Evaluation of combining ability morpho-physiological properties of sunflower under optimum and limited irrigation condition

Five CMS lines and four restorer lines (tester) were crossed in a line × tester designe in order to analyze general and specific combining abilities and gene effects in sunflower for some agronomic traits. Hybrids were evaluated in a randomized complete block design, with three replications under optimum and limited water conditions in the Agriculture Research Station, Khoy, during 2014 and 2015 growing seasons. Plant height, head diameter, seeds per head, days to beginning of flowering, days to maturity, proline percent, protein percent, and Chlorophyll b were found to be controlled mainly by dominance effects. CMS lines AGK30 and testers RGHK25 and RGHK50 turned out to be the best general combiners for seed and oil yield. The highest positive and significant GCA for plant height, head diameter, and the number of seeds per head were achieved for RGHK25. The hybrid combination of AGK44 × RGHK56 showed high specific combining ability for seed and oil yield. At grain yield AGK30 line had the highest positive and significant GCA and AGK2 had the highest negative and significant GCA it trait. At evaluation of tester, RGHK50 tester had the highest positive and significant GCA and RGHK56 had the highest negative and significant GCA it trait. At evaluation of specific combining ability RGHK56×AGK44 hybrid had the highest positive and significant SCA and RGHK25× AGK110 hybrid had the highest negative and significant GCA it trait.