Effects of Magnesium Chloride Pretreatment on the Plasma Membrane H+-ATPase Activity and Nitrate Absorption Efficiency of Canna generalis in Farmland Wastewater Dynamic Change of Stomatal Density and Stomatal Index on the Flower during Canna generalis Bailey Development Genomic sequence and pathogenicity analysis of Cucumber mosaic virus Cah1 infecting Canna generalis Bail