Rose (Rosa ×hybrida) breeders historically have bred plants based on what they personally have deemed attractive and traits required by growers to produce the crop successfully. End-user preferences were not formally considered in breeding decisions. The purpose of this study was to investigate growers’ and consumers’ opinions of roses available on the market and preferences for future roses coming into the market. A web-based survey tool was developed to measure the attributes consumers were considering in purchasing and growing rose plants, their knowledge of diseases and pests, and their hopes for new plants coming to market. A link was sent to horticultural group mailing lists as well as distributed through personal e-mail lists, Facebook, and a news release from Texas A&M University. The survey was posted for 4 months. It included ≈66 questions and took 30 minutes or more to complete. More than 2000 responses were received from rose growers and nursery consumers worldwide. The respondents preferred roses that were disease resistant, with fragrant, abundant, red, and everblooming flowers. The ideal height of the preferred rose shrubs was waist to shoulder-height. Differences were found in preferences between experienced rose growers and those who were not affiliated with rose associations on variables such as the need to use chemicals to manage diseases, the importance of foliage glossiness and large vs. small blooms, the value of roses in the garden setting, the level of difficulty roses pose in growing situations, and the willingness to pay more for a rose shrub in comparison with other garden plants. Differences also were found among age groups and preferences for flower color, fragrance, foliage color, and foliage glossiness. This information could be helpful in targeting marketing of roses.
Tina M. Waliczek, Dave Byrne, and Don Holeman
David Shupert*, Natalie Anderson, and David Byrne
Seedlings from three interspecific backcross rose populations derived from a F1 population were used to study inheritance of several traits in roses. Three F1 plants (WOB13, WOB21, and WOB26) from the hybridization of the diploid parents Rosa wichuraiana and `Old Blush' were backcrossed to `Old Blush' to produced three populations to observe the segregation of several morphological and disease resistance traits. The segregating rose traits in the backcrosses are no prickles on stems, non-recurrent blooming habit, white single flowers, black spot resistance, and powdery mildew resistance present in the Rosa wichuraiana parent compared to prickles on stems, recurrent blooming habit, pink double flowers, black spot susceptible, and powdery mildew susceptible present in the `Old Blush' parent. Visual data was collected for the segregating traits using color standards and rating scales as appropriate. The three populations expressed the segregating traits to varying degrees. Under the environmental conditions at College Station, Texas the population `Old Blush' × WOB26 had a greater expression of the traits for no prickles on stems, recurrent blooming habit, disease resistance to black spot, and disease resistance to powdery mildew, which are traits desired in breeding programs. The segregation of flower color (white/pink), and flower type (single, semi double, and double) were similar in all three populations.
Warner Orozco-Obando, Gwen N. Hirsch, and Hazel Y. Wetzstein
The general doctrine of flowering in Hydrangea macrophylla (Thunb.) Ser. is that floral induction occurs during the fall months with the flower appearing the following spring or summer. However, hydrangea cultivars differ widely in their relative abundance and duration of flower production. The objective of this study was to determine how developmental flowering patterns compared among different hydrangea genotypes. Flowering was characterized in 18 cultivars by assessing flower initiation in dormant buds of 1-year-old stems that received natural outdoor inductive conditions. Terminal and lateral buds were dissected and floral developmental stage categorized microscopically. In terminal buds, flower development was very consistent and occurred in 100% of buds for all cultivars except `Ayesha' (33%). In contrast, lateral buds showed a wide variation in flower induction among genotypes. `Ayesha', `Blushing Pink', `Freudenstein', and `Nigra' had 10% or fewer lateral buds with floral initials. `All Summer Beauty', `David Ramsey', `Masja', `Nightingale', and `Penny Mac' showed high levels of floral induction (>92%). Within a cultivar, flower development was more advanced in terminal than lateral buds. In several cultivars, a significant correlation between bud size (length) and floral stage was found. However, low r-square values indicated that flower stage was explained largely due to factors other than bud length. This study shows that floral induction patterns vary markedly among hydrangea cultivars and provides insight into why cultivars differ in the extent and reliability of seasonal blooming. Genotypes that possess floral primordia in lateral buds would be amenable to cultural practices that enhance lateral budbreak and recurrent blooming.
Kevin M. Folta
genetic control is conferred by SEASONAL FLOWERING LOCUS (SFL; Brown and Wareing, 1965 ) and in rose it is encoded by RECURRENT BLOOMING (RB; Semeniuk, 1971 ). As rose and strawberry are phylogenetic neighbors, it may be assumed that a common mechanism
David H. Byrne, Patricia Klein, Muqing Yan, Ellen Young, Jeekin Lau, Kevin Ong, Madalyn Shires, Jennifer Olson, Mark Windham, Tom Evans, and Danielle Novick
species is used as a source of resistance (or other trait), the cycle becomes longer, as the first step would be to convert the wild germplasm into a remontant or recurrent blooming type. As the recurrent gene is recessive, the initial hybrids are once
Yihua Chen, Peng Jiang, Shivegowda Thammannagowda, Haiying Liang, and H. Dayton Wilde
habit of rose ( Rosa sp.) has been altered by centuries of breeding for the recessive locus recurrent blooming ( Iwata et al., 2012 ). Rb was recently identified as a TFL1 ortholog and rose cultivars with low RoTFL1 expression bloom repetitively