bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micropropagation and Phase Specificity in Mature, Elite Douglas fir
Authors: Gupta Pramod K. , Durzan Don J. 
Published: August 2022

Abstract
Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] plantlets, micropropagated from axillary buds of nodal segments from invigorated stems and adventitious buds from young needles of two 60-year-old trees, have been established in soil. Stem tips with half-pruned-back needles from the lower crown, when placed on DCR medium, sprouted buds in 90% of explants. Shoots from bud sprouts were plagiotropic when collected from explants of shoots with a horizontal and downward growth habit. By contrast, upright growth of micropropagated shoots was observed in all explants from branches with an upright habit. After four subcultures (3- to 4-week intervals on 0.5 mg·liter−1 BA in DCR), sprouted shoots of nodal segments from all expiant sources produced four to six multiple buds. With excised needles of sprouted buds, numerous (> 10) adventitious buds formed after 11 to 12 weeks on needle surfaces after the fifth subculture on DCR with 0.5 mg·liter BA. All adventitious and axillary buds elongated on 0.5 DCR lacking plant growth regulators. Rooting of the elongated shoots was induced in 20% of the explants with 0.2 mg·liter−1 each of NAA and IBA. In all instances, buds programmed for the development of female reproductive cones continued their phase-specific development even under conditions conducive to rejuvenation of vegetative tissues. Chemical names used: N-(phenylmethy)-1H-purin-6-amine (BA); 1-naphthaleneacetic acid (NAA); 1H-indole-3-butyric acid (IBA).
Discriminant Analysis for Kentucky Bluegrass Billbug Resistance Ratings
Authors: Bruneau A.H. , Parkhurst A.M. , Shearman R.C. 
Published: August 2022

Abstract
Four categories of billbug (Sphenophorus parvulus Gyllenhal) resistance were identified and contrasted in terms of anatomical, morphological, and physiological characteristics of 12 Kentucky bluegrass (Poa pratensis L.) cultivars. Discriminant analysis was used as a separatory procedure to determine the relative importance of these plant characteristics to observed billbug resistance and to construct a prediction procedure for potential billbug resistance classes. Variables measured from field-, controlled environment-, and greenhouse-grown plants were analyzed for the most biologically revealing characteristics of potential billbug resistance. Separatory discrimination indicated that cultivars exhibiting moderate and high billbug resistance had tougher tissue than tolerant or susceptible cultivars. Tolerant and highly resistant cultivars differed from those susceptible and moderately resistant by concealing billbug injury. Development of a predictive classification procedure was promising, with percent correct classification ranging from 67% to 94%, depending on number and type of discriminating variables analyzed.
Fertility of 4x × 5x and 5x × 4x Progenies Derived from Vaccinium ashei/corymbosum Pentaploid Hybrids
Authors: Vorsa Nicholi , Jelenkovic Gojko , Draper Arlen D. , Welker William V. 
Published: August 2022

Abstract
Percent fruit set, fruit size, total seeds/berry, developed seeds/berry, percent developed seeds/berry, and percent pollen stainability were examined in 4x × 5x and 5x × 4x progenies derived from Vaccinium ashei Reade/V. corymbosum L. pentaploid hybrids backcrossed to V. corymbosum. All fertility parameters indicated that the BC1 progenies were more fertile than the pentaploid hybrids. Pollen stainability indicated that the BC1 derivatives were less fertile than the parental species. All fertility parameters were significantly and negatively correlated with chromosome number, which ranged from the tetraploid (2n = 4x = 48) to pentaploid (2n = 5x = 60) levels within these progenies.
Identification and Performance of Citrus Trees on Nucellar and Zygotic Rootstocks
Authors: Roose M.L. , Traugh S.N. 
Published: August 2022

Abstract
Electrophoretic analysis of rootstock bark was used to identify citrus trees on zygotic rootstocks in five 9- to 19-year-old rootstock trials involving 24 rootstock cultivars, and in four additional 22- to 23-year-old rootstock trials involving 24 selections of trifoliate orange [Poncirus trifoliata (L.) Raf.]. The rootstock seedlings used to propagate the trees for these trials were rogued visually before budding. The theoretical probability of distinguishing between nucellar genotypes and zygotics resulting from self-pollination averaged ≈86% among the rootstocks studied. In cultivars other than trifoliate orange, only 17 of 899 rootstocks were detected to be zygotic: eight in Kikodaidai, four in H-56 tangor, two in C-32 citrange, and one each in three other rootstocks. Many of these zygotics resulted from cross-pollination. In trifoliate orange, 29 of 846 trees were identified to be on zygotic rootstocks, all apparently resulting from pollination by trifoliate orange. Some trees on zygotic rootstocks were smaller and lower-yielding than trees on nucellar genotypes of the same cultivar, but many were fairly similar to, and a few yielded significantly more than, trees on nucellars. Trees on zygotic rootstocks usually had bud unions that were either significantly more or less smooth than trees on nucellars of the same cultivar. Data from zygotics did not bias results of rootstock trials appreciably. Isozyme analysis of rootstocks in commercial groves or rootstock trials may allow preliminary identification of promising new genotypes resulting from open pollination.
Frequency and Characteristics of Nucellar and Zygotic Seedlings in Three Cultivars of Trifoliate Orange
Authors: Khan I.A. , Roose M.L. 
Published: August 2022

