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Poor growth and nuclear abnormalities observable in some space-grown plants have been hypothesized as due to a combination of factors such as degree of development, the specific way the plants are grown and the way they experience multiple stresses, some of which are space-specific. Data from a 132-day experiment on 'Mir' using embryogenic cell cultures of daylily (Hemerocallis) allow seemingly contradictory evidence from earlier Shuttle missions to be harmonized: a) the more developed an embryo the less likely it is to suffer catastrophic cell stress during growth, whereas the less developed it is, the greater its vulnerability; (b) the extent to which the stress becomes manifest is also dependent on the extent of pre-existing stresses imposed by suboptimal growing conditions; (c) an appropriate, albeit undesirable, 'stress match' with other non-equilibrium determinants, much like a 'tug of war', can result in genomic variations in space. It is not understood what is/are the feature(s) of the space environment that cause the various cell division perturbations but they have not yet been mimicked on earth. The stress symptoms were found only in space materials and, as predicted, they were most frequently encountered in smaller, less-developed materials grown under non-optimized conditions. It is concluded that, while any substantial deviation from 'optimum' can be a 'stress', spaceflight subjects vulnerable materials to cell division or DNA-repair stress(es) that appear distinctive, but remain elusive so far. Fastidiously-controlled growing environments must be devised to resolve the matter of direct versus indirect effects of space. On a practical level, it is predicted that adapting plant biotechnologies to space conditions will not be a casual matter. Grant Numbers: NAG21026.

The analysis and stability of carotenoids in the flowers of daylily (Hemerocallis disticha) as affected by soaking and drying treatments were studied. The various carotenoids in the flowers of daylily were analyzed using a reversed-phase C(30) HPLC column and a mobile phase of methanol/methylene chloride/2-propanol (89:1:10, v/v/v) with methanol/methylene chloride (45:55, v/v) as sample solvent. Twenty-one pigments were resolved, of which 14 carotenoids were identified, including neoxanthin, violaxanthin, violeoxanthin, lutein-5,6-epoxide, lutein, zeaxanthin, beta-cryptoxanthin, all-trans-beta-carotene, and their cis isomers, based on spectral characteristics and Q ratios. Prior to hot-air-drying (50 degrees C) or freeze-drying, some of the daylily flowers were subjected to soaking in a sodium sulfite solution (1%) for 4 h. Under either the hot-air- or the freeze-drying treatment, the amounts of most carotenoids were higher in the soaked daylily flowers than in those that were not soaked. With hot-air-drying, the amount of cis carotenoids showed a higher yield in soaked samples than in nonsoaked samples. However, with freeze-drying, only a minor change of each carotenoid was observed for both soaked and nonsoaked samples. Also, air-drying resulted in a higher loss of carotenoids than freeze-drying.

Nine herbicides registered for use on turf and ornamentals were applied semiannually for 2 years to 9 species of field grown herbaceous flowering perennials. The herbicides used were Balan (benefin), Betasan (bensulide), Dacthal (DCPA), Devrinol (napropamide), Fusilade (fluazifop), Ornamental Herbicide 2 (oxyfluorfen + pendimethalin), Pennant (metolachlor), Poast (sethoxydim), and Ronstar (oxadiazon). The perennials included fernleaf yarrow, shasta daisy, coreopsis, dianthus, daylily, candytuft, red hot poker, statice, and phlox. Betasan produced no visual phytotoxicity. All other treatments, excluding Ornamental Herbicide 2 (OH-2), caused less than 20% injury to all species tested. OH-2 caused 40%, 39%, and 30% injury to daylily, yarrow, and red hot poker, respectively. Economically tolerable (less than 25%) injury was exhibited by phlox and shasta daisy treated with OH-2, by daylily treated with Pennant, and by phlox treated with Ronstar. OH-2 increased flowering of coreopsis and statice by 97% and 235%, respectively, while it reduced plant area of phlox by 53% and flowering of phlox by 34%. Both Pennant and OH-2 reduced flowering of dianthus by nearly 30%.

The occurrence in Japan of the daylily thrips, Frankliniella hemerocallis, is confirmed. This thrips probably originated in Asia or Eurasia, because it is highly specific to Hemerocallis [Liliaceae] which is native to these areas. This thrips feeds on leaf, stem and petals rather than pollen. The second instar larva is described, and a key provided to the adults of Frankliniella species recorded from Japan.

