bluuebunny/crossref_metadata_2025 huggingface dataset:
Strawberry Fruit Composition during the Harvest Season
Authors: Kalt W. , McDonald J.
Published: February 2019

Fruit composition can be affected by genetic and environmental factors during development and ripening. Red-ripe strawberries were harvested at regular intervals during the harvest season to determine how early or later ripening fruit may vary in composition. The cultivars `Cavendish', `Honoeye', and `Kent' were harvested twice weekly over a 3-week period and FW, %DW, and sugar, acid, and anthocyanin pigment content was measured. The study was repeated for 2 years. Fresh fruit weight declined over the harvest period, while the %DW increased in all cultivars. Although the content of sucrose and glucose (mg/g DW) did not vary among the harvest dates, their content was different among the cultivars. Citric and malic acid content (mg/g DW) was lower in the later harvests, although their content was similar among the cultivars. Total anthocyanin content increased and then declined during the harvest season. Pelargonidin 3-glucoside, the major strawberry anthocyanin, was highest in `Honoeye', while cyanidin 3-glucoside content was similar among the three cultivars.
Interspecific Hybrids Originated from Crossing Asian Wild Strawberries (Fragaria nilgerrensis and F. iinumae) to F. xananassa
Authors: Noguchi Yuji , Mochizuki Tatsuya , Sone Kazuyoshi
Published: February 2019

The use of wild species as breeding materials was tried for expanding hereditary variation in strawberry. Some interspecific hybrids setting large fruits with peculiar aroma have been bred by pollination of F. vesca to F. xananassa. Although Asian wild diploid strawberries such as F. nilgerrensis or F. iinumae have not been exploited as a breeding material until the present, the crossing test between cultivated strawberries (8x) and the Asian wild strawberries (2x) were attempted. The interspecific hybrids originated from pollination of F. nilgerrensis or F. iinumae to F. xananassa cv. `Toyonoka' were all sterile pentaploids. By in vitro colchicine treatment of these sterile hybrids for chromosome doubling, many fruiting interspecific hybrids were produced. In particular, some superior hybrids were obtained from `Toyonoka' × F. nilgerrensis. From the results of RAPD analysis, the interspecific hybrids had the fragments specific for both parents. While their morphological characters were close to `Toyonoka', they had some characters from F. nilgerrensis, such as numerous hair on their petioles and peduncles. Their fruits have good characters that are same level of cultivated strawberry about size, Brix, acidity, and vitamin C content. The flesh is soft and skin color is pale pink. The aroma components are resemble F. nilgerrensis, and enrich ethyl acetate. The fragrance of interspecific hybrid like peach is characteristic.
Small Fruit Germplasm Collection in Northeast China
Authors: Finn Chad , Postman Joseph , Thompson Maxine
Published: February 2019

The wealth of small fruit genetic resources present in China is recognized; however, very little collection and subsequent incorporation of this germplasm have taken place. From July to Aug. 1996, we collected small fruit germplasm with Chinese colleagues in northeast China. The collection area was primarily in Heilongjiang and Jilin provinces; from the Russian border (53°N) to the North Korean border and south to 42°N. Collections were made in the Changbai Shan, Xio Hinggan Ling, and Da Hinggan Ling mountain ranges. The primary genera of interest included Rubus, Ribes, Vaccinium, and Fragaria. In addition, species within Corylus, Actinidia, Lonicera, Sambucus, and Schizandra were collected along with ornamental trees, herbaceous perennials, and shrubs when available. Seed was shared with our Chinese colleagues. Collections have been deposited within the USDA-ARS National Plant Germplasm System. The most-promising collections included: an extremely large fruited Rubus crataegifolius population, many populations of Vaccinium uliginosum and V. vitis-idaea from a broad geographic range, large samples of F. orientalis, and a number of populations of the edible Lonicera caerulea. The collected species, collection sites, and observations will be presented.
Biochemical and Molecular Characterization of 18 Agrobacterium vitis Isolates
Authors: Mohamed Fokar , Durham Richard
Published: February 2019

Agrobacterium vitis is the causal organism of crown gall in grapevine. Infection is particularly severe in areas that experience winter damage to vines. Improving resistance to A. vitis will require a detailed knowledge about this organism. In this study, 18 grapevine isolates of A. vitis were collected from different locations near Lubbock, Texas. Isolates were subjected to a phenotypic characterization using 12 biochemical tests, including production of alkali from L-tartrate, production of 3-ketolactose, utilization of citrate, and others. Previously characterized isolates of A. vitis and A. tumefaciens obtained from the American Type Culture Collection served as positive and negative controls in these assays. Isolates were also evaluated for host range, tumor morphology, and opine utilization, and were compared at the molecular level by restriction fragment length polymorphism analysis of the oncogenic regions of the T-DNA plasmid. Although all isolates were able to metabolize tartrate and grow on Roy–Sasser media, there was much variability based on other tests. Twelve of 18 isolates were able to utilize octopine as a sole carbon source. All isolates tested thus far have been pathogenic on tomato and tests on grapevines are underway.
Use of 2n Giant Pollen to Produce Nonaploid Japanese Persimmon
Authors: Tao R. , Ohkuma T. , Tamura M. , Sugiura A.
Published: February 2019

