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The genus Paeonia L. includes both popular ornamental and medicinal plants with a rich history of cultivation and breeding. Breeding is an important process of increasing the diversity of the assortment and creating new cultivars of peonies with various economically important characteristics, such as the shape and color of flowers, different flowering periods and resistance to diseases and abiotic stressors. The main methods used in the breeding of peonies are traditional methods, including intraspecific, interspecific and intersectional hybridization, however, such factors as a long reproduction cycle and the complexity of the breeding process limit the possibilities for good progress in this work. The application of methods of biotechnology and molecular genetics make the breeding process more efficient. The use of germplasm resources and hybridization will accelerate the process of creating new cultivars not only with various decorative features, but also those with high adaptability to biotic and abiotic factors and resistance to phytopathogens and diseases. This review highlights the history of domestic and foreign breeding, modern trends and methodology of peony breeding. Information is provided on the achievements and limitations that exist in the field of molecular biological study of peonies.

Manilkara zapota (L.) P. Royen is an evergreen ornamental and fruit tree distributed in tropical and subtropical regions. In 2022, a leaf spot disease was observed on M. zapota plants in Guangdong Province, China. The putative pathogen was isolated and identified based on morphology and multi-locus phylogenetic analyses of tub2, ITS, tef1-α, cal and his3. Based on morphology and phylogenetic analyses, the causal agent was identified as a novel species namely Diaporthe manilkarae. Furthermore, pathogenicity essays were conducted using potted seedlings to confirm the pathogenicity. The results revealed that this fungus was able to infect wounded M. zapota leaves and develop typical symptoms similar to field symptoms whereas control and non-wounded leaves remained asymptomatic. This study will contribute to the knowledge of fungi associated with M. zapota. Further studies are required to understand the pathogenicity of this fungi on other fruit crops. [ABSTRACT FROM AUTHOR]

Weeds are undesirable plants that can interfere with human activities and can hamper crop production and practices. The competition among ornamentals and weeds for space, nutrition, light, and moisture within a restricted area, such as in container production, can be intense and destructive. In response to increasing concerns regarding herbicide injuries and the effects of pesticide use on the environment, many growers are extremely interested in non-chemical pest-management approaches. There are various non-chemical strategies to control weeds in containers, which include scouting, sanitation practices, hand weeding, mulching, irrigation management, substrate stratification, mulch discs or geo discs, lid bags, and fertilizer placement. In a restricted growth environment, weeds have been shown to reduce crop growth significantly. Limited information is available on the effects of weed densities and container sizes on ornament–weed competition within containerized production and how the concepts of fertilizer placement can be used efficiently to control weeds in containers without using any herbicides on the ornamentals. There is an immediate need to evaluate the interference and competitive effects of pernicious weed species in container-grown ornamentals in the North Central United States and to develop effective non-chemical weed control strategies by altering fertilizer placement in container production. [ABSTRACT FROM AUTHOR]

Floriculture is one of the most promising sectors of the horticulture industry with immense aesthetic, social, medicinal and economic value. Ornamentals are rich in natural pigments and they belong to diverse groups with distinct biochemical pathways. Recently, genome editing has gained significant attention owing to its potential in modifying the traits in plants. Development of in vitro transformation protocols coupled with availability of gene sequences for commercial traits could accelerate the improvement of cut flowers, particularly, chrysanthemum, rose, lily, freesia, gerbera, tulip, carnation, alstroemeria, hydrangea and lisianthus. In this review, we discussed about basic mechanism of clustered regularly interspaced short palindromic repeats–CRISPR-associated (CRISPR-Cas) systems, its types and its potential in accelerating breeding programmes for improvement of ornamental crops. [ABSTRACT FROM AUTHOR]

The cut flower industry has a global reach as flowers are often produced in countries around the equator and transported by plane or ship (reefer) mostly to the global north. Vase-life issues are often regarded as linked to only postharvest conditions while cultivation factors are just as important. Here, we review the main causes for quality reduction in cut flowers with the emphasis on the importance of preharvest conditions. Cut flower quality is characterised by a wide range of features, such as flower number, size, shape, colour (patterns), fragrance, uniformity of blooming, leaf and stem colour, plant shape and developmental stage, and absence of pests and diseases. Postharvest performance involves improving and preserving most of these characteristics for as long as possible. The main causes for cut flower quality loss are reduced water balance or carbohydrate availability, senescence and pest and diseases. Although there is a clear role for genotype, cultivation conditions are just as important to improve vase life. The role of growth conditions has been shown to be essential; irrigation, air humidity, and light quantity and quality can be used to increase quality. For example, xylem architecture is affected by the irrigation scheme, and the relative humidity in the greenhouse affects stomatal function. Both features determine the water balance of the flowering stem. Light quality and period drives photosynthesis, which is directly responsible for accumulation of carbohydrates. The carbohydrate status is important for respiration, and many senescence related processes. High carbohydrates can lead to sugar loss into the vase water, leading to bacterial growth and potential xylem blockage. Finally, inferior hygiene during cultivation and temperature and humidity control during postharvest can lead to pathogen contamination. At the end of the review, we will discuss the future outlook focussing on new phenotyping tools necessary to quantify the complex interactions between cultivation factors and postharvest performance of cut flowers. [ABSTRACT FROM AUTHOR]