During senescence, petals of attached daylily (Hemerocallis hybrid cv Cradle Song) flowers lost 95% sugar and 65% dry weight over the first 24 h, with 30% of dry weight loss coming from nonsugar components. Detaching flowers did not delay senescence, but halted loss of carbohydrate and amino acid, suggesting that loss in the intact state was due to phloem export. Petal autolysis occurred mainly in the interveinal parenchyma, causing vascular strands to begin separating from the petal mass. Such vascular strands still stained with tetrazolium and accumulated sucrose, indicating a retained viability. Their sucrose accumulation rates were high in comparison with those of other plant tissues, and the accumulated product was mainly sucrose. Sucrose synthesis took place in the senescent petal, and sucrose was the principal sugar in phloem exudate, whereas hydroxyproline and glutamine were the main transport amino acids. [14C]Sucrose applied to attached senescent flowers was rapidly translocated to other parts of the plant, particularly developing flower buds. Thus, onset of phloem export allowed most of the soluble carbohydrate and amino acid in the senescing flower to be retrieved by the plant. Additional salvaged material came from proteins and possibly from structural carbohydrate. Over a 12-h period, the flower switched from acting as a strong carbohydrate sink during expansion to become a strong source during senescence. This rapid reversal offers potential for phloem transport studies.

The flowers of daylily (Hemerocallis x hybrida cv. Cradle Song) open at midnight, start to senesce 12 h later, and are completely senescent by the following midnight. Differential screening of a cDNA library constructed from tepals of flowers showing incipient senescence revealed 25 clones that were strongly up-regulated in senescent tepals. Re-screening and interactive Southern analysis of these clones revealed 3 families of up-regulated clones. Transcripts of one clone, SEN10, were not detectable at midnight, but increased dramatically as senescence proceeded. The derived amino acid sequence of the full-length cDNA (SEN102) has strong homology with cysteine proteases that have been reported from other plant tissues. The sequence contains a secretory signal peptide and a probable prosequence upstream of the mature protein. Amino acids critical to the active site and structure of cysteine proteases are conserved, and the C-terminus of the polypeptide has a unique putative endoplasmic reticulum retention signal -RDEL.

Mesophyll protoplasts were isolated from leaf tissues of a diploid daylily (Hemerocallisx'Red Magic') by enzymatic digestion with a solution containing 0.5% Pectolyase Y-23, 0.1% Cellulase R-10, 0.1% Driselase, 0.6 M sorbitol and half-strength MS inorganic salts. When cultured on MS medium supplemented with 0.5 mg/l NAA and 0.5 mg/l BA, the protoplasts underwent sustained division to produce multicellular colonies. The optimal plating density for cell division was 0.5 × 10(5) protoplasts/ml. The highest plating efficiency was obtained in cultures grown in media solidified with 0.2% Gelrite. Under these conditions, formation of colonies occurred from 14% of cultured protoplasts. Calli were recovered from 9 colonies only after the cultures were treated with a conditioned medium. Intact plants were regenerated from protoplast-derived calli through organogenesis.

Daylilies (Hemerocallis species and cultivars) are herbaceous perennials much sought after for their showy albeit very short-lived blooms. The mature plant is comprised of fans (ramets) consisting of an underground stem (rhizome), an expansive fibrous or fibrous-tuberous root system, and strap-shaped leaves. Axillary buds can be forced to yield vegetative separations. The deciduous or evergreen foliage consists of sheathed-at-the-base, heavily ribbed leaves which when mature (Fitter and Krikorian 1985; Smith et al. 1989) are long and two- ranked. Flowers are borne on a scape, often branched and largely leafless but with bracts, and shoot propagules (“proliferations”). Flower buds per scape may vary from around 5 to 20 (Wilkins 1985).

Daylilies (Hemerocallis species and cultivars) are herbaceous perennials much sought after for their showy, albeit very short-lived, blooms. The genus has traditionally been classified in the family Liliaceae but now is placed in the Hemerocallidaceae comprising a single genus and some 14 or 15 species (Dahlgren et al. 1985). The family is endemic to the temperate regions of Asia, but ranges from eastern and southern Europe to northern, eastern, and central China, to Korea and Japan. Hemerocallis assumes the gross habit of other clump-forming perennial monocotyledons. The mature plant is composed of fans (ramets) which consist of an underground stem (rhizome), roots, leaves, and a flowering scape. The crown of the plant, referred to horticulturally as the vegetative stem or rootstock, sometimes and erroneously called a pseudobulb, produces long, strap-shaped leaves above andfibrous roots below. Axillary buds may grow or remain dormant and can be forced to yield vegetative separations. The crown is said to be slowly pulled into the ground with continued contractile root growth (Wilkins 1985). An expansive fibrous or fibrous-tuberous root system anchors the plant. The foliage, which may be deciduous or evergreen, consists of sheathed-at-the-base, heavily ribbed leaves which when mature (Fitter and Krikorian 1985; Smith et al. 1989) are long and two-ranked (distichous). Flowers are borne on afloral stalk or scape which is often branched and largely leafless but with some leaf-like bracts, and shoot propagules called proliferations. The number of flower buds per scape may vary (approx. 5 to 12). Flowers are hypogynous, trimerous (3+3 petaloid) and basally connate into a tube; tepals may be apically recurved. Theflowers are perfect and fairly large and last only 1 day (Bielski and Reid 1992). The plants are genetically heterozygous and hence seedlings must be raised to maturity before their qualities are assessable. This generally takes 3-4 years for varieties that are “fast” and longer for those that are “slow”. When a plant with a desirable phenotype is obtained, it is invariably multiplied vegetatively so as to fix the genotype.

