bluuebunny/crossref_metadata_2025 huggingface dataset:
Fruit Cracking of a Susceptible, an Intermediate, and a Resistant Sweet Cherry Cultivar
Authors: Lane W.D. , Meheriuk M. , McKenzie D.-L.
Published: February 2019

Fruit were studied to determine if anatomical and physiological features explain the difference in susceptibility to rain-induced cracking of the sweet cherry (Prunus avium L.) cultivars Sue (resistant), Lapins (moderately resistant), and Van (susceptible). Water uptake as a percentage of fruit weight at cracking tended to be high in `Sue', medium in `Lapins', and low in `Van' and was related to the percentage of cherries remaining sound after 4 hours of immersion, suggesting that this trait is a factor in determining resistance. Mesocarp cells of `Sue' were more rectangular in section than those of the other cultivars. Skin elasticity and thickness of the cuticle did not explain resistance of `Sue' to cracking. Magnesium, copper, and phosphorus mineral contents were not related to cracking susceptibility, but the content of calcium, which influences cell wall integrity, in the epidermis of `Sue' was lower than in `Van'. Calcium content was not different in the hypodermal cells of the two cultivars. None of the anatomical features examined in this study explain the resistance to fruit cracking of `Sue'.
Optimization of Media Constituents for Shoot Regeneration from Leaf Callus Cultures of Decalepis hamiltonii Wight. & Arn.
Authors: George Jacob , Bais Harsh Pal , Ravishankar G.A. , Manilal P.
Published: February 2019

Response surface methodology was utilized in statistical optimization of three quality factors (the number of multiple shoots, shoot length, and number of leaves) pertaining to regeneration of plantlets from leaf calli of Decalepis hamiltonii Wight. & Arn. (swallow root). The variables evaluated were the levels of sucrose, BA, and NAA each at two different concentrations. Response surfaces for shoot length and multiple shoot number were useful in achieving optimal levels of media constituents and in understanding their interactions, but response surfaces for number of leaves were not. The data indicate that sucrose, BA, and NAA levels may be manipulated to increase or decrease quality factors chosen. This approach may be useful in developing a micropropagation protocol for D. hamiltonii. Chemical names used: benzyladenine (BA); napthaleneacetic acid (NAA).
An Economic Analysis of Soilless Culture in Gerbera Production
Authors: Grafiadellis I. , Mattas K. , Maloupa E. , Tzouramani I. , Galanopoulos K.
Published: February 2019

The financial effectiveness of the soilless culture system (SCS) of gerbera (Gerbera jamesonii Bol. ex Adlam.) production was compared with that of the soil culture system in heated greenhouses in northern Greece. Evaluation was based on budgeting procedures that assumed a project life of 9 years. The decision to accept or to reject the investment was based on the following criteria: 1) net present value analysis (U.S. $18,414), 2) benefit/cost ratio, and 3) risk exposure ratio. The soilless culture system, particularly the plastic bag system using perlite media, was more profitable. Application of sensitivity analysis illustrated the significance of product price and discount rate in determining the accrued benefits.
003 Viruses Associated to Alstroemeria Varieties and Epidemiology of Tomato Spotted Wilt in the Cultivar Rosario
Authors: Gutièrrez-Estrada Arcenio , Zavaleta-Mejl̀a Emma , Mora-Aguilera Gustavo
Published: February 2019

Viruses associated to eight Alstroemeria varieties and the relationship of thrips density and environmental factors with Tomato Spotted Wilt (TSW) intensity as well as the TSW effect on yield were studied in `Rosario' in Central Mexico. Using hosts range the viruses detected were Tomato Spotted Wilt Tospovirus (TSWV), Impatiens Necrotic Spot Tospovirus (INSV), Alstroemeria Mosaic Potyvirus (AlMV), Alstroemeria Streak Potyvirus (ASV), Arabis Mosaic Nepovirus (ArMV) and Cucumber Mosaic Cucumovirus (CMV). With serology, the presence of TSWV was confirmed in `Jubilee', `Rosario', and `Regina'; INSV in `Anabel', `Jubilee', and `Red Sunset'; and AlMV in `Rosario', `Red Sunset', `Rosita', `Yellow King', `Jubilee', and `Rojo Sangria'. TSWV and AlMV were found coinfecting `Rosario' plants. Five percent of plants were serologically positive to TSWV in the first flower harvest (25 Jan.-5 Apr.), 10% in the second (12 Apr.-21 June), and third (5 July-13 Sept.) and 18% in the last harvest (24 Sept.-6 Dec.). The highest peak density of thrips (520 to 630 individuals per sticky trap) were registered when the maximum temperature was higher than 35 °C and the relative humidity was between 40% to 60%. However, such peak density was not correlated with a significant increase of TSW incidence. Number and quality of inflorescences and the stem growth rate were significantly higher (P = 0.05) in plots with asymptomatic plants than that with plants showing putative symptoms of TSW.
006 Susceptibility of Forty-six Cultivars of Lisianthus to Fusarium Crown and Stem Rot
Authors: Harbaugh Brent K. , McGovern Robert J.
Published: February 2019

