Karyotype Features of 17 Species of Spiraea and Karyotype Parameters Analysis Photosynthetic adaptability of the resistance ability to weak light of 2 species Spiraea L. Karyotype Features of 17 Species of Spiraea and Karyotype Parameters Analysis Association Analysis of Ornamental Traits with RAPD Markers in 18 Portion Materials of Spiraea L. Morphology Structure of Leaf Epidermis of Genus Spiraea in Heilongjiang Province