S. S. Pourdad, M. Jamshid Moghaddam,
Volume 2, Issue 6 (3-2013)
Abstract
GGE (genotype + genotype×environment) biplot is one of the new graphical methods to study genotype×environment interaction in which the effects of genotype and G×E interaction are not separated and selection is based on both of these effects. In the present research, GGE biplot was used to study 14 safflower genotypes over six research stations under water stress and non-stress conditions in spring planting. The results of analysis of variance showed that 93.9% of total variation was due to environment and 6.1% due to genotype and G×E interaction. The polygon-view of GGE biplot recognized six superior genotypes and four mega-environments. The best genotypes within each environment were determined. The seven genotypes located in sectors that no environment was placed indicated that these genotypes were poor in most of the environments. Simultaneous evaluation of yield and stability through average environment coordinate biplot showed that Hartman, Gila and Sina with high seed yield had higher yield stability. Hartman was the nearest variety to ideal genotype (assumed genotype with the highest yield and stability) and Gila and Sina varieties were also close to ideal genotype, too. Biplot of correlation among environments revealed that Shirvan and Kohdasht were similar environments, so that water stress and non-stress conditions were not able to make differences between these locations. Zanjan, Ghamlo, Kohdasht and Sararood environments under non-stress conditions had higher discriminating ability.
M. Jamshid Moghaddam, S. S. Pourdad,
Volume 10, Issue 2 (summer 2006)
Abstract
To evaluate seed germination and seedling growth of safflower in moisture stress, germination of 15 genotypes at four water potential levels (ψ: 0, -0.4, -0.8 and –1.2 Mpa) was tested by Polyethylene glycol (PEG6000). Maximum germination (Gmax), germination rate index (GRI), time length to reach 50% germination (T50), rootlet length (RL) and shootlet length (SL) were investigated. Effects of water potential levels and genotypes were significant for all the characteristics studied. Minimum water potential for germination was estimated between –1.17 and –1.59 Mpa in Goshkhani and LRV-51-51 genotypes, respectively. Different responses to moisture stress were found for rootlet length. In lower potential levels, seedlings had longer, weaker and thiner rootlets in comparison to the zero water potential (control). An increase in stress to –1.2 Mpa led to a severe reduction in rootlet elongation. All stress levels decreased GRI and SL, while potentials lower than –0.4 Mpa decreased Gmax. With a decrease in water potential from 0 to –0.8 Mpa, the T50�stage was delayed three-fold compared to the control. Exotic genotypes had longer T50 stage than Iranian genotypes. The highest GRI was related to three Iranian genotypes LRV-51-51, Varamin 295, and Isfahan local, and the lowest was related to CW-74 exotic genotype. Some of genotypes were evaluated for seed yield, oil yield and seed oil percentage under rainfed condition in 2004-05. The highest oil yield average belonged to two exotic genotypes PI- 537598 and Lesaf (326.4 and 313.9 Kg/ha, respectively) and the least was related to Zarqhan 279 Iranian genotype (133.2 Kg/ha). Negative and significant correlation was observed between seed oil percentage and GRI in the 0, -0.8 Mpa potential levels. According to the results, the existing genetic variation for germination parameters can be used for genetic improvement of seed early vigor in safflower.
