Estimation of Genetic Variance Components and Heritability of Sunflower Single Cross Hybrids Using North Carolina Design I

To estimate genetic parameters in sunflower single cross hybrids، a North Carolina Design I experiment was conducted in a randomized complete block design with three replications at Agricultural and Natural Resources Research Station of Khoy. In 2005، six fertility restorer male lines were crossed with 18 cytoplasmic male sterile female lines. Each male line was crossed with three different female lines to make two sets with nine hybrids in each set. In 2006، Single cross F1 hybrids were planted to estimate genetic parameters. Data were collected from agronomic traits including: flowering initiation، seed filling period، maturity، plant height، stem diameter، head diameter، 1000 seed weight، seed numbers per head، seed/achen ratio، biological yield، harvest index، oil content، seed yield and oil yield. Survey results showed that gene action in some loci for 1000 seed weight and seed numbers per head were partial dominant (a < 1)، for oil yield were complete dominant (a =1) and for other traits were over dominant (a > 1). To improve seed filling period and harvest index traits، use of selection methods is sufficient. Traits such as plant height، stem diameter and head diameter، hybridization method use to improve them is unavoidable. For important traits such as seed yield، oil yield and biological yield، using both selection and hybridization methods is recommended.