Genetic Diversity And The Construction Of Fingerprints For New Maize Inbred Lines Revealed By SSRs

The materials used in this study were 59 new maize inbred lines utilized in maizeinstitute of Sichuan Agriculture university and passed the identification of uniformitystability and distinctness, of which the genetic diversities were studied by SSR molecularmarkers. 20 of 59 maize inbred lines were constructed DNA fingerprints database. Themain results of study were summarized as follows:1. Primers with high polymorphism in these new inbred lines and core-primers for 20inbred lines to construct DNA fingerprints were screened.2. SSRs (Simple Sequence Repeat) were used to detect genetic diversities among 59maize inbred lines. Fifty-eight SSR primers screened were produced 681 polymorphicamplified fragments. The average number of alleles per SSR locus was 11.7, ranging from2 to 25. The average PIC (Polymorphism Information Content) value per SSR locus was0.83±0.107, ranging from 0.34 to 0.94. Genetic similarities among the 59 inbred linesranged from 0.61 to 0.93 with an average of 0.73±0.032.3. 59 inbred lines were divided into ten groups by UPGMA (Unweighted Pair GroupMethod Agrithmetic Average) according to genetic similarities based on SSR markers:some inbred lines belonged to four familiar groups occupied 78 percent, of which belongedto Lancaster group occupied 12 percent, belonged to Tangsipingtou group occupied 10percent, belonged to Lvdahonggu group occupied 5 percent, belonged to reid groupoccupied 51 percent which were divided into two sub-groups. The pedigree among theinbred lines not only were kindred but also had inherited diversity. The other inbred linesdivided into six groups which occupied 22 percent. The result meant there were biggishdiversity between these groups and other four groups. The pedigree of some known inbredlines were analyzed. The result of clustering by SSR were well consisted with family tree.4. The study selected 17 primers from 80 SSR primers to construct fingerprints of 20inbred lines, which could amplified one piece of stabilized band among most of materialsand had the high polymorphism and could be distinguished from all materials. 17 primersscreened were produced 73 polymorphic amplified fragments. The average number ofalleles per SSR locus was 4.3, ranging from 2 to 8. 5. 9core-primers including phi080, phi123, umc1061, phi126, phi065, dupssr13,phi102228, bnlg240, phi083, were screened to construct fingerprints of 20 inbred lines.Some primers could amplified differential band for single material, some primers couldamplified differential band for two materials, for instance phi065 was differentialmolecular marker to Mo17 and huangzaosi; phi080 was differential molecular marker toSAM1001 and huangzaosi. 6 inbred lines, including SAM1001, dan340, SCML103,Mo17, 441950, SCML202, were selected differential molecular marker, which werediscriminated from others by one pair of primers respectively, huangzaosi had two pairs ofdifferentia primers such as phi080, phi065; the other inbred lines were discriminated withprimers combination.6. The repetition of 9 primers were validated. When the reaction system and reactionprogram were adjusted, the type and relative location on the polypropylene acyl amic gel of thedifferential amplified band would not been modified. The result showed SSR molecularmarker had well stability and repetition and utilized SSR marker in constructing DNAfingerprints were tried.