Distribution of pollen diameter of Japanese persimmon cv. Zenjimaru (2n = 6x, × = 15) was determined using pollen grains hydrated with CPW solution supplemented with 0.9 M mannitol. Mean diameter of giant pollen grains (65 μm) was 1.3 times longer than that of normal pollen grains (50 μm). The occurrence of giant pollen was estimated to be about 5% of the pollen population. The hydrated giant pollen grains could be sorted out from normal pollen grains by filtering through a layer of nylon mesh (62 μm). Flow cytometric analysis of nuclear DNA content confirmed that giant pollen was unreduced 2n pollen. 2n giant pollen grains were pollinated to cn. Jiro (2n = 6x) callie and plantlets could be obtained from immature embyros excised from seeds 70 days after pollination.
Effect of Calcium Nutrition on Disease Development and Latent Infection of Bacterial Wilt in Grafted Tomato Seedlings
Authors: Yamazaki H. , Kikuchi S. , Hoshina T. , Kimura T.
Published: February 2019

To control bacterial wilt of tomato, grafting with resistant rootstocks widely prevails in Japan, but the disease has recently occurred even on grafted plants. Concerning this breakdown of resistance, the experiments were conducted to investigate the effect of Ca nutrition on disease development and latent infection of bacterial wilt in grafted tomato seedlings. Three levels of Ca (0.4, 4.4, or 20.4 mm) in a nutrient solution were applied to grafted seedlings (scion: `Momotarou', resistant rootstock: `Hawaii 7998') grown in a phytotron. One week after the Ca treatment, seedlings were inoculated with a 108 cfu/ml suspension of Ralstonia solanacearum by a stem puncture at the basal stem of the rootstock. The disease incidence was recorded for 21 days. In a second experiment, xylem exudates were collected from decapitated scions of the Ca-treated seedlings 5 days after inoculation. Populations of the pathogen in the exudates were counted by plating on a selective medium. Colonies isolated were reinoculated to susceptible seedlings to check the virulence. The high Ca treatment increased leaf and stem Ca contents, and significantly reduced the disease incidence. While Ca concentrations in the xylem exudates increased with the high Ca treatment, the populations of the pathogen in the exudates were high (>109 cfu/ml) even at the high Ca treatment. All the colonies isolated were virulent. These results showed that grafted tomato seedlings treated with a high Ca concentration were highly resistant to bacterial wilt, but latently infected.
Lettuce Response and Nitrate-N Leaching to Water and Nitrogen on Sand
Authors: Sanchez C.A.
Published: February 2019

The low desert region of Arizona is the major area of lettuce (Lactuca sativa L.) production during the winter. Most lettuce is grown on alluvial valley loam and clay loam soils. There is interest in moving some vegetable production onto sandy soils on the upper terraces (mesa) to partially relieve the intensive production pressure currently being placed on land in the valleys. Water and N management is a major concern in coarse-textured soils. Studies were conducted to evaluate the response of crisphead lettuce to sprinkler-applied water and N fertilizer on a coarse-textured soil (>95% sand). The experiments were irrigated using a modified lateral irrigation system that applied five levels of water and five levels of N in specified combinations. Nitrate-N concentrations were determined in samples collected in ceramic suction cups placed below the crop rooting zone. Leaching fraction was estimated by frequent neutron probe soil moisture measurements. Lettuce yield increased with water and N but rates required for maximum economic yield exceeded rates typically required on finer-textured valley soils. These data show the potential for large N leaching losses on this coarse-textured soil.
The Effect of Substrate pH on the Rooting of Rhododendron with Subirrigation
Authors: Holt Thomas , Maynard Brian K. , Johnson William A.
Published: February 2019

Subirrigation is a viable alternative to mist for the cutting propagation of many woody and herbaceous plants. However, poor success has been reported with rhododendron cuttings. This study evaluated the rooting of two Rhododendron cultivars in a subirrigation system maintained at two different levels of substrate pH. Stem cuttings of Rhododendron `PJM' and R. `Catawbiense album' were wounded, treated with Dip `n Grow (1:10 dilution), and rooted in subirrigated perlite subirrigated with tap water (pH 7.5), or tap water adjusted to pH 4.5 with weak sulfuric acid (1N H2SO4). Percent rooting and root ball displacement were recorded after 7 weeks. The pH of the subirrigation system dramatically affected root initiation and development. At pH 4.5 `PJM' cuttings rooted 100% with an average displacement of 7.6 ml; cuttings of `Catawbiense Album' rooted 88% with an average displacement of 12.1 ml. At pH 7.5, `PJM' cuttings rooted 52.5%, with an average displacement of 0.8 ml, while `Catawbiense album' rooted 73% with an average displacement of 2.5 ml. A root ball displacement of ≥3 ml was judged to be commercially acceptable for rooted cuttings of `PJM' rhododendron, ≥4.5 ml for `Catawbiense album'. At pH 7.5 only 15% of the `Catawbiense album' cuttings and none of the `PJM' cuttings produced commercially acceptable rooted cuttings. At pH 4.5, 83% of the `Catawbiense album' cuttings and 93% of the `PJM' cuttings were commercially acceptable. Subirrigation is a suitable method of irrigating rhododendron cuttings during rooting if a low substrate pH is maintained.
A Study of Ice Nucleation and Propagation in Cranberry Plant using Infrared Video Thermography
Authors: Workmaster Beth Ann A. , Wisniewski Michael , Palta Jiwan P.
Published: February 2019