The daylily (Hemerocallis fulva) and nightlily (H. citrina) are typical examples of a butterfly-pollination system and a hawkmoth-pollination system, respectively. H. fulva has diurnal, reddish or orange-colored flowers and is mainly pollinated by diurnal swallowtail butterflies. H. citrina has nocturnal, yellowish flowers with a sweet fragrance and is pollinated by nocturnal hawkmoths. We evaluated the relative roles of flower color and scent on the evolutionary shift from a diurnally flowering ancestor to H. citrina. We conducted a series of experiments that mimic situations in which mutants differing in either flower color, floral scent or both appeared in a diurnally flowering population. An experimental array of 6 × 6 potted plants, mixed with 24 plants of H. fulva and 12 plants of either F1 or F2 hybrids, were placed in the field, and visitations of swallowtail butterflies and nocturnal hawkmoths were recorded with camcorders. Swallowtail butterflies preferentially visited reddish or orange-colored flowers and hawkmoths preferentially visited yellowish flowers. Neither swallowtail butterflies nor nocturnal hawkmoths showed significant preferences for overall scent emission. Our results suggest that mutations in flower color would be more relevant to the adaptive shift from a diurnally flowering ancestor to H. citrina than that in floral scent.

Dry weight, water content, soluble carbohydrate content, and carbohydrate composition of daylily (Hemerocallis hybrid cv Cradle Song) flower petals were monitored in the 3 d leading up to full opening and in the first day of senescence. Timing of events was related to the time (hour 0) when flower expansion was 60% complete. Petal dry weight increased linearly from hour -62 (tight bud) to hour 10 (fully developed flower), then fell rapidly to hour 34 as senescence advanced. Increase in water content was proportional to dry weight increase from hour -62 to hour -14, but was more rapid as the bud cracked and the flower opened, giving an increase in fresh weight/dry weight ratio. Soluble carbohydrate was 50% of petal dry weight up to hour 10, then decreased during senescence to reach 4% by hour 34. Up until hour -14, fructan accounted for 80% of the soluble carbohydrate in the petals, whereas hexose accounted for only 2%. Fructan hydrolysis started just prior to bud crack at hour -14, reaching completion by hour 10 when no detectable fructan remained, and fructose plus glucose accounted for more than 80% of the total soluble carbohydrate. The proportion of sucrose remained constant throughout development. Osmolality of petal cell sap increased significantly during fructan hydrolysis, from 0.300 to 0.340 osmolal. Cycloheximide applied to excised buds between hour -38 and hour -14 halted both fructan hydrolysis and flower expansion. The findings suggest that onset of fructan hydrolysis, with the concomitant large increase in osmoticum, is an important event driving flower expansion in daylily.

Callus cultures of the diploid daylily (Hemerocallis) clone Autumn Blaze' were initiated and maintained in hormone-containing nutrient medium. At various times (from 6 weeks to 1 year) after being initiated, hormone-derived cultures were evaluated for their ability to be maintained and to multiply on hormone-free medium at low pH (between pH 4 and 4.5). Cultures had to be exposed to hormone-containing medium for at least 12 weeks before they could be maintained on hormone-free medium at low pH. The transition to maintainability on low pH hormone-free medium included the production of many aberrant embryonal forms ( neomorphs'). However, all hormone-derived cultures tested consisted entirely of preglobular stage proembryos (PGSPs) after 12-24 weeks on low pH hormone-free medium. PGSP cultures have been maintained and multiplied as such for over 1 year on low pH hormone-free medium. PGSPs continue their development into various somatic embryo stages when cultured on hormone-free medium buffered at pH 5.8. The production of well-formed somatic embryos was greatly enhanced when PGSPs were plated on activated charcoal impregnated filter papers that were placed on top of the agar surface. The gross morphology and histology of the PGSPs and stages of somatic embryo development are presented. The work shows that the ability of hormone-free medium at low pH to permit PGSP multiplication without development into later stages of embryo development is not restricted to carrot.

