Floricultural Plants Research Articles

Isolation and characterization of the C-class MADS-box gene involved in the formation of double flowers in Japanese gentian.

BackgroundGenerally, double-flowered varieties are more attractive than single-flowered varieties in ornamental plants. Japanese gentian is one of the most popular floricultural plants in Japan, and it is desirable to breed elite double-flowered cultivars. In this study, we attempted to characterize a doubled-flower mutant of Japanese gentian. To identify the gene that causes the double-flowered phenotype in Japanese gentian, we isolated and characterized MADS-box genes.ResultsFourteen MADS-box genes were isolated, and two of them were C-class MADS-box genes (GsAG1 and GsAG2). Both GsAG1 and GsAG2 were categorized into the PLE/SHP subgroup, rather than the AG/FAR subgroup. In expression analyses, GsAG1 transcripts were detected in the second to fourth floral whorls, while GsAG2 transcripts were detected in only the inner two whorls. Transgenic Arabidopsis expressing GsAG1 lacked petals and formed carpeloid organs instead of sepals. Compared with a single-flowered gentian cultivar, a double-flowered gentian mutant showed decreased expression of GsAG1 but unchanged expression of GsAG2. An analysis of the genomic structure of GsAG1 revealed that the gene had nine exons and eight introns, and that a 5,150-bp additional sequence was inserted into the sixth intron of GsAG1 in the double-flowered mutant. This insert had typical features of a Ty3/gypsy-type LTR-retrotransposon, and was designated as Tgs1. Virus-induced gene silencing of GsAG1 by the Apple latent spherical virus vector resulted in the conversion of the stamen to petaloid organs in early flowering transgenic gentian plants expressing an Arabidopsis FT gene.ConclusionsThese results revealed that GsAG1 plays a key role as a C-functional gene in stamen organ identity. The identification of the gene responsible for the double-flowered phenotype will be useful in further research on the floral morphogenesis of Japanese gentian.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0569-3) contains supplementary material, which is available to authorized users.

Transforming the Snapdragon Aurone Biosynthetic Genes into Petunia Alters Coloration Patterns in Transgenic Flowers

Aurones belong to a small class of flavonoids that provide yellow color in some floricultural plants including snapdragon. To explore novel flower coloration, two full-length cDNAs encoding chalcone 4'-O-glucosyltransferase (designated as SRY4'CGT) and aureusidin synthase (designated as SRYAS1) in the aurone biosynthetic pathway were cloned from yellow flowers of snapdragon (Antirrhinum majus cv. Ribbon Yellow). Binary vectors were constructed and transformed separately into Petunia hybrida harboring blue flowers. Only a few flowers in 4 out of 9 transgenic SRY4'CGT plants showed variegated blue-white sectors; as time passed, amounts of variegated flowers and proportion of white sectors in the background blue color of the new-born flowers gradually increased, until finally, the petal color was completely white in all late-born flowers. In contrast, a few flowers in 3 out of 13 transgenic SRYAS1 plants showed variegated blue-white sectors; but, the amounts of variegated flowers did not increase over the whole flowering stage, and no complete white flowers were observed. RNA samples isolated from blue and white sectors of T1 transgenic SRY4'CGT plants were analyzed by reverse transcription-PCR, transgenic SRY4'CGT transcripts were detected in both sectors; however, transcripts of an upstream gene, chalcone synthase (CHS), were abundantly detected in the blue sectors but largely reduced in the white sectors, suggesting that the expression of CHS gene was suppressed in white sectors of transgenic plants. Furthermore, HPLC coupled with mass spectrometry demonstrated cyandin, malvidin and their derivatives were absent in white sectors, causing the white phenotype. Our findings may be attractive to molecular breeders.

Amblyseius swirskii in greenhouse production systems: a floricultural perspective

The predatory mite Amblyseius swirskii Athias-Henriot is a biological control agent that has the potential to play an important role in pest management in many greenhouse crops. Most research on this predatory mite has focused on its use and efficacy in greenhouse vegetables. However, an increasing number of growers of greenhouse ornamental crops also want to adopt biological control as their primary pest management strategy and find that biological control programs developed for vegetables are not optimized for use on floricultural plants. This paper reviews the use of A. swirskii in greenhouse crops, where possible highlighting the specific challenges and characteristics of ornamentals. The effects of different factors within the production system are described from the insect/mite and plant level up to the production level, including growing practices and environmental conditions. Finally, the use of A. swirskii within an integrated pest management system is discussed.

