bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution and Transport of Foliar Applied Zinc in Pistachio
Authors: Zhang Qinglong , Brown Patrick H.
Published: January 2019

The distribution and transport of foliar applied Zn were determined for pistachio (Pistachio vera L.) seedlings and mature trees using stable 68Zn isotope. In seedlings, ≈5.4% of Zn adsorbed by the leaf was transported out of the treated leaves and this Zn was detected in all other plant parts to varying extent. In mature trees, the transport of Zn occurred both acropetally and basipetally within the leaflets with more basipetal movement; however, no significant amount of Zn was transported out of the treated leaflets during the first 10 days after application. The total percentage of Zn transported to other plant parts 20 days after application was significantly greater when Zn was applied to immature leaflets (6.5%) than to mature leaflets (2.1%), though the majority of the absorbed Zn remained within the treated leaflets. The limited mobility of foliar-absorbed Zn in pistachio may partially be attributed to the high binding capacity of leaf tissue for Zn.
Apple Fruit Growth and Maturity are Affected by Early Season Temperatures
Authors: Warrington I.J. , Fulton T.A. , Halligan E.A. , de Silva H.N.
Published: January 2019

Container-grown `Delicious', `Golden Delicious', `Braeburn', `Fuji' and `Royal Gala' apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] trees, on Malling 9 (M.9) rootstock, were subjected to a range of different maximum/minimum air temperature regimes for up to 80 days after full bloom (DAFB) in controlled environments to investigate the effects of temperature on fruit expansion, final fruit weight, and fruit maturation. Fruit expansion rates were highly responsive to temperature with those at a mean of 20 °C being ≈10 times greater than those at a mean of 6 °C. All cultivars exhibited the same general response although `Braeburn' consistently showed higher expansion rates at all temperatures compared with lowest rates for `Golden Delicious' and intermediate rates for both `Delicious' and `Fuji'. The duration of cell division, assessed indirectly by measuring expansion rate, appeared to be inversely related to mean temperature (i.e., prolonged under cooler conditions). Subsequently, fruit on trees from the coolest controlled temperature treatment showed greater expansion rates when transferred to the field and smaller differences in fruit size at harvest than would have been expected from the measured expansion rates under the cool treatment. Nonetheless, mean fruit weight from warm postbloom treatments was up to four times greater at harvest maturity than that from cool temperature treatments. Postbloom temperature also markedly affected fruit maturation. Fruit from warm postbloom temperature conditions had a higher soluble solids concentration, more yellow background color, lower flesh firmness, and greater starch hydrolysis than fruit from cooler temperatures.
Development of Chrysanthemum Meristems Grown under Far-red Absorbing Filters and Long or Short Photoperiods
Authors: McMahon Margaret
Published: January 2019

Two chrysanthemum [Dendranthema ×grandiflorum (Ramat) Kitamura] cultivars, `Spears' and `Bright Golden Anne', were grown under artificial short or natural long photoperiod in benchtop chambers covered with clear double-walled acrylic panels (control) or under similar panels filled with CuSO4 (CuSO4*5H2O in solution at 6% w:v) that removed far-red (FR) (700 to 800 nm) light. Three times per week, a tip from one lateral branch from each of three plants per chamber was harvested and the stage of meristem development recorded. The experiment was conducted April through May and repeated May through June. For `Spears' all short photoperiod treatments developed floral primordia at the same time and the rate of development did not differ. All plants in natural photoperiod treatments initiated flower primordia simultaneously with plants in short photoperiod treatments, but development was delayed ≈3 d in the first experiment compared to plants receiving short photoperiods. During the longer photoperiods of the second experiment, plants under FR-absorbing filters and receiving natural photoperiods initiated and developed flowers ≈2 d after plants in short photoperiod treatments initiation and development. Plants under control filters and natural photoperiods had initiation delayed by ≈4 d and development was delayed by ≈11 d. Bud development was normal for all treatments. For `Bright Golden Anne' only short photoperiod treatments developed normal floral primordia. Plants under FR-absorbing filters and exposed to natural photoperiods eventually initiated floral primordia but development was abnormal. No floral primordia developed under natural photoperiod and control filter conditions. The results indicate that if FR-absorbing filters are used to regulate height of chrysanthemum and possibly other photoperiodic plants, the time of flowering may be affected. However, if artificial short photoperiods are imposed with the use of blackout cloth, FR-absorbing filters do not affect flowering response.
Xylem Flow Rate Differences Are Associated with Genetic Variation in Snap Bean Pod Calcium Concentration
Authors: Quintana J.M. , Harrison H.C. , Palta J.P. , Nienhuis J. , Kmiecik K. , Miglioranza E.
Published: January 2019

Two commercial snap bean (Phaseolus vulgaris L.) cultivars (Hystyle and Labrador) that differ in pod Ca concentration were grown aeroponically to assess physiological factors associated with these differences. Xylem flow rate, Ca absorbed, and Ca concentration in sieve sap and pods (all and commercial size no. 4) were measured. Flow rate, Ca absorption and pod Ca concentration, but not sap Ca concentration, differed between cultivars, and this suggests that genetic variability in pod Ca concentration is caused mainly by differences in flow rate, rather than differences in sap Ca concentration. `Hystyle' showed 1.6 times greater flow rate, 1.5 times greater pod Ca concentration, and 1.7 times greater Ca absorbed than `Labrador'. Flow rate correlated positively with Ca absorbed (R = 0.90), Ca concentration in pods of size no. 4 (R = 0.55), and total pods (R = 0.65). Plant maturity influenced sap Ca concentration and Ca translocated increased as plant matured. These results provide evidence that flow rate differences may cause variability for pod Ca concentration in snap beans.
Ion Accumulation and Distribution in Shoot Components of Salt-stressed Eucalyptus Clones
Authors: Grieve C.M. , Shannon M.C.
Published: January 2019

