bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite element method analysis of occlusal splint therapy in patients with bruxism
Authors: Gholampour Seifollah , Shariati Azadeh
Published: June 2019

Background: Bruxism is the most important risk factor for temporomandibular joint (TMJ) disorders. Methods: Three-dimensional models of maxilla and mandible and teeth of 37 patients and 36 normal subjects were made using in-vivo image data. The maximum values of stress and deformation were calculated in 21 patients six months after using splint and compared with the initial conditions. Results: The maximum stresses in jaw bone and head of mandible in patients were 4.4 and 4.1 times higher than those in normal subjects, respectively. Similar values for deformation were 5.8 and 4.9, respectively. Six months after splint application, the maximum stress in the jaw bone and head of mandible decreased by up to 71.0% and 72.8%, respectively. Similar values for the maximum deformation were 80.7% and 78.7%, respectively. With occlusal splint therapy, the approximation of the maximum deformation to the relevant values in normal subjects was about 2.6 times the approximation of maximum stress to the relevant values in normal subjects. The maximum stress and maximum deformation occurred in all cases in the head of the mandible and the splint had the highest effectiveness in jaw bone adjacent to the molar teeth. Conclusions: Splint acts as a stress relaxer and dissipates the extra generated stresses and especially the deformation and deviations of TMJ due to bruxism. The splint also makes the bilateral and simultaneous loading possible and helps with the treatment of this disorder through regulation of bruxism by creating a biomechanical equilibrium between the physiological loading and the generated stress.
Larva of greater wax moth Galleria mellonella is a suitable alternative host for the fish pathogen Francisella noatunensis subsp. orientalis
Authors: Djainal Winarti Achmad Sarmin , Shahin Khalid , Adams Alexandra , Desbois Andrew
Published: June 2019

Background

Francisella noatunensis subsp. orientalis (Fno) is the etiological agent of francisellosis in cultured warm water fish, such as tilapia. Antibiotics are administered to treat the disease but a better understanding of Fno infection biology will inform improved treatment and prevention measures. However, studies with native hosts are costly and considerable benefits would derive from access to a practical alternative host. Here, larvae of Galleria mellonella were assessed for suitability to study Fno virulence.

Results

Larvae were killed by Fno in a dose-dependent manner but the insects could be rescued from lethal doses of bacteria by antibiotic therapy. Infection progression was assessed by histopathology (haematoxylin and eosin staining, Gram Twort and immunohistochemistry) and enumeration of bacteria recovered from the larval haemolymph on selective agar. Fno was phagocytosed and could survive intracellularly, which is consistent with observations in fish. Virulence of five Fno isolates showed strong agreement between G. mellonella and red Nile tilapia hosts.

Conclusions

This study shows that an alternative host, G. mellonella, can be applied to understand Fno infections, which will assist efforts to identify solutions to piscine francisellosis thus securing the livelihoods of tilapia farmers worldwide and ensuring the production of this important food source.
Renewable Biomethane From Land and Ocean Energy Crops and Organic Wastes
Authors: Chynoweth David P.
Published: June 2019

Production of methane via anaerobic digestion of energy crops and organic wastes would benefit society by providing a clean fuel from renewable feedstocks. This could replace fossil fuel-derived energy and reduce its environmental impacts, including global warming and acid rain. Although biomass energy is more costly than fossil fuel-derived energy, trends to limit carbon dioxide and other emissions through regulations, carbon taxes, and subsidies of biomass energy would make it cost competitive. Methane derived from anaerobic digestion is competitive in efficiencies and costs with other biomass energy forms including heat, synthesis gases, and ethanol. The objective of this paper is to review the results and conclusions of research on biomass energy conducted under the sponsorship of the gas industry with periodic co-funding from other agencies. The scope of this program was to determine the technical and economic feasibility of production of substitute natural gas (SNG) from marine and terrestrial biomass and organic wastes using anaerobic digestion as a conversion process. This work began in 1968 and continued until about 1990, ending as a result of low energy prices in the U.S. and reduced emphasis on renewable energy. For each of these feedstock categories, growth or collection (in the case of wastes), harvesting, conversion by anaerobic digestion, and systems and economic analysis were addressed. More recently the potential use of anaerobic digestion for stabilization and recovery of nutrients from solid wastes during space missions was studied with funding from NASA. The application of this process for that function as well as treatment of wastewater and waste gases generated during space missions is addressed.
Realizing Value from Central Asian Allium Germplasm Collections
Authors: Simon Philipp W.
Published: June 2019

Central Asia is the center of origin for many Allium species and a rich genetic source of wild relatives of onion and garlic. For this reason germplasm collections of cultivated Alliums have targeted the acquisition of seed and bulb samples from this region, and several plant expeditions from Asia, Europe, and North America have collected Allium germplasm in Central Asia. Central Asian Allium germplasm has been valuable both as raw materials for scientific research leading to published data, and as starting materials for genetic improvement of the crop. Utilizing this germplasm it has been possible to improve garlic so it can be bred like other seed-propagated crops. Several interspecific crosses have been made between onion and other Central Asian wild relatives and these crosses have yielded useful traits for onion improvement. Allium germplasm from this region has also been important in elucidating the systematics and origins of diversity in onion and garlic. By any of these measures, Central Asian Allium collections have been valuable. Challenges and successes in collecting, maintaining, evaluating, and using these collections remain.
Applicability of Leaf Morphology and Intersimple Sequence Repeat Markers in Classification of Tree Peony (Paeoniaceae) Cultivars
Authors: Suo Zhi-li , Li Wen-ying , Yao Juan , Zhang Hui-jin , Zhang Zhi-ming , Zhao Di-xuan
Published: June 2019

