فهرست مطالب پروانه عسگری نیا

safflower species. Iranian Journal of Crop Sciences. 16(3): 165-180. (In Persian). Safflower with high grain oil quality and good tolerance to environmental stresses can be important for oil seed production. A good source of useful genes for improving cultivars of this plant species is its wild relatives. This experiment was conducted to assess the genetic variation and tolerance to drought stress in F3 families derived from a cross between domesticated (Carthamus tinctorius L.) and wild (C.oxyacanthus L.) safflower species using a randomized complete block design with three replications under drought stress and non stress conditions. High heritability was observed for the studied traits including: days to flowering, days to physiological maturity, plant height, number of branches per plant, number of head per plant, number of grain.head, 1000-grain weight and grain yield. The highest genetic coefficient of variability belonged to grain yield per plant 41% and 36% in stress and non-stress conditions, respectively). Transgressive segregation was also observed among the F3 families in both directions and both conditions for most of the traits. The presence of significant genotype by environment interaction for the studied traits implied different reactions of families to drought stress and non-stress conditions. Family 36 with high yield in both stress and non-stress conditions and low reduction in grain yield under drought stress was identified as the superior family. Result of this experiment indicated that there are possibility of improving drought tolerance in safflower genotypes using inter-specific corssing with Carthamus oxyacanthus L.

The selection of high yielding and stress tolerance plant genotypes with the highest water use efficiency and productivity is one of the most important tools for field water management in arid and semi-arid regions. This study was conducted to identify drought tolerant flax families with the highest irrigation water productivity (IWP) among a population of 119 F3 families derived from a cross between KO37 (an Iranian flax cultivar) and SP1066 (a Canadian cultivar) under water stress and non-stress conditions. The mean comparison showed that the segregating population had sufficient diversity for drought tolerance and grain yield. Finally, based on IWP, families no. 38, 39, 72, 74 and 119 that had high IWP in both stress (moderately 0.47 kg/m3) and non-stress (moderately 0.63 kg/m3) conditions, were introduced as the most drought tolerant families. The results of triplot analysis based on STI index and IWP in stress and non-stress conditions introduced the families as the most favorable families. The advanced generations derived from the families can be used in the future breeding programs to improve and produce high yielding-drought tolerant inbred lines in linseed in order to increase water use efficiency and to economize water resources in the field management.

Evaluation of genotypic and phenotypic variation and heritability of important agronomic traits in segregating populations is one of the principles of breeding for quantitative traits. This study was conducted to assess the genotypic and phenotypic variation and drought tolerance in the F3 families derived from a cross between KO37 (Iranian linseed cultivar) and SP1066 (Canadian linseed cultivar) at Research Farm of Isfahan University of Technology, Isfahan, Iran, in 2011 and 2012. Results showed that under drought stress the highest reduction in the number of seed per plant, yield per plant and Irrigation Water Productivity belonged to SP1066 parental genotype. Combined analysis, the highest phenotypic and genotypic coefficients of variability (19% and 25%, respectively) belonged to number of seed per plant, yield per plant and number of capsules per plant. The highest heritability was estimated for 1000-seed weight (86%), plant height (85%) and days to 50% flowering (81%). The presence of high genotypic and continuous variation and also transgressive segregation for studied agronomic traits and IWUE in F3 families under both conditions indicated that the F3 population or its advanced generations can be used in mapping, identification of QTL related to important agronomic traits and increasing drought tolerance in linseed.

This research was conducted to investigate genotyp×environment interaction for grain yield of ten wheat cultivars in 8 environments (combinations of two nitrogen fertilizer treatment and four irrigation regimes). Analysis of additive main effects (analysis of variance) and multiplicative interaction effects (principal component analysis) revealed that the effects of genotype, environment and genotype ×environment interaction were highly significant. three first principal components explained 89% of the interaction sum squares. Biplot of the first principal component and mean grain yields for genotypes and environments revealed that high yielding genotypes of Pishtaz and Moghan1 were more stable cultivars. Pattern analysis of two first significant principal components for genotypes and environments and also cluster analysis based on stability statistics of AMMI3 model (SIPC3 and EV3) showed that Pishtaz genotype had general stability. The grain yield of this cultivar was higher than the average of all genotypes, it was implied that this cultivar had general adaptability. Khazar cultivar was ranked as the second stable cultivar with having grain yield of approximately as much as the average of all genotypes; thus it was considered as a genotype with moderate general adaptability. Cultivars of Alvand, Sabalan, Moghan1, Darab and Falat showed very low stability. Sardary and Omid with lower yield were recognized as unstable cultivars. Also, it was found that all environments had contribution in the interaction effects.

This study was conducted to investigate the genotype¬×¬environment interaction effects on yield and yield components of wheat. Ten cultivars of wheat were evaluated in 8 environments (combinations of two levels of nitrogen and four irrigation regimes) in growing season of 2006-2007 at the Research Farm of Isfahan University of Technology. Based on the stability parameters of Eberhart and Russel, Pishtaz and Moghan1 that had higher yield than the average and regression coefficient of 1 (approximately), were more adapted cultivars. However, Khazar and Alvand cultivars showed specific adaptation to better and Falat, Darab and Roshan cultivars to poor environments. Path analysis of genotype¬×¬environment interaction (Tai's method) showed v1 component that indicated the correlation of fertile panicles/m2 with grain yield, was high and significant only for unstable cultivars, therefore, this component is not a suitable criterion for selection of stability. The environmental components showed that fertility and grain filling periods were the most sensitive growth stages of cultivars to the environmental conditions, therefore, it seems that selection for stability based on this component (v2) may not be effective. Genotypic component of v3 (seed weight) was the most effective component of yield stability and based on this component, Pishtaz was the highest yielding and stable cultivar. In general, according to the results of this study, Pishtaz with grain yields of 9.27 t/ha and with the highest stability was determined as the suitable cultivar.