Structure, Ultrastructure of the Anther, Pollen Microsporogenesis and Morphology of Pollen Grains of Two Populations of Lygeum spartum L. in Algeria

Problem statement: The Lygeum spartum L. represented by a single species occupies several regions of the Mediterranean basin. This plant plays an important ecological role in the fight against desertification and economic development in the manufacture of paper pulp. Approach: However, the cytogenetic studies in mitosis in this species revealed the existence of two ploidy levels: 2n = 40 among the population grows in the coastal region of Oran in the semi-arid climate and 2n = 16 in the high plateaus characterized by an arid climate. Results: The study of the anther, pollen grains and the meiotic division conducted on these two populations of Lygeum spartum L. growing in the two regions has confirmed these data in that the microscopic observations were used to determine the ultrastructure of the anther, the shape and size of pollen grains which morphometric data (L/W) showed significant difference between the two populations. The microsporogenesis was followed on the mother cells of pollen grains in order to understand the formation of tetrads, then the enumeration of chromosomes was carried out in diakinesis (n = 20) for the coastal population of Oran and metaphase I (n = 8 ) for the population of the high plateaus. Conclusion/Recommendations: These results were consistent with what has been observed in mitosis, which suggested that the Lygeum spartum L. may submit two cytotypes to adapt to different geographical and climatic environments.