Studies On The Progeny Authenticity Of Azalea Hybrids Based On Morphological Markers And Molecular Markers

Azalea is an important plant group of Rhododendron in the Ericaceae family.It is one of the top ten famous flowers in China and has high economic and ornamental value.At present,azalea breeding mainly adopts traditional hybrid breeding methods.However,hybrid breeding is often contaminated by foreign pollen,causing the problem of mixing of true and false offspring.Therefore,identifying the authenticity of hybrids is a very important part of the process of azalea breeding.In this study,6 parents and 88 hybrid progeny of the three cross combinations of R.pulcherum‘Zihe’×R.‘Red Apple’,R.pulcherum‘Baihe’×R.‘Pink Bubble’and R.‘Zibo’×R.‘Kirin’were used as experimental materials,based on the morphological identification method and The EST-SSR molecular marker method is used to conduct early authenticity identification research on the hybrid progeny of azaleas,and the research results provide technical support for improving the breeding efficiency of new azalea hybrids.The main findings are as follows:（1）The variation trends of 9 phenotypic traits in 94 Rhododendron samples were analyzed and summarized.Genetic analysis was carried out based on the correlation between the traits.The results showed that the phenotypic traits of Rhododendron hybrid F₁generation were widely separated and had rich variability.Through correlation analysis of quantitative traits,it was found that the correlation between leaf length,leaf width and leaf length and leaf width,flower diameter and pedicel reached extremely significant level or significant level.According to the genetic distance,it can be inferred that the combination of R.pulcherum‘Zihe’×R.‘Red Apple’and R.pulcherum‘Baihe’×R.‘Pink Bubble’are all true progeny,and the progeny of R.‘Zibo’×R.‘Kirin’is difficult to be identified according to the morphological characteristics,and further research should be carried out in combination with other identification markers.（2）Through independent design and literature reading from 49 primers screened in 15 to EST SSR primers as Rhododendron hybrid progeny identification tags,and the genetic diversity of these tags for statistics and analysis results show that all the 15 pair of primers with high polymorphism and generality,among them,the primer S14、S1、R29、R28 and R26 identify the highest efficiency,can be used as the core primers for effective screening of Rhododendron hybrid progeny（3）15 pairs of EST-SSR primers were used to perform PCR amplification on the total DNAof parents and progeny,and 88 hybrid progeny were identified in batches using fluorescent capillary electrophoresis detection technology,and cluster analysis was performed on 3 hybrid combination populations.The results showed that all the progeny tested were true progeny,and at least two pairs of primers were needed to identify all hybrid progeny.Variations of varying degrees appeared in the three cross combinations,but they were not exactly the same as the genetic variation of morphological statistics.In this paper,the authenticity of 88 hybrid progeny of 3 azalea cross combinations was studied by morphological identification and molecular marker identification.The results showed that all tested samples were true progeny;EST-SSR fluorescent molecular markers can easily carry out azaleas.Early identification of hybrid offspring.The use of molecular identification to improve the breeding efficiency of azaleas is of great significance for accelerating the breeding process of new azalea hybrids.