| The purpose of this study is to analyse the combining abilities and gene effects of quality and some agronomic characters in common wheat varieties "Jinan-17"ect. on a 5×5 diallel cross(without reciprocals) and estimate genetic parameters of each trait. In addition, the relationships of combining ability are discussed between quality and agronomic traits. The main results from this study are as follows:1. The analysis of combining ability reveals that both GCA and SCA variances are significantly different for all quality traits except for sedimentation, glutenin and mixing time where SCA variances are not significantly different. So, the additive effect makes great contribution for sedimentation, glutenin and mixing time, while the additive effect and dominance effects are important for the other traits. The variance ratios of GCA/SCA are considerably higher, showing the additive effect is more important for all quality traits except for final viscosity. The analysis of combining ability about GCA and SCA variances are also significantly different for all agronomic traits except spikelets/spike, kernels/spike, spikes,plant height form index and the upper internodes where SCA variances are not significantly diffent. The results indicate that the characters of spikelets, kernels/spike, spike, plant height form index and upper internodes are controlled by additive genes, and the other traits are controlled by both additive and non additive genes. 2. The value of GCA effects varies with parent and trait. It is different for the same trait in different parents, for example: the variation range of GCA effects is from –0.71 to 1.08 in wet gluten, which is from –21.08 to 38.45 in falling number; The value of GCA effects is also different for the same parent in different traits, such as Jinan-17, which is –24.11 in weight, while it is 39.45 in falling number.3. The value of SCA effects of different combination studied varies significantly in different traits. It is very different for the same combinaton in different traits, which is impossible for the same cross on all characters that the values of SCA effects are all heigh. Such as cross 3×5: there are 16 traits that the value of SCA effets is positive in 17 quality properties. The value of 8 min curve tall which is heigher in all crosses is 1.39, as well as peak heigh, trough and peak viscosity, while the value of weigh is lower; The value of SCA effects varies obviously for the same character in different combination, such as grain yield. The variation range of SCA effects is from –2.04 to 5.46. There are 6 crosses that the value of SCA effects is positive in all crosses.4. For the characters which show higher additive gene dffects, the performance of parents was consistent with their GCA effects. Significantly positive correlation is foun between F1 and SCA effects, but the former was simultaneously influenced by GCA effects. To obtain desirable combinations, therefore, the emphsis should be put on the evaluation of SCA on the basis of GCA of the parents. 5. The relationship between agronomic and quality traits in GCA effects. For GCA effects, there is a negative correlation between grain yield and weight,whiteness,trough, pasting tempereture,whereas a positive correlation between grain yield and the other quality traits, specially, grain yield and hardness show significant positive correlation; Kernels/spike and spikelets show significant positive correlation with breakdown , which show significant negative correlation with pasting tempereture; There is significant positive correlation between spike length and falling number, as well as grain weight/spike and test weight; 1000-kernel weight show significant negative correlation with setback, which is the same relationship in plant heigh and falling number; None of the quality traits show correlation with spike. 6. The relationship between agronomic and quality traits in SCA effects. There is a closely correlation of agrnomic and quality traits for F1 combination. Grain yield show a n... |
