Evolutionary pattern of the genus Salvia L.

Bridging statistical model based method with molecular data provide new opportunity to answer one of the main question in biology whether higher richness and diversity in some organism’s lineage is correlated to special traits effect. Angosperms as amajor group of seed plants have huge diversity and include high rate of diversification. Lamiaceae is the sixth largest family among Angiosperms with over 7000 speies distributed in all over the world. Salvia is known as the largest genus in this family including around 1000 species, having two stamens and speial pollination system reffered to as lever mechanism. This character evolved in parallel between the Old World and New World Salvia species. A high percentage of endemism and high morphological diversity are of special interest in understanding the evolutionary patterns within Salvia. Compared to New and Old World Salvia, taxa from Southwest Asia have not been well sampled in previous phylogenetic studies. In this study the phylogenetic relationships of Iranian species of Salvia are reported for the first time. Iran contains 62 species of Salvia of which 19 are endemic and the area is considered as a center of diversity for Salvia in Southwest Asia. In current study, we used the supermatrix of 2 nuclear regions and three chloroplast regions for 250 taxa including 58 of Iranian species to reconstruct the phylogenetic tree in Salvia lineage. Maximum likelihood analysis was performed by RAxML v.8. Our analyses suggest that Iranian Salvia species are not monophyletic and instead they are placed in three main clades. To recounstruct the floral traits, we use the phytools package in phytools package of R, make.simmap function was used for reconstructing discrete charater and fitMk for continuous trait (Corlla length and Tube legth). Linage through time plot diversification have been done by applying ape, laser and DDD packages in R. we also test the effect of corolla length for the role of adaptive radiation in diversification of the genus Salvia, Although we did not achieve early burst of diversification, The rates of subclade diversification are higher than expected under Brownian mode. Since the main subclades have separate geographical ranges, overlap in morphospace is not equal to ecological overlap. We assume independent radiation of subclades among Salvia species. In addition, biogeographic patterns of Salvia in Old World will be discussed and effects of floral traits on diversification will be discussed.

کلیدواژه ها:

Salvia ، diversification ، phylogeny ، Ancestral reconstruction