摘要
Ⅰ. INTRODUCTIONIn pollen mother cell (PMC) of wheat pollen-derived haploid, there are only 21 chromosomes (n=21), each of which lacks its homologous partner, thus the meiosis is abnormal and results in the production of the microspores varying in size. Among them, some very small microspores which contain only a few chromosomes packed in a micro-
