A Search for Phylogenetically Informative Pollen Characters in the Subtribe Salviinae (Mentheae: Lamiaceae)

Abstract

The pollen morphology and ultrastructure of the subtribe Salviinae were investigated with light, scanning electron, and transmission electron microscopy. In addition, cladistic analyses of the obtained morphological data, supplemented with rbcL data from GenBank, were conducted in order to assess the phylogenetic signal of palynological characters. Salviinae pollen is small to large, oblate to prolate in shape, with a circular to slightly elliptic amb, and mostly hexacolpate. Perovskia abrotanoides appears to be distylous and shows a significant pollen dimorphism between pin and thrum flowers. The sexine ornamentation of the genera Lepechinia and Chaunostoma is perforate, while the ornamentation of other genera is bireticulate. Perovskia expresses a unique type of sexine ornamentation. The sexine ornamentation variation in Salvia has systematic importance but only partly corresponds with current phylogenetic hypotheses. Unbranched columellae and a continuous, granular endexine are hypothesized to be a symplesiomorphic condition in the tribe Mentheae. Our combined phylogenetic analyses show that the addition of palynological characters contributes to improved resolution and also increases bootstrap support values in comparison with molecular phylogenetic analyses.

Pollen morphology of Hymenosphace and Aethiopis sections of the genus Salvia (Lamiaceae) in Turkey

“…An operculum with granule was seen in all the taxa (Figures 1-3). Similarly, some authors (Perveen and Qaiser, 2003;Moon et al, 2008c;Hassan et al, 2009) found colpi with granulate membranes and pointed, acute, and obtuse ends. The exine is semitectate (Walker, 1974;Hamzaoğlu et al, 2005;Jafari and Nikian, 2008) and muri are simply columellate (Figures 4 and 5).…”

“…These results agree with those of Özler et al (2011) (Figures 1 and 2). Similarly, Moon et al (2008c) The pollen grains of the Salvia taxa examined are small to large (P = 25.0-61.4 µm, E = 30.7-67.2 µm). The smallest pollen occurs in Salvia aethiopis, belonging to sect.…”

“…Hymenosphace (Table 2; Figure 1). Hamzaoğlu et al (2005), using the Wodehouse method, and Moon et al (2008c) and Hassan et al (2009), using the acetolyzed method, found some differences in the size and shape of the Salvia species examined. These differences can be mainly caused by different preparation techniques.…”

“…There are a large number of studies on pollen morphology in Lamiaceae (Erdtman, 1945;Cantino et al, 1992;Harley et al, 1992;Cantino, 1993, 1994;Celenk et al, 2008;Moon et al, 2008aMoon et al, , 2008bMoon et al, , 2008cSalmaki et al, 2008;Hassan et al, 2009;Aytaç et al, 2012), but only a few studies have been conducted on Salvia (Henderson et al, 1968;Jafari and Nikian, 2008;Hassan et al, 2009;İlçim et al, 2009;Kahraman et al, 2009aKahraman et al, , 2009bKahraman et al, , 2010aKahraman et al, , 2010bKahraman et al, , 2010cKahraman et al, , 2011Kahraman and Doğan, 2010;Celep et al, 2011;Özler et al, 2011). Henderson et al (1968) gave brief descriptions of the pollen morphology of 59 Salvia taxa, 20 of which grow in Turkey.…”

“…Henderson et al (1968) gave brief descriptions of the pollen morphology of 59 Salvia taxa, 20 of which grow in Turkey. Moon et al (2008c) studied the pollen morphology and ultrastructure of 32 taxa of Salvia (subtribe Salviinae). Özler et al (2011) studied pollen grains of 30 taxa of Salvia, belonging to sections Salvia, Horminum, Drymosphace, Plethiosphace, and Hemisphace, using light microscopy (LM) and scanning electron microscopy (SEM).…”