Study On Genetic Diversity Of Lycoris Ornamental Species

Species included in the genus Lycoris Herb, are important ornamental and medicinal plants. Their main producing area is in china. There are approximately twenty species of Lycoris all over the world including fifteen species in china. In the study, from the viewing angle, the forty-six populations from ten species which have obvious variation in morphology were collected, the genetic diversity was estimated from both the interspecies and intraspecies using RAPD and ISSR molecular markers combining morphological features, which provided a theoretical basis for resource conservation and new varieties breeding of Lycoris.In the study, an optimized PCR reaction system for RAPD and ISSR was established, 33 RAPD primers and 15 ISSR primers were screened. For RAPD marker, the 33 primers employed produced 623, 328, 329 and 308 scorable amplified fragments from L.albiflora, L.longituba, L.radiata and the interspecies of Lycoris respectively, which include 527, 117, 100, 194 polymorphic loci. The rate of polymorphism were 84.6%,35.67%,30.4% and 62.99% respectively; for ISSR marker, the 15 primers employed produced 119, 112, 105 and 149 scorable amplified fragments from L.albiflora, L.longituba, L.radiata and the interspecies of Lycoris respectively, which include 102, 70, 42, 100 polymorphic loci. The rate of polymorphism were 85.71%,62.5%,40% and 67.11% respectively. The genetic distance and genetic similarity coefficient matrix of two molecular markers were established according to the data, and the dendrogram which reflects the overall trend was also established according to the analysis of the correlation between the two molecular markers.The result of the research has indicated the genetic relationship of 10 species of Lycoris. It could be draw from the dendrogram that L.radiata and L.rosea, L.albiflora and L.houdyshelii, L.longituba and L.chinensis have high genetic similarity. According to the dendrogram of intraspecies, the populations of L.albiflora, L.longituba and L.radiata could be clustered into nine groups, five groups, four groups respectively, and there was a high correlation between RAPD and ISSR, indicating that the two methods were highly consistent and suitable for detecting genetic diversity and genetic relationships in both interspecies and intraspecies of Lycoris. But based on the theory and the fact of integrated trees, we believe that the marker of ISSR is more suitable for Lycoris studying than the RAPD marker.