THE RELATION BETWEEN THE CASSIDA NEBULOSA AND HOST PLANTS Ultrastructure of Central Cell before and after Fertilization in Sugar Beet (Beta vulgaris) Gallus Regeneration from Protoplasts of Sugar Beet(Beta vulgaris) Cloning and Sequence Analysis of Nitrate Reductase Gene from Beta vulgaris by RT-PCR Zonation of Seedling of Beta vulgaris and Its Location of Fleshy Tap Root Effects of nitrogen regulation on photosystem II chlorophyll fluorescence characteristics of functional leaves in sugar beet (Beta vulgaris) under salt environment Influence of Inhibitors of Nucleic Acid Synthesis and Protein Synthesis on Glutamine Synthetase Gene Expression Induced by Nitrogen in Sugar Beet (Beta vulgaris L.) Cyto-embryological Study of the Apomixis of the Monosomic Addition Line M14 in Sugarbeet Ultrastructure of Synergid in Its Degenerative Process in Sugar Beet (Beta vulgaris) RACE cloning and bioinformatics analysis of nitrate reductase in Beta vulgaris Ultrastructure of Megagametophyte during the Development Period in Suger Beet(Beta vulgaris L.)