Spindle Abnormalities in Mentha

Abstract
A study was made of meiosis in M. spicata, M. piperita, and several of their interspecific hybrids regarding the transmission and behavior of a gene-determined abnormality which upsets spindle development in the pollen mother cells. Abnormalities were associated with variations in the structure and time of development of the spindle. In M. spicata, 50% of the pollen mother cells showed the abnormality but the range of variation was narrow. M. piperita showed no spindle abnormalities. All of the hybrids showed it, but in a varying % of the cells. The range of variation was wide. The abnormality appears to be controlled by a partial dominant gene.