Lilium Oriental Research Articles

Transcriptome-Wide Identification of miRNAs and Their Targets During Riboflavin-Promoted Dormancy Release in Lilium ‘Siberia’

Dormancy release is an important process for improving the quality of cut-flower lily production and promoting the factory production of lily bulbs. However, the regulatory mechanisms of microRNAs (miRNAs) and their target genes during the dormancy release of lily remain elusive. Anatomy, transcriptomic, molecular biology, and transient transformation techniques involving subcellular localization were applied in our study. There were significant results showing that 0.1 mM riboflavin promoted dormancy release and floral bud differentiation and influenced the flowering time of the Lilium ‘Siberia’. Moreover, some differentially expressed miRNAs and their targets (miR395-y: LoAPS1, miR529-z: LoSPL14, miR396-y: LoCFDP1, miR1863-z: LoFBA3, miR399-y: LoDIT1, and miR11525-z: Lopgm) were identified and predicted. Exogenous riboflavin may activate primary metabolic processes and promote dormancy release in Lilium ‘Siberia’ bulbs. Furthermore, riboflavin upregulated genes related to the riboflavin pathway, H3K4me3 methylation, dormancy control, and the flowering pathway and downregulated dormancy maintenance genes. Moreover, riboflavin promoted endogenous riboflavin and acetyl-CoA accumulation. LoPurple acid phosphatase17 (LoPAP17), a pivotal gene of the riboflavin metabolism pathway, was subsequently cloned. LoPAP17 was most closely related to the orthologous genes of Acorus calamus, Asparagus officinalis, and Musa acuminata. The LoPAP17 protein was subcellularly located in the nucleus. Our study revealed that miRNAs and their target genes might regulate the primary metabolic pathway, promote the accumulation of endogenous riboflavin and acetyl-CoA, and affect protein acetylation during the riboflavin-promoted release of dormancy and flower bud differentiation in the Lilium Oriental hybrid ‘Siberia’.

LoBLH6 interacts with LoMYB65 to regulate anther development through feedback regulation of gibberellin synthesis in lily

Abstract The homeostasis of gibberellin (GA) is crucial for the normal development of anthers, but its underlying regulatory mechanisms are not clear. The GA induced v-Myb myeloblastosis viral oncogene homolog (MYB) transcription factor LoMYB65 is involved in anther development. In this study, we screened and identified an interacting protein of LoMYB65, Lilium Oriental Hybrids BEL1-Like Homeodomain6 (LoBLH6). LoBLH6 was localized in both the nucleus and cytoplasm, and it interacted with LoMYB65 through its BELL domain, exhibiting transcriptional repression activity. LoBLH6 was continuously expressed during anther development, with particularly high expression in the mid and late stages. In situ hybridization revealed high expression of LoBLH6 in the tapetum and microspores, with the same tissue specificity as LoMYB65. Silencing of LoBLH6 in lilies resulted in abnormal anther development, reduced pollen, and increased GA content. The application of GA induced phenotypes in the anthers and pollen of lily that were similar to the silencing of LoBLH6. Further research showed that LoBLH6 directly binds to the promoter of Lilium Oriental Hybrids GA 20-oxidase1 (LoGA20ox1) to suppress its expression, and co-expression with LoMYB65 enhances this repression. Additionally, GA treatment enhanced the interaction between LoBLH6 and LoMYB65 and their complex's inhibitory effect on downstream target genes. During the transition from microspores to mature pollen grains in lily anthers, GA levels maintain a steady state, which is disrupted by silencing LoBLH6, leading to abnormal pollen development. Overall, our results reveal that the interaction between LoBLH6 and LoMYB65 regulates anther development through feedback regulation of GA synthesis.

Identification and Expression Analysis of Putative Sugar Transporter Gene Family during Bulb Formation in Lilies.