Tree peony cultivars are usually classified according to flower characteristics (flower form and flower color) which are commonly affected by environmental influences and developmental levels. Judgment of flower forms may also depend on the observer. Precise and rapid cultivar identification methods are also required to manage cultivar collections as well as tree peony breeding programs. The objective of this paper is to analyze the discriminatory ability of leaf morphology and Intersimple sequence repeat (ISSR) marker systems for tree peony cultivars. As a result, although there exist large variations of leaf morphology of tree peony cultivars, the morphological characteristics of biternately compound leaves 3, 4, and 5 from the base of a shoot at the middle part of a plant are relatively stable with smaller variations within cultivars (2.7% to 27.1%, 16.8% on average) and with larger differentiations among cultivars (72.9% to 97.3%, 83.2% on average). Statistical and principal components analyses indicate that 12 leaf morphological characteristics are valuable for cultivar classification. ISSR markers present a precisely discriminatory power in tree peony cultivar classification without environmental influences. The cultivars with multiple flower forms, which makes it difficult to make judgment by means of a flower-form-based classification system, have been significantly characterized using leaf morphology or ISSR markers.
Variability in the Relationship between Frost Temperature and Injury Level for Some Cultivated Prunus Species
Authors: Miranda Carlos , Santesteban Luis G. , Royo José B.
Published: June 2019

The influence of the species in spring frost sensibility was determined for the Prunus species peach (P. persica (L.) Batsch), sweet cherry (P. avium L.), almond (P. dulcis (Mill.) Webb/P. amygdalus Batsch), japanese plum (P. salicina Lindl.), and blackthorn (P. spinosa L.). The confidence intervals for lethal temperatures of 10% (LT10) and 90% (LT90) bud injury were also determined. In 2000 and 2001, seven frost treatments were made for each one of the phenological stages comprised between B (first swell) and I (jacket split) in two cultivars per each species. The relationships between frost temperature and the proportion of frost damaged buds for each cultivar, year, and phenological stage were adjusted to linear regression models. The 95% confidence intervals were also calculated. The spring frost hardiness order of the species, from the least to most hardy, was as follows: sweet cherry, almond, peach, japanese plum, and blackthorn. Despite the highly homogeneous nature of the frost and bud characteristics, the temperature range for a given injury degree was quite broad, since the confidence interval's breadth for LT10 was as high as about 3 °C and as high as about 6 °C for LT90. Consequently, when critical temperatures are used in making decisions as to when to begin active frost protection, a prudent measure would be to take the temperature references from the upper limits in the confidence intervals.
Development of a Nutrient Film Technique Culture System for Arbuscular Mycorrhizal Plants
Authors: Lee Yun-Jeong , George Eckhard
Published: June 2019

A nutrient film technique (NFT) culture system was developed to allow nursery production of arbuscular mycorrhizal horticultural crops. This would benefit horticultural production and allow for uncomplicated production of mycorrhizal hyphae. Roots of lettuce (Lactuca sativa var. capitata) plants were highly colonized by the arbuscular mycorrhizal fungus, Glomus mosseae (BEG 107) after 4 weeks in the NFT system, following an initial phase of five weeks in inoculated in Perlite substrate. In the NFT system, a thin layer of glass beads was used to provide solid support for plant and fungus growth and nutrient solution was supplied intermittently (15 min, six times per day). A modified nutrient solution (80 μm P) was used and was replaced with fresh solution every 3 days. A significantly higher dry weight was found for the mycorrhizal versus the nonmycorrhizal lettuce plants in Perlite during the precolonization period. The root colonization rate was also high at rates up to 80 μm P supply. On the NFT system, growth differences between mycorrhizal and nonmycorrhizal plants were less than in Perlite. However, root colonization rate was not reduced during the NFT culture period. In this system, high amounts of fungal biomass were produced. This would allow the determination of metal and other nutrient concentrations in fungal hyphae. Furthermore, we found large amounts of external fungal hyphae surrounding the root surface. As much as 130 mg fungal biomass were collected per culture plate (three plants). Therefore, we suggest that this modified NFT culture system would be suitable for fungal biomass production on a large scale with a view to additional aeration by intermittent nutrient supply, optimum P supply, and a use of glass beads as support materials. Furthermore, bulk inoculum composition with a mixture of spores, colonized roots, and hyphae grown in soilless media by the modified NFT system might be a useful way to mass-produce mycorrhizal crops and inoculum for commercial horticultural purposes.
Effects of Apogee on Growth and Whole-canopy Photosynthesis in Spur `Delicious' Apple Trees
Authors: Glenn D. Michael , Miller Stephen S.
Published: June 2019

This study examines the effect of multiple spray applications of Apogee on shoot growth and whole-canopy photosynthesis (WCPn) rate in young, bearing apple trees. Apogee increased fruit numbers and reduced shoot growth and inconsistently reduced leaf area but the reduction in photosynthetic area did not result in reduced WCPn or a detrimental effect on the fruit number:fruit size relationship. Since WCPn was not affected when leaf area was reduced by Apogee treatment, it suggests a greater photosynthetic efficiency of leaves on Apogee treated trees due to reduced shading. The use of Apogee for canopy management may produce a side-effect of increasing fruit set, which may be managed through a crop thinning program.
Greenhouse Seed Production of Two Dwarf Green Bean Cultivars in Relation to the Duration of Irrigation
Authors: Khah Ebrahim M. , Akoumianakis Konstantinos A. , Passam Harold C.
Published: June 2019

