and Manfredi).Six seed dormancy QTL for mature grains wereidentified (qGI-1, qGI-3, qGI-4, qGI-6, qGI-7 andqGI-9) with the aid of QTL Cartographer andQTLNetwork, three of them (qGI-3, qGI-7 and qGI-9) being co-localised by both approaches. No epistasiswas detected for the identified QTL but QTL-byenvironmentinteraction was significant for qGI-7 andqGI-9. Interestingly, seed dormancy candidate genes