bluuebunny/crossref_metadata_2025 huggingface dataset:
(243) Release of New Scaevola sericea Cultivars
Authors: McConnell James
Published: February 2019

Scaevola sericea is a plant native to Guam. The normal flower has petals that are usually white with slight, thin, magenta bands. The seeds for these plants were collected from a parent plant with dark magenta flowers growing in the wild. Plans are to self the parent plant to observe the variation in the seedling population. Four selections of S. serica were made and are being propagated for public release. Three of these selections have white petals with broad magenta bands or spots on the flower petals, in contrast to the usual white flower. One selection has a floral fragrance.
(187) The Use of Essential Oils as Natural Preservatives for Berry Fruits
Authors: Wang Chien
Published: February 2019

Berry fruits such as blackberries (Rubus sp.) and blueberries (Vaccinium corymbosum L.) are highly perishable after harvest. In addition to rapid deterioration in quality, they are also very susceptible to microbial invasion. The shelf life of these berries is usually terminated by decay. Several natural antimicrobial compounds derived from essential oils of plants were studied for their efficacies in inhibiting decay and extending shelf life of berry fruits. The severity of decay in blackberries and blueberries stored at 10 °C was significantly reduced by treatment with thymol. Treatments with menthol or eugenol also suppressed the fungal growth, but to a lesser extent. All of these three natural antimicrobial compounds extended shelf life of blackberries and blueberries as compared to the control. Berries treated with thymol, menthol, or eugenol also maintained better fruit quality with higher levels of sugars, organic acids, and oxygen radical absorbance capacity than the untreated fruits. The effects of these natural antimicrobial agents on the quality and shelf life of other fruits will be investigated.
(188) Effects of Storage Temperatures on the Antioxidant Capacity and Anthocyanin Contents of Black Raspberries
Authors: Tulio Artemio Z. , Chanon Ann M. , Janakiraman Nithya , Ozgen Mustafa , Stoner Gary D. , Reese R. Neil , Miller A. Raymond , Scheerens Joseph C.
Published: February 2019

This study was conducted to determine the effects of postharvest storage temperatures on the antioxidant capacity, anthocyanin compounds, phenolic constituents, and physico-chemical properties of black raspberries. Fresh `MacBlack' berries were stored at 4, 12, 20, and 28 °C for up to 11, 6, 4, and 3 days, respectively. Results showed that higher storage temperatures promoted tissue deterioration (cellular leakage), fungal growth, and moisture loss. The levels of the two major anthocyanins, cyanidin 3-rutinoside and cyanidin 3-xylosylrutinoside, increased by up to 2.7- and 1.9-fold, respectively, with increasing storage temperatures. The antioxidant capacity of berries, as measured by FRAP and ABTS assays, increased by up to 1.5- and 1.4-fold, respectively, which was accompanied by increases in soluble solids, total sugars, total phenolics, and total anthocyanin contents. Our findings indicate that postharvest storage at higher temperatures increases the level of bioactive compounds and antioxidant capacity in black raspberries, but this increase may be due in part to moisture loss and sugar metabolism. Storage at 4 °C maintained the level of bioactive compounds and antioxidant capacity present at harvest and prolonged the effective shelf life of the product. Further studies of black raspberry bioactive components as influenced by postharvest conditions and processing procedures (e.g., IQF, freeze-drying, air-drying) are warranted.
(190) Sensory Quality and Postharvest Performance of Southern Highbush Blueberry Cultivars Grown in Southern California
Authors: Mitcham Elizabeth , Biasi William , Gaskell Mark , Faber Ben , Lobo Ramiro
Published: February 2019