As good quality irrigation water becomes increasingly scarce in the Mediterranean region, especially in coastal areas where greenhouses are located, methods of economizing water consumption are essential. Therefore, the effect of the duration of irrigation on the quality and yield of seed of two cultivars of dwarf green bean (`Larma' and `Montano', Phaseolus vulgaris L.) was studied during fall and spring in Greece. Seeds were sown on 11 Sept. 2000 (fall crop) and 23 Feb. 2001 (spring crop) in peat compost and when the plants had two expanded leaves (11 and 20 days after sowing, respectively), they were transplanted to the soil of an unheated, plastic-covered greenhouse. The following irrigation treatments were applied: 1) irrigation for the entire duration (control), 2) irrigation until the first pods were dry, 3) irrigation until ≈50% of the pods had filled, and 4) irrigation till flowering. Fall cultivation was not suitable for seed production due to low yield and reduced seed quality. By contrast, the spring crop had a higher yield, seed size and good germination. Stopping irrigation of the spring crop at the drying of the first pods achieved an ≈20% saving in water without significantly affecting seed yield or quality. Earlier discontinuation of irrigation to achieve greater savings of water caused a reduction in yield, but did not affect seed quality.
Seeding of Creeping Bluegrass into Existing Golf Course Putting Greens
Authors: Miltner Eric D. , Stahnke Gwen K. , Rinehart Geoffrey J. , Backman Paul A.
Published: June 2019

The recent release of `True-Putt' (previously `DW-184') creeping bluegrass [Poa annua L. f. reptans (Hauskins) T. Koyama] gives turfgrass managers a new option for seeding into annual bluegrass (Poa annua L.) greens. Because little is known about the culture and management of this newly available seeded cultivar, effective methods for seedling establishment into existing turfgrass canopies, both living and dead, were studied. Four surface cultivation treatments were compared for seedbed preparation before seeding into an existing turfgrass canopy. When seeding into dead turf, two passes with vertical mowing units were more effective than hollow-tine cultivation (HTC), solid-tine cultivation (STC), one pass with the vertical mower plus STC, and the uncultivated control during the first year. Differences were not significant during the second year, most likely because of shallower depth of the vertical mower. Plots averaged about 75% cover by 4 weeks after planting during both years, illustrating the rapid establishment potential for `True-Putt'. After seeding into a live turf canopy, seedlings were indistinguishable from the existing turf, making it impossible to evaluate establishment success.
Responses of Creeping Bentgrass to Salinity and Mowing Management: Growth and Turf Quality
Authors: Fu J.M. , Koski A.J. , Qian Y.L.
Published: June 2019

Salt problems in turfgrass sites are becoming more common. The effects of mowing management on salinity tolerance are not well understood. The objective of this study was to examine the effects of three mowing regimes on turf quality and growth responses of `L-93' creeping bentgrass (Agrostis palustris L.) to salinity stress. Sods of `L-93' creeping bentgrass were grown in containers (45 cm long and 10 cm in diameter) in a greenhouse. Treatments included three mowing regimes (clipping three times weekly at 25.4 mm, four times at 12.7 mm, and daily at 6.4 mm) and four levels of irrigation water salinity (control, 5, 10, and 15 dS·m-1). The relationship of increasing soil salinity with increasing irrigation water salinity was linear in each soil layer. Increasing salinity reduced turf quality and clipping yield more severely and rapidly when mowed at 6.4 mm than at 12.7 or 25.4 mm. Regression analysis of soil salinity and turf quality suggested that turf quality of creeping bentgrass mowed to 6.4, 12.7, and 25.4 mm fell to an unacceptable level when soil salinity reached 4.1, 12.5, and 13.9 dS·m-1, respectively. Data on turf quality, clipping yield, and verdure indicated that salinity damage becomes more severe under close mowing conditions and that a moderate increase in mowing height could improve salinity tolerance of creeping bentgrass.
Overseeding Bentgrass Species into Existing Stands of Annual Bluegrass
Authors: Henry Gerald M. , Hart Stephen E. , Murphy James A.
Published: June 2019

Field trials were conducted in 2000 and 2001 to determine the potential of converting pure stands of annual bluegrass [Poa annua L. spp. reptans (Hauskins) Timm.], maintained at a 3.2-mm height, to bentgrass (Agrostis spp.). Parameters evaluated included three overseeding dates and four cultivars from two bentgrass species. Overseeding dates were 1 July, 18 Aug., and 18 Sept. 2000 and 27 June, 17 Aug., and 17 Sept. 2001. Three creeping bentgrass (A. stolonifera L.) cultivars (`Penncross', `L-93', and `Penn A-4') and one velvet bentgrass (A. canina L.) cultivar (`SR7200') were evaluated. Initial bentgrass establishment was evident across all seeding dates and cultivars in October of the year of overseeding. However, the 1 July 2000 and 27 June 2001 overseeding dates had the highest levels of bentgrass coverage 12 months after overseeding across all cultivars except `Penncross'. Coverage of `Penn A-4' and `L-93' increased to 72% in the 1 July 2000 overseeding date, 24 months after the initial overseeding. When overseeded in early summer, velvet bentgrass `SR7200' showed the greatest potential for establishment with annual bluegrass. `SR7200' and creeping bentgrass cultivars `Penn A-4' and `L-93' exhibited the greatest potential for long-term competitiveness with annual bluegrass, while `Penncross' exhibited the lowest potential.
A New Scab-resistant Apple: `Ariane'
Authors: Laurens François , Lespinasse Yves , Fouillet André
Published: June 2019

