Genetic Analysis Of Main Seed Quality Characters In Maize

In this Study, 7 main inbred-lines in production and 7 new inbred-lines were crossed based on the NCII(7 7) design.These inbred-lines and the obtained 49 hybrids were used for analyses of the Genetic rules of maize seed quality characters.The main results are the following:1.The genetic components and heritabilities of the main seed characters: (1) Additive effects were found important for seed width, volume weight, Ileand Arg etc;additive and non-additive effects ware equally important for weight per 1000 seeds,specific gravity,protein content Lys.Asp and Gly, etc;non-additive effects were found important for the remaining characters. (2)The heritabilities of seed width,volume weight,protein content,Val, lie and Leu etc were relatively high and those of yield per plant, seed length,specific gravity, Met and Phe,etc,were relatively low. The heritabilities of the other characters were in the middle.The narrow heritabilities of all the characters were low,less than 50%.2.The results of analyses of the Combining Ability of Maize seed characters showed to be compliated:(1)The GCA's of different characters were different in the same inbred line,and the GCA's of the same character were different in the different inbred-lines. (2) The values of GCA of each Character might be positive or negetive for different parents,The probabilities were almost equal.The GCA of different character might be positive or negative in the same inbred line,the probabilities were different in the different inbred lines.The SCA of all the character in different hybrids might also be positive or negative, The probabilities were also almost equal.(3)In the lines studied, lines No 2,6,14 showed a high GCA in all characters; line No.4 was low values of GCA in the main nutritive quality characters, but the values of GCA of the commercial quality characters(weiqht per 1000 seeds, specific gravity, volume weight) and the yield per plant were relatively high in this line.The hybrid combination(2 X 12)was high in both guality and yield.3.The analyses of correlation among seed characters and among the Combining Abilities, the correlations between the mean parent values and the FI hybrids showed that positive correlations were found among in the main nutritive quality characters,among the commercial seed quality characters,between the yield per plant and the main seed quality characters, between the GCA and SCA of the main seed nutritive quality characters,between the GCA and SCA of the seed comnercial quality characters,between the GCA and SCA of the yield per plant and the seed nutrition quality characters. Complicated correlations were found between the seed nutrition characters and the commereal seed characters, between the Combining Abilities of the seed nutrition Characters and the commercial seed characters. In Characers of seed length, seed width,weight per 1000 seeds, volume weight, protein content, fat content and Lys etc, significant or highly significant correlations were found between the mean parent values and the values of the FI hybrids. Positive correlations were also found between the mean parent values and the F] hybrids in seed yield and the remaining majority of quality characters.4.Analyses of principal components and clustering showed that 5 principal components could explain 83.191% of the total variance. The squared Eaclidean Distances between the parents ranged from 0.342 to 21.910.The parental lines couald be clustered into 7 groups.The genetic characteristics and the applications of these characteristics to maize breeding were discussed.