Four clones of Eucalyptus camaldulensis Dehn. (4543, 4544, 4573, and 4590) and one clone of E. rudis Endl. (4501) were grown in greenhouse sand cultures irrigated with waters designed to simulate saline drainage waters present in the San Joaquin Valley of California, and compositions that would result from further concentration of the waters. The drainage waters are typically high in Na+, SO42-, Cl-, and Mg2+. Electrical conductivities of the solutions were 2, 12, and 28 dS·m-1. Ion uptake and distribution patterns in above-ground components were studied in members of these clones grown under treatment for 7 weeks. Results indicated the clones could be separated into two distinct groups by significant differences in leaf-ion relations. Group 1 clones 4543, 4544, and 4573 accumulated less Na+ and more Ca2+ and Cl- in leaves than group 2 clones, 4501 and 4590. Group 2 clones accumulated Na+ under low salinity, but apparently possessed some mechanism for restricting Na+ accumulation by the leaves that was activated as salinity increased. Leaf and stem Cl- concentrations tended to be lower in all clones grown at 28 dS·m-1 than at 2 dS·m-1, despite increases in Cl- concentration in the irrigation waters. Under saline conditions, K+ and P were preferentially accumulated in the youngest leaves in the upper portion of the canopy, whereas Na+, Ca2+, and Mg2+ were retained in the older leaves.
Transformation of `Beurre Bosc' Pear with the rolC Gene
Authors: Bell Richard L. , Scorza Ralph , Srinivasan Chinnathambi , Webb Kevin
Published: January 2019

`Beurre Bosc' pear (Pyrus communis L.) was transformed with Agrobacterium tumefaciens (E.F. Smith & Townsend) Conn strain EHA101 containing the binary vector pGA-GUSGF into which the rolC gene had been inserted. Leaf explants from in vitro shoot tip cultures were wounded, Agrobacterium-inoculated, and cultured on kanamycin selection medium. Regenerating shoots were transferred to proliferation medium without antibiotics. Three clones tested positive for GUS and nptII enzyme activity. Transformation with the rolC gene was confirmed by DNA, RNA, and protein blot analyses. The number of copies of the rolC transgene varied from one to three. Plantlets of the three transgenic clones were acclimated and transferred to the greenhouse. Preliminary observations of phenotype indicate that the rolC gene reduced height, number of nodes, and leaf area of transgenic `Beurre Bosc'.
Molecular Mapping of Disease Resistance Genes for Halo Blight, Common Bacterial Blight, and Bean Common Mosaic Virus in a Segregating Population of Common Bean
Authors: Ariyarathne H.M. , Coyne D.P. , Jung G. , Skroch P.W. , Vidaver A.K. , Steadman J.R. , Miklas P.N. , Bassett M.J.
Published: January 2019

Diseases of beans (Phaseolus vulgaris L.) are primary constraints affecting bean production. Information on tagging and mapping of genes for disease resistance is expected to be useful to breeders. The objectives of this study were to develop a random amplified polymorphic DNA (RAPD) marker linkage map using 78 F9 recombinant inbred (RI) lines derived from a Middle-American common bean cross Great Northern Belneb RR-1 [resistant to common bacterial blight (CBB) and halo blight (HB)] × black A 55 [dominant I gene resistance to bean common mosaic potyvirus] and to map genes or QTL (quantitative trait loci) for resistance to CBB, HB, BCMV (bean common mosaic virus), and BCMNV (bean common mosaic necrosis virus) diseases. The RI lines were evaluated for resistance to leaf and pod reactions to Xanthomonas campestris pv. phaseoli (Xcp) (Smith Dye) strain EK-11, leaf reactions to two Pseudomonas syringae pv. phaseolicola (Psp) (Burkholder) Young et al. (1978) strains HB16 and 83-Sc2A, and BCMV strain US-5 and BCMNV strain NL-3. The linkage map spanned 755 cM, including 90 markers consisting of 87 RAPD markers, one sequence characterized amplified region (SCAR), the I gene, and a gene for hypersensitive resistance to HB 83-Sc2A. These were grouped into 11 linkage groups (LG) corresponding to the 11 linkage groups in the common bean integrated genetic map. A major gene and QTL for leaf resistance to HB were mapped for the first time. Three QTL for leaf reactions to HB16 were found on linkage groups 3, 5, and 10. Four regions on linkage groups 2, 4, 5, and 9, were significantly associated with leaf reactions to HB strain 83-Sc2A. The gene controlling the hypersensitive reaction to HB 83-Sc2A mapped to the same region as the QTL on LG 4. The I locus for resistance to BCMV and BCMNV was mapped to LG 2 at about 1.4 cM from RAPD marker A10.1750. Five and four markers were significantly associated with QTL for resistance to CBB in leaves and pods, respectively, with four of them associated with resistance in both plant organs. A marker locus was discovered on LG 10, W10.550, which could account for 44% and 41% of the phenotypic variation for CBB resistance in leaves and pods, respectively. QTL for resistance in pod to CBB, leaf resistance to HB, and the I gene were linked on LG 2.
Long-term Effects of Restricted Root Volume and Regulated Deficit Irrigation on Peach: II. Productivity and Water Use
Authors: Boland A.M. , Jerie P.H. , Mitchell P.D. , Goodwin I. , Connor D.J.
Published: January 2019