`Ariane' is a new apple cultivar carrying the Vf gene of resistance to Venturia inaequalis. It was derived from a cross made in 1979 at INRA in Angers, France between two advanced selections. The seed parent was a hybrid between the Vf cultivars `Florina' and `Prima' and the pollen parent was derived from an open pollination of `Golden Delicious'. `Ariane' matures during the same period as `Golden Delicious'. `Ariane' fruit has blushed bright red skin, with 75% of the fruit surface colored. It is medium sized. The flesh is firm and crisp; it has excellent flavor and eating quality with a high level of sugar and acid. Storage ability is long. Trees have to be thinned intensively, chemically and manually, to get good size fruit. `Ariane' shows low susceptibility to powdery mildew and fire blight. `Ariane' has been selected by the SARL (Ltd) NOVADI and the S.A.S. POMALIA to be developed as the first cultivar of a “Les Naturianes” series. Since 2002, about 95,000 trees of `Ariane' have been planted in France.
Evidence for Qualitative Suppression of Red Skin Color in Peach
Authors: Beckman T.G. , Alcazar J. Rodriguez , Sherman W.B. , Werner D.J.
Published: June 2019

Recently observed hybrid populations of peach [Prunus persica (L.) Batsch] provide evidence for the presence of a single gene suppressing red skin color. The fruit of seedling populations of FL90-48C and FL90-37C × FL84-18C, FL90-50CN × FL92-2C, FL90-48C × FL91-12, FL91-8 × FL88-6, and open-pollinated or selfed populations from unselected seedlings of `Contender' × PI65977 (`Giallo di Padova') and `Mexico Selection' × `Oro A' were rated for normal quantitative vs. no anthocyanin skin color at maturity. At this stage of development, anthocyaninless phenotypes displayed no red color over the entire surface of the fruit. Instead they were characterized by a bright yellow ground color that stood out visually in the seedling rows, and which was dubbed highlighter. The two crosses with FL84-18C yielded populations that approximated a 1:1 segregation ratio for quantitative red:no red skin color. All other crosses produced populations that closely approximated a 3:1 segregation ratio for quantitative red to no red. These data are consistent with the hypothesis that the highlighter phenotype is a single gene recessive trait. We propose the gene symbols of h and H for the recessive no red (highlighter) and dominant normal quantitative red (wild-type) alleles, respectively.
Artificial Hybridizations in Five Species of Chilean Nolana (Solanaceae)
Authors: Freyre Rosanna , Douglas Amy C. , Dillon Michael O.
Published: June 2019

Reciprocal crosses, both intraspecific and interspecific, were made among five Chilean species of Nolana (Solanaceae), a genus native to western South America. With the exception of N. paradoxa, plants of all species used were grown from mericarps collected from wild populations. Self-pollinations were generally not successful, suggesting obligate allogamy. A total of 333 hybridizations were performed, of which 109 were intraspecific and 224 interspecific. Successful intraspecific hybridizations, as measured by formation of fruits, were produced for N. acuminata (83%), N. elegans (94%), N. paradoxa (82%), and N. rupicola (100%), however viable hybrids were only obtained for N. paradoxa. Interspecific combinations resulted in over 80% fruit set, however, viable hybrid success ranged from only 1% to 5%. Crosses included N. elegans × N. paradoxa with 20 viable hybrids, N. paradoxa × N. elegans with two hybrids, N. paradoxa × N. rupicola with seven hybrids, and N. rupicola × N. paradoxa with five hybrids. Exceptions included crosses involving N. aplocaryoides, with up to 20% fruit set. Also, the combination N. paradoxa × N. aplocaryoides with five hybrids, had a 26% success. All interspecific hybrids obtained had N. paradoxa as one of the parents, which could be related to artificial selection for high germination frequency.
Pythium Root Rot Resistance in Commercial Caladium Cultivars
Authors: Deng Zhanao , Harbaugh Brent K. , Kelly Rick O. , Seijo Teresa , McGovern Robert J.
Published: June 2019

Caladiums (Caladium ×hortulanum) are popular ornamental plants widely grown for their bright colorful leaves. Pythium root rot, caused by Pythium myriotylum, is one of the few soil-borne diseases in caladium that dramatically reduces plant growth, aesthetic value, and tuber yield. Information on the reaction of caladium cultivars to P. myriotylum is not available, but would be valuable for integrated control of this disease and for breeding new resistant cultivars. Three Pythium isolates obtained from decaying roots of plants collected from a field production site and two greenhouses were evaluated for pathogenicity and potential use in experiments to screen commercial caladium cultivars for resistance. All three isolates were found to be highly virulent; they were able to cause obvious root rotting within 3 to 5 days and severe root rotting and leaf losses on susceptible cultivars within 10 days after inoculation. Nineteen major commercial cultivars were evaluated for their resistance to these isolates. Fifteen of the cultivars were susceptible or highly susceptible to Pythium infection. Four widely grown cultivars, `Candidum', `Candidum Jr.', `Frieda Hemple', and `White Christmas', were found to have a moderate level of resistance (partial resistance) to pythium root rot. Pythium infection also caused leaf discoloration, epinasty, wilting, and collapse. Regression analyses revealed a linear relationship between the root rot and leaf loss severity on Pythium-inoculated plants.
Variation in Postharvest Quality among Nordmann Fir Provenances
Authors: Nielsen Ulrik Bräuner , Chastagner Gary A.
Published: June 2019