Fusarium crown and stem rot, caused by Fusarium avenaceum, is a serious disease of lisianthus, Eustoma grandiflorum Raf. (Shinn.). While more than 80 new cultivars of lisianthus have been released for sale in the United States in the past decade, there is a lack of information on their susceptibility to this pathogen. Forty-six cultivars of lisianthus were evaluated for resistance to F. avenaceum. Cultivars were grouped according to blue/purple, pink, or white colors and evaluated within their color class. Although all cultivars evaluated were susceptible to F. avenaceum, partial resistance was observed as indicated by differences in the length of time to symptom expression and in the frequency of diseased plants. `Ventura Deep Blue' and `Hallelujah Purple' (25%) in the blue group, `Bridal Pink' (23%) in the pink group, and `Heidi Pure White' (53%) in the white group had the lowest frequency of diseased plants at 55 days after inoculation. In 21 of the 46 cultivars, 80% to 100% of the plants expressed symptoms at 55 days after inoculation. Screening cultivars for resistance to F. avenaceum is the first step to breeding and developing resistant cultivars. These results also can be useful to growers who could select cultivars that express some level of resistance as an aid in management of this disease until more resistant cultivars are released.
012 Management of Powdery Mildew on Flowering Dogwood with Soybean Oil
Authors: Deyton Dennis E. , Sams Carl E. , Windham Mark T.
Published: February 2019

Field-grown dogwood trees in a commercial nursery were sprayed with 0%, 1%, or 2% soybean oil emulsified with Latron B-1956 at 2-week intervals from 10 June until 19 Aug. 1998. In 1999, dogwood trees were sprayed with 0%, 1%, 1.5%, 2%, or 2.5% emulsified soybean oil at 2-week intervals from 22 June until 26 Aug. The trials had treatments arranged in randomized complete-block designs with eight trees per block and six and four replications in 1998 and 1999, respectively. Disease severity of powdery mildew was estimated using the following scale: 0 = healthy, 1 < 2%, 2 < 10%, 3 < 25%, 4 < 50%, 5 > 50%, and 6 = 100% of foliage with symptoms or signs of powdery mildew. In 1998, trees sprayed with soybean oil had higher net photosynthesis rates and more caliper and height growth than control trees. Untreated trees and ≈25% of foliage infected with powdery mildew on 8 July, while trees sprayed with 1% or 2% soybean oil had about 2% of leaves infected. In 1999, the powdery mildew was already present on foliage (wet spring) when the first application of oil was made. Repeated sprays of soybean oil did not reduce the incidence of powdery mildew. Thus, soybean oil appeared to provide protective control of powdery mildew but not curative control of a heavy infestation of the fungi. Photosynthesis was increased by soybean oil for the first month of spraying in 1999, but did not differ after that. Repeated applications of even the high rates of oil did not cause phytotoxicity.
013 Investigations of Curative and Peventive Control Strategies for Fairy Ring Disease in Turfgrass
Authors: Fidanza M. , Colbaugh P. , Couch H. , Elliott M. , Davis S.
Published: February 2019

Fairy ring has become a troublesome and persistent disease on golf course putting greens and other turf areas in most regions of the United States. Many basidiomycete fungi are associated with this destructive disease in turfgrass. Recent widespread epidemics of fairy ring have led investigators to examine possible management and control options. Curative approaches include topical flutolanil fungicide applications in conjunction with soil surfactants, the application of flutolanil under high-pressure injection, and the use of nitrogen fertility programs. These curative programs were effective at suppressing visual symptoms and turfgrass injury. A preventive approach evaluated repeat applications of flutolanil plus a soil surfactant prior to disease development. This preventive program was effective at eliminating visual disease symptoms on bermudagrass putting greens. Information presented will review results from field research studies conducted over the past 3 years in Florida, North Carolina, Ohio, Texas, and Virginia.
014 Effects of Preemergence Herbicides on Weeds and Eighteen Containerized Crops
Authors: Stamps Robert H. , McColley Daniel W.
Published: February 2019

Five preemergence herbicides (prodiamine 0.5 G, prodiamine 65 WDG, dithiopyr 0.27 G, thiazopyr 2.5 G, and oxyfluorfen + pendimethalin 3 G) were evaluated for weed control and crop safety on 18 plants (Acer rubrum, Agapanthus africanus, Asparagus densiflorus, Camellia sasanqua, × Cupressocyparis leylandii, Cycas revoluta, Galphimia gracillis, Gelsemium sempervirens, Illicium parviflorum, Lantana camara, Loropetalum chinense, Myrtis communis, Ophiopogon jaburan, Plumbago, Quercus virginiana, Rhododendron, Viburnum suspensum, and Zamia floridana. Herbicides were applied at 1.7 kg a.i./ha, except for oxyfluorfern + pendimethalin, which was applied at 3.4 kg a.i./ha. Treatments were applied twice at 4-month intervals. Untreated and weed-free controls were used to determine herbicide effects on weeds and crops, respectively. All herbicide treatments reduced weed growth (dry-weight basis) and weeding times. Major weeds were dogfennel [Eupatorium capillifolium (Lam.) Small], southern crabgrass [Digitaria ciliaris (Retz.) Koeler], yellow woodsorrel (Oxalis stricta L.), tasselflower (Emilia spp.), and hairy crabweed [Fatoua villosa (Thumb.) Nakai]. Based on weed dry weights, overall weed control for the first 4 months was higher for diazopyr, thiazopyr, and prodiamine G than for the combination treatment. At 8 months, weed growth was similar for all herbicide treatments. The combination treatment was acutely phytotoxicity to more crops than the other treatments; however, phytotoxicity varied with crop, active ingredient, and formulation.
020 A Survey of Strawberry Inflorescence Injury Caused by Strawberry Bud Weevil, Anthonomus signatus
Authors: Handley David T. , Wheeler Andrew , Dill James F.
Published: February 2019