Blueberry fruit were harvested at commercial maturity from variety trials and shipped overnight to UC Davis. Fruit quality was evaluated upon receipt and after 6 and 20 days of cold storage at 0.5 °C in air shelf life. Firmness, external color, soluble solids, and titratable acidity were measured. Sensory evaluations were conducted by trained tasters to rate the blueberries for crispness, mealiness, sweetness, tartness, blueberry flavor, and off-flavors at harvest and again after 21 days of storage. Many of the blueberries increased in firmness during cold storage. Firmness at harvest tended to be softer in `Santa Fe' and `Jewel' and firmer in `Star'. Sensory data also found `Sharpblue' and `Southmoon' to be more firm; however the objective measurements did not agree. Overall, `Saphire' was low in sugars and acids, and `Jewell' and `Star' were high in acids. `Misty' and `Sharpblue' were consistently high in sugars and acids. Overall objective fruit quality ratings were highest for `Misty', `Sharpblue', and `Southmoon', and lowest for `Santa Fe'. Blueberry flavor was rated highest in `Jewell', `Star', and `Sharpblue', and lowest in `Santa Fe', `Saphire', `Misty', and `Emerald'. These data indicate that blueberry flavor may be closely tied to acid content, as most of the high-flavor varieties had high acid and many of the low-flavor varieties had low acid. Over 3 years, the varieties consistently rated highest for overall objective quality were `Misty' and `Southmoon'. `Star' was rated high for overall quality in 2 years and moderate in 1. `Jewell', `Star', and `Sharpblue' were rated highest in flavor. `Santa Fe' was ranked low in flavor quality in 2 out of 3 years. Selection of variety appears to have a strong influence on the sensory quality of the blueberries marketed.
(246) Is High Carotenoid Content Enough? Oxygen Radical Absorbance Capacity (ORAC) As a Breeding Tool: A High Throughput Strategy and Methodology Validation
Authors: Waters Jennifer L. , King Stephen R.
Published: February 2019

Carotenoids are important phytochemical components of our diet and have gained recent attention as important nutritive compounds found mainly in fruits and vegetables with red, orange, and yellow hues. Lycopene is often cited as being inversely correlated with the occurrence of various cancers, in lowering rates of cardiovascular disease, and improving other various other immune responses. Antioxidant activity, specifically oxidative radical quenching power, is the putative rationale for carotenoids' involvement in disease risk reduction. It is unlikely, however, that carotenoid content and antioxidant capacity are directly correlated in the whole food since there are other antioxidants present in watermelon, such as various free amino acids. A total measure of antioxidant potential may prove to be a useful tool for measuring watermelon nutritional value and implementing pursuant breeding goals. One assay that has gained recent popularity is the oxygen radical absorbance capacity (ORAC) assay. ORAC includes two assays that separate lipophylic and hydrophilic antioxidants. Currently, most ORAC protocols use isolated compounds or freeze-dried fruit or vegetable samples. Here, the application of a standard hexane-type extraction method, which is more amenable to whole food carotenoid-containing samples, was investigated as a candidate extraction method for the ORAC assay. Variants of this method as well as of the standard ORAC extraction were compared for extraction efficiency. Finally, ORAC values were correlated with carotenoid content and shown to hold a loose negative correlation. Possible reasons for this are considered and discussed.
(250) Monogalactosyl-diglyceride Contents in Sweetpotato Clones
Authors: Harrison Howard F. , Peterson Joseph K. , Snook Maurice E.
Published: February 2019

Bioasssay-guided investigation of constituents possibly contributing to the allelopathic potential of sweetpotato led to the isolation of a nonpolar seed germination inhibitor in sweetpotato (Ipomoea batatas L.) roots. Mass spectral data supported by HPLC s pectroscopic analyses and data obtained from hydrolysis products revealed the presence of three monogalactosyl-diglycerides (MGDGs) (galactosyl-di-linoleneoyl glyceride, galactosyl-linoleneoyl-linoleoyl glyceride, and galactosyl-di-linoleoyl glyceride) in storage roots. The compounds inhibited proso millet germination, and at 100 ppm inhibition was about 90%. MGDG with fully saturated fatty acids (galactosyl-distearoyl glyceride) was not inhibitory in the bioassay. An efficient method for quantitation of individual MGDGs was developed, and the contents of each compound in the storage root tissues of 12 genetically diverse cultivars and breeding lines were determined. On a dry weight basis, total MGDG contents ranged between 107 and 452 μg/g in the periderm, 298 and 807 μg/g in the cortex, and 296 and 755 μg/g in the stele. Also, large differences in the ratios of the three compounds between clones and between tissues within a clone were noted. The differences between clones indicate that manipulating total content and ratios of MGDGs through plant breeding is feasible.
(251) Screening Spring-seeded Onion Cultivars for Iris Yellow Spot Virus
Authors: Multani Parminder Singh , Cramer Christopher S.
Published: February 2019