Conjoint Analysis of the Korean Floriculture Market for the Main Cut Flowers to Predict the Demand for Floriculture Plants

본 연구에서는 소비자들의 주요 절화류에 대한 구매행동과 인식을 파악하여 시장을 예측하고, 소비 활성화 방안을 제시하고자 하였다. 설문조사를 전문 리서치 기관에 대행하여 실시하였고, 주요 절화류를 대상을 조사를 하여 컨조인트 및 군집분석을 하였다. 설문조사결과, 장미의 경우는 선택 속성별 중요도는 가격과 절화수명이 비슷하게 높았으며, 그 다음으로 화색, 화형의 순으로 분석되었다. 각 속성별 부분가치를 보면, 가격은 1000원, 꽃의 형태는 군집1의 남성의 경우만 빼고 여성 군집 2,3,4,5,6,7의 경우 모두 스프레이 형태의 장미를 선호하였다. 꽃의 절화수명에 대한 중요도는 높은 수준을 보여 모든 군집에서 7-8일로 나타났고 화색은 빨강색을 가장 선호하였다. 국화의 경우 선택속성별 중요도는 화색이 가장 높고, 그 다음으로 절화수명, 화형, 가격 순으로 분석되었다. 부분가치를 보면 가격은 1000원, 화형은 스탠다드, 절화수명은 16-20일, 화색은 노란색이 가장 높았다. 백합의 경우 선택속성별 중요도는 화형이 가장 높았고, 그 다음으로 절화수명, 가격, 화색 등의 순으로 분석되었다. 부분가치를 보면, 가격은 2000원, 화형은 대형을, 절화수명은 4-7일, 화색은 노란색이 가장 높았다. 주요 절화(장미, 국화, 백합)을 대상으로 컨조인트 분석 결과, 장미의 경우 가격과 절화수명이 가장 높게 나타났으며, 국화는 절화수명과 화색, 백합은 화형과 절화수명으로 나타났다. 주요 절화 모두 공통적으로 절화수명의 중요도가 높은 것으로 나타났다. 본 연구에서는 소비자 조사를 통해 주요 절화류에 대한 소비자의 선호 패턴을 분석하고 이를 근거로 소비자의 기호에 맞는 상품을 기획 생산하여 화훼류 소비 활성화 방안을 위한 기초조사 자료를 제시하고자 하였다. This study was conducted to improve the consumption of floriculture plants by researching preferences of consumers for the main types of cut flowers. We analyzed the results of surveys, carried out by a company, that were largely about roses, chrysanthemums, and lilies. After departmentalizing consumers into groups and analyzing the results through conjoint and cluster analysis, we found that consumers showed a higher rate of use based on price and vase life than on flower color and flower shape in roses. The groups of rose consumers preferred a price of 1000 won, spray type flower shape, vase life of 7-8 days, and red flower color. In chrysanthemums, consumers showed higher rate of use for flower color than for vase life, flower shape, and price. The groups of chrysanthemum consumers preferred a price of 1000 won, standard flower shape, 16-20 days vase life, and yellow flower color. In lilies, consumers showed higher use rate for flower shape than vase life, price, and flower color. Lily consumers preferred a price of 2000 won, large flower shape, 4-7 days vase life, and yellow flower color. Thus, the major cut flowers (rose, chrysanthemum, and lily) all showed highest use rates in for vase life. These results highlight the importance of understanding the characteristics of consumer interests. They also emphasize that we should plan and create market-oriented and consumer-oriented products to improve the consumption of floriculture plants.

