Orchid Cultivars Research Articles

Orchid2024: A cultivar-level dataset and methodology for fine-grained classification of Chinese Cymbidium Orchids

BackgroundChinese Cymbidium orchids, cherished for their deep-rooted cultural significance and significant economic value in China, have spawned a rich tapestry of cultivars. However, these orchid cultivars are facing challenges from insufficient cultivation practices and antiquated techniques, including cultivar misclassification, complex identification, and the proliferation of counterfeit products. Current commercial techniques and academic research primarily emphasize species identification of orchids, rather than delving into that of orchid cultivars within species.ResultsTo bridge this gap, the authors dedicated over a year to collecting a cultivar image dataset for Chinese Cymbidium orchids named Orchid2024. This dataset contains over 150,000 images spanning 1,275 different categories, involving visits to 20 cities across 12 provincial administrative regions in China to gather pertinent data. Subsequently, we introduced various visual parameter-efficient fine-tuning (PEFT) methods to expedite model development, achieving the highest top-1 accuracy of 86.14% and top-5 accuracy of 95.44%.ConclusionExperimental results demonstrate the complexity of the dataset while highlighting the considerable promise of PEFT methods within flower image classification. We believe that our work not only provides a practical tool for orchid researchers, growers and market participants, but also provides a unique and valuable resource for further exploring fine-grained image classification tasks. The dataset and code are available at https://github.com/pengyingshu/Orchid2024.

Genetic profiles and phenotypic patterns in Taiwanese Phalaenopsis orchids: a two-step phenotype and genotype strategy using modified genetic distance algorithms.

This study establishes the first core collection (CC) for Taiwanese Phalaenopsis orchids to preserve genetic diversity and key traits essential for breeding and research, thereby enhancing breeding efficiency without the need for a large maintained parent population. We examined 207 commercial orchid cultivars from ten nurseries, characterized by two phenotypes and genotypic data from eight simple sequence repeat markers. Multiple imputation was applied to estimate missing phenotypes, minimizing potential uncertainties and ensuring the reliability of population structure analysis. Weighted k-means clustering identified seven distinct clusters, highlighting substantial genetic diversity. We proposed a two-step phenotype and genotype strategy and modified genetic distance algorithms to effectively preserve both phenotypic and genetic diversity while retaining key features. Consequently, 22 core accessions were selected, distributed across seven clusters, and representing the orchid germplasm collection. Our evaluation revealed significant diversity preservation, particularly in distinct characteristics and rare features, outperforming other methodologies. Pedigree background analysis further confirmed the representativeness of the CC in maintaining diverse genetic materials. We emphasized the importance of evaluating the CC by detailing the criteria and statistical analyses used to ensure the quality, representativeness, and effectiveness of the selected accessions. This study contributes to orchid breeding, conservation efforts, and sustainable agricultural practices by providing a valuable and comprehensive resource. In conclusion, our research establishes a groundbreaking CC, offering insights into the genetic landscape of Taiwanese Phalaenopsis orchids and highlighting potential advancements in breeding commercially desirable varieties.

New Insights into the Mechanism of Spatiotemporal Scent Accumulation in Orchid Flowers.

Orchid flowers have a unique structure that consists of three sepals and three petals, with one of the petals forming the labellum (lip) that can be differentiated into the hypochile and epichile. In orchids, the emission of floral scent is specific and spatially complex. Little is understood about the molecular and biochemical mechanisms of the differing scent emissions between the parts of orchid flowers. Here, we investigated this in the Cattleya hybrid KOVA, and our study showed that monoterpenes, including linalool and geraniol, are the main components responsible for the KOVA floral scent. The KOVA flower was scentless to the human nose before it reached full bloom, potentially because the 1-deoxy-d-xylulose 5-phosphate synthases (RcDXSs) and 4-hydroxy-3-methylbut-2-enyl diphosphate synthases (RcHDSs) that biosynthesize monoterpenes were highly expressed in flowers only when it reached full flowering. Additionally, the spatial expression profile of the monoterpene synthases (RcMTPSs), which were highly expressed in the basal region of the lip (hypochile), contributed to the highest monoterpene emissions from this part of the flower. This might have caused the hypochile to be more fragrant than the other parts of the flower. These findings enrich our understanding of the difference in scents between different flower parts in plants and provide information to breed novel orchid cultivars with special floral scents.

