Saintpaulia Research Articles

First Report of Cucumber mosaic virus in Saintpaulia ionantha in Korea.

African violet (Saintpaulia ionantha) is an ornamental species of the family Gesneriaceae and is characterized by fleshy leaves and colorful flowers. This popular, exotic ornamental, originally from Kenya and Tanzania, is vegetatively produced from cutting and tissue culture (1). In May 2013, virus-like foliar symptoms, including a mosaic with dark green islands and chlorosis surrounding the veins, were observed on an African violet plant in a greenhouse located in Icheon, Korea. Cucumber mosaic virus (CMV) was identified in the symptomatic plant by serological testing for the presence of CMV coat protein (CP) with a commercial immunostrip kit (Agdia, Elkhart, IN). The presence of CMV was confirmed by serological detection with a commercially available double-antibody sandwich (DAS)-ELISA kit (Agdia). Sap from the serologically positive sample was mechanically inoculated to test plants using 10 mM phosphate buffer (pH 7.0). The virus (named CMV-AV1) caused necrotic local lesions on Chenopodium amaranticolor at 5 days post-inoculation (dpi), while mild to severe mosaic was observed in Nicotiana glutinosa, N. tabacum 'Samsun NN,' Cucurbita pepo 'Super-Top,' Physalis angulate, and Solanum lycopersicum 'Unicorn' 10 to 14 dpi. Examination of the inoculated plant leaves by DAS-ELISA and electron microscopy (leaf dips) showed positive reactions to CMV and the presence of spherical virions ∼28 nm in diameter, respectively. To verify whether CMV-AV1 is the cause of disease symptoms observed in African violet, virus-free African violet (10 plants) was mechanically inoculated by sap from local lesions on C. amaranticolor inoculated with CMV-AV1. At 8 weeks after inoculation, all plants produced systemic mosaic and chlorosis surrounding veins, resulting in strong DAS-ELISA reactions for CMV, whereas mock-inoculated African violet plants remained symptomless and virus-free. The presence of CMV-AV1 in all naturally infected and mechanically inoculated plants was further verified by reverse transcription (RT)-PCR. Total RNAs were extracted with the RNeasy Plant Mini Kit (Qiagen, Hilden, Germany), according to the manufacturer's instructions. RT-PCR was carried out with the One-Step RT-PCR Kit (Invitrogen, Carlsbad, CA) using a pair of primers, CPTALL3 and CPTALL5 (2), amplifying the entire CP gene and part of an intergenic region and 3'-noncoding region of CMV RNA3. RT-PCR products (960 bp) were obtained from all naturally infected and mechanically inoculated plants as well as from positive control (viral RNAs from virions), but not from healthy tissues. The amplified RT-PCR products were purified with QIAquick PCR Purification Kit (Qiagen) and sequenced using BigDye Termination kit (Applied Biosystems, Foster City, CA). Multiple alignment of the CMV-AV1 CP sequence (Accession No. AB842275) with CP sequences of other CMV isolates using MEGA5 software revealed that 91.8 to 99.0% and 71.0 to 73.0% identities to those of CMV subgroup I and subgroup II, respectively. These results provide additional confirmation of CMV-AV1 infection. CMV may pose a major threat for production of African violet since the farming of African violet plants is performed using the vegetative propagation of the African violet leaves in Korea. In particular, mosaic and chlorosis symptoms in African violet cause damage to ornamental quality of African violet. To our knowledge, this is the first report of CMV infection of African violet in the world.

Contribuciones del Laboratorio de Cultivo de Tejidos Vegetales de Zamorano a la Micropropagación y Propagación de Plantas Libres de Patógenos