Identification of resistant cultivars offers the best control for Iris yellow spot virus (IYSV), a new onion disease vectored by Thrips tabaci. In this study, 18 spring-seeded onion cultivars were screened for IYSV. Each alternate plot in the field was planted with infected bulbs from the previous year to serve as a source of virus inoculum and thrips. With increased thrips population and temperature over time, straw-colored, necrotic lesions typical to IYSV infection were observed on plant leaves. Plants were analyzed by enzyme linked immunosorbant assay to confirm the IYSV infection and determine the virus titer. Ten randomly selected plants from each plot were rated for IYSV symptoms on a scale of 1 to 9, with 1 representing no symptomatic tissue and 9 representing more than 50% tissue damage. Starting 1 June, disease ratings were collected each week until 13 July. Nearly all cultivars showed similar disease symptoms when rated on 1 June. By 29 June, NMSU 03-52-1 exhibited some tolerance to IYSV as fewer symptoms were observed. By 13 July, NMSU 03-52-1 exhibited fewer disease symptoms than most of the other cultivars tested, while `Caballero' showed the highest IYSV symptoms. All other cultivars showed low to high susceptibility for IYSV. The increase in disease severity was accompanied by a relative increase in the virus titer of plants over time. However, virus titer poorly correlated with the amount of disease symptoms in different cultivars. The most tolerant cultivar, NMSU 03-52-1, had higher virus titer than many susceptible cultivars but still performed well. Conversely, some cultivars with low virus titer were susceptible and developed more symptoms. This indicates a difference in the capabilities of different cultivars to resist IYSV.
(267) The Effects of Media Types on Rescued Peach Embryos
Authors: Anderson Natalie , Byrne David H. , Raseira Maria B.
Published: February 2019

A major obstacle faced by programs that breed early-ripening peach cultivars [Prunus persica (L.) Batsch] is the low viability of the embryos from the early-ripening parents that are used as females. Embryo culture techniques have been developed to allow embryos to mature in vitro, thus increasing the chances of germination and survivability. Several media types exist for Prunus embryo culture. Two types, Woody Plant Medium (WPM) and Smith, Bailey, and Hough (SBH) were investigated for this report. The WPM type was studied in two forms, one made from scratch and the other in a prepackaged form. The SBH type was studied with the addition of vitamins and without vitamins. Eight peach genotypes with embryo lengths ranging from 9.6 to 12.7 mm were used. Surprisingly enough, it was found that WPM from scratch performed better than WPM from a prepackaged mix. For all eight genotypes studied, WPM from scratch resulted in as good as or better germination than SBH with or without vitamins. A large media by genotype effect was found, which is partially attributed to the embryo size. The genotypes with larger embryos (>11 mm) tended to perform equally on all media tested whereas the embryos <10.5 mm germinated better on WPM as compared to SBH.
(194) Quality Parameters in `Flame Seedless' Table Grapes Growing in Two Different Microclimatic Areas in Chile
Authors: Lizana L. Antonio , Sandoval Jorge M. , Pinto Manuel , Luchsinger Luis
Published: February 2019

