Phylogenetic relationship and sequence diversity of candidate genes involved in anthocyanin biosynthesis pathway in Carthamus species with contrasting seed coat colors.

The morphological structure of seed such as coat color can be considered as effective parameters in the evaluation of resistance to pests. The present study is aimed at achieving these goals: first, to determine the phylogenetic relationship of different species of safflower with different seed coat colors based on three candidate genes in the anthocyanin biosynthesis pathway that encode the early steps (PAL: phenylalanine ammonia-lyase and CHS: chalcone synthase) and the final step (UFGT: flavonoid-3-O-glucosyltransferase); second, based on our previous study on the absence of cyanidin-3-O-glucoside (Cyd-3-glu) in white/brown-seeded genotypes, it can be determined whether the lack of production is related to the absence of genes or the lack of expression. In general, the detection of Cyd-3-glu upstream compounds in all studied safflower genotypes, regardless of the color of the seed coat, can be interpreted as the expression of genes responsible for the synthesis of these compounds in the anthocyanin synthesis pathway. In addition, these findings indicated that the accumulation pattern of the mentioned secondary metabolites could be varied in safflower genotypes according to the seed coat color pattern. Regarding the UFGT gene, the evidence showed that this gene is expressed in safflower genotypes with two different seed coat color patterns, but in each genotype the tendency to produce secondary metabolites is different. Consequently, it seems that UFGT may not only regulate Cyd-3-glu biosynthesis but also involved in biosynthesis of flavonol glucoside in black safflower. Additionally, UFGT only affected flavonol glycosides biosynthesis and had no effect on Cyd-3-glu biosynthesis in white- seeded safflower genotypes.

Drought adaptability of different subspecies of tetraploid wheat (Triticum turgidum) under contrasting moisture conditions: Association with solvent retention capacity and quality-related traits.

Few prior efforts have been made to investigate the genetic potential of different subspecies of Triticum turgidum for drought tolerance and their quality-related traits compared with common wheat (Triticum aestivum) and to identify the association among agronomic, micronutrients, and quality-related traits, especially under climate change conditions. In this research, grain quality, technological properties of flour, and some agronomic traits were studied in 33 wheat genotypes from six different subspecies of Triticum turgidum along with three cultivars of Triticum aestivum in the field, applying a well-watering (WW) and a water stress (WS) environment during two growing seasons. A high degree of variation was observed among genotypes for all evaluated traits, demonstrating that selection for these traits would be successful. Consequences of water stress were manifested as declined DM, GY, and LASRC; and significantly increased GPC, K+/Na+, WAF, WSRC, SuSRC, and SCSRC compared to the well-watering condition. The reductions in the unextractable polymeric protein fraction and glutenin-to-gliadin ratio indicated a poorer grain yield quality, despite higher protein content. This study showed that the early-maturing genotypes had higher water absorption and pentosan, and therefore were more suitable for bread baking. In contrast, late-maturing genotypes are ideal for cookie and cracker production. Two subspecies of T. turgidum ssp. durum and T. turgidum ssp. dicoccum with high micronutrient densities and quality-related traits, and T. turgidum ssp. oriental due to having high values of grain protein content can be used to improve the quality of T. aestivum through cross-breeding programs. Based on the association of different traits with SRC values and other quality-related traits and PCA results, contrasting genotypes can be used to develop mapping populations for genome studies of grain quality and functional properties of flour in future studies.

The influence of altered sink-source balance on the plant growth and yield of greenhouse tomato.