Sugar transporters play important roles in plant growth and development, flowering and fruiting, as well as responses to adverse abiotic and biotic environmental conditions. Lilies (Lilium spp.) are some of the most representative ornamental bulbous flowers. Sugar metabolism is critical for bulb formation in lilies; therefore, clarifying the amount and expression pattern of sugar transporters is essential for further analyzing their roles in bulb formation. In this study, based on the transcriptome data of the Lilium Oriental hybrid 'Sorbonne' and Lilium × formolongi, a total of 69 and 41 sugar transporters were identified in 'Sorbonne' and Lilium × formolongi, respectively, by performing bioinformatics analysis. Through phylogenetic analysis, monosaccharide transporters (MSTs) can be divided into seven subfamilies, sucrose transporters (SUTs) can be divided into three subgroups, and sugars will eventually be exported transporters (SWEETs) can be divided into four clades. According to an analysis of conserved motifs, 20, 14, and 12 conserved motifs were predicted in MSTs, SUTs, and SWEETs, respectively. A conserved domain analysis showed that MSTs and SUTs contained a single domain, whereas most of the SWEETs harbored two MtN3/saliva domains, also known as a PQ-loop repeat. The LohINT1, which was predicted to have a smaller number of transmembrane structural domains, was cloned and analyzed for subcellular localization. It was found that the LohINT1 protein is mainly localized in the cell membrane. In addition, the expression analysis indicated that 22 LohMSTs, 1 LohSUTs, and 5 LohSWEETs were upregulated in 'Sorbonne' 1 day after scale detachment treatment, suggesting that they may regulate the initiation of the bulblet. A total of 10 LflMSTs, 1 LflSUTs, and 6 LflSWEETs were upregulated 4~6 months after sowing, which corresponds to the juvenile-to-adult transition phase of Lilium × formolongi, suggesting that they may also play a role in the accompanying bulb swelling process. Combined with quantitative real-time PCR (qRT-PCR) analysis, LohSTP8 and LohSTP12 were significantly overexpressed during the extremely early stage of bulblet initiation, and LflERD6.3 was significantly overexpressed during the growth of the underground bulblet, suggesting that they may be key sugar transporters in the formation of lily bulbs, which needs further functional verification.

Acoustic levitation of pollen and visualisation of hygroscopic behaviour

Abstract. Pollen are hygroscopic; therefore, they have the potential to act as cloud condensation nuclei (CCN) in the atmosphere. This could have uncertain implications for cloud processes and climate as well as plant biodiversity and human health. Previous studies have investigated the hygroscopic swelling of pollen, linked to CCN activity by the κ-Köhler theory, using methods that follow observed mass increase by electrodynamic balance (EDB) or vapour sorption analyser. This study uses an acoustic levitator to levitate pollen grains in the true aerosol phase and uses a macroscope to image the pollen to investigate hygroscopic behaviour when relative humidity (RH) is changed. Two pollen species were studied in this work: Lilium orientalis (oriental lily) and Populus deltoides (eastern cottonwood). Both species were successfully levitated; however, the smaller Populus deltoides showed greater instability throughout experiments. The quality of images taken by the macroscope, and thus calculations of pollen area and aspect ratio, varied significantly and were sensitive to lighting conditions as well as to levitated pollen grain movement and orientation. Experiments with surface-fixed pollen grains were also conducted. They showed evidence that pollen hygroscopic swelling could be observed by the macroscope. The produced results were comparable with previously reported mass increase values. Although less accurate than methods that measure mass changes, the acoustic levitator and macroscope set-up offer an attractive alternative by virtue of being commercial, off-the-shelf, low-cost, and versatile techniques. A key advantage of this method is that it is possible to visually observe particle shape dynamics under varying environmental conditions.

Effect of Different Growing Media on Growth and Flower Production of Oriental Lily (Lilium orientalis)