The cut flower industry has a global reach as flowers are often produced in countries around the equator and transported by plane or ship (reefer) mostly to the global north. Vase-life issues are often regarded as linked to only postharvest conditions while cultivation factors are just as important. Here, we review the main causes for quality reduction in cut flowers with the emphasis on the importance of preharvest conditions. Cut flower quality is characterised by a wide range of features, such as flower number, size, shape, colour (patterns), fragrance, uniformity of blooming, leaf and stem colour, plant shape and developmental stage, and absence of pests and diseases. Postharvest performance involves improving and preserving most of these characteristics for as long as possible. The main causes for cut flower quality loss are reduced water balance or carbohydrate availability, senescence and pest and diseases. Although there is a clear role for genotype, cultivation conditions are just as important to improve vase life. The role of growth conditions has been shown to be essential; irrigation, air humidity, and light quantity and quality can be used to increase quality. For example, xylem architecture is affected by the irrigation scheme, and the relative humidity in the greenhouse affects stomatal function. Both features determine the water balance of the flowering stem. Light quality and period drives photosynthesis, which is directly responsible for accumulation of carbohydrates. The carbohydrate status is important for respiration, and many senescence related processes. High carbohydrates can lead to sugar loss into the vase water, leading to bacterial growth and potential xylem blockage. Finally, inferior hygiene during cultivation and temperature and humidity control during postharvest can lead to pathogen contamination. At the end of the review, we will discuss the future outlook focussing on new phenotyping tools necessary to quantify the complex interactions between cultivation factors and postharvest performance of cut flowers.

The objective of this study was to determine how topdressing or incorporating fertilizer with stratified or mulched substrates could affect the growth of Hibiscus rosa-sinensis 'Snow Queen', a popular ornamental plant, and the growth of liverwort (Marchantia polymorpha) and bittercress (Cardamine flexuosa), two common nursery weed species. Five different substrate treatments were evaluated, which included three stratified substrates composed of pine bark screened to a small (0.63–1.27 cm), medium (≤1.90 cm), and large (0.96–1.90 cm) particle size and two industry-standard substrates that were either mulched with rice hulls or remained unmulched. All treatments were then fertilized via either topdressing or incorporating a controlled-release fertilizer (CRF). Bittercress control was highest in mulched containers, followed by those stratified using the medium pine bark, and its growth increased overall in topdressed vs. incorporated containers regardless of substrate or mulch treatment. All the stratification treatments resulted in a decrease in liverwort coverage compared to the industry standard treatment, but topdressing generally increased liverwort coverage compared with incorporating fertilizer. In conclusion, both topdressing and incorporation appear to be compatible with fertilizer placement methods with substrate stratification from a crop production standpoint; however, weed growth may increase if fertilizer is topdressed. [ABSTRACT FROM AUTHOR]

Ornamental plants are widespread and popular all over the world. Floriculture industry is of significant economic importance for some countries. Favorable prospects for the development of industrial floriculture were also noted for Russia. This can be facilitated by CRISPR/Cas, a breakthrough method of editing genes responsible for economically valuable traits of plants, which allows bypassing the limitations of the potential intraspecific variability of plants and solving the problem of obtaining non-transgenic modified plants. This article analyzes the current status of ornamental crop breeding using the CRISPR/Cas genetic editing method. The articles were selected from the Scopus database. A search encompassing 50 most common ornamental crops yielded the total of 26 articles on genetic editing using the CRISPR/Cas system, in particular: 8 articles featuring petunia; 1 per each crop on chrysanthemum, kalanchoe, poinsettia and tobacco; 2 per each on dendrobium, gentian, lily and torenia, and 3 per each on phalaenopsis and ipomoea. The found articles were divided into three groups. The first group includes works devoted to studies of mechanisms of genes controlling useful traits, as well as the optimization of the CRISPR/Cas method for a particular crop. The second group unites works aimed at modifying color of flowers and leaves. The third group includes works on increasing the life span of a flower and obtaining double flowers. The review offers the works on the optimization of gene editing in representatives of the orchid family Orchidaceae Juss. Also, it notes the prospects of gene editing by the CRISPR/Cas system, which can accelerate qualitative improvements in breeding and raise it effectiveness, it being especially important in present conditions.

Plants with ornamental value, processing typical value of lovely flowers, and uniformity in their structure are designated as 'ornamental plants'. China is noted as 'mother of garden' and has copious resources for ornamental plants. With the use of rigorous whole genome sequencing technology, it is possible to study the evolutionary process, variations in the genome level, gene regulation, and compelling biological systems. The advancement in genomic techniques has been very slow for a long time because of the nature of enormous genetic diversity and the high cost of sequencing. Based on the new genome sequencing technologies and reduced cost of sequencing, more than sixty-nine ornamental plants have been sequenced since the first sequenced ornamental crop 'Prunus mumes' was in 2012. In this review, we have covered whole genome sequencing and resequencing techniques of ornamental crops. Also discussed the essential findings of whole genome sequencing information and its potential applications. [ABSTRACT FROM AUTHOR]

Weeds are undesirable plants that can interfere with human activities and can hamper crop production and practices. The competition among ornamentals and weeds for space, nutrition, light, and moisture within a restricted area, such as in container production, can be intense and destructive. In response to increasing concerns regarding herbicide injuries and the effects of pesticide use on the environment, many growers are extremely interested in non-chemical pest-management approaches. There are various non-chemical strategies to control weeds in containers, which include scouting, sanitation practices, hand weeding, mulching, irrigation management, substrate stratification, mulch discs or geo discs, lid bags, and fertilizer placement. In a restricted growth environment, weeds have been shown to reduce crop growth significantly. Limited information is available on the effects of weed densities and container sizes on ornament–weed competition within containerized production and how the concepts of fertilizer placement can be used efficiently to control weeds in containers without using any herbicides on the ornamentals. There is an immediate need to evaluate the interference and competitive effects of pernicious weed species in container-grown ornamentals in the North Central United States and to develop effective non-chemical weed control strategies by altering fertilizer placement in container production.