Needle retention is an important trait when selecting for high quality Christmas trees. Nordmann fir [Abies nordmanniana (Stev.) Spach.] is generally considered to have good needle retention, but recent research has shown that when cut trees are allowed to dry, significant needle loss problems can develop. This has the potential to limit the use of this species in situations where trees are harvested early, shipped long distances, sold in warm weather markets and displayed for extended periods of time. A set of 39 provenances where tested to identify provenance differences in needle retention. Branches where collected in two consecutive years in October in 1999 and 2000 and November 2000. Small branch samples where cut and displayed indoors under controlled conditions and allowed to dry. Strong provenance differences in needle loss were seen for all three test dates. No significant interactions were seen among the October collections, but significant rank changes occurred from October to November. Predicted (BLUP) provenance mean values ranged between 11% and 27% for needle loss when branches where allowed to dry, averaging all three tests. Despite only one test location, the study clearly indicates that it should be possible to select for provenances with generally better needle retention characteristics.
Comparative Effects of Evaporative Cooling, Kaolin Particle Film, and Shade Net on Sunburn and Fruit Quality in Apples
Authors: Gindaba Jiregna , Wand Stephanie J.E.
Published: June 2019

We investigated the effects of evaporative cooling (EC), kaolin particle film (KP) and 20% shade net (SN) on the control of sunburn, fruit temperature amelioration and fruit quality of `Cripps' Pink' and `Royal Gala' apples [Malus domestica Borkh.] under orchard conditions during the 2003–04 season in Stellenbosch, South Africa. On days with maximum air temperatures of 34 to 37 °C, SN fruit were 5.4 to 9.7 °C cooler, EC fruit were 3.1 to 5.8 °C cooler and KP fruit were 1.5 to 6.4 °C cooler compared to the control (nontreated, CO) fruit. SN was effective in reducing fruit temperature from mid-morning until midafternoon; KP was most effective during late morning and early afternoon but not at midday; EC was effective from late morning on days when EC was activated. SN, followed by KP, was the most effective technique for controlling sunburn in fruit of both cultivars, with EC being less effective. The different technologies reduced fruit blush color compared to the CO treatment, with SN showing the most reduction and EC the least. EC increased fruit mass compared to all other treatments in `Royal Gala', and also increased fruit diameter and mass compared to CO in `Cripps' Pink'. We conclude that under the high radiation levels experienced in South African apple production areas, technologies which reduce irradiance as well as fruit temperature (KP, SN) are more effective in reducing sunburn than those which only reduce fruit temperature (EC). However, radiation-reducing technologies are potentially detrimental to color development on blushed apples.
Productivity and Mineral Nutrition of Limonium Species Irrigated with Saline Wastewaters
Authors: Grieve C. M. , Poss J.A. , Grattan S.R. , Shouse P.J. , Lieth J.H. , Zeng L.
Published: June 2019

To explore the possibility that saline wastewaters may be used to grow commercially acceptable floriculture crops, a study was initiated to determine the effects of salinity on two statice cultivars. Limonium perezii (Stapf) F. T. Hubb. `Blue Seas' and L. sinuatum (L.) Mill `American Beauty' were grown in greenhouse sand cultures irrigated with waters prepared to simulate saline drainage waters typically present in the western San Joaquin Valley (SJV) of California. Seven salinity treatments were imposed on 3-week-old seedlings. Electrical conductivities of the irrigation waters (EC) were 2.5 (control), 7, 11, 15, 20, 25, and 30 dS·m–1. Vegetative shoots were sampled for biomass production and ion analysis ten weeks after application of stress. Flower stem numbers, length, and weight were determined at harvest. Stem length of L. perezii was significantly reduced when irrigation water salinity exceeded a threshold of 2.5 dS·m–1. Salt tolerance threshold based on stem length for L. sinuatum was 7 dS m-1. The species exhibited significant differences in shoot-ion relations which appear to be related to differences in salt tolerance. Sodium, K+, Mg2+, and total-P were more strongly accumulated in the leaves of L. sinuatum than L. perezii. Both species accumulated K+ in preference to Na+, but selectivity for K+ over Na+ was significantly higher in L. sinuatum than in the more salt-sensitive L. perezii. Chloride concentration in L. sinuatum leaves increased significantly as salinity increased, whereas the 20-fold increase in substrate-Cl had no effect on leaf-Cl in L. perezii. Both Limonium species completed their life cycles at salt concentrations exceeding 30 dS·m–1, a character associated with halophytic plants. Maximum growth of each species, however, occurred under relatively low salt stress, and steadily declined as external salinity increased. Based on this crop productivity response, L. perezii should be rated as sensitive and L sinuatum as moderately tolerant.
Nondestructive Estimation of Anthocyanin Content in Autumn Sugar Maple Leaves
Authors: van den Berg Abby K. , Perkins Timothy D.
Published: June 2019

