MAPEO DE QTL DE DORMICIÓN EN SORGO GRANÍFERO USANDO UNA POBLACIÓN DE LÍNEAS ENDOCRIADAS RECOMBINANTES

RODRÍGUEZ, MARÍA VERÓNICA; SANTIAGO RENTERÍA ; ARATA GONZALO JOAQUÍN; BENECH-ARNOLD R.L.

Santa Fe

Simposio; IV Simposio Nacional de Sorgo- II Conferencia Internacional de Sorgo 2021. AIANBA.; 2021

AIANBA

Abstract. Pre-harvest sprouting (PHS) can be a serious problem for sorghum production in the central region of Argentina, as grain maturation often takes place during moist and rainy weather. The identification of molecular markers quantitatively associated with dormancy in sorghum will help to improve PHS tolerance. To approach this objective, two sorghum inbred lines with contrasting dormancy (IS9530 and Redlan) were used as parents to obtain a mapping population of RILs. Field trials were conducted for phenotyping germination/dormancy traits on two consecutive years at the experimental field in FAUBA (Bs.As.). A genetic map encompassing 156 SNP markers was built. QTL analysis identified a major dormancy QTL (qDOR-9) in Chromosome 9, explaining 32-40% of variance for germination traits, and close to the Dwarf1 locus. Genotype-By-Sequencing (GBS) analysis showed that the dw1 allele was introduced to Redlan along with a 3.2 Mbp segment from the original donor parent, Dwarf Yellow Milo. The dw1 is not causal for the low dormancy phenotype, as both “Dwarf” and “Standard” Yellow Milos display similar (very low) dormancy. We hypothesize that Yellow Milo background harbors a low dormancy allele linked to Dw1/dw1 locus. Positional cloning using NILs will allow us to narrow the dormancy QTL and separate both traits in breeding programs.