bluuebunny/crossref_metadata_2025 huggingface dataset:
043 Interspecific Hybridizations between the Native Bittersweet Celastrus scandens and the Introduced Invasive Species C. orbiculatus
Authors: Pooler Margaret R. , Dix Ruth L. , Feely Joan
Published: February 2019

The issue of invasive plants has become a concern to a variety of groups, including environmentalists, policymakers, and nurserymen. Although many surveys of invasive plants have been made, little research on the biology of hybridization has been conducted. Bittersweet (Celastrus) species serve as a good model system to test the effects of interspecific hybridizations since native and introduced species are found in the U.S. The American bittersweet (Celastrus scandens L.) is a deciduous climbing or twining shrub native to eastern and central North America. Although the bark has been used for medicinal purposes, the plant is cultivated as a nursery crop primarily for its bright red berries. In its natural habitat, native bittersweet is also an important source of food and cover for wildlife. Over the past several decades, populations of native bittersweet have declined to such low levels that some states are considering listing it as a threatened species. One reason for the rarity of American bittersweet in the wild is thought to be competition and possibly hybridization with an aggressive introduced species, oriental bittersweet (Celastrus orbiculatus Thunb.), which was introduced from Asia into the U.S. in 1860 as an ornamental. This plant can form dense, tangled, impenetrable thickets or climb small trees to girdle and smother them. It has been seen in at least 21 states since it was first recorded as an escape plant in 1912. Our objective was to determine whether oriental bittersweet can hybridize with native bittersweet, thus contributing to the loss of native populations in the United States. We performed controlled pollinations using C. scandens as the female parent and C. scandens or C. orbiculatus as the male parent. Although the intraspecific pollinations resulted in significantly more germinating seedlings than the interspecific crosses, the seedlings from the interspecific crosses had less seed dormancy and were more vigorous and more quick to vine than the intraspecific seedlings. These results indicate that the decline of the American bittersweet may be due to interspecific hybridizations with the invasive introduced species.
048 Effects of Inbreeding in a “Wisconsin Fast Plants” Brassica rapa Population
Authors: Luy Federico L. Iniguez , Nienhuis James
Published: February 2019

Wisconsin Fast Plants (WFP) are small, rapid-cycling Brassica rapa populations that were developed by Paul Williams in the Dept. of Plant Pathology at the Univ. of Wisconsin, to facilitate classroom demonstration of biological principals. WFP exist as heterogenous populations, which have been selected for expression of different mutant phenotypes. Because of self-incompatibility mechanisms, it has been difficult to develop inbred lines of WFP via self-feritilization. Our objective was to inbreed a WFP population through full-sib mating. Genetic diversity was calculated for eight individuals from each of eight different WFF population, using 69 polymorphic RAPD (molecular marker) bands. The eight different WPF populatons were randomly mated (via chain crossing) for two generations. Six cycles of full-sib mating were initiated on 130 random families. After six cycles of full-sib mating, 79 families remain. The loss of families, during the process of inbreeding, may have been due to selection or drift. However, the expectation is that genetic variance will increase. The 79 inbred families express an array of different WFP phenotypes, e.g., anthocyanin pigmentation, yellow cotyledon, plant height, and seed color at different combinations in different inbred lines.
052 In Vitro Culture Initiation and Proliferation of Exochorda racemosa
Authors: Yang Guochen , Kamp-Glass Marihelen
Published: February 2019

Exochorda racemosa is an ornamental shrub with white flowers that is spiraea-like, deciduous, and hardy. The buds resemble pearls. Normally it is propagated by seeds, layers, and cuttings of softwood. However, it is a slow process that takes a few years to produce a reasonable size plant for the demanding market. Our objective was to establish a successful in vitro culture and to rapidly multiply this ornamental species. Softwood explant materials were collected from a local nursery and were disinfested with 15% bleach solution and rinsed three times with sterile distilled and deionized water. In vitro cultures were established and maintained in woody plant medium (WPM) supplemented with BA at 0.1 mg·L-1, 3% sucrose, and 0.7% agar with the pH adjusted to 5.8. Then shoots were transferred to the multiplication medium containing BA, CPPU, or thidiazuron (TDZ) at various concentrations. Preliminary results show that explants cultured on medium containing TDZ produced the best shoot proliferation.
053 The Origin of Raphanus sativus Based on the DNA Sequences from Different Organelles
Authors: Yang Yau-Wen , Tai Pai-Yean , Chen Ying
Published: February 2019

There are two evolutionary pathways in the genus of Brassica, one is rapa/oleracea lineage and the other is nigra lineage. Based on the morphological characteristics and nuclear RAPD or RFLP markers, genus Raphanus was thought more closely related to nigra lineage than to rapa/oleracea lineage (Song et al., 1990; Thormann et al., 1994). RFLP data of both chloroplast and mitochondria revealed that Raphanus is more closely related to rapa/oleracea lineage (Palmer and Herbon, 1988; Warwick and Black, 1991; Pradhan et al., 1992). We have previously demonstrated that Raphanus sativus is more closely related to nigra lineage using nuclear intergenic spacer between 5S rDNA and internal transcribed spacer region between 18S and 25S rDNA. In this study, we analyzed DNA sequences from different regions of chloroplast and showed that Raphanus sativus was closely related to rapa/oleracea lineage than to nigra lineage. These results suggest that Raphanus sativus is a hybrid between B. rapa/oleracea and B nigra lineages as proposed by Song et al (1990). The split time between these two lineages and the divergent time of Raphanus was also determined based on these chloroplast DNA sequences.
067 Analysis of Protein Expression and Resistance to Bacteria in Transgenic Potatoes with Antimicrobial Gene
Authors: Yi Jung-Yoon , Seo Hyo-Won , Cho Ji-Hong , Park Kuen-Woo
Published: February 2019

