Study On Utilization Potential Of Maize Inbred Lines In America And Main Species In Southwest China

In this study,SSR molecular markers were used to analyze the genetic diversity of 48 maize inbred lines and 8 inland inbred lines,and UPGMA cluster analysis was used to cluster the maize inbred lines.The results were compared with those of SSR molecular markers.Ten of the 48 inbred lines were selected as the tested lines and eight inland inbred lines were tested.According to the NC? genetic mating design,The results showed that the yield and heterosis of 18 major maize inbred lines were studied by the combination of 3 points(Anshunping dam,Yunnan Luoping,Zunyi Nanbai)The results were as follows:1.41 pairs of primers with clear and stable amplification bands were screened from 180 pairs of SSR primers in 10 pairs of chromosomes.A total of 169 alleles were detected,and each pair of primers detected 2 to 10 alleles with an average of 4.12 fragments.The fragment size ranged from 100 to 600 bp.The average polymorphic information of 41 pairs of primers was 0.661 and the variation range was 0.299(umc2192)~ 0.885(umc2292).According to the UPGMA method,the tested inbred lines were clustered,and 56 samples were divided into seven groups based on the genetic distance of 0.572.2.PHJ90,PHR58,LIBC4,HB8299 have great potentiality in southwest area based on analysis of 10 inbred lines in the United States district general combining ability effect of production value,and their potentiality was PHR58> HB8299> PHJ90 > LIBC4.3.The specific combining ability is the performance of the interaction between the two parents.By analyzing the combination of the top ten of the SCA effect in the 80 groups,what can be seen is that SS × NSS or NSS × SS is Higher in the southwest area with great potential.The results of SCA showed that PHJ90> MBUB>LIBC4> PHR58> PHV07> PHR47> HB8299.The six American inbred lines had a higher potential in the southwest.By analyzing the special combining ability of 80 combinations of plant traits,it was found that the unique germplasm of the United States and the tropical germplasm were used in the United States,and the hybrids were lower and the stem was thicker and adapted to a higher degree of mechanization.It is easy to obtain a better improvement effect because the high ear height and the low degree of mechanization.Analysis of the combined fertility of 80 combinations of growth stages showed that the combination of American inbred lines and southwest tropical populations could shorten the growth period of offspring.The effects of 40 combinations of ASI on the tropical germplasm(S909,Y8201,QR273,CMI171)and 10 tested strains were analyzed.Among them,21 combinations showed negative effects,indicating that the American inbred lines were associated with tropical germplasm group,which can increase the degree of coordination of male and female flowers.4.The yield of the 80 hybrid combinations was between 413.46 kg and 868.06 kg / 666.7 m2,and the total yield was 655.07 kg / 666.7m2.Only two combinations of HB8299 × 8201 and PHR58 × S909 were more than CK(A311 × R69),the yield growth was 6.87% and 1.71% respectively.It is shown that HB8299 and PHR58 are more likely to get high-yielding combinations with the test species 8201 and S909,and have great potential in the southwest region.Compared with the results of cluster analysis,it is found that the yield of hybrid species in the United States and the tropical populations in the southwest region are higher than that in the southwest region.This model is of great value in the southwest area.5.Through the analysis and statistics of 14 agronomic traits and variability of 10 American inbred lines,it was found that 10 American inbred lines had moderate plant height and ear position in the southwest area,and the number of male flowers was less,Shorter growth period,male and female flower coordination and so on.6.The molecular genetic distance is closely related to the SCA effect of each trait,and it is only significantly related to the yield,spike length and 100-grain weight.There was a significant correlation between the yield of the plot and the total combining effect of most traits,and the correlation effect of the general combining effect was 1,and the correlation coefficient with the total yield was the same.The molecular genetic distance was significantly correlated with the TCA effect,such as yield,grain number and 100 grain weight,but had little correlation with plant traits.In general,the correlation between the yield of community and the combining effect of each trait is greater than that of molecular genetic distance.7.The American maize germplasm has the characteristics of strong stalk,low spike,low density,lodging resistance,low grain water content and mechanization.It can be used in the same group with tropical germplasm,As a non-reincarnation of the cross-linked to the southwest of the commonly used tropical blood line back to improve.It can also be divided into different groups based on trait characteristics and breeding objectives.After multiple genetic recombination it can be selected as a parent group selection of materials.In the same way,the representative inbred lines of the Reid population in the southwest can be improved or genetically reconstructed as the material of the parent group.