Gamma Radiation Induced In-Vitro Mutagenesis and Isolation of Mutants for Early Flowering and Phytomorphological Variations in Dendrobium 'Emma White'.

In vitro mutagenesis offers a feasible approach for developing new orchid cultivars through genetic manipulation. In the present study, protocorm-like bodies (PLBs) were exposed to gamma rays (10, 20, 40, 60, 80 Gy) to study in vitro growth responses and induction of mutants in Dendrobium 'Emma White'. Both proliferation and regeneration of PLBs decreased progressively with increasing doses, except for a significantly enhanced growth response at 10 Gy. The optimal dose of gamma radiation for mutagenesis was found in the range 10 to 25 Gy based on the growth reduction curve. Analysis using a high-throughput cell analyzer revealed a significant reduction in nuclear DNA content at > 40 Gy doses. At 10 Gy treatment, the growth attributes, such as root length, plant height and leaf number, were significantly increased by 36%, 26% and 20%, respectively, compared to the control. This increase was significant over other tested doses as well. Testing of random amplified polymorphic DNA markers revealed the presence of detectable polymorphism among gamma mutant plantlets with a polymorphism information content value at 0.41. The gamma-ray-induced earliness in flower development was observed within 294 days post ex vitro growth of 10 Gy mutant compared to the control plants flowered after 959 days. Our results highlight the significance of gamma radiation in inducing enhanced growth, morphological variations and early floral initiation in Dendrobium, providing a basic framework for mutation breeding and improvement of orchids.

In-depth analysis of genomes and functional genomics of orchid using cutting-edge high-throughput sequencing.

High-throughput sequencing technology has been facilitated the development of new methodologies and approaches for studying the origin and evolution of plant genomes and subgenomes, population domestication, and functional genomics. Orchids have tens of thousands of members in nature. Many of them have promising application potential in the extension and conservation of the ecological chain, the horticultural use of ornamental blossoms, and the utilization of botanical medicines. However, a large-scale gene knockout mutant library and a sophisticated genetic transformation system are still lacking in the improvement of orchid germplasm resources. New gene editing tools, such as the favored CRISPR-Cas9 or some base editors, have not yet been widely applied in orchids. In addition to a large variety of orchid cultivars, the high-precision, high-throughput genome sequencing technology is also required for the mining of trait-related functional genes. Nowadays, the focus of orchid genomics research has been directed to the origin and classification of species, genome evolution and deletion, gene duplication and chromosomal polyploidy, and flower morphogenesis-related regulation. Here, the progressing achieved in orchid molecular biology and genomics over the past few decades have been discussed, including the evolution of genome size and polyploidization. The frequent incorporation of LTR retrotransposons play important role in the expansion and structural variation of the orchid genome. The large-scale gene duplication event of the nuclear genome generated plenty of recently tandem duplicated genes, which drove the evolution and functional divergency of new genes. The evolution and loss of the plastid genome, which mostly affected genes related to photosynthesis and autotrophy, demonstrated that orchids have experienced more separate transitions to heterotrophy than any other terrestrial plant. Moreover, large-scale resequencing provide useful SNP markers for constructing genetic maps, which will facilitate the breeding of novel orchid varieties. The significance of high-throughput sequencing and gene editing technologies in the identification and molecular breeding of the trait-related genes in orchids provides us with a representative trait-improving gene as well as some mechanisms worthy of further investigation. In addition, gene editing has promise for the improvement of orchid genetic transformation and the investigation of gene function. This knowledge may provide a scientific reference and theoretical basis for orchid genome studies.

Breakthroughs the in developing of new orchid cultivars

Breakthroughs the in developing of new orchid cultivars

Tulasnella calospora (UAMH 9824) retains its effectiveness at facilitating orchid symbiotic germination in vitro after two decades of subculturing

