Genetic Studies On Improved Maize Germplasm

In recent years, with the improvement of the gradual growth of corn, the study of corn improvement is also becomes more important, this experiment mainly selected differences larger 12 corn backbone system and improvement of system as the experimental material, adopt augmented NCII design made up into 35 hybrid combinations, and the generation of the son of main agronomic traits and quality traits, a total of 13 characters of data for analysis. Using data from corn backbone system is analyzed and improvement is the character of heterosis and combining ability and heritability and yield with other agronomic traits traits genetic correlation analysis and path analysis. The main test results are as follows:Heterosis analysis:the selection of inbred lines equipping all heterosis combination are widespread, and has some advantages more than the control group of more than 8% yield. And most traits in average and transgressive positive part is greater than the negative part. All 35 is the super portfolio performance advantages, advantages of 39.28%～39.28%, and the performance is super advantages, advantage of 31.93%～31.93%. Combination of 355 x C2 contrast in yield XY 335 increase 20%.General combining ability showed that 352,355, C3, C4 and inbred lines in plant height, ear position better traits, and 354,358, C1, C5 in hundred grain weight, bald tip length, grain number, characters better. And 355 by the combination of C2 is the strongest heterosis, and yield GCA of the best inbred lines 354,354, C2.Through the analysis of the genetic parameters of the various characters, ear length, ear rows and ear diameter, ear position, the four traits, their broad sense and narrow sense heritability value is larger, that they are less affected by environmental factors, when the choice can be selection in early generation; In bald tip length, stem diameter of these two traits, broad sense and narrow sense heritability is very low, they receive a greater influence on the environmental factors, can’t in early generation selection; Line number, seed yield of grains per ear, these two characters in terms of broad sense and narrow sense heritability gap is bigger, genetic stability is poor.Yield to other agronomic traits analysis:plot correlation coefficient between yield and main traits from big to small in turn:stem diameter, row number of grains per ear, axle load, ear, ear weight, ear diameter, bare tip length, ear length, hundred grain weight, seed yield, plant height, coarse. The table shows that stem diameter, row number of grains per ear, axle load, ear, ear weight, ear coarse, bald tip length, ear length and plot yield were positively correlated. Various agronomic traits of production according to the direct path coefficient of size for:stem diameter, ear position, axle load, bald tip length, ear length, ear diameter, seed yield, ear row number, hundred grain weight, ear weight, ear row number, plant height, coarse. Stem diameter, ear position, axle load, bald tip length, ear length, ear coarse through direct effect yield.