Morphological, genetic and epigenetic aspects of homoploid hybridization between Salvia officinalis L. and Salvia fruticosa Mill.

Abstract

The inheritance of phenotypic, genetic and epigenetic traits in hybridization events is difficult to predict, as numerous evolutionary, ecological, and genetic factors can play a crucial role in the process of hybridization. In the middle Adriatic island of Vis, we investigated hybridization between Salvia officinalis and S . fruticosa at morphological, genetic and epigenetic levels. SSR results revealed that hybrid individuals were characterized by diploid set of chromosomes suggesting homoploid hybridization. A well-defined group that mostly comprised of F 1 generation individuals was detected. For the majority of analysed morphological characteristics, hybrids were placed in-between parental taxa, while at the same time, values of different genetic parameters were mostly higher in hybrids than in parental species. The results revealed a high contrast in the levels of phenotypic variability and epigenetic excitation between parental taxa. Environmental niche modelling confirmed that in the studied location S . officinalis experiences optimal climatological conditions, while S . fruticosa struggles with unsuitable conditions. Very low levels of gene flow between the parental species were detected. In addition, contrasting levels of epigenetic excitation in the studied groups clearly demonstrated the importance of an epigenetic response to an altered environment and confirmed the trans-generational nature of the epigenetic changes.

ddRAD Sequencing-Based Identification of Genomic Boundaries and Permeability in Quercus ilex and Q. suber Hybrids

“…Such an alteration of epigenetic characters has been reported, for instance, in Spartina ( Salmon et al., 2005 ) or in Solanum ( Marfil et al., 2006 ). On the contrary, Radosavljevic et al. (2019) obtained similar estimations of introgression levels using markers sensitive or insensitive to methylation in Salvia officinalis and S. fruticosa hybrids.…”

Additive and non-additive epigenetic signatures of hybridisation between fish species with different mating systems

“…Most of the studies in plants using methylation-sensitive amplification fragment length (MS-AFLP) indicate prominent additive effects in cytosine methylation patterns, with typical Mendelian inheritance (35,36,54,55) with few examples of non-additive effects in hybrids, potentially related to phenotypic plasticity and adaptation (56,57).…”

“…However, it is unclear to what extent the role of epigenetic modifications in the restructuring of the hybrid genomes is determined by the underlying genetic changes (34). In plant hybrids, both additive (35) and nonadditive (36) effects can modify DNA methylation patterns, the direction of which depends on the initial degree of divergence between parental lineages (37). For example, hybrids between inbred lines of Arabidopsis display non-additive changes in DNA methylation more frequently when parental methylation levels are different, but not when they are similar (38).Thus, epigenetic changes during hybridisation are related to changes in gene regulation and potentially to reproductive isolation which could lead to speciation, but the extent to which these changes are dependent from the genetic background and the distance between the parental species is unclear, particularly in animals (34) .…”

Two new hybrid species of Salvia (S. × karamanensis and S. × doganii) from Turkey: evidence from molecular and morphological studies

“…Although hybridization has not been documented to occur between major clades (i.e. subgenera) of Salvia, hybridization has been documented within subgenera (Epling, 1947;Walker et al, 2015;Radosavljević et al, 2019;Nachychko and Sosnovsky, 2020).…”

“…Sclarea (Hedge, 1960(Hedge, , 1982a(Hedge, , 1982bNachychko and Sosnovsky, 2020) and subg. Salvia (Hedge 1982a(Hedge , 1982bRadosavljević et al, 2019). The Plant List (TPL: http:// www.theplantlist.org/tpl1.1/search?q=Salvia; accessed 22 June 2020) listed 17 hybrid species as "accepted" while another 17 hybrid species were listed as "unresolved. "…”