Individual and interactive effects of restricted root volume (RRV) and regulated deficit irrigation (RDI) on productivity and water use of peach trees [Prunus persica (L.) Batsch `Golden Queen'] were studied over 3 years (1992-95). Trees were grown in lysimeters of five different soil volumes (0.025, 0.06, 0.15, 0.4, and 1.0 m3) with either full or deficit (RDI) irrigation. In Years 3 and 4, fruit size was reduced by up to 30% on trees in the two smallest volumes. Tree water use was positively related to increasing soil volume (linear, P < 0.001; quadratic, P < 0.011) in all years ranging from 1.8 to 4.4 L·mm-1 Epan in the post-RDI period of Year 2. Water use of deficit-irrigated trees was less than fully irrigated trees and there was an interaction between soil volume and irrigation treatment during RDI. Water relations did not limit growth or productivity. Tree water use was reduced under root restriction as a consequence of canopy demand rather than leaf function. Results suggest that a combination of restricted root volume and development of water stress achieve the RDI response in the Goulburn Valley, Australia.
Diversity and Distribution of Isozymes in a Schlumbergera (Cactaceae) Clonal Germplasm Collection
Authors: O'Leary Maureen C. , Boyle Thomas H.
Published: January 2019

A germplasm collection of 59 Schlumbergera Lemaire clones was assayed for isozymes of aspartate aminotransferase, glucose-6-phosphate isomerase, leucine aminopeptidase, malate dehydrogenase, phosphoglucomutase, shikimate dehydrogenase, and triosephosphate isomerase. The collection included cultivars of holiday cactus [S. truncata (Haworth) Moran and S. ×buckleyi (T. Moore) Tjaden] plus accessions of S. kautskyi (Horobin & McMillan) N.P. Taylor, S. opuntioides (Löfgren & Dusén) D. Hunt, S. orssichiana Barthlott & McMillan, S. russelliana (Hooker) Britton & Rose, S. ×exotica Barthlott & Rauh, and S. ×reginae McMillan & Orssich. Twelve loci with 36 alleles were detected. Percent polymorphic loci, mean number of alleles per locus, and mean heterozygosity were 83, 3.00, and 0.24, respectively, for the entire collection. Forty-one clones (69%) could be distinguished solely on the basis of their isozyme profiles, but the remaining 18 clones shared profiles with one or two other clones. Isozymes proved useful for determining the parentage of some clones and verifying that some progeny were interspecific hybrids. About 28% of the genetic diversity within the entire collection is unique to four Schlumbergera species that have scarcely been exploited for breeding holiday cactus cultivars.
Amplified Fragment Length Polymorphism Analysis for Studying Genetic Relationships among Mangifera Species in Thailand
Authors: Eiadthong Wichan , Yonemori Keizo , Kanzaki Shinya , Sugiura Akira , Utsunomiya Naoki , Subhadrabandhu Suranant
Published: January 2019

The phylogenetic relationships among 14 Mangifera L. species including three economically important species, i.e., common mango (M. indica L.), horse mango (M. foetida Lour.) and kwini (M. odorata Griff.), were analyzed by comparing 217 amplified fragment length polymorphism (AFLP) markers. The unweighted pair grouping method using arithmetic averages (UPGMA) and neighbor-joining (NJ) method were used and two outgroup taxa, cashew nut (Anacardium occidentale L.) and gandaria (Bouea macrophylla Griff.), were added to both analyses. The common mango was closely related to banana mango (M. sylvatica Roxb.), M. laurina Bl., and M. oblongifolia Hook.f. Intraspecific variation among seven cultivars of common mango was much smaller than interspecific variation and these cultivars were classified into one M. indica group using both methods. Mangifera macrocarpa Bl., M. foetida, and M. odorata were also related to M. indica in both UPGMA and NJ trees, although these three species are classified into a different subgenus (subgenus Limus) from the subgenus Mangifera to which M. indica belongs. Also, in both UPGMA and NJ trees, M. gedebe Miq. and M. griffithii Hk.f. were placed in distant positions among the Mangifera species tested, indicating these two species are related distantly to M. indica. The AFLP technique was confirmed to be useful for phylogenetic analysis.
Capacity of Broccoli to Induce a Mammalian Chemoprotective Enzyme Varies among Inbred Lines
Authors: Farnham Mark W. , Stephenson Katherine K. , Fahey Jed W.
Published: January 2019

