| Chimonanthus praecox L.is an ancient and unique plant species of the family Chimonanthus.It blooms in winter and is an ornamental flower containing medicinal compounds.In the long term cultivation process,the morphological differences of different cultivars of Chimonanthus praecox were bigger,such as flower color,flower type and floral fragrance.The construction of hybrid population is conducive to the analysis of the formation mechanism of these ornamental traits in the future.In this experiment,Chimonanthus praecox lines H29 and H64 were hybridized.H29 as the female,and H64 as male,72 descendants were obtained.The hybrid combinations with H64 as female parent did not get offspring,indicating that there was a significant difference in seed setting rate among different cultivars of Chimonanthus praecox.The authenticity of 72 offspring has been identified by screening and using SSR markers,it was found that the band type of primer Cp-33 in the parent was(aa x bb),and the band type of the progeny was(ab).According to this standard,only 30 of the 72 sub generations were found true hybrids,the true hybrid rate was only 41.67%,and the others might be self breed.This result is related to the pollination mode of Chimonanthus.In the construction of genetic population,the identification of progeny is very important and determines the accuracy and authenticity of the gene location.Therefore,in the genetic analysis of the Chimonanthus,the progeny identification should be a necessary step.In the diversity analysis,10 pairs of primers in 48 pairs of SSR primers(Cp-9,Cp-18,Cp-23,Cp-26,Cp-30,Cp-33,Cp-38,Cp-41 and Cp-44)were found to be polymorphic in the parents.10 SSR markers were used to screen 72 individuals.Only 5 markers(Cp-23,Cp-30,Cp-33,Cp-38 and Cp-41)were polymorphic.The Nie’s genetic diversity(He)and Shannon similarity coefficient(I)of Cp-30 were 0.739 and 1.363,respectively,higher than those of other4 SSR loci.The Nei’s value of false hybrids(0.222)was lower than that of true hybrids(0.263). |
