Comparative transcriptome analyses reveal genes related to pigmentation in the petals of a flower color variation cultivar of Rhododendron obtusum

Rhododendron is an important woody ornamental plant and breeding varieties with different colors is vital research goal. In this study, a flower color variation cultivar ‘Yanzhi Mi’ (pink petals) and the wild-type (WT) cultivar ‘Dayuanyangjin’ (white petals with pink stripes) were used as research objects, the pigment and transcriptome of their petals during different flower development (stage S1, S2, S3, S4 and S5) were analyzed and compared. The results showed that the derivatives of cyanidin, peonidin and pelargonidin may be responsible for the pink of mutant petals and S2 stage (buds showing color at the top but with the scales still present) was the key stage of flower color formation of mutant. In total, 412,910 transcripts and 2,780 differentially expressed genes (DEGs) were identified in pairwise comparisons of WT and mutant petals. GO and KEGG enrichment analyses of the DEGs showed that the ‘DNA-binding transcription factor activity’, ‘Flavonoid biosynthesis’ and ‘Phenylpropanoid biosynthesis’ were more active in mutant petals. Early anthocyanin pathway candidate DEGs (CHS3-CHS6, CHI, F3Hs and F3’H) were strongly correlated and up-regulated expression in mutant petals than in WT petals at S2 stage. These genes may be the key structural genes for the pink coloration of mutant petals. In the petals of mutant, two R2R3-MYB unigene (TRINITY_DN59015_c3_g2 and TRINITY_DN49281_c1_g6) were identified as repressors involved in anthocyanin regulation and were significantly down-regulated at S2 stage. This study shed light on the biochemistry and genetic mechanisms underlying the flower coloration in two Rhododendron obtusum cultivars.

ALERGENE BILJKE NA TERITORIJI GRADA KRAGUJEVCA

The paper presents the quantitative and qualitative characteristics of allergenic plants in the urban area of the Kragujevac city. The ecological characteristics of these plants were determined through ecological index and life forms. During the conducted floristic study, the presence of 78 allergenic plants was determined. Half of the recorded allergenic plant species are woody ornamental plant species. Floristic analysis shows that the allergenic plants are from the Pinophyta and Magnoliophyta divisions from 19 families, most commonly conifers and grasses.

The value of alien representatives of Prunus L. genus for flowering cherries breeding

Aim. The necessity to search for sources and donors of deficit features for east cherry tree breeding (sakura) and to classify the collection of this promising woody ornamental plant for domestic horticulture determined the conduction of our research. Methods. The availability of some representatives of sakura collection of NDP «Sofiyivka» for breeding was studied with conventional methods, namely, flower color, intensity and duration of flowering, fruit attractiveness, form of a tree crown, vigor and other traits, which determine plant attractiveness for gardens, parks and street plantations, were estimated. Results. Among sakura cultivars which present interest for breeding and are characterized by high ornamental nature along with their adaptability to the conditions of most of the regions in Ukraine, such well-known cultivars as ‘Ama-no-gawa’, ‘Kanzan’, ‘Kiku-shidare-zakura’ and ‘Royal Burgundy’ are to be mentioned. Despite the information concerning the feasibility of spontaneous and the success of artificial intercultivar and interspecific hybridization of Prunus serrulata with other cultivars and other Prunus s. l. genera, at present we have not received P. serrulata hybrids. Conclusions. To enhance the breeding productivity of flowering cherry tree, namely hybridization efficiency of P. serrulata with donors and sources of ornamental traits, it is advisable to involve new initial material on a wide genetic basis not only by economic-valuable features, but also considering the cases of S-genes genetic incompatibility. Keywords: Amygdaloideae Arn., Prunus sensu lato, initial material for breeding, gametophytic self-incompatibility, oriental flowering cherries (sakura).

Mining Simple Sequence Repeat and Single Nucleotide Polymorphism Markers in a Transcriptomic Database of Wintersweet (Chimonanthus praecox)

Wintersweet is a woody ornamental plant and has a long history of human cultivation. Few molecular markers have been characterized and remain scant in wintersweet. This study aimed to mine simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) from the transcriptomic database of wintersweet. A total of 3972 SSRs and 97,060 putative SNPs/indels (92,307 SNPs and 4753 indels) were identified in this data set. This study marks the highest number of SSR and SNP markers discovered to date from wintersweet by using transcriptome sequencing data. These identified markers will provide a useful source for molecular genetic studies such as genetic diversity and characterization, association mapping, and map-based gene cloning in wintersweet.

Strategies to Control Loropetalum Decline in Central Florida

SL-255, a 5-page illustrated fact sheet by Amy L. Shober and Gary L. Leibee, describes this unexplained condition affecting the Ruby cultivar of this popular woody ornamental plant (also called Chinese fringebush or Chinese witch hazel) in central Florida. It presents the results of two studies conducted to identify possible causes and develop management methods. It includes suggested alternative cultivars and treatment recommendations for existing plantings. Published by the UF Department of Soil and Water Sciences, October 2007.