Broccoli (Brassica oleracea L., Italica Group) has been recognized as a source of glucosinolates and their isothiocyanate metabolites that may be chemoprotective against human cancer. A predominant glucosinolate of broccoli is glucoraphanin and its cognate isothiocyanate is sulforaphane. Sulforaphane has been shown to be a potent inducer of mammalian detoxication (Phase 2) enzyme activity and to inhibit chemical-induced tumorigenesis in animal models. Little is known about phenotypic variation in broccoli germplasm for Phase 2 enzyme (e.g., quinone reductase) induction potential. Thus, this study was undertaken to evaluate: 1) quinone reductase induction potential (QRIP) diversity among a population of broccoli inbreds; 2) QRIP levels in selected lines; 3) correlation of QRIP with other horticultural characteristics; and 4) QRIP expression in a sample of synthesized hybrids. In 1996, 71 inbreds and five hybrid checks (all field-grown), ranged from a QRIP of nearly zero to 150,000 units/g fresh weight (FW) (mean of 34,020 units/g FW). These values were highly correlated with methylsulphinylalkyl glucosinolate (MSAG; primarily glucoraphanin) concentrations that ranged from 0.04 to 2.94 μmol.g-1 FW. A select subset of lines evaluated in 1996 were reevaluated in 1997. QRIP and MSAG values in this second year were similar to and correlated with those observed in 1996 (r = 0.73, P < 0.0001 and r = 0.79, P < 0.0001, respectively). In addition, both QRIP and MSAG concentration were highly correlated with days from transplant to harvest. Average F1 hybrid values for QRIP and MSAG in 1997 fell typically between their parental means, but were often closer to the mean of the low parent. Results of this study indicate that divergent QRIP expression can effectively be used to select enhanced inbred lines to use in development of value-added hybrids. Evidence is also provided that there is a significant genetic component to both QRIP and MSAG concentration, and that selection for either one may provide an effective means for developing broccoli hybrids with enhanced chemoprotective attributes. Chemical names used: 4-methylsulphinylbutyl glucosinolate (glucoraphanin) and 4-methylsulphinylbutyl isothiocyanate (sulforaphane).
Floral Biology and Seed Production in Cultivated North American Ginseng (Panax quinquefolius)
Authors: Schluter Cayetana , Punja Zamir K.
Published: January 2019

Morphological characteristics of flowers, duration of flowering, degree of self-pollination, and extent of berry and seed production in North American ginseng (Panax quinquefolius L.) were studied under controlled environmental conditions as well as under field conditions. A comparison was also made between plants of 3 and 4 years of age at two field locations. The duration of flowering was ≈4 weeks and was similar in plants of both age groups grown in the two environments; however, 4-year-old plants produced an average of 40% more flowers (≈100 per plant in total) compared to 3-year-old plants. Flowers were comprised of five greenish-colored petals, five stamens, and an inferior ovary consisting of predominantly two fused carpels and stigmatic lobes. Anthers dehisced in staggered succession within individual flowers, and flowering began with the outermost edge of the umbel and proceeded inwards. At any given time during the 4-week flowering period, ≈10% of the flowers in an umbel had recently opened and were producing pollen. Stigma receptivity was associated with separation of the stigmatic lobes; this occurred at some time after pollen release. Growth of pollen tubes through the style in naturally pollinated flowers was most evident when the stigmatic lobes had separated. The proportion of flowers that developed into mature berries (pollination success rate) was in the range of 41% to 68% for both 3-year-old and 4-year-old plants. However, when the inflorescence was bagged during the flowering period, berry formation was increased by 13% to 21% in 4-year-old plants, depending on location. A majority of the berries (92% to 99%) contained one or two seeds in an almost equal frequency, with the remaining berries containing three seeds. In 4-year-old plants, the frequency of two-seeded berries was increased by ≈13% by bagging the inflorescence. These observations indicate that P. quinquefolius is highly self-fertile and that several physiological and environmental factors can affect seed production.
Inheritance of Resistance to the Peanut Root-knot Nematode in Capsicum chinense
Authors: Fery Richard L. , Thies Judy A.
Published: January 2019

Greenhouse experiments determined the inheritance of resistance to the peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1] in Capsicum chinense Jacq. germplasm lines PA-353 and PA-426. Evaluation of parental, F1, F2, and backcross populations of the crosses PA-353 × PA-350 and PA-426 × PA-350 (PA-350 is a susceptible cultigen) indicated that resistance in both C. chinense germplasm lines was conditioned by a single dominant gene. Evaluation of the F1 × resistant parent backcross populations in the cytoplasm of their respective resistant and susceptible parents indicated that the cytoplasm of the resistant parent is not needed for full expression of resistance. Allelism tests indicated that the dominant resistance gene in both PA-353 and PA-426 is allelic to a resistance gene in C. annuum L. `Carolina Cayenne'. However, these allelism tests did not demonstrate conclusively that the M. arenaria race 1 resistance gene in C. chinense is the N gene that conditions resistance to the southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] in C. annuum. The ease and reliability of evaluating plants for resistance to root-knot nematodes and the availability of simply inherited sources of resistance makes breeding for peanut root-knot nematode resistance a viable objective in C. chinense breeding programs.
Growth Respiration, Maintenance Respiration, and Carbon Fixation of Vinca: A Time Series Analysis
Authors: van Iersel Marc W. , Seymour Lynne
Published: January 2019

Respiration is important in the overall carbon balance of plants, and can be separated into growth (Rg) and maintenance respiration (Rm). Estimation of Rg and Rm throughout plant development is difficult with traditional approaches. Here, we describe a new method to determine ontogenic changes in Rg and Rm. The CO2 exchange rate of groups of 28 `Cooler Peppermint' vinca plants [Catharanthus roseus (L.) G. Don.] was measured at 20 min intervals for 2 weeks. These data were used to calculate daily carbon gain (DCG, a measure of growth rate) and cumulative carbon gain (CCG, a measure of plant size). Growth and maintenance respiration were estimated based on the assumption that they are functions of DCG and CCG, respectively. Results suggested a linear relationship between DCG and Rg. Initially, Rm was three times larger than Rg, but they were similar at the end of the experiment. The decrease in the fraction of total available carbohydrates that was used for Rm resulted in an increase in carbon use efficiency from 0.51 to 0.67 mol·mol-1 during the 2-week period. The glucose requirement of the plants was determined from Rg, DCG, and the carbon fraction of the plant material and estimated to be 1.39 g·g-1, while the maintenance coefficient was estimated to be 0.031 g·g-1·d-1 at the end of the experiment. These results are similar to values reported previously for other species. This suggests that the use of semicontinuous CO2 exchange measurements for estimating Rg and Rm yields reasonable results.
RolC-Transgenic Carnation with Improved Horticultural Traits: Quantitative and Qualitative Analyses of Greenhouse-grown Plants
Authors: Zuker Amir , Tzfira Tzvi , Scovel Gideon , Ovadis Marianna , Shklarman Elena , Itzhaki Hanan , Vainstein Alexander
Published: January 2019