Anti-bacterial peptide gene (shiva) was introduced into potato plants to improve the resistance to bacterial diseases. The 21 potato clones were selected in the medium containg 50 mg/L kanamycin and 13 transformants were confirmed by GUS activity assay using 4-methylumbellyferyl glucuronide (MUG) and PCR by NPTII specific primer sets. A 0.5-kb band was confirmed by PCR in the most transformants of T0, T1, and T2 generations. As a result of PCR with primer set chosen at shiva and GUS, expected 690-bp fragments were produced in the most transformants of T0, T1, and T2 generations. For southern blot analysis, potato genomic DNA digested with HindIII was separated on 0.7 % agarose gel, transferred to nylon membranes, and detected with nitroblue tetrazolium salt (NBT). As a result of southern analysis, different single bands were detected in the transformants with tPAL5 promoter and 1 to 3 bands were acquired in the transformants with CaMV35S promoter. To analysis protein level of transformants, NPTII ELISA kit were used. In several transformants, optical density (O.D.) values were 10- to 20-fold higher than non-transformants. Tubers were screened for resistance to Erwinia carotovora subsp. carotovora. The concentration of the inocula was 106 cells/mL. After inoculation, tuber slices were incubated aerobically for 48 h at 20 °C. The symptoms of soft rot in transgenic plants were considerably weakened in comparison with non-transformants.
070 Genetic Identification of Oncidium Varieties by RAPD Markers
Authors: Chen Fure-Chyi , Wu Wan-Ling , Pan Chun-Hua , Chu Irwin Yau-Yuan , Yang Yau-Wen
Published: February 2019

Molecular markers by random amplified polymorphic DNAs were used to evaluate the genetic variation among different Oncidium accessions. It is possible to distinguish different registered Oncidium hybrids, including Gower Ramsey, Sweet Sugar, and Taka using nine random primers. Furthermore, variation was also detected within different cultivars derived from same hybrids. For example, several cultivars of Gower Ramsey could be distinguished based on molecular markers. Based on dendrogram, the investigated cultivars were clustered into several groups. Onc. Gower Ramsey and its selected cultivars were in one group. Onc. Sweet Sugar, Onc. Taka and Onc. Sharry Baby `Sweet Fragrance' were clustered in separate groups.
079 Production of Microprotoplast from Swiglea glutinosa for Chromosome Transfer in Citrus
Authors: Louzada Eliezer , Del Rio Sonia , Xia Dianren
Published: February 2019

The development of improved orange and grapefruit varieties via conventional breeding is not possible due their high degree of apomixis. The currently available varieties originated through natural or induced mutation. The development of a alternative breeding method is urgently needed for these citrus group. Microprotoplast Mediated Chromosome Transfer (MMCT) provides a direct way to transfer a very limited portion of the genome (one or more chromosome) from a donor species to a recipient species. In mammalian cells this procedure has been a powerful tool for gene mapping and to study the regulation of gene expression. Until recently, no chemical treatment was known for an efficient induction of microprotoplat in plants. Recently, amiprophosmethyl (APM) and cremart was found to be very efficient for the mass production of microprotoplasts in the Solanaceae family enabling a single chromosome to be transferred from potato to tomato and tobacco. To establish this technology in citrus, the efficiency of APM for the mass induction of microprotoplast from Swiglea glutinosa, a wild relative of citrus, was studied. APM ranging from 16 to 32 μmol was effective on promoting the scattering of the chromosomes and to create multinucleated cells. The microprotoplasts will be used in chromosome transfer experiments.
087 Determining S-genotype of Japanese Apricot (Prunus mume) Cultivar
Authors: Yaegaki H. , Shimada T. , Hayaman H. , Haji T. , Yamaguchi M.
Published: February 2019

Japanese apricot (Prunus mume) originated in south-eastern China and is one of the major fruit trees in Japan. The major cultivars of Japanese apricot are self-incompatible. Self-incompatibility of Japanese apricot is gametophytic, the same as other Prunus species. Since S-genotype of every cultivar remained unclear until now, we examined molecular markers to determine S-genotype which was explored based on the information about S-RNase of other Prunus spiecies. Total DNA isolated from six cultivars was PCR-amplified by oligonucleotide primers designed from conserved region of Prunus S-RNase Every six cultivars yielded two amplified bands. In total, seven kind of polymorphism in molecular size were determined among those six cultivar, controlled pollination tests were carried out among cultivars that showed same band pattern, and these cross-combinations indicated cross-incompatibility. So, we were made clear that S-genotype of Japanese apricot could effectively and easily be determined by PCR method, and that there exists seven S-gene at least.
090 Identification and Genetic Relatedness among Pecan Cultivars Detected by Randomly Amplified Polymorphic DNA (RAPD) Analysis
Authors: Conner Patrick J. , Wood Bruce W.
Published: February 2019

Genetic variation among pecan [Carya illinoinensis (Wangenh.) K. Koch] cultivars was studied using randomly amplified polymorphic DNA (RAPD) markers. Using a combination of primers, a unique fingerprint was produced for each of the pecan genotypes studied. The genetic relatedness between 44 cultivars was estimated using more than 100 RAPD markers. Genetic distances based on the simple matching coefficient varied from 0.91 to 0.59. The phenetic dendogram developed from cluster analysis showed relatively weak grouping association. However, cultivars with known pedigrees usually grouped with at least one of the parents and genetic similarity estimates appear to agree with known genetic relationships. Using RAPD information in determining genetic relationships among pecan cultivars with unknown or questionable pedigrees and the integration of that knowledge into the breeding program is discussed.
092 Evaluating Seasonal Color Changes and Storage Conditions for Woody Plant Branches Used in the Floral Trade
Authors: Kleeberger K.S. , Moser B.C.
Published: February 2019

