Study On SSR Fingerprinting Markers And Identification Techniques Of Melon Hybrid Varieties

The hybridized varieties have been widely used in melon (Cucumis melo L.) production, but it will bring severe damage by using the low-rate hybrid seeds. The present investigation was taken up to assess the resolving power of SSR fingerprinting techniques. 16 materials, including 4 parental lines and 12 hybrid melon varieties in China, were analysed to establish a standard procedure for hybrid melon identification. K the reaction condition of SSR amplification: The PCR reaction mixture (25 μL) contained 2.5 μL of 10 X PCR buffer, 2.0 uL of dNTPs (2.5 mM), 2.0 μL of MgCl2 (25mM), Taq polymerase (3units), 1 uL of SSR forward and reverse primers( 5 pmol.μL^-1) respectively, 100ng of template DNA. SSR amplification parameters: 3 min at 94°C, 34 cycles were performed with 30 sec at 94°C, 30 sec at 54 °C, 1 min at 72°C, and a final extension step of 5 min at 72 °C.2 , Establishment of fingerprinting for melon hybrids by SSR markers: 2 melon hybrids ('Dongfangmi No.1' and '01-31') were analyzed by SSR markers to establish the standard DNA fingerprinting for seed test. Ten pairs of primers out of thirty-seven were widespread in melon genome. 2 to 4 alleles were detected by each pair of primers, and 27 alleles were detected in total. The average of the alleles detected was 2.7 per pair of primer. The band size ranges from 85bp to 270bp. Finally, Seven out of 10 pairs of SSR primers were selected to establish fingerprinting for the two hybrids. According to the data above-mentioned, the fingerprinting of the melon hybrids was established and numbered. Then the method to calculate the probability for the fingerprinting of each hybrid were introduced in this paper, and finally the standard and exclusive fingerprinting of melon hybrids was determined to distinguish the truth and falseness of samples in seed test. The experiment showed that SSR technique was practical and effective to identify melon hybrids.3, Genuine identification and application of SSR markers in the purity test of hybrid melon seeds: The polymorphism of 2 melon hybrids (' Dongfangmi No.1' and '01-31' ) and their parental lines were analyzed with SSR marker system. 7 out of 37 pairs of SSR primers, which gave stable and polymorphic amplification profiles in hybrids and their parents,...