De novo transcriptome analysis of peduncle neckingin cut Rosa hybrida cultivar ‘H30’

Bent-neck or ‘necking’ is a phenomenon often seen in cut roses, whereby the flower head droops due to a bending of the peduncle. Necking is thought to be caused by a blockage of the xylem, either due to an air embolism or an accumulation of contamination, limiting water uptake to the flower head and causing the stem to bend. Despite the use of biocides to reduce contamination levels, necking remains an issue for the cut flower sector and roses continue to die prematurely. As the occurrence of necking varies widely within and between cultivars, a transcriptome analysis of cut Rosa hybrida cultivar ‘H30’ has been carried out to investigate the potential molecular mechanisms involved. Peduncle samples of three stages of necking (straight, <90° and >90°) were sequenced using next generation sequencing to produce over 100 million reads per stage and 203,565 contigs following Trinity de novo assembly. Differential expression analysis revealed nearly 2,000 significant transcripts (p adjust <0.05); providing a new resource for further analysis into the process of necking.
Keywords: Rosa hybrida, de novo, transcriptomics, bent neck, necking