Studies On Genetic Relationships Of Petunia Hybrida Inbred Lines Using Morphological Traits, ISSR And SRAP

Petunia hybrida is an annual or perennial herbaceous flower, which originated from South America and is widely used in parttere culture. The heterosis of Petunia is prominent. The study on the genetic relationships between parents of Petunia inbred lines can provide the theoretic evidence for parent choosing and heterosis predicting. In this study, the genetic relationships between 15 Petunia inbred lines were estimated using morphological, ISSR and SRAP markers, with the application of systemic clustering analysis and principal components analysis. The main results were presented as following:1. The 15 inbred lines were clustered into 4 groups based on 16 morphological traits. The results of principal components analysis showed that the width of calyces and the length of pedicel is the principal factor affecting the classification of these 15 inbred lines according to morphological characters.2. 38 sets of IS SR primers were tested on preliminary tests, of which 8 sets of primers were used to analyze the steadily produced, well-defined and stable amplification products. A total of 109 bands were observed, Among which, 100 bands were polymorphic (91.7%), The 15 inbred lines were clustered into 4 groups based on the ISSR datas by the method of clustering analysis.3. There were 60 sets of SRAP primer combinations which combined with 10 forward primers and 6 reverse primers. Based on preliminary test, 8 sets of primers were used to analyze the steadily produced, well-defined and stable amplification products. A total of 83 bands were observed. Among them, 75 bands were polymorphic (90%), The 15 inbred lines were clustered into 4 groups based on the SRAP data by the method of clustering analysis.4. The study on the genetic diversity of 15 inbred lines was made by integrating the ISSR and SRAP datas. These 15 inbred lines were classified into 5 groups with method of systemic clustering analysis.5. Comparison of the datas obtained by molecular markers was made by the method of Mantel test. The r correlation value scope was 0.11—0.46, while the r correlation value between ISSR and SRAP marker is 0.11. But it showed the same trends in results between tow markers according to the dendrogram of cluster analysis.