Ornamental production in the United States spans an estimated 267,000 ha and uses approximately 169,000 m3 of water yearly. Ornamental growers, particularly those with air-closed systems, are interested in implementing reduced irrigation technologies such as sensor-controlled irrigation systems to improve water use efficiency in response to water scarcity. To evaluate phytobiome impacts, we utilized an Illumina metabarcoding approach to characterize changes in fungal and oomycete rhizosphere communities of commercially grown poinsettia, complementing previous studies of single-pathogen impacts. Minor reductions (from 54 to 50% volumetric water content [VWC]) did not have large effects on rhizosphere fungal community structure but shifts in plant health status (symptomatic to asymptomatic) correlated with shifts in fungal diversity and evenness, with an increased abundance of several taxa, including Plectosphaerella cucumerina and Fusarium spp., in symptomatic plants. Further reductions in irrigation (45, 35, and 25% VWC) did not affect overall fungal community composition but the lowest VWC increased the abundance of potential root rot pathogens such as Phoma multirostrata and Plectosphaerella cucumerina. Reduced irrigation volumes decreased oomycete diversity and abundance of several known pathogens in the Phytophthora genus. Addition of a bacterial product (Companion) with putative pathogen-suppressive and drought-tolerance enhancing effects had no influence on fungal community composition or abundance but did increase abundance of some oomycete species at 45% VWC. This study shows that adoption of reduced irrigation may have greater effects on fungal versus oomycete taxa in the system, with consistent patterns of fungal enhancement, including putative fungal pathogens and beneficial organisms, and oomycete suppression.

The objective of this study was to assess the growth of two woody ornamental plants when subjected to different levels of weed competition in four different container sizes, representing different stages of production. Ligustrum (Ligustrum lucidum W.T.Aiton) and Japanese holly (Ilex crenata Thunb.) liners were potted individually into 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. Weed coverage of 0%, 50%, and 100% in each container size was maintained by surface sowing seeds of six common nursery weed species by volume, based on media surface area in each pot. Results showed that the shoot dry weight of ligustrum at 50% and 100% weed levels was reduced by 28% and 35%, 55% and 56%, 41% and 43%, and 12% and 14% in 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. The shoot dry weight of Japanese holly at 50% and 100% weed levels was reduced by 18% and 22%, 51% and 52%, 51% and 53%, and 40% and 53% in 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. Results indicate that weed competition at 50% and 100% weed level was similar across all four container sizes, and weeds remained competitive even in the larger container sizes. [ABSTRACT FROM AUTHOR]

The breeding of ornamental plants as a branch of crop production is an integral part of the set of measures aimed at obtaining a wide range of different plants with high decorative characteristics. The main objective of this branch is the creation of plants that are attractive to the consumer and commercially characterized by such valuable biological features as adaptability, resistance to diseases, pests, frost and others. Most ornamental plant varieties were bred by means of traditional breeding methods such as selection, distant hybridization, clone breeding, radiation and chemically induced mutagenesis. However, the use of traditional breeding tools is limited by the potential for intraspecific variability. The development of modern biotechnological and genetic approaches to the breeding of new varieties has made it possible to modify the plant genotype at a qualitatively new level. The present review covers the directions in and methodology of modern ornamental plant breeding in Russia, ways of mobilizing the genetic resources of the main ornamental crops such as rose, clematis, canna, chrysanthemum, pelargonia, iris, daylily, tulip, lilac, and rhododendron. Aslo, the review offers examples of ornamental plant breeding work uderway in the leading specialized scientific institutions such as the Russian State Agrarian University – the K.A. Timiryazev Moscow Agricultural Academy, I.V. Michurin Federal Research Centre, Nikitsky Botanical Gardens – National Scientific Center of the RAS, Subtropical Scientific Center of the Russian Academy of Sciences, Botanical Garden of the M.V. Lomonosov Moscow State University, All-Russian Scientific Research Institute of Tobacco, Mahorka and Tobacco Products. The world and Russian flower and ornamental plants markets, the problem and methods of resolving the issue of quality import substitution, and prospects for the development of floriculture in Russia in the foreseeable future are also briefly considered.

The objective of this study was to determine how topdressing or incorporating fertilizer with stratified or mulched substrates could affect the growth of Hibiscus rosa-sinensis ‘Snow Queen’, a popular ornamental plant, and the growth of liverwort (Marchantia polymorpha) and bittercress (Cardamine flexuosa), two common nursery weed species. Five different substrate treatments were evaluated, which included three stratified substrates composed of pine bark screened to a small (0.63–1.27 cm), medium (≤1.90 cm), and large (0.96–1.90 cm) particle size and two industry-standard substrates that were either mulched with rice hulls or remained unmulched. All treatments were then fertilized via either topdressing or incorporating a controlled-release fertilizer (CRF). Bittercress control was highest in mulched containers, followed by those stratified using the medium pine bark, and its growth increased overall in topdressed vs. incorporated containers regardless of substrate or mulch treatment. All the stratification treatments resulted in a decrease in liverwort coverage compared to the industry standard treatment, but topdressing generally increased liverwort coverage compared with incorporating fertilizer. In conclusion, both topdressing and incorporation appear to be compatible with fertilizer placement methods with substrate stratification from a crop production standpoint; however, weed growth may increase if fertilizer is topdressed.

