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Four-year-old American ginseng (Panax quinquefolium L.) plants and soil samples were collected from nine ginseng gardens. Soil and leaf mineral contents were determined and six major ginsenosides, Rb1, Rb2, Rc, Rd, Re, and Rg1, were extracted from leaves and roots and quantified by high-performance liquid chromatography (HPLC). Correlation coefficients were more significant for soil nutrient levels vs. ginsenoside contents of leaves than of roots, suggesting that soil nutrient levels may play a major role in the synthesis of leaf ginsenosides. Minor elements in the leaf were also better correlated with ginsenoside contents of the root than that of the leaf. Iron content in the leaves exhibited highly significant correlations with the levels of Rb1, Rb2, Rc, and Rd, but calcium and copper contents were negatively correlated with Rg1 in the roots.

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The annual bedding plants `Dazzler Rose Star' impatiens (Impatiens wallerana), `Cooler Blush' vinca (Catharanthus roseus), `Orbit Cardinal' geranium (Pelargonium × hotorum), `Janie Bright Yellow' marigold (Tagetes patula) and `Bingo Azure' pansy (Viola tricolor) were grown on germination papers treated with deionized water (DI), 2500 or 5000 mg·L-1 (ppm) humic acid (HA) or nutrient control (NC) solutions. Seedlings grown on HA-treated germination papers had higher dry root weights than those grown on DI or NC-treated germination papers. Except for impatiens, seedlings germinated on HA-treated germination papers had higher lateral root numbers and higher total lateral root lengths than those grown on DI and NC-treated germination papers. Impatiens grown on NC-treated germination papers had higher lateral root numbers than those grown on DI or HA-treated germination papers. Overall, lateral root numbers for impatiens were higher for seedlings germinated on HA-treated papers than DI or NC-treated papers and highest lateral root numbers occurred on those impatiens germinated on papers treated with 5000 mg·L-1 HA. Except for geranium, seedlings grown in HA-amended sphagnum-peat-based substrates had similar dry root and dry shoot weights as those grown in unamended substrates. Geranium seedlings grown in HA-amended sphagnum peat-based substrates had significantly higher dry root weights than those grown in unamended substrates. However, dry shoot weights of geranium grown in HA-amended sphagnum peat-based substrates were similar to those grown in unamended substrates.

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Abstract

Shoot tips from ‘Marechal Foch’ and ‘Cascade’ were pretreated in 6-benzylamino purine (BA) solution at 0, 1.33 × 10−3, 2.22 × 10−3, or 3.94 × 10−3 m and cultured in media containing naphthaleneacetic acid (NAA) at 0, 2.9 × 10−6 or 5.7 × 10−6 m. Higher concentrations of either BA or NAA reduced the effectiveness of the other in increasing dry weight of shoot tips. Shoots obtained were pretreated in indolebutyric acid (IBA) at 0, 1.48 × 10−3, 2.46 × 10−3, or 3.94 × 10−3 m and then placed in water, half-strength, or full-strength Murashige and Skoog medium (MS). Rooting of both cultivars was improved by IBA pretreatment with maximum rooting at concentrations of 2.46 × 10−3 or 3.94 × 10−3 IBA and usually in half-strength MS.

Open Access

Abstract

Plants of 3 strawberry cultivars, an everbearer (‘Geneva’), and 2 June bearers (‘Catskill’ and ‘Frontenac’) were grown in growth chambers to determine the effects of photoperiod, light intensity, and night temperature upon flowering and runner development. In one experiment, plants dug in the fall and stored at −2° C until spring were compared with spring-dug plants.

The most important factor affecting response was photoperiod. Eighteen hour photo-periods (LD) or continuous light promoted flowering in ‘Geneva’ and runner production in ‘Catskill’ relative to 12 hour photoperiods, while response of ‘Frontenac’ varied in 2 experiments. A light break during a long night simulated LD conditions in ‘Catskill’, but not in ‘Geneva’, and was more consistent than LD in promoting runner development in ‘Frontenac’.

The effects of light intensity were mainly quantitative, 2400 f-c increasing inflorescence or runner production (depending upon cultivar) in comparison with 1200 f-c.

Night temperature did not affect inflorescence or runner production independently of other factors, except for greater runner production with low night temperature (15° C) in ‘Frontenac’.

Time of digging was tested only in ‘Geneva’ and ‘Frontenac’. Fall digging increased the number of inflorescences formed and reduced runner production in ‘Geneva’.

Open Access

Abstract

In the article “Dry Matter Distribution and Responses to Pruning Within a Population of Standard, Semidwarf, Compact, and Dwarf Peach Seedlings”, by Ralph Scorza, Li Zailong, G.W. Lightner, and Lenard E. Gilreath (J. Amer. Soc. Hort. Sci. 111:541–545, July 1986), Table 2, under the “Variable” column, which reads “Avg length of shoots (cm)”, should read “Avg length of shoots (mm)”.