A field-portable tool for nondestructive foliar anthocyanin content estimation would be beneficial to researchers in many areas of plant science. An existing commercial chlorophyll content meter was modified to measure an index of anthocyanin content. The ability of the experimental anthocyanin meter (ACM) to estimate total extractable anthocyanin content was tested in sugar maple (Acer saccharum Marsh.) leaves representing several subjective color categories collected from a variety of field sites in northwestern Vermont on several dates in Autumn 2003. Overall, there was a significant linear relationship between anthocyanin content index (ACI) and total extractable anthocyanin content (r2 = 0.872, P < 0.001). Therefore, the ACM appears to be an effective tool for estimation of relative anthocyanin content in large samples of autumn sugar maple leaves.
Separation of Citrus Tristeza Virus Isolates in Mixed Infections through Transfer by Single Brown Citrus Aphids
Authors: Powell Charles A. , Lin Youjian
Published: June 2019

One hundred single brown citrus aphid (BCA) (Toxoptera citricida Kirkaldy) transmission attempts were made from each of 16 different citrus trees [8 grapefruit (Citrus paradisi Macf.) and 8 sweet orange (C. sinensis (L.) Osbeck)] previously inoculated with decline-inducing (T36-CTV), non-decline-inducing (T30-CTV), a mixture of the two Citrus tristeza virus isolate types, or no CTV. Successful CTV transmission occurred in 1.5% of attempts from grapefruit trees that had been bark-chip-inoculated with T36-CTV, 3% of attempts from orange trees inoculated with T36-CTV, 3% of attempts from grapefruit trees inoculated with both T36- and T30-CTV, 4% of attempts from orange trees inoculated with both T36- and T30-CTV, 1.5% of attempts from grapefruit trees inoculated with T30-CTV, and 3.5% of attempts from orange trees inoculated with T30-CTV. Single BCA were able to recover T30-like-CTV from trees believed to be inoculated only with T36-CTV, and T36-like-CTV from trees believed to be inoculated only with T30-CTV, suggesting that these inoculum sources were also mixtures of T36-CTV and T30-CTV. The T36-CTV was not immunologically detectable in some of the trees from which it was transmitted indicating that single BrCA can recover T36-CTV from a T36-CTV/T30-CTV mixture in which the T36-CTV is an undetectable, minority component.
Phytotoxicity Associated with Drip-applied 1,3-Dichloropropene and Chloropicrin in Vegetables Produced with Plastic Mulch
Authors: Desaeger Johan , Csinos Alex
Published: June 2019

The effects of drip-applied 1,3-dichloropropene (1,3-D) and chloropicrin on fumigant soil gas levels and growth of vegetable seedlings were investigated in three separate tests in Tifton, Ga. Tests were conducted in Spring 2002, Fall 2002, and Spring 2003. Phytotoxicity of 1,3-D + chloropicrin was induced in the 2002 tests by applying progressively higher rates (0 to 374 L·ha–1) of drip-irrigated InLine (an emulsifiable formulation (EC) containing 60.8% 1,3-D and 33.3% chloropicrin) and planting vegetable seedlings within four days after application. Vegetables evaluated were tomato, pepper and cucumber (Spring 2002), and tomato and squash (Fall 2002). In Spring 2003, the effects of 1,3-D formulation (InLine versus Telone EC, an EC containing 94% 1,3-D), plastic mulch type [low density polyethylene (LDPE) versus virtually impermeable film (VIF)] and drip tape configuration (one versus two drip tapes) on fumigant soil gas levels and growth of tomato were investigated. Tomato was planted after the recommended 3-week waiting period. Fumigant concentrations in soil were measured using Gastec detection tubes at 1 to 4 days after drip fumigation in all three tests. Measured fumigant soil gas concentrations were correlated with fumigant application rates in Spring 2002, but not in Fall 2002. Vegetables were visibly affected by residual fumigant levels in the soil and showed symptoms such as leaf chlorosis (cucumber, squash and pepper), leaf bronzing (tomato) and stem browning and stunting (all crops). Fumigant soil air levels were negatively and linearly correlated with different plant growth parameters, in particular plant vigor. The cucurbit crops showed an immediate response and high mortality within 1 week after planting. Surviving plants recovered well in fall. The solanaceous crops showed a more delayed response and lower mortality rates. However, phytotoxic effects with tomato and pepper were more persistent and plants did not seem to recover with time. Overall, fumigant residue levels and potential phytotoxicity were greater in spring than in fall. Greater fumigant soil concentrations were measured under VIF as compared to LDPE plastic mulch. The effect of drip-tape configuration varied with the type of plastic mulch that was used. The double-tape treatment resulted in lower fumigant levels at the bed center under LDPE mulch, and higher fumigant levels at the bed shoulder under VIF mulch. The formulation containing 94% 1,3-D resulted in higher soil fumigant levels as compared to the formulation containing 61% 1,3-D and 33% chloropicrin, especially with VIF mulch. Early plant vigor of tomato was negatively correlated with fumigant soil gas levels, and was especially poor following drip fumigation with 94% 1,3-D under VIF mulch.
Gas Composition and Temperature Affect Quality of Fresh-cut Fennel
Authors: Escalona V.H. , Artés-Hernández F. , Artés F.
Published: June 2019

