Analysis On Genetic Relationships And Breeding Potential Of 14 New Selected Maize Inbred Lines

In this study,70 crosses were made by NC Ⅱ design with 14 new selected maize inbred lines and 5 testers which often used inbred lines(Dan598,Chang7-2,P138,Mo17) in China. Through analyzing the combing ability.heterosis and genetic indexes of main traits estimated the 19 inbred lines. Analysis the genetic diversity and population structure of the 14 new selected maize inbred lines and 19 often used inbred lines by 31 SRAP makers.lt is preparation for the heterosis groups and heterosis pattern.The main results as follows:l.The general combing ability analysis indicated that the GCA of all traits were significant at 0.05 or 0.01 level apart from the GCA of leaves number,100-kemel weight of testers. ZixuanSC232, ZixuanZW411, ZixuanZW515, ZixuanZW192,ZixuanZW112 have better breeding potential because of the higher performance on the GCA in grain yield and yield component traits.The other inbred lines have poor performance on the GCA,recommending as a germplasm preservation.2.The result of 70 crosses SCA showed that the combination ZixuanSC232 X Dan598 indicated the maximum SCA positive effective for ear length,rows per ear,kemels per row and plant weigh.The combination ZixuanZW611 X Mo17 showed the maximum SCA negative effective for ear length, plant weigh and shelling percentage.Combined with previous analysis of GCA Showed that most of the combination of high SCA,their parents or one of parents are high GCA, low SCA combination, their parents are all low GCA, but there are special combinations, which high GCA of parents, showed low SCA.Showed that the performance of Hybrids output are result of both GCA and SCA. So based on GCA selection in maize hybrid breeding and the choice of SCA should be strengthened.3.The higher broad and narrow heritability of the tassel branch number,ear length,ear diameter, rows per ear and 100-kemel weight of the broad sense heritability and narrow sense heritability were higher than 50%.And this showed these characters were mainly influenced by genetic factors, which should be chose in the early generation.The tasseling stage,silking stage,plant height,ear height, shelling percentage,kemels per row and plant weight were higher in broad sense heritability but lower in narrow sense heritability,and they were accessible the environment.4.The results of 31 SRAP primer pairs analysis showed that a total of 196 alleles were amplified,with an average of 6.32 alleles per primer pair,the polymorphic rate averaged 53.08%,ranging from 40.00%-70.59%.The genetic diversity averaged 0.5495,ranging from 0.2156-0.8854, and the PIC averaged 0.5507, ranging from 0.1809-0.8976.5.Results from the clustering analysis based on a model-based method indicated that the 33 materials could be divided into 4 groups. There are 12 inbred lines in Reid group,including 7 new selected inbred Hnes(ZixuanZW131, ZixuanZW132, ZixuanZW133, ZixuanZW611,ZixuanZW612,ZixuanZW51 landZixuanZW525).There are 7 inbred lines in Luda red cob (LRC)group, including 3 new selected inbred lines(ZixuanZW191, ZixuanZW192, Zixuan ZW193).Tang si ping tou (TSP) group have 6 inbred lines,including 2 new selected inbred lines(ZixuanZW411,ZixuanZW412).P group (or PB)have 4 inbred lines,including 2 new selected inbred Hnes(ZixuanSC232,ZixuanZW112). SPT group kept minimum Nei’s genetic distance with LRC group,had the most distant genetic relationship with Reid group. The pedigree of some known inbred lines was analyzed.6.Analysis on the heterotic patterns of 15 crosses with the best grain yield,the predominant heterotic pattern was PBxLiida red cob,followed was Reid×Tang si ping tou.ln addition,Reid×PB,PBxTang si ping,Reid×Tang si ping tou were also the good heterotic patterns with good grain yield.The results indicated that good heterosis was found in different groups.