Em Santa Catarina, Brasil, destaca-se a produção de hemerocale, planta herbácea, perene e muito utilizada no paisagismo. Existem diversas cultivares desta espécie, dentre as quais, destaca-se Graziela Barroso, lançada no mercado em 2003. Embora se tenha conhecimento a respeito das novas cultivares de Hemerocallis spp., pouco se sabe sobre suas variáveis de crescimento, quando submetidas a aplicações de reguladores vegetais. Desta forma, o objetivo do presente trabalho foi estudar as variáveis de crescimento (TCC – Taxa de Crescimento da Cultura; TCR – Taxa de Crescimento Relativo da Cultura; RAF – Razão de Área Foliar e AFE – Área Foliar Específica) em Hemerocallis hybrida cv. Graziela Barroso, submetida à aplicação de diferentes concentrações de GA3 (0 mg L-1 (somente água); 15 mg L-1 e 30 mg L-1) no verão, outono e inverno do ano de 2005, em Joinville, SC. As pulverizações foram semanais, iniciadas uma semana após o plantio, totalizando 10 aplicações por tratamento. Semanalmente foram retiradas 3 plantas/tratamento para análises das variáveis. Foram utilizadas 300 mudas por estação, plantadas em vasos de polietileno (2,8 litros), preenchidos com substrato NPK 10:10:10; esterco de ave; solo e casca de arroz carbonizada, na proporção 1:8:80:100. As mudas foram cultivadas em estufa com irrigação manual. Foi utilizado o delineamento experimental inteiramente casualizado com fatorial 3x10, três concentrações, e dez aplicações de GA3. Nas três estações estudadas não houve resposta significativa das variáveis de crescimento aos tratamentos com GA3, não sendo recomendada a aplicação de GA3 com o intuito de incrementar o crescimento de Hemerocallis hybrida cv. Graziela Barroso.

Infection process of Puccinia hemerocallidis, the causal agent of daylily rust, and resistance responses in eight daylily cultivars, were studied macroscopically and microscopically. After germination of urediniospores, appressoria were formed at the tip of germ tubes and penetrated through stomatal openings. Intercellular hyphae aggregated and formed uredia under the infection sites, and released urediniospores after rupturing the epidermis. In highly resistant cultivars `Prairie Blue Eyes' and `Bertie Ferris', intercellular hyphal growth was restricted and uredia were not formed. No macroscopic symptoms of the disease were present on the leaf surface, although a few collapsed cells were observed microscopically. Both resistant and moderately resistant reactions were characterized by necrotic lesions with many collapsed cells under infection sites. The difference between these two reactions was that uredia and urediniospores were observed on the moderately resistant cultivar `Chicago Apache', but not on resistant cultivars, `Buttered Popcorn' and `Stella De Oro'. Sporulation was observed on both moderately susceptible and susceptible cultivars, but latent periods were delayed and the amount of urediniospore production was reduced on moderately susceptible cultivars, `Mary Todd' and `Chorus Line', compared to the susceptible cultivar `Pardon Me'. The results indicate that the hypersensitive cell death is one of the resistance responses to daylily rust, but necrotic lesions on leaf surfaces are associated with the amount of collapsed host cells. The delayed latent periods and reduced sporulation that resulted from restricted intercellular hyphal growth could represent another resistance mechanism in the daylily rust pathosystem.

Two tetraploid and two diploid varieties of daylily were micropropagated on a shaker in MS liquid medium containing high and low sugar levels (3% and 6% sucrose), 2 BA levels (0.32 and 3.2 μm), at two densities (57 and 171 explants/L), in the presence (0.32 μm) and absence of ancymidol. Biomass and media use were partitioned for the four genotypes and 32 cultural conditions with three replications (4 × 2 × 2 × 2 × 2 × 3). Genotype greatly effected f resh weight, dry weight, media, sugar and water use, but ploidy had little effect. Vessels at high density (171 explants/L) produced 1.8× more fresh weight, 1.4× more dry weight, used 1.6× more media and sugar than low density (57 explants/L). Plants from low density were 1.7× larger, 2× greater dry weight, and used 2× more sugar and media, than from high-density culture (per explant). Doubling the initial sugar level increased dry weight and sugar use 1.3×. There was a linear relation between sugar residual and percentage of dry weight (R2 = 0.55, P < 0.0001), where a 1% increase in °Brix raised percentage of dry weight 1.8 units over the range of 9% to 22%. Ancymidol and BA had less effect on plant size, sugar and media use than genotype or plant density. Greenhouse survival was reduced by including ancymidol (90% to 30%) and increased BA concentration (85% to 35%). Lab plant density and initial sugar concentration had no apparent effect on greenhouse growth. `Barbara Mitchell' had greatest mass, used more sugar and media than the other varieties, yet had least greenhouse growth. Nutrient use with `Barbara Mitchell' was linearly correlated (R2>80%) to lab growth for seven of 12 ions. P and Fe supply was inadequate to support optimal growth, as indicated by low residual in media (>1% of MS formulation).