Infrared video thermography has recently been used to visualize ice nucleation and propagation in plants. At the UW–Madison Biotron facility, we studied the formation of ice in various parts of fruit-bearing cranberry (Vaccinium macrocarpon Ait.) uprights. The fruits were at the blush to red stages of ripening. Samples were nucleated at –1 or –2°C with ice-nucleating-active bacteria (Pseudomonas syringae). Following nucleation, samples were cooled to –6°C in ≈1 hour. The following observations were made: 1) When nucleated at a cut end, ice propagated rapidly throughout the stem and into the leaves at a tissue temperature of about –4°C. However, ice did not propagate from the stem through the pedicel to reach the fruit. During the 1 hour after ice propagation in the stem, the fruit remained supercooled. 2) Within the duration of the experiment, leaves could not be nucleated from the upper surface. Ice from the lower leaf surface did nucleate the leaf, and ice propagated from the leaf to the stem and other leaves readily. 3) Both red and blush berries could only be nucleated at the calyx end of the fruit. 4) Red berries supercooled to colder temperatures and for longer durations than the blush berries. 5) In support of our previous studies, red berries were able to tolerate some ice in their tissue. These observations suggest that: 1) The upper leaf surface and the fruit surface (other than the calyx end) are barriers to ice propagation in the cranberry plant; and 2) at later stages of fruit ripening the pedicel becomes an ice nucleation barrier from the stem to the fruit. This may contribute to the ability of the cranberry fruit to supercool.
Screening, Identification, Improvement, and Genetics of Resistance to Bacteria Soft Rot (Erwinia carotovora) Disease of Brassica Vegetables
Authors: Ren Jianping , Dickson Michael H.
Published: February 2019

More than 700 accessions of Brassica vegetables were screened for resistance to bacterial (Erwinia) soft rot disease using a newly developed testing procedure. Dipping a needle in 2-day-old bacterial culture and pricking petioles of plants gave the most-consistent and distinguishable results in both seedling greenhouse and mature plant field tests. High humidity (100%) and warm temperature (higher than 23°C) are the two essential conditions for this test to be successful. So far, immune material has not been found. In B. rapa, less than 7% of the accessions showed some degree of resistance. High correlation was found between seedling greenhouse tests and mature plant field tests. Genetic study showed that soft rot resistance in B. rapa is a quantitative trait. The broad-sense heritability was 60% and narrow-sense heritability was 42% in the tested population. Following three cycles of recurrent selection, the resistance level in cycle three population was improved by 2.4 disease score points (1–9 scale) compared to the original parental population and the disease score of the best line in cycle 3 was 2.7 compared to a susceptible check on which the disease score was 8 under greenhouse conditions. Under field conditions, the best cycle three line scored 2.0 in comparison to the susceptible check, which scored 7. From our study, the recurrent selection works well for improving the resistance level to the soft rot disease in B. rapa.
Randomly Amplified Polymorphic DNA (RAPD) Variation among and within Cultivated and Wild American Ginseng (Panax quinquefolium L.) Populations
Authors: Boehm C.L. , Harrison H.C. , Jung G. , Nienhuis J.
Published: February 2019

The magnitude of genetic differences among and the heterogeneity within cultivated and wild American ginseng populations is unknown. Variation among individual plants from 16 geographically separated, cultivated populations and 21 geographically separated, wild populations were evaluated using RAPD markers. Cultivated populations from the midwestern U.S., the southern U.S., and Canada were examined. Wild populations from the midwestern U.S., the southern U.S., and the eastern U.S. were examined. Polymorphic bands were observed for 15 RAPD primers, which resulted in 100 scored bands. Variation was found within and among populations, indicating that the selected populations are heterogeneous with respect to RAPD markers. The genetic relationships among individual genotypes were estimated using the ratio of discordant bands to total bands scored. Multidimensional scaling of the relationship matrix showed independent clusters corresponding to the geographical and cultural origins of the populations. The integrity of the clusters were confirmed using pooled chi-squares for fragment homogeneity. Average gene diversity (Hs) was calculated for each population sample, and a one-way analysis of variance showed significant differences among populations. Overall, the results demonstrate the usefulness of the RAPD procedure for evaluating genetic relationships and comparing levels of genetic diversity among populations of American ginseng genotypes.
ycled Paper as a Growth Substrate in Container Production of Spi
Authors: Craig Paula , Cole Janet C.
Published: February 2019

Wet Earth (WE) is a recycled paper product being tested as a potential plant growth substrate. It is composed of 80% recycled paper, 18% diatomaceous earth, 1% CaO, and 1% humic acid by volume. Use of WE by commercial growers would reduce demand for both landfill space and for slowly renewable resources such as peat and pine bark. Evidence also suggests that WE reduces nitrate runoff. Objectives included: determining effects of WE on plant growth, examining effects of WE on NO3 and NH4 runoff from container plant production, and determining the chemical and physical properties that characterize WE as a growth substrate. Ratios of pine bark to WE tested were 100% pine bark, 1:3, 1:1, 3:1, and 100% WE by volume. Fertilizer treatments included: 100% of the recommended rate of controlled release fertilizer (CRF), 50% CRF plus 50% liquid fertilizer (LF) and 100% LF. Plant heights, widths, and visual quality ratings were obtained monthly throughout the 16-week experiment. Leaf, shoot and root dry weights were determined at harvest. Nitrogen content of roots, shoots, and substrates were determined at planting and harvest, while NO3 and NH4 content of leachate was determined at each irrigation. All substrates were analyzed at planting and harvest for pH, soluble salts, exchangeable cations, and CEC. Changes in volume, bulk density, porosity, and air space were also measured. Plant size and quality varied significantly between substrate mixes. Mortality was significantly higher in mixes containing 75% and 100% WE. Changes in volume, bulk density, and percent air space were also significant and inversely related to WE concentration.
OSU Douglas County Demonstration Farm
Authors: Maul Jerry
Published: February 2019

