Inheritance of garden rose architecture and its association with flowering behaviour

Abstract

International audience<p>Understanding the genetic basis of plant architecture is limited for woody plants due to the challenges of assessing the inheritance of their complex architecture. We aimed to evaluate the genetic variability of plant form and stature in a garden rose population, analyse the inheritance of plant architecture and its linkage with flowering behaviour and identify the quantitative trait loci (QTLs) controlling garden rose architecture. A total of 98 F 1 hybrids were derived from the cross between two diploid roses, The Fairy (TF) and Rosa × wichurana (RW) that differed in stature and flowering behaviour. The TF exhibits continuous flowering (CF) and has erect stature. The RW is once flowering (OF) and prostrate in stature. Three clones per genotype were multiplied, and a total of 300 plants were cultivated in a field. Flowering behaviour, plant form, plant height, stem diameter and internode length were scored during each of 2&nbsp;years. All architectural traits had significant genetic variances (29–61&nbsp;% of their respective phenotypic variances), and their broad-sense heritability estimates were 0.76–0.92. The majority of CF progeny was erect, whereas the OF progeny was prostrate, suggesting a linkage between plant form and flowering behaviour. The QTL analysis identified eight major QTLs controlling architectural traits. Several candidate genes involved in gibberellin biosynthesis and auxin signalling were identified in the vicinity of the QTLs. High heritability estimates obtained for garden rose architecture indicated that architectural characteristics are feasible targets of rose breeding. Linkage of plant form and flowering behaviour, however, prevents independent selection of these traits. The candidate genes identified can be good targets for future physiological studies.</p

Heritability of Plant Architecture in Diploid Roses (Rosa spp.)

“…Plant height was found highly heritable with a moderate narrow-sense heritability (h 2 = 0.50) and high broad-sense heritability (H 2 = 0.82) ( Table 5). This finding was consistent with estimates reported previously by Gitonga et al (2014) (H 2 = 0.82), who measured this architectural component on potted tetraploid cut-flower rose populations, and by Kawamura et al (2015) (H 2 = 0.88), who studied the architecture of a small (98 individuals) diploid garden-rose population. Both studies reported broad-sense heritability only and have smaller populations and fewer families than our study.…”

“…Our results, combined with previous studies (Crespel et al, 2014;Kawamura et al, 2015) that reported high broad-sense heritability for several architectural traits of garden roses, indicated that rose plant architecture was a feasible target for rose breeding. Architectural traits with low narrow-sense heritability but moderately high to high broad-sense heritability, such as the number of primary shoots, the length of the primary shoot, and the number of nodes on the primary shoot, indicated important nonadditive effects.…”

“…The broad-sense heritability of rose architectural traits has been estimated using a set of eight diploid rose cultivars grown in pots in a greenhouse (Crespel et al, 2013(Crespel et al, , 2014, a small (98 individuals) F 1 diploid population planted in the field (Kawamura et al, 2011(Kawamura et al, , 2015, and a biparental F 1 tetraploid cut flower population that was planted under greenhouse conditions in the Netherlands and Kenya (Gitonga et al, 2014). In general, researchers found that the architectural traits they measured during the first flush of growth after dormancy (gardenrose situation) or pruning (cut-rose situation) showed a moderate to high broad-sense herita-bility.…”

Characterization of black spot resistance in diploid roses with QTL detection, meta-analysis and candidate-gene identification

“…-OW population (151 individuals) was obtained from a cross between R. chinensis 'Old Blush' (OB), susceptible to BSD, and RW (Lopez Arias et al in press;Hibrand-Saint Oyant et al 2018;Soufflet-Freslon et al 2019), -HW population (209 individuals) was generated from a cross between a dihaploid rose named H190 (Meynet et al 1994), susceptible to BSD, and RW (Soufflet-Freslon et al 2019), -FW population (96 individuals) resulted from a cross between the cultivar 'The Fairy' (TF) and RW (Kawamura et al 2015). In the Earth-Kind® Trials using detached leaf assay, TF was shown to be susceptible to pathogen races 3, 8 and 9 (Zlesak et al 2010).…”

Ornamental plants architectural characteristics in relation to visual sensory attributes: a new approach on the rose bush for objective evaluation of the visual quality

“…This primary structure was labeled in this study as the 'elementary architectural system'. Proximal axes sprouting at or under the substrate level, sometimes called 'renewal canes' (Zieslin and Mor, 1981) and empirically seen as total reiterated complexes (Costes et al, 2014;Kawamura et al, 2015) V o l u m e 8 3 | I s s u e 3 | J u n e 2 0 1 8 191 of an 'elementary architectural structure stage' (Crespel et al, 2013;Li-Marchetti et al, 2015), were denoted also as first branching order axes. These axes and all their descendants were further labeled as forming the 'delayed architectural systems'.…”