| The basic research material is F1which was crossed between Rbl and Rb2, and then F1plants were crossed by pollen from "Jing Ke You005" haploid induction line.181doubled haploid lines were obtained by artificial doubling. Those181doubled haploid lines and Rbl and Rb2were used for this study. On the one hand, the phenotypic value of plant-height, ear-height, kernel-weight per ear, ear-length, bald-length, rows per ear and100-kernel-weight was investigated. Simultaneously, the group separation of those traits was analyzed. On the other hand, the inbred lines Rbl and Rb2and the181doubled haploid lines were respectively crossed with the key lines S121and Zheng58, and then366Hybrids were obtained. And the phenotypic values of plant-height, ear-height, kernel-weight per ear, ear-length, bald-length, rows per ear and100-kernel-weight of366Hybrids were recorded. In addition, the analysis of combining ability, heterosis, genetic parameters, the main characters and correlation was also carried out by applying the principles of quantitative genetics. The main research achievements were as follows:1.The plant-height, ear-height, kernel-weight per ear, ear-length, bald-length, rows per ear and100-kernel-weight of181DH lines were investigated and analyzed.The results showed that, firstly, the absolute value of the kurtosis and skewness of frequency distribution of plant characters were less than1. in line with normal distribution. Secondly, there was a significant variation between DH lines groups, but this phenomenon is different according to different traits. The highest variation degree was bald (61.91%), the second was single grain-weight (32.99%) and the lower variation degree in plant-height and rows per ear (13.40%and13.65%, respectively). SSR markers were used to test genetic segregation in the DH populations. There was no significant segregation distortion in populations.2. The analysis of GCA, SCA effects and genetic parameters of traits was conducted, based on the principle of the quantitative genetics. The findings suggested that the difference of GCA effects of the plant-height, ear-height, ear-weight, ear-length, bald-length and ear-number between DH lines achieved extremely significant level, except that of100-kernel-weight. The differences of SCA effects of the plant-height, ear-height, ear-weight, ear-length, bald-length, rows per ear and100-kernel weight between hybirds achieved extremely significant level. In addition, the additive variance value of the plant-height, ear-height, ear-weight, ear-length, bald-length and rows per ear were significantly greater than dominance variance value, except that of the100-kernel weight,which illustrated that the genetic effect of those traits mainly attributed to additive effects and could improve its related traits by improving the choice of parents. Heritability estimates indicate that the value was great of broad-sense heritability and narrow-sense heritability of plant-height, ear-height and ear row number, therefore, it could be concluded that the selection in early generation of those traits was reliable. On the contrary, the value of narrow-sense heritability of other traits was low, which indicated that these traits were susceptible to environment.3. The comparative analysis of the value of GCA, SCA in main traits between181DH lines and two inbre line Rbl and Rb2was carried out. The results showed that, compared with parents Rbl,181DH lines were likely to produce a beneficial separation in plant-height and in other triats which were not easy to have a beneficial trait, and they also have very favorable separation. In contrast to the parent Rb2,181DH lines were likely to produce a beneficial separation in ear-length, kernel-weight per and100-kernel-weight, and in other traits which were not easy to have a beneficial traits, they also have very favorable separation.4. The relativity analysis of the value of GCA in main traits between181DH lines was carried out. The results suggested that the positive correlation between the plant-height and the ear-height were extremely remarkable, the positive correlation between the ear-height and bald-length were remarkable, and the negative correlation between rows per ear and kernel-weight were extremely remarkable. The positive correlation between the ear-height and the ear-length were extremely remarkable, and the positive correlation between the the ear-height and the rows per ear, plant-height, grain-weight were remarkable, but the correlation between the the ear-weight and ear-height, bald-length was low. the multiple regression and path analysis for the plant height, ear height, ear length, bald long, rows per ear,100-kernel weight and grain weight was carried out by using the SAS9.0software. The results indicated that the yield was significantly correlated with ear height, ear length, rows per ear. The multiple regression model between single-grain weight and traits is yΛ=-1.00434E-8+0.26476X6+0.45578X3+0.38187X5. The relativity analysis between the phenotypic value and the GCA effect value showed that the Correlation between GCA and phenotypic was remarkable. |
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