A Research Strategy to Understand the Mechanisms that Govern Flower Color Pattern Formation

The coloration pattern of flower tissue affects the commercial potential of floricultural plants and is also a subject of fundamental biological interest. Transposon insertion or excision and post-transcriptional gene-silencing are well-studied mechanisms involved when flower color patterns form. In this paper, I present a research strategy to understand the mechanisms that govern the formation of flower color patterns. First, I discuss the significance of flower color pattern-formation research and then go on to describe a research system in the following six sections: Observation of flower patterns, Comparison of pigment components, Gene expression analysis, Regulation of target gene expression, Genomic structure, and Factors that can change color pattern-formation. In these sections, reference is made to my own studies on the marginal picotee pattern of Petunia flowers. Post-transcriptional gene-silencing of the chalcone synthase gene is responsible for the formation of white tissue in the white marginal picotee pattern in Petunia flowers. The unusual genomic structure of chalcone synthase is probably related to the operation of position-specific post-transcriptional gene-silencing. In the colored marginal picotee pattern of Petunia flowers, the higher expression of flavonol synthase is a responsible for the central white tissue formation. I also provide a research perspective from which to resolve the remaining questions.

Potential of rose for phytostabilization of chromium contaminated soils

Phytoremediation of soils contaminated with heavy metals has received considerable attention in recent years. Because of the contamination of food and vegetable crops with heavy metals, greater emphasis has been given to the cultivation of floriculture plants for remediation of the contaminated soils. In the present experiment, the response of rose to soil chromium and its possible use for remediation of soils contaminated with chromium was examined. The study revealed that, the rose plant has great tolerance and stronger ability to accumulate Cr. The partitioning of Cr revealed a higher concentration of Cr in roots (1,985 μg g−1 dry wt.) followed by shoots (760 μg g−1 dry wt.). It was concluded that, rose plant has great potential to be used for phytostabilization of soils contaminated with moderate levels of chromium.

Heterologous expression of gentian MYB1R transcription factors suppresses anthocyanin pigmentation in tobacco flowers

Single-repeat MYB transcription factors, GtMYB1R1 and GtMYB1R9 , were isolated from gentian. Overexpression of these genes reduced anthocyanin accumulation in tobacco flowers, demonstrating their applicability to modification of flower color. RNA interference (RNAi) has recently been used to successfully modify flower color intensity in several plant species. In most floricultural plants, this technique requires prior isolation of target flavonoid biosynthetic genes from the same or closely related species. To overcome this limitation, we developed a simple and efficient method for reducing floral anthocyanin accumulation based on genetic engineering using novel transcription factor genes isolated from Japanese gentians. We identified two single-repeat MYB genes--GtMYB1R and GtMYB1R9--predominantly expressed in gentian petals. Transgenic tobacco plants expressing these genes were produced, and their flowers were analyzed for flavonoid components and expression of flavonoid biosynthetic genes. Transgenic tobacco plants expressing GtMYB1R1 or GtMYB1R9 exhibited significant reductions in floral anthocyanin accumulation, resulting in white-flowered phenotypes. Expression levels of chalcone isomerase (CHI), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) genes were preferentially suppressed in these transgenic tobacco flowers. A yeast two-hybrid assay demonstrated that both GtMYB1R1 and GtMYB1R9 proteins interacted with the GtbHLH1 protein, previously identified as an anthocyanin biosynthesis regulator in gentian flowers. In addition, a transient expression assay indicated that activation of the gentian GtDFR promoter by the GtMYB3-GtbHLH1 complex was partly canceled by addition of GtMYB1R1 or GtMYB1R9. These results suggest that GtMYB1R1 and GtMYB1R9 act as antagonistic transcription factors of anthocyanin biosynthesis in gentian flowers. These genes should consequently be useful for manipulating anthocyanin accumulation via genetic engineering in flowers of other floricultural plant species.

Silicon promotes shoot proliferation and shoot growth of Salvia splendens under salt stress in vitro

Silicon (Si) is known to have beneficial effects on plants especially in monocots such as rice, wheat, and sugarcane. The objective of this study was to examine the effect of Si against NaCl on axillary shoot proliferation and shoot growth of in vitro of Salvia splendens ‘Hot Jazz’, one of the important floricultural plants. In vitro study was chosen because in such controlled environment the mechanism of Si alleviation can be clearly studied without any external hindrance. Nodal explants have been cultured on the MS medium supplemented with 3.0 mg·L−1 6-benzylaminopurine (BAP) and 0.5 mg·L−1 indole-3-acetic acid (IAA) with or without 50 or 100 mM NaCl as the salt stress source and 50 or 100 mg·L−1 K2SiO3 as the Si source. Salt stress exhibited strong retardation on growth parameters such as number and length of shoots and internodes, chlorophyll content, and the fresh and dry weights of shoots. At 50 mM NaCl both 50 and 100 mg·L−1 K2SiO3 helped to overcome the salt effect and maximized the plant growth. Though the Si gave tolerance and increased growth even in the 100 mM NaCl treatment, it was not as much effective as in the 50 mM NaCl treatment. In conclusion, these results put forward an experimental evidence for further studies of Si on salinity stress in ornamental plants.

