Generalities
Rosa species are one of the most economically important ornamental plants. Their popularity as garden flowers and cut flowers, but also their use for cosmetics and perfume industry, is constantly increasing. The Rosa genus includes about 150 perennial species and shows a great diversity of ploidy levels. (di-, tri-, tetra-, penta-, hexa-, octo-, decaploid).
It has a small genome (about 560 MB or 4 times the genome of Arabidopsis thaliana), and international effort is underway to achieve its complete sequencing. The rose has a relatively short life cycle for a perennial plant (one year after germination of the seeds, the seedlings can flower) and its genealogy is well documented. Several teams around the world, particularly in France, are studying the molecular and genetic bases that govern certain characteristics of this plant, such as flowering date, flower shape and colour, vase life for the cut flower, resistance to pathogens and perfume.
These molecular and genetic data, as well as the development of genetics tools for the rose, make it a model of choice for ornamental plants.
- Name: Rosa sp.
- Phylogenetic classification: Rosaceae family, Rosoideae subfamily.
- Genome sequenced depending on species (e.g. Rosa chinensis sequenced in 2018 (Raymond et al.), Rosa multiflora sequenced in 2018 (Nakamura et al.))
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Genome size: Approximately 560 million base pairs, varies slightly between species.
Number of genes predicted: Between 30,000 and 35,000 genes.
Reproduction
Roses are self-incompatible. Pollination is entomogamous (meaning pollen is mainly carried by insects). The stamens are numerous and the carpels are inserted on a hollow receptacle, the hypanthium, which protects them and allows the styles and stigmas to emerge.
After fertilization, the carpels evolve into achenes, contained in the fleshy rosehip, resulting from the evolution of the hypanthium. Interspecific hybridization is frequent in nature and most polyploid species are derived from it, and for these we speak of an allopolyploid origin.
Ploidy differences are an important barrier to varietal improvement, since most cultivated varieties are tetraploid, which is a barrier to the introgression (dispersion of genes from one species to another, since the two are interfecund) of traits of interest from wild diploid species.
In nature, vegetative propagation is common. It takes place through the emission of specialized stems, the suckers, which, after the plant that emitted them has been freed, give an independent clone. The rose’s ability to be cut (vegetative propagation) is widely exploited for its industrial multiplication, as is the possibility of grafting an axillary bud onto a rootstock.
Tools
- Crossbreed populations from several varieties of Roses
- EST database (genes expressed during flower induction and during flower development)
- Gene mapping
- Collection of several species and varieties (Lyon and Lyon Botanical Garden)
- Genetic transformation protocols (in particular diploid rose; Vergne et al., 2010)
- In situ hybridization (Dubois et al., 2010)
- High speed microarray (Affymetrix, 5,000 gènes) (Dubois et al., 2011)
- RNAi (functional analysis of genes of interest by expression of interfering RNA)
Databases
Infrastructures
- Laboratoire Reproduction et Développement des Plantes (RPD) UMR 5667 - ENS de Lyon
- http://www.ens-lyon.fr/RDP/
- Lyon
- Laboratoire de biotechnologies végétales appliquées aux plantes aromatiques et médicinales (LBVpam) - FRE CNRS 3727 - EA 3061
- https://www.univ-st-etienne.fr/fr/lbvpam.html
- Saint-Etienne
- Institut de Recherche en Horticulture et Semences (IRHS)
- https://www6.angers-nantes.inrae.fr/irhs/
- Beaucouzé
Experts
- Manuel LE BRIS
- manuel.lebris@imbe.fr
- Institut Méditerranéen de Biodiversité et d’Ecologie marine et continentale UMR CNRS7263 IRD237 AMU UAPV Marseille
- Mohammed BENDAHMANE
- mbendahm@ens-lyon.fr
- Laboratoire Reproduction et Développement des Plantes, UMR INRA978 CNRS5667 UCBL ENS-Lyon, Lyon
Bibliography
- Books
« Genomic and Breeding Resources: Plantation and Ornamental Crops, Rose. » Smulders et. al., C. Kole (ed.), Wild Crop Relatives: Genomic and Breeding Resources Plantation and Ornamental Crops, 2011.
« Encyclopedia of Rose science » Roberts et. al., Elsevier Academic Press, Amsterdam, Netherlands, 1450pp, 2003.
- Articles
« Genomic approach to study floral development genes in Rosa sp. », Dubois et. al., PLoS ONE, 2011
« Polyploidisation mechanisms: Temperature can induce diploid gamete formation in Rosa sp. », – Pecrix et. al., J Exp Bot., 2011
« Tinkering with the C-function: A molecular frame for the selection of double flowers in cultivated roses. », Dubois et. al., PLoS ONE , 2010
« Versatile somatic embryogenesis systems and transformation methods for the diploid rose genotype Rosa chinensis cv Old Blush. », Vergne et. al., Plant Cell Tiss Organ Cult., 2010
« Scent evolution in Chinese roses. », Scalliet et. al., Proc Natl Acad Sci., 2008
« Analysis of gene expression in rose petals using expressed sequence tags. » Channeliere et. al., FEBS Letters, 2002
- Websites