Oriental lily (Lilium orientalis L.) is a popular and beautiful flowering plant known for its large, colorful, and fragrant blooms. Oriental lilies are perennial plants that grow from bulbs and can reach impressive heights, producing tall and sturdy stems. Their flowers come in various striking colors, including shades of pink, white, red, and bi-color combinations. Growing media, also known as potting mix or substrate, refers to the material used to grow plants in containers, pots, or raised beds. It is a crucial component in container gardening and hydroponics, as it provides physical support, nutrients, and aeration for plant roots to grow and thrive. Therefore, present investigation was carried out at the Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture Technology and Sciences, Prayagraj, Uttar Pradesh during Winter-2022-23 with a view to determine the effect of different growing media and different varieties of oriental lily for its growth, flowering, yield and to work out the economics of various treatments. Under this experiment, two factors viz., 3 different varieties (factor A) and 6 treatments comprising of different growing media (factor B) were used. The study was examined using factorial randomized block design. From the present investigation it is concluded that the media V2M3 (Trocadero variety was grown in Soil + Sand + Vermicompost + Vermiculite (1:1:1:1) was found to be the best in terms of vegetative growth, flowering, and bulb production. In case of bulblets of lilium, was to all best with media V3M3 (Robina variety was grown in Soil + Sand + Vermicompost + Vermiculite (1:1:1:1) was found best. The highest benefit cost ratio was recorded 2.57 with a M3 (Soil + Sand + Vermicompost + Vermiculite (1:1:1:1).

Transcriptomic analysis reveals candidate genes associated with anther development in Lilium Oriental Hybrid 'Siberia'.

Lily (Lilium spp. and hybrids) is an important cut flower crop worldwide. Lily flowers have large anthers, which release a large amount of pollen that stains the tepals or clothing and thus can affect the commercial value of cut flowers. In this study, lily Oriental 'Siberia' was used to investigate the regulatory mechanism of lily anther development, which may provide information to prevent pollen pollution in the future. Based on the flower bud length, anther length and color, and anatomical observations, lily anther development was categorized into five stages: green (G), green-to-yellow 1 (GY1), green-to-yellow 2 (GY2), yellow (Y), and purple (P). Total RNA was extracted from the anthers at each stage for transcriptomic analysis. A total of 268.92-Gb clean reads were generated, and 81,287 unigenes were assembled and annotated. The number of differentially expressed genes (DEGs) and unique genes were largest for the pairwise comparison between the G and GY1 stages. The G and P samples were clustered separately, whereas the GY1, GY2, and Y samples were clustered together in scatter plots from a principal component analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of DEGs detected in the GY1, GY2, and Y stages revealed that the pectin catabolic process, hormone levels, and phenylpropanoid biosynthesis were enriched. The DEGs associated with jasmonic acid biosynthesis and signaling were highly expressed at the early stages (G and GY1), whereas the DEGs associated with phenylpropanoid biosynthesis were mainly expressed in the intermediate stages (GY1, GY2, and Y). The DEGs involved in the pectin catabolic process were expressed at advanced stages (Y and P). Cucumber mosaic virus-induced gene silencing of LoMYB21 and LoAMS caused a strongly inhibited anther dehiscence phenotype, but without affecting the development of other floral organs. These results provide novel insights for understanding the regulatory mechanism of anther development in lily and other plants.

Full-Length Transcriptome Characterization and Functional Analysis of Pathogenesis-Related Proteins in Lilium Oriental Hybrid 'Sorbonne' Infected with Botrytis elliptica.

Gray mold (Botrytis elliptica) causes a deleterious fungal disease that decreases the ornamental value and yield of lilies. Lilium oriental hybrid 'Sorbonne' is a variety that is resistant to gray mold. Understanding the mechanism of resistance against B. elliptica infection in 'Sorbonne' can provide a basis for the genetic improvement in lily plants. In this study, a PacBio Sequel II system was used to sequence the full-length transcriptome of Lilium 'Sorbonne' after inoculation with B. elliptica. A total of 46.64 Gb subreads and 19,102 isoforms with an average length of 1598 bp were obtained. A prediction analysis revealed 263 lncRNAs, and 805 transcription factors, 4478 simple sequence repeats, and 17,752 coding sequences were identified. Pathogenesis-related proteins (PR), which may play important roles in resistance against B. elliptica infection, were identified based on the full-length transcriptome data and previously obtained second-generation transcriptome data. Nine non-redundant potential LhSorPR proteins were identified and assigned to two groups that were composed of two LhSorPR4 and seven LhSorPR10 proteins based on their genetic relatedness. The real-time quantitative reverse transcription PCR (qRT-PCR) results showed that the patterns of expression of nine differentially expressed PR genes under B. elliptica stress were basically consistent with the results of transcriptome sequencing. The pattern of expression of LhSorPR4s and LhSorPR10s genes in different tissues was analyzed, and the expression of each gene varied. Furthermore, we verified the function of LhSorPR4-2 gene in Lilium. The expression of LhSorPR4-2 was induced by phytohormones such as methyl jasmonate, salicylic acid, and ethephon. Moreover, the promoter region of LhSorPR4-2 was characterized by several functional domains associated with phytohormones and stress response. The overexpression of LhSorPR4-2 gene in 'Sorbonne' increased the resistance of the lily plant to B. elliptica and correlated with high chitinase activity. This study provides a full-length transcript database and functionally analyzed the resistance of PR gene to B. elliptica in Lilium, thereby introducing the candidate gene LhSorPR4-2 to breed resistance in Lilium.

