The genus Nymphaea in the Nymphaeaceae family comprises ∼50 species of aquatic plants. The plants in the genus commonly known as waterlily are categorized into two groups according to ecological characteristics: hardy waterlily and tropical waterlily (Henry 1905). Tropical waterlily consists of five subgenera: Confluentes, Hydrocallis, Lotos, Anecphya, and Brachyceras (Borsch et al. 2007; Sun et al. 2018). To create novel traits, breeders have achieved new cultivars by intersubgeneric hybridization. For example, Nymphaea ‘William Phillips’ was the first confirmed hybrid resulted from an intersubgeneric cross using N. colorata in subgenera Brachyceras as the male parent and N. gigantea in subgenera Anecphya as the female parent (Doran et al. 2004; Les et al. 2004). Subsequently, blue hardy waterlily was developed by intersubgeneric cross between subgenus Nymphaea and Brachyceras (Songpanich and Hongtrakul 2010).
Waterlilies have high ornamental value with showy flower color and are widely used for beautifying the environment (Huang et al. 2009). Breeding cultivars with novel flower color are always important targets for breeders. With the improvement in the economy and improved standard of living, single-color flowers cannot satisfy consumer demand. N. atrans, a member of subgenera Anecphya, possesses a unique phenotype in which flower color changes from its initial white to pink and finally red during florescence. The characteristic of flower color transition is rare and popular, which leads to high economic value. However, few waterlilies with flower color transition are available. In addition, reproduction speed is slow, and available seedlings cannot meet the market demand. Therefore, it is necessary to carry out a breeding program for developing more cultivars with flower color transition.
Many cross combinations have been designed; for example, a successful hybridization was obtained from N. atrans as the ovule parent and white-petals cultivar of N. colorata as the pollen parent. Here, we introduce and discuss Nymphaea ‘Guifei’.
Origin
The petals of N. atrans on the first day was pinkish white (RHS N155B), turning to pale purplish pink (RHS 65D) on the third day and finally vivid purple red (N57B) on the sixth day. The stamen is vivid yellow (RHS 9A) (Fig. 1). The white-petaled (RHS 157C) cultivar N. colorata was selected as the pollen parent for two reasons. First, previous reports indicated that seeds set successfully when crossed with members of subgenera Anecphya, which motivated us to make attempts at performing intersubgeneric cross (Les et al. 2004). Second, it introduces the possibility of generating genotypes with novel traits.
The flowers of N. atrans and N. ‘Guifei’. (S1) The first-day flower. (S2) The third-day flower. (S3) The sixth-day flower.
Citation: HortScience 59, 9; 10.21273/HORTSCI18046-24
In Oct 2016, a controlled cross was conducted in Haikou, China. The flower buds of male parent and the emasculated female parent were bagged to avoid insect pollination and self-fertilization. Artificial pollination was performed between 8:00 and 10:00 AM on sunny days. The stigmas were full of mucus when the flowers opened, the stigmatic fluid was collected in a glass using a dropper. The pollen from flowers blooming for 2 d were mixed with stigmatic fluid in the glass and added into the stigma disc of the female parent. The pollinated female flowers were marked and bagged again.
Approximately 80 seeds were harvested and sown in Dec 2016; only 16 seeds (20% seed germination rate) came up, and all the seedlings (100% survival) flowered in Apr 2017. A candidate individual plant with good flowering properties was selected in Jun 2017 and asexually reproduced using bulbs from Nov 2017 to Oct 2018. Thirty seedlings each were planted in Haikou (110°32′E, 20°00′N) and Danzhou (109°42′E, 19°35′N) in Nov 2018. The traits of flowers and leaves and plant habit were evaluated from 2019 to 2021 to ensure stability and uniformity. Finally, a promising cultivar was selected and named Guifei in Nov 2021 (Fig. 2); it was registered in Oct 2022 with the International Waterlily & Water Gardening Society (United States) and authorized by the Ministry of Agriculture and Rural Affairs of the Peoples’s Republic of China (No. CNA20221002655).
