Nine genetically diverse sunflower promising lines in their economic trait were crossed using line by tester mating design in 2018 spring season, to estimate per se performance, combining ability, heterosis, gene action and heritability for earliness, yield and its attributes traits. The parents involved four sunflower CMS lines namely L1 (A3), L2 (A5), L3 (A9) and L4 (A13) (called hereafter "Lines" (as female parents) and five sunflower genotypes T1 (RF9), T2 (RF10), T3 (RF11), T4 (RF14) and T5 (RF1) as male parents (called hereafter "Tester"). In 2018 and 2019 summer season, the nine parents along with their 20 F 1 s seeds were evaluated at Shandaweel Agricultural Research Station, ARC, Sohag Governorate, Egypt using a randomized complete blocks design with three replications. Mean squares due to parents (P), crosses (C), CMS lines (L), RF testers (T), P vs C and L x T were significant for all studied traits. A larger magnitude of non-additive gene action than additive was revealed by greater ratios (GCA/ SCA) than unity for all studied traits (except for days to 50% flowering). A5 and A13 of CMS lines and RF11 and RF14 of RF lines proved to be the best general combiners for seed weight plant -1 and one or more of its attributes traits. Moreover, the best cross combinations A13 x RF11, A13 x RF1 and A5 x RF9 performed better than other developed hybrids in view of seed weight plant -1 and one or more of its attributes, hence these F1 hybrids could further be used on commercial exploitation. For citation:Ahmed MA, Abdelsatar MA, Attia MA, Abeer AA. GGE biplot analysis of Line by tester for seed yield and its attributes in sunflower.

The present investigation was carried out during 2010 and 2011 seasons to study the effects of inbreeding depression in sunflower. In 2010 season, Giza102 an open-pollinated cultivar of sunflower was planted at Shandaweel Agric. Res. Stn., ARC. 100 plants were selected and selfed. After harvest, 23 S 1 lines which produced enough seed were chosen for evaluation in the next season. In 2011 season, 23 S 1 lines and Giza102 were evaluated in Randomized Complete Block Design (RCBD) experiment with three replicates. Data were recorded on days to 50% flowering, days to maturity, plant height, stalk diameter, head diameter, 100-achene weight, achene yield/plant, achene yield/plot and oil content. Analysis of variance revealed highly significant differences among S 1 lines for all studied traits. Broad sense heritability showed high estimates for all the studied traits. Phenotypic coefficient of variability (P.C.V) for various traits were relatively higher than genotypic coefficient of variability (G.C.V) for the S 1 per se. Oil content was negatively and not significant correlated with head diameter, 100-achene weight, achene yield/plant and achene yield/plot. Achene yield/plot was positively and significant correlated with head diameter, 100-achene weight and yield/plant. The reduction of yield/plot of the S 1 lines was 2.68% of the base pop. Achene yield/plot of 10 S 1 lines per se were significantly or highly significantly fewer than the base pop. Giza102, while 8 S 1 lines per se exceeded significantly or highly significant than the base pop. Giza102. The decrease in oil content due to inbreeding was 2.25%. Most of the S 1 lines were less than the base population. The best ten S 1 lines per se were Nos.1, 7, 11, 14, 15, 16, 17, 18, 20 and 21, which gave the higher oil content and some other desirable character were selected and used as parents to produce the first cycle selection.

Simultaneously identify superior performing in terms of seed yield and seed oil content and broad adaptation across a wide range of different environments is an important target for sunflower breeder. So, 10 sunflower genotypes were evaluated across the eight various environments created by sowing at four locations i. e. Kafr El Hamam/ Sharkia, Shandaweel /Sohag, Tag El Ezz/ Dakahlia and Al Arish/ North Sinai Agricultural Research Stations, Agricultural Research Center (ARC), Egypt during the two successive summer seasons 2018 and 2019 using randomized complete block designs with four replications in each environment. Results showed that mean squares due to environments, genotypes and their interaction were highly significant for seed yield and seed oil content. Most stability approaches revealed that high performing stable genotypes were L240 for seed yield and Sakha 53, L110 and L235 for seed oil content under divergent environments. Hence, these four stable sunflower genotypes could be behaved as good breeding materials stock for sunflower improvement.

Aims: This study was conducted to investigate the nature of genotypes-environments interaction (GEI) and identify the most stable sunflower hybrids that can give high seed yield with high oil yield under a wide range of environmental conditions in Egypt. Place and Duration of Study: Fifteen hybrids were evaluated across three years (2017 to 2019) and three locations (Giza, Ettay El-Barod and Shandaweel). Study Design: The experiments were laid out in Randomized Complete Block Design (RCBD) with three replications. Methodology: Analysis of variance, some stability methods as additive main effects and multiplicative interaction (AMMI) and genotype main effects and genotype-by-environment interaction effects (GGE-biplot) were conducted. Results of stability indices were ranked as AMMI Stability Value (ASV), yield stability (YSI) and rank-sum (RSI) and heritability was estimated. Results: Combined analysis revealed that GEI was highly significant, indicating the possibility of selection for stable ones. AMMI analysis confirmed that the seed yield performance of sunflower hybrids was largely influenced by the environment. On the contrary, environments recorded less impact on oil yield as compared to the effect of hybrids (genetics). Then, heritability estimate of oil yield trait (93.86%) was higher than the seed yield one (31.10%). Indices of YSI and RSI presented that hybrids (H15, H7 and H11) and (H7, H8 and H15) were the best stable promising ones in seed and oil yield, respectively. GGE-biplot analysis indicated that hybrids (H15, H7, H4 and H11) and (H7, H15, H8 and H15) were considered as the most ideal for seed and oil yield, respectively whereas Shandweel was the ideal environment for both. Conclusion: Therefore, all analyses agreed on hybrids H15, H7 and H11 were considered as the most desirable and stable ones. These hybrids can be recommended for wider cultivation due to better seed and oil yield with stable performance across the test environments.

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