Three strawberry fields in Maine where surveyed to determine what level of blossom injury was caused by strawberry bud weevil; whether different orders of blossoms were effected differently; and whether injury was influenced by the location of the plants in the field. Three strawberry fields which had no insecticide applications where surveyed. A sample of 200 inflorescences where examined in four different locations in each field. The number of inflorescences in a field that had injury from strawberry bud weevil varied from 10% to 64%. Most flower clusters showing injury had one bud girdled, but many had two or more buds girdled. The tertiary and secondary order buds had the highest levels of injury, while the primary and quaternary buds had the lowest levels of injury. Location of the plants in the field did not show any obvious effects on injury levels.
021 Strawberry Fruit Phyllody Caused by Phytoplasmas
Authors: Jomantiene R. , Maas J.L. , Dally E.L. , Davis R.E.
Published: February 2019

Strawberry fruit phyllody, production of leaves and other vegetative organs from fruit tissue around achenes, has been ascribed to physiological causes due to temperature conditions during transplant cold storage, plant response to changing seasonal conditions at flower initiation time, and to phytoplasma infection. In examination of phylloid fruits from different strawberry clones and from different locations and sources, we found four distinct phytoplasmas associated with phyllody of strawberry fruit: strawberry multicipita (SM) phytoplasma (16S rRNA group VI, subgroup B), STRAWB2 phytoplasma (16S rRNA group I, subgroup K), clover yellow edge phytoplasma (16S rRNA group III, subgroup A), and a new group III phytoplasma. The SM and STRAWB2 phytoplasmas were detected in plants with phylloid fruit that also exhibited stunting and crown proliferation (SM phytoplasma) or stunting and leaf chlorosis (STRAWB2 phytoplasma). In no instances did we fail to detect phytoplasmas in phylloid fruit. To our knowledge, this is the first report to associate strawberry fruit phyllody with the presence of these phytoplasmas and to report that phytoplasmas other than those belonging to 16S rRNA group I (aster yellows group) can also be associated with strawberry fruit phyllody.
023 Field Evaluations of Meadowfoam Seedmeal to Control Clubroot Disease (Plasmodiophora brassicae) in Cruciferous Crops
Authors: Svenson Sven E. , McReynolds Robert B. , Deuel Wes A.
Published: February 2019

Field evaluation of meadowfoam (Limnanthes alba) seedmeal as a soil amendment to control clubroot caused by Plasmodiophora brassicae was conducted using cauliflower seedlings and seeded mustard grown in naturally infested soils. Ionic surfactant drench was applied as a comparative treatment. Meadowfoam seedmeal (MSM) incorporation at a rate of 15,000 kg·ha-1 resulted in greatest control of clubroot incidence and severity. This treatment also resulted in significantly greater fresh weight yield of cauliflower compared to controls and surfactant drench application. Some phytotoxicity symptoms were observed at high rate (30,000 kg·ha-1) of MSM treatment. MSM glucosinolate products may have an important role in regulating plant-pathogen interactions.
024 Evaluation of Reflective and Cover Crop Mulches in Fresh-market Tomato Production Systems
Authors: Mitchell Jeff , Summers Charlie , Stapleton Jim
Published: February 2019

Three systems for fresh-market tomato production (transplanting into reflective mulch, transplanting into a cover crop that had been chopped and killed, and standard transplanting into fallow beds) were evaluated in two field experiments in California's San Joaquin Valley in 1999. The first study was a spring tomato planting (April) and summer (July) harvest in which a mixture of rye, triticale, and vetch was used as the cover crop mulch. The second trial consisted of a summer tomato planting (July) and fall (September) harvst in which a sorghum/sudan hybrid was used as the mulch. In both experiments, tomato plants growing over the reflective mulches accumulated significantly more biomass than did plants growing in the other production systems. These larger, more-robust plants growing over reflective mulch also produced significantly higher yield. In the summer planting, there was almost no tomato biomass accumulation in the cover crop plots due to the fact that the sorghum-sudan hybrid we chose as the cover crop turned out to be allelopathic to tomatoes when shredded and used as a mulch.
027 Tomato Plant Size and Fruit Yield as Affected by the Date of Symptom Appearance of Tomato Spotted Wilt Virus
Authors: Diaz-Perez Juan C. , Bertrand D. , Giddings D.
Published: February 2019

Tomato spotted wilt virus (TSWV) can cause serious damage to tomato, pepper, lettuce, and other crops. The virus is transmitted by several species of thrips. The objective of this study was to determine the effect of the time (t, days after transplanting) when TSWV symptoms first appeared on tomato plant size and fruit yield. Tomato (`Florida-47') plants were drip-irrigated and planted over black plastic mulch. The experiment was carried out in Tifton, Ga., during Spring 1999. High populations of thrips were detected since early stages of plant development, which resulted in a high incidence of TSWV. Plant fresh weight was significantly higher (r2 = 0.632, n = 216) the later in plant development TSWV symptoms first appeared (i.e., with increasing t values). Total fruit production of individual plant linearly increased with increasing t values (r2 = 0.664, n = 216). As with total fruit production, fruit marketable yield was also higher with increasing t values; however, marketable yield was significantly reduced even when plants were infected later in the season (t > 55 days after transplanting). Our results suggest that it is important to keep tomato plants free from TSWV as long as possible. This applies to both developing and developed plants.
029 Synergism of Fumigant Combinations for Nutsedge Control
Authors: Hutchinson Chad , McGiffen Milt , Sims James , Becker J. Ole
Published: February 2019