BackgroundThe technique of symbiotic germination—using mycorrhizal fungi to propagate orchids from seed in vitro—has been used as one method to cultivate orchids in North America and abroad for > 30 years. A long-held assumption is that mycorrhizal fungi used for this purpose lose their effectiveness at germinating seeds over time with repeated subculturing.ResultsWe provide evidence for the lingering efficacy of one particular strain of Tulasnella calospora (266; UAMH 9824) to stimulate seed germination exemplified by the North American terrestrial orchid, Spiranthes cernua, as a case study. This fungus was originally acquired from roots from Spiranthes brevilabris in 1999 and sub-cultured during the two decades since. Seeds inoculated with the fungus in vitro developed to an advanced protocorm stage after 16 days, and leaf elongation was pronounced after 42 days. In a pilot study, seedlings co-cultured with Tulasnella calospora 266 were deflasked after 331 days and later transferred to soil under greenhouse conditions where they eventually initiated anthesis. During the course of two decades, seeds of 39 orchid species, cultivars and hybrids spanning 21 genera, germinated in vitro co-cultured with Tulasnella calospora 266. These orchids included temperate terrestrials and tropical epiphytes alike.ConclusionsThe sustained effectiveness of this fungus is noteworthy because it argues against the concept of mycorrhizal fungi losing their symbiotic capability through prolonged subculturing. This study serves as an example of why in situ habitat preservation is essential for the conservation of orchids as a source of potentially useful mycorrhizal fungi.

Effects of genetic, explant type, plant growth regulator and culture medium on in vitro regeneration of commercial Phalaenopsis orchid cultivars

Effects of genetic, explant type, plant growth regulator and culture medium on in vitro regeneration of commercial Phalaenopsis orchid cultivars

Colchicine-induced tetraploidy in Dendrobium cariniferum and its effect on plantlet morphology, anatomy and genome size

Dendrobium cariniferum Rchb. f. is an important crossing parent that is primarily used to produce aromatic Dendrobium orchid cultivars due to its beautiful flowers and pleasant orange fragrance. However, there are no offspring within the limited progenies that fully inherit this odor trait. Thus, converting diploid D. cariniferum into tetraploids for interploid hybridization is another promising approach to creating a new orange aroma germplasm. This study reports a novel in vitro colchicine-induced chromosome doubling protocol that would effectively convert diploid D. cariniferum protocorms into tetraploids. A total of 120 tetraploid genotypes were identified by flow cytometry. The tetraploid induction rate was significantly affected by interaction between the colchicine concentration and exposure time. Treatment with 0.05% colchicine for 24 h produced the optimal results, yielding 54% surviving regenerated plantlets with a 33% tetraploid induction rate. The tetraploid plantlets displayed obvious morphological variations (broader, thicker leaves and greater stem and root diameters) than the diploid plantlets. Tetraploidization also caused a significant change in the leaf anatomical structure, including larger stomata with lower densities, more chloroplasts per stomata, thicker spongy tissues, larger leaf veins and decreased adaxial epidermal cell and trichome densities. We were the first to observe that there are one to five branched trichomes in the leaf sheath in both diploids and tetraploids, and we propose that the leaf adaxial epidermal cell density can be used to identify tetraploids. Moreover, tetraploids exhibited a 1.75-fold greater genome size than diploids. Our study lays the foundation for breeding triploid aromatic Dendrobium orchids. Autotetraploidy causes morphological, anatomical and genome size variations. This is the first report of trichome types in the leaf sheath. Leaf adaxial epidermal cell density is useful for identifying tetraploids.

Variability in the response to ethylene of cut flowers of threeVandaorchid cultivars

Variability in the response to ethylene of cut flowers of three<i>Vanda</i>orchid cultivars

Taxonomic Treatment of Chimeras in Orchids

Leaf variegation is a well-known illustration of chimerism in plants, resulting from heterogeneity of genetic material within the shoot apical meristems. The occurrence and manifestation of chimeras in the family Orchidaceae is poorly understood. Therefore, the aims of the present study were to analyze the chimeric phenotype of variegated leaves in wild European orchids and to discuss the taxonomic rank of chimeras. We document the presence of periclinal-mericlinal chimeras in Epipactis purpurata and Cephalanthera damasonium, and discuss the variegated phenotypes in the context of the shoot apical meristem activity. Descriptions of chimeric orchids refer mostly to cultivars and only rarely to wild plants, in which the taxonomic rank of chimeras is uncertain, and not discussed in the literature. Lack of precise rules in the International Code of Nomenclature for algae, fungi and plants results in randomness in chimera categorization and taxonomy. In this article, using orchids as our case study, we discuss the problem of chimeras' taxonomic status. Orchid cultivars and in particular their nomenclature are neither studied nor discussed here.