A number of deciduous woody ornamental plants experience seasonal changes in stem pigmentation. The resulting coloration yields plants desirable for use as cut branches in the florist trade. The dynamics of color change are particularly important in identifying harvest periods based on optimum color. The characterization of this process has been investigated for Cornus (Cornus baileyi, Cornus sericea `Cardinal', Cornus sericea `Flaviramea', Cornus alba `Bud's Yellow') and Salix (Salix matsudana `Tortosa', Salix `Golden Curls', Salix `Scarlet Curls') cultivars. Seasonal color changes are presented in relation to date. These data were compared to chlorophyll and anthocyanin levels to further characterize pigmentation change. Because size and round stem shape are not conducive to traditional tristimulus color measurement techniques, L*a*b* measurements were obtained from images imported via computer scanner as CIELAB images. L*a*b* values then were used to determine hue angle and chromaticity for each sample date. Postharvest storage duration and conditions are evaluated with regard to moisture content and color retention in cut branches.
093 Miniature Rose Flower Longevity in Response to Ethylene Is Not Affected by Seasonal Growing Conditions
Authors: Grossi Jose Antonio S. , Pemberton H. Brent , Roberson William E.
Published: February 2019

The effect of exogenous ethylene was investigated on single-stemmed plants of Rosa L. `RUIdodo', `RUIrosora', `RUIjef', `MEIferjac', `MEIshulo', `MEIghivon' and `MEIgagul' grown in controlled environment growth chambers simulating summer-like and winter-like conditions. When the flower on each plant reached developmental stage 2 (showing color, calyx reflexing, no petals reflexed), the plants were placed for 18 h in plexiglass chambers with ethylene at 0, 0.1, 0.5, 1.0 and 5.0 μL·L-1 under a simulated interior environment at 21 °C with 14 μmol·m-2·s-1 fluorescent light. Under the same interior environment, the plants were kept for postharvest evaluation. Response to ethylene of all cultivars was not affected by the difference in growing conditions. As shown previously by other authors, however, the ethylene reduced flower longevity. Treatment with 0.1 μL·L-1 of ethylene reduced flower longevity by 1 day in comparison to the control (0 μL·L-1). The ethylene concentrations of 1.0 μL·L-1 and 5.0 μL·L-1 reduced flower longevity by 3 days. Regardless of ethylene concentration or growing conditions, `RUIjef' and `MEIferjac' exhibited the longest flower longevity and `MEIghivon' and `MEIgagul' the shortest flower longevity. All cultivars, except `RUIrosora', exhibited the longest flower longevity under summer-like vs. winter-like conditions, with the difference ranging from 1.5 to 5 days. `RUIrosora' exhibited similar flower longevity regardless of growing conditions. Differences in flower longevity in response to seasonal growing conditions have been found by us and other authors, but the cultivars used in this study have not been previously studied. This difference in flower longevity as a response to growing conditions cannot be explained by differences in response to ethylene so that other factors must be involved.
096 Disease Incidence in Fresh-cut Peony Flowers after Long-term Cold Storage
Authors: Gast Karen L.B.
Published: February 2019

Fresh-cut peonies are one of few cut flowers that can be stored for weeks and still provide a marketable flower. Peonies are usually marketed by color: reds, pinks, whites, and corals. Several different cultivars may be included in each color depending on their country of origin and time during the harvest season. Previous work with peonies has shown that different cultivars of the same color may behave differently during postharvest handling, whether it is storage life, vase life, opening time, storage temperature, etc. One problem of long-term cold storage is diseases that may render flowers unmarketable. This study evaluated the effect of four storage disease prevention treatments on seven peony cultivars, two reds, two pinks, and three whites, stored at 1 °C. The four disease prevention treatments included a control, methyl jasmonate during storage, a pre-storage calcium chloride pulsing for 2 h at room temperature, and a pre-storage fungicide spray. Flowers were evaluated for disease incidence on leaves and flowers, and for flower bud openness after 4, 8, and 12 weeks of cold storage. Overall results support previous work that shows peony cultivars react differently to postharvest treatments. Two cultivars were greatly affected by the disease prevention treatments and three were moderately affected, while there were few treatment effects seen with the other two. The calcium chloride pulse produced the greatest disease incidence and resulted in the flowers being more opening, which is not desirable. There was often no difference in the control, methyl jasmonate, and fungicide treatments. It appears that pre-storage treatments may not be beneficial for some fresh-cut peony cultivars.
097 Growth Regulator Application Improves Postharvest Quality of Cut Lilies
Authors: Han Susan S.
Published: February 2019

