| Maize is the important grain and feed crop with crucial economic significance which played an enormous role in economy development and social stability. However, ear is the most important harvest organs, is also the direct effects in maize production. It is more and more important for ear traits researching in maize with the increase requirements for maize in society. The excellent inbred line Yu82 and Zong3 respectively crossing with Yu87-1 derived two RIL populations were the objects in this study, which take the phenotypic identification of corn ear traits in three different environments, using the constructed SNP molecular markers genetic linkage map to mapping and analysis genetic effects for ear traits through the method of composite interval mapping, using composite interval mapping method based on mixed linear model to analysis the effects of epistasis of ear traits and the interaction effects for environments, screening the major QTL which can express in multiple environments and two populations, analysis the “consistency” ear traits QTL through the element analysis method. The major results are as follows:1. Two genetic linkage maps constructed which covered 10 chromosomes of maize contain 1179 and 1243 SNP markers. Two maps spanned a total of 1884.8 c M and 1864.0 c M with an average interval of 1.599 c M and 1.500 c M independently. The two genetic maps integrate into a map which contained 1890 SNP markers, the total length of integration was 1928.39 c M and the average distance was 1.020 c M.2. The ear traits of two RIL populations were identified at three different environments. The results show that all of the traits in two populations show continuous variation with transgressive segregation on one side or both sides, fitting normal distribution. Through correlation analysis other traits are significant or extremely significant correlation except row number and kernel number as well as kernel number and cob diameter.3. Using the composite interval mapping method, 31 QTLs for ear length, 31 QTLs for ear diameter, 27 QTLs for row number, 24 QTLs for kernel number, 32 QTLs for cob diameter, 19 QTLs for 100-kernel weight were detected based on two RIL populations in three location environments. The contribution to phenotypic variation for single QTL varied from 5.01% to 24.31%. The major QTLs which contributions are greater than 10% are 8 QTLs for ear length, 6 QTLs for ear diameter, 7 QTLs for row number, 3 QTLs for kernel number, 7 QTLs for cob diameter and 4 QTLs for 100-kernel weight. There were 14 QTLs in the same interval which were detected in more than two environments, in which the contribution greater than 10% of QTLs’ number were 7 at least one environment: the QTLs on chromosome 2 for ear length, the QTLs on chromosome 2 for row number, the QTLs on chromosome 4 for 100-kernel weight and the QTLs on chromosome 1 and 2 for cob diameter. These QTLs were not sensitive to location environments, as we can have the further research. Through epistatic analysis there were epistatic QTLs, however the contributions to phenotypic variation were not large enough.4. By using the software Bio Mercator4.2 to analysis “consistency” ear traits QTLs in two RIL populations. There were 25 m QTLs detected, which contained 89 QTLs. Each m QTL integrated 2-7 QTLs, and 1-5 traits. Comparing the QTL result in two populations there were 7 m QTLs consistent in two populations. We found that 5 m QTLs were detected which constructions were greater than 10% in at least one population. They were the QTLs interval PZE-101144216 ~ PZE-101144740( bin1.06) on chromosome 1 and the interval PZE-106083335 ~ PZE-106077743( bin6.05) on chromosome 6 for row number, the interval PZE-104016174~PZE-104032151(bin4.03-4.04)on chromosome 4 and the interval PZE-108086184~PZE-108089808(bin8.05-8.06)on chromosome 8 for ear length, the interval PZE-104035759~PZE-104123974(bin4.05-4.06)on chromosome 4 for ear diameter. The interval PZE-101233287~SYN22772( bin1.1-1.11) as well as PZE-104016174 ~ PZE-104032151( bin4.03-4.04)、PZE-104035759~PZE-104123974(bin4.05-4.06)、PZE-104118502~PZE-104116111(bin4.08)on chromosome 1 and 4 integrated 5 or 4 ear traits. These QTLs which controlled the different traits were adjacent to each other, which were used can be multiple effects. |
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