Breeding of a Fragrant, Mini-multiflora &lt;i&gt;Phalaenopsis&lt;/i&gt; Hybrid Orchid Cultivar, ‘Bravo Star’

Phalaenopsis ‘Bravo Star’, a new orchid cultivar, is both fragrant and has a multi-branch architecture with miniature, pink flowers. It was derived from a cross made by Gyeongnam Agricultural Research and Extension Service in 2016 of ‘Kung’s Red Coral’ (female) to ‘Tzu Chiang balm’ (male). To produce the hybrid, five F1 lines having strong fragrance and multiple flowering characters were selected from 2010 to 2012. A line then referred to as ‘08–VIO-16’ was finally selected after confirmation of stability and uniformity characteristics through evaluation and testing during 2013–2015. The selection ‘08-VIO-16’ was described as having a flat flower form and dark pink (RPN 57B) petal and sepal as well as a 29.1 cm flower stalk length. It had a flat and narrow obovate leaf form. The average leaf length and width were 18.2 and 6.5 cm, respectively. The average flower length and width were 5.7 and 5.2 cm, respectively. Although t his selection had a relatively low f lower number of 7.8 flowers per stalk, it was determined to be a good candidate cultivar for the potted plant market during evaluation and exhibition due to its multi-branching and inflorescence shape as well as its strong, sweet scent that is similar to cinnamon fragrance. Furthermore, it was found to be relatively easy to propagate in vitro and had a vigorous and fast growing habit. Following evaluation, this selection was registered as hybrid cultivar ‘Bravo Star’ on March 2017 (registration no. 6719) and protected by the seed industry act.

Breeding of a fragrant, multiflora Phalaenopsis by Neofinetia intergeneric hybrid orchid cultivar, ‘Pinky Beauty’

The Chungcheongbuk-do Agricultural Research and Extension Service has developed a new intergenic hybrid orchid cultivar released under the name ‘Pinky Beauty.’ The marketable qualities of this new cultivar include an abundance of flowers, a good fragrance, and a relatively long flowering period. It was derived from an initial intergeneric cross between (Phalaenopsis pulcherrima x P. parishii ) x Neofinetia falcata ‘Hwacheon’ in 2007. The seed germination, cultivation, selection, and characteristic evaluation trials were conducted from 2008 to 2014. After selecting a line that grew well and had desirably shaped and colored flowers, its morphological characteristics were investigated, from 2015 to 2017, according to the survey standard for agricultural experimentation and research that is used for the evaluation of new N. falcata varieties. The selection had pink flowers, which were determined to be Red-purple Group 68D based on the RHS color chart, on a dark green stem. The length of the flower stem was measured on average to be 25.8 cm, and the number of flowers per stem was 16.3. The width of a typical flower was about 2.5 cm, and the flowers had a short spur similar to N. falcata on the back of the lip. The plant height was on average 12.7 cm, which is similar to the control cultivar P. pulcherrima, while the leaf width was 1.6 cm. The overall volume of the flower pot was high. The flowering time of the hybrid was in late May, and its flowering period was about 34 days. Furthermore, it had a noticeably pleasant scent. Due to this desirable combination of characteristics, the selection was released as the cultivar ‘Pinky Beauty’ in 2018.

Comparative transcriptome analysis provides global insight into gene expression differences between two orchid cultivars.

The orchids GL and YL are two cultivars of Cymbidium longibracteatum. YL displays an obviously yellowing rhizome and yellow leaves, while GL ('Longchangsu') shows dark green leaves and greenish rhizome. But the molecular mechanism for the differences between the two cultivars is poorly understood. In the present study, we showed that the structure of chloroplasts was significantly damaged in YL. Biochemical analysis uncovered the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid were notably decreased in YL. Using RNA-Seq technology, more than 38 million clean reads were generated in each pool, and 116,422 unigenes were assembled de novo. 6,660 unigenes with differential expression patterns (FDR≤0.01 and |log2 ratio|≥1) were totally identified between the two cultivars. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed unigenes (DEGs) suggested 33 KEGG pathways were notably enriched, including biological processes such as “phenylpropanoid biosynthesis”, “phagosome”, “starch and sucrose metabolism”, “drug metabolism—cytochrome P450”, “fatty acid elongation”, and “flavone and flavonol biosynthesis”. Further analysis revealed that chlorophyll degeneration related unigene (c48794_g1) and flavonoid biosynthesis related unigenes (c16388_g1, c48963_g1, c63571_g1, c4492_g1, c52282_g1, c78740_g1, c4645_g1) were up-regulated while carotenoid biosynthesis related unigene (c7212_g1) were down-regulated in YL. Additionally, six of NAC, R2R3-MYB, bHLH transcription factors (c42861_g1, c105949_g1, c61265_g1, c42659_g1, c82171_g1, c19158_g1) might be involved in regulation of pigment biosynthesis. The chlorophyll degeneration and the flavonoid biosynthesis related unigenes up-regulation together with the carotenoid biosynthesis related unigenes down-regulation may contribute to the yellowing phenotype of YL.