Effects of the duration of cold storage, as well as the concentrations, timing, and means of application of a growth regulator solution on the postharvest quality of cut Oriental and Asiatic lilies were evaluated. Without cold storage, lower leaves of Oriental lily `Stargazer' began to turn yellow ≈1 week after placing stem in an interior environment. The development of leaf yellowing continued to progress upward until the end of the vase life when there was an average of >25% chlorotic leaves. Cold storage worsened the leaf disorder. The longer the duration of cold storage, the earlier the development of leaf yellowing and the higher the percentage of leaves that were chlorotic. Spraying leaves with a solution containing 25 mg·L-1 each of BA and GA4+7 significantly reduced cold-storage-induced leaf yellowing and bud abortion in both Oriental and Asiatic lily. Concentration of the growth regulator solution was inversely related to the development of leaf yellowing. Timing of the growth regulator application was not critical, as there were no differences in leaf yellowing or bud development when the growth regulator solution was sprayed before or after the cold storage. Addition of the growth regulators to the preservative solution completely prevented leaf yellowing but also induced bud abortion. For practical application, spraying growth regulators prior to or after the cold storage would significantly improve the postharvest quality of cut lilies.
108 Maintaining Postharvest Quality of Mango Fruit with Methyl Jasmonate
Authors: González-Aguilar G.A. , Buta J.G. , Wang C.Y.
Published: February 2019

Treatment of mango (Mangifera indica cv Kent) with methyl jasmonate (MJ) vapor for 20 h at 20 °C was effective in reducing chilling injury (CI) symptoms and decay, and enhancing skin color development. MJ (10-4 M) was the most effective concentration for reducing CI and decay in fruit stored at 5 °C followed by 7 days at 20 °C (shelf life period). The use of 10-5 M MJ enhanced yellow and red color development of mango kept at 20 °C. These fruit possessed higher L*, a* and b* values than controls and those treated with 10-4 M MJ. Ripening processes were inhibited by cold storage in control fruits. After cold storage (5 °C) and the shelf life period, fruit treated with 10-5 M MJ fruit ripened normally and contained the highest total soluble solids (TSS). These fruit maintained higher sugar and organic acid levels than those in other treatments. We concluded that MJ treatment could be used to reduce decay and CI symptoms, and also to improve color development of mango fruit without adversely affecting quality.
112 Effects of Edible Plant Oil Emulsions on Storage Disorders in `Elegant Lady' Peaches
Authors: Duan Yousheng , Ju Zhiqiang , Ju Zhiguo
Published: February 2019

Effects of different plant oils (soybean, corn, peanut, cottonseed, conola, sunflower, safflower, rape seed, and linseed) on mealiness, leatheriness, and flesh browning (FB) in `Elegant Lady' peaches (Prunus persica Batsch) were studied. Fruit were harvested at three dates (10 days apart) with the second harvest concomitant to commercial harvest, dipped in a 5% or 10% oil emulsion for 3 min, and stored at 0 or 5 °C, respectively. After 6 weeks at 0 °C, fruit developed more leatheriness and FB but less mealiness in early harvested compared to late-harvested fruit. When stored at 5 °C, fruit did not develop any leatheriness regardless of harvest dates, but fruit from the last harvest developed high levels of mealiness and FB compare with fruit from the other two harvests. FB was found only, but not in all, leathery or mealy fruit. None of the oils affected leatheriness, but all reduced mealiness to the same extent at the same concentration. Oil treatments controlled FB completely in both leathery and mealy fruit. Oil at 10 % was more effective in controlling mealiness and FB than at 5%. Oil-treated fruit had higher flesh firmness and titratable acidity and developed less decay than the controls at removal from storage.
119 The Involvement of Ethylene on the Incidence of Core and Skin Browning in Stored `Niitaka' Pears
Authors: Hwang Y.S. , Lee J.C. , Lee B.J.
Published: February 2019

Oriental pear, `Niitaka', often suffers from skin and/or core browning when storage duration is extended. Skin browning occurred in aged fruit differs from browning disorder occurred at the early stage of low temperature storage (within 1 month), which is dark in color. This disorder can be inhibited by temperature conditioning through stacking fruit under shade for 7 days. Unlike dark browning disorder, fruit affected by light browning disorder often develops core browning. Also, when the duration of temperature conditioning is extended, light browning disorder occurred more rapidly even at 0 °C. In this experiment, the effect of external application of ethylene and ethylene scrubbing in storage environment was examined. Light browning disorder increased when fruit were wrapped with polyethylene film (30 μm) and the application of ethylene scrubber effectively decreased this disorder. Skin peeling was also observed in disordered fruit. The application of ethylene resulted in the increase of light browning on skin and core browning. Thus, both disorders seemed to be involved with senescence. The involvement of ethylene on both disorders will be further discussed.
120 Effects of Short-term Postharvest Treatments on Cilantro (Coriandrum sativum L.) Storage Quality
Authors: Mangan Francis X. , Kozower Claire , Bramlage William
Published: February 2019

Latinos are 6% of the population of Massachusetts and are the largest and fastest-growing ethnic minority in this state. Due to the increase in Latinos and other ethnic groups, farmers in Massachusetts are diversifying their crops to meet the demands of these new markets. Cilantro is a popular herb in Latino cuisine; however, many farmers in Massachusetts are not familiar with production and postharvest practices for this plant. A factorial experiment was initiated on a commercial farm in eastern Massachusetts to ascertain more information about short-term postharvest treatments. This experiment was performed on three dates in the fall of 1999, which served as replications. There were three main effects: cilantro harvested the same day and stored in the sun, cilantro harvested the same day and stored in the shade, and cilantro harvested on previous day and stored in the shade. For each main effect there were six sub-effects for cilantro storage: roots intact, roots removed, roots intact and plants in sealed plastic bag, roots removed and plants in sealed plastic bag, roots intact and plants in water, roots removed and plants in water. Cilantro bunches were given a visual quality number every hour from 10:30 am to 4:30 pm on each date. No difference in visual quality was observed between cilantro with roots intact compared to cilantro with roots removed. Cilantro stored in the direct sun had a lower visual quality index than cilantro stored in the shade. Cilantro stored in water or in a sealed plastic bag and kept in the shade showed little decrease in visual quality after 7 hours on the day of harvest. The results of these experiments will help farmers in Massachusetts to produce and market cilantro to meet the growing demands for this product.
121 Postharvest Rripening of Tomato Following Low-dose Gamma-irradiation and Water-based Chemical Treatment
Authors: Findley G. , Woods F.M. , Conner D.E. , Mosjidis C. , Weese S.J. , Sundermann C.A. , Wei C.I.
Published: February 2019