Expression of the rolC gene under the constitutive CaMV 35S promoter led to several advantageous alterations in transgenic carnation (Dianthus caryophyllus L. `White Sim'). The rolC-transgenic carnation plants exhibited increased axillary budbreak and development when grown under standard commercial greenhouse conditions. Carnation with rolC generated up to 48% more stem cuttings per mother plant than nontransformed plants. Stem cuttings from rolC plants exhibited better rooting ability, with up to five times higher root dry weight than controls. The improved rooting of rolC-transgenic stem cuttings was also apparent when the cuttings were treated with IBA. During the flowering season, rolC-transgenic plants produced up to three times more flowering stems than control plants. It should be noted that the latter alterations, namely increased flowering and rooting, are of major importance to the carnation industry. Chemical name used: indole-3-butyric acid (IBA).
Postproduction of Potted Miniature Rose: Flower Respiration and Single Flower Longevity
Authors: Monteiro José A. , Nell Terril A. , Barrett James E.
Published: January 2019

Research was conducted to investigate the relationship between flower respiration and flower longevity as well as to assess the possibility of using miniature rose (Rosa hybrida L.) flower respiration as an indicator of potential flower longevity. Using several miniature rose cultivars as a source of variation, four experiments were conducted throughout the year to study flower respiration and flower longevity under interior conditions. For plants under greenhouse as well as interior conditions, flower respiration was assessed on one flower per plant, from end-of-production (sepals beginning to separate) up to 8 days after anthesis. Interior conditions were 21 ± 1 °C and 50 ± 5% relative humidity with a 12-hour photoperiod of 12 μmol·m-2·s-1 (photosynthetically active radiation). Flower respiration was higher if the plants were produced during spring/summer as compared to fall/winter. `Meidanclar', `Schobitet', and `Meilarco' miniature roses had higher flower respiration rates than `Meijikatar' and `Meirutral'. These two cultivars with the lowest respiration rates showed much greater flower longevity if grown during spring/summer as compared to fall/winter. The three cultivars with the higher respiration rates did not show differences in flower longevity between seasons. For plants under greenhouse or interior conditions, flower respiration was negatively correlated with longevity in spring/summer but a positive correlation between these parameters was found in fall/winter. During spring/summer, flower respiration rate appears to be a good indicator of potential metabolic rate, and flowers with low respiration rates last longer.
Modification of Plant Architecture in Chrysanthemum by Ectopic Expression of the Tobacco Phytochrome B1 Gene
Authors: Zheng Zhi-Liang , Yang Zhenbiao , Jang Jyan-Chyan , Metzger James D.
Published: January 2019

Height control is a major consideration during commercial production of chrysanthemum [Dendranthema×grandiflora Kitam. (syn. Chrysanthemum×morifolium Ramat.)]. We have addressed this problem by a biotechnological approach. Plants of `Iridon' chrysanthemum were genetically engineered to ectopically express a tobacco (Nicotiana tabacum L.) phytochrome B1 gene under the control of the CaMV 35S promoter. The transgenic plants were shorter in stature and had larger branch angles than wild type (WT) plants. Reduction in growth caused by the ectopic expression of the tobacco phytochrome B1 gene was similar to that caused using a commercial growth retardant at the recommended rate. Another morphological effect observed in the leaves of the transgenic plants was more intense green color that was related to higher levels of chlorophyll. The transgenic plants appeared very similar to WT plants grown under a filter that selectively attenuated far red wavelengths. Furthermore, when plants were treated either with gibberellin A3 (which promoted growth) or 2-chlorocholine chloride, an inhibitor of gibberellin biosynthesis (which inhibited growth) the difference in the average internode length between the transgenic plants and WT plants was the same in absolute terms. This suggests that reduction of growth by the expressed PHY-B1 transgene did not directly involve gibberellin biosynthesis. The commercial application of this biotechnology could provide an economic alternative to the use of chemical growth regulators, thereby reducing production costs.
Identification of Molecular Markers Linked to the Trait of Natural Astringency Loss of Japanese Persimmon (Diospyros kaki) Fruit
Authors: Kanzaki Shinya , Yonemori Keizo , Sugiura Akira , Sato Akihiko , Yamada Masahiko
Published: January 2019

