Title: “RrGT2, A Key Gene Associated with Anthocyanin Biosynthesis in Rosa rugosa, Was Identified Via Virus-Induced Gene Silencing and Overexpression”
“In this study, we cloned and identified the RrGT2 gene from the petals of R. rugosa for the first
time. We carried out detailed bioinformatic and homology analyses of the RrGT2 gene. VIGS results
in perennial Rosa plants under field conditions suggested that RrGT2 is related to the biosynthesis of
anthocyanins in R. rugosa. Stable transformation of the RrGT2 gene in tobacco showed that its
overexpression was positively correlated with the accumulation of anthocyanins. The results of VIGS
in transgenic tobacco also confirmed this conclusion. We verified the functions of the RrGT2 gene in
anthocyanin metabolism in both the positive and negative directions to provide useful information
for subsequent color-improvement projects in R. rugosa.”
H.Kuska comment: Full PDF manuscript is available.
There is something odd about Rosa rugosa … or what passes for it in gardens. There is a tendency to produce white-flowered offspring even though the parents/grandparents all have pink flowers. And in Gustafsson’s example, the absence of a single chromosome somehow blocked anthocyanin production altogether. The only similar example I’ve encountered is in crosses of Dwarf with Tall bearded irises. The DB parent overrides the TB’s anthocyanin choices.
Nyveldt’s White. [(Rosa rugosa rubra x Rosa majalis) x Rosa nitida]
Graham Thomas (1994): "During his experimental work with the parentage of roses at Cambridge in the second quarter of this century, Dr C.C. Hurst raised seedlings of this cross, one of which was named R. x micrugosa ‘Alba’. Apart from being of rather more upright habit, it is in other respects a replica of the original but of important garden value because the white flowers are produced not only at midsummer, but onwards throughout the growing season.
Gustafsson (1944): “R. canina II x rugosa: 1934-4 — This series consists of two individuals. One is a monosomic plant showing almost no trace of the father but also being very unlike the mother. It is smaller and less vigorous than its sister-plant, having few and rather weak prickles, small purely white petals, a light-green colour on stem and leaves, and lacks anthocyanin.”