Low-dose gamma-irradiation is becoming increasingly an attractive viable technology for control of food-borne pathogens and extension of shelf life of fruits and vegetables. Typically, gamma-irradiation treatment appears to transiently stimulate ethylene synthesis in tomato, which appears to be stress associated, and dose dependent (Larrigaudie et al., 199l). We have investigated the effects of gamma-irradiation treatment at doses of 0, 0.5, 0.75, and 1.0 kGy, alone and in combination with water-based chemical treatment for improving the storage of tomato maintained at 20 °C and 95% RH for 20 days of storage. Changes in ethylene, ascorbic acid and total antioxidant content, color, total soluble solids and carbohydrate concentration were examined. Our preliminary results indicate that these treatments are effective in reducing ethylene concentration in storage while providing a means of eliminating foodborne pathogens without adversely affecting tomato quality.
134 Seasonal Variation in Composition and Total Load of Leaf Blade Epicuticular Waxes on Hosta
Authors: Keith Jessie , Gaston Carole H. , Jenks Matthew A.
Published: February 2019

Hosta variants for epicuticular waxes were selected based on variation in surface glaucousness, from highly glaucous to highly glossy. In an effort to determine seasonal variation in hosta waxes, gas-chromatography mass-spectrometry was used to perform detailed chemical analysis of the adaxial and abaxial leaf blade waxes four times points during the growing season, early spring, mid-spring, mid-summer, and autumn. These studies revealed that in all variants, the total wax loads increased dramatically during the period of leaf expansion in the spring, dropped roughly five fold by midsummer, and then accumulated slightly above summer levels into the fall season. The dominant wax constituent class on all hosta cultivars was primary alcohols. Changes in these alcohols were primarily responsible for seasonal changes in total wax load. In some variants, the shorter chain length alcohols were unusually high compared with alcohol distributions normally found on other plants. Besides primary alcohols, significant amounts of acids, aldehydes, and alkanes, were also found and shown to vary during the growing season. A possible association between these seasonal changes in wax profiles and hosta resistance to slugs is discussed.
141 Salinity Tolerance of Four Turfgrasses
Authors: Alshammary Saad , Qian Y.L. , Wallner S.J.
Published: February 2019

The need for salinity-tolerant turfgrasses is increasing because of increased use of effluent water for turfgrass irrigation. Greenhouse studies were conducted to determine the relative salt tolerance and salt tolerance mechanisms of `Challenger' Kentucky bluegrass (Poa pratensis), `Arid' tall fescue (Festuca arundinacea), `Fults' alkaligrass (Puccinellia distans.), and a saltgrass (Distichlis spicata) collection. Kentucky bluegrass and tall fescue were irrigated with saline solutions at 0.2,1.7, 4.8, or 9.9 dS/m, whereas alkaligrass and saltgrass were irrigated with saline solutions at 0.2, 28.1, 32.8, or 37.5 dS/m prepared using a mixture of NaCl and CaCl2. The salinity levels that caused 50% shoot growth reduction were 9.0, 10.4, 20.0, and 28.5 dS/m for Kentucky bluegrass, tall fescue, saltgrass, and alkaligrass, respectively. Concentrations of proline, a proposed cytoplasmic compatible solute, were 25.8, 30.4, 68.1, and 17.7 μmol/g shoot fw in Kentucky bluegrass, tall Fescue, alkaligrass, and saltgrass, respectively, at the highest salinity level imposed. Bicellular, salt-secreting glands were only observed by scanning electron microscopy on leaves of saltgrass, indicating salt secretion is one of the important salt tolerance mechanisms adopted by saltgrass. Ion contents (Na, Cl, and Ca) in both shoots and roots of all grasses increased with increasing salinity levels. However, alkaligrass maintained a much lower Na, Ca, and Cl contents in roots and shoots than other grasses, suggesting that ion exclusion is one of the major salt tolerance mechanisms in alkaligrass. Tall fescue did not appear to restrict the uptake and translocation of salt in shoot tissues, but maintained a higher K/Na ratio than all other grasses under saline conditions.
151 The Effect of Supro-optimal Temperature on Photosynthesis, Carbohydrate Allocation, Flowering, and Growth of Coreopsis grandiflora `Sunray' AND Gaillardia × grandiflora `Goblin'
Authors: Davis Melyssa K. , Kuehny Jeff S.
Published: February 2019

Coreopsis and Gaillardia were exposed to supra-optimal temperatures of 35 °C for a 6-week period beginning at flower initiation. Photosynthesis measurements were recorded at 1100 hr, 1300 hr, and 1500 hr for 3 days each week and carbohydrate partitioning was determined once per week. Results indicate that the time of day the measurements were taken made little difference on rate of photosynthesis and that there was a similar trend in photosynthetic rate over the 6-week period. Photosynthesis decreased as the plants began to flower and then increased until the onset of flower senescence. The patterns of carbohydrate partitioning were similar to those observed for photosynthesis. The plants grown at supra-optimal and optimal conditions had a similar trend and rate of photosynthesis throughout the 6-week period. Plant growth and total carbohydrates significantly decreased as the duration of high temperature increased for both species, however Gaillardia was more heat tolerant than Coreopsis.
153 Garden Performance of New Guinea Impatiens in Sun and Shade
Authors: Berghage R.D. , Holcomb E.J. , Michael A.H.
Published: February 2019