Plant pathogens evade basal defense systems and attack different organs and tissues of plants. Genetic engineering of plants with genes that confer resistance against pathogens is very effective in pathogen control. Conventional breeding for disease resistance in ornamental crops is difficult and lagging relative to that in non-ornamental crops due to an inadequate number of disease-resistant genes. Therefore, genetic engineering of these plants with defense-conferring genes is a practical approach. We used rice BSR2 encoding CYP78A15 for developing transgenic Torenia fournieri Lind. lines. The overexpression of BSR2 conferred resistance against two devastating fungal pathogens, Rhizoctonia solani and Botrytis cinerea. In addition, BSR2 overexpression resulted in enlarged flowers with enlarged floral organs. Histological observation of the petal cells suggested that the enlargement in the floral organs could be due to the elongation and expansion of the cells. Therefore, the overexpression of BSR2 confers broad-spectrum disease resistance and induces the production of enlarged flowers simultaneously. Therefore, this could be an effective strategy for developing ornamental crops that are disease-resistant and economically more valuable. [ABSTRACT FROM AUTHOR]

Pollinators are attracted to vibrant flower colors. That is why flower color is the key agent to allow successful fruit set in food or ornamental crops. However, black flower color is the least attractive to pollinators, although a number of plant species produce black flowers. Cyanidin-based anthocyanins are thought to be the key agents to induce black color in the ornamental and fruit crops. R2R3-MYB transcription factors (TFs) play key roles for the tissue-specific accumulation of anthocyanin. MYB1 and MYB11 are the key TFs regulating the expression of anthocyanin biosynthesis genes for black color accumulation. Post-transcriptional silencing of flavone synthase II (FNS) gene is the technological method to stimulate the accumulation of cyanidin-based anthocyanins in black cultivars. Type 1 promoter of DvIVS takes the advantage of FNS silencing to produce large amounts of black anthocyanins. Exogenous ethylene application triggers anthocyanin accumulation in the fruit skin at ripening. Environment cues have been the pivotal regulators to allow differential accumulation of anthocyanins to regulate black color. Heat stress is one of the most important environmental stimulus that regulates concentration gradient of anthocyanins in various plant parts, thereby affecting the color pattern of flowers. Stability of black anthocyanins in the extreme environments can save the damage, especially in fruits, caused by abiotic stress. White flowers without anthocyanin face more damages from abiotic stress than dark color flowers. The intensity and pattern of flower color accumulation determine the overall fruit set, thereby controlling crop yield and human food needs. This review paper presents comprehensive knowledge of black flower regulation as affected by high temperature stress, and the molecular regulators of anthocyanin for black color in ornamental and food crops. It also discusses the black color-pollination interaction pattern affected by heat stress for food and ornamental crops. [ABSTRACT FROM AUTHOR]

Pollinators are attracted to vibrant flower colors. That is why flower color is the key agent to allow successful fruit set in food or ornamental crops. However, black flower color is the least attractive to pollinators, although a number of plant species produce black flowers. Cyanidin-based anthocyanins are thought to be the key agents to induce black color in the ornamental and fruit crops. R2R3-MYB transcription factors (TFs) play key roles for the tissue-specific accumulation of anthocyanin. MYB1 and MYB11 are the key TFs regulating the expression of anthocyanin biosynthesis genes for black color accumulation. Post-transcriptional silencing of flavone synthase II (FNS) gene is the technological method to stimulate the accumulation of cyanidin-based anthocyanins in black cultivars. Type 1 promoter of DvIVS takes the advantage of FNS silencing to produce large amounts of black anthocyanins. Exogenous ethylene application triggers anthocyanin accumulation in the fruit skin at ripening. Environment cues have been the pivotal regulators to allow differential accumulation of anthocyanins to regulate black color. Heat stress is one of the most important environmental stimulus that regulates concentration gradient of anthocyanins in various plant parts, thereby affecting the color pattern of flowers. Stability of black anthocyanins in the extreme environments can save the damage, especially in fruits, caused by abiotic stress. White flowers without anthocyanin face more damages from abiotic stress than dark color flowers. The intensity and pattern of flower color accumulation determine the overall fruit set, thereby controlling crop yield and human food needs. This review paper presents comprehensive knowledge of black flower regulation as affected by high temperature stress, and the molecular regulators of anthocyanin for black color in ornamental and food crops. It also discusses the black color-pollination interaction pattern affected by heat stress for food and ornamental crops.