A Study on Impact of ATMA Model in Bihar

The ITD component of NATP was implemented with the financial support of World Bank in seven States, namely, Andhra Pradesh, Bihar, Himachal Pradesh, Jharkhand, Maharashtra, Orissa and Punjab from November, 1998 to June, 2005. In Bihar ATMA were started in Muzaffarpur (Yr-1999), Madhubani (Yr-2000), Munger (Yr-2001) and Patna (Yr-2002). The project focused on bottom-up planning process for technology assessment, refinement and dissemination in order to make the whole extension system demand-driven and farmer accountable. This has helped to strengthen research and extension capabilities, restructure public extension services and test new institutional arrangements for technology transfer with the involvement of all the stakeholders of Government and Non-Government agencies at the district level. The new institutional arrangements namely Technology Dissemination Management Committee (TDMC), Inter-Departmental Working Group (IDWG), State Agricultural Management and Extension Training Institute (SAMETI), Agricultural Technology Management Agency (ATMA), Farm Information and Advisory Centers (FIACs), Block Technology Team (BTTs), Farmer Advisory Committees (FACs) and Farmers’ Organizations were established, operationalized and pilot tested at national, state, district, block and village level. To operationalize this new concept in the state and to change the mindset of all the stakeholders, various HRD interventions through more than 70 workshops, seminars, trainings and exposure visits that were organized by MANAGE and state level SAMETI (BAMETI). Agricultural Technology Management Agency (ATMA) were registered as an autonomous institution and operationalized in four districts across the State. ATMA was managed by its GB headed by District Magistrate and its day to day activity by ATMA Managing Committee headed by Project Director drawn from the SAU (RAU, Bihar) and line department. Block level mechanism was set up through 69 block level Farm Information and Advisory Centers (FIACs). State Agriculture Management and Extension Training Institute (SAMETI), an autonomous institution was established and operationalized in the State. The technology validation/dissemination was made demand-driven, market-led and farmer accountable, through bottom-up, participatory planning procedures. First, PRA were carried out in each district, which resulted in Strategic Research Extension Plans (SREPs). Research-Extension-Farmer-Market linkages were strengthened in all the districts. To promote the use of IT, the line departments including KVK/ZRS at district level and FIACs at block level were equipped with computers, telephone and internet connectivity. The mass media played a very important role in creating the awareness about the reforms and replication of success stories to non project areas . For skill up gradation and capacity building of field functionaries and farmers interest groups, both HRD activities and field programs, which included demonstration of new technologies, farmers training and exposure visits, were undertaken on a massive scale by ATMAs through line departments in various fields of agriculture, horticulture, vegetables, floriculture, aromatic and medicinal plants, animal husbandry, fisheries and allied sectors, including bee keeping, vermi-compost, value added food products and market led activities. The institutional restructuring and operational reforms which included farmer participation in planning and implementation/bottom up planning process, broad based farming system approach, public-private-partnership, collaborations of different stakeholders, strengthening R-E-F linkages, mainstreaming gender concern, augmenting IT application in agriculture and extension have started addressing the identified constraints faced in technology dissemination, as envisaged in the project. Despite some hiccups and the lower than expected support from the state government the model worked due to its innovative approach i.e. autonomy and fund flow mechanism, and was able to win back the confidence of all the stakeholders including farmers, towards the system which they had lost over the years due to the general apathy of the successive government towards this sector. If this pattern of funding is changed or the state’ governments financial rule are applied the autonomy of ATMA would be compromised and then this would go the same way other similar projects have gone, downhill.

