Virus-Infected Pollen Grains inPaeonia emodi

Abstract
Tubular virus particles, 25 × 190 nm in length, reacting strongly in gel diffusion tests and immunoelectron microscopy to tobacco rattle virus antiserum, were detected in pollen grains of a plant of Paeonia emodi. Relative to leaf cells, the pollen grains contain virus in high concentration, particles being arranged side by side in long crystalline arrays distributed randomly throughout the cytoplasm. Presence of the virus is correlated with anomalous pollen development and degeneration of mitochondria and other organelles. The observations are discussed in relation to male sterility and pollen dimorphism in this plant and its failure to respond in anther/pollen culture.