Comparative anatomy and pollen morphology of two endemic Noccaea species (Brassicaceae) and their taxonomic significance

This study was conducted for extensive and systemic investigation of anatomical, palynological and seed morphological properties of two endemic Noccaea species, naturally growing in Turkey. Independent sample T-test and box plot were carried out using quantitative characters of the studied species. The anatomical results showed that the species had similar characteristics, though there were significant differences in root cortex cells and trachea; stem epidermis, cortex cell and endodermis; leaf upper and lower epidermis, lower cuticle, mesophyll and palisade parenchyma.  Pollen grains of two endemic species were observed as radially symmetric, isopolar, with tricolpate aperture, prolate pollen shape and had small size. Pollen surface ornamentation was micro-reticulate in both species. Considering palynological characters, equatorial axis, AMB exine and intine have taxonomic importance. Seeds of N. birolmutlui were ovate to orbicular in shape and orange-brown in color, with colliculate ornamentation; however, the seeds of N. camlikensis were ovate to oblong in shape and brown and shiny in color, with colliculate-reticulate ornamentation

AUTECOLOGY AND CONSERVATION BIOLOGY OF CENTAUREA AMAENA (ASTERACEAE)

Centaurea amaena is an endemic plant species that is under critical risk of extinction and was known from only one population in Kayseri, Turkey. During our research another locality was found at about 15 km distance from the first known population. In this study, the population pattern of this species and its distribution, the reasons for its narrow range, its pollen viability, stigma receptivity, and the breeding system have been identified, and practical efforts have been carried out for conservation. Pollination experiments showed that C. amaena pollination mechanism allows first for allogamy and then secondary pollen presentation and that the timing pollen viability and stigma receptivity are asynchronous. The seed-to-ovule ratio was calculated as 35%. According the tetrazolium staining viability test, the seed viability also was determined as 82.6%. The main factor threatening the species were identified to be anthropogenic-related (including construction, over-grazing, tourism), and some strategies have been developed for the purpose of conservation it