An experiment was set up to elucidate the causes of differences in harvest time in the adjacent grape-growing areas of Rapel and Sotaqui in the Limari Valley, Chile. Berry samples of `Flame Seedless' were collected from each area, from 10 days after last GA spray until harvest (December to February). Soluble solids (SS), titrable acidity (TA), and SS/TA ratios were analyzed and days from full bloom to harvest, growing degree days, and ambient temperatures were recorded. In Rapel, full bloom was 25 Sept.; the harvest by 16 °Brix, started on 3 Jan., and the harvest by 20:1 SS/TA ratio (min. 15.5 °Brix) on 28 Dec. (11, 16, and 24 days earlier, respectively, than Sotaqui). Degree-days (DD) at harvest (16 °Brix) were 1058 in Rapel and 837 DD in Sotaqui. In the last 50 days prior to harvest, berry acidity was always lower in Rapel, decreasing from 0.87% to 0.47%, while in Sotaqui berry acidity decreased from 1.96% to 0.86%. From 20 Dec. to 2 Jan., the acidity did not decrease significantly (1.96% to 1.84%), but in the next 3 weeks decreased to 0.68%. This difference in the rate of acid degradation is related to the increase in minimum night temperatures in this same period of berry growth. It is concluded that the minimum temperature-dependent rate of organic acid degradation is the main factor influencing the SS/TA harvest index parameter.
(196) A Comparison of Fruit Quality and Antioxidant Properties of Alabama-grown Kiwi
Authors: Kao Ming-Wei S. , Woods Floyd , Dozier William A. , Ebel Robert C. , Lee Chang Y. , Jee Jun Bae
Published: February 2019

The health status of Alabama's population ranks above the national average with respect to the prevalence of poor overall health indicators. Consumer knowledge of the health benefits of consumption of fresh fruit is lacking. The compositional and nutritional qualities of fruit are highly variable among states with different climate, soil, and other environmental conditions. Compositional and nutritional data of fresh fruit that reflect Alabama growing conditions is limited. Commercially fully ripened kiwi fruit (Actinidia deliciosa cvs. Fitzgerald and Hayward) were compared for fruit quality (pH, TA, °Brix, °Brix/TA, and soluble sugars), and antioxidant properties; Vitamin C (reduced, oxidized, and total), Vitamin C Equivalent Antioxidant Capacity (VCEAC), ferric reducing antioxidant power (FRAP), DPPH radical scavenging activity, total phenolics, and flavonoids. In general, `Fitzgerald' ranked higher in overall fruit quality and antioxidant properties when compared to `Hayward'.
(202) Quality of Sapote Mamey Fruits Treated with Hot Water and Stored at 12 °C
Authors: Martinez-Morales Arturo , Alia-Tejacal Iran , Colinas-Leon Maria-Teresa , Lopez-Martinez Victor , Bautista Cecilio
Published: February 2019

Sapote mamey (Pouteria sapota) fruit commercialization to different markets is limited due to the fact that it is a host of the fruit fly (A. serpentina), so there is a special interest in generating a quarantine treatment protocol. In the present study, fruits from Jalpa de Mendez, Tabasco, Mexico, were harvested at physiological maturity and divided in two groups: a) fruits treated with hot water (46.1 °C) for 1 h, and b) control fruits, with no hot water treatment. Fruits were then stored at 12 °C for 7, 14, 21, and 28 days. After storage, days to ripening as well as respiration rate, ethylene production, and weight loss were evaluated for 6 days. Pulp color (ligthness, hue angle, and chroma), fruit firmness, total soluble solids and sugars, and total phenols (at the end of storage and 6 days after) were also evaluated. Results show that fruits stored for 0 days ripened in 5.8 days, while fruits stored between 7 and 28 days took between 3.2 and 5.6 days to reach the ripe stage. Considering the storage periods, effective postharvest life was increased between 11 and 32 days. Respiration rate markedly increased in control fruits after 21 days of storage, but no chilling injury symptoms were observed. Hot water treatment did not affect ethylene production, sugar or phenol content, color, and fruit firmness. Total soluble solids and sugars increased as storage period increased and even more after storage, thus suggesting that storage temperature does not stop the ripening process. No significant changes were observed in the color components. Results suggest that the hot water inmersion treatment is an alternative to reach the quarantine protocol (not affecting quality) and when combined with refrigeration could be used to sent fruit to distant places.
(138) Metabolite Profiling in Heat- and Drought-stressed Arabidopsis
Authors: Shuman Joel L. , Mittler Ron , Shulaev Vladimir
Published: February 2019