Description
The morphological characteristics of ‘Guifei’ were investigated according to the files applicated to register a Nymphaeaceae cultivar name appointed by the International Society for Horticultural Science and recorded for 15 randomly picked plants (three replicates × five plants) (Table 1). The colors of the plant organs were described according to the Royal Horticultural Society (RHS) Color Charts (2015).
Morphological features of the new cultivar Guifei.
Plant habit.
‘Guifei’ is a tuberous, perennial, aquatic herb. The plant diameter is ∼260 cm × 300 cm. The emergence height above water is 40 to 50 cm.
Leaves.
Leaf blades are orbicular-ovate, 42 to 45 cm long, and 40 to 42 cm wide. The adaxial leaf surface is yellow green (RHS 144A). The abaxial leaf surface is olive green (RHS 146A), suffused with grayed red (RHS 182B) toward the margins. Leaf margins are irregularly dentate with four to six teeth per 10 cm. The basal lobes are acute and overlap the sinus.
Flower.
Flowers are cup-shaped. Flower diameter is 13 to 15 cm. The four sepals are subcoriaceous and obovate. The top side of sepal is bluish white (RHS N155A), and the underside of the sepal is moderate brown (RHS 165A). There are 38 to 40 petals. The new cultivar inherits the characteristic of flower color transition of N. atrans (Fig. 1; Table 1). Its petals on the first day are partially violet (RHS 93A) and partially bluish white (RHS N155A), turning to deep purplish pink (RHS 68A) on the third day, and finally red purple (RHS N74A). Each flower lasts 6 to 7 d, which is a slightly longer flowering period than the 5 to 6 d of the N. atrans. There are ∼400 purple red stamens (RHS 186B).
‘Guifei’ is distinct from the female parent in its novel petal and stamen colors. In addition, the new cultivar exhibits a longer flowering period and strong resistance, and its petal texture is thick.
Cultivation
‘Guifei’ is a tropical waterlily and is continuously flowering in Hainan, China. The cultivation environment requires temperatures of 18 to 35 °C and full sunlight for growth. The plants should be kept submerged at a water depth of 50 to 80 cm of the pound, and the planting density is 250 cm by 350 cm. The reproductive mode is vegetatively propagated by the tubers.
Availability
‘Guifei’ is jointly owned by the Tropical Crops Genetic Resources Institute–Chinese Academy of Tropical Agricultural Sciences (Danzhou, China) and Hainan Fodu Lianyuan Ecological Agriculture Co. LTD (Haikou, China). Requests for research could contact Guangsui Yang (13976572870@163.com).
References Cited
Borsch T, Hilu KW, Wiersema JH, Löhne C, Barthlott W, Wilde V. 2007. Phylogeny of Nymphaea (Nymphaeaceae): Evidence from substitutions and microstructural changes in the chloroplast trnT-trnF region. Int J Plant Sci. 168(5):639–671. https://doi.org/10.1086/513476.
Doran AS, Les DH, Moody ML, Phillips WE. 2004. Nymphaea ‘William Phillips’, a new intersubgeneric hybrid. HortScience. 39(2):446–447. https://doi.org/10.21273/HORTSCI.39.2.446.
Henry SC. 1905. The waterlilies, p 125–211. The Carnegie Institution of Washington, Washington, DC, USA.
Huang GZ, Deng HQ, Li Z, Li G. 2009. Water lily (in Chinese). China Forestry Press, Beijing, China.
Les DH, Moody ML, Doran AS, Phillips WE. 2004. A genetically confirmed intersubgeneric hybrid in Nymphaea L. (Nymphaeaceae Salisb.). HortScience. 39(2):219–222. https://doi.org/10.21273/HORTSCI.39.2.219.
Songpanich P, Hongtrakul V. 2010. Intersubgeneric cross in Nymphaea spp. L. to develop a blue hardy waterlily. Sci Hort. 124(4):475–481. https://doi.org/10.1016/j.scienta.2010.01.024.
Sun CQ, Ma ZH, Zhang ZC, Sun GS, Dai ZL. 2018. Factors influencing cross barriers in interspecific hybridizations of Water lily. J Amer Soc Hort Sci. 143(2):130–135. https://doi.org/10.21273/JASHS04302-17.