Zamorano inauguró el Laboratorio de Cultivo de Tejidos Vegetales en 1985, durante 27 años se ha investigado sobre propagación in vitro de cultivos ornamentales, agronómicos y maderables. Entre los ornamentales más investigados está la orquídea Rhyncholaelia digbyana, flor nacional de Honduras, y varias especies nativas de la región. También se ha trabajado en violeta africana (Saintpaulia ionantha), zamias (Zamioculcas zamiifolia), helechos (Nephrolepis cordifolia) y anturios (Anthurium andreanum), cultivos apreciados en el mercado local de ornamentales y que son producto de las prácticas del aprender haciendo de nuestros estudiantes. Los últimos cuatro años se ha investigado y producido plántulas de especies económicamente importantes para la industria y la producción de energía como la caña de azúcar y el Arundo donax; para procesos de extracción de compuestos como la Stevia rebaudiana; para la exportación como malanga (Colocasia esculenta), y camote (Ipomea batatas). Se ha contribuido con los pequeños y medianos productores y exportadores de camote con aproximadamente 3000 plantas por año de camote libres de virus. DOI: http://dx.doi.org/10.5377/ceiba.v52i1.1130

<i>Dorstenia christenhuszii</i> (Moraceae), a new species from the Taita Hills, Kenya

At the Mbololo locality of the endemic African violet (Streptocarpus teitensis, Gesneriaceae) in the Taita Hills, Kenya, a new species of Dorstenia (Moraceae) was discovered. It is described here and illustrated with photographs.

Aphelenchoides bicaudatusfrom Ornamental Nurseries in Taiwan and Its Relationship with Some Agricultural Crops

Aphelenchoides bicaudatus nematodes were identified in planting materials and water samples from 35 floral ornamental nurseries in Taiwan. A pure line of the nematode was established from the bulk samples collected, and the nematode was identified as A. bicaudatus on the basis of morphometric data and the 18S gene sequence (GU984233). Host range tests were conducted by inoculating A. bicaudatus onto Phalaenopsis spp. strawberry, rice, bird's-nest fern, cyclamen, dendrobium, African violet, and saxifrage (all reported hosts of A. besseyi). Symptoms did not develop during the 4 weeks following inoculation. However, after staining, both eggs and nematodes inside plant tissue of Phalaenopsis roots, strawberry leaf buds, and rice sheath indicated that A. bicaudatus had established in these hosts. These results revealed a potential new host-parasite relationship of A. bicaudatus, and suggest that this nematode may infect these economically important hosts.

Why Do Tropical Mountains Support Exceptionally High Biodiversity? The Eastern Arc Mountains and the Drivers of Saintpaulia Diversity

We combine information about the evolutionary history and distributional patterns of the genus Saintpaulia H. Wendl. (Gesneriaceae; ‘African violets’) to elucidate the factors and processes behind the accumulation of species in tropical montane areas of high biodiversity concentration. We find that high levels of biodiversity in the Eastern Arc Mountains are the result of pre-Quaternary speciation processes and environmental stability. Our results support the hypothesis that climatically stable mountaintops may have acted as climatic refugia for lowland lineages during the Pleistocene by preventing extinctions. In addition, we found evidence for the existence of lowland micro-refugia during the Pleistocene, which may explain the high species diversity of East African coastal forests. We discuss the conservation implications of the results in the context of future climate change.

Enhancing Hispanic Minority Undergraduates’ Botany Laboratory Experiences: Implementation of an Inquiry-Based Plant Tissue Culture Module Exercise

Early involvement of students in hands-on research experiences are known to demystify research and promote the pursuit of careers in science. But in large enrolment departments such opportunities for undergraduates to participate in research are rare. To counteract such lack of opportunities, inquiry-based laboratory module in plant tissue culture was implemented in an undergraduate botany course impacting approximately 140 Hispanic minority students per year. In this module, spread throughout the semester, the students used African violet to gain experience in plant tissue culture techniques. The objective was for the students to learn how to take part of the plant from in vivo to in vitro culture. This required the establishment of aseptic techniques and the use of different media components to multiply plants under in vitro conditions. In depth assessment of gain-of content knowledge and gain-of confidence revealed that our inquiry-based approach allowed the students to learn while increasing their self-perception of scientific methodology. In three semesters, the students reported a 2.5-fold overall increase in the post-module assessment for content knowledge compared to pre-module assessment. Similarly, approximately 85% of the students reported that they gained self-confidence in many aspects pertaining to conducting future research such as the use of primary literature, the design and performance of novel scientific experiments, and the formulation of a testable hypothesis. Though this lab module was solely in plant tissue culture, the inquiry-based nature of the exercise developed students’ research skills and built confidence which is important in increasing retention of students in sciences.