This experiment aimed to investigate the status of tomato plants in terms of sink or source-limitation of 2 cultivars of greenhouse tomato (Solanum lycopersicum L.), i.e., 'Grandella' and 'Isabella' under the greenhouse conditions of Iran and to improve the yield and plant growth by manipulating the sink-source balance. To this end, 4 treatments were applied: leaves were not pruned and fruits were pruned to one per truss (1F/3L), leaves were not pruned and fruits were pruned to two per truss (2F/3L), leaves were not pruned and fruits were pruned to three per truss (3F/3L) and no leaf and fruit pruning (control). The results showed that truss pruning reduced the sink demand and consequently, increased the amount of available assimilate for the growth of the remaining fruits or vegetative parts. The negative correlation between the leaf area index and the net assimilation rate and no significant difference in the net assimilation rate between different sink/source ratios showed that the excess leaf area index does not contribute in increasing the  assimilate production and hence, total yield. Total fruit weight, harvest index, and the ratio of the ripe fruits to the total fruit led to the highest yield for control plants. No changes in chlorophyll, protein content and nitrate reductase activity were the evidence for the fact that sink/source ratio  do not affect light-harvesting and light-utilizing components of photosynthesis. Since the individual weight of fruits increased with decreasing fruit number per trusses, the growth of individual fruits in both cultivars was source-limited and truss pruning can decrease this limitation. Future studies should be carried out to determine the best level of sink/source ratio that in addition to producing an acceptable amount of yield, meets the needs of consumers in the current stressful world by increasing the antioxidant and nutriceutical content of fruits.

Genetic relations among and within wild and cultivated Thymus species based on morphological and molecular markers.

In the present study, the diversity of 11 Thymus species was assessed using molecular and morphological markers. Essential oil content and morphological traits were also investigated during two agronomic years. The result of the analysis of variance showed considerable differences among morphological traits. In the first and second years, the essential oil content of the species varied from 0.63 to 1.94% and 0.86 to 2.34%, respectively. T. vulgaris and T. migricus showed the highest essential oil content in two agronomic years. In this research, nine ISSR primers were also used to amplify 151 polymorphic bands in 77 accessions belonging to 11 Thymus species. Cluster and principal component (PCA) analyses classified the species in three major groups. Among the species, T. vulgaris and T. fedtschenkoi presented relatively higher genetic distance in comparison with other species. Analysis of molecular variance (AMOVA) revealed that 72.34% of the total variation was belonged to within-species variation, while 27.66% was associated among the species. High gene flow (Nm = 1.11) and genetic differentiation (Gst = 0.31) were also observed among the species. T. transcaspicus exhibited the highest genetic variation (0.19), polymorphism % (57.69%), and Shannon index (0.29). The STRUCTURE analysis also showed a high admixture of Thymus species that might be originated from a high rate of natural hybridization. Finally, based on molecular and morphological information, T. vulgaris and T. carmanicus can be suggested as good candidate species for further breeding programs in Thymus species.

Essential Oil and Bioactive Compounds Variation in Myrtle (Myrtus communis L.) as Affected by Seasonal Variation and Salt Stress.

The effect of different NaCl concentrations (control, 2, 4 and 6 dS/m) and three harvesting times in different seasons including spring (9 April), summer (5 July), and fall (23 September) was evaluated on essential oil (EO) yield, composition, phenolic, flavonoid content, and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4 dS/m) and spring season. The main constituents obtained from gas chromatography/mass spectrometry analysis were α-pinene, 1,8-cineole, limonene, linalool, α-terpineol, and linalyl acetate in which α-pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2 dS/m) and spring, while 1,8-cineole varied from 7.42% in high salinity (6 dS/m) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content, and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and ß-carotene/linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC50 values obtained in 6 dS/m in spring (375.23 µg/ml) followed by summer (249.41 µg/ml) and fall (618.38 µg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using high performance liquid chromatography analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major EO components, while it can improve the amount of phenolic acids.

Variation in Essential Oil Yield and Composition of Dorema aucheri Boiss., an Endemic Medicinal Plant Collected from Wild Populations in Natural Habitats.

In the present research, variability in essential oil (EO) composition of five Dorema aucheri populations collected from natural habitats in different regions of Iran, were investigated. The EO content of populations varied from 0.28 to 0.68%. According to gas chromatography/mass spectrometry analysis, ß-caryophyllene (7.17 - 35.73%), thymol (23.45 - 29.64%), ß-gurjunene (2.58 - 5.89%), carvacrol (1.32 - 2.67%) and cuparene (1.97 - 2.98%) were the major components. Hierarchical cluster, principal component and canonical correspondence analyses classified the studied populations into three groups based on major EO components. The environmental parameters of the collected sites were also evaluated. According to the results, it might be suggested that sandy soils with high mean annual precipitation were major environmental factors influencing the amount of ß-caryophyllene, while thymol, cuparene and caryophyllen oxide increased in silty and clay soils. Finally, the population collected in high altitudes and clay soils had higher amount of ß-gurjunene.