The Analysis Of Homology From Inbred Lines And Relative Quality Traits Based On SSR Marks Of Maize

Maize is an important forage crop and it is very important to obtain high yield and high quality maize.However,in the actual production process,there exist phenomena such as single species and serious homogenization.The main reasons under analysis are as followings,the narrow genetic background of germplasm,relatively backward technical reserve,insufficient germplasm resources,slow and long period of basic research,and lack of attention to quality in the process of practical breeding.Therefore,it is of great significance to study the improvement and innovation of maize inbred lines.In this experiment,there 259 maize inbred lines with complex pedigrees(including 10 domestic standard test inbred lines)were used as materials,selecting 30 of polymorphism SSR markers and combining the technology of capillary electrophoresis(CE)to precede genotyping for the test materials.PowerMarker software was used to calculate genetic distance between inbred lines and to analyze homology,and MEGA software was used to construct a population map of 259 maize inbred lines.Meanwhile,the near infrared grain analyzer was used in this study to determine the content of undamaged quality of corn grains and analyze the correlation of quality traits.The main results are as follows:1.In this experiment,there 10 standard test inbred lines were used as test population,and 20 pairs of core primers were used to compare and analyze CE and polyacrylamide gel electrophoresis(PAGE).The results showed that there were 12 pairs of primers which cannot be clearly distinguished the difference between genotype in PAGE,and they can be clearly showed differences in CE.Therefore,10 pairs of primers with good polymorphism and uniform distribution in 10 chromosomes of maize were screened by CE from 100 pairs of common primers,which 30 pairs of SSR markers were used in this experiment together with 20 pairs of core primers.2.According to SSR marker analysis,all that 228 alleles variants were detected in the tested inbred lines.There 7.57 alleles are detected in average for each primers,and the PIC averaged 0.69.The primer umc1705 and the primer phi96100 were the most primer of PIC(0.86),and the primer bnlg240 was the smallest primer of PIC(0.37),and the genetic diversity averaged 0.73.3.The genetic distance of 259 maize inbred lines ranged from 0.27 to 3.37,with an average genetic distance of 1.37.There were 0.39% of the genetic distance of maize inbred lines concentrated between 0.00 and 0.50,16.65% concentrated between 0.50 and 1.00,51.9% concentrated between 1.00 and 1.50,25.08% concentrated between 1.50 and 2.00,4.41% concentrated between 2.50 and 3.00,1.19% concentrated between 2.50 and 3.00,and 0.38% concentrated between 3.00 and 3.50.The genetic distance between the inbred line 17W1339 and the inbred line 17W1343 was the smallest(0.27).and the genetic distance of 14 pairs of maize inbred lines was the largest(3.37).4.By UPGMA cluster analysis method,259 maize inbred lines were divided into 8 major groups,which were mainly divided and named according to 10 backbone inbred lines in China.The first group was the Modified Reid,with a total of 25 inbred lines,accounting for 9.65%;The second group is the Reid,with a total of 63 inbred lines,accounting for 24.32%;The third group is the PA(modified Reid group II),with a total of 11 inbred lines,accounting for 4.25%;The fifth group is the Lu da Red Cob,with a total of 39 inbred lines,accounting for 15.06%;The sixth group is the Sipingtou,with a total of 47 inbred lines,accounting for 18.15%;The seventh group is the Lancaster,a total of 56 inbred lines,accounting for 21.62%;The eighth group is the Zi 330 subgroup,consisting of only 7 inbred lines,accounting for 2.70% of the total;The fourth group is the special group that does not contain standard test inbred lines and consists of 11 inbred lines,accounting for 4.25% of the total.5.Correlation analysis of main quality traits(protein,fat,bulk density,and starch)of 259 maize inbred lines was carried out by near infrared grain analyzer.The results showed that there was a significant positive correlation between protein and fat,protein and bulk weight.The bulk weight was significantly positively correlated with fat content.There was a significant negative correlation between starch and fat,starch and bulk weight,starch and protein content.