Abstract:

【Objective】 In order to provide bases for molecular assisted breeding, and for cloning creeping habit related genes from the ground-cover chrysanthemum, the inheritance traits of creeping habit were studied, and the RAPD markers related to this habit were screened. 【Method】 F1 population was derived from interspecific cross between ‘Zaoyidalihong’ (female parent) and ground-cover chrysanthemum ‘03(6)-12’ (male parent). The plant type was divided into creeping, erect and intermediate (non-creeping and non-erect) types according to the branching angle of main branches. Individuals of each plant type in F1 were randomly selected, and self-cross was made to generate the F2 population. BC1 population was obtained from back cross of the selected individuals with ‘03(6)-12’. The segregation ratio of different plant types was documented in seven populations. The gene bulk of creeping and erect plant type in F1 population was constructed by using bulked segregant analysis (BSA) method. 200 RAPD arbitrary primers were used to screen creeping habit related molecular markers. 【Result】 Genetic analysis and chi-square test showed that creeping or erect type in ground-cover chrysanthemum likely controlled by an incomplete dominance major gene as well as polygene. A RAPD marker A-10555 linked to creeping gene were screened, the validity of this RAPD maker was verified by replicate tests and testing individual plant in F1 population, the maker was 7.96 cM far from the loci controlling creeping/erect 【Conclusion】 It is feasible to divide plant type into creeping, erect or intermediate types by branching angle of main branch, F1, F2 and BC1 population were useful population for segregation investigation of plant type in ground-cover chrysanthemum. The marker obtained in this study is closely linked to loci controlling creeping or erect, and is promising in molecular assisted breeding.

Key words: ground-cover chrysanthemum, creeping, genetic analysis, bulked segregant analysis (BSA), RAPD marker