As of 2005, methyl bromide will no longer be produced or imported for agricultural use in industrialized countries. The uncertain future of methyl bromide as a soil fumigant has stimulated research into the use of other soil fumigants for weed control. Laboratory experiments were conducted to determine the efficacy of methyl bromide (MB), methyl iodide (MI), propargyl bromide (PB), 1,3-dichloropropene (1,3-D), and metham sodium (MS) alone and in combination with chloropicrin (PIC) against Cyperus esculentus L (yellow nutsedge). The experimental design was a randomized complete block with three replications. All experiments were repeated. Tubers were imbibed for 24 h and mixed with soil adjusted to 14% moisture (w/w). Soil/tuber samples were fumigated for 48 h with MB, MI, 1,3-D, and PIC at 0.0, 3.1, 6.3, 12.5, 25, 50, 100, and 200 μm of active ingredient. Samples were fumigated with PB and MS at 0.0, 0.8, 1.6, 3.1, 6.3, 12.5, 25, and 50 μm of active ingredient. After fumigation and venting, each soil/tuber sample was wetted and placed in a Petri plate for 5 days. Shoot emergence was recorded. Additionally, to determine synergism response with PIC, 17% PIC was added to each fumigant/rate combination. Fumigation and data collection were performed as described above. Dose-response curves were constructed to determine the effective dose to control 50% of nutsedge emergence (ED50). PB and MS were the most efficacious fumigants with ED50's of 3.7 and 6.5 μm, respectively. EC50 values for all the fumigants were significantly lower than MB except for 1,3-D. All the fumigant-PIC combinations resulted in synergistic control of nutsedge.
033 Improved Seed and Embryo Development of Seedless Grapevine by Plant Growth Regulators
Authors: Iwanami Hiroshi , Hirakawa Nobuyuki , Yamane Hiroyasu , Sato Akihiko
Published: February 2019

Crosses between seedless cultivars had been conducted to produce seedless table grape efficiently by combining with ovule and embryo culture in Vitis vinifera L. But very few plants grew normally in this method. Four plant growth regulators (Cycocel, B-Nine, Uniconazole-P, Ethrel) were applied to shoots 4 weeks before anthesis to develop the seeds of two seedless cultivars `Flame seedless' and `A1706'. Correlation was significant in each cultivar between the shoot length at anthesis and the number of seed traces per berry in all combined treatments. Analysis of covariance revealed that the number of seed traces per berry was significantly higher when the shoots were applied with Uniconazole-P (240 ppm) than B-nine (2000 ppm), Cycocel (500 ppm) and Ethrel (400 ppm) in `Flame seedless' and Uniconazole-P and B-nine than Ethrel in `A1706'. Ovules of these two seedless cultivars crossed with seedless cultivar `Perlette' after the application of four plant growth regulators were cultured on half-strength MS medium with 10 μm IAA and the percentage of developed embryos in ovules was higher when the shoots were applied with Uniconazole-P and B-nine than Cycocel, Ethrel in `Flame seedless' and B-nine than others in `A1706'. These results indicate that the use of certain plant growth regulators promotes the embryo development.
034 Resistance to Root-knot Nematode in Vitis champinii
Authors: Cousins Peter , Walker M. Andrew
Published: February 2019

The grape Vitis champinii Planchon is one source of nematode resistance in grape rootstocks. Several selections valued for their resistance to the root-knot nematode (Meloidogyne incognita), a serious pest of grape production, are used as rootstocks and in rootstock variety development. However, V. champinii-based rootstock varieties are faulted for their excess vigor and susceptibility to other root pests. Root-knot nematode populations with the ability to damage important V. champinii-based rootstocks have been identified and may become more common. Other V. champinii accessions might be sources of nematode resistance genes with different specificities or might have more suitable horticultural characteristics than V. champinii varieties in commercial use. Nine V. champinii accessions from the National Clonal Germplasm Repository, Davis, Calif., and a V. champinii rootstock variety were screened for resistance to M. incognita. Resistance was assessed by counting eggs produced per root system. Eight of ten V. champinii accessions did not support nematode reproduction. Susceptible accessions supported lower nematode reproduction than susceptible V. vinifera control varieties. Progeny testing from crosses of resistant and susceptible accessions suggests that a dominant and a recessive gene may condition root-knot nematode resistance.
037 In Vitro Plant Regeneration for `Marion' Blackberry
Authors: Meng Rengong , Chen Tony H.H. , Finn Chad E.
Published: February 2019

`Marion' is the most important blackberry cultivar in the world, primarily due to its outstanding processing characteristics. Ideally, `Marion' could be enhanced via transformation while maintaining its fruit quality. As a successful in vitro regeneration is the prerequisite for genetic transformation, a series of experiments were conducted to optimize the conditions for in vitro regeneration for `Marion' blackberry. Parameters studied included types (three cytokinins: BA, kinetin, and zeatin; four auxins: IBA, IAA, NAA, and 2,4-D) and concentrations of plant growth regulators, explants (leaf and petiole), medium formulations (MS, WPM, and BMM), and the duration of TDZ pretreatment (3 to 6 weeks) of in vitro-grown stock plants. The highest shoot regeneration rate (65.7%) and highest number of shoots (5.1 shoots/explant) were obtained under the following conditions: stock plants were pretreated with TDZ (1 mm) for 3 weeks, followed by leaf explants dark pretreatment for 1 week on the regeneration medium (WPM with 5 mM BA and 0. 5 mm IBA). After dark treatment, regeneration plates were placed under 16-h photoperiod at light intensity of ≈50 μmol·m-2·s-1 at 23 + 2 °C for 4 weeks.
039 Hardy Actinidia Genetic Resources at the Corvallis Repository
Authors: Hummer Kim E.
Published: February 2019

