RESUMO
In this study, we analyzed the behavior of several neglected, ancestral, and domesticated wheat genotypes, including Ae. triuncialis, Ae. neglecta, Ae. caudata, Ae. umbellulata, Ae. tauschii, Ae. speltoides, T. boeoticum, T. urartu, T. durum, and T. aestivum under control and salinity stress to assess the mechanisms involved in salinity tolerance. Physiological and biochemical traits including root/shoot biomasses, root/shoot ion concentrations, activity of antioxidant enzymes APX, SOD, and GXP, and the relative expression of TaHKT1;5, TaSOS1, APX, GXP, and MnSOD genes were measured. Analysis of variance (ANOVA) revealed significant effects of the salinity treatments and genotypes for all evaluated traits. Salinity stress (350 mM NaCl) significantly decreased root/shoot biomasses, K+ concentration in root/shoot, and root/shoot K+/Na+ ratios. In contrast, salinity stress significantly increased Na+ concentration in root and shoot, activity of antioxidant enzymes (APX, SOD, and GPX) and relative expression of salt tolerance-related genes (TaHKT1;5, TaSOS1, APX, GPX, and MnSOD). Based on heat map and principal component analysis, the relationships among physiological traits and relative expression of salt-responsive genes were investigated. Remarkably, we observed a significant association between the relative expression of TaHKT1;5 with root K+ concentration and K+/Na+ ratio and with TaSOS1. Taken together, our study revealed that two neglected (Ae. triuncialis) and ancestral (Ae. tauschii) wheat genotypes responded better to salinity stress than other genotypes. Further molecular tasks are therefore essential to specify the pathways linked with salinity tolerance in these genotypes.
RESUMO
To detect the genetic variation and relationships among different Salvia ecotypes/species, the gene targeted CAAT box derived polymorphism (CBDP) markers were employed in terms of their efficiency. In this study, 25 CBDP primers amplified a total of 323 different polymorphic fragments that discriminate all 26 Salvia ecotypes/species and produced an informative and differentiated dendrogram and population structure. The CBDP markers were found to be effective in Salvia genetic diversity estimation with regard to the averages polymorphism (100%), polymorphism information content (PIC = 0.89), marker index (MI = 4.5) and the effective multiplex ratio (EMR = 5.01) which were higher than other reported markers on Salvia. The extent of heterozygosity (0.034≤H≤0.223) and Shannon index (0.042≤I≤0.278) indicated a high level of genetic variation among Salvia species. The species containing the highest basic chromosome number (X = 12) revealed the highest values for the number of different (Na) and effective (N e) alleles, Shannon index (I), and heterozygosity (H). Additionally, the tetraploid species showed high values of N a, Ne, I and H compared to the diploid species. Mean of gene differentiation (Gst) among Salvia species was 0.792, and the estimation of gene flow (Nm) was 0.13, indicating high genetic differentiation. Remarkably, similar results were obtained from the principal co-ordinate analysis (PCoA) as compared with the cluster analysis, in which all different Salvia species formed individual groups. In conclusion, because the CBDP markers are derived from the gene containing regions of the genome, consequently, the high genetic diversity among studied Salvia species would be more useful for crop improvement programmes, such as hybridization between species and QTL mapping. The potential of CBDPs for analysing the phylogeny and genetic diversity of Salvia species is another key result with practical implications.