The demand for horticultural information from the OSU Extension Service is sought by both commercial fresh-market vegetable growers and noncommercial clients. Educational programs at the Demonstration Farm were designed to meet the needs of these two diverse groups. At the request of local growers, vegetable trials were established to evaluate the large number of new varieties that come onto the market every year. Since 1987, nearly 250 varieties of eggplant, melons, peppers, squash, sweet corn, and tomatoes have been evaluated for their adaptability to Douglas County's Mediterranean climate and growing conditions. Annual reports on the performance of the varieties are shared with county vegetable growers and Extension Agents throughout Oregon. Many of the vegetables for the trials are grown as bedding plants in the Demonstration Farm greenhouses. A greenhouse program was established to offer Master Gardeners the opportunity to participate in all of the cultural aspects of bedding plant production. This includes; seeding, transplanting, pinching, watering, and fertilizing. When planting season arrives, Master Gardeners help transplant the seedlings to the trial plots. An average of 40 Master Gardeners have participated in the greenhouse and trial program each year, since their inception in 1987. An average of 300 people attend the field days every summer to tour the vegetable trials. An outdoor gardening class, “Summer In The Garden,” is offered to the general public every summer. An average of five sessions are held in July and August on a variety of topics related to vegetable culture, pest control, and new varieties. The sessions are taught by the Horticulture Agent with the assistance of Master Gardeners. Attendance has averaged 25 students annually.
Postharvest Quality Characteristic of Unrooted Geranium Cuttings in Response to Storage Conditions and Fungicides
Authors: Childs K.G. , Nell T.A. , Barrett J.E. , Clark D.G.
Published: February 2019

Experiments were conducted to evaluate the development of stored unrooted Pelargonium × hortorum `Designer Bright Scarlet' cuttings. Treatments included storage temperature and duration and pre-storage fungicide application. Cuttings were harvested from stock plants treated with water or fungicide (Iprodione), and were stored at 60°F and 75°F for 2, 4, and 6 days. Leaf yellowing data (visual quality rating, chlorophyll fluorescence, and total chlorophyll content) were measured at the start of propagation and 7 days later. At both dates, cuttings stored but not treated with fungicide displayed more leaf yellowing after storage at 75°F for 4 and 6 days or at 60°F for 6 days compared to fungicide-treated cuttings and non-stored controls. Cutting quality was not affected by 2 days of storage, regardless of storage temperature or fungicide treatment. Fungicide-treated cuttings had less leaf yellowing after storage for 6 days at 60°F or 75°F compared to untreated cuttings, but they had more leaf yellowing than no storage controls after 7 days of propagation. Root number and root length of each cutting was measured at 14 days after start of propagation. Cuttings treated with fungicide displayed better adventitious root formation after all 4- and 6-day storage treatments compared to cuttings stored but not treated with fungicide.
Increase of Easter Lily Postharvest Flower Longevity with PBA Application to Young Flower Buds
Authors: Pemberton H. Brent , Wang Yin-Tung , McDonald Garry V.
Published: February 2019

Case-cooled bulbs of Lilium longiflorum `Nellie White' were potted on 4 Dec. 1995 and forced to flowering using standard growing procedures. Plants were illuminated from shoot emergence to visible bud with supplemental high-intensity-discharge sodium vapor light at 70 μmol·m–2·s–1 from 1700 to 2200 HR each day. When the first primary flower bud (first initiated flower bud most proximal on the shoot) was 5 to 7 cm long, each plant was treated with 3 ml of either de-ionized water or 500 mg·liter–1 6-(benzylamino)-9-(2-tetrahydropyranyl)-9H-purine (PBA). Sprays were directed at the flower buds and associated bracts. When the tepals on the first primary flower bud split, plants were placed at 2°C in the dark for 0, 4, or 21 days. After storage, plants were placed in a postharvest evaluation room with constant 21°C temperature and 18 μmol·m–2·s–1 cool-white fluorescent light. The first three primary flowers on PBA-treated plants lasted significantly longer than corresponding flowers on control plants, but there was no difference between flowers at the fourth and fifth positions. Also, the total postharvest life of the five primary flowers on PBA treated plants was 3 days longer than those on control plants. Storage time inversely affected the postharvest longevity of the first three primary flowers, but had no effect on the longevity of the fourth or fifth primary flowers or total postharvest life of the five primary flowers. There were no significant interaction effects between PBA treatment and storage duration on primary flower longevity.
Effect of Sucrose and PEG Concentration on Embryo Maturation and Hyperhydration in Date Palm Suspension Cultures
Authors: Al-Matar Shatha Matar , El-Nil Mostafa M. Abo , Al-Khairy Jameel , Klingaman Gerald
Published: February 2019

Cell suspension cultures of four date palm cultivars were established, namely, Niboat Saif, Madjhool, Sukarri, and Berhi. In this study, two factors were tested for their effect on embryo maturation and hyperhydration. The effect of sucrose concentration was assessed by inoculating 0.5 g of embryogenic callus into a liquid MS basal medium supplemented with 10 mg/L inositol, 3 mg/L glycine, 20 mg/L glutamine, and 0, 20, 30, 40, 50 g/L sucrose. Polyethylene glycol (PEG) concentration effect on embryo maturation and hyperhydration was tested. PEG (molecular weight 7000–9000) was added at concentrations of 0, 10, 30, and 60 g/L to the date palm suspension cultures. Cultures were examined and subcultured every 3 weeks for 2 months. Embryos formed were then transferred to a solid MS medium supplemented with 10 mg/L inositol, 3 mg/L glycine, 5 mg/L glutamine, and 30 g/L sucrose. The number of embryos germinated from each treatment was counted to compare cultivar differences. Preliminary data suggests that the medium containing 30 g/L sucrose is most effective for embryo maturation, and those embryos germinated when transferred to a solidified MS medium. The study found that incorporating PEG into the medium reduced the hyperhydration of date palm tissues. The various cultivars reacted differently to the treatments employed.
Pollination and Fruit Set of Pumpkins in Growers' Fields in New York's Capital District
Authors: Wien H. Chris , Riggs Dale
Published: February 2019