Daylily (Hemerocallis sp.) plants declined in a homeowner's backyard in Walhalla, SC in June 2004. The backyard in northwestern South Carolina contained multiple, hardwood tree stumps, was surrounded by mature hardwood trees, and contained a dogwood tree showing symptoms of Armillaria root rot. Daylily plants were stunted and necrosis of leaves began at the leaf tips. A cross section through the crown of the wilting plants revealed necrotic areas with the presence of white mycelial fans. Rhizomorphs were found in the direct vicinity of the daylily root system, on the roots of the dogwood, and throughout surrounding soil. Diseased daylily crowns, rhizomorphs, and dogwood bark containing mycelial fans were collected. Small sections of white mycelial fans from daylily crowns and the dogwood sample were transferred to benomyl dichloran streptomycin (BDS) selective medium. Rhizomorph pieces were surface sterilized in a 0.6% sodium hypochlorite solution for 10 min and rinsed with sterile water before being transferred to BDS selective medium. Fungal cultures from all three sources looked similar on BDS medium and developed mainly crustose mycelium with some parts being aerial. After 1 week of incubation at room temperature in the dark, all cultures developed nonmelanized, mycelial fans that initiated from the center of the colony. The nucleotide sequences of internal transcribed spacer regions 1 and 2 and the intergenic spacer region 1 were identical for all isolates, and a BLAST search in GenBank of these sequences confirmed the identity of the pathogen as A. gallica (Marxmueller & Romagnesi) for both loci. To our knowledge, this is the first report of A. gallica causing disease on Hemerocallis spp. Our findings indicate that daylilies might be at risk for infection and should not be cultivated in soils containing rhizomorphs from pathogenic Armillaria species.

To improve somatic embryogenesis of Daylilies (Hemerocallis hybrid); six types of explants namely immature seeds, immature embryos, mature embryos, young inflorescence, ovary-sections and filaments of daylily flower buds were investigated as source of explants. Explants from field grown plants were surface sterilized and followed by culturing on MS medium supplemented with 1.5 mg/L NAA and 0.5 mg/L BAP for four weeks. Explants were scored for development of embryogenic tissue and formation of somatic embryos with/without the formation of an intermediate callus stage. Both mature and immature embryo explants produced direct development of embryogenic tissue followed by somatic embryos. Young inflorescence explants developed compact calli and produced roots around cut ends and showed no somatic embryogenesis. Ovary explants exhibited swelling and not produced embryogenesis. Production of embryogenic callus and formation of somatic embryos in filament explants depended on the sizes of flower buds. Explants from 0.5 to 1.2 mm size flower buds produced calli and formed somatic embryos while explants from sizes over 1.2 mm flower buds only non-embryogenic calli. Immature seeds failed to grow. The results indicated that immature and mature embryos and filaments from young flower buds responded better than other explants for developing somatic embryos in daylily.

During Fall 2003, a study similar to that of Fall 2002 was conducted to determine the effect of crown manipulation on shoot production in four cultivars of daylily. Three crown manipulation treatments: (1) the shoot cut back two centimeters from crown, (2) the shoot cut back to the crown, and (3) shoot cut back to the crown and scooped out were compared to a control. Four daylily cultivars, `Bull Durham', `Amber Lamp', `Angus McLeod', and `Alvatine Taylor' were used in this study. After eight weeks of observations, the results showed that the cut back to crown treatment caused a significant increase in the number of shoots when compared to the control and other two treatments. Shoot production for the cultivar `Angus McLeod' was significantly better than the other cultivars. Results obtained for Fall 2003 study were similar to that of Fall 2002. These results imply that cutting the shoots back to the crown in some daylily cultivars could possibly be used to enhance multiplication of daylilies during propagation.

In August 2000, rust symptoms were observed on the leaves of daylily plants (Hemerocallis sp. cv. Pardon Me) at a nursery in Dearing, GA. Based on urediniospore characters, the pathogen was tentatively identified as Puccinia hemerocallidis Thuem. Urediniospores were globose to ellipsoid and measured 19 to 30 × 17 to 22 μm (average size of 22 × 19 μm), corresponding to the previously reported description from Japan (1). Teliospores were absent from the sample but were found on daylily plants (cv. Star Struck) with symptoms similar to cv. Pardon Me from the same nursery in Dearing beginning in October 2000. However, the teliospores differed from those in the published description in that many one-celled teliospores (i.e., mesospores), measuring 32 to 43 × 14 to 19 μm (average size of 38 × 16 μm), were produced in addition to two-celled teliospores, which measured 41 to 53 × 16 to 21 μm (average size of 46 × 18 μm). Similar mesospores were present in a slide from an isotype specimen of P. hemerocallidis (US 72719) housed in the U.S. National Fungus Collection (Beltsville, MD). Daylily plants (cv. Pardon Me) were reinoculated with urediniospores by shaking infected plants over uninfected plants and exposing plants to 100% relative humidity for 24 h. Initial symptoms of small, discrete, yellow spots and streaks on the upper surfaces of leaves developed within 3 to 7 days, and uredia with urediniospores were evident at 7 to 14 days after inoculation. Daylily rust is native to Asia and may have been introduced into Georgia on plant materials sent from Central America. The original source of daylily rust is unclear because Central American producers also purchase and import plants from the United States for propagation and then sell divisions back to U.S. growers. Daylily rust is a disease of major concern for both daylily producers and gardeners. References: (1) N. Hiratsuka, et al. The Rust Flora of Japan. Tsukuba Shuppankai, Ibaraki, Japan, 1992.