The New Guinea Impatiens (I. hawkeri Bull.) has become one of the most important spring crops for many growers. Rapid and continuous development of new and improved cultivars have lead to tremendous diversity in flower color, leaf color, plant size, and growth rate. Penn State has conducted large-scale garden evaluations of New Guinea Impatiens since the mid-1990s. Each cultivar is evaluated in both the sun and shade for uniformity, flowering, foliage, and overall growth and form. Ratings use a 1 to 5 scale with 1 being unacceptable, 2 = poor, 3 = fair, 4 = good, and 5 = excellent. Height, width, and flower size are measured in August. One hundred fourteen cultivars in 15 commercial series have been in the trials for two or more seasons. There are significant differences in the performance of cultivars and series in the trials. `Celebrette', `Paradise', `Pure Beauty', `Celebration', and `Riviera' were the top-performing series. Within each series there were outstanding cultivars and others that did not perform as well. Plants performed better in the shade than in the sun. The average rating for plants grown in the sun was 3.3 while the rating for shade grown plants was 3.8. New Guinea impatiens were shorter (11 vs. 12.3 cm), spread less (18.9 vs. 22.1 cm), and had smaller flowers (4.8 vs. 5.3 cm wide) in the sun than in the shade, respectively. There were no significant interactions between sun vs. shade, and cultivar or series.
161 Effects of Light Intensity on Leaf Anatomy of Some Tropical Fruit (Rambutan, Durian, Mangosteen, and Longkong)
Authors: Issarakraisila Montree , Sethpakdee Ravie
Published: February 2019

Leaf anatomy of young rambutan (Nephelium lappaceum Linn.), durian (Durio zibethinus Murray), mangosteen (Garcinia mangostana Linn.), and longkong (Aglaia dookoo Griff.) potted plants grown under different light intensity (100%, 55%, 40%, or 25% of full sun) were observed. The thickness of both palisade and spongy parenchyma decreased as the light intensity decreased. This resulted in a decrease of lamina thickness when the light was lower. An exception occurred in mangosteen when the thickness of both palisade and spongy parenchyma in leaf grown under full sunlight were lower than in leaves grown under 55% or 40% full sun. The thickness ratio of palisade and spongy tissue in rambutan and durian decreased as light intensity decreased. While the ratios in mangosteen and longkong leaves grown under full sunlight were lower than the ratios of leaves grown under 55% or 40% of full sun. The frequency of stomata also decreased as the light intensity decreased. The thickness of palisade tissue of leaves grown under 55% of full sun in rambutan, durian, mangosteen, and longkong were 70, 110, 110, and 55 μm, respectively. The thickness of spongy tissue of leaves grown under 55% of full sun in rambutan, durian, mangosteen, and longkong were 60, 30, 410, and 145 μm, respectively. The thickness of leaves grown under 55% of full sun in rambutan, durian, mangosteen, and longkong were 186, 230, 565, and 233 μm, respectively. The number of stomata per square millimeter of leaves grown under 55% of full sun in rambutan, durian, mangosteen, and longkong were 437, 221, 133, and 301, respectively. Photosynthesis efficiency and light adaptation were discussed.
162 The Influence of Root Restriction on Flowering, Fruiting, Tree Growth, Yields, and Fruit Quality of Apple Trees
Authors: Byers R.E. , Carbaugh D.H. , Combs L.D.
Published: February 2019

`Fuji'/MM.111, `Pink Lady'/M.7A, and `Summerfield'/M.7A apple trees were planted in several types of individual root restrictive bags in the field in 1995. Bags were made of Knit and Woven fabrics, Galvanize hardware cloth (6.4 cm) with various holes sizes and of different bag volumes. The bags confined the development of large roots to within the bag. Roots that penetrated the bag resulted in root branching and large root inhibition. As the roots enlarged, roots penetrating the bags were restricted in diameter by the fabric hole size. Roots enlarged to some degree on both sides of the fabric holes but were not killed by girdling within the first few years. Root restriction bags decreased trunk caliper, shoot growth, pruning weights, number of cuts per tree, increased flowering, fruit numbers, and weight per tree. Fruit firmness, soluble solids and color was increased and starch was lower than the nonbagged controls. In cage and tank trials pine and/or meadow voles easily penetrated all of the fabric and polypropylene bags within 24 h, except for the galvanized hardware cloth (6.4 cm). Susceptibility of each material to vole damage was tested by placement of an apple inside a small bag of each. Root restriction bags seemed to be a viable alternative to dwarfing rootstocks for control of tree size, early flowering, and early fruiting.
168 Weed Suppression and N and P Mineralization in an Orchard Mulched with Composted Poultry Litter
Authors: Preusch P.L. , Tworkoski T.J.
Published: February 2019

