Research On The Genetic Characteristics Of J1185and Its Improved Lines In The Core Collection Of Maize Non-Reid Group

In this study,J1033,J1133,J1072,PH6 WC,and J1029 were used as female parents,and 25 hybrid combinations were formed by using the backbone line PH5 AD of the Non-Reid group,the core germplasm J1185 and its improved lines J1259,J1255,and J1263 as the male parents.On this basis,the genetic gain,significant difference(compared with Xianyu 508),heterosis,general combining ability,special combining ability and genetic parameters of each improved line and hybrid combination were analyzed and compared.Lines and hybrid combinations,and broaden the utilization of germplasm resources provide reference.The test results are as follows.1.The results of genetic gain analysis showed that the genetic gain values of yield traits such as single plant yield,100 grain weight,spike weight and spike length gradually increased with the increase of improvement rounds and showed an increasing trend,and the second round improved lines Y2 and Y5 had better improvement effects;the genetic gain values of agronomic traits such as plant height and spike position increased with the increase of improvement rounds and showed a decreasing trend,and the second round improved line Y2 had better improvement effects.The number of male branches in the second round of improved lines showed a decreasing trend with the increase of improved rounds;there was no obvious improvement effect of bald tip in the two rounds of improved lines.2.The mean value of parental dominance in single plant yield was the highest 132.82%,and the range of variation was 104.57%-147.14%.The hybrid combination Z6(J1033×J1259)had the highest single plant yield heterosis advantage(147.14%),followed by the combination Z7(J1133×J1259)with a heterosis advantage of 142.57%,indicating that the second round Y2(J1259)was easy to assemble a variety with a high single plant yield heterosis advantage.3.The results of general compatibility analysis showed that the second round improved line Y2(J1259)had the highest values of stem thickness,spike length,spike thickness,spike weight,row grain number,100 grain weight,single plant yield,plant height and spike position effect;the second round improved line Y4(J1255)had the highest value of spike row number effect;the second round improved line Y5(J1263)had the lowest value of axle thickness and axle weight effect.The above analysis showed that the second round improved line Y2(J1259)had the best overall performance and had some potential for application in improving maize crosses.4.The results of the special combining power analysis showed that Y2(J1259)had more positive effect values from the comprehensive analysis of the special combining power results,among which the combination with the highest single plant yield special combining power was Z7(J1133×J1259)and the combination with the highest 100 grain weight special combining power was Z6(J1033×J1259)and the improved line Y2(J1259)was assembled as the male parent,and it performed well in the number of ear rows,ear weight,yield per plant and other traits,indicating that Y2(J1259)can be used as an ideal parental self-replicating line for improving yield traits and plant type,and has good potential for application.5.Genetic gain analysis showed that the broad-sense heritability of all traits reached more than 50%,with the maximum spike length(94.66%)and the minimum single plant yield(61.39%),and the narrow-sense heritability of all traits reached more than 50%,with the maximum spike weight(60.33%)and the minimum 100 grain weight(50.62%),indicating that the inheritance of spike length,single plant yield,spike weight and 100 grain weight is little influenced by the environment The genotypes of spike length,single plant yield,spike weight and 100 grain weight were highly similar to each other,mainly controlled by additive genes,and the hit efficiency of genotypes judged by expression was high,which was suitable for selection in early generations.In conclusion,the above analysis showed that the second round of improved line Y2(J1259)has the best comprehensive traits and has some potential to be used in improving maize hybrid combinations.