Japanese persimmon (Diospyros kaki Thunb.) cultivars are classified into four types depending upon the nature of astringency loss of the fruit. Among them, the pollination-constant and nonastringent (PCNA) type is the most desirable for fresh fruit consumption due to the trait of stable loss of astringency on the tree with fruit development. Lack of tannin accumulation is the main cause of natural astringency loss in PCNA-type fruit, and is qualitatively inherited. The PCNA trait is recessive to the non-PCNA trait. In this study, we investigated amplified fragment length polymorphism (AFLP) markers for the trait of natural astringency loss of PCNA-type fruit using bulked segregant analysis (BSA) for efficient selection of PCNA type plants in a breeding population. A total of 128 primer combinations were tested and one AFLP marker was found to be linked to the dominant allele controlling the trait for astringency. This marker, EACC/MCTA-400, was absent in all of the PCNA-type plants tested, whereas it was present in about half of the non-PCNA-type plants tested. However, RFLP analysis using this marker enabled the detection of the other dominant allele, and all PCNA-type plants could be distinguished from the non-PCNA-type plants. Application of this marker system will be useful for the selection of PCNA-type plants in persimmon breeding.
Particle Film Application Influences Apple Leaf Physiology, Fruit Yield, and Fruit Quality
Authors: Glenn D. Michael , Puterka Gary J. , Drake Stephen R. , Unruh Thomas R. , Knight Allen L. , Baherle Pedro , Prado Ernesto , Baugher Tara A.
Published: January 2019

Particle film technology is a developing pest control system for tree fruit production systems. Trials were performed in Santiago, Chile, and York Springs, Pa., Wenatchee and Yakima, Wash., and Kearneysville, W. Va., to evaluate the effect of particle treatments on apple [Malus sylvestris (L.) Mill. var. domestica (Borkh) Manst.] leaf physiology, fruit yield, and fruit quality. Leaf carbon assimilation was increased and canopy temperatures were reduced by particle treatments in seven of the eight trials. Yield and/or fruit weight was increased by the particle treatments in seven of the eight trials. In Santiago and Kearneysville, a* values of the fruit surface were more positive in all trials although a* values were not increased in Wenatchee and Yakima. Results indicate that particle film technology is an effective tool in reducing heat stress in apple trees that may result in increased yield potential and quality.
Genetic Analysis of Cut-flower Longevity in Antirrhinum majus
Authors: Schroeder Kenneth R. , Stimart Dennis P.
Published: January 2019

Genetics of Antirrhinum majus L. (snapdragon) cut flower postharvest longevity (PHL) was investigated by generation means analysis using a white short-lived inbred (WS) and white long-lived inbred (WL) to determine mode of inheritance and heritability. Broad and narrow sense PHL heritability was estimated at 78% and 30%, respectively. Scaling tests for adequacy of an additive-dominance model in explaining PHL inheritance suggested absence of epistasis. However, joint scaling indicated digenic or higher order epistatic interactions. Fitting of a digenic epistatic model revealed significant additive effects and nonsignificant dominance and epistatic interactions. Additionally, based on sequential model fittings all six parameters [mean, additive (a), dominance (d), a×a, d×d, and a×d] proved necessary to explain observed PHL variation. Continuous variation for PHL observed in the F2 and backcross generations suggests PHL is quantitative. Assessment of associated traits revealed a positive relationship between number of flowers opening postharvest on a cut flower and PHL. In addition, floret wilting led to short PHL while floret browning was associated with long PHL.
Chloroplast and Nuclear Genome Analysis of the Parentage of Lemons
Authors: Gulsen O. , Roose M.L.
Published: January 2019

Chloroplast DNA (cpDNA) restriction fragment length polymorphisms were used to study the parentage of lemons [Citrus limon (L.) Burm. f.] and several other putative hybrids. The 30 citrus accessions studied included nine lemons, three pummelos [C. maxima (Burm.) Merrill], three citrons (C. medica L.), three mandarins (C. reticulata Blanco, C. clementina Hort. Ex. Y. Tan., and C. sunki Hort. ex. Tan.), and single representatives of 13 other taxa. Four different fragments of citrus cpDNA were amplified by polymerase chain reaction using four universal chloroplast primers and amplification products were digested with four endonucleases, Rsa I, Dra I, Hae III, and Mbo I. A total of 104 different restriction fragments were scored and used for phylogenetic analysis by parsimony. The three taxa which have been proposed as ancestral Citrus L. sp., C. medica, C. maxima, and C. reticulata, had distinct cpDNA patterns. Pummelo contributed the chloroplast genome to lemons, sweet orange [C. sinensis (L.) Osbeck], and Bergamot orange (C. bergamia Risso and Poit.), and mandarin contributed the chloroplast genome to rough lemons (C. jambhiri Lush.), Rangpur lime (C. limonia Osbeck), and `Mexican' lime [C. aurantifolia (Christm.) Swing.]. Data suggest that the particular accessions of these ancestral species that were studied were not directly involved in the hybridization events that created these hybrids, since they have similar but not identical cpDNA restriction fragments. Using inter-simple sequence repeat markers that amplified from nuclear genomic DNA, a set of samples including pummelos, citrons, mandarins, sour oranges (C. aurantium L.), and `Samuyao' papeda (C. micrantha Wester) were tested as possible parents of lemons. Sour orange and citron together had all nuclear and chloroplast fragments found in lemon and are therefore proposed to be the maternal and paternal parents, respectively, of many commercial lemon cultivars, including `Lisbon', `Eureka', `Villafranca', and `Monachello'.
Identification of Genetic Markers in Olive Linked to Olive Leaf Spot Resistance and Susceptibility
Authors: Mekuria Genet Teshome , Collins Graham , Sedgley Margaret , Lavee Shimon
Published: January 2019