Phytoremediation ability of some floricultural plant species

Chromium (Cr) is one of the most common heavy metals affecting the soil quality which is introduced into the environment from industries such as leather tanning, electroplating and inorganic pigment (green, orange and yellow) production. The leather industry is the major source for the environmental influx of Cr. Cleaning up of the Cr contaminated sites is a challenging task. Phytoremediation is an emerging area that could be considered for the remediation of contaminated sites because of its cost effectiveness and aesthetic advantages. An experiment was therefore was conducted to study the phytoremediation ability of different floriculture plant species (calendula, chrysanthemum, aster and dahlia). In all the four plant species, Cr beyond 10 ppm was toxic to the plants resulting in a drastic reduction in growth of plants. At 25 ppm, Cr mediated mortality of the plants was observed in chrysanthemum. In calendula and dahlia the application of Cr beyond 10 ppm inhibited flowering. The data on the partitioning of Cr revealed that the highest concentration of Cr was found in the roots and was followed by shoots and flowers. Dahlia recorded the highest concentration of Cr and calendula the least. Our results suggest that, among the four floriculture plant species only calendula is a good candidate for phytoremediation of soils contaminated with low level of Cr (up to 10 ppm).

Construction of the first genetic linkage map of Japanese gentian (Gentianaceae)

BackgroundJapanese gentians (Gentiana triflora and Gentiana scabra) are amongst the most popular floricultural plants in Japan. However, genomic resources for Japanese gentians have not yet been developed, mainly because of the heterozygous genome structure conserved by outcrossing, the long juvenile period, and limited knowledge about the inheritance of important traits. In this study, we developed a genetic linkage map to improve breeding programs of Japanese gentians.ResultsEnriched simple sequence repeat (SSR) libraries from a G. triflora double haploid line yielded almost 20,000 clones using 454 pyrosequencing technology, 6.7% of which could be used to design SSR markers. To increase the number of molecular markers, we identified three putative long terminal repeat (LTR) sequences using the recently developed inter-primer binding site (iPBS) method. We also developed retrotransposon microsatellite amplified polymorphism (REMAP) markers combining retrotransposon and inter-simple sequence repeat (ISSR) markers. In addition to SSR and REMAP markers, modified amplified fragment length polymorphism (AFLP) and random amplification polymorphic DNA (RAPD) markers were developed. Using 93 BC1 progeny from G. scabra backcrossed with a G. triflora double haploid line, 19 linkage groups were constructed with a total of 263 markers (97 SSR, 97 AFLP, 39 RAPD, and 30 REMAP markers). One phenotypic trait (stem color) and 10 functional markers related to genes controlling flower color, flowering time and cold tolerance were assigned to the linkage map, confirming its utility.ConclusionsThis is the first reported genetic linkage map for Japanese gentians and for any species belonging to the family Gentianaceae. As demonstrated by mapping of functional markers and the stem color trait, our results will help to explain the genetic basis of agronomic important traits, and will be useful for marker-assisted selection in gentian breeding programs. Our map will also be an important resource for further genetic analyses such as mapping of quantitative trait loci and map-based cloning of genes in this species.

Growing floricultural crops with brackish water

In the current review we focus on the opportunity to use brackish water in the cultivation of floricultural plants, plants for which, due to their high economic value, growers have traditionally used good quality water for irrigation. Now, even for these crops the use of alternative water sources for irrigating nursery plants is needed because of the limited supplies of fresh water in many countries; understanding how saline water can be used will also enhance sustainable development in floriculture. While salt stress usually reduces plant growth, any such reduction might not be negative for ornamentals, where shoot vigour is sometime undesirable, although on flower crops salt stress can delay flowering or decrease flower quality characteristics. However, a decrease in growth rate is not enough to characterize the salt tolerance of ornamental plants, but traits like tip and marginal leaf burn, as consequence of sodium and chlorine accumulation, have to be considered for their effects on aesthetical value. With this in mind, some halophytes should be considered for floriculture because of their ability to cope with saline environments; their potential to tolerate salt is an important factor in reducing production costs. Consequently, the identification of ornamental halophytes is important for producing a commercially acceptable crop when irrigated with brackish waters. Many aspects of a plant's reaction to salt are genetically determined, so selection of suitable genotypes or breeding for salt tolerance in ornamentals are interesting options. Developing salt-tolerant floricultural crops, together with typical management practices that avoid excessive salinity stress in the root media, will provide the grower with economically and environmentally sound wastewater reuse options.