Abstract
Seedling populations of three cultivars of trifoliate orange [Poncirus trifoliata (L.) Raf.] were grown in a greenhouse from seed collected in three different years and four different locations. Starch gel electrophoresis of four heterozygous loci was used to distinguish nucellar (apomictic) seedlings from zygotic seedlings. Minimum estimates of the frequency of zygotics among 23 seed samples ranged from 0% to 76%, with an overall mean of 18%. All zygotics apparently originated from self-pollination or pollination by other trees of trifoliate orange. Samples collected from the same tree in different years had significantly different frequencies of zygotics. Differences among cultivars in frequency of zygotics were obscured by the large environmental effects. Samples stored for 8 months before planting generally did not differ in frequency of zygotics from those stored for 5 months. Mean height of zygotics was less than that of nucellars in all samples measured, significantly less in most samples. However, many zygotics were so similar to nucellars in height, leaf size, thorn length, petiole length, and stem diameter that they would be difficult to identify using these traits.
Role of Assimilate Translocation and Carbohydrate Accumulation in Fruit Set of Strawberry
Authors: Darnell Rebecca L. , Martin George C. 
Published: August 2022

Abstract
Soluble sugar and starch levels and translocation of 14C-Iabeled photoassimilates in receptacles of pollinated, nonpollinated, and auxin-treated strawberry flowers (Fragaria × ananassa Duch. ‘Fern’) were examined from 0 to 144 hr after anthesis and correlated with fruit set and initial growth. Receptacle dry weight of nonpollinated flowers increased very little during the experimental period, whereas receptacles of pollinated and auxin-treated flowers showed a gain in dry weight within 24 hr, which continued throughout the experimental period. However, 14C accumulation in flower receptacles did not reflect the initial differences in growth, indicating that recently fixed 14C-labeled photosynthate was not the source for the observed dry weight increases. Analysis of carbohydrate pool sizes in treated receptacles indicated no consistent correlation between pool sizes and fruit set and initial growth. Thus, fruit set and initial growth in strawberry is not limited by the capacity of receptacles either to mobilize current source leaf assimilates or accumulate carbohydrates.
Whole-fruit Ethylene Evolution and ACC Content of Peach Pericarp and Seeds During Development
Authors: Miller Anita Nina , Krizek Beth Allyn , Walsh Christopher S. 
Published: August 2022

Abstract
The rate of ethylene evolution of peach fruit (Prunus persica L. Batsch) and ACC content of peach pericarp/mesocarp and seeds was determined during development. Ethylene measurements of whole fruit began 18 days after anthesis (DAA), and ACC quantification was started 32 DAA. ACC levels and ethylene evolution followed similar patterns during stages I and II of fruit growth. At 39 DAA, there was an increase in ethylene evolution and extractable ACC concentration of both pericarp and seeds; however, variability was high at this time. Ethylene evolved by nondeveloping fruit of the “second wave” and “June drop” increased after senescence of the ovule was observed. By 49 DAA, ethylene production and ACC concentration reached a minimum that lasted until a 10-fold increase in ethylene evolution was detected in late stage III. This 10-fold increase in ethylene occurred in four different peach cultivars sampled at “firm-ripe” stage. Seeds excised at 67 DAA, which were incubated for 6 hr in ambient O2 conditions, evolved 400 nl·g−1·hr−1 ethylene and ACC concentration averaged 54 nmol·g−1 fresh weight. It is suggested that in split-pit fruits, ethylene generated by the seeds may accelerate fruit maturation and ripening. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).
Development of the Abscission Zone in Needles of Douglas-fir
Authors: Montano Jose M. , Proebsting William M. 
Published: August 2022