Olive leaf spot is a disease of olive (Olea europaea L.) caused by the fungal pathogen, Spilocea oleaginea Cast. Progeny derived from crosses among susceptible, resistant, and semiresistant parental lines were assessed in the field for 8 years and classified as either resistant or susceptible. DNA from some of the progeny of this segregating population was used to identify molecular markers linked to olive leaf spot disease using the randomly amplified polymorphic DNA (RAPD) technique and bulked segregant analysis (BSA). Two DNA bulks were constructed, each containing 13 progeny showing either resistance or susceptibility for the disease, and screened for polymorphisms using 100 primers. One primer produced two polymorphic bands, one of ≈700 base pairs (bp) from the susceptible bulk and the other of ≈780 bp from the resistant bulk. The 780 bp marker appeared in 70.6% of the segregating progeny and 100% of parents showing resistance to leaf spot disease, while the 700 bp marker appeared in 47.1% of the segregating progeny and 100% of the parents showing susceptibility. These markers can be used as screening tools in olive improvement programs.
Lemons: Diversity and Relationships with Selected Citrus Genotypes as Measured with Nuclear Genome Markers
Authors: Gulsen O. , Roose M.L.
Published: January 2019

Inter-simple sequence repeats (ISSR), simple sequence repeats (SSR) and isozymes were used to measure genetic diversity and phylogenetic relationships among 95 Citrus L. accessions including 57 lemons [C. limon (L.) Burm. f.], related taxa, and three proposed ancestral species, C. maxima (Burm.) Merrill (pummelo), C. medica L. (citron), and C. reticulata Blanco (mandarin). The ancestry of lemons and several other suspected hybrids was also studied. Five isozyme and five SSR loci revealed relatively little variation among most lemons, but a high level of variation among the relatively distant Citrus taxa. Eight ISSR primers amplified a total of 103 polymorphic fragments among the 83 accessions. Similarity matrices were calculated and phylogenetic trees derived using unweighted pair-group method, arithmetic average cluster analysis. All lemons, rough lemons, and sweet lemons, as well as some other suspected hybrids, clustered with citrons. Most lemons (68%) had nearly identical marker phenotypes, suggesting they originated from a single clonal parent via a series of mutations. Citrons contributed the largest part of the lemon genome and a major part of the genomes of rough lemons, sweet lemons, and sweet limes. Bands that characterize C. reticulata and C. maxima were detected in lemons, suggesting that these taxa also contributed to the pedigree of lemon.
ISSR Analysis of Cultivars of Pear and Suitability of Molecular Markers for Clone Discrimination
Authors: Monte-Corvo Luisa , Goulão Luis , Oliveira Cristina
Published: January 2019

Inter-simple sequence repeat (ISSR) markers were used for cultivar identification and for determination of the phenetic relationships among 24 pear cultivars (Pyrus communis L.). The ability of several molecular marker systems including randomly amplified polymorphic DNA (RAPD), amplified fragment length polymorphisms (AFLP), inter-simple sequence repeats (ISSR), simple sequence repeats (SSR), and selective amplification of microsatellite polymorphic loci (SAMPL) to detect variation among clones of the most significant Portuguese cultivar, Rocha, was also investigated. Each of the eight ISSR primers tested was able to distinguish the 24 pear cultivars. The ISSR primers generated 337 markers, 79.5% of which were polymorphic. The cultivar dendrogram obtained with the ISSR marker data was very similar to that obtained with previous RAPD+AFLP analysis, confirming the genetic divergence of `Pérola', `Carvalhal' and `Lawson' from the other cultivars. Eight out of 15 apple [Malus sylvestris (L.) Mill. var domestica (Borkh.) Mansf.] SSR primers tested also amplified microsatellites in pear. None of the five molecular marker systems analyzed (with a total of 1082 markers) detected reproducible polymorphisms among the nine `Rocha' clones, in spite of the presence of clear phenotypic differences.
Developmental Anatomy of Zucchini Leaves with Squash Silverleaf Disorder caused by the Silverleaf Whitefly
Authors: Schmalstig Judy G. , McAuslane Heather J.
Published: January 2019

Squash silverleaf (SSL) is a physiological disorder of vegetables in the genus Cucurbita L. caused by feeding of nymphs of the silverleaf whitefly (SLW) (Bemisia argentifolii Bellows & Perring). SSL causes a silvering of the leaves and a blanching of fruit. Leaf silvering is caused by developmental separation of the upper epidermis and the palisade mesophyll layer resulting in additional air space and altered light reflection. The anatomical development of SSL was analyzed in young leaves of zucchini squash (Cucurbita pepo L.) using two susceptible genotypes (`Elite' and YSN347-PMR) and two tolerant genotypes (ZUC76-SLR and ZUC33-SLR/PMR). SLW nymphs were allowed to feed only on the mature leaves and the anatomy of the developing leaves was observed by light microscopy and transmission electron microscopy. Silvering began at the apex of young leaves and developed basipetally. The increased percentage of air space that resulted between the upper epidermis and palisade layers was the result of an increase in the duration of air space development in young, developing leaves. Chloroplasts in silvered tissue of mature leaves and in tissue of young leaves that later became silvered, were smaller and contained less starch than chloroplasts in tissue from noninfested plants. In contrast, development of genetic silvering, a condition not related to whitefly feeding, occurred throughout the entire leaf at one time, beginning as yellowed tissue in the axils of leaf veins then turning silver. Chloroplasts were normal in genetically silvered tissue of genotype YSN421-PMR. The SSL-tolerant genotype, ZUC76-SLR, did not show alteration in chloroplast structure or air space development when challenged with SLW; however, it had shorter and paler petioles, as did the susceptible genotypes. SSL symptoms were induced with spraying of gibberellic acid synthesis inhibitor chlormequat chloride in SSL-susceptible but not in SSL-tolerant genotypes. Reciprocal grafting between susceptible and tolerant plants showed that tolerance resides in the developing tissue and not the mature tissue on which the whiteflies feed.
Nitrite Concentration Effects on NO3-N Uptake and Reduction, Growth, and Fruit Yield in Strawberry
Authors: Darnell Rebecca L. , Stutte Gary W.
Published: January 2019