Micropropagation of Tigridia pavonia (L.f) DC-a potential floricultural plant from twin scale explants

The present study was performed to standardize an effective protocol for micropropagation of Tigridia pavonia using tissue culture. The explants were cultured on Murashige and Skoog (MS) medium supplemented with cytokinins like thidiazuron (TDZ), zeatin, kinetin and auxins such as indole-3-acetic acid (IAA), 1-naphthalene acetic acid (NAA) and indole-3-butyric acid (IBA), individually at different concentrations. Multiple shoots were obtained on MS medium containing either 2.0 mg/L TDZ or 2.0 mg/L IAA or 0.5 mg/L IBA and in the same medium for a long period (120 d) produced tiny bulbs at the base of the senescent leaves. TDZ favored only multiple shoots without roots, whereas IAA or IBA individually or in combination with TDZ produced rooted shoots. Shoots developed on MS medium supplemented with TDZ were rooted on MS medium containing either IBA or NAA at 0.5 mg/L. The plantlets were acclimatized in pots containing garden soil. Regenerated plantlets developed into normal plants. The plants showed 99% survival. The highest number of bulblets obtained in the present study represents an effective alternative to the conventional method.

Plant regeneration and stable transformation in the floricultural plant Cleome spinosa, a C3 plant closely related to the C4 plant C. gynandra

Cleome spinosa is widely used as a garden ornamental in many countries. Here we determined the optimal conditions for plant regeneration from different tissue explants grown in vitro. Induction medium containing MS salts, MS vitamins, 3% sucrose, 1 mg l⁻¹ BA, 200 mg l⁻¹ timentin, and 0.8% agar was sufficient for shoot regeneration of all the tissue explants examined, including leaf, hypocotyl, and cotyledon. Subsequently, an Agrobacterium tumefaciens-mediated method was developed to transform the vector pCHS, which carries the transgenes Petunia chalcone synthase (chs) and selection marker neomycin phosphotransferase II (nptII), into C. spinosa. From a total of 368 cotyledon explants, 13 putative transgenic lines were regenerated from selection medium supplemented with 50 mg l⁻¹ kanamycin and 200 mg l⁻¹ timentin, and transferred to the greenhouse. Genomic PCR and Southern blot analyses revealed that the nptII transgene was present in all 13 transgenic plants. Similarly, when the Petunia chs transgene was used as a probe in Southern blot analysis, single or multiple hybridization bands were detected in 12 out of the 13 transgenic plants. In addition, T₁ progeny assay from selected transformants showed that the nptII transgene can be transmitted in a Mendelian manner from transgenic parents into their progeny. This is the first report of stable transformation of the C₃ dicotyledon C. spinosa, which will facilitate functional comparison of cell-type specific genes with counterpart C₄ dicotyledon C. gynandra using transgenic approaches.

Large Flower Size: Molecular Basis and Role of Cytokinin

Large flower size is an important trait that influences the economic value of floricultural plants. Large flower size is conferred by two morphological changes i.e. increased petal number and individual petal size. Increased petal number is induced by enlargement of the floral meristem or homeotic conversion of stamens and carpels into petals. Genes regulating meristematic competence mediate enlargement of the floral meristem, while floral homeotic genes mediate the homeotic conversion of floral organs. Increased individual petal size is induced by increased cell size or cell number. Polyploidization of the nuclear genome increases petal cell size, while increased petal cell number is induced by enhanced expression of the genes involved in auxin signal transduction and cytokinin biosynthesis. In this review, the molecular mechanisms affecting flower size, elucidated mainly using model plants such as Arabidopsis, are summarized. Further, our research on the roles of cytokinin biosynthesis and signal transduction in increased flower size in petunia, induced by the single major gene Grandiflora, is discussed. Based on these results, a possible systematic breeding method for increasing flower size is discussed.