Reports of sharply reduced feral bee populations (Apis mellifera) due to harsh winters and prevalence of several bee diseases have raised concerns that pollination and fruit set in pumpkin fields will be adversely affected. In 1995 and 1996, five and eight pumpkin (Cucurbita pepo) fields, respectively, were inventoried on three occasions per season for pollinator activity and percent fruit set. Pollen removal from male flowers was determined visually using a rating scale, while deposition of pollen on stigmata of female flowers was judged by rating fluorescence of pollen on the stigmatic surface under a “black light.” Samples were taken from 15 to 30 locations in each field, and female flowers tagged. These were considered set if they had enlarged to fist size within 14 days. In both years, the amount of pollen remaining on male flowers was negatively correlated with female flower fluorescence ratings. Neither pollen on male flowers nor stigma fluorescence were significantly correlated with percent fruit set. Fifty-two percent of tagged flowers set fruit in both years, with a range of 24% to 84%, and 17% to 78% in 1995 and 1996, respectively. Presence of bee hives in or near the fields had no effect on fruit set. The results indicate that the pollen removal and deposition ratings used were not reliable for predicting fruit set in farmers' fields. In these 2 years, bee hives were not needed in the sampled fields.
Photoperiod and Temperature Interact to Affect Viola × wittrockiana Gams. Development
Authors: Erwin J.E. , Warner R. , Smith T. , Wagner R.
Published: February 2019

Viola × wittrockiana Gams. cvs `Delta Pure Rose' and `Sorbet Yellow Frost' were grown under different photoperiod and temperature treatments (12–24 ± 2°C) for different lengths of time at different stages of development during the first 6 weeks after germination. Plants were grown with ambient light (≈9 hr) at 16°C before and after treatments. Days to anthesis and leaf number were lowest when plants were grown under night interruption from 2200–0200 hr (2 μmol·m–2·s–1 from incandescent lamps) and daylight plus continuous light (100 μmol·m–2·s–1 from high-pressure sodium lamps) for `Sorbet Yellow Frost' and `Delta Pure Rose', respectively. Days to anthesis decreased as temperature increased from 12 to 24°C. Plant height and internode elongation were greatest and least in the night interruption and continuous light treatments, respectively. Branching decreased as temperature increased from 12 to 24°C. Implications of these data with respect to classification of Viola × wittrockiana flower induction and development of prefinished seedlings is discussed.
Annual Growth and Development of Scilla peruviana
Authors: Azizbekova Naza , Roberts Christia M. , Butland Stefanie , Ellis Brian
Published: February 2019

Scilla peruviana is a bulbous plant whose distribution extends from South Africa, into Europe and Asia. It belongs to the family Liliaceae (subclass Monocotyledonae). S. peruviana is an attractive floral species with excellent commercial potential, but it does not produce many bulblets and its multiplication rate is very low. Increasing the multiplication rate, and regulation of its growth and development, cannot be achieved without knowledge of its basic patterns of ontogenesis. We studied the annual growth and development of S. peruviana, from initiation until differentiation, giving special attention to cytological changes at the apical meristem. We also investigated the cytophysiological changes occurring in scales during ontogenesis. Two generations of daughter bulbs are present in each mother bulb. Flowering of the mother bulb coincides with vegetative development of the apical meristem of the primary daughter bulb (March-April). During gradual senescence of leaves and roots of the mother bulb, the apical meristem of the primary daughter bulb undergoes a transition from vegetative to prefloral development (June). Intensive flower organ differentiation occurs in the daughter bulb during the mother bulb's rest period (July–August). Initiation of the apical meristem of the secondary daughter bulb occurs within the primary daughter bulb, which is itself enclosed within the mother bulb (August). The development of the apical meristem of a daughter bulb, from its initiation until flowering, thus occurs without interruption and takes ≈20 months. By modifying external factors such as temperature and growth regulators, we can now control time of flowering and increase the multiplication rate of S. peruviana.
Rapid Screening of Rhizobacteria for Suppression of Rhizoctonia Damping-off
Authors: Becker J.O , Schuch U.K.
Published: February 2019

A rapid screening system was developed to identify plant-beneficial rhizobacteria useful in protecting nursery seedlings against damping-off caused by Rhizoctonia solani. Ornamental and agricultural crops were planted into 100 soil samples that were collected from various fields throughout California. More than 7000 bacterial strains from the rhizosphere of these crops were isolated and tested in vitro for antibiosis against R. solani AG4. In a second tier, 600 active strains were tested in planting trays seeded with radish (Raphanus sativus `Cherry Belle'). Each planting cell filled with commercial potting mix contained millet-grown R. solani inoculum in the center and eight radish seeds at the periphery. Bacteria were cultured for 24 hr at 25°C in 10% tryptic soy broth and were applied as a drench at 1 × 107 cfu/cc to each cell. Trays were incubated in a growth chamber at 21°C and a 10-hr photoperiod. Post-emergence damping-off occurred within 8 to 9 days after planting, and no further losses were observed after 14 days. Approximately 0.5% of the original 7000 bacterial strains tested reduced damping-off significantly. Fifteen bacterial strains controlled Rhizoctonia damping-off by 30% to 60% compared to the non-treated control.
Evaluation of Garlic Germplasm for OYDV and LYSV Infection using Dot Blot ELISA
Authors: Myers J. Michele , Simon Philipp W. , Fonseca M.E.N. , Boiteux Leonardo S.
Published: February 2019