The albino genetic characteristic is a lethal condition in the post-seedling stage in plants. Although, it is an undesirable genetic characteristic, it is however an interesting genetic condition that can be utilized as a good practical genetic exercise for plant genetic and breeding courses. In this study, four commercial hybrid varieties of Hemerocallis were crossed as followed: A) “Stella D'ora” (with light orange flower) × “Happy Return” (with yellow flower); B) “Dark-eyed Magic” (purple with pink/cream variegated flower) × “Stella D'ora” (yellow flower). The seeds from these crosses were harvested and germinated in a plastic flat containing metromix 500 soil medium and placed under greenhouse condition. The germination of the seeds from each of the crosses resulted in the expression of green and albino seedlings in the F2; showing the typical Mendelian segregation of a dihybrid cross. Green was found to be dominant to albino. All the albino seedlings withered and died 2 weeks after germination. All four commercial hybrid varieties are carrier of the albino recessive gene.

A plant regeneration protocol has been successfully developed to mass propagate daylilies. Experiments were conducted to determine source (BA, KN, and ZT) and concentration (0, 1.0, 2.0, and 3.0 mg/L) of cytokinins and sugars (glucose, surcose, and maltose) to be used in the medium. Studies were also conducted to determine the influence of flower bud size (5, 10, 15, and 20 mm) as explant source. Based on results from these studies a protocol for propagating daylilies was developed. The procedure involved using filament explants from daylily flower buds ranging in sizes from 5 to 10 mm. The filaments when cultured on MS+BAP (3.0 mg/L)+ IAA (0.5 mg/L) medium,formed globular somatic embryos in 4 weeks. Complete plants were regenerated within a period of 6 to 7 months. Upon acclimatization, 100% of the tissue culture generated raised plants survived under greenhouse conditions.

Horticulturalists manipulate phloem transport to achieve horticulturally-desirable results. The resulting crop behaviour can help show how phloem works. In apple, the use of dwarfing rootstocks and pruning management has greatly increased fruit sink capacity at the expense of root and shoot sinks. Annual fruit yield can exceed100 t ha –1 and account for 65% of total photosynthate. If photosynthetic capacity exceeds fruit sink capacity, there can be either a feedback reduction in photosynthesis, or accumulation of phloem sugars in the fruit apoplast. In sugarcane, the sink is a linear body encasing the full length of the phloem strands from leaf to root. Lateral unloading must occur along the full length of the phloem. Unloading or loading may occur in the same segment of phloem depending on conditions. In the ornamental lily and daylily, the developing flower bud is a powerful sink, doubling in dry weight each 48 h in the week of development from small bud to opening. Once the flower is open, the phloem changes rapidly from unloading behaviour as the tepals become vigorous exporters. The change in behaviour may be coupled with processes mediating senescence and cell death. Implications to phloem function are discussed.

In the United States, the common daylily is cultivated as an ornamental. However, in other countries, such as China and Japan, it is an important food crop. With this in mind, a study was conducted to determine the mineral nutrient content of edible parts (flower buds, flowers and tubers) of the daylily plant. Edible parts were analyzed for P, K, Ca, Mg, Mn, Fe, B, Cu, Al, and Na. Results of this study showed that flower buds had significantly higher level of P and Mg than tubers and flowers. The K and B concentration in flower buds were similar to flowers, but significantly greater than in the tubers. The respective Zn concentrations in flowers and flower buds were 32% and 23% greater than those in the tubers. There was no difference in the Mn concentration among the edible parts. Tuber contained significantly higher contents of Ca and Cu than the flowers and flower buds. It also had 10.6-, 14.3-, and 2.8-times greater concentration of Mn, Al, and Na, respectively, than the combined average flower buds and flowers. From this study, daylily appears to have potential as a nutritious food source for human consumption.

