Allelopathicpotential of volatile oil from Chenopodium ambrosioides L. on root tip cells of Vicia faba Immunofluorescent Observation of Micro tubule Cytoskeleton in Root Tip Cells of Sagittaria sagittifolia L. Microtubule Cycle in Root Tip Cells of Allium fistulosum L. The Optimization of Chromosome Preparation and Immunofluorescence Staining for Root Tip of Nelumbo nucifera Radiation Protective Effect of Polysaccharide from Spirulina platensis on Plant Cells from Radiation Genetic Damage