Breeding Of Day-neutral Multiflora Chrysanthemum And Genetic Analysis Of Flowering Time

Day-neutral multiflora-chry santhemum can fuifill flower bud differentiation and flower bud development under long-day or short-day conditions,which has a very broad application prospect in production.In this research,the author developed the breeding goal of cultivating Day-neutral multi-chrysanthemum.Based on the investigation of germplasm resources,the mathmatical analysis,24 multi-chrysanthemums were seleceted as cross breeding parents;and based on light of beijing,Day-neutral multi-chrysanthemum select critrrion was made.The hybrid population with more Fi was used as the experimental material to analyze the heterosis and genetic model of the flowering time inheritance of multi-chrysanthemum.Results are as follows:(1)The authors developed the breeding goal of cultivating Day-neutral multiflora chry santhemum with large plant type and high double-flowering.After analysis of different trairs,24 excellent series were screened out from the resources e according to an analytic hierarchy process(AHP)and weighting of the grey relational grade.(2)Based on 24 seleced multiflora chrysanthemum,the genetic distance between 552 hybrid cross was calculated by principal component analysis and cluster analysis.The three-dimensional coordinate analysis was used to select the most suitable female parent and male parent.37 hybrid combinations with different genetic distances were finally selected,and 790 flower heads were finally crossed,obtained 6,418 seeds.(3)According to the light time of Beijing,876 hybrid offsprings in the bud stage,early flowering stage,full flowering stage and late flowering stage were calculated,and 106 days were selected according to the definition of Day-neutral multiflora chrysanthemum.19 strains with excellent comprehensive traits were finally selected.(4)The results of heretosis analysis showed that heretosis and transgressive segregation were ubiquity in these important quantitative characters in F1 progenies.The results of main gene+polygene mixed genetic model in plant quantitative traits showed that the traits of height,Crown diameter and late flowering were in accordance with OMG model,without main gene control,and may be controlled by multiple genes with greater environmental impac.Leaf bud and squaring stage were in accordance with 2MG-A model.Initial flowering stage and ray flower are consistent with 2MG-ADI model.Full flower stage is consistent with the lMG-AD model.The flowering duration is consistent with the 2MG-AD model.In conclusion,the author draw main conclusions of this study:mathematical analysis methods plays an important role in multiflora chrysanthemum breeding.Establishing grading index based on the photoperiod response of the plant is an effective method for quantitative analysis of the flowering time.Sexual hybridization technology is still an effective technical way for small chrysanthemum breeding.