Gerbera (Gerbera jamesonii L.) has its immense importance to the floriculture industry worldwide. The gerbera flower production has been hampered by various viruses, among them cucumber mosaic virus (CMV) has shown considerable damage. As natural resistance to CMV is absent in gerbera, here, we have made an attempt to develop transgenic gerbera plants expressing coat protein (CP) gene of CMV via Agrobacterium mediated transformation of base petiole explants for genetic resistance to CMV infection. Among the 44 putative transgenic gerbera plant acclimatized, 39 were found positive for integration of CP gene by polymerase chain reaction and southern hybridization assay using their specific primer and probe respectively. Northern hybridization assay using CP gene specific probe confirmed the transcription of transgene in all 39 transgenic plants. These plants showed translation of CP during DAS-ELISA when tested with antiserum specific to CP of CMV. These 39 plants when challenged by mechanical inoculations with CMV gerbera isolate showed virus resistance in 53% (21 out of 39) plants, virus tolerance (delayed mild symptom) in 33% (13/39) plants, while rest 12.8% (5/39) plants showed severe disease symptoms. The CP mediated resistance of CMV in transgenic gerbera is being reported for the first time from India. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the growth of two woody ornamental plants when subjected to different levels of weed competition in four different container sizes, representing different stages of production. Ligustrum (Ligustrum lucidum W.T.Aiton) and Japanese holly (Ilex crenata Thunb.) liners were potted individually into 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. Weed coverage of 0%, 50%, and 100% in each container size was maintained by surface sowing seeds of six common nursery weed species by volume, based on media surface area in each pot. Results showed that the shoot dry weight of ligustrum at 50% and 100% weed levels was reduced by 28% and 35%, 55% and 56%, 41% and 43%, and 12% and 14% in 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. The shoot dry weight of Japanese holly at 50% and 100% weed levels was reduced by 18% and 22%, 51% and 52%, 51% and 53%, and 40% and 53% in 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. Results indicate that weed competition at 50% and 100% weed level was similar across all four container sizes, and weeds remained competitive even in the larger container sizes.

This paper reviews the global status of phytoplasma disease associated with different ornamental crops. This paper investigated phytoplasmas, an equally important group of pathogens that severely harm the growth and marketing properties of ornamental plants, lowering their commercial worth. In this paper, number of ornamental plants was found to be infected with 'Ca. Phytoplasma' species and treatment techniques were adapted using tetracycline insecticides for elimination and emission of phytoplasmas. [ABSTRACT FROM AUTHOR]

A profile of the hibiscus bud weevil intended for the use of interested laypersons with some knowledge of biology as well as academic audiences. The hibiscus bud weevil, a pest of China rose hibiscus, originates from northeastern Mexico and southern Texas and can cause large economic losses to hibiscus growers. This fact sheet provides nursery owners, homeowners, and other interested people with information on this serious pest.

Key message: We review the main genes underlying commercial traits in cut flower species and critically discuss the possibility to apply genome editing approaches to produce novel variation and phenotypes. Promoting flowering and flower longevity as well as creating novelty in flower structure, colour range and fragrances are major objectives of ornamental plant breeding. The novel genome editing techniques add new possibilities to study gene function and breed new varieties. The implementation of such techniques, however, relies on detailed information about structure and function of genomes and genes. Moreover, improved protocols for efficient delivery of editing reagents are required. Recent results of the application of genome editing techniques to elite ornamental crops are discussed in this review. Enabling technologies and genomic resources are reviewed in relation to the implementation of such approaches. Availability of the main gene sequences, underlying commercial traits and in vitro transformation protocols are provided for the world's best-selling cut flowers, namely rose, lily, chrysanthemum, lisianthus, tulip, gerbera, freesia, alstroemeria, carnation and hydrangea. Results obtained so far are described and their implications for the improvement of flowering, flower architecture, colour, scent and shelf-life are discussed. [ABSTRACT FROM AUTHOR]

The scheduling of plant production is a critical aspect in modern floriculture since nowadays, sales are not oriented toward the recurring holidays as in the past, but always more toward impulse buying, implying a more diverse and constant demand on the market. This requires continuous production, often regulated by precise commercial agreements between growers and buyers, and between buyers and dealers, particularly in large-scale retail trade. In this scenario, diverse techniques to modulate the duration of the growing cycle, by hastening or slowing down plant growth and development, have been developed to match plant flowering to the market demand. Among the numerous approaches, the manipulation of climatic parameters in the growth environment is one of the most common in greenhouse floriculture. In this review, we summarize the physiological and biochemical bases underlying the main mechanisms of flowering, depending on the plant reaction to endogenous signals or environmental stimuli. In addition, the strategies based on the control of temperature (before or after planting) and light environment (as light intensity and spectrum, and the photoperiod) in the scheduling of flower and ornamental crop production are briefly described.

Bemisia tabaci is a key pest of horticultural, fibre and ornamental crops worldwide, primarily as a vector of plant viruses. In Italy, B. tabaci has established since the 1980s–1990s in southern regions as well as in Sicily and Sardinia. Recent reports of infestations in some areas of central Italy prompted a new survey to assess the whitefly distribution in the country as well as to update the species and haplotype composition of the populations present in southern Italy and in the main islands. The survey confirmed that B. tabaci is nowadays established in central Italy even at more northern latitudes than those noticed before. Most of the specimens collected throughout the country belonged to the Mediterranean (MED) species. The MEDQ1 and Q2 haplogroups were prevailing in open-field and greenhouse cultivations, respectively, except in Sardinia where only Q1 specimens were found on a wide range of crops and weeds. Population genetics analyses showed that several MEDQ1 haplotypes currently occur in Italy and their distribution is unrelated to evident temporal and geographic trends, except for a new genetic variant which seems to have originated in Sardinia. The MED species is known to better adapt to insecticide treatments and high temperatures, and its northward spread in Italy may have been favoured by the intensive agricultural practices and steady increase in both winter and summer temperatures occurring in the last few decades. The extensive presence of B. tabaci in Italy proves that a strict surveillance for possible new outbreaks of whitefly-transmitted viruses should be addressed to a range of sites that are expanding northwards.