Abstract
The abscission zone of Douglas-fir (Pseudotsuga menziesii var. menziesii Mitb. Franco) was studied throughout needle development. A separation layer one cell thick developed at the needle base when extension growth ceased. Cells of this layer stained positively with safranin and slightly with toluidine blue. A protective layer, which developed in stem tissue adjacent to the separation layer, stained positively with safranin, periodic acid-Schiff's reagent, phloroglucinol-HCL and chlorine sulfite. Abscission was induced by drying cut trees to a water potential below −3.5 MPa. Water-stressed trees segregated into abscising and non-abscising needle groups. Walls of separation layer cells from trees with abscising needles were characterized by shrinkage followed by tearing. Walls of separation layer cells from trees with non-abscising needles were anatomically unaffected by water stress. Mechanical damage of cell walls in the separation layer occurred when water stress was −3.5 MPa or lower. Abscission could be prevented by maintaining a water potential above −3.5 MPa.
Micropropagation of Cherry Rootstocks: I. Response to Culture
Authors: Ranjit Makunda , Kester D.E. , Micke W.C. 
Published: August 2022

Abstract
Establishment, shoot proliferation, root induction, and transplanting stages were accomplished with Prunus avium × P. cerasus cv ‘Colt’, ‘Dwarf Mahaleb’ (P. mahaleb L) (both vegetatively propagated rootstock cultivars) and seedling Mazzard sweet cherry (P. avium L) ‘46-1 Mazzard’, (P. avium L.), a clonal rootstock seed tree, could be established and multiplied by the same procedure. However, no rooting was obtained. Limited rooting was possible with seedling Mazzard trees < 3 years in age. It was concluded that the limiting factor in ‘46-1 Mazzard’ rooting was the mature status of the source material.
Effects of Phenolic Compounds on Tobacco Callus and Blackberry Shoot Cultures
Authors: Compton Michael E. , Preece John E. 
Published: August 2022

Abstract
The effects of catechol, juglone, phloridzin, phloroglucinol, and tannic acid were tested on tobacco callus growth and on axillary shoot proliferation and rooting of blackberry. Juglone (500 μM) promoted tobacco (Nicotiana tabacum L. ‘McNair 944’) callus growth, whereas catechol and phloroglucinol (500 μM) increased adventitious shoot formation, but not callus growth. Tannic acid increased the frequency of vitreous shoots. No phenolic compounds stimulated axillary shoot proliferation in blackberry (Rubus sp. ‘Dirkson Thornless’), and phloroglucinol (1 mM) inhibited shoot elongation. Auxin increased rooting of blackberry shoots irrespective of the presence or absence of incorporated phenols. On shoots derived from proliferation media void of phenols, root number and percent rooting were greater if they were treated with the phenolic auxin P-ITB compared to IBA. In contrast, shoots originating from proliferation media containing phenols rooted the same with both auxins. Chemical names used: 1,2-benzenediol (catechol); 5-hydroxy-1,4-naphthalendedione (juglone); 1-[2-(β-D-glycopyranosloxy)-4,6-dihydroxyphenyl-3-[4-hydroxyphenyl)-1-propanone (phloridzin); 1,3,5-benzenetriol (phloroglucinol); 1H-indole-3-butanoic acid (IBA); N-(phenylmethyl)-1H-purin-6-amine (BA): phenyl indole-3-thiolobutyrate (P-ITB); (1α,2β,4aα,4bβ,10β)-2,4a,7-trihydroxy-1-methyl-8-methylenegibb-3-ene-1, 10-dicarboxylic acid 1,4a-Iactone (GA3).
Sensitivity of Peach Seedling Vegetative Growth to Paclobutrazol
Authors: Early J.D. , Martin G.C. 
Published: August 2022

Abstract
‘Nemaguard’ peach seedlings [Prunus persica (L.) Batsch] were grown for 21 days in nutrient solution cultures containing a range (0 to 3.4 μM) of paclobutrazol concentrations. Shoot growth rate and total extension growth were reduced by all paclobutrazol treatments. Within 2 days of treatment, paclobutrazol at 3.4 μM significantly reduced the growth rate, as did the 3.4 × 10−2 μM concentrations after 5 days. Increases in paclobutrazol concentrations decreased leaf area and leaf, stem, and shoot weights. However, specific leaf weight increased as paclobutrazol concentration increased. Leaf expansion was more sensitive to paclobutrazol treatments than stem elongation. As paclobutrazol concentration increased, root extension growth was reduced, but roots were thicker and produced more laterals near the tip. Compared with the control, paclobutrazol at 3.4 × 10−1 and 3.4 × 10−2 μM significantly increased the root: shoot ratio. Chemical name used: β-[(4-chIorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Gradients in Maturity and Sugar Levels of Fruit Within Peach Trees
Authors: Dann Ian R. , Jerie Peter H. 
Published: August 2022

