2019 ASHS Annual Conference

Single Molecule Real-Time (SMRT) sequencing is a powerful technology that is rapidly changing the field of plant genomic and genetic research. Long sequencing reads produced by this technology have made it possible to overcome multiple inherent challenges that large, highly repetitive and complex genomes create for genome sequencing and de novo genome assembly and to examine gene structures and splice variants. Gerberas (Gerbera xhybrida) are one of the most popular flowers in the global floricultural trade for their bright and attractive flowers. They are grown mainly as cut flowers and also as flowering potted or garden plants. The large size (5.5 Gb) and heterozygous and highly repetitive nature of the gerbera genome make it difficult to conduct genomic research in this flower. In this study, we report the first use of PacBio SMRT sequencing in gerbera and identification of the nucleotide binding-site leucine-rich repeat (NB-LRR) class of disease resistance genes (R-genes), the most common R-genes in plants. The genomic DNA of a powdery mildew-resistant gerbera line was sequenced using the PacBio RSII platform and the P6-C4 chemistry to a depth of about 3x. Sequenced reads had an average N50 of 16.7 kb, a mean read length of 11,894 kb, and a mean read score of 0.84. NB-LRR genes in the gerbera genome were identified using the available homologous sequences from the sunflower and lettuce genomes.