Sequencing viral siRNAs to identify previously undescribed viruses and viroids in a panel of ornamental plant samples structured as a matrix of pools

•Deep sequencing of siRNAs allowed de novo assembly of contigs to identify viruses.•Samples could be pooled before deep sequencing without loss of virus detection.•Detection of 27 previously unknown viruses, including all types of viral genomes.•Ornamental sector could be the source of novel plant diseases in all types of crops.