Floriculture Sustainability Research Coalition: Bringing the Latest Sustainability Research to the Industry

C onsumer interest in environmentally friendly products has increased greenhouse growers’ interest in sustainable production techniques. It is estimated that consumers would spend up to 15% more for sustainable floricultural products than conventionally produced products, and purchasers of herbaceous or floricultural plant products tend to be more eco-friendly than those who purchase woody plant materials (Behe et al., 2010; Hawkins et al., 2011). In 2008, the Floriculture Sustainability Research Coalition (FSRC) was formed to provide information regarding sustainable production techniques for growers. Forming a coalition has allowed the group to broaden our expertise to have a more meaningful impact on growers’ production practices. The FSRC began in 2008 at the National Floriculture Forum. Founding institutions include Purdue University, University of New Hampshire, Cornell University, and University of Maine. Our core purpose is to develop central sustainability themes for outreach and research programs that synergistically build on individual strengths to increase knowledge and create outreach materials that benefit our audience. Alone, it is difficult to have much of an impact on such a large topic. But, as a group, we could potentially have more impact—not only topically, but also regionally. Cornell University examines sustainable and organic fertilizer use and energy conservation, Purdue University provides expertise in sustainable lighting and energy conservation, University of New Hampshire specializes in nonchemical growth regulation and sustainable fertilizer use, and at University of Maine, research focuses on water conservation and organic substrates and fertilizers. Over the past 3 years, the FSRC has provided research-based information to help growers produce floricultural crops more sustainably. Recent initiatives have included exploring techniques for sustainably heating greenhouses, reducing plant stretch without the use of chemical growth retardants, and developing protocols for using organic fertilizers. Conserving energy is a priority for greenhouse growers throughout the United States. A survey of greenhouse growers indicates that 55% of growers are currently using energy conservation practices; an additional 8% would like to conserve energy (Dennis et al., 2010). Our group has published several articles on novel techniques to reduce energy. For example, Lopez and Krug (2009) reported that growing medium-vigor poinsettia (Euphorbia pulcherrima) cultivars at a temperature 10 F less than recommended (75/ 67 F day/night) does not reduce crop quality for some cultivars, including ‘Freedom Red’. But, this reduction in temperature set points in the fall would reduce fuel usage for greenhouse growers. At Cornell, bedding plants including ‘Safari Orange’ marigold (Tagetes patula), ‘Delta Formula Mix’ pansy (Viola ·wittrockiana), ‘Dreams Midnight’ petunia (Petunia ·hybrida), ‘Montego Mix’ snapdragon (Antirrhinum majus), and ‘Dreamland Mix’ zinnia (Zinnia elegans) were grown in an unheated high tunnel. Compared with the heated greenhouse environment, temperatures in the high tunnel were 5 F cooler (Table 1). Pansy plants did not finish significantly later in the high tunnel compared with the greenhouse; the other plants finished about 1 week later in the high tunnel. Part of our efforts in this area has focused on extension and outreach to support growers who are transitioning to more sustainable heating technologies. In trade publications, we have highlighted innovative growers who may inspire others by example (Burnett et al., 2010). Currently, Purdue University, in collaboration with Michigan State University, University of Arizona, and Rutgers University, isworkingonaU.S.Department of Agriculture (USDA) Specialty Crops Research Initiative grant to develop light-emitting diodes as supplemental and photoperiodic lighting for greenhouses. Another highlight of our work with sustainable production has focused on finding alternatives to chemical growth retardants. Our approach to reducing plant stretch without chemical growth retardants has been to recommend that growers adjust the greenhouse or plant environment. R. Lopez and B. Krug have represented our group to growers nationally and regionally. Some techniques we have successfully used include reducing water to reduce turgor in a controlled manner. Using new moisture sensors, plants may be grown in substrates that are maintained at constant moisture contents. So, they may be grown in relatively dry substrates (volumetric water content = 15% to 25% in a peatlite mix) without risking plant damage. This may reduce plant height, but controlled drought also reduces branching (Burnett and van Iersel, 2008). One straightforward way to reduce elongation is simply to grow plants at the appropriate light level. This will reduce plant stretch by minimizing shading, particularly from neighboring plants.