Heterologous Expression of LiSEP3 from Oriental Lilium Hybrid 'Sorbonne' Promotes the Flowering of Arabidopsis thaliana L.

The MADS-box gene family has multiple molecular and biological functions in plants. Here, the LiSEP3 gene of the MADS-box gene family of' 'Sorbonne' was obtained by homologous cloning using the petals of the flowering stage of Lilium Oriental Hybrid 'Sorbonne.' The ORF full-length sequence is 729bp, encoding 242 amino acids. Bioinformatics analysis showed that the relative molecular weight of the LiSEP3 protein is 27.67 kD and the isoelectric point (pI) is 9.16. The prediction result of the gene positioning is transcription in its nucleus. Homologous alignment of amino acid sequences showed that the protein not only had typical MADS-box and K-box domains, but also contained two short and relatively conservative SEP motifs. The phylogenetic tree showed that the amino acid sequence encoded by the LiSEP3 gene had the closest relationship with SEP3 in monocotyledon plants such as Apostasia odorata. The results of real-time PCR showed that LiSEP3 gene was mainly expressed in petal. During flower development, the expression level of the LiSEP3 gene showed an overall trend of initially increasing and then decreasing. The flowering time of LiSEP3 transgenic Arabidopsis thaliana L. plants was earlier than that of wild-type Arabidopsis thaliana L. plants, compared with wild type, the number of rosette leaves is less. In the transgenic plants, the expression of flowering-associated AtSPL5 and AtGI genes was up-regulated, while the expression of AtSVP and AtFRI genes that inhibit flowering was down-regulated, which was consistent with the statistical results of the flowering time of LiSEP3 transgenic plants. Our results illustrate that the heterologous expression of SEP3 functional genes in the MADS-box family promoted the flowering period of transgenic plants of this hybrid. This research provides a theoretical basis for improving the flowering period of ornamental plants through plant genetic engineering technology and enhancing their economic and social values.

Cold Storage Period of Bulbs Influences Their Sugar Contents and Post-Storage Growth and Flowering in Lilium Oriental Hybrids

This study was carried out to investigate the changes in internal shoot growth, total and reducing sugar content, plant growth, and flowering characteristics after cold-stored bulbs of Lilium Oriental Hybrids are planted. Bulbs of Lilium Oriental Hybrids ‘Le Reve’, ‘Sorbonne’, and ‘Siberia’ were harvested at the end of November, cleaned, treated with fungicides, conditioned for 30 days at 4 °C, and cold-stored for 30 to 120 days at 0 °C. Plant height, fresh and dry weights, leaf numbers and area, chlorophyll content (SPAD index), days to flowering, number of flower buds, and flower diameter were measured when the cut flowers were harvested. In all cultivars, the shoot lengths in the bulbs increased as the storage period increased. As the storage period was extended, the fructose and glucose contents increased, whereas sucrose content decreased. The total sugar content increased during the early storage period and decreased subsequently. Plant height, fresh and dry weights of cut flowers showed a decreasing trend as the storage period increased. Flower diameter generally decreased with increasing storage period but varied among cultivars. These results indicated that more storage carbohydrates in bulbs were consumed as the storage period increased, and thus, the subsequent plant growth and flowering were negatively affected.