Characterization of genetic diversity in germplasm collections requires an efficient set of molecular markers. We assessed the efficiency of 36 new SCoT markers, 10 new ISSR markers, and 5 microsatellites for the characterization of genetic diversity in chrysanthemum core collection of 95 accessions (Russian and foreign cultivars). Seven new SCoT (SCoT12, 20, 21, 23, 29, 31, 34) and six new ISSR markers ((GA)8T, (CT)8G, (CTTCA)3, (GGAGA)3, (TC)8C, (CT)8TG) were efficient for the genetic diversity analysis in Chrysanthemum × morifolium collection. After STRUCTURE analysis, most Russian cultivars showed 20–50% of genetic admixtures of the foreign cultivars. Neighbor joining analysis based on the combination of SSR, ISSR, and SCoT data showed the best accordance with phenotype and origin compared to the separate analysis by each marker type. The position of the accessions within the phylogenetic tree corresponded with the origin and with some important traits, namely, plant height, stem and peduncle thickness, inflorescence type, composite flower and floret types, flower color, and disc color. In addition, several SCoT markers were suitable to separate the groups distinctly by the phenotypical traits such as plant height (SCoT29, SCoT34), thickness of the stem and peduncle (SCoT31, SCoT34), and leaf size and the floret type (SCoT31). These results provide new findings for the selection of markers associated with important traits in Chrysanthemum for trait-oriented breeding and germplasm characterization.

Recently, the distribution of seeds and seedlings has expanded worldwide due to the internationalization of agricultural products. Quarantine-notifiable plant pathogens including viroids are therefore spreading globally, which is a major concern in terms of plant protection. Viroids are the smallest known plant pathogen and have a large host range, causing various disease symptoms after infection. In 2011, the Potato spindle tuber viroid (PSTVd), belonging to the Pospiviroid family, was detected in Akita Prefecture (North Japan). By 2015, unregistered PSTVd isolates had been identified in seven dahlia cultivars (a total of about 5000 plants) when leaves were surveyed in the fields where PSTVd was first detected. The newly discovered PSTVd isolates are very similar to a PSTVd dahlia isolate that was found previously in Japan. None of the infected dahlias showed disease symptoms during the early stages of infection, however, growth suppression occasionally occurred during later stages. At present, PSTVd appears to have been successfully eradicated from Akita prefecture, but the threat of new PSTVd isolates spreading to other susceptible hosts, such as tomatoes and potatoes, still remains. [ABSTRACT FROM AUTHOR]

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Flowers are grown not only for their ornamental values but also for the nutritive, medicinal, culinary, cosmetic and aromatic properties. They are a rich source of many chemical compounds which play an important role in various metabolic processes in the human body. Among them are minerals. The aim of the study, conducted in 2014-2015, was to determine and compare the content of macro- (N, P, K, Na, Ca, Mg, S), microelements (Fe, Zn, Cu, Mn) and heavy metals (Ni, Pb, Co, Cd) in flowers of different species and cultivars of ornamental plants. The experimental material consisted of dried flowers of Mimulus × hybridus L. (Magic Yellow, Magic Red), Antirrhinum majus L. (Cavalier), Dianthus chinensis L. (Chianti), Hemerocallis × hybrida Hort., Paeonia officinalis L. (Sarah Bernardt, Dr Aleksander Fleming, Karl Rosenfield), Monarda didyma L., Monarda fistulosa L. and Monarda citriodora subsp. austromontana Cerv. ex Lag. (Bees Favourite). The content of nitrogen was assessed by the Kjeldahls method, phosphorus - by the colorimetric method, potassium, sodium - by the flame photometry method, calcium, magnesium, sulphur, iron, zinc, copper, manganese, nickel, lead, cobalt and cadmium - by the method of atomic absorption spectrophotometry (AAS). The results of the chemical analyses showed that Monarda and Mimulus × hybridus L. flowers were characterised by a significantly higher content of macro- and microelements in comparison with the other species. Among the macroelements, the highest amounts were noted for potassium (on average 30.03 g kg-1 d.m.), and from microelements - for iron (on average 154.93 mg kg-1 d.m.). Moreover, the edible flower species were characterised by a relatively low concentration of heavy metals: 2.297 mg Ni, 1.298 mg Pb, 0.723 mg Co and 0.342 mg Cd per kg of dry matter on average. The lowest amounts of heavy metals were found in flowers of Paeonia officinalis L. cultivars. [ABSTRACT FROM AUTHOR]

This study gathers information about the effects of different extracts (methanol and water) from rhizomes and aerial parts of Iris schachtii on selected enzymes (cholinesterases, alpha-amylase and alpha-glucosidase, tyrosinase and lipase) as well as of their antioxidant capacities and antimutagenic properties in relation with their phenolic composition. The chemical composition was assessed by determining total phenolic and flavonoid content as well as individual phenolic compounds by HPLC-DAD. Moreover, antioxidant abilities of the investigated extracts were tested by using different assays including free radical scavenging (DPPH and ABTS), reducing power (CUPRAC and FRAP), phosphomolybdenum and metal chelating, overall rhizomes being indicated as a superior source of antioxidant compounds. HPLC analysis revealed the abundance of some phenolics including apigenin (2584 μg/g extract) and luteolin (2510 μg/g extract) in aerial parts extracts while rhizomes were rich in apigenin (4734 μg/g extract) and kaempferol (4214 μg/g extract). The methanolic extracts exhibited a high anti-lipase activity while all extracts presented a relatively high inhibition on α-glucosidase. Furthermore, interactions between dominant compounds from extracts and selected enzymes were investigated by molecular modeling studies in order to explain at a molecular level the interactions between selected compounds and active sites of the enzyme/s. [ABSTRACT FROM AUTHOR]