Abstract
Peach [Prunus perscia (L.) Batsch] flowers opened first at the base of young trees and last at the top. In contrast, fruit ripened first at the top of trees and at the tips of laterals. Dry weight and percentage dry weight (% dwt) of the mesocarp of fruit from the upper canopy were consistently greater throughout the season than for fruit from the lower canopy. These differences were large enough to have marketing significance and important implications for the future of mechanical harvesting.
Influence of Temperature and Plant Water Status on Pollen Viability in Beans
Authors: Weaver Merle L. , Timm H. 
Published: August 2022

Abstract
The effect of temperature, soil moisture, and diurnal variations in plant water content on pollen viability (PV) in bean (Phaseolus vulgaris L.) genotypes was investigated under field conditions in 1981 and 1982. Each year PV, relative water content (RWC), and leaf water potential (LWP) of each cultivar at mean soil moisture tensions (MSMT) of −0.05 and −0.10 MPa were reduced significantly between 0700 hr and 1400 hr. At a MSMT of −0.05 MPa, PV and RWC of both cultivars significantly increased between 1400 hr and 1900 hr. During the same period, the LWP of ‘California Light Red Kidney’ increased to the 0700-hr level, but remained at the 1400-hr level in ‘Gloria’. At a MSMT of −0.10 MPa, PV significantly increased in ‘Gloria’ but failed to increase in ‘California Light Red Kidney’ between 1400 hr and 1900 hr. RWC remained at the 1400-hr level in both cultivars. LWP of ‘California Light Red Kidney’ remained at the 1400-hr level, but continued to decline below the 1400-hr level in ‘Gloria’ during the same period. PV declined as both RWC and LWP decreased. A relative value for the simultaneous contribution of both high ambient temperature and the water status of bean plants to loss of PV was calculated.
Mulch and Irrigation Placement Effects on Soil Chemistry Properties and Rabbiteye Blueberry Plants Irrigated with Sodic Water
Authors: Patten K.D. , Neuendorff E.W. , Leonard A.T. , Haby V.A. 
Published: August 2022

Abstract
‘Tifblue’ rabbiteye blueberry (Vaccinium ashei Reade) plants were grown for 3 years under a sodic irrigation regimen. Mulched and non-mulched plants were irrigated by one of three methods: one drip emitter at the base of the plant, two drip emitters on either side of the plant, or low-volume spray emitter (LVSE). There was a mulch × irrigation treatment interaction. Mulch increased the growth of drip-irrigated plants but not LVSE-irrigated plants. Salt-induced leaf chlorosis and necrosis was only evident on plants with no mulch and irrigated with two emitters. Under mulched soil, K, Na, Mg, Cl, electrical conductivity (ECe), and Na adsorption ratio (SAR) levels were several times lower and uniform throughout the soil profile compared to the non-mulched treatments. Maximum root-zone salinity was 3.7 dS·m−1 for two emitters without mulch and a minimum of 0.5 dS·m−1 for one emitter with mulch.
Quantifying Temperature-controlled Leaf Unfolding Rates in ‘Nellie White’ Easter Lily
Authors: Karlsson M.G. , Heins R.D. , Erwin J.E. 
Published: August 2022

Abstract
The rate of leaf unfolding was determined for Easter lily (Lilium longiflorum Thunb.) ‘Nellie White’ grown at day and night temperatures ranging from 14° to 30°C. In this temperature range, rate of leaf unfolding was a linear function of average daily temperature; i.e., the effect on rate of leaf unfolding for day temperature was the same as for night temperature. The function determined was: leaves unfolded per day = −0.1052 + (0.0940 × average daily temperature). Isopleth plots were developed to describe day and night temperatures required for specific rates of leaf unfolding under 8-, 10-, and 12-hr day temperature periods.
Influence of Photoperiod and Growth Regulators on Flowering of Rhipsalidopsis gaertneri
Authors: Boyle Thomas H. , Jacques Daniel J. , Stimart Dennis P. 
Published: August 2022