Drought and heat stress have been extensively studied in plants, but little is known about how the combination of drought and heat impact their physiology and metabolism. The metabolite profile of Arabidopsis subjected to heat, drought, and the combination of heat and drought were analyzed by gas-chromatography-mass spectrometry (GC-MS). Fatty acid retention time standards and the internal standard (IS) ribitol (adonitol) were added to each leaf sample and the polar phase was extracted, methoximated, and derivatized (trimethylsilylated) prior to analysis by GC-MS (Trace DSQ with Combi-PAL autosampler). Compounds were identified based upon retention time (relative to fatty acid standards) and comparison with reference spectra in our custom mass spectral library. Semi-quantitation of compound peak area was done relative to the internal standard. Plants subjected to both heat and drought stress accumulated sucrose and other sugars/sugar alchohols such as maltose, gulose, mannitol. The amino acid proline (Pro) was found in drought-stressed plants, but not found in drought- and heat-stressed plants. Proline has been reported to function as an osmoprotectant in cold-, salt-, and drought-stressed plants, but could be toxic to drought- and heat-stressed plants. We found that growth of heat-stressed Arabidopsis seedlings is inhibited by Pro, but not in drought- and heat-stressed seedlings. These results also indicate that sucrose replaces proline as the major osmoprotectant in heat- and drought-stressed plants. Plants subjected to combined heat and drought also exhibited enhanced respiration, suppressed photosynthesis, and distinct transcriptome expression.
(139) A Capacity for Mannitol Biosynthesis is a Critical Component of Salt Tolerance in Celery
Authors: Loescher Wayne H. , Sabbatini Paolo , Song Guo-Qing , Sink Kenneth , Flore James
Published: February 2019

Mannitol, a sugar alcohol that appears to serve as an osmoprotectant/compatible solute to cope with salt stress, is synthesized in celery (Apium graveolens L.) via the action of a NADPH dependent mannose-6-phosphate reductase (M6PR). To evaluate the abiotic stress effects of mannitol biosynthesis, we transformed celery with an antisense construct of the celery leaf M6PR gene under control of the CaMV 35S promoter. Unlike wild type (WT) celery, independent antisense M6PR transformants did not accumulate significant amounts of mannitol in any tissue, with or without salt stress. In the absence of NaCl, and despite the lack of any significant accumulation of mannitol that is normally the major photosynthetic product, antisense transformants were mostly phenotypically similar to the WT celery. However, in the presence of NaCl, mature antisense transgenic plants were significantly less salt-tolerant, with reduced growth and photosynthetic rates, and some transformant lines were killed at 200 mM NaCl, a concentration that WT celery can normally withstand. Although mannitol biosynthesis is normally enhanced in salt-treated WT celery, no such increase was observed in the antisense transformants. Like our previous gain of function results showing enhanced salt tolerance in Arabidopsis plants transgenic for a sense M6PR construct, these loss of function results, using an antisense construct in celery, demonstrate a major role for mannitol biosynthesis in developing salt-tolerant plants.
(143) Drought Acclimation of Leaf Gas Exchange in Jalapeno and Big Chili Pepper
Authors: Williams Frank , Barbarin Alexis , Hauber Donald , Ratnayaka Harish
Published: February 2019