Strawberries (Fragaria xananassa Duch. .Osogrande.) were grown hydroponically with three NO3-N concentrations (3.75, 7.5, or 15.0 mM) to determine effects of varying concentration on NO3-N uptake and reduction rates, and to relate these processes to growth and fruit yield. Plants were grown for 32 weeks, and NO3-N uptake and nitrate reductase (NR) activities in roots and shoots were measured during vegetative and reproductive growth. In general, NO3-N uptake rates increased as NO3-N concentration in the hydroponics system increased. Tissue NO3-. concentration also increased as external NO3-N concentration increased, reflecting the differences in uptake rates. There was no effect of external NO3-N concentration on NR activities in leaves or roots during either stage of development. Leaf NR activity averaged ~360 nmol NO2 formed/g fresh weight (FW)/h over both developmental stages, while NR activity in roots was much lower, averaging ~115 nmol NO2 formed/g FW/h. Vegetative organ FW, dry weight (DW), and total fruit yield were unaffected by NO3-N concentration. These data suggest that the inability of strawberry to increase growth and fruit yield in response to increasing NO3-N concentrations is not due to limitations in NO3-N uptake rates, but rather to limitations in NO3 - reduction and/or assimilation in both roots and leaves.
Environmental Control of Moisture Content and Viability in Schlumbergera truncata (Cactaceae) Pollen
Authors: Boyle Thomas H.
Published: January 2019

The objective of this study was to determine the effects of temperature, relative humidity (RH), and storage duration on moisture content and viability of Schlumbergera truncata (Haworth) Moran (Thanksgiving cactus) pollen. Pollen viability was assayed by the fluorochromatic reaction (FCR) test, percentage fruit set, and numbers of viable seeds per fruit. Pollen moisture content was ≈38% at anthesis but decreased to ≈12% by 1 day after anthesis and remained low (10% to 12%) until flowers senesced. Pollen viability was 85% on the day of anthesis, remained at ≈80% from 1 to 3 days after anthesis, and decreased to ≈65% when flowers began to senesce. When pollen was stored for 4 days at 21 °C, moisture content decreased to 1% for pollen stored at 1% RH but increased to 33% for pollen kept at 100% RH. Fruit and seed yields obtained with pollen stored for 4 days at 21 °C and 15%, 28%, or 52% RH did not differ significantly from those obtained with fresh pollen. Pollen stored for 4 days at 21 °C and 1%, 68%, or 90% RH produced fewer fruit and seeds than fresh pollen. Fruit and seed yields obtained with pollen stored 20 days at 21 °C and 15% or 28% RH were similar to yields obtained with fresh pollen. Pollen with ≤23% moisture content that was stored at -18 °C for ≥24 hours retained its original viability (≈85%) whereas pollen with a high (32% to 34%) moisture content exhibited low (≈22%) viability after storage at -18 °C for ≥24 hours. Pollen stored for 140 days at 4 or -18 °C and 13% to 51% RH yielded as many viable seeds per fruit as fresh pollen. Although S. truncata pollen is tricellular, it tolerates desiccation to a low (4%) moisture content and can be stored at temperatures below 0 °C.
Identification and Characterization of S-RNases in Tetraploid Sour Cherry (Prunus cerasus)
Authors: Yamane Hisayo , Tao Ryutaro , Sugiura Akira , Hauck Nathanael R. , Iezzoni Amy F.
Published: January 2019

This report demonstrates the presence of S-ribonucleases (S-RNases), which are associated with gametophytic self-incompatibility (SI) in Prunus L., in styles of self-incompatible and self-compatible (SC) selections of tetraploid sour cherry (Prunus cerasus L.). Based on self-pollen tube growth in the styles of 13 sour cherry selections, seven selections were SC, while six selections were SI. In the SI selections, the swelling of pollen tube tips, which is typical of SI pollen tube growth in gametophytic SI, was observed. Stylar extracts of these selections were evaluated by two-dimensional polyacrylamide gel electrophoresis. Glycoproteins which had molecular weights and isoelectric points similar to those of S-RNases in other Prunus sp. were detected in all selections tested. These proteins had immunological characteristics and N-terminal amino acid sequences consistent with the S-RNases in other Prunus sp. Two cDNAs encoding glycoproteins from `Erdi Botermo' were cloned. One of them had the same nucleotide sequence as that of S4-RNase of sweet cherry (Prunus avium L.), while the amino acid sequence from the other cDNA encoded a novel S-RNase (named Sa-RNase in this study). This novel RNase contained two active sites of T2/S type RNases and five regions conserved among other Prunus S-RNases. Genomic DNA blot analysis using cDNAs encoding S-RNases of sweet cherry as probes indicated that three or four S-RNase alleles are present in the genome of each selection regardless of SI. All of the selections tested seemed to have at least one S-allele that is also found in sweet cherry. Genetic control of SI/SC in tetraploid sour cherry is discussed based on the results obtained from restriction fragment length polymorphism analysis.