Breeding Studies Of Some Economic Characters On Sunflower (helianthus Annuus,l.) :

Mohamed Abdelazeem Salih

The aim of this investigation was to determine the extent ofheterosis and combining ability estimates and their interaction with threespacings (densities) 35000 (Dl) 23333 (D2) and 17500 (D3) plants/fed.in two locations, namely, Sakha (Ll) and EI-Serw (L2), for 50%flowering date, physiological maturity date, plant height, stern diameter,head diameter, lOfl-seed weight, seed husk percent, number ofseeds/head, seed yield/plant, oil percentage, oil yield/plant and seedyield/fed.Six cytoplasmic male sterile (eMS) lines (A-lines), two introducedfrom USDA (AI and A..) and the others produced in El-Serw, Egypt (A3,A6, A9, and AI0), and five fertility restorer lines (RF-lines), three ofthem introduced from USDA (R3, R4 and R8) and two from EI-SerwStation Egypt (R12 and R14) of sunflower were planted at Sakha Agric.Research Station in 1996 summer season for developing 30 top crosses.In 1997 summer season, the thirty hybrids, the five testers, the sixfertile lines (B-lines) and the three hybrids (Eirflor, Malabar and Vidoic)were sown in two locations i.e., Sakha on 3rd July and El-Serw on 17thJune. In each location, a split plot design with three replications was used.The main plots were assigned to plant spacings (densities) while sub-plotswere allocated to forty four genotypes of sunflower. Each sub-plotconsisted of five ridges, each ridge was 420 em. long and 60 em wide.Calcium superphosphate (15.5% P20S) was added during seed bedpreparation at the rate of 1DO-kg/fed. All agricultural practices werecarried out as usual in the convential sunflower fields. Ordinary analysisof variance was performed for the data collected from top crosses in eachlocation to test the significance of all genotypes. Homogeneity of error82· variances was tested for each trait. When differences among top crosseswere significance, line by tester analysis according to Kempthome (1957)was done for each density and over the three densities in each location.Heterosis percentage for seed and oil yield/plant, oil percentage and seedyield/fed was computed for individuals crosses as the percentage increaseof each top cross relative to Eirflor, Malabar and Vidoc commercialsunflower hybrids.Data were recorded on twenty guarded plants chosen at random fromeach sub-plot. The characters studied were:’ 50% flowering date,physiological maturity date, plant height, stem diameter, head diameter,weight of 100 seeds, seed husk percent, no. of seeds/head, seedyield/plant, oil percentage, and seed yield/fed.The results obtained can be summarized as follows:1- The highest mean values for flowering and maturity dates, stemdiameter, head diameter, IOO-seed weight, no. of seeds/head, seedhusk percentage, seed yield/plant and oil yield/plant were obtainedwhen hills were spaced 40 em apart on the ridge. While, plantheight, oil percentage and seed yield/fed were significantly increasedby decreasing spacing between hills from 40 to 20 em.2- The mean squares of interaction between densities (spacing) andlocation were significant for most studied traits. The density (D 1)(20 em between hills) had the highest mean values for oil percentageand seed yield/fed. in EI-Serw followed by D I in Sakha location.3- Genotypes mean squares were significant for all the studied traits atboth locations as well as the combined analysis. Also, significantgenotypes X location mean squares was detected for all traits.4- The top crosses Al x R3, Al x R4, AI, RI2, Al x RI4, A9 x RI2,A9 x R14 and AIO x RI4 showed significant increase in seedyield/fed. compared to the best check hybrids in both locations aswell as the combined analysis.5- The crosses mean squares were significant for all the studied traits inseparate density as well as the combined analysis in both locations.6- The estimates of cr2GCA played the major contribution ininheritance for plant height in separate density as well as thecombined data in both locations, flowering date at D 1 and D2 aswell as the combined data in Sakha location, flowering date at D Iand the combined data in EI-Serw location, stem diameter and headdiameter at DI, D2, D3 and the combined data in Sakha location,and at DI in El-Serw location, IOO-seedweight at the three densitiesand the combined analysis in El-Serw location and at D 1 in Sakhalocation, seed yield/plant at D2 and D3 in El-Serw location and seedyield/fed. at D3 in El-Serw location.7- The parental inbred lines Al and A6 and the parental testers RI2 andRI4 gave significantly positive gAi effect for seed yield.8~ The top cross A1 x R3 in both locations and top cross A6 x R8 in thesecond location (El-Serw) expressed significantly positive Sij effectsfor seed yield/plant and yield kg/fed.9- For seed yield/fed., thirteen, five and eitht top crosses in Sakhalocation, seven, six and fourteen crosses in El-Serw location showedsignificant positive heterotic effects relative to Eirtlor, Malabar andVidoic, respectively. The four top crosses (AI x R3), (AI x R4), (AIx R12) and (A9 x RI4) outyielded the check hybrids in bothlocations. The heterotic effect over two locations of the three checkhybrids ranged from 11.6% for (AI x R4) to 21.82% for (AI x R3).It could be concluded that these crosses may be useful for improvingseed yield of sunflower.