Breeding for new phalaenopsis varieties has been conducted for many decades. With the efforts of breeders, a lot of varieties have been bred and sold in the market, including many colorful varieties with various flower sizes. However, new varieties are constantly being bred and selected every year and are expected to create new colors or new types that are different from those on the market. Breeding for indigo flowers has been a common goal for many breeders in the world. Currently, indigo Phalaenopsis is rarely seen on the commercial market. Most of them are crossed or backcrossed from certain species or commercial varieties such as Phal. equestris, Phal. pulcherrima, Phal. violacea, Phal. Kenneth Schubert, and Phal. Purple Martin, and only a few native blue species have been applied to blue Phalaenopsis hybridization (Tsao et al., 2020). Blue flowers of most plants are the result of delphinidin accumulation or expression (Qingyu and Silan, 2004), and in only a few cases (such as Phalaenopsis) is the blue color a result of cyaniding in flowers (Tatsuzawa et al., 2004). Blue flowers of most Phalaenopsis varieties faded easily without delphinidin expression as a result of the lack of the flavonoid 3',5'-hydroxylase gene. It is necessary to introduce other genes to the Phalaenopsis genus by crossing with other genera or by transferring a gene or genes from other genera to create unique flower colors or characteristics. In our study, we introduced a stable blue color to Phalaenopsis from the genus Rhynchostylis to breed Rhynchonopsis Tariflor Blue Kid ‘1030-4’ successfully with a deep and nonfading blue color.
Origin
Rhynchonopsis Tariflor Blue Kid ‘1030-4’.
All the breeding, including crossing, selection, and performance studies, was carried out under natural greenhouse conditions at the Floriculture Research Center. Flowering plants of Phal. Fire Cracker and Rhynchostylis coelestis were grown in a pad and fan greenhouse. Phal. Fire Cracker was used as the seed parent that was crossed with Rhy. coelestis in Aug. 2007. Mature capsules were surface-sterilized with 70% ethanol, followed by 1.0% sodium hypochlorite solution for 20 min and rinsed three times with sterile distilled water. Capsules were cut open and the seeds were scooped out with forceps onto Murashige and Skoog medium that had half-strength macroelements and full-strength microelements (Murashige and Skoog, 1962) supplemented with 100 mg⋅L–1 myo-inositol, 0.5 mg⋅L–1 niacin, 0.5 mg⋅L–1 pyridoxine hydrogen chloride, 0.1 mg⋅L–1 thiamine hydrogen chloride, 2.0 mg⋅L–1 glycine, 20,000 mg⋅L–1 sucrose, 7000 mg⋅L–1 Difco Bacto agar, and 1000 mg⋅L–1 activated charcoal. The pH of the medium was adjusted to 5.7 before autoclaving at 121 °C, 1.05 kg⋅cm–2 for 20 min. The seeds were incubated at 25 ± 1 °C under a 14-h photoperiod at an irradiance of 40 μmol⋅m–2⋅s–1 (daylight cool-white fluorescent light). Two hundred ninety-seven seedlings from flasks were grown in sphagnum moss under natural greenhouse conditions (20 to 30 °C, 12–13.5-h daylength). Irrigation was performed once every 1 to 2 weeks during the cultivation period. Peters 20N–20P2O5–20K2O at 1.0 g⋅L–1 (Scotts Company, Marysville, OH) was added to tap water as the fertilizer solution. Seedling plants flowered in July 2010, and this hybrid was registered as Rhnps. Tariflor Blue Kid. The cultivar ‘1030-4’ was selected from more than 100 seedlings because of its darker blue flowers in July 2010. After that, the stalk was used to be propagated by tissue culture.
