Trichomes micromorphology and cytological investigation on Acinos alpinus subsp. meridionalis in Algeria

Anatomical and karyological features were investigated in four populations of Acinos alpinus subsp. meridionalis (Nyman) P. Ball., an Ibero-Maghreban species. Plant material was collected in the field during flowering stage, in contrasting bioclimatic conditions. Fresh material was used for analysis of trichomes morphology with light microscopy. Young meristems and flower buds were fixed for karyological analysis. Two types of capitate glandular, one type of peltate glandular, and four types of non-glandular trichomes were observed on different parts of the plants, including the stems, leaves and flowers. Trichomes distribution and density showed variability among organs, but no intraspecific variability was found. The chromosome number 2n = 2x = 18 is reported for the first time for Algerian populations. Furthermore, aberrant meiotic behavior in the form of cytomixis was observed in one population of A. alpinus subsp. meridionalis – cytoplasmic strand was formed between more than two cells at different stages of meiosis. Other types of abnormalities such as lagging chromosomes, and formation of triads with microcytes were also discovered. Results are discussed in comparison with literature.