Garlic is an asexually propagated crop in which the greatest yield losses are attributed to virus infection. Currently, virus-free garlic is produced through shoot tip culture, and there are no known naturally occurring resistant clones. This study evaluated garlic germplasm (propagated from typical bulbs, not shoot tips) for incidence of two viruses known to infect garlic (onion yellow dwarf virus, OYDV and leek yellow stripe virus, LYSV) using dot blot ELISA. Young leaf tissue was collected from 173 garlic clones. For 118 clones, plants grown in the field from typical bulbs only were evaluated. For 55 clones, plants grown in the greenhouse from both bulbs and topsets (bulbils) were evaluated. Topsets are small bulbs that are produced in the inflorescence of stalking garlic. Each clone was tested at least three times for incidence of both viruses. In field grown bulbs, we found that 70% were infected with OYDV and 85 % were infected with LYSV. In greenhouse grown samples, incidence of OYDV was generally higher in plants from topsets than those from bulbs while no differences were seen for LYSV. Three clones were negative for both viruses and might be a useful source of resistance that can be used in producing virus resistant lines.
Pod Development Dynamics and Culture Response in Lima Beans
Authors: Liao Boshou , Kitto S.L.
Published: February 2019

In this study, the pod development dynamics and culture response in lima bean (Phaselous lunatus L.) were investigated. The average percentage of flowers to form pins was 17.5%. Pin length and width (mm), and weight (g) were all highly correlated with the days after pollination (DAP), with correlation coefficients of 0.98, 0.99 and 0.97, respectively. Pods grew relatively faster between 12 and 20 DAP, and reached their maximum length at about 35 DAP. Explants from pods of 5, 10, 15, 20, 25 DAP were cultured onto B5 medium containing BA (2 mg/L), kinetin (0.5 mg/L), 2,4-D (1 mg/L) or NAA (1 mg/L), sucrose (5%), and agar (0.7%). Soft calli only formed from the cut region on the seed coat or the suspensor attachment site of 5 and 10 DAP seeds. The 15 DAP explants were cultured as embryos (cotyledons 2 mm in length), and no callus was observed on them after 30 days of culture when they became brown. Twenty and 25 DAP embryos initiated calli and/or organ-like structures on the abaxial surface of cotyledons or embryo axes after 20 days of culture.
Testing a Power Duster for Pollination of `McIntosh' Apples
Authors: Schupp J.R. , Koller S.I. , Hosmer W.D.
Published: February 2019

This study was undertaken to test the efficacy of a power duster for supplemental pollination of `McIntosh' apple trees, where lack of nearby pollinizing cultivars was thought to be a limiting factor to productivity. The pollen duster was ineffective in increasing fruit set, fruit size, or seed number in fruits on limbs that were covered with spun-bonded rowcover material prior to bloom. Applying supplemental pollen to open-pollinated `McIntosh' trees had no effect on fruit set, yield, fruit size, or seed number, regardless of pollen dose, timing, or number of applications. Dispersal of supplemental pollen with a power duster appears to be an inefficient method of pollinating apple trees.
Development and Abortion of Flowers in Capsicum annuum Exposed to High Temperatures
Authors: Erickson Ami N. , Markhart Albert H.
Published: February 2019

Reduction of floral number in Capsicum annuum has been observed during growth at high temperature. To determine whether decreased flower production or increased flower abscission is a direct response to high temperatures or a response to water stress induced by high temperatures, we compared flowers and fruit produced and flowers aborted to leaf growth rate, osmotic potential, stomatal conductance, and chlorophyll fluorescence of two cultivars. To determine the stage(s) of floral development that are most sensitive to high temperatures, flower buds were wax-embedded and examined at each stage of development during heat treatment. Rate of floral development also was examined. At first visible floral bud initiation, plants were transferred to each of three controlled environment growth chambers with set temperatures and vapor pressure deficits (VPD) of 25°C, 1.1 kPa; 33°C, 1.1 kPa; and 33°C, 2.1 kPa. Flower bud production and leaf growth rate were not significantly affected by high temperatures. Pepper fruit set, however, was inhibited at 33°C at either VPD. Preliminary water relations data suggested that water potentials were more negative under high temperature conditions. Differences in leaf fluorescence were statistically significant for temperature treatments, but not for VPD. Temperature is the primary factor in the decrease of fruit production in pepper. Decreased production is due to flower abortion and not to decreased flower initiation or plant growth.
Rooting Performance of Hydrangea Cutting Types in Propagation Media Containing Coal Bottom Ash
Authors: Pitchay Dharmalingam S. , Bearce Bradford C.
Published: February 2019

