Modares Journal of Biotechnology

Abstract One of the newest methods in plant breeding programs is mapping quantitative trait loci (QTL) with molecular markers. In order to identify QTL associated with some chemical traits such as chlorine, nicotine, sugar concentrations and ash in oriental tobacco, a population of 55 recombinant inbred lines coming from the cross Basma seres 31 × SPT406 were evaluated for above mentioned traits. QTL mapping was performed using linkage map developed on 103 recombinant inbred lines by 64 molecular markers including 14 SSR, 24 ISSR and 26 retrotransposone. The linkage map is composed of 7 linkage groups (LGs). Composite interval mapping revealed 5 QTLs associated with studied traits. Phenotypic variation explained by identified QTLs varied between 0.34 and 0.70. Any QTL was not detected for sugar concentration in tobacco leaves. Common markers between some of studied traits can be due to linkage or pleiotropic effects. The common markers lead to increase the efficiency of marker-assisted selection in plant breeding programs via simultaneously selection for several traits.

Abstract Drought is known as an important factor limiting growth and product of field crops in most parts of the world and Iran. In the present work, the genetic diversity of 100 inbred lines of sunflower was investigated based on agro-morphogical characters with simple lattic design with two replications under normal and drought stress conditions. Combined analysis of variance revealed significant differences among lines for most of studied traits. Uneder normal condition, the highest coefficient of genetic variation was observed for stem diameter and the lowest one observed for relative water content. In drought stress condition, the highest coefficient of genetic variation was observed for seed yield per plant and the lowest one observed for days to flowering. The results of correlation analysis showed that there is significant and positive correlation between seed yield per plant with most of the studied traits in both stress conditions. Stepwise regression analysis revealed that under drought stress condition 73.9 percent of seed yield per plant variation was expailed by heed diameter, leaf width and petiol length and in normal condition 73.6 yield grain per plant variation explained by head diameter and plant height. Cluster analysis grouped lines into 4 clusters in each one of normal and drought conditions but the distruption of lines within groups were differents depending to stress environment that present the genetic variability for drought tolerance in sunflower lines.

Abstract This study was designed to investigate the genetic diversity and relationships between yield and related traits in oily sunflower lines. 152 sunflower lines collected from different parts of the world were investigated at completely randomized design with nine replications on Urmia University in 1391 under pot conditions. 14 agro-morphological traits including plant height, stem diameter, number of leaves, leaf length, leaf width, petiole length, head diameter, 100 seed weight, head dry weight, , seed yield per plant, number of days from planting to flowering, and number of days from planting to maturity, dehulled kernel to whole kernel and harvest index were measured. Analysis of variance revealed significant differences among genotypes for all studied traits. Among the traits, the highest coefficient of phenotypic variation was observed for seed yield per plant (56.30), harvest index (44.4) and head dry weight (35.44). The results of correlation analysis showed that there is significant and positive correlation between seed yield per plant with most of the studied traits. Results of sequential path analysis revealed that the variables such as number of leaves, dehulled kernel to whole kernel, head diameter, and plant height were arranged as the first-order variables. Cluster analysis subdivided the genotypes into 4 groups. The maximum distance were observed between the genotype from groups 3 and 4 (28.30).

Abstract This study was conducted to evaluate genetic variation among 70 sunflower recombinant inbred lines (RIL) derived from the crosses PAC2 × RHA266 together with parents based on seed morphological traits by using a rectangular lattice design with two replications. Seed morphological such as kernel length, kernel width, kernel diameter, 100-kernel weight, percentage of hull, percentage of dehulled kernel and seed yield per plant was measured. Analysis of variance revealed significant differences among lines for the studied traits. The highest coefficient of phenotypic variation was observed for seed yield per plant (23.42) and the lowest one was observed for percentage of dehulled kernel (1.37). The highest heritability was observed for 100-kernel weight (0.995) and kernel width (0.990) and the lowest one was observed for the yield per plant (0.521). The highest correlation coefficients were observed between kernel diameter and kernel width (0.908). Principal component analysis reduced the seed characteristics traits to 2 components explaining 81% accumulative variance. By using Ward clustering method based on seed morphological traits the 72 studied sunflower lines were classified into six groups.