Establishment Of DNA Fingerprinting Of Maize Variety With SSR Marker

Core primers were defined and multiplex PCR was studied by SSR marker. At the same time, DNA fingerprints of maize hybrids and their parents were established. This study was reference for "Research on Establishing DNA Fingerprinting database of Chinese New Maize Cultivars" and the purity and reality identification of maize cultivars. The results were summarized as follows:1.60 maize inbred lines were analyzed using SSR technics. Sixty-two pairs out of one hundred and sixty pairs of SSR primers were selected, which gave polymorphic, stable and repeated amplification profiles. All 60 inbred lines were distinguished with several primer compose while that could not do with single primer.2.62 SSR primers screened were analyzed and finally a set of core prime pairs fitting for establishing maize inbred line and hybrid DNA fingerprinting map were confirmed, which were bnlg439, bnlg!25, phi053, bnlg197, phi072, bnlg238, phi126, bnlg161, bnlg240 and bnlg619. At the same time a formula for calculating existence probability of maize SSR-DNA fingerprint was advanced: P=1/N,for inbred lines, N=n; for hybrids, N=Cn1+Cn2. n is the allele number of the primer pairs.3.Twenty-one pairs of maize SSR primers were used for building various multiplex-PCR-sets according to their amplified bands' size range. Under the same conditions as single PCR reaction, 47 two-PCR-sets appeared five different amplification behaviors, of which 30 were amplified normally. Nine of 10 three-PCR-sets and one of 2 four-PCR-sets were amplified normally. These screened normally-amplified multiplex-PCR-sets could be applied in maize DNA fingerprinting database. The results suggest that most multiplex-PCR-sets could be amplified normally under just the same conditions as single PCR. Based on our experience, we proposed a simplified protocol for developing a multiplex PCR assay.4. DNA fingerprint map of maize hybrids and their parents with 14 SSR primers. The complement type of two parents was the optimal one for distinguishing hybrids and their inbred lines. The appearance of the maternal type and the paternal type was probably caused by incomplete purity of inbred lines or the parents of the hybrid werenot original. The appearance of double bands in several inbred lines by some primers was probably caused by electrophic difference between positive and negative DNA chains. The fingerprinting of maize hybrids which appeared to be complement of their parents can identify the purity and reality of maize hybrids quickly and precisely.