Drought is a major constraint to chili production in a variety of cropping systems worldwide. A greenhouse study was conducted to understand mechanisms underlying drought acclimation of leaf gas exchange in two popular chili cultivars, `Big Chili' and `Jalapeno'. Unstressed `Big Chili' had 27% greater net photosynthesis (Pnet), 60% higher stomatal conductance (gw), and 18% higher transpiration (E), but only 3% greater intercellular CO2 concentration (Ci) than `Jalapeno'. Light compensation point was 43.3 and 31.6 μmol·m-2·s-1 in `Big Chili' and `Jalapeno', respectively, although light-saturated assimilation (Amax) and photosystem II efficiency (F'v/F'm) were the same in the two cultivars. Maximum rubisco-mediated carboxylation, Vcmax, was 66.3 and 69.1 μmol·m-2·s-1 in `Big Chili' and `Jalapeno', respectively. During drought, 50% of plants wilted to zero Pnet in 5 days in `Big Chili', and 7 days in `Jalapeno'. However, at wilting, relative water content was the same at 66%, with 97% less gw than unstressed plants, in each cultivar. `Jalapeno' had 9% greater F'v/F'm than `Big Chili', at wilting. Four days after rewatering, Pnet, gw and F'v/F'm were 27%, 47%, and 8% less in `Big Chili', but only 11%, 19%, and 4% less in `Jalapeno', than unstressed plants, respectively. `Jalapeno' shows greater acclimation of gas exchange to drought than `Big Chili' through rapid recovery of photosystem II, carbon assimilation and stomatal activity.
(131) E-beam Irradiation Induced Minor Changes in Phytochemical Content and Antioxidant Capacity of Pecan Kernels
Authors: Villarreal Jose E. , Lombardini Leonardo , Cisneros-Zevallos Luis
Published: February 2019

Pecans nuts from `Kanza' and `Desirable' cultivars were irradiated with 0, 1.5, and 3.0 kGy using electron beam (E-beam) irradiation and stored under accelerated conditions (40 °C and 55% to 60% RH). Antioxidant capacity (AC), phenolic (TP) and condensed tannin (CT) content, HPLC phenolic profile, tocopherol content, peroxide value (PV), and fatty acid profile were evaluated in kernels after 0, 7, 21, 55, and 134 days of storage. Irradiation had no detrimental effects in AC and TP; however, variation was found throughout storage. Tocopherol content of 1.5 and 3.0 kGy kernels decreased after irradiation, but no further decrease was observed thereafter. Irradiated `Desirable' samples had greater PV than controls, while `Kanza' 1.5 kGy samples had increased PV only after 134 days of storage. No change in fatty acid composition was detected for any cultivar. Color modification induced by storage included a decrease in lightness and yellowness and an initial increase of redness followed by a decrease after 98 days of storage. No differences in phenolic profile were observed after irradiation. Compounds identified by HPLC in hydrolyzed extracts were gallic and ellagic acid, catechin, and epicatechin. In general, beside the decrease in tocopherol content, no detrimental effects were found in antioxidant composition caused by irradiation treatments. While a faster oxidation rate was seen in irradiated kernels for `Desirable' cultivar, no other quality attribute was affected by E-beam irradiation.
(18) Is Withholding Irrigation during Winter Months Detrimental to Onion Bulb Quality?
Authors: Singh Jagtar , Cramer Christopher S.
Published: February 2019

Onion growers in New Mexico often withhold irrigation for overwintered onion varieties during the months of December and January. This study was initiated to determine if this deficit irrigation program is detrimental to onion bulb quality. Twelve short- and intermediate-day onion cultivars, which differed in their maturity, were seeded in Sept. 2004 in Las Cruces, N.M. Once plants were established, 12 plots of each cultivar were not irrigated during the months of December and January (dry treatment), while the same number of plots was irrigated during these months (wet treatment). Once a plot had 80% of the plants with tops down, all bulbs were harvested, cured, and data on date of harvesting, bulb diameter, bulb height, firmness rating, number of centers, scale number, and scale thickness of first and third fleshy layers were collected. For most of the bulb traits measured, there was no difference between the two irrigation treatments for the cultivars tested. For the earliest-maturing cultivars, bulbs grown in the dry treatment had on average more fleshy scale layers than the bulbs grown in the wet treatment. For later-maturing cultivars, bulbs grown in the dry treatment had more growing points (centers) per bulb than the bulbs grown in the wet treatment. For the latest-maturing cultivars, average fleshy scale layer thickness was greater for bulbs grown in the dry treatment. From this work, a winter deficit irrigation program appears to be detrimental to the percentage of single-center bulbs for later-maturing, autumn-sown onion cultivars.
(20) The Potential of Bacanora Plant Use in Distillation and Ornamental Industries in Sonora, Mexico
Authors: Zamora Everardo , Ayala Santiago , Guerrero Cosme , Martínez Damian , Rivas Francisco
Published: February 2019