Rooting performance was evaluated for three different hydrangea (Hydrangea macrophylla Thunb. `Blaumeise Lace Cap') cutting types in propagation media containing peat:sand amended with 0%, 25%, 50%, and 100% coal bottom ash (CBA) sieved through 2-mm mesh. Electrical conductivity (EC) values of all media were in acceptably low ranges, whereas pH was suboptimal in all but 100% CBA, ranging from 3.8 to 4.6 vs. 6.0 to 6.75 for 100% CBA. Available Ca was significantly higher at up to 189 mg·kg–1 in the 100% CBA. Rooted cuttings were analyzed for root counts and dry mass. Terminal tip cuttings produced 96.1 mean roots/stem compared to butterfly cuttings (76.4) and single-eye cuttings (60.7), and there was no significant difference in root dry mass among the different cutting types. Propagation media containing 50% CBA produced greater numbers of roots/stem (99.89 and 89.59, respectively). The dry mass of roots/stem was significantly higher in media with 100% CBA. Root numbers per cutting were higher in terminal tip cuttings grown in 50% and 100% CBA and butterfly cuttings in 50% CBA. On the other hand, dry mass per cutting was higher in 100% CBA as compared to the rest, except for the terminal tip and butterfly cuttings in 50% CBA. The higher pH and Ca concentration may be factors causing the better rooting performance in 100% CBA.
Adventitious Shoot Formation on Hypocotyl Explants of Antirrhinum majus L.
Authors: Schroeder Kenneth R. , Stimart Dennis P.
Published: February 2019

One-centimeter hypocotyl explants from 2-week-old Antirrhinum majus L. (snapdragon) seedlings germinated and grown in vitro under 12-h cool-white fluorescent light and 12 h dark or 24 h dark were placed on Murashige and Skoog (MS) medium containing 0, 0.44, 2.22, 4.44, 8.88, or 44.4 μM N6-benzyladenine (BA). Cultures were maintained under the light/dark regime at 25°C. After 2 weeks, adventitious shoots were counted. A shoot was considered adventitious and counted if a stem and leaf developed. Shoots developed along the entire length of the hypocotyl sections. Mean shoot production per hypocotyl explant ranged from 2.4 to 6.1 shoots when seedlings were germinated and grown in 24 h darkness and 2.2 to 10.9 shoots when started in the light/dark regime. Highest shoot counts were attained /from hypocotyl explants when seedlings were germinated and grown under the light/dark regime for 2 weeks and transferred to 2.22, 4.44, or 8.88 μM BA. Shoot development appeared normal at the 2.22 and 4.44 μM level, while at 8.88 μM BA, development was slightly abnormal along with slightly more callus production.
Short-term Controlled-stmosphere Storage of Tomatoes Improves Marketing Options
Authors: Rushing James W.
Published: February 2019

Mature-green tomatoes stored up to 8 weeks at 11.5°C under 4% oxygen with no accumulation of carbon dioxide above ambient had reached turning stage of color by the end of the storage period. Control tomatoes stored at identical temperature without CA quickly turned red and were unmarketable after 4 weeks due to overripenessand high incidence of decay. Tomatoes held under CA for 8 weeks and then transferred to 20°C without CA ripened normally to full-red color within 10 days with less than 10% decay and no apparent mealiness or other symptoms of chilling injury. Weight loss from tomatoes stored under CA increased with storage time, but, after 8 weeks, the fruit still did not have noticeable shrivelling and visual appearance was excellent compared to tomatoes purchased from a local supermarket. Results of this research suggest that short-term CA storage is a feasible method of expanding the market window for tomatoes. This could be particularly useful for production regions such as South Carolina, where the harvest is practically completed within a 3-week window and low prices often prevail during the harvest period.
Seasonal Fluctuations of Sugar Accumulation and the Activities of Related Enzymes Accompanying Maturation of Different Tomato Cultivars
Authors: Islam Md. Shahidul , Khan S. , Matsui T.
Published: February 2019

Seasonal fluctuations of carbohydrate levels and compositions and the activities of related enzymes of three cultivated tomato (Lycopersicon esculentum Mill. cv. Lady First, Momotaro, and Minicarol) cultivars were examined at 45-days interval with seven different sowing in the relatively warm climate of Japan. Fruits picked on early winter to spring seasons had higher sugar concentrations compared to hot season. Fructose and glucose in nearly equal amounts were the predominant sugar in all the seasons. Sucrose was present in trace quantities, but cherry cultivar Minicarol accumulated higher levels than the other two large-fruited types.

Acid invertase (EC 3.2.1.26) was highest at red stage during December to April, while fruit matured during May to August had lowest activity. The activity levels of soluble invertase were predominant compared to cell wall-bound fraction. The sucrose synthase (EC 2.4.1.13) showed highest activity in rapidly growing fruits followed by a very low activity with fruit maturation. Sucrose synthase showed the higher activity during November to February, and almost low activity during all the experimental periods. The sucrose phosphate synthase (EC 2.4.1.14) also showed higher activity during October to February, but the activity levels did not change drastically throughout the fruit development. The results substantiate the conclusion that, in all the planting seasons, acid invertase is a principal enzyme in the process of tomato fruit ripening and during early stage of tomato fruit development, sucrose synthase is the dominant enzyme, which, in turn, plays a part in regulating the translocation of sucrose into the fruit.
Enhanced Control of Powdery Mildew of Greenhouse Roses using Piperalin Tank-mixed with Quaternary Benzophenanthridine Alkaloids
Authors: Roll Michael J. , Newman Steven E. , Harkrader Ronald J.
Published: February 2019

