Cytomorphological and Sterility Studies in Digitaria polevansii Stent

Abstract

Detailed meiotic studies carried out in D. polevansii which was found to be highly pollen-sterile revealed that it has a somatic chromosome number of 2n = 36. This is the first report on the cytology and chromosome number of this species. Analysis of pachytene chromosomes has shown that this species contains two different types of chromosomes. In a few cells that were normal, bivalents were mostly observed at diakinesis and metaphase I. Information obtained through the analysis of chromosomes at pachytene, diakinesis, and metaphase I clearly indicates that D. polevansii is an allopolyploid. Several meiotic irregularities that are characteristic of desynaptics are reported. In addition to the desynaptic phenomenon it is also suggested that there might be some type of physiological imbalance causing disintegration of chromatin material and failure to form the cell wall.