Mitosis and meiosis in plants are affected by the fungicide phosphite

Abstract

To investigate the effect of the fungicide phosphite on mitosis, Vicia faba and Petunia hybrida were sprayed with 0, 2.5, 5 and 10 g/L phosphite, and V. faba was also soil drenched using 5 g/L phosphite. In V. faba, phosphite increased the number of abnormal mitotic cells in root tips of both sprayed or soil drenched plants. The effect was evident 12 h after treatment and persisted for 14 days in young V. faba plants, 21 days in mature V. faba and 14 days in P. hybrida. Phosphite did not affect the proportion of cells undergoing mitosis in either species, or the karyotype of V. faba. Phosphite reduced pollen fertility in plants of P. hybrida and Tradescantia virginiana treated with 0 to 20 g/L phosphite, but the effect was most marked in P. hybrida where pollen fertility was zero for a period between 7 and 14 days after treatment. Pollen fertility was still reduced 21 days after treatment. Phosphite increased the number of abnormal meiotic cells at all stages in T. virginiana microspores but the numbers were insufficient to totally account for the observed drop in pollen fertility