Intraspecific diversity in Sinningia speciosa (Gesneriaceae: Sinningieae), and possible origins of the cultivated florist's gloxinia

The florist's gloxinia is a familiar houseplant in the Gesneriaceae, the botanical family that includes the African violet (Saintpaulia) and other ornamental species. The gloxinia's wild progenitor is Sinningia speciosa (Lodd.) Hiern, a Brazilian endemic. Although it has been cultivated for almost 200 years, little is known about the genetic diversity in S. speciosa, how the wild populations relate to one another or even where the cultivated forms originated. Using available wild collections, preliminary phenetic and phylogenetic investigations were conducted to elucidate the interspecific relationships within S. speciosa and to infer the origins of the cultivars. Amplified fragment length polymorphism (AFLP) analysis was applied to 24 accessions of S. speciosa (17 wild collections, seven cultivars) and one accession each of Sinningia guttata and Sinningia macrophylla. A maximum likelihood (ML) tree was also calculated from an alignment of the nuclear ribosomal internal transcribed spacer sequence from the same 26 accessions. Dice/UPGMA and principal coordinates analysis of the AFLP data partitioned S. speciosa into several distinct clusters, one of which included S. macrophylla. All cultivated 'gloxinias' grouped together in a major cluster with plants from Rio de Janeiro. The AFLP results were compared with a phylogenetic analysis of the ribosomal spacer region, which was informative in S. speciosa. The ML tree generally supported the AFLP results, although several clades lacked strong statistical support. Independent analyses of two different data sets show that S. speciosa is a diverse species comprised of several lineages. Genetic distance estimates calculated from the AFLP data were positively correlated with geographic distances between populations, indicating that reproductive isolation could be driving speciation in this taxon. Molecular markers are under development for population genetic studies in S. speciosa, which will make it possible to define evolutionarily significant units for purposes of conservation.

Climbing Ornamental Plant Used in Indoor Design

Houseplants, also called indoor plants, brighten up your home or office. Indoor gardening is just as fun as having an outdoor garden. In fact, indoor plants not only help clean the environment around them, but they act as a quick decorating tool. The benefits of indoor gardening are numerous. Indoor plants reduce components of indoor air pollution, particularly volatile organic compounds (VOC) such as benzene, toluene, and xylene. The compounds are removed primarily by soil microorganisms. Plants can also remove CO2, which is correlated with lower work performance, from indoor areas (Tarran et al., 2007). The effect has been investigated by NASA for use in spacecrafts (Wolverton, 1988). Plants also appear to reduce airborne microbes and increase humidity. Indoor plants also brighten the room, providing a cheerful sight for those grey and often dreary winter days. And, another big benefit of indoor gardening is there is nothing more relaxing than gardening. Indoor plants are an important part of decor in homes, offices and other buildings. Many plants in your indoor houseplants make for good outdoor garden in the summer too. A large number of plants can be grown indoors as houseplants. There are flowering types or non-flowering types. Good examples of these are Ficus, Palm, Cactus, Saintpaulia, Basil and Parsley which can survive in the more limited light conditions of your home. More than ever ornamental flowers are a part of our life, from simply decorating the house we live in, to beautiful bouquets on our wedding day. We are witnessing today in our country to a considerable increase in consumption of ornamental plants to decorate homes and yards (Cantor, 2008). Some species of climbing flowers are known and used all over the world due to the beauty and ability to decorate. In this paper were presented five species of climbing flowers and the way they can be used in indoor design. These five species are: Dipladenia sanderi, Hoya sp., Jasminum officinale, Passiflora caerulea and Stephanotis floribunda and were obtained from exchanges with United States of America and South Korea. The plants were chosen based on their beautiful shape, flowers, colors and perfume and were studied at the USAMV Cluj-Napoca didactic greenhouse. Based on the observations made on plants will be recommended some ways to use these species in interior design, in order to spread it among consumers

Growth Sensitivity of Corynespora cassiicola to Thiophanate-methyl, Iprodione, and Fludioxonil