Abstract
Plants of Rhipsalidopsis gaertneri [Regel] Moran ‘Crimson Giant’ were given continuous 14-hr long-days (LD), provided by 8-hr daylight plus 6-hr incandescent (Inc) irradiation; continuous 8-hr short-days (SD), provided by daylight; 2, 4, 6, or 8 weeks SD, then LD; or 2, 4, 6, 8 weeks LD, then SD. All plants receiving continuous LD or 2, 4, 6, or 8 weeks SD then LD flowered, whereas some or all plants in other photoperiod regimes failed to flower. Earliest and most prolific flowering occurred in response to 4, 6, or 8 weeks SD then LD. In a second experiment, plants previously given 8 weeks of 8-hr daylight (SD) were transferred to one of the following photoperiods: 12-, 14-, 16-, or 20-hr (8 hr daylight plus = to 12-hr Inc irradiation); 8-hr daylight plus 4-hr Inc night interruption (NI); or 8-hr daylight (SD). All plants receiving photoperiods of 12 to 20 hr or 4-hr NI flowered. Days from start of photoperiod treatments to visible flower buds was inversely related to duration of the Inc irradiation period, with a 4-hr NI comparable to 16-hr day. Days required for visible flower buds to complete development (flower expansion) were largely unaffected by duration or timing of Inc irradiation. Application of BA delayed flowering but more than doubled the number of flower buds per flowering apical phylloclade. Flower bud abortion was increased and both flower fresh weight and flower diameter were diminished by BA. Application of STS did not reduce flower bud abortion on BA-treated plants, but increased the percentage of apical phylloclades flowering. Chemical name used: N-(phenylmethyl)-lH-purin-6-amine (BA), silver thiosulfate (STS).
Studies on Octylphenoxy Surfactants: V. Toxicity to Cowpea Leaves and Effects of Spray Application Parameters
Authors: Lownds N.K. , Bukovac M.J. 
Published: August 2022

Abstract
Surfactant toxicity was examined following application of octylphenol and linear alcohol surfactants to the adaxial surface of 10-day-old cowpea [Vigna unguiculata (L.) Walp. subsp. unguiculata ‘Dixielee’] leaves. Leaf damage first appeared as isolated discolored areas at the periphery of the droplet area, developed toward the center, and, when most severe, the entire droplet area was necrotic. Epidermal cells beneath the droplet area became discolored, lost structural integrity and collapsed. Similar changes were observed in the palisade layer and spongy parenchyma. In addition, walls of damaged cells were preferentially stained with Safranin O. For a given surfactant dose, phytotoxicity increased with increasing concentration, droplet volume, and temperature and decreased with increasing humidity. In general, phytotoxicity was inversely related to the length of the ethoxy (EO) chain for both the octylphenol (Triton X) and C12-15 linear alcohol (Neodol 25) surfactant series. Tissue did not recover after injury. Chemical names used: octylphenoxypoly(ethoxy)ethanol (Triton X-100), linear alcohol ethoxylate (Neodol 25-9).
Longevity of Pistachio Pollen Determined by in Vitro Germination
Authors: Polito Vito S. , Luza Juvenal G. 
Published: August 2022

Abstract
Pistachio (Pistacia vera L.) pollen was examined for capacity to germinate in vitro 2 days after anthesis and at intervals of time after storage at ambient laboratory conditions or at − 20°C. In 1986, fresh pollen of each of four clones examined had high germination percentages on a range of sucrose and agar concentrations. After 1 week at room temperature, germination percentages were < 6%. However, when the same week-old pollen was treated to effect gradual hydration at high humidity prior to being placed on the germination medium, germination increased to > 80% for ‘Peters’ pollen and 10.4% to 63.8% for the three other clones. In 1987, similar results were obtained for ‘Peters’ pollen, where pollen hydrated at high humidity had germination rates at least 50% that of fresh pollen when stored up to 18 days at ambient laboratory temperature and humidity. Pollen stored at −20° showed more exacting in vitro germination requirements than fresh pollen, particularly as time in storage increased. ‘Peters’ pollen retained germination levels comparable to fresh pollen after 4 months at −20°, but, by 12 months, germination percentages had fallen sharply.
Rooting Cofactors in Five Acer Species
Authors: Kling Gary J. , Meyer Martin M. , Seigler David 
Published: August 2022

Abstract
Methanolic extracts from leaves, young stems, and old stems of five Acer (maple) spp. were tested for their effects on adventitious root initiation in mung bean (Vigna radiata Wilcox’) cuttings. An extract from the leaves of A. ginnala strongly stimulated root initiation, and the active compounds in this fraction were not synergistic with IAA. This extract was more stimulatory than IAA on mung bean cuttings and stimulated root initiation in softwood cuttings of A. saccharinum and A. griseum. Preliminary characterization of this extract indicates that it is a phenolic compound and/or a weak acid. Chemical name used: 1H-indoIe-3-acetic acid (IAA).