The Uniformity Study On Maize Variety Identified By Morphological Characters And SSR Marker

43 morphological characters in maize DUS test and 20 primers studied uniformity of 14 maize hybrids 278 plants, which was for the purpose of reasonable uniformity standards of maize variety identified by SSR marker. Maize DNA of different tissues and Sampling time extracting by DNA quick technique was tested by polyacrylamide and capillary gel electrophoresis, which lay foundation for the prevalence and extent of SSR marker in maize variety identification. The major result were as follows:1. DNA quality of embryo, endosperm, 1d spire, 1～3d coleoptiles, 1～2d adventitious Roots, 1～3d primary and secondary root cultivated in water is good, which fits for testing by polyacrylamide and capillary gel electrophoresis in big scale. Among these materials, endosperm, 1d spire, 1～3d coleoptile, 1～2d adventitious Roots, 1～3d primary and secondary root cultivated in water can be identified in advance, then grow normally.2. The smaller genetic distance of primers on the same chromosome, the higher correlation in the uniformity result, the Polymorphism of primers among genes is higher than primers inside gene, the Polymorphism of primers of short repeat sequence is higher than primers of long repeat sequence.3. Scatter diagram of the morphological differential value and molecular differential value shows plants molecular differential value≥2 are heterotipe. The correlation coefficient of the morpha uniformity ratio and molecule uniformity ratio is 0.98, extreme correlation. So the heterotipe criterion of the molecular differential value≥2 is made.4. The ratio of the common heterotipe in the morphological heterotipe and molecular heterotipe is 0.83 and 0.81 respectively. The correlation coefficient of the morphological standard plant ratio and molecular standard plant ratio is 0.60, significant correlation, and the ratio of the common standard plant in the morphological standard plant and molecular standard plant is 0.65 and 0.83 respectively. So the molecular marker and morphological character is not one to one correspondence, and the differentiating ability of molecular marker is higher than morphological character.5. Based on the above conclusions, using DNA fingerprint method in maize variety uniformity identification, five grade partitioning standard is reasonable.