In 1999, the National Clonal Germplasm Repository at Corvallis, Ore., was assigned to preserve the hardy Actinidia Lindl. resources for the U.S. Dept. of Agriculture, Agricultural Research Service, National Plant Germplasm System. The fuzzy kiwifruit [A. deliciosa (A. Chev) C. F. Liang et A. R. Furguson] and other less cold-hardy Actinidia species, remain at the Davis Repository. The hardy Actinidia, commonly called Chinese gooseberries or hardy kiwifruit, encompass two taxonomic sections, Leiocarpae and Maculatae, and include about 13 described species. These perennial vines are natives of Asia and have been developed and cultivated in Lushan, Wuhan, and Guilin, China; Motueka, New Zealand; Kagawa Prefecture, Japan; Vladivostok, Russia; and California, Maryland, Michigan, Minnesota, New Hampshire, and New York in the United States. Thus far, the Corvallis Repository has established representatives of six species, A. arguta (Siebold & Zucc.) Planch. Ex Miq., A. callosa Lindl., A. kolomikta (Maxim.&Rupr.) Maxim, A. melanandra Franch., A. polygama (Siebold & Zucc.) Maxim., A. purpurea Rehder and 60 cultivars. These clones will be preserved as potted plants under screen. They will also be fruited and evaluated as trellised plants in the field. The repository plans to expand the species diversity of the collections. Plant requests for dormant scionwood or spring softwood cuttings are available by contacting the Corvallis Repository Curator.
044 Screening for Resistance to Azalea Lace Bug among Deciduous Azalea Progeny from a Cross between a Highly Susceptible to a Highly Resistant Genotype
Authors: Robacker Carol D. , Braman S.K.
Published: February 2019

Azalea lace bug, Stephanitis pyrioides (Scott), is a major pest on azalea. Adults and nymphs feed and oviposit on the underside of the leaves, causing a stippled appearance when viewed from above. Previous field and laboratory screenings of 17 taxa of deciduous azalea, including representatives of 11 species, have identified a range of resistance to lace bug. One of the most resistant plants observed was of the species R. canescens. The interveinal region on the underside of the leaves of this plant is highly pubescent. This plant was crossed to a susceptible plant of R. viscosum (formerly R. serrulatum), which was glabrous on the lower leaf surface. The resulting seeds were planted in 1996, and the seedlings were transplanted to the field in 1998. In Sept. 1999, a laboratory bioassay was conducted to determine the resistance levels of these progeny. Five cuttings, each with two leaves, were collected from each plant, including the parental genotypes. Two female lace bugs were transferred onto the leaves of each cutting and the leaves were enclosed in a plastic cup with mesh for ventilation. After 5 days, the number of live bugs and number of eggs per cutting were counted. The percent damage from feeding was estimated. To determine whether pubescence was correlated with lace bug resistance, two terminal leaves were collected from each plant, and interveinal leaf hair density was calculated. Results from the laboratory bioassays revealed a high degree of susceptiblity to lace bug among these seedlings. Most of the progeny were pubescent, indicating no relationship between leaf hair density and resistance.
045 `African Beauty': A New Ornamental Camphor Basil
Authors: Morales Mario R. , Simon James E.
Published: February 2019

`African Beauty', a new ornamental camphor basil cultivar, was developed through three cycles of selfing and selection from USDA accession PI 500942, originally collected in Zambia, Africa. `African Beauty' was field-evaluated and compared with PI 500942 (the original population), PI 500954 (another accession from Zambia), a camphor cultivar from Companion Plants, and three other related lines in 1997 and 1998. Most commercial camphor basils are tall (50 to 60 cm), late-flowering, and unattractive. Our goal was to develop a new cultivar that had a short stature (≈40 cm), an early flowering, and an attractive appearance. The outcome was `African Beauty', which has the following characteristics: plant height: 30 to 35 cm, plant spread: 50 to 55 cm, leaf length: 6.3 to 6.7 cm, days to flower: 76 days, inflorescence length: 25 cm, essential oil yield: 3 mL/100 g dw. The essential oil of `African Beauty' is also highly aromatic, with 72% camphor, 12% camphene, and 9% limonene. The plant is a fast-growing, semicompact aromatic plant that produces small leaves and large quantities of long and slender inflorescences that, when fully developed, curve at the tip like the tail of a cat. Blooming usually lasts from 20 to 25 days, when the plant looks most beautiful. `African Beauty' is an attractive ornamental that would be excellent as a garden border plant, or as an indoor potted plant.
046 Database Management of the Breeding Program at the USDA-ARS Sugarcane Research Station
Authors: Stafne E.T. , Brown J.S.
Published: February 2019

A computerized relational database is an efficient and powerful way to store, retrieve, query, and manipulate data. Databases have been prevalent in the scientific community for several years but, recently, have become more immediately available. Personal computers and local area networks (LAN) have revolutionized the accessibility of shared data. At the USDA-ARS Sugarcane Field Station, a database has been created to streamline the entry and recovery of data for the breeding program using Microsoft (MS) Access 2000, a readily available and inexpensive product, which makes it highly adaptable to a variety of breeding programs. Data collection from the sugarcane breeding program has previously consisted of field books and separate computer files. This method of documentation can lead to errors and lost data, therefore a multi-user database was needed to avoid continued problems in data handling. Data entry is performed though a series of self-explanatory forms. Once entered, data can be accessed through the LAN and easily sorted or grouped as desired or queried for items of interest. Reports can then be output as a means of storing important hard copy records. Data from stage I and stage II (the first two clonally propagated selection stages) of the breeding program have currently been included in the database, as well as the seedling stage (true seed planting). Future plans are to incorporate data from stage III and IV (the final two clonally propagated selection stages). The database also handles the Canal Point breeding collection inventory, crossing information, seed (fuzz) inventory, and pedigree tracking. This type of database has widely applicable properties that can be implemented to handle data for any crop, either agronomic or horticultural.
047 Response to Selection for Anthocyanin Pigment Concentration in Wisconsin Fast Plant Populations by University of Wisconsin Students
Authors: Goldman I.L.
Published: February 2019

