Abstract: The results of cytological study indicated that the different cultivated density of spring wheat exerted different influence on the development of the microspore of spring wheat: (1)Development of the microspore of the low-density wheat was quicker than that of the high-density wheat at the stage of pollen mother cell,i.e.the pollen mother cell of high- density wheat was just formed and the anther wall did not degenerate while the pollen mother cell of the low-density wheat came to meiotic division,and the anther wall tapetum began to degenerate.(2)During the stages of dyad and tetrad,the pollen mother cell of the low-density wheat developed more quickly than that of the high-density wheat.50% pollen mother cells of the high-density wheat did not divide into dyad and tetrad,or only parts of them formed dyad while 90% pollen mother cells of the low-density wheat formed dyad and tetrad.(3)At the late monokaryon stage of microspore the development of the microspore of the low- density wheat indicated that its major spikes and tillering spikes developed more and more quickly and tillering spikes showec a tendency to carch up with the major spikes in development.However,the development of the tillering spikes of the high-density wheat gradually slowed down or even stopped.

Key words: Spring wheat, Cultivated density, Microspore, Cytotogy