The Greenish Flower Phenotype of Habenaria radiata (Orchidaceae) Is Caused by a Mutation in the SEPALLATA-Like MADS-Box Gene HrSEP-1.

In Arabidopsis thaliana, the E-class SEPALLATA (SEP) genes are generally expressed across all floral whorls. These genes play fundamental roles in floral organ fate determination during development by interacting with other MADS-box gene products, such as those from A-, B-, and C-class genes. However, the function of SEP genes in orchid remains obscure. Here, we analyzed a mutant orchid cultivar with greenish flowers in Habenaria radiata and found that this phenotype is caused by the absence of SEP function. Wild type H. radiata flowers contain a column and two perianth whorls consisting of three greenish sepals, two white petals, and a lip (labellum). By contrast, the flowers of H. radiata cultivar ‘Ryokusei’ appear greenish, with three normal sepals in whorl 1, two greenish petals and a lip in whorl 2, and several sepaloid organs and a ventral column in whorls 3 and 4. We isolated two SEP-like genes (HrSEP-1 and HrSEP-2) and two AGAMOUS-like genes (HrAG-1 and HrAG-2) from wild type H. radiata and compared their expression in the wild type vs. the mutant cultivar. HrAG-1 and HrAG-2 were expressed in the column in the wild type, whereas these genes were expressed in the ventral column and in sepaloid organs that had been converted from a column in ‘Ryokusei.’ HrSEP-1 and HrSEP-2 were expressed in all floral organs in the wild type. However, in the mutant cultivar, HrSEP-2 was expressed in all floral organs, while HrSEP-1 expression was not detected. Thus, we analyzed the genomic structures of HrSEP-1 in the wild type and ‘Ryokusei’ and identified a retrotransposon-like element in its first exon in ‘Ryokusei.’ Yeast two-hybrid assays demonstrated that HrSEP-1 interacts with HrDEF, HrAG-1, and HrAG-2. These results indicate that the mutant phenotype of ‘Ryokusei’ flowers is caused by the loss of function of HrSEP-1. Therefore, this gene plays an important role in column, lip, and petal development in H. radiata flowers.

Nutrient management in orchids: A review

Orchids are one of the most important flower crops in the world market due to its wide variability and good vase life. Orchids are similar to other non orchidaceous plants in their requirements for nutrients except that they generally take a longer time to exhibit nutrient deficiency. The rate of mineral uptake by orchid roots is lower when compared to other crop plants. NPK level of 1:6:1 favors the vegetative growth and 2:6:1 favors reproductive growth in orchid cultivar Sonia-17. 100 mg/l K is recommended for optimum vegetative and reproductive development of Dendrobium c.v Red Emperor ‘Prince’. The total N content in orchids varies from 0.11–0.28%, P content (0.11–0.28%), K content (0.57–0.42%), Ca content (2.1–3.66%), Mg content (1.1–3.0%) and tropical Sulphur content varied from 1–2.3%. Organic spray of 1% Vermiwash at 4 days interval also produces good quality flowers. Spray solution the concentration of 180:135:90 NPK is suitable for the growth and development of Mokara c.v Diehard Red and Dendrobium c.v Red Bull.

Potential Use of Plant Waste from the Moth Orchid (Phalaenopsis Sogo Yukidian "V3") as an Antioxidant Source.

This research was conducted to exploit the waste of used plant parts from the widely marketed moth orchid cultivar (Phalaenopsis Sogo Yukidian “V3”). Various extracts of roots, stems, and leaves were evaluated for total phenolics, total flavonoids, and antioxidant capacity. The bound extract from stems contained the highest total phenolics (5.092 ± 0.739 mg GAE (gallic acid equivalent)/g DW (dry weight)). The maximum total flavonoids (2.218 ± 0.021 mg RE (rutin equivalent)/g DW) were found in the hexane extract of leaves. Ethyl acetate extract from roots showed the greatest antioxidant activity compared to other extracts. Of these extracts, the IC50 values of these samples were 0.070 mg/mL, and 0.450 mg/mL in a free radical 1,-diphenyl-picryl-hydrazyl (DPPH) assay and reducing power method, respectively. The lipid peroxidation inhibition (LPI) was found to be 94.2% using the β-carotene bleaching method. Five phenolic compounds including caffeic acid, syringic acid, vanillin, ellagic acid, and cinnamic acid were quantified by high performance liquid chromatography (HPLC). It is suggested that the roots of the hybrid Phalaenopsis Sogo Yukidian “V3” cultivar may be exploited as an effective source of antioxidants.