Improper management of poultry manure and bedding (litter) can cause hypoxia in aquatic communities, but poultry waste can be converted to a stable organic fertilizer by composting. Peach trees (Prunus persica L. `Sunhigh') received the following treatments in May 1998: commercial fertilizer (15 g N/m2), low-rate composted poultry litter (15 g N/m2 as 2.9 kg composted litter/m2), high-rate composted poultry litter (62 g N/m2 as 11.6 kg composted litter/m2), and no treatment control. Weeds were completely controlled during 1998, but, by Sept. 1999, the high-rate poultry litter had only 27% weed cover compared with 86% for the commercial fertilizer-treated plots. Soil N was highest in plots treated with commercial fertilizer (16.4 mg N-NH4 and 18.6 mg N-NO3 per kg soil, 6 weeks after treatment) and did not differ among the remaining treatments (in the high rate of poultry litter—3.2 mg N-NH4 and 0.7 mg N-NO3 per kg soil, 6 weeks after treatment). Water soluble P in the soil did not differ among treatments at 6 weeks after treatment (≈12 mg P per kg soil for all treatments) but, at 47 weeks after treatment, plots with the high rate of poultry litter had 30 mg P per kg soil compared with 14 mg P per kg soil in plots treated with commercial fertilizer. In general, Mehlich 1 acid-soluble P did not differ among the litter- and fertilizer-treated plots (averaging 45 mg P per kg soil). Acid-soluble P was lowest in control plots (averaging 21 mg P per kg soil). Results indicate that poultry litter could be used as a weed suppressant without adversely affecting nitrogen release to the environment. However, P mineralization may be problematic and requires further investigation.
174 Muskmelon Fruit Soluble Acid Invertase and Sucrose Phosphate Synthase Activity and Polypeptide Profiles during Growth and Maturation
Authors: Lester Gene , Arias Luis Saucedo , Gomez-Lim Miguel
Published: February 2019

Muskmelon [Cucumis melo L. (Reticulatus Group)] fruit sugar content is the single most important consumer preference attribute. During fruit ripening, sucrose accumulates when soluble acid invertase (AI) activity is less then sucrose phosphate synthase (SPS) activity. To genetically heighten fruit sugar content, knowledge of sugar accumulation during fruit development in conjunction with AI and SPS enzyme activities and their peptide immunodetection profiles is needed. Two netted muskmelon cultivars [`Valley Gold' (VG), a high sugar accumulator, and `North Star' (NS), a low sugar accumulator] with similar maturity indices were assayed for fruit sugars, AI, and SPS activity and immunodetection of AI and SPS polypeptides following 2, 5, 10, 15, 20, 25, 30, 35, and 40 (abscission) days after anthesis (DAA). Both cultivars, grown in spring and fall, showed similar total sugar accumulation profiles. Total sugars increased 1.5 fold, from 2 through 5 DAA and then remained unchanged until 30 DAA. From 30 DAA until abscission, total sugar content increased, with VG accumulating significantly more sugar then NS. In both cultivars, during both seasons, sucrose was detected at 2 DAA, which coincided with higher SPS activity than AI activity. At 5 through 25 DAA, SPS activity was less then AI activity resulting in little or no sucrose detection. It was not until 30 DAA that SPS activity was greater than AI activity resulting in increased sucrose accumulation. VG at abscission had higher total sugar content and SPS activity and lower AI activity than NS. Total polypeptides from both cultivars 2 through 40 DAA, were immunodetected with antibodies: anti-AI and anti-SPS. NS had Al isoforms bands at 75, 52, 38, and 25 kDa that generally decreased wtih DAA. One isoform at 52 kDa remained detectable up to anthesis (40 DAA) VG had the same four Al isoforms, all decreased with DAA and became undetectable by 20 DAA. It is unclear if one or all AI isoforms correspond with detected enzyme activity. VG and NS had one SPS band at 58 kDa that increased with DAA and concomitantly with SPS activity. VG had a more intense SPS polypeptide band at abscission then did NS. Thus, netted muskmelon sugar accumulation may be increased by selecting for cultivars with a specific number of AI isoforms, which are down-regulated, and with high SPS activity during fruit ripening.
175 Comparison of Suitability of Nonmelting and Melting Flesh Peach Cultivars for Fresh-cut
Authors: Brecht J.K. , Cordasco K. , Sherman W.B.
Published: February 2019

Two nonmelting flesh (`GUFprince' and `UF2000') and two melting flesh (`Tropic Beauty' and `Rayon') peach cultivars were segregated into ripeness categories at harvest according to initial flesh firmness and prepared as fresh-cut slices as described in Gorny et al. (HortScience 33:110–113), except that there were no “overripe” (0-13 N flesh firmness) stage nonmelting flesh fruit. Slices were stored at 1, 5, or 10 °C for 8 days and were evaluated for visual and taste quality, flesh firmness and color, and respiration and ethylene production rates every other day during storage. The optimal ripeness for preparing fresh-cut slices from the melting flesh cultivars was the “ripe” (13-27 N flesh firmness) stage; less-ripe melting flesh slices did not ripen at 1 or 5 °C and riper melting flesh slices and those held at 10 °C softened excessively, became discolored, and decayed. The optimal ripeness stage for the nonmelting flesh cultivars was 40-53 N flesh firmness, which corresponded to physiologically ripe (climacteric rise) for nonmelting flesh fruit, but melting flesh fruit at that firmenss were physiologically only mature-green (preclimacteric). Storage of nonmelting flesh slices was limited by surface desiccation at 1 °C, and by flesh discoloration at 5 and 10 °C, which was more severe in riper slices. The best storage temperature for both fruit genotypes was 1 °C, which prevented discoloration and decay over the 8-day storage period. Nonmelting flesh peach cultivars are better suited for fresh-cut processing than melting flesh cultivars because their firmer texture allows the use of riper fruit with better flavor than the less ripe fruit that must be used for fresh-cut melting flesh peaches.
179 Impact of Rootstock on Maturity and Storage of Valencia Orange Fruits
Authors: Khattab M.M. , Elezaby A.A. , ElOraby S. , Hassan A.M.
Published: February 2019