Wisconsin Fast Plants are rapid-cycling versions of various Brassica species amenable to a variety of genetic studies due to their short life cycle and ease of handling. I have recently developed a model system using Brassica rapa L. Fast Plants for teaching the cyclical selection process known as recurrent selection in the context of a course on plant breeding. The system allows for up to three cycles of recurrent selection during a 15-week semester and enables students to gain experience in planting, selection, pollination, and seed harvest during each cycle. Fourteen cycles of replicated, recurrent mass selection for high (H) and low (L) levels of anthocyanin pigment expression in hypocotyl tissue were practiced by students in Horticulture 502 during a period of four semesters. In addition to bi-directional selection; replicated unselected (D) control populations were maintained forcomparative purposes. Over 14 cycles, highly significant gains and losses in hypocotyl pigment production were realized for H and L populations, respectively. Plants in D populations showed no directional response to random selection and therefore did not exhibit genetic drift. Plants in H populations exhibited production of anthocyanin pigment in organs other than hypocotyls, suggesting selection goals could be modified to include pigmentation of specific organs or whole plants. Results from this selection program suggest significant gains from recurrent selection can be visualized through student-based selection activities in the classroom.
056 Genetic Evaluation of Onion-induced Antiplatelet Activity and Soluble Solids of F3 Families Derived From a Mild by Pungent Onion (Allium cepa) Cross
Authors: Orvis Kathryn S. , Goldman Irwin L.
Published: February 2019

Heart attack and stroke, a leading cause of death in the United States, have been associated with blood platelet aggregation. Onion extract inhibits blood platelet aggregation both in vitro and in vivo. Current trends toward natural foods and health remedies may point to the importance of onion-induced antiplatelet activity (OIAA). The genetic control of OIAA has yet to be revealed. One-hundred-eighty-three F3 families were derived from a long-day mild inbred line crossed to a long-day pungent inbred line that differ by for OIAA by 67%. Families were grown in a RCB design with two replications in muck soil (Randolph, Wis.) in 1997. Extracts were made from crushing bulb tissue in a mechanical juicer. F3 families were evaluated for OIAA and soluble solids (SS). OIAA was measured by electrical impedance aggregometry using two human blood donors. Endpoint (ohms) and slope of the aggregation curve were recorded. SS were measured by refractometry. F3 families were significantly different for OIAA and SS (P < 0.0001) in the ANOVA. A strong positive correlation of 0.96 was revealed for slope of curve and endpoint across families, replications, and blood donors. This correlation has not been previously reported for onion and suggests that for these families, descriptions of OIAA based on either rate of aggregation or endpoint are functionally equivalent. Both SS and OIAA exhibit transgressive segregation in this group of F3 families. Twenty percent exhibit OIAA stronger than the pungent parent and 5% were less than the mild parent. The family with the highest OIAA was 4-fold higher than the pungent parent of the cross, which could be useful in future onion breeding efforts. In addition, transgressive segregation in these families aids in QTL investigations for OIAA, SS and other economically important traits.
057 Hybrid Performance of Male-sterile and Pollinator Inbred Onion Lines
Authors: Cramer Christopher S. , Mendoza Jose L. , Corgan Joe N.
Published: February 2019

Current emphasis of onion breeding programs has been to develop male-sterile, maintainer, and pollinator inbred lines for the production of hybrid cultivars. Five short-day, male-sterile inbred lines from the New Mexico State Univ. Onion Breeding Program were crossed to four short-day, pollinator inbred lines in all possible combinations. In addition, six intermediate-day male-sterile inbred lines were crossed with seven intermediate-day, pollinator inbred lines in all possible combinations. The resulting hybrid lines from all crosses were evaluated for maturity, bolting resistance, pink root resistance, Fusarium basal rot resistance, percentage of marketable bulbs, marketable yield, average bulb weight, and percentage of bulbs with single centers. The average performance among male-sterile and among pollinator lines within each group was determined by averaging over hybrid lines that pertained to the respective male-sterile or pollinator line. Among the short-day inbred lines, NMSU 97-28-2 and NMSU 97-109-2 as female parents produced the best hybrid lines, while NMSU 96-17-1 and NMSU 96-51-1 as male parents produced the best hybrid lines. The best hybrid combinations among the short-day parents were NMSU 97-28-2 × 96-17-1 and 97-46-2 × 96-51-1. Among the intermediate-day inbred lines, NMSU 96-196-2 and 96-300-2 as female parents produced the best hybrid lines, while NMSU 96-280-1, NMSU 96-274-1 and 96-395-1 as male parents produced the best hybrid lines. Some of the best intermediate-day hybrid combinations included NMSU 96-300-2 × 96-335-1 and NMSU 96-300-2 × 96-274-1.
058 Variation in β-carotene and Total Carotenoid Content in Capsicum Germplasm
Authors: Wall Marisa , Waddell Cynthia , Bosland Paul , Walker Stephanie
Published: February 2019