As in many commercially important flowers, especially the monocotyledonous geophytes, senescence of the ephemeral daylily flower (Hemerocallis) does not involve ethylene. By differentially screening a cDNA library constructed from mRNA extracted from daylily petals in the earliest stages of senescence, clones were isolated whose transcription is up-regulated coordinately with the onset of senescence. One of these clones, sen12, was found to be a transcription factor. The deduced amino acid sequence of sen12 contains a MADS-box and an associated K-box similar to transcription factors suggested to control floral morphogenesis in a variety of different species. Northern blot hybridization showed sen12 to be highly upregulated before and during visible flower senescence. The expression of homologous genes during senescence of other flowers will be reported.

Hemerocallis and Musa clones grown under aseptic conditions provide valuable test systems wherein both morphological and biochemical prerequisites for expression of morphological competence from protoplasts can be investigated. While there is considerable opportunity to study protoplast isolation and regeneration per se, the greatest challenge will be to induce, controllably, useful change(s) by co-use of molecular biology and protoplast culture-related methodologies. But the very way in which daylilies and bananas/plantains grow as plants imposes at present certain limitations on achieving cultures which can express their presumed, innate totipotency. Nevertheless, progress has been made and will continue, provided realistic strategies are adopted. When this is fully achieved, the true genetic engineering and use of protoplasts for Hemerocallis and Musa improvement can be realized.

Hemerocallis plantlets maintained in vitro for extended periods of time in tightly closed culture vessels frequently show a phenotype, albeit on a miniaturized scale, typical of more mature, field-grown plants. The positive relationship of elevated ethylene in the headspace of such vessels to the phase shift from juvenile to mature form is established. Rigorous restriction in air exchange with the external environment by means of silicone grease seals hastens the phase change and improves uniformity of response. Although some plantlets may take longer to accumulate enough ethylene in sealed jars to undergo change, added ethylene and ethylene-releasing agents promote it. Ethylene adsorbants (e.g. mercuric perchlorate) block the shift of juvenile to mature form. Critical ambient ethylene level for the shift is ca 1 microliter l-1. Levels up to 1000 microliters l-1 do not hasten the response but are not toxic. The phase change is fully reversible when air exchange permits ethylene to drop below 1 microliter l-1. At least 1 microliter l-1 ethylene is required to sustain the mature phenotype. The ethylene synthesis inhibitor aminoethoxyvinylglycine (AVG) prevents the phase change, while the ethylene biosynthesis intermediate 1-aminocyclopropanecarboxylic acid (ACC) improves it. KOH, as a CO2 absorbent, does not prevent the phase change. Histology sections demonstrate subtle changes in the form of shoot tips of plantlets undergoing phase change.

Daylily plantlets with tetraploid or octaploid chromosome numbers were induced from colchicine-treated diploid callus (2n=22). Callus tissue of the daylily Hemerocallis flava L. was placed on a morphogenetic induction medium, a modified MS formula supplemented with 1 mg 2,4-D and 1 mg kinetin/liter, plus 0,10, 20, or 40 mg/liter colchicine in the dark at 12°C for 3 days and recuperated for 1 week under the same environmental conditions except that colchicine was left out. The calluses were then returned to the normal growth temperature 25°C. Ploidy was identified by chromosome counts of squashed root-tip cells collected from the newly potted plantlets and later by measurements of stomates and pollen grains. Over 50% of the plants initiated from the colchicine-treated calluses were completely tetraploid. All of the plantlets differentiated from untreated callus had a diploid number of 22. Of the 3 colchicine levels applied, the 20 mg/liter treatment appeared to be the most effective in production of tetraploidy.

Tetraploids of daylily have taken a leading position among the daylily cultivars due to desirable traits such as vigorous growth and flowers with more intense colour. In our previous studies, several tetraploids of daylily cultivars ‘Blink of an Eye’ and ‘Berlin Multi’ were obtained using in vitro techniques with different antimitotic agents (colchicine, oryzalin, trifluralin, and amiprophos methyl). The purposes of this study were to evaluate changes in daylily tetraploids in relation to their diploid counterparts and to assess variation among diploids and tetraploids derived from genetically homogenous plant material treated with antimitotic agents. In the first year of the ex vitro cultivation, growth of tetraploids was poorer in comparison with diploids, but in the second year, tetraploid growth was much more vigorous. Compared to diploids, in tetraploids of both cultivars percentage of flowering plants was lower, flowering was delayed by 8 days and 1 month in ‘Blink of an Eye’ and ‘Berlin Multi’, respectively, and bud number per scape was lower by approximately 20 and 40 %, respectively. Tetraploid leaves and flowers of both cultivars were significantly larger, chlorophyll concentration index was higher by approximately 40 %, and stomata were longer by 35 %. In ‘Berlin Multi’ tetraploids, inflorescence stems were shorter by 20 %. In ‘Blink of an Eye’, variation in flower colour tone and shape and stamen malformation rate was detected both within the unconverted diploids and tetraploids but was more evident in tetraploids. In both cultivars, variation was also found in the nuclear DNA content, which ranged in diploids and tetraploids, respectively, 8.02–8.53 and 16.01–17.13 pg in ‘Berlin Multi’ and 8.28–8.71 and 15.93–17.36 pg in ‘Blink of an Eye’. Since the variation, while less evident, also occurred in the diploids (regenerated from the antimitotic treated material), we suppose that these variations could be due to antimitotic agents that can induce not only chromosome doubling but also chromosomal and gene mutations. The extent and character of these changes can be related to parental genotype and/or antimitotic agent. Further research is required at the cytological and molecular level to explain the character of changes, epigenetic and/or genetic.