In Sonora, Mexico, a new crop is emerging as a potential and alternative crop industry: the bacanora plant (Agave angustifolia Haw). The bacanora plant belongs to the Amaryllidaceous family and is a type of agave with a low water requirements, growing as a wild plant in Sonora, Mexico. It is different from the one used to produce the most famous Mexican liquor in the world—tequila. Some time ago, the bacanora plant had been used to distill and produce a kind of liquor known by Sonoran people as bacanora. However, this activity was prohibited by the Sonoran government during the past century. Now, in order to encourage job growth, the Sonoran government has given permission to producers for new bacanora plantations. To protect the originality of both bacanora plant production and the bacanora distillation industry, the Federal Mexican government issued a law that prohibits all activity for growing bacanora plant and bacanora distillation outside of Sonora, Mexico. The law was approved in 2005 and now, all natural areas where wild plants of bacanora grow are known as “origin denomination,” which means that some Sonoran areas are unique locations where the bacanora industry can be legally established for plant production, distillation, refining, and labeling. Currently, there are about 20,000 ha of bacanora plants located in Sonora. Some producers estimate that, in the near future, there will be more than 60,000 ha of bacanora plants. Although bacanora plants are used mainly for producing liquor, they could be considered ornamental plants for establishing home desert gardens together with desert plants, such as cacti.
(81) Effect of Ethephon on Establishment of Herbaceous Ornamentals in a Landscape—Response of Plants During Production Phase
Authors: Vyapari Sudeep , Graves Robert , Thralls Edmund
Published: February 2019

Use of growth regulators in ornamental plant production is a common nursery practice. Research conducted in determining landscape establishment of herbaceous plants treated with various concentrations of growth regulators is limited. The first phase of this study was conducted to evaluate response of three herbaceous ornamental species to application of ethephon. Containerized plants of irish moss, scotch moss, and salvia were treated once with FLOREL® (ethephon) at 0, 250, 500, or 750 ppm 2 weeks after transplanting into #1 size containers. During the course of the 6-week production period, standard nursery practices of fertigation, pest control, and weed management were followed. Data were collected on growth indices and marketable quality ratings (scale of 1–5) every 2 weeks. Mean initial and final shoot and root dry weights were calculated at the start and end of this phase of the experiment. The experimental design was completely randomized and data analyses were made using the analysis of variance with SAS general linear model procedure. Growth indices (cm) were significantly affected by increasing concentrations of FLOREL®. At 750 ppm concentration the mean growth indices were low (2516 cm) whereas, control (0 ppm) produced the highest mean growth indices (4317 cm). Significant differences in marketable quality ratings were also observed among the treatments where control (0 ppm) plants had the best mean rating (4.3) as compared with 500 ppm (3.6) or 750 ppm (3.5) concentrations. Salvia produced mean growth indices and mean width of 9106 and 513 cm, respectively. However, irish moss had asignificantly higher mean quality rating (4.4) when compared with either salvia (3.7) or scotch moss (3.3).
(82) Determining Effects of a Uniconazole Drench on Celosia, Petunia, Salvia, and Tagetes
Authors: Runkle Erik S. , Whitman Catherine M. , Olrich Mike
Published: February 2019

Uniconazole is a plant growth regulator used to inhibit internode elongation on container-grown ornamental plants. Uniconazole is effective on a wide range of plants, but is not commonly used on bedding plants because of concerns about stunting and flowering delay. Our objective was to determine the effectiveness of uniconazole when used as a drench, eliminating the variability inherent in a spray application. Seedlings of Celosia argentea L. var. plumosa L. `Fresh Look Red', Petunia ×hybrida Vilm.-Andr. `Prostrate Wave Rose', Salvia splendens Sell ex Roem. & Schult. `Vista Red', and Tagetes erecