Impact of Manganese on Pollen Germination and Tube Growth in Lily

Abstract

he role of manganese in pollen germination and pollen tube growth. Pollengermination was adversely affected by the presence of manganese (>10−8 M),whereas low concentrations (10−12–10−10 M) stimulated the process. Manganesecaused morphological anomalies during tube growth, characterized by irregularpollen tube thickening and swollen tips. e main effect was the anomalous cellwall formation at the tip, in which the presence of several organelles reduced thenumber of secretory vesicles. A loose network of fibrillar material and sphericalaggregates, mostly in the tip region, was detected, and this material wasprogressively loosened into the surrounding medium. As a response to potentialtoxicity, the excess manganese was isolated in vacuoles, which formed an internalbarrier against penetration of manganese to the tip area. Elevated manganeseconcentrations might affect plant reproduction, resulting in anomalies in gametedevelopment. Consequently, the loss in genetic diversity and decreased fruit setultimately lower yield.