An African violet production facility has relied solely on thiophanate-methyl, a site-specific fungicide that possesses a high risk for pathogens to develop resistance, to manage a devastating Corynespora leaf spot problem. During a disease outbreak in September 2007, 325 isolates of C. cassiicola were collected and 40 isolates were randomly selected to determine the pathogen's sensitivity for mycelium growth on agar amended with various concentrations of thiophanate-methyl, iprodione, or fludioxonil. EC50 values, concentration resulting in a 50% reduction in mycelium growth, were determined and indicate a population that currently is sensitive to all three fungicides. Due to the high risk of the pathogen developing resistance to thiophanate-methyl and iprodione, a moderate risk for cross-sensitivity between iprodione and fludioxonil, and phytotoxicity and visual residue problems with protective fungicides such as chlorothalonil, a fungicide rotation is recommended with fludioxonil as the main chemical selection. Accepted for publication 22 July 2011. Published 26 September 2011.

Nuclear DNA content in Sinningia (Gesneriaceae); intraspecific genome size variation and genome characterization in S. speciosa

The Gesneriaceae (Lamiales) is a family of flowering plants comprising >3000 species of mainly tropical origin, the most familiar of which is the cultivated African violet (Saintpaulia spp.). Species of Gesneriaceae are poorly represented in the lists of taxa sampled for genome size estimation; measurements are available for three species of Ramonda and one each of Haberlea, Saintpaulia, and Streptocarpus, all species of Old World origin. We report here nuclear genome size estimates for 10 species of Sinningia, a neotropical genus largely restricted to Brazil. Flow cytometry of leaf cell nuclei showed that holoploid genome size in Sinningia is very small (approximately two times the size of the Arabidopsis genome), and is small compared to the other six species of Gesneriaceae with genome size estimates. We also documented intraspecific genome size variation of 21%-26% within a group of wild Sinningia speciosa (Lodd.) Hiern collections. In addition, we analyzed 1210 genome survey sequences from S. speciosa to characterize basic features of the nuclear genome such as guanine-cytosine content, types of repetitive elements, numbers of protein-coding sequences, and sequences unique to S. speciosa. We included several other angiosperm species as genome size standards, one of which was the snapdragon (Antirrhinum majus L.; Veronicaceae, Lamiales). Multiple measurements on three accessions indicated that the genome size of A. majus is ~633 × 10⁶ base pairs, which is approximately 40% of the previously published estimate.

Inbreeding and inbreeding depression in a threatened endemic plant, the African violet (Saintpaulia ionantha ssp. grotei), of the East Usambara Mountains, Tanzania

AbstractMating among closely‐related individuals in small and isolated plant populations may result in reduced vigour of the inbred offspring, i.e. inbreeding depression, especially in naturally outbreeding plants. Occurrence of inbreeding and inbreeding depression was studied in Saintpaulia ionantha ssp. grotei, a threatened endemic plant species with a narrow ecological amplitude from the East Usambara Mountains. The level of inbreeding (measured as the fixation index, F) was investigated in twelve populations by analyzing variation at one microsatellite marker locus. The effect of one generation of selfing and outcrossing on the progeny fitness was studied by controlled crosses in two small patches that differ in the level isolation. The fixation index (F) across the populations was on the average 0.21 and varied among the populations from substantial inbreeding (F = 0.58) to surplus heterozygosity (F = −0.29). High inbreeding depression (δ) was observed at early and late stages of the life‐cycle. The isolated patch exhibited lower inbreeding depression than did the non‐isolated patch. The results of this study suggest that inbreeding and subsequent inbreeding depression are potential threats to the survival of Saintpaulia populations.

ESTABLISHMENT OF EFFICIENT REGENERATION SYSTEM, ACCLIMATIZATION AND SOMACLONAL VARIATION IN SAINTPAULIA IONANTHA H. WENDL.