Freshly harvested bulbs of fennel (Foeniculum vulgare var. dulce) `Clio' were sliced at 5 °C, dipped in 100 mg·L–1 NaOCl solution, and packaged in passive modified atmosphere packaging (MAP) by using trays covered and thermal sealed with unperforated or perforated polypropylene film. According to common commercial needs a shelf life of 14 d at 0 and 5 °C was applied. The respiration rate of fresh-cut fennel was 1.3- to 1.7-fold higher at 5 °C than at 0 °C, and was 1.4- to 1.8-fold higher than that reported for whole bulbs. MAP did not prevent the declines in SSC and TA that occurred during storage, while pH did not change. Water loss was lower than 0.1% in all treatments, and no decay or physiological disorders developed during storage. The gas compositions of 16 to 18 kPa O2 plus 2 to 4 kPa CO2 generated within the perforated packages at 0 and 5 °C or 1.5 to 2 kPa O2 plus 18 to 20 kPa CO2 in unperforated packages at 5 °C did not inhibit browning on the cut surface or other sensory changes of the slices. However, atmospheres in unperforated packages of 4 to 6 kPa O2 plus 10 to 14 kPa CO2 at 0 °C maintained the sensory quality like at harvest.
Micropropagation of Two Selected Male Kiwifruit and Analysis of Genetic Variation with AFLP Markers
Authors: Prado M.J. , Herrera M.T. , Vázquez R.A. , Romo S. , González M.V.
Published: June 2019

A simple and reliable protocol for micropropagation during 12 subcultures of two field growth male plants of kiwifruit [Actinidia deliciosa (A.Chev.) Liang and Ferguson] is described. The best results of shoot multiplication and elongation were obtained in Cheng's K(h) medium in the presence of 0.5 μm NAA, 22 μm BA and 1.4 μm GA3 for `Tomuri' explants, and of 0.1 μm NAA, 4.4 μm BA, and 0.3 μm GA3 for clone A explants. In addition, the cytokinin compounds TDZ and mT were also tested allowing improving the multiplication rate in `Tomuri' explants. For rooting, `Tomuri' and clone A developed shoots were treated by basal immersion in a 5 mm IBA solution for 15 seconds. Treated shoots were then cultured in half-strength K(h) medium without growth regulators showing 100% rooting after 30 days. Regenerated plantlets were successfully transplanted to soil (90% survival) and they are actively growing in the field. Somaclonal variation analysis by AFLP was carried out using 15 primer combinations, yielding reproducible and well-resolved bands with a 57% of polymorphism. AFLP markers showed to be effective to discriminate genetic variation in this species, being greater in clone A than `Tomuri'. Chemical names used: N6-benzyladenine (BA); gibberellic acid (GA3); indole-3-butyric acid (IBA); meta-topolin (mT); naphthaleneacetic acid (NAA); thidiazuron (TDZ).
Response of In Vitro Strawberry to Silver Nitrate (AgNO3)
Authors: Qin Yonghua , Zhang Shanglong , Zhang Lingxiao , Zhu Daoyu , Syed Asghar
Published: June 2019

Response of Toyonoka strawberry to AgNO3 was studied. Types and combinations of plant growth regulators had significant effects on shoot regeneration efficiency. Explants cultured for 10 days in shoot regeneration medium in the presence of AgNO3 not only enhanced shoot regeneration efficiency but also expedited the initiation of adventitious buds. Highest regeneration (87.38%) and number of shoots per explant (11.67) were achieved in shoot regeneration media containing 1.5 mg·L–1 TDZ, 0.4 mg·L–1 IBA and 1.0 mg·L–1 AgNO3. Half-strength MS containing 1.0 mg·L–1 AgNO3 was an optimum medium for rooting. AgNO3 advanced root emergence and increased percent rooting, root length, dry weight and activity. Lower concentrations of AgNO3 inhibited ethylene production and promoted shoot regeneration and growth. It had a significant stimulatory effect on chlorophyll, soluble protein contents and antioxidant enzyme activities. Chlorophyll and soluble protein contents, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were increased in the presence of AgNO3 and reached maximum at 1.0 mg·L–1 AgNO3. Root water content, superoxide free radicals (O2.-), malondialdehyde (MDA) content, proline accumulation and IAA-oxidase activity in leaves were increased while (IAA) content was decreased in the presence of AgNO3. Chemical names used: indole-3-butyric acid (IBA); silver nitrate (AgNO3); thidiazuron (TDZ); N6-benzyladenine (BA); 2,4-dichlorophenoxy acetic acid (2,4-D); indole-3-acetic acid (IAA); α-naphthalene acetic acid (NAA); gibberellic acid (GA3); bovine serum albumin (BSA); 2,3,5-triphenyl-2H-tetrazolium chloride (TTC).
Inoculation with Ericoid Mycorrhizal Fungi Alters Fertilizer Use of Highbush Blueberry Cultivars
Authors: Scagel Carolyn F.
Published: June 2019

Seven highbush blueberry cultivars were inoculated with one of three different isolates of ericoid mycorrhizal fungi (EMF) and grown in pots for 2 years with either inorganic or organic fertilizer. Root colonization of noninoculated plants was low (<15%) regardless of fertilizer source. Root colonization on inoculated plants was 15-30%. Colonization was typically higher when plants were grown with organic fertilizer. Inoculation generally increased plant growth but decreased root:shoot biomass ratios regardless of the type of fertilizer used. Inoculation also increased nutrient uptake and/or nutrient use efficiency in several cultivars, particularly when plants were fertilizer with organic fertilizer. Without inoculum, however, some cultivars fertilized with organic fertilizer had less growth and lower concentrations of N, K, S, and Cu than those fertilized with inorganic fertilizer. Cultivars that were genetically close in ancestry showed a high degree of variability in response to mycorrhizal fungi, while responses to fertilizer type were similar in closely related cultivars. Results suggest that nutrient availability may influence colonization and growth responses to EMF; however aspects of fungus–host specificity and inoculum availability also play a role in EMF colonization of roots in container production.
Muscadine Grape Response to Drip Irrigation Rate
Authors: NeSmith D. Scott
Published: June 2019