Isolation and characterization of LoAMS gene in anther development of lily (Lilium oriental hybrids)

ABSTRACT Lily is one of the most valuable fresh cut flowers in the world. However, pollen pollution brings inconvenience to retailers and consumers. Anther development is a complicated and precise process but much is unknown. In this study, the anther development key gene LoAMS was isolated from Lilium Oriental Hybrids cultivar ‘Siberia’. Phylogenetic tree analysis and multiple sequence alignment showed that LoAMS protein had a typical basic helix–loop–helix domain (bHLH), belonging to the MYC transcription factor family. Furthermore, the subcellular localization experiment revealed that LoAMS was a nucleus protein. Transcriptional activation assays showed LoAMS was a transcriptional activator with the transcriptional activation domain in the last 204 amino acids (338-541aa) of the C-terminal region. The real-time quantitative PCR showed that LoAMS was abundant in lily anthers. Two peak expressions of LoAMS appeared in the anthers of 3-cm and 10-cm flower buds, especially in the microspores of 10-cm flower buds. These data indicate LoAMS is an anther specific transcriptional activator that may contribute to lily molecular breeding in the near future.

High-efficiency somatic embryogenesis techniques for different hybrids of cut lilies

Somatic embryogenesis (SE) is a unique method of in vitro regeneration for plant reproduction, germplasm resource preservation, and molecular-assisted breeding. Although lily is an internationally valued ornamental plant, its SE technology is still incomplete. Here, the effects of different explants, picloram (PIC) concentrations, and light conditions on somatic embryo induction, development, germination and seedling formation were studied in five Lilium varieties belonging to different hybrids. The embryo histomorphology, development and origins were observed, and a broadly efficient embryogenesis system was firstly established in Lilium. With leaf explants, all varieties tested underwent indirect somatic embryogenesis (SE). With scale explants, the Lilium Asiatic ‘Strawberry and Cream’, Lilium Oriental ‘Double Surprise’, and Lilium longiflorum Thunb. ‘White Heaven’ underwent indirect SE and the Lilium longiflorum × Asiatic hybrid ‘Eyeliner’ and Lilium longiflorum × Oriental ‘Triumphator’ underwent direct SE. Somatic embryogenesis in the above varieties involved four stages: globular, heart-shaped, torpedo-shaped, and cotyledon embryos. Two original SE pathways (endogenous and exogenous) were observed, and their appearance times differed. In indirect SE, exogenous embryos appeared first, followed by endogenous embryos; whereas in direct SE, the order was reversed. The different somatic embryo origins and the proportion of internal and external origins were closely related to the occurrence of somatic embryos by direct or indirect pathways and significantly affected the induction cycle of somatic embryos. Dark culture promoted lily somatic embryo induction, while 16 h/day light culture promoted germination, and the germination rates of all five lily varieties exceeded 90%. Murashige Skoog (MS) medium + (1.5–2.5 mg L−1) PIC + 0.2 mg L−1 1-Naphthaleneacetic acid (NAA) was suitable for SE from lily leaves and scales with an induction efficiency of 88–96%. Our research developed a widely applicable regeneration procedure for different hybrids of lily via somatic embryogenesis. Morphohistological analysis confirmed the origins, developmental stages and dynamic changes of cells during in vitro morphogenesis. This study will provide a valuable reference for the propagation of Lilium.

English

Ultra-morphology and pollen viability assessment are essential to understand evolutionary ecology and sterility problem, and to design hybridization program in cross-breeding. The pollen ultra-morphology of two Lilium Oriental hybrid cultivars, „Sorbonne‟ and „Siberia‟ were observed using scanning electron microscope. And the pollen germination condition in vitro and four dye tests methods for pollen viability were determined. The results showed that pollens of two Lilium Oriental hybrid cultivars were much alike in ultra-morphology with ellipsoidal shape, reticulate surface decoration and single germination ditch, indicating a close genetic relationship between two cultivars. The suitable medium for pollen germination of two cultivars composed of 10% sucrose, 0.1% boric acid and 0.5% agar. The pollen germination percent reached the highest at 25oC. Although I2-KI stain, TTC stain and peroxidase precipitation methods were not suitable for lily pollen viability test, the pollen viability tested by acetocarmine method were close to that by in vitro pollen germination at suitable condition, which suggested acetocarmine stain can be as a quick test method for pollen viability of Lilium Oriental hybrids. © 2018 Friends Science Publishers

