Identification of QTLs for grain yield and some agro-morphologicaltraits in sunflower (Helianthus annuus L.) using SSR and SNP markers

Many agriculturally important traits are complex, affected by many genes and the environment.Quantitative trait loci (QTL) mapping is a key tool for studying the genetic structure of complex traits inplants. In the present study QTLs associated with yield and agronomical traits such as leaf number, leaflength, leaf width, plant height, stem and head diameter were identified by using 70 recombinant inbredlines (RILs) from the cross (♀) PAC2 × RHA266(♂). RILs and their parents were evaluated in arectangular 89 lattice design with two replications. High genetic variability and transgressivesegregation were observed in all studied traits. Genetic gain representing the difference between 10% ofselected RILs and their parents was significant for most of the studied traits. Positive and significantgenotypic and phenotypic correlations were observed among the studied traits. QTL analysis wasperformed using a recently developed SSR and SNP sunflower linkage map. The map consists of 210SSRs and 11 SNP markers placed in 17 linkage groups (LGs). The total map length is 1,653.1 cM with amean density of 1 marker per 7.44 cM. Composite interval mapping (CIM) procedure detected 21 QTLsinvolved in genetic control of studied traits. The phenotypic variance explained by the identified QTLsvaried from 1.13 to 73.70%. QTLs such as HMBPP associated with the expression of more than one traitcould increase the efficiency of marker-assisted selection (MAS) and genetic progress in sunflower.

Identification of QTLs for grain yield and some agro-morphologicaltraits in sunflower (Helianthus annuus L.) using SSR and SNP markers Keywords:

Genetic variation , linkage map , molecular markers , QTL mapping , sunflower , yield-relatedtraits