This investigation was carried out on 13-year-old Valencia orange trees [Citrus sinensis (L.) Osbeck] budded on five different rootstocks. Heat unit accumulation (temperature above 12.5 °C) for fruits worked on the various rootstocks were calculated from full bloom to maturity stage. Valencia fruits on Troyer citrange (C. sinensis × Poncirus trifoliata) and Carrizo citrange (C. sinensis × Poncirus trifoliata) rootstocks matured earlier when compared to those growing on Cleopatra mandarin (C. reticulata Blanco), Volkamer lemon (C. volkameriana Ten. and Pasq.), and sour orange (C. aurantium) rootstocks. The results showed that the Valencia fruits, regardless of rootstock, could be stored for different periods under different conditions. However, in order to avoid degradation in fruit quality, storing periods should not exceed 21, 60, and 120 days under room conditions (25 °C and RH 25% to 35%), 4 °C (RH 80% to 85%), and 8 °C (RH 80% to 85%); respectively.
183 Stripped Corn Oil Emulsion Alters Ripening, and Reduces Scald and Coreflush in `Granny Smith' Apples, and Scald and Decay in `d'Anjou' Pears
Authors: Ju Zhiguo , Curry Eric A.
Published: February 2019

`Granny Smith' apples (Malus × domestica Borkh) and `d'Anjou' pears (Pyrus communis L.) were dipped in a 2.5%, 5%, or 10% stripped corn oil (α-tocopherol <3 mg·kg-1) emulsions, 2000 mg·L-1 diphenylamine (DPA), respectively, at harvest and stored in air at 0 °C for 8 months. Untreated fruit served as controls. In oil-treated apples and pears, ethylene and α-farnesene production rates were lower in early storage and higher in late storage than in control. Control fruit developed 34% scald in `Granny Smith' apples and 23% scald in `d'Anjou' pears after 6 months storage, whereas fruit treated with oil at 5% or 10%, or with DPA at 2000 mg·L-1 were free from scald. After 8 months storage, oil at 10% was as effective as DPA in controlling scald in pears, whereas in apples, fruit treated with 10% oil developed 18% scald and DPA-treated fruit were scald-free. DPA-treated apples developed 32% senescent scald, while 5% or 10% oil-treated fruit had none. Oil-treated fruit were greener, firmer, and contained more titratable acidity after 8 months of storage than control or DPA-treated apples and pears. In `Granny Smith', 100% of the controls and 79% of the DPA-treated fruit developed coreflush after 8 months of storage, but both 5% and 10% oil-treated fruit were free from coreflush. In `d'Anjou', 34% of the controls and 27% of the DPA-treated fruit showed decay after 8 months of storage, compared with 5% decay in 5% oiltreated fruit, and no decay in 10% oil-treated fruit.
186 Berry Quality and Photosynthate Partitioning in Response to Plant Growth Regulators in Grape
Authors: Yakushiji H. , Morinaga K. , Koshita Y.
Published: February 2019

The effects of 2,3,5-triiodobenzoic acid (TIBA) and naphthaleneacetic acid (NAA) on berry maturation and photoassimilates partitioning were investigated. Five-year-old potted `Kyoho' grape grown under a non-heating glasshouse were used. TIBA (200 mg/L) and NAA (200 mg/L) were applied to clusters at the beginning of veraison (45 days after full bloom). TIBA application increased not only soluble solids concentration in the juice but also anthocyanin content of peel, compared with those of control. On the other hand, the application of NAA reduced berry growth and delayed the berry maturation with harder flesh, lower soluble solids, higher acidity and poor coloration. In order to examine the effect of both plant growth regulators on photoassimilates partitioning in plant tissues, the whole plants were fed with 13CO2 at 10 days and 20 days after application of TIBA and NAA. The 13C distribution of pericarp and peel in NAA application was found on the lowest among the treatments. However, there were no significant differences in the 13C distribution and 13C absorption rate of pericarps between TIBA and control. These results indicate that NAA weakened the sink activity in grape berries, resulted in smaller berry size and the delay of maturation, whereas the berry ripening induced by TIBA application could not be explained by the distribution of photoassimilates in grape berries.
188 Effect of Streptomycin Walnut Blight Sprays on Nut Drop
Authors: Buchner Richard P. , Olson William H , Polito Vito S. , Pinney Katherine
Published: February 2019

Walnut Blight caused by the bacteria Xanthomonas campestris pathovar juglandis is a very destructive disease for California walnut production. Streptomycin is an effective disease control material; however, Streptomycin sprays can result in significant nut drop 3 to 5 weeks after spray application. We investigated the basis for walnut drop following applications of Streptomycin (Agrimycin) for walnut blight control. Flowers and developing nuts were collected from four treatments, plus an unsprayed control. 200 ppm Streptomycim was applied at 1) budbreak; 2) pre, full, and post-bloom; 3) postbloom; 4) budbreak and postbloom; 5) untreated control. Samples were collected regularly beginning at the first budbreak spray and extending through the period of nut drop. Samples were fixed and prepared for histological examination. In treatments with a high incidence of nut drop, the embryo failed to develop. Examination of the stigma and style in flowers from these treatments showed inhibited pollen tube growth. Results indicate that Streptomycin inhibits pollen tube growth, which precludes fertilization. This pattern of development and timing of nut drop following Streptomycin application at full bloom is similar in all ways to unpollinated walnut flowers. Nut growth and development appear normal for 3 to 5 weeks; then nuts abort. If Streptomycin became available for walnut blight control, sprays timed to coincide with pistillate bloom and pistillate flower receptivity should be avoided.