Occurrence of polytene chromosomes in the bicellular and mature pollen grains of endangered plant species Pancratium maritimum L. (Amaryllidaceae)

摘要: AbstractEndoreduplication is a modified form of mitotic cycle in which repeated rounds DNA replication occur without chromosome segregation and cell division, leading to formation larger thicker chromosomes called polytenics. In the present study, spontaneous polytene generative nuclei pollen grains Amaryllidaceae, presumably angiosperms, was described for first time. For this purpose, microspores mature pollens endangered species Pancratium maritimum L. were examined by light transmission electron microscopy with special reference observation polytenic nuclei. Polytene detected most cells young bicellular found some anther locules, but they rare or absent other locules. Polytenization did not follow same pattern all grains. structures developing ...