J. ENCHEVA, G. GEORGIEV and E. PENCHEV
Dobroudja Agricultural Institute, BG – 9520 General Toshevo, Bulgaria
ENCHEVA, J., G. GEORGIEV and E. PENCHEV, 2015. Heterosis effects for agronomically important traits in sunflower (Helianthus annuus l.). Bulg. J. Agric. Sci., 21: 336–341
Hybrid combination concluded Bulgarian male sterile line cms807 and mutant fertility restorer line 278 R. Father line was developed by treatment of immature zygotic embryo of restorer line 381 R with ultra sonic. Hybrid developed with the participation of line 278 R considerably exceeded the mean standard (the Bulgarian commercial hybrid San Luka and French commercial hybrid LG-5635) by seed and oil yield. Seed yield of hybrid combination was significantly higher in comparison to mean standard San Luka and LG-5635 with 71 kg/da, or 19.1%, and oil yield with 59 kg/da, or 141.8%. In our study 4 of 8 characters recorded positive and significant heterosis in the direction of both relative to parental average (h1) and relative to better parent (h2). In h1 the variation was from 120. 2% to 212.7%; in h2 the variation was within 111.9% to 132.9%. Highest magnitude of heterosis was observed at seed yield per plant in comparison to parental mean, followed by head diameter in comparison to better parent. Lack of heterotic effect was established for traits 1000 seed-weight, seed length, seed width and seed thickness in relation of parental mean and to better parent. At the base of calculated coefficients it can be concluded a dominant model of inheritance of the studded traits such as plan height, diameter of head, total seed number per head and seed yield per plant, in the direction of parental mean and to better parent. Instead higher seed and oil yield new hybrid combination simultaneously possessing high resistance to the Orobanche population of races-A-G distributed in Bulgaria and immunity to Plasmopara helianthi-races 300, 700 and 731.