Aphelenchoides smolae n. sp. (Tylenchina: Aphelenchoididae) found in Lilium orientalis imported into China from The Netherlands

Summary Aphelenchoides smolae n. sp. isolated in Ningbo Port, China, from medium soil and tissues of Lilium orientalis bulbs imported from The Netherlands, is described. It is characterised by the female body length of 826 (672-1002) μm and male body length of 785 (683-844) μm, lateral field with four lines (three bands), stylet 13.0-14.9 μm long with small basal swellings, excretory pore situated slightly posterior to nerve ring, vulval flap absent, post-vulval uterine sac well developed and extending for ca 35.7-62.4% of vulva to anus distance, conical tail with terminus bearing a single mucron with many tiny nodular protuberances under SEM, males common, with spicules 25.7-29.8 μm long (median curved line), the condylus and rostrum rounded, well developed, the dorsal limb with a hook-like tip, and tail bearing three pairs (2 + 2 + 2) of caudal papillae and a sharply pointed mucron. The new species belongs to the Group 2 category of Aphelenchoides species sensu Shahina. Phylogenetic analysis based on 18S, 28S D2-D3 of rDNA and COI mtDNA further characterised the new species.

Factors affecting in vitro bulblet growth of Lilium orientalis ‘Stargazer’ and ‘Casablanca’

ISHS XXX International Horticultural Congress IHC2018: II International Symposium on Micropropagation and In Vitro Techniques Factors affecting in vitro bulblet growth of Lilium orientalis 'Stargazer' and 'Casablanca'

In vitro bulb formation of direct and indirect regeneration of Lilium orientalis cv. \u201cStarfighter\u201d plants

BackgroundLily is one of the most important commercial cut flower species and one of the three major bulb crops in the commercial market. The aim was to assess and establish a suitable protocol for increasing the number of Lilium bulblets and enlarge their size.MethodologyDifferent plant growth regulators (TDZ, 2,4-D, 2ip, and picloram) at different concentrations for direct and indirect micropropagation were used. Also, the effect of various concentrations of sucrose alone or with growth inhibitor on bulblet formation during three repeated subcultures was examined with anatomical study.ResultsFor direct shoot organogenesis, culturing leaf explant on MS culture medium containing TDZ (0.5 mg/l) + 2,4-D (10 mg/l) led to the highest number of shootlets after 1 month. For indirect micropropagation, MS was supplemented with 2ip (0.5 mg/l) + picloram (5 mg/l)-induced callus tissues which were differentiated to embryos then weak shoots after 3 months. For more proliferation, the highest numbers of shootlets, leaves, and bulb scales were observed on MS culture medium supplemented with 1.0 mg/l of BA plus 0.2 mg/l NAA. Using 60 g/l of sucrose plus 3 or 6 mg/l of paclobutrazol led to the highest number of bulblets/explant for the third subculture. The highest bulblet diameters were recorded with 120 g/l sucrose plus 6 or 3 mg/l paclobutrazol.ConclusionThis study had reached to optimize a suitable protocol for direct and indirect micropropagation of Lilium orientalis cv. “Starfighter” bulbs and increase the number and size of bulbs that can be beneficial for increasing the production and reduce their price. This study will help the producers for commercial purposes.

Transcriptome analysis of Lilium Oriental × Trumpet hybrid roots reveals auxin-related genes and stress-related genes involved in picloram-induced somatic embryogenesis induction

