Bougainvillea (Bougainvillea spp.) belongs to the family Nyctaginaceae and is a native to tropical regions of South America (Roy, 2019). It has many ornamental horticultural advantages, including superabundant and recurring blooms, bright and colorful bracts, strong stress tolerance, and easy propagation and maintenance. Bougainvillea is among the most popular ornamental landscaping and potted plants in tropical and subtropical areas (Roy, 2019).
Bougainvillea have a short history (≈150 years) of domestication and cultivation outside their natural habitats (Ohri, 2013; Zadoo et al., 1975). Breeding practices in the world have given rise to ≈500 varieties of bougainvillea differing in color, shape, and size of bracts. However, only less than 2% have polychromatic bracts, such as ‘Chitra’, ‘Wajid Ali Shah’, ‘Lipstick’, and ‘Imperial Delight’ (Datta et al., 2021; Sindhu et al., 2020). To meet growers’ needs for more cultivars in this group, we report a novel floriferous cultivar, Auspicious Cloud.
Origin
‘Auspicious Cloud’ is a triploid hybrid selected from a cross between ‘Galaxy’ (2×) and ‘Chitra’ (4×). ‘Galaxy’, serving as the female parent, is derived from a bud sport of ‘Mrs EVA White’ (white bracts). ‘Chitra’, a tetraploid hybrid with polychromatic bracts, served as the male parent (Roy, 2019) (Fig. 1). Artificial pollination was conducted in Jan. 2017 in the nursery of Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences (TCGRI-CATAS), Danzhou, China (lat. 19°35′N, long. 109°42′E). After 4 weeks, seeds were harvested and sown in peat. In January 2018, the seedling B1906-3 was selected and propagated asexually by cuttings. Various attributes including growth and flower characteristics were evaluated from 2018 to 2020. The confirmation of ‘B1906-3’ as a triploid hybrid was conducted through chromosome counting (Fig. 2C) and flow cytometry (Fig. 2D–F). And then, ‘B1906-3’ was then selected as a promising cultivar and designated as ‘Auspicious Cloud’ (Fig. 2A).
Pedigree and timeline of breeding procedures used in the development of Bougainvillea ‘Auspicious Cloud’.
Citation: HortScience 57, 7; 10.21273/HORTSCI16609-22
The phenotypic characteristics and cytological ploidy of Bougainvillea ‘Auspicious Cloud’. (A) Potted ‘Auspicious Cloud’. (B) The bracts of ‘Auspicious Cloud’ and its polychromatic parent ‘Chitra’. (C) Chromosome microscopy of ‘Auspicious Cloud’ (2n = 51). (D–F) Flow cytometry histograms of nuclei isolated from cultivars with different ploidy levels, (D) diploid ‘Galaxy’, (E) triploid ‘Auspicious Cloud’, and (F) tetraploid ‘Chitra’. The known diploid ‘Galaxy’ (2n = 2x = 34) was used as reference for evaluating.
Citation: HortScience 57, 7; 10.21273/HORTSCI16609-22
Description and Performance
Morphological characteristics were described according “Protocol for Tests on Distinctness, Uniformity and Stability-Bougainvillea Comm. ex Juss (CPVO-TP/267/1)” (International Union for the Protection of New Varieties of Plants, 2014). Observations and measurements were conducted repeatedly on 30 plant samples grown under PVC greenhouse, at 12, 24, and 36 months after transplanting.
Plant habit.
‘Auspicious Cloud’ is a perennial shrub. Compared with its dwarf parent ‘Galaxy’ and tall parent ‘Chitra’, it has a compact plant type and medium branching ability.
Branches.
The young branches are green, and the mature branches after lignification are brown (Fig. 2A).
Thorns.
The young thorns are green and turn into light brown, long (2.2 cm on average), hard, and slightly curved after lignification.
Leaves.
‘Auspicious Cloud’ has a medium-sized ovate leaves that are 6.2 cm in length and 4.9 cm in width on average (Table 1). The petioles have an average length of 1.1 cm. Juvenile leaves are yellow-green and turn dark green (adaxial surface 15th RHS 139A, abaxial surface RHS 138A) when they mature.
Performance of Bougainvillea ‘Auspicious Cloud’ in Danzhou, Hainan, China.
Flowers.
The arrangement of inflorescence on the branches was axillary. Flowers arranged in a three-flowered inflorescence with showy bracts. Floral tube is opening upward and 2.3 cm in length. The number of sepals per flower is five. The flowers are not persistent after flowering.
Flower bracts.
At immature stage, the bracts contain irregular blotches of gold (RHS 7B), yellowish white (RHS 115C), and moderate reddish orange (RHS N34), whereas mature bracts are a combination of vivid red (RHS 46C), bright pinks (RHS 52B), and creamy white (NN155C), combining to quite the spectacle (Fig. 2A and B). The bracts are broadly ovoid, blunt tipped, cordate at the base, wavy at the edge, and open outward. The size of mature bracts is larger (length = 5.9 cm, width = 4.9 cm) than its parents and common cultivars.
‘Auspicious Cloud’ is easily propagated through hardwood stem cuttings (0.75 to 1.5 cm in diameter). The cuttings are rooted in a well-prepared bed (soil: sand = 1:1) and covered with clear plastic sheet for 6 weeks. No specific susceptibility to pathogens or pests was observed under growing conditions for 3 consecutive years.
In summary, the most distinguishing characteristics of ‘Auspicious Cloud’ are as follows: 1) larger bracts than its parents and most existing cultivars, 2) multicolored and beautiful bracts, and 3) vigorous growth as a triploid hybrid. These characteristics make it unique, and it promises to be a popular potted and landscaping cultivar.
Availability
‘Auspicious Cloud’ has been propagated by the nursery of TCGRI-CATAS in Hainan, China. Plants for research purposes may be obtained directly from the author (niujunhai2014@sina.com).
Literature Cited
Datta, S.K., Jayanthi, R. & Janakiram, T. 2021 Bougainvillea 141 174 Datta, S.K. & Gupta, Y.C. Floriculture and ornamental plants. Handbooks of crop diversity: Conservation and use of plant genetic resources Springer Singapore https://doi.org/10.1007/978-981-15-1554-5_2-1
International Union for the Protection of New Varieties of Plants 2014 Protocol for distinctness, uniformity and stability—Bougainvillea Comm. ex Juss (CPVO-TG/267/1) http://cpvo.europa.eu/sites/default/files/documents/bougain-villea.pdf
Ohri, D. 2013 Cytogenetics of domestication and improvement of garden gladiolus and bougainvillea Nucleus 56 149 153 https://doi.org/10.1007/s13237-013-0091-7
Roy, R.K. 2019 Bougainvillea—A color handbook Astral International Pvt. Ltd New Delhi, India 161
Sindhu, S.S., Singh, B. & Saxena, N.K. 2020 Genetic improvement of bougainvillea in Indian scenario—A review J. Ornam. Hort. 23 1 1 11 https://doi.org/10.5958/2249-880X.2020.00001.8
Zadoo, S.N., Roy, R.P. & Khoshoo, T.N. 1975 Cytogenetics of cultivated Bougainvilleas. V. Induced tetraploidy and restoration of fertility in sterile cultivars Euphytica 24 517 524 https://doi.org/10.1007/BF00028222