• Abiotic stresses affecting ornamental crops have been summarized. • Major biotechnological interventions for combating abiotic stresses have been reviewed. • Work done in major ornamental crops related to abiotic stress tolerance has been highlighted. Biotechnology with the use of genetic engineering tools constitutes different applications in improving crop plants including commercial flower crops and several other ornamental plants. Competition for excellent quality has compelled the research endeavours towards the use of molecular markers, functional genomics, and genetic engineering in ornamental crop breeding where potential genes have been identified and several traits have been improved. AREB/ABF TFs, AP2/ERF , NAC TFs, bZIP TFs, MYC, and MYB have been implicated in drought stress response. CBF genes encode AP2/ERF (APETALA2 /Ethylene-Responsive Factor) transcription factors to initiate cold stress responses in plants. Genes such as Na+/H+ antiporter genes (AtNHX1, AtSOS1), DREB1A, SOS1, ICE1, WRKY4, NAC1, SOS3, etc. have been identified for imparting salt tolerance in flower crops. Heat shock transcription factors (HSFs) mediate the expression of heat shock protein, where several genes have been shown to impart heat tolerance such as; HSP70, FaHsfA2c, etc. This review covers the work on gene identification and developing stress- responsive transgenics in commercial flower crops and other ornamental plants. [ABSTRACT FROM AUTHOR]

This paper aims to assess the concentration of heavy metals (Fe, Zn, Cu, Pb, Cr, Ni and Co) in leaves and flowers of four fragrant Rosa species irrigated with treated and untreated wastewater. Analysis of irrigation water showed that all minerals and chemicals were in permissible level in canal water and treated wastewater whereas untreated wastewater contained higher electrical conductivity (EC), biological oxygen demand (BOD), chemical oxygen demand (COD) and metals like Cd, Co, Cu and Pb. Results of experiment showed that all metals were in acceptable range recommended by World Health Organisation (WHO) except Cr and Ni. Chromium level was high than permissible limits in Rosa species under all irrigations in leaves and flowers. Ni contents were high in leaves and flowers under untreated and treated wastewater respectively in Rosa species (except Rosa Gruss-an-teplitz) during 2nd year of experiment. This study confirmed that metals contents varied from spot to spot, species to species and different parts of each species. As wastewater can efficiently increase water resources for irrigation but it is still recommended that untreated wastewater should be treated to some extent to lower down the contamination and plants should be analysed for contaminants before processing them for medicinal/food purpose or for human consumption. [ABSTRACT FROM AUTHOR]

An illustrated key for the species of Thysanoptera in ornamental crops in Central America is presented. The key includes a total of 21 species, distributed in 16 in the suborder Terebrantia and five in the suborder Tubulifera. In all cases the location of collections is indicated and when if possible also the ornamental crop which was found. [ABSTRACT FROM AUTHOR]

Development of transgenics is the need of the modern era of plant breeding, as they possess the potential to incorporate those characters in crop varieties which are either difficult or impossible through conventional breeding approaches. In case of ornamental crops, the progress made in transgenic breeding is not that impressive like in cereals, pulses and vegetables, but the initiatives taken and advancements made have implicated the bright future of this technology in ornamental crops. Improved morphology, flower colour, resistance and fragrance are some of the desired novel traits in ornamental crops where transgenic approaches need to intervene. Transgenic breeding in major cut-flower crops like rose, chrysanthemum, gladiolus and carnation has provided avenues for incorporation of novel traits in other ornamental crops as well and has made such crops an ideal target for application of other advanced technologies. [ABSTRACT FROM AUTHOR]

In 2013, potato spindle tuber viroid (PSTVd) was identified in 17 lots of seven dahlia cultivars at a single company in the Netherlands. Analysis of the genotypes showed highest identities with a PSTVd genome from dahlias in Japan. The dahlia isolate could be transferred experimentally to tomato and potato. In tomato this resulted in mild chlorosis and stunting; in potato no symptoms appeared, nor in aerial parts, nor in tubers. The infections in dahlias were eradicated by destroying all infected lots at the infested company. No infections were found in lots of the same cultivars grown by other companies. Moreover, PSTVd was not detected in any of the lots of three other companies that had bought dahlia planting material of the infested company. In 2014, PSTVd was not found in a survey including all cultivars in which PSTVd had been identified in 2013. Therefore, it was concluded that PSTVd had been eradicated in dahlias in the Netherlands. [ABSTRACT FROM AUTHOR]

BACKGROUND Spray boom systems, an alternative to the predominantly-used spray guns, have the potential to considerably improve crop protection management in glasshouses. Based on earlier experiments, the further optimization of the deposits of a medium spray quality extended range flat fan nozzle type using easy adjustable spray boom settings was examined. Using mineral chelate tracers and water sensitive papers, the spray results were monitored at three plant levels, on the upper side and the underside of the leaves, and on some off-target collectors. In addition, the deposition datasets of all tree experiments were compared. RESULTS The data showed that the most efficient spray distribution with the medium spray quality flat fan nozzles was found with a 30° forward angled spray combined with air support and an application rate of 1000 L ha-1. This technique resulted in a more uniform deposition in the dense canopy and increased spray deposition on the lower side of the leaves compared with the a standard spray boom application. Applying 1000 L ha-1 in two subsequent runs instead of one did not seem to show any added value. CONCLUSION Spray deposition can be improved hugely simply by changing some spray boom settings like nozzle type, angling the spray, using air support and adjusting the spray volume to the crop. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Bacterial leaf spot on roses caused by a Xanthomonas sp. is a new disease affecting commercial rose production with the potential to cause major economic losses. In the past few decades, antimicrobial photocatalyst technology has emerged from basic research and development to provide convenient formulations of titanium dioxide (TiO2) nanoparticles, which have the ability to destroy bacteria on surfaces in the presence of light. In this study, a TiO2 nanoparticle formulation containing zinc (TiO2/Zn) was tested for management of bacterial leaf spot on Rosa 'Noare'. TiO2/Zn caused significant reduction in the survival of Xanthomonas sp. strain Xr-1 on glass coverslips coated with the nanoparticles on exposure to light at 3 x 104 lux for 10 minutes. There was no reduction of bacterial viability in non-coated or non-illuminated controls. Field applications of TiO2/Zn at ≈500 to 800 ppm on Rosa 'Noare' significantly reduced bacterial spot severity compared with the untreated control. TiO2/Zn activity was better or on par with the ornamental industry standard for management of rose diseases. [ABSTRACT FROM AUTHOR]

Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Abstract: In Flanders, greenhouse growers predominantly use handheld sprayers instead of spray boom equipment. Nevertheless, handheld sprayers have several drawbacks. Growers increasingly recognize the advantages of spray boom equipment, which has resulted in increasing adoption of spray boom systems. Some growers still doubt the efficacy of spray boom systems, however, while others have questions about their use. In this study, we aimed to address both doubts and questions by optimizing a vertical spray boom application for a bay laurel crop using air support and spray angling. Spray deposition on the stem and the upper and lower side of the leaves was measured using mineral chelates as tracers at twenty collector positions in the top and bottom as well as in the front, back, left and right zone of the plant. Four plant repetitions were used for every spray event. Nine different application techniques were tested in three repetitions in laboratory conditions using a fully automated spray system. The effect of nozzle type, angled nozzles, air support and spraying in two passes with an opposite direction was evaluated. The experiments showed that collector position and application technique had a significant effect on deposition. However, angling the spray, using air support or spraying in two consecutive passes with an opposite direction did not result in a higher deposition or penetration capacity compared with the standard vertical spray boom. Nevertheless, some techniques might still result in a higher bio-efficacy due to a more homogenous liquid distribution. The use of a vertical spray boom is a promising technique for safe and efficient application of plant protection products in a vertical crop. Nozzle choice, spray boom setting, spray distance and the air speed of air assisted sprayers require careful consideration, however. Of the tested techniques, the applications made with an extended range standard flat fan nozzle without air support, directed straight toward the crop and used with a fixed spray distance of 30 cm to the stem generally produced the best spray results in the considered, conically pruned bay laurel crop. [Copyright &y& Elsevier]

The media temperature of containerized plants has a distinct impact on crop growth and development, water and nutrient uptake. Ultimately, it influences the marketable quality of the plant. Containerized plants suffer due to a low root zone temperature during the winter and a high root zone temperature during the summer months. Understanding the relationship between media temperature and weather conditions is the first step towards the development of strategies that could reduce crop risks associated with extreme temperatures in the root zone. The objective of this study was to determine the relationship between the media temperature (MT) and the air temperature (AT) of containerized nursery crops subjected to short irrigation intervals. The study was conducted at Monrovia Growers, located in Cairo, Georgia, USA, during the summer of 2005 and the spring and summer of 2006. Data from 2006 were used to develop various models and the data from 2005 were used for model evaluation. The experiment consisted of a 14.7-Lplastic container with five replicates. Media temperature, air temperature and solar radiation were recorded at 15-min intervals. Weather data were obtained from an automated weather station located 20 m from the experimental site. Irrigation was applied six times daily using a micro-irrigation system consisting of microsprayers (spitters). The MT gradient (ΔMT) and AT gradient (ΔAT) were determined every 2 h, from 0600 h to 2000 h, in May, June, July, and August. The investigation lasted for 10 d each month. For all 10-d periods, a significant (P<0.05) correlation between ΔAT and ΔMT was found during the day. The correlation between ΔAT and ΔMT was affected by the time lag between AT and MT. The relationship between ΔAT and ΔMT varied for different time periods during the day and for all 10-d periods that were analyzed. Our results demonstrated that media temperature and air temperature have a significant correlation. However, this correlation seems to be a function of the time of day. Specific equations were, therefore, developed for estimating ΔMT as a function of ΔAT for different time periods of the day and for different months. These equations could successfully predict media temperature as a function of air temperature for time periods of less than an hour. Further work will consider other variables, such as solar radiation, media moisture and the temperature of the irrigation water. [ABSTRACT FROM AUTHOR]

The scheduling of plant production is a critical aspect in modern floriculture since nowadays, sales are not oriented toward the recurring holidays as in the past, but always more toward impulse buying, implying a more diverse and constant demand on the market. This requires continuous production, often regulated by precise commercial agreements between growers and buyers, and between buyers and dealers, particularly in large-scale retail trade. In this scenario, diverse techniques to modulate the duration of the growing cycle, by hastening or slowing down plant growth and development, have been developed to match plant flowering to the market demand. Among the numerous approaches, the manipulation of climatic parameters in the growth environment is one of the most common in greenhouse floriculture. In this review, we summarize the physiological and biochemical bases underlying the main mechanisms of flowering, depending on the plant reaction to endogenous signals or environmental stimuli. In addition, the strategies based on the control of temperature (before or after planting) and light environment (as light intensity and spectrum, and the photoperiod) in the scheduling of flower and ornamental crop production are briefly described. [ABSTRACT FROM AUTHOR]