Research On Classfication Of Heterotic Groups Of Hybrid Wheat Parents

In order to discover the collocation regulation among hybrid wheat parents, 15 common wheats match 84 cross combination by NCⅡdesign.According to F1'phenotypic expression,anylisis of parental combining ability and SSR molecular marker,heterosis groups are divided in selected materials.To enlarge hereditarybasis of hybrid wheat parents,heterosis groups are divided on 147 wheats from different areas in China by making further use SSR molecular marker.The results are as follows:1.The heterosis of hybrid F1 is ubiquitous.8 agronomic characters investigated performed mostly positive advantage,the hetirosis differs greatly in various characters.The sequence of characters over mid-parent heterosis'meanperformance is single plant yield>kernel yield per ear>1000-seed-weight>plant height>ear lengh>grain number per main ear >spikelet number of main ear >spike number per plant.2.Through the analysis of heterosis among 6 different groups,it is concluded that the intermediate type×more spikes type is the parental combination type with strong heterosis.3.The result of the analysis of combining ability showed that the GCA were significantly different among diverse parents.The SCA were also obviously different among various hybrid combinations.The SCA of strong heterosis combinations are mostly higher, and most of the single-parent's GCA or the sum of parents'GCA are higher; on the contrary, the SCA of weak heterosis combinations are relatively low, and the parents'GCA are low as well. There is no necessary relationship between the SCA and GCA.4.Except over-standard heterosis of grain number per main ear,variety of hetirosis are correlated with the SCA of combination and the sum of parents'GCA respectively,but the correlation coefficients is no significant.Moreover,the peformance of various characters are correlated with the SCA of combination and reach a significant level.5. 15 wheat parents were divided into five groups by general combining ability of eight characters and the performance of eight characters, respectively. 89 SSR primers detected 291 alleles in sixteen common wheat, and the average number of alleles per SSR primer was 3.27, ranging from 1 to 8. Sixteen common wheat were classified into six groups by UPGMA (unweightied pair group method agrithmetic average) based on GS (genetic similarity) from SSR molecular marker. 6. SSR was used to divide heterotic groups among 147 common wheat.32 SSR primers produced 125 alleles, and the average number of alleles per SSR primer was3.91,ranging 2 to 6. 147 common wheat were classified into nine heterotic groups by SSR molecular marker.