Saintpaulia ionantha H. Wendl or commonly known as African violet was successfully established in tissue culture system. Complete plant regeneration was achieved from leaf, petiole, peduncle and floral parts of the plant. MS medium supplemented with 1.0 mg/L IAA and 2.0 mg/L zeatin was found to be the best medium for shoot regeneration in the present work. The plantlets were successfully acclimatized and managed to survive in the green house. The best method for acclimatization of this species was obtained when in vitro plantlets were transferred into planting pots containing mixed soil, which is a mixture of compost, sand and black soil with the ratio of 1:1:2. Some macromorphological studies were carried out in order to compare the in vivo plants and the regenerants. All new plantlets of Saintpaulia ionantha grown in the green house showed the same morphological characters except the height, texture and size of the leaves. In vivo plants height was taller (18.0±0.4 mm) when compared to in vitro plantlets (17.0±0.2 mm). Meanwhile, the leaves of in vivo plants are more hairy on the surface, thicker and the leaves were less green compared to in vitro plantlets. In vivo plants have the same leaves arrangements as in vitro plantlets which was 'rossette' leaves. In vitro plantlets that were transferred to the green house showed very high survival rate (84.0±1.6%).

Cultural Guidelines for Commercial Production of African Violets (Saintpaulia ionantha)

EP1096, a 5-page illustrated fact sheet by J. Chen and R. J. Henny, provides guidelines for the commercial production of African violets including propagation, cultural requirements, and common physiological problems. Published by the UF Department of Environmental Horticulture, February 2009. ENH 1096/EP360: Cultural Guidelines for Commercial Production of African Violets (Saintpaulia ionantha) (ufl.edu)

Brushing Using a Hand Coated with Body Lotion or in a Latex Glove Decreases African Violet Plant Quality and Size

Plants of two cultivars of african violet (Saintpaulia ionantha), ‘Michigan’ and ‘Gisela’, were brushed for 30 or 90 seconds three times per week for 5 weeks with a gloved or nongloved hand to which body lotion had been applied. ‘Michigan’ damage rating and size was more affected by brushing than was ‘Gisela’. Brushing generally increased the damage rating and decreased plant size compared with not brushing. Plants brushed with a gloved hand had lower damage ratings and were larger than those brushed with a nongloved, lotioned hand. Plants brushed for 30 seconds had lower damage ratings and were generally larger than those brushed for 90 seconds. Brushing leaves of african violets, particularly with a hand to which body lotion has been applied, is not recommended because repeated brushing can decrease plant quality and size.

Brushing Using a Hand Coated with Body Lotion or in a Latex Glove Decreases African Violet Plant Quality and Size

Plants of two cultivars of african violet (Saintpaulia ionantha), ‘Michigan’ and ‘Gisela’, were brushed for 30 or 90 seconds three times per week for 5 weeks with a gloved or nongloved hand to which body lotion had been applied. ‘Michigan’ damage rating and size was more affected by brushing than was ‘Gisela’. Brushing generally increased the damage rating and decreased plant size compared with not brushing. Plants brushed with a gloved hand had lower damage ratings and were larger than those brushed with a nongloved, lotioned hand. Plants brushed for 30 seconds had lower damage ratings and were generally larger than those brushed for 90 seconds. Brushing leaves of african violets, particularly with a hand to which body lotion has been applied, is not recommended because repeated brushing can decrease plant quality and size.

Artificial Seed Production from Encapsulated Micro Shoots of Saintpaulia ionantha Wendl. (African Violet)

Artificial seeds were produced from encapsulated micro shoots of Saintpaulia ionantha Wendl. (African violet). The production of artificial seeds of this species gave ideal beads based on firmness, texture, size and shape of beads. The percentage of germination from encapsulated micro shoots influenced by the concentrations of sodium alginate and calcium chloride (CaCl2.2H2O) used. It was found that among the concentrations tested, 3 sodium alginate and the exposure to 1.00 mM CaCl2.2H2O solution for 30 min had produced optimal beads with firm, clear, round and uniform size and suitable for handling. It was also observed that micro shoots obtained from optimization of encapsulation matrix showed the highest percentage of germination (84). Encapsulated micro shoots exposed for 30 min in 100 mM CaCl2.2H2O solution gave the optimal time of hardening process. The findings suggested that the encapsulation method for micro shoots could be used as an alternative to artificial seed derived from somatic embryos of Saintpaulia ionantha. © 2008 Asian Network for Scientific Information.