The β-carotene and total carotenoid content of different Capsicum fruit types and species were analyzed using HPLC. This information is useful for breeding high carotenoid chiles (New Mexican type) for the food industry, and also provides nutritional data for the range of fruit types within the Capsicum genus. Fresh fruit from 25 accessions and dried fruit from 39 accessions were evaluated in 1996 and 1997. β-carotene levels varied from 0 to 16.6 mg/100 g fresh weight, and carotenoid levels were from 0.1 to 89.6 mg/100 g in red ripe fruit in 1996. The range of values for β-carotene was similar in 1997, but a wider range in total carotenoids (0.4 to 117.3 mg/100 g fresh weight) was observed. Fresh fruit (100 g) of the cultivars `Greenleaf Tabasco', `Pulla', `Guajillo', `NuMex Conquistador', `Ring-O-Fire', and `Thai Dragon' contained greater amounts of β-carotene than the RDA for vitamin A for the average adult. For dried Capsicum entries, New Mexican, aji, pasilla, ancho, and guajillo types had the highest levels of β-carotene. In 1996, β-carotene levels among the dried Capsicum germplasm ranged from 0 to 739.2 μg/g dry weight, and carotenoid levels were from 21.3 to 6,225.9 μg/g. Values were higher in 1997, and ranged from 23.7 to 1,198.1 μg/g dry weight for β-carotene and from 76.9 to 10,120.6 μg/g for total carotenoids. A pasilla type (C. annuum) had the highest total carotenoid content among the dried entries in both years.
059 Molecular Markers Linked to the Ur-6 Gene Controlling Specific Rust Resistance in Common Bean
Authors: Park Soon O. , Coyne Dermot P. , Steadman James R.
Published: February 2019

Bean rust, caused by Uromyces appendiculatus, is an important disease of common bean (Phaseolus vulgaris L.). The objective was to identify RAPD markers linked to the gene (Ur-6) for specific resistance to rust race 51 using bulked segregant analysis in an F2 segregating population from the common bean cross pinto `Olathe' (resistant to rust) × great northern Nebraska #1 selection 27 (susceptible to rust). A single dominant gene controlling specific resistance to race 51 was hypothesized based on F2 segregation, and then was confirmed in the F3 generation. A good fit to a 3:1 ratio for band presence to band absence for each of three markers was observed in 100 F2 plants. Three RAPD markers were detected in a coupling phase linkage with the Ur-6 gene. Coupling-phase RAPD marker OAB14.600 was the most closely linked to the Ur-6 gene at a distance of 3.5 cM among these markers. No RAPD markers were identified in a repulsion phase linkage with the Ur-6 gene. The RAPD markers linked to the gene for specific rust resistance of Middle American origin detected here, along with other independent rust resistance genes from other germplasm, could be utilized to pyramid multiple genes into a bean cultivar for more durable rust resistance.
071 Partial Sequence of Ethylene Receptor Genes in Carnations with Different Ethylene Sensitivity
Authors: Nagata Masayasu , Tanikawa Natsu , Onozaki Takashi
Published: February 2019

The plant hormone ethylene plays an important role in the senescence process of carnation flowers. Recently, various genes that concern ethylene responses have been cloned from many sources of plants. Our main aim is to compare the sequences of ethylene receptor genes among carnations with different ethylene sensitivities. Four carnations, `White Sim' (ethylene sensitive control), `Chinera' (lower ethylene sensitivity), 64-13 and 64-54 were used. The carnations temporarily named as 64-13 and 64-54 are our breeding lines with less ethylene sensitivity, thus better flower retention. Total RNA was extracted using SDS-phenol method. Putative ethylene receptor genes were cloned by RT-PCR using degenerate primers that correspond to the highly conserved regions of ETR1 and ERS genes. Two kinds of DNA fragments, ≈1 kb in the length encoding putative ethylene receptor genes were cloned from all samples. An ERS-type gene was cloned that is identical to the gene, known as DC-ERS2 (Accession No. AF034770). Another was ETR1-type gene, which has not been reported in carnations yet. That was 91% identical to the ETR1 gene from melon or apple at the translated amino acid level. The deduced amino acid sequences of ERS-type genes among four samples were almost the same. However there were five mutations in `Chinera', one mutation in 64-13 and two mutations in 64-54, compared to `White Sim' at the translated amino acid level. As they located rather conserved regions of the gene, it is expected to affect the less ethylene sensitivity of the carnations.
072 New Pepper Germplasm for Ornamental and Ornamental/Culinary Applications
Authors: Stommel John R. , Griesbach Robert J.
Published: February 2019

Ornamental peppers are a novel and growing segment of the ornamentals industry. Currently available varieties are utilized as pot plants and in bedding plant applications. Utilizing unimproved populations developed from initial crosses with Indian Capsicum land races, germplasm lines with unique gene combinations for multiple fruiting, fruit orientation, leaf pigmentation and leaf variegation were developed and released by USDA-ARS. Via introgression of diverse Capsicum species accessions and heirloom varieties into these populations, more recent efforts seek to exploit abundant genetic variation for fruit shape, size, color and pungency, foliar attributes, and plant growth habit to develop new pepper germplasm for ornamental and dual ornamental/culinary applications. Fruit pungency of selected material may range from mild to extremely pungent. Fruit shape may be round, conical, or lobed. Whereas small fruit size is generally well suited for ornamental applications, ornamental/culinary types exploit larger upright conical or small bell-shaped fruit. Plant foliage may be uniformly green in color, exhibit varying degrees of anthocyanin accumulation, or display variegation. Inheritance of selected attributes, potential barriers to development of select recombinants, and examples of representative advanced selections in the breeding program will be presented.
073 Stomatal Density as a Correlated Trait to Postharvest Longevity in Antirrhinum majus L. (Snapdragon)
Authors: Martin William J. , Stimart Dennis P.
Published: February 2019

