Genetic diversity and relatedness among ornamental purslane (Portulaca L.) accessions unraveled by SRAP markers

Assessment of Genetic Relationships between Streptocarpus x hybridus V. Parents and F1 Progenies Using SRAP Markers and FT-IR Spectroscopy

The genetic relationship among three Streptocarpus parents and twelve F1 hybrids was assessed using sequence-related amplified polymorphism (SRAP) molecular markers and Fourier-transform infrared (FT-IR) spectroscopy. Both methods were able to discriminate F1 hybrids and parents as revealed by cluster analysis. For hybrid identification, the type III SRAP marker was the most effective due to the presence of male-specific bands in the hybrids. Different behaviors in the biochemical variability of DNA samples have been observed by FT-IR spectral analysis, which might be attributed to the inherent nature of the genomic DNA from parents and their F1 progenies. Mantel test was also carried out to compare morphological, SRAP, and FT-IR results based on genetic distances. The highest correlation coefficient was found between morphological and SRAP marker distances (R = 0.607; p ≤ 0.022). A lower correlation was observed between the morphological and FT-IR distance matrix (R = 0.231; p ≤0.008). Moreover, a positive correlation was found between the distances generated with SRAP and FT-IR analyses (R = 0.026) but was not statistically significant. These findings show that both SRAP and FT-IR techniques combined with morphological descriptions can be used effectively for nonconventional breeding programs for Streptocarpus to obtain new and valuable varieties.

Genetic diversity analysis and population structure of some Iranian Fenugreek (Trigonella foenum-graecum L.) landraces using SRAP Markers

Fenugreek is one of the important edible and medicinal vegetables that have a long history of cultivation and consumption. Characterize the extent of the genetic diversity among landraces will provide a good context for future breeding programs and genetic resource preservation. Genetic diversity and population structure of 88 individuals of eight landraces of Iranian fenugreek evaluated based on SRAP markers. Seventy-two bands generated from 6 primers in which 56 (80.11%) band were polymorph. Hamadan landrace showed the lowest values of percentage of polymorphic loci (67.86), Nei's gene diversity index (0.24), number of effective alleles (1.40) and Shannon's Information index (0.36). Nei's genetic distance matrix revealed the highest genetic distance between Hamadan and Yazd (0.203) and the highest genetic similarity between Mahallat and Varamin (0.036) landraces. The most gene flow was between Mahallat and Varamin landraces (Nm=8.36) and the least was between Shiraz and Hamadan landraces (Nm=0.66). An extent admixture of alleles between the Iranian fenugreek landraces was observed by the population structure. Mantel test indicated that the genetic differentiation and gene flow is not associated with geographic distance in Iranian fenugreek landraces. Our observations indicated SRAP is an efficient technique to reveal genetic diversity and population structure of Iranian fenugreek landrace.

Intra-population genetic diversity of Buchloe dactyloides (Nutt.) Engelm (buffalograss) determined using morphological traits and sequence-related amplified polymorphism markers

Genetic variation and diversity are prerequisites for improvement of buffalograss breeding. To assess the within-population genetic diversity of buffalograss, seven morphological traits were evaluated to confirm the variations at the morphological level. The principal component analysis revealed that leaf length, leaf width and stolon branches had a significant contribution to the total variation. The first three principle components showed 72.55% variation. The DNA analysis performed using SRAP primers was used for deducing the diversity at the DNA level. A total of 125 bands were obtained with 8 selected SRAP primer pairs, of which 119 (95.2%) were polymorphic. The polymorphic information content ranged from 0.94 to 0.97 with a mean of 0.96; the marker index ranged from 10.34 to 18.43 with an average value of 14.28. The individuals were successfully assigned to two major groups according to sex in the PCoA and UPGMA dendrogram based on SRAP data, while the individuals could not be grouped based on morphological traits, and the two markers were not significantly correlated (r = 0.0753, P = 0.8489 > 0.05). The molecular data revealed that sex is a critical factor and that female and monoecious plants could be chosen as parents to breed new varieties.