A formulation of quaternary benzophenathridine alkaloids (QBA) was combined with piperalin as a tank mix. The QBA was applied at 150 mg/L and piperalin, at the labeled rate, was applied as a spray application to greenhouse roses infected with Sphaerotheca pannosa var. rosae (powdery mildew). Copper sulfate pentahydrate and fenarimol were also applied to mildew-infected plants within the same greenhouse at their respective label rates for comparison. Initial infection for the QBA/piperalin combination spray was 45% of the leaflet surface area, 3 days after application the infection was reduced to 10%, 6 days after application infection was reduced to 5%, and 14 days after application the infection remained at 5%. Initial infection for a QBA application without piperalin was 25% of the leaflet surface area. Three days after application, the infection was reduced to 15%; 6 days after application the infection remained at 15%; and 14 days after application, the infection was reduced to 10%. The data reveals that the QBA/piperalin combination gives a short-term as well as a long-term fungicidal and fungistatic activity.
Comparative Studies on Hanabusaya asiatica and Its Allied Groups Based on Randomly Amplified Polymorphic DNA (RAPD) Analysis
Authors: Lim Hak-Tae
Published: February 2019

The phylogenetic relationships between Korean endemic, Hanabusaya asiatica, and its allied groups, including four genera and nine species, were investigated at the DNA level using randomly amplified polymorphic DNA (RAPD) method. Ten primers out of 80 primers (10-mer) screened gave rise to very high polymorphism (99%) in all of the tested plants, producing 153 randomly amplified DNA fragments. H. asiatica was differentiated from its allied groups at the 0.62 of similarity index of RAPDs. This results were in accordance with previous classification based on palynological studies. It was confirmed that H. asiatica could be placed into Korean endemic and suggested that RAPD technique be used as an additional method of phylogenetic relationship for plant systematics.
Inheritance of Male Sterility in Lesquerella fendleri
Authors: Dierig D.A. , Tomasi P.M. , Coffelt T.A.
Published: February 2019

Lesquerella fendleri (Gray) Wats., Brassicaceae, is a potential oilseed crop native to the southwestern U.S. The seed oil contains hydroxy fatty acids, similar to castor. Unique properties of the oil, along with coproducts, allow additional applications that would not be in competition with castor. Plants with vestigial anthers were discovered in a bulk population growing in the greenhouse in 1993. The inheritance of the trait was investigated the following three crop seasons. Crosses were made among sterile and fertile plants and reciprocals among fertile plants. Chi-square results indicate the male sterility trait is expressed by a recessive nuclear gene with cytoplasmic influence restoring fertility. Cytoplasmic male sterile lines can be utilized for development of hybrids. Development of lines without male sterility should lead to higher yields than current bulk populations of lesquerella. Hybrid plants and higher yields will enhance the commercialization potential of this new, alternative crop.
Zinc Uptake by Pelargonium × hortorum Grown in Shredded Tire Rubber-amended Media
Authors: Baqir Mohammad , Harkess Richard L.
Published: February 2019

On 2 Feb. 1996, rooted cuttings of Pelargonium × hortorum L. H. Bailey cvs. Tango and Blues were planted in 750-cm3 (14 cm in diameter) pots containing peatmoss mixed with shredded tire rubber (2–6.0 mm particle size) at 0%, 20%, 40%, 60%, or 80%. Plants were irrigated by hand, drip, or ebb-and-fl ood, and were arranged in a split-plot experimental design. A wetting agent (Aqua Gro 2000 L, Aquatrols Corporation, Cherry Hill, N.J.) was mixed at the rate of 6 ml per 3750 ml of water and 120 ml of solution was applied to each plant. Greenhouse studies indicated that geraniums could be grown successfully in media containing up to 20% shredded tire rubber by volume when irrigated by hand. Plants grown in media containing more than 20% rubber were observed to be slow-growing and chlorotic. Tissue analysis of the plants indicated significantly increased levels of zinc in plants grown in media containing high percentages of rubber. Geraniums grown in media containing 80% rubber and irrigated using ebb-and-fl ood benches had the significantly highest levels of foliar zinc. Media porosity, percent air space, and bulk density increased, while water holding capacity decreased with increasing amounts of shredded tire rubber added to the media.
The Evolution of Capsaicinoids during Fruit Development of Three Varieties of Hot Peppers
Authors: Contreras-Padilla Margarita , Yahia Elhadi M.
Published: February 2019

Hot chile peppers are the main element that characterizes the Mexican cuisine and culture for at least the past 8 centuries. The components responsible for chile hot flavor, capsaicinoids, are synthesized through the shikimic acid pathway. Their degradation is thought to be aided by the action of peroxidases. This work describes the evolution of capsaicinoids during the development of the fruit in three varieties of hot chile widely used in Mexico: `Habanero', `Arbol', and `Piquin', and its relation with the activity of peroxidases in these fruits. Plants were seeded and transplanted in a greenhouse and fruit were harvested after 10, 20, 30, 40, 50, and 60 days from fruit set. At 60 days from fruit set fruit were completely red and senescent. Total capsaicinoids, capsaicin, and dihidrocapsaicin were detected and quantified using HPLC. The activity of peroxidases was followed using spectrophotometry. Capsaicinoids were higher in the fruit of `Habanero', followed by `Arbol', and then by `Piquin'. Capsaicin was higher than dihidrocapsaicin in the three varieties. Capsaicinoids, capsaicin, and dihidrocapsaicin increased continuously and reached a peak at 50 days after fruit set in the varieties `Habanero' and `Arbol' and after 40 days in `Piquin', and then started to decline. Peroxidases had a maximum activity at pH 6.0, ≈1.0 mM of capsaicin, and 1.0–1.5 mM of H2O2. The activity of peroxidases was slightly high after 10 days from fruit set, decreased, and started to increase again after 50 days from fruit set, which might be related to the evolution of the capsaicinoids.