RFLP ANALYSIS IN CHRYSANTHEMUM .1. PROBE AND PRIMER DEVELOPMENT

In order to study genetic variability at the DNA level in chrysanthemu m (Dendranthema grandiflora Tzvelev) PstI and HindIII genomic librarie s were constructed. Probes from both libraries were tested for the pre sence of restriction fragment length polymorphisms (RFLPs). Of the pro bes from the PstI library 91% appeared to hybridize to low-copy genes, while only 35% of those from the HindIII library appeared to do so. T he PstI probes were used in further analyses as 79% of them showed RFL Ps, whereas the HindIII low-copy number probes gave only 14% polymorph ic patterns. Because of the hexaploid character of chrysanthemum, comp lex patterns generally consisting of 6-12 fragments were visible on a Southern blot after hybridization. To simplify the genetic analysis, l ocus-specific polymerase chain reaction (PCR) primers were developed t hat gave simple polymorphic patterns in a number of cases. The RFLP pr obes and primers developed will be used in future marker-assisted sele ction in this polyploid crop.