During 1997 through 1999 mature `Southland' muscadine grapes were grown in Griffin, Ga., with different rates of daily irrigation. Irrigation rates were 0, 15, 22.5, and 30 L·d–1, supplied to individual plants through two emitters. Substantial water deficit occurred during August 1997, May and June 1998, and July and August 1999. The greatest yield response to irrigation was observed during 1998. No significant response to irrigation was observed during 1999, even though soil water was greatly depleted in the upper 30 cm late in the season for control plants. The 3-year average response of total yield indicated a significant response to irrigation, with the greatest yield occurring at the 22.5-L·d–1 rate. Together these data suggest that muscadine grapes respond to irrigation, especially when water deficits during the early to midseason are prevalent. With single trellis vines, 22.5 L·d–1 should provide adequate water in warm, humid regions similar to the southeastern U.S.
Foliar Damage, Spectral Reflectance, and Tissue Ion Concentrations of Trees Sprinkle Irrigated with Waters of Similar Salinity but Different Chemical Composition
Authors: Devitt D.A. , Morris R.L. , Fenstermaker L.K.
Published: June 2019

We investigated foliar damage to five landscape species sprinkler irrigated with either reuse water or one of five synthesized saline waters that contained elevated single salts mixed with Colorado River water, all having similar electrical conductivities. The experiment allowed us to compare the impact of elevated concentrations of Na, Mg, Ca, Cl, and SO4 on an index of visual damage (IVD), tissue ion concentrations, and spectral reflectance. Waters containing elevated concentrations of MgCl2 or NaCl caused greater foliar damage than did MgSO4, Na2SO4, CaSO4, or reuse water, as recorded in higher IVD values (p < 0.05). Privet and elm were damaged to a greater extent (higher IVD values) than were desert willow, guava and laurel (p < 0.05). Higher IVD values were recorded for all species irrigated with the MgCl2 waters, with mortality recorded in privet. Tissue nutrient concentrations were correlated with the IVD values. In the case of guava, 61% of the variability in the IVD could be accounted for based on N, P and K (P < 0.01). On a treatment basis, the single salts added to the municipal water showed little correlation with the IVD values, except in the case of MgCl2, where Mg was included in the regression equation (r2 = 0.82, P < 0.01, IVD↑ as S04↓, Mg and P↑). Eleven different spectral indices separated based on treatment and/or species (P < 0.05). In elm, 70% of the variability in the IVD could be accounted for by including Red Edge, Normalized Difference Vegetation Index (NDVI) and Water Band Index (WBI)/NDVI. A mixed response was observed to a post 30-day irrigation rinse in an attempt to reduce IVD values. Based on our results, care should be given to monitoring not only the EC (and osmotic potential) but also the ionic composition when saline waters are blended with other water sources, with the aim of minimizing the concentration of Mg, Cl, and Na.
A WEB-ACCESSIBLE GEO-REFERENCED DATABASE OF SWEETPOTATO ACCESSIONS FOR TANZANIA AND KENYA
Authors: Villordon A. , Gichuki S. , Kulembeka H. , Jeremiah S.C. , Labonte D.
Published: June 2019

One of the secondary centers of genetic diversity for the sweetpotato [Ipomoea batatas (L.) Lam.] is located in Africa. We have developed a geo-referenced database of sweetpotato accessions for Tanzania and Kenya that is accessible by stakeholders and other users. Public domain base maps and other files were used to generate the underlying GIS components. DIVA-GIS was used to convert existing spreadsheet-based accession and passport data into GIS-compliant files. ALOV Map, a public domain Java application for publishing vector and raster maps, was used to provide the framework for a web-accessible GIS database. This demonstrates that the availability of publicly available software requiring minimal or flexible licensing costs provide a cost-effective alternative to institutions that are considering developing GIS databases as well as enabling web accessibility to such resources. DIVA-GIS was also used to predict potential distribution of sweetpotato germplasm in Sub-Saharan Africa using the built-in ecological niche modelling tool. We describe procedures, software, and other applications that we used to develop a publicly accessible web interface to a GIS database of sweetpotato germplasm collections in Kenya and Tanzania.
UPDATE ON POWDERY MILDEW RESISTANCE SCREENING IN WATERMELON
Authors: Davis Angela R. , Wehner Todd C. , Levi Amnon , King Stephen R.
Published: June 2019

Powdery mildew has been reported on Citrullus lanatus in Africa and Europe for the past nine years, and in the United States for the past 6 years. During this time, it has occurred in the main watermelon production areas in the U.S. and has been documented in nine states (South Carolina, Georgia, Florida, Oklahoma, Texas, Maryland, New York, Arizona, and California). This is of great concern to the watermelon industry since powdery mildew is difficult to control and can have a severe impact on yield and fruit quality due to loss of photosynthetic area and sunscald. Finding resistant C. lanatus germplasm is needed for the development of commercial varieties containing this resistance. This report summarized the status of an ongoing project to screen the entire USDA–ARS C. lanatus germplasm collection. Currently, the collection is being screened for race 1 and race 2 Podosphaera xanthii (syn. Sphaerotheca fuliginea auct. p.p.), the causal agent of powdery mildew in C. lanatus in the United States. Resistance genes appear to exist for both races and the genes conferring resistance to race 1 appear to be different than race 2 resistance genes. Allelism tests are currently in process to determine the number of resistance genes present.