Open Access

Abstract

The ionic Ca content of expressed apple juice conceivably could be used to estimate the total calcium content of fruit flesh. To evaluate this method, samples of 2 strains of ‘Delicious’ apple (Malus domestica Borkh.) were analyzed at 2- to 3-week intervals, from 4 weeks after full-bloom until full-maturity. Ionic Ca in the juice (juice Ca) was analyzed with a selective electrode, total Ca in the flesh (flesh Ca) with a plasma emission spectrophotometer. The correlation coefficient between calcium concentration in flesh vs. juice was very low during the early stages of fruit development, but increased to +0.758 (significant at P<0.0l) for samples collected 5, 3, and 0 weeks prior to fruit maturity. The correlation was generally significant at P<0.01 when all sampling dates were used (r = 0.734 for ‘Miller Spur’, +0.928 for ‘Starking’, and +0.831 for both strains). The calcium concentration in juice samples taken within 35 days of physiological fruit maturity paralleled the calcium concentration in the flesh on any given date, but was not a reliable predictor of flesh Ca concentration in fruit harvested 2 to 3 weeks thereafter.

Open Access

Inheritance of three major genes involved in synthesis of aliphatic glucosinolates (GSL) was followed in segregating populations of Brassica oleracea L. generated from three crosses: broccoli × cauliflower, collard × broccoli, and collard × cauliflower. Two of these genes, GSL-PRO and GSL-ELONG, regulate sidechain length. The action of the former results in three-carbon GSL, whereas action of the latter produces four-carbon GSL. We determined that these two genes act and segregate independently from each other in B. oleracea. The double recessive genotype produces only trace amounts of aliphatic GSL. The third gene, GSL-ALK controls sidechain desaturation and, as it has been observed in Arabidopsis thaliana (L.) Heynh., we found that this gene cosegregates with a fourth gene, GSL-OH, that is responsible for sidechain hydroxylation. Elucidation of the inheritance of major genes controlling biosynthesis of GSL will allow for manipulation of these genes and facilitate development of lines with specific GSL profiles. This capability will be important for improvement of Brassica breeding lines with high content of desirable GSL, like glucoraphanin, a demonstrated precursor of anticarcinogenic compounds. Additionally, this work is the first step towards cloning the major genes of the aliphatic GSL pathway, and to use these clones in transformation strategies for further crop enhancement.

Free access

Abstract

Three-year-old limbs of unpruned standard (ST), semidwarf (SD), compact (CT), and dwarf (DW) seedling peach [Prunus persica (L.) Batsch] trees were separated into component parts at harvest. CT and DW trees had allocated higher percentages of dry matter to one- and 2-year-old branches than ST and SD trees. Although the proportion of dry weight in current season shoots was highest in CT trees compared with the other tree types, fruit dry weight was relatively low. In a separate study ST, SD, and CT trees were pruned and left unpruned, and current season shoot and fruit growth was recorded. Pruning increased the wood dry weight per trunk cross sectional area in current season growth in ST trees and increased the average length of shoots and lowered light penetration in ST and SD trees, but pruning did not affect current season shoot dry weight or length in CT trees. Shoot dry weight and shoot length were greatest in pruned ST trees. The number of shoots was not affected by pruning in any tree type. Total fruit dry weight did not differ with pruning or tree type.

Open Access

The procedure for Heuchera villosa ‘Caramel’ propagation was investigated, which involves shoot regeneration, rooting of regenerated shoots, and acclimation of regenerated plantlets. Petioles, as explants, were cultured on MS medium supplemented with 1-naphthylacetic acid (NAA), benzylaminopurine (BA), thidiazuron (TDZ) and callus formed on all media. Shoots were observed to proliferate from callus on media with BA and NAA, whereas no shoots regenerated on media with TDZ and NAA. On media containing 0.5 or 1.0 mg·L−1 BA in combination with NAA, the regenerated shoots showed severe hyperhydricity, whereas on media containing 0.1 mg·L−1 BA in combination with NAA, the regenerated shoots grew normally. The highest shoot induction rate, 90.6%, was obtained on media containing 0.1 mg·L−1 BA and 0.01 mg·L−1 NAA. The effects of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and NAA on rooting of H. villosa ‘Caramel’ was explored. The highest rooting rate (95%) was obtained on 1/2 MS medium containing 0.2 mg·L−1 NAA. In the subsequent acclimation experiments, about 85% of rooted plantlets survived and grew normally.

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Randomly amplified polymorphic DNA (RAPD) markers were utilized to determine the genetic relationships of nine morphologically similar pot plant cultivars of Anthurium sp. by developing DNA fingerprints (DFP). Of 25 arbitrary primers screened, nine generated DFPs that were used in computing the genetic distance (d) and similarity coefficient (C) values. All cultivars tested exhibited a high degree of genetic similarity. `Lady Ann' and `Lady Beth' possessed the closest relationship with d and C values of 0.06 and 0.98, respectively. The next closest genetic relationship was between `Red Hot' and `Southern Blush' (d = 0.33, C = 0.89). These two cultivars exhibited a more distant relationship to the other seven cultivars as indicated by higher `d' values. However, this study showed that the nine Anthurium cultivars examined were genetically closely related. These cultivars share specific DNA bands with three possible parental species (A. andraeanum Linden ex Andre, A. antioquens L., and A. amnicola Dressler) included in this study, which may indicate similarities in their pedigree. This study shows that RAPDs can be a useful tool to distinguish Anthurium pot plant cultivars as well as identify their genetic relationships.

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