Stomatal density is being investigated as a highly correlated trait to postharvest longevity (PHL) and subsequently may be used for selection in early generations of breeding germplasm. To this end, leaf imprints were created from Antirrhinum majus L. (snapdragon) P1, P2, F1, BC1 (F1×P1), BC2 (F1×P2), F2, and F3 plants and evaluated for stomatal densities. Cut flowers of P1, P2, F1, BC1 (F1×P1), BC2 (F1×P2), and F3 were harvested after the first five flowers opened and evaluated for PHL. Additionally, cut flowers from these lines were evaluated for leaf surface area. Populations for evaluation were grown in the greenhouse in winter and spring 1999-2000 in a randomized complete-block design according to standard forcing procedures. Twenty-five cut flowering stems of each genotype were held in the laboratory in deionized water under continuous fluorescent lighting at 22 °C for PHL assessment. The end of PHL was defined as 50% of the flowers drying, browning, or wilting. Data will be presented on the correlation between stomatal density and PHL.
077 In Vitro Growth of Immature Peach [Prunus persica (L.) Batsch] Embryos Related to Carbohydrate Source
Authors: Sinclair Jonathan W. , Byrne David H.
Published: February 2019

Carbohydrate energy source of various tissue culture media has an effect on growth and survival of the explants. Sucrose is the standard carbohydrate used in most tissue culture systems. The objective of the study was to determine the effect of five carbohydrate sources (fructose, glucose, maltose, sorbitol, and sucrose) at two levels (2% and 3%) on germination, growth, and survival of immature peach embryos (9.7 to 14.7mm) in vitro. Five cultivars were used. Overall, fructose, maltose, and sucrose each stimulated germination and growth as the primary carbohydrate energy source of peach embryo culture to the same degree; glucose and sorbitol were inferior. However, fructose was superior to sucrose in one cultivar. In general, sugar level did not affect survival, although cultivars did vary somewhat. Survival was found to be highly dependent upon embryo maturity.
082 Identification and Partial Characterization of Seasonally Regulated Proteins in Apple Bark Tissues
Authors: Wisniewski Michael , Fuchigami Les
Published: February 2019

During autumnal leaf senescence, leaf nitrogen is translocated to bark and root tissues for storage. By definition, proteins that accumulate in large amounts in winter and are absent in summer are called storage proteins. These storage proteins are believed to play an important role in spring growth and helping trees to tolerate and/or recover from both abiotic and biotic stress. Little knowledge exists regarding storage proteins in apple, their physiological function, or how management practices impact them. Our objectives in this research was to characterize seasonally regulated proteins in apple, develop knowledge about their physiological function, and determine how they are affected by management practices. Results of the first-year studies have identified four major proteins that exhibit a seasonal pattern of accumulation in bark tissues of apple. One of these is a pathogenesis-related protein, meaning that it plays a role in disease resistance. Another of these proteins is a stress-related protein important in the use of carbohydrates under stress conditions. A third protein is a vegetative storage protein serving as a reserve for nitrogen. The last protein has not been completely identified. Greatest seasonal fluctuation of these proteins occurred in current season and 1-year-old bark tissues. Experimental studies that achieved varying levels of nitrogen in shoot tissues of young Fuji apple trees were examined for the effect on the accumulation of these proteins. Results indicated that despite a significant increase in total nitrogen, increases in the accumulation of these proteins were only slight. Instead, it appears that most of the nitrogen was present as free amino acids rather than stable proteins. These data indicate that more knowledge is required to determine the benefits and feasibility of elevating the levels of specific proteins in dormant apple trees or trying to manipulate the type of amino acids that accumulate.
083 Is HMGR the Key Regulator of α-Farnesene Biosynthesis of Apple?
Authors: Rupasinghe H.P.V. , Almquist K.C. , Paliyath G. , Murr D.P.
Published: February 2019

We tested the hypothesis that conversion of 3-hydroxy-3-methylglutaryl co-enzyme A (HMG CoA) to mevalonate (MVA) catalyzed by HMG CoA reductase (HMGR) is the rate limiting step for α-farnesene biosynthesis of apples. In higher plants, isopentenyl pyrophosphate (IPP) is derived via two pathways: 1) the classical mevalonate pathway, and 2) the novel glyceraldehyde-3-phosphate (GAP)/pyruvate pathway independent of HMGR action. When apple skin discs were incubated with MVA, or GAP and pyruvate, MVA increased α-farnesene levels in the skin but not GAP and pyruvate. Treating apple fruits with Lovastatin (1000 ppm), a competitive inhibitor of HMGR, inhibited α-farnesene accumulation in the skin by 20% to 50% during storage. Content of α-farnesene in the skin increased during the first 2 to 4 months in storage, and then decreased. In contrast, HMGR activity, as determined by the conversion of [4-3H]HMG CoA to MVA in the total membrane and soluble fraction, was the highest at the time of harvest and gradually decreased during 5 months of storage in air at 0 °C. The potent ethylene action inhibitor 1-MCP inhibited ethylene production and α-farnesene evolution by 99% and 97%, respectively. The effect of 1-MCP on in vitro activity of HMGR was marginal (≈30% inhibition). 1-MCP inhibited respiratory CO2 evolution by 50%, which suggests also that inhibition by 1-MCP of α-farnesene synthesis in apple could be regulated by the acetyl CoA pool. In plants, HMGR is encoded by a small gene family and differentially expressed. As the first step of studying the molecular mechanism of HMGR regulation, we have isolated a 444-bp fragment of apple hmgr gene using apple skin mRNA and degenerate oligonucleotides designed against conserved regions of plant hmgr genes.