ABSTRACTHighly efficient somatic embryogenesis (SE) initiation systems are crucial for the clonal propagation and genetic transformation of Lilium Oriental × Trumpet hybrid. To elucidate the underlying mechanism of SE induction, we conducted de novo transcriptome sequencing of the roots at four different times in relation to SE initiation (0 days, control; 20 days, embryogenic callus induction (ECI) 1; 40 days, ECI2; 55 days, ECI3). A total of 4621, 7582, and 7427 differentially expressed genes (DEGs) were identified from the ECI1 vs. control, ECI2 vs. control, and ECI3 vs. control comparisons, respectively. The gene-enrichment analysis revealed 54 significant DEGs. Further analysis showed that the transcript levels of the auxin-related genes ARF9/15/16, the abscisic acid-related (ABA-related) genes PYL4/9, and stress-related transcription factors, including WRKY26, MYB36, NAC100, bHLH2/5/18/112, and HSP90, were increased at the ECI1 stage. ABI5 can influence the expression of stress-responsive genes as an ABA signalling regulator. The upregulated ABI5 could be caused by the increased ARF9/15/16, PYL4/9, WRKY26, MYB36, NAC100, bHLH2/5/18/112, and HSP90 at the ECI2 and ECI3 stages to regulate the ECI. These genes had the most abundant transcripts among the DEGs, indicating that auxin and stress-related signalling pathways are involved in SE initiation of Lilium spp.

Cryopreservation of small leaf squares-bearing adventitious buds of Lilium Oriental hybrid ‘Siberia’ by vitrification

We report a new cryopreservation method for Lilium Oriental hybrid ‘Siberia’. Adventitious buds were induced from leaf segments cultured for 12 days on adventitious bud induction medium composed of half-strength Murashige and Skoog medium (MS) supplemented with 1 mg L−1 α-naphthalene acetic acid and 0.5 mg L−1 thidiazuron. Small leaf squares (SLSs, 3 × 4 mm), each bearing at least one adventitious bud, were cut from leaf segments, precultured on medium with 0.5 M sucrose for 1 day, and then treated for 20 min with a loading solution containing 0.4 M sucrose and 2 M glycerol, followed by exposure to plant vitrification solution 2 for 7 h at 0 °C. Dehydrated SLSs were directly immersed in liquid nitrogen for 1 h. Cryopreserved SLSs were re-warmed in MS medium containing 1.2 M sucrose for 20 min at room temperature, followed by post-thaw culture for recovery. With this procedure, 85% survival and 72% shoot regrowth were achieved following cryopreservation. The use of SLSs bearing adventitious buds for cryopreservation reported in the present study eliminates the time-consuming and labour-intensive step of shoot tip excision, and has great potential to facilitate cryopreservation in other plant species.

The characterization of anther-specific promoter encoding chalcone synthase isolated from Lilium Oriental hybrid cv. Acapulco

The characterization of anther-specific promoter encoding chalcone synthase isolated from Lilium Oriental hybrid cv. Acapulco

Cross-compatibility of different lily hybrid cultivars

Conventional cross-breeding is still the main method to obtain new cultivars around the world. Here, crossing was made by a normal pollination technique to study the intra- and interspecific cross-compatibility of 46 lily cultivars. One hundred and twenty-nine crosses were designed among 46 cultivars (including Lilium Asiatic hybrids (A), Lilium Oriental hybrids (O), Lilium Longiflorum hybrids (L), hybrids of Longiflorum × Asiatic (LA) and hybrids of Oriental × Trumpet (OT)), which differ in flower color, flower spots, flower type, fragrance and plant height. A total of 1699 flowers were pollinated. Thirty-one crosses obtained tissue culture progeny that could be used as good breeding material. Results demonstrated that most of the crosses in the same hybrid group were compatible. Fruits and embryos were obtained easily in intraspecific crosses of Asiatic hybrids (fruits were obtained in 32 out of 38 crossing types, and embryos were obtained in 24 crossing types) Six of 11 A × LA, 17 of 21 LA × A and eight OT × O combinations had fruits and even embryos for the bridging function of Asiatic and Oriental hybrids. However, interspecific pollinations of A × L, A × O and O × A were less compatible, resulting in low percentage of setting seeds. We obtained five segregating populations with different color and spot traits, and three segregating populations with different plant heights from crosses of high seed setting rate and embryo numbers. Based on these results, we provide a new reference for lily crosses selection.

Efficient Agrobacterium-mediated transformation of Lilium Oriental ‘Sorbonne’ with genes encoding anthocyanin regulators

Plant anthocyanin biosynthesis is regulated by a combination of transcription factors. Here, exogenous anthocyanin regulator genes Delila/Rosea1 (Del/Ros1) or Bperu/Colored aleurone1 (B1/C1) were i...