Identification of hrpL up-regulated genes of Dickeya dadantii

Dickeya dadantii (Erwinia chrysanthemi) is a Gram-negative plant pathogen that invades a wide range of plant species to cause diseases. Hypersensitive response and pathogenicity genes (hrp) are important virulence factors in D. dadantii. However, few hrpL up-regulated genes of D. dadantii have been reported. In this study, a green fluorescence protein (GFP)-based Escherichia coli promoter-probe system was used to identify hrpL up-regulated genes in D. dadantii 3937. From approximate 20,000 library clones screened, hrpA, hrpK, dspE, yijC (a DNA-binding transcriptional regulatory protein) and yecF (unknown function) were identified to be up-regulated by hrpL in D. dadantii 3937. Expression pattern fluorescence of five genes was observed in the wild-type strain and a hrpL deletion mutant strain of D. dadantii 3937 in hrp-inducing minimal medium. Mutants with hrpA, hrpK, dspE, yijC, and yecF genes mutated, respectively, were confirmed, and most of the mutants showed virulence reduction when infecting the plant host African violet (Saintpaulia ionantha).

Studies on Plant Regeneration and Somaclonal Variation in Saintpaulia ionantha Wendl. (African Violet)

Efficient plant regeneration of Saintpaulia ionantha (African violet) has been obtained in the present study. MS medium supplemented with 1.0 mg L(-1) IAA and 2.0 mg L(-1) Zeatin resulted in 100% shoot regeneration and induced the highest number of shoots (average 15.0 +/- 0.8 shoots per explant) after being cultured for 8 weeks. The above hormone combination was optimum for shoot regeneration. Most of Saintpaulia ionantha plantlets derived from tissue culture system could be hardened and transferred to the greenhouse conditions with 84.0 +/- 1.6% success rate. However, regenerated plantlets of Saintpaulia ionantha (even after 12-months-old) failed to flower. Morphological characters of regenerated plantlets of Saintpaulia ionantha were observed and compared with in vivo (intact) plants. Regenerated plantlets showed some differences in morphological characters, such as height and leaf size, texture and colour, but the plantlets showed no variation in leaf arrangement and leaf margin. However, the morphological characters of the regenerated plantlets were found to be unstable.

Plant Regeneration and Floral Bud Formation from Intact Floral Parts of African Violet (Saintpaulia ionantha H. Wendl.) Cultured in vitro

Intact immature flower buds of African violet (Saintpaulia ionantha H. Wendl.) were used as explant sources for in vitro studies. The effect of exogenous hormones, NAA and BAP on the indirect organogenesis of this species was observed. Callus was formed on the cut end (base) of pedicels of floral buds where they were in contact with the medium. When maintained on the same medium, callus was differentiated into adventitious shoots after 10 weeks in culture. MS media supplemented with 2.0 mg L(-1) NAA and 1.0 mg L(-1) BAP gave the highest number of sterile or vegetative floral buds from the surface of callus of the explants, but these buds failed to develop further. The floral buds were expanded as abnormal flowers. The floral structures were smaller in size compared to intact flowers. Petals (corolla) were white to purple in colour but did not form any reproductive organs, i.e., stamens or pistils. All sterile or vegetative floral buds and abnormal flowers survived for 3 months in culture but failed to reach anthesis.

Pollination Observations Of the African Violet In the Taita Hills, Kenya

ABSTRACT The African violet, Saintpaulia teitensis (Gesneriaceae), is an Eastern Arc global biodiversity hotspot endemic. Forest fragments on the Taita Hills in south-eastern Kenya hold the only known wild populations of this plant. The pollination ecology of S. teitensis was investigated through direct observation. S. teitensis flowers show enantiostyly which may promote xenogamy. Pollinators of this endangered plant species were found to be exclusively wild bee species of the genus Amegilla (Apoidea: Aprocrita: Apidae). Four different species of Amegilla were recorded visiting S. teitensis. Observations of bee floral visitors showed distinctive floral manipulation (buzz pollination) for release of pollen by pollinating bees. Amegilla spp. visiting S. teitensis were observed to feed from other forest-floor plant species (Acanthaceae and Lamiaceae) and on crops in adjacent small-scale mixed agriculture farms. Future conservation and management of this endangered plant needs to take into account the needs ...