Identification and control of pathogenic fungi in neotropical valued orchids (Laelia spp.)

Laelia species are valued orchids for ornamental and ritual uses. Since their natural populations are at risk, a suitable alternative is cultivation. However, the fungi affecting orchid cultivars are largely unknown. In this study, pathogenic fungi of Laelia autumnalis, L. rubescens, and L. speciosa in cultures of Morelia city orchid collections were identified using molecular and morphological methods. Pathogenicity tests were conducted using in vitro L. speciosa seedlings and a bioassay with three fungicides. Thirty-nine strains belonging to 10 taxa were isolated: Aspergillus fumigatus, Colletotrichum boninense, C. karstii, Fusarium bactridioides, F. oxysporum, F. proliferatum, F. solani, Fusarium sp., Xylaria feejeensis, and an Ascomycete strain. The most common pathogens in adult plants were F. proliferatum and A. fumigatus. The most aggressive fungus was F. solani. The Ascomycete, A. fumigatus and X. feejeensis, are reported herein as opportunistic orchid pathogens for the first time under in vitro conditions. The fungicide thiabendazole significantly inhibited the growth of F. proliferatum and F. solani, while benomyl inhibited the growth of A. fumigatus and F. bactridioides after five days. All tested fungicides did not inhibit the growth of C. boninense, F. oxysporum, Fusarium sp., and the Ascomycete strain. Our results will be useful to improve management recommendations for these endangered orchid species.

Orchid weevils (Coleoptera: Curculionidae) in Canada

AbstractThe study presents information about the taxonomy, natural history, and distribution of orchid weevils (Coleoptera: Curculionidae) in Canada. Native areStethobaris ovata(LeConte, 1869) (=S. congermanaCasey, 1892restored synonymy;=S. convergensCasey, 1920new synonymy),S. incomptaCasey, 1892 (=S. commixtaBlatchley, 1916new synonymy), andS. sacajaweaePrena,new species, with all of them also being present in the adjacent temperate zone of the United States of America.Orchidophilus aterrimus(Waterhouse, 1874) andS. laevimargo(Champion, 1916) have been found on imported orchid cultivars but did not become established in natural habitats.

Genetic diversity of 129 spring orchid (Cymbidium goeringii) cultivars and its relationship to horticultural types as assessed by EST-SSR markers

Spring orchid (Cymbidium goeringii), a valuable and endangered species in China, plays an important role as a potted flower. The genetic diversity of 129 spring orchid cultivars was evaluated with 13 selected EST-SSR markers and 120 alleles were identified, of which 111 alleles were polymorphic. The plum petal type, with 43 cultivars, contributed 102 polymorphic alleles out of the 111, while the colored flower type, with 3 cultivars, had 38 polymorphic alleles. Cluster analysis showed that these 129 spring orchid cultivars could be sorted into two groups, or three subgroups (A1, A2, B), based on the allelic data, and with all cultivars from three currently recognized variants intermingled with some cultivars from C. goeringii in the same subgroup, indicating that they should not be regarded as variants. Through principal coordinate analysis, only a weak correlation between DNA fingerprints and the horticultural types of the spring orchid was observed. However, common alleles existed in cultivars from the same horticultural type, for example, 15 common alleles were found in the 3 cultivars of the colored flower type, and the CY2-J allele existed in the 43 cultivars of the plum petal type. All these cultivars, except for Longzi and Lao Longzi, could be distinguished from each other using these EST-SSR markers. Moreover, a set of 102 out of the 129 cultivars had their own specific alleles, and therefore, with a single EST-SSR marker, each of these cultivars can be distinguished from all other cultivars. These findings can be valuable for taxonomy improvement as well as resource conservation and utilization, and the EST-SSR markers developed can also be a useful tool for cultivar identification which is frequently required commercially.