Description and Performance
Rhnps. Tariflor Blue Kid ‘1030-4’ was bred and selected by crossing Phal. Fire Cracker with Rhy. coelestis. The characteristics of new cultivar are similar to those of Phalaenopsis. Phal. Freed’s Beautiful Girl was used as the control variety and is compared to the new line. Rhnps. Tariflor Blue Kid ‘1030-4’ had 24 traits that distinguish it from Phal. Freed’s Beautiful Girl (Table 1) based on the distinctness, uniformity, and stability (DUS) test guideline for Phalaenopsis (International Union for the Protection of New Varieties of Plants, 2013). DUS testing is a way of judging whether a new variety differs from existing varieties within the same species (the distinctness part), whether the characteristics used to establish distinctness are expressed uniformly (the uniformity part), and whether these characteristics change (or not) through subsequent generations (the stability part) (An et al., 2014). The following color description was based on The Royal Horticultural Society’s (RHS) color chart (Royal Horticultural Society, 2015). Plants of Rhnps. Tariflor Blue Kid ‘1030-4’ are of medium size, with oval leaves, spots on the upper side of leaves, and darker green leaves. Plants of Phal. Freed’s Beautiful Girl are large, with oval leaves, no spots on the upper side of leaves, and lighter green leaves. Rhnps. Tariflor Blue Kid ‘1030-4’ has a greater average flower count (n = 15) than that of Phal. Freed’s Beautiful Girl (n = 8). The flower diameter of Rhnps. Tariflor Blue Kid ‘1030-4’ and Phal. Freed’s Beautiful Girl is 3.5 cm and 5 cm, respectively (Fig. 1). The dorsal sepal of Rhnps. Tariflor Blue Kid ‘1030-4’ and Phal. Freed’s Beautiful Girl is moderately compressed and moderately elongated, respectively. The cross section of the dorsal sepal for Rhnps. Tariflor Blue Kid ‘1030-4’ is concave, and the ground color of the upper side is moderate violet (RHS 86A). The cross section of the dorsal sepal for Phal. Freed’s Beautiful Girl is straight, and the ground color of the upper side is strong purple (RHS N82A). The ground color of the upper side for the lateral sepal of Rhnps. Tariflor Blue Kid ‘1030-4’ and Phal. Freed’s Beautiful Girl is strong purple (RHS N87A) and strong purple (RHS N82A), respectively. The cross section of the petal for Rhnps. Tariflor Blue Kid ‘10304’ is concave, and the ground color of the upper side is strong purple (RHS N82B). The cross section of the petal for Phal. Freed’s Beautiful Girl is straight, and the ground color of the upper side is strong purple (RHS N87A). The size of the lateral lobe relative to the apical lobe for Rhnps. Tariflor Blue Kid ‘1030-4’ is equal and large for Phal. Freed’s Beautiful Girl, respectively. Lip traits of Rhnps. Tariflor Blue Kid ‘1030-4’ are as follows: ground color, tip color, and spot color of the lip apical lobe are very pale violet (RHS 91D), moderate violet (RHS 86A), and moderate violet (RHS 86A) respectively. Lip traits of Phal. Freed’s Beautiful Girl are as follows: ground color, tip color, and spot color of the lip apical lobe are very pale purple (RHS 85D), strong purple (RHS 87A), and deep purple(RHS 83B), respectively. The callus color of Rhnps. Tariflor Blue Kid ‘1030-4’ is very pale violet (RHS 91D) with spots, whereas the callus color of Phal. Freed’s Beautiful Girl is brilliant yellow (RHS 12B) without spots. The apex color of the column of Rhnps. Tariflor Blue Kid ‘1030-4’ and Phal. Freed’s Beautiful Girl is strong purple (RHS N82A) and strong purple (RHS N87B), respectively.
Comparisons of Rhnps. Tariflor Blue Kid ‘1030-4’ and Phal. Freed’s Beautiful Girl plant, leaf, and flower based on the distinctness, uniformity, and stability (DUS) test guideline of Phalaenopsis.
Flower of Rhnps. Tariflor Blue Kid ‘1030-4’ (left) and Phal. Freed’s Beautiful Girl (right).
Citation: HortScience 57, 3; 10.21273/HORTSCI15944-21
Availability
Questions concerning Rhynchonopsis Tariflor Blue Kid ‘1030-4’ and the research should be addressed to Dr. Jung-Yi Wu (E-mail: iris12@tari.gov.tw) at the Floriculture Research Center, Taiwan Agriculture Research Institute, Council of Agriculture, Taiwan.
Literature Cited
An, C.H., Liu, M.C., Liu, Z.H. & Kuo, L.T. 2014 Amendment of test guidelines for the new cultivars of Phalaenopsis Seed Nursery (Taiwan) 16 49 69
International Union for the Protection of New Varieties of Plants 2013 TG/213/2 test guidelines of Phalaenopsis International Union for the Protection of New Varieties of Plants Geneva, Switzerland
Murashige, T. & Skoog, F. 1962 A revised medium for rapid growth and bioassays with tobacco tissue culture Physiol. Plant. 15 473 497 https://doi.org/10.1111/j.1399-3054.1962.tb08052.x
Qingyu, X. & Silan, D. 2004 Blue flowers’ molecular breeding Mol. Plant Breed. 2 1 93 99
Royal Horticultural Society 2015 The Royal Horticultural Society’s color chart 5th ed. Royal Horticultural Society London, UK
Tatsuzawa, F., Saito, N., Seki, H., Yokoi, M., Yukawa, T., Shinoda, K. & Honda, T. 2004 Acylated anthocyanins in the flowers of Vanda (Orchidaceae) Biochem. Syst. Ecol. 32 651 664 https://doi.org/10.1016/j.bse.2004.02.004
Tsao, C.Y., Chen, U.C., Wu, R.Y., Wu, T.Y. & Hsia, C.N. 2020 Polyploidization and selection of parents for improving breeding of blue-purple Phalaenopsis J. Taiwan Agr. Res. 69 154 168 https://doi.org/10.6156/JTAR.202006_69(2).0005