Generation of serrated and wavy petals by inhibition of the activity of TCP transcription factors in Arabidopsis thaliana

The final shape of shoot lateral organs, namely, leaves and flowers, is determined by coordinated growth after the initiation of primordia from shoot meristems in seed plants. This coordination is achieved by the complex action of many transcription factors, which include the TEOSINTE BRANCHED1, CYCLOIDEA, and PCF (TCP) family. We have recently reported that CINCINNATA-like (CIN-like) TCP genes act dose-dependently to regulate the flat and smooth morphology of leaves in Arabidopsis thaliana. In contrast, the roles of CIN-like TCP genes in flower development are poorly understood. In this report, using multiple tcp mutants and transgenic plants in which the activity of CIN-like TCP transcription factors is dominantly inhibited, we found that these TCPs regulate the smooth and flat morphology of petals. Based on these findings, we discuss a possible strategy to generate a fringed morphology in floricultural plants.

Efficient production of novel floral traits in torenia by collective transformation with chimeric repressors of Arabidopsis transcription factors

Molecular breeding with genetic modification enables the production of novel floral traits in floricultural plants that could not be obtained by traditional breeding. To facilitate novel flower production, we collectively introduced 2 sets of 42 and 50 chimeric repressors of Arabidopsis transcription factors into Agrobacterium and then used these to co-transform torenia (Torenia fournieri). We generated 750 transgenic torenias, and identification of the transgenes revealed that more than 80% of the transgenic torenias had a single transgene. A total of 264 plants showed phenotypic modification, and 91.2% displayed modified flower colors and/or shapes, such as altered color patterns, curled petal margins, and wavy petals. These results indicated that the collective transformation system can be applied to molecular breeding of flowers. Detailed analysis of the phenotypes revealed that PETAL LOSS could control blotch sizes and that modification of cell shape could change the texture of petals. We found that the chimeric repressors of functionally unknown transcription factors also induced novel floral traits, and therefore, the transgenic torenias provide an understanding of the functions of transcription factors that could not be revealed by previous studies in Arabidopsis.

Beyond the blue rose: Modification of floral architecture with plant-specific chimeric repressors

There is a significant difference between cereal crops and floricultural crops in the concept of genetic modification. This is due to the difference in requirements for these agricultural products; wide variation of flower color, shape and fragrance for floricultural plants in contrast to productivity improvements or fine-tuning of physiological traits for crop plants. Bringing GM flowers to the market against their short product life involves the following factors: (1) a high-efficiency production and screening system of elite lines, (2) reliable methods to minimize biodiversity impact and evaluation of their efficacy, and (3) social receptivity based on intensive education and information sharing. We have developed an efficient system by merging the genetic information resources of the Arabidopsis genome and a transcription factor-based gene silencing system called CRES-T through the Flower CRES-T Project. In this project, we have demonstrated the applicability and general versatility of CRES-T in various plant species through experiments on eight different flower species with over 100 transcription factors. In addition to providing phenotypic information via the original database, we are attempting to improve public knowledge, for example, through the production of resin-embedded specimens of GM-flowers and reviving lost garden varieties of morning glory and using them in educational programs, to gain public acceptance of GM plants. Multi-petal cyclamens with complete sterility, which have been produced by suppressing a pair of floral-organ identity genes, will be released in the near future as the third GM commodity following Suntory's blue carnations and rose. This cyclamen represents the best example of a GM product with a low diversity impact ever produced.

Development of Simple Sequence Repeat Markers for Identification of Japanese Gentian Cultivars

Japanese cultivated gentians (Gentiana triflora, G. scabra and their hybrids) are economically important floricultural plants and their use is growing annually worldwide. We isolated 48 simple sequence repeat (SSR) markers using a SSR-enriched genomic library constructed from a gentian double haploid (DH) line. We demonstrated the utility of these SSR markers as a molecular tool for identification of vegetative-propagated gentian cultivars that are difficult to distinguish from their morphology. Five SSR loci showed high genetic polymorphism among 12 Japanese gentian cultivars, ranging from five to eight alleles per locus, with expected heterozygosity between 0.656 and 0.826, and enabled simple and precise identification of cultivars. It was confirmed that the markers were suitable to estimate genetic similarity among cultivars and were also applicable to ten related Gentiana species. This is the first report of the development of a comprehensive set of SSR markers in Japanese cultivated gentians to facilitate genomic analyses in Gentiana, including species of economic importance.