Thirteen preemergence herbicides were evaluated for phytotoxicity to container grown hosta (Hosta spp. Tratt. ‘Hyacinthina’) and daylily (Hemerocallis spp. L. ‘Sammy Russell’). Severe injury (28 to 55%) was observed from Ronstar (oxadiazon) and Goal (oxyfluorfen) for both species. The other herbicides did not cause visual injury. Three herbicides, Surflan (oryzalin), Endurance (prodiamine) and Pennant (metolachlor), were selected to investigate plant tolerance in field plantings at 1.1, 2.2, and 4.5 kg/ha (1, 2, and 4 lb/A). None of these herbicides caused visual injury or reduced shoot or root weight for 60 or 90 days after treatment. Daylily flower number was not affected by any of the herbicide treatments.

Daylily plantlets generated on semi-solid media from morphogenetically competent cells or morphogenetically competent cells regenerated from protoplasts can give rise in aseptic culture to plantlets with a mature phenotype. The individual leaves of these plantlets open to the extreme base so that no encircling leaf sheath is present. This permits the overlapping bases and leaves to assume an open fan-like arrangement. The occurrence of fans correlates with exceptionally tightly sealed culture vessels and experiments to date suggest a gaseous component is associated with this change of growth form. It has not been possible to fix the mature growth mode, however, and new leaf growth assumes the more normal juvenile phenotype when the gaseous environment is altered by admitting or exposure to room air.

We have developed methods for the isolation of condensed mitotic and meiotic chromosomes from plant protoplasts. The chromosomes can be isolated from a variety of tissues: meiocytes, root tips, cell cultures, and from a variety of species: tobacco, tomato, lily, daylily, onion, and peas. The limiting steps are the ability to obtain synchronously dividing cells and conversion of those cells into protoplasts. We have also been able to demonstrate uptake of isolated chromosomes by recipient protoplasts with fluorescence microscopy at a frequency of 1%. We could partially fractionate chromosomes by size, but we also, unfortunately, were able to show that the in vitro size did not correspond well to the relative in vivo size, so the fractionation method was not noticeably useful. We have not obtained an actual genetic transformation as yet.

Background Daylily flowers, the flower and bud parts of Hemerocallis citrina or H. fulva, are well known as Wang-You-Cao in Chinese, meaning forget-one’s sadness plant. However, the major types of active constituents responsible for the neurological effects remain unclear. This study was to examine the protective effects of hydroalcoholic extract and fractions and to identify the active fractions. Methods The extract of daylily flowers was separated with AB-8 resin into different fractions containing non-phenolic compounds, phenolic acid derivatives and flavonoids as determined using UPLC-DAD chromatograms. The neuroprotective activity was measured by evaluating the cell viability and lactate dehydrogenase release using PC12 cell damage models induced by corticosterone and glutamate. The neurological mechanisms were explored by determining their effect on the levels of dopamine (DA), 5-hydroxy tryptamine (5-HT), γ-aminobutyric acid (GABA), noradrenaline (NE) and acetylcholine (ACh) in the cell culture medium measured using an LC-MS/MS method. Results Pretreatment of PC12 cells with the extract and phenolic fractions of daylily flowers at concentrations ranging from 0.63 to 5 mg raw material/mL significantly reversed corticosterone- and glutamate-induced neurotoxicity in a dose-dependent manner. The fractions containing phenolic acid derivatives (0.59% w/w in the flowers) and/or flavonoids (0.60% w/w) exerted similar dose-dependent neuroprotective effect whereas the fractions with non-phenolic compounds exhibited no activity. The presence of phenolic acid derivatives in the corticosterone- and glutamate-treated PC12 cells elevated the DA level in the cell culture medium whereas flavonoids resulted in increased ACH and 5-HT levels. Conclusion Phenolic acid derivatives and flavonoids were likely the active constituents of daylily flowers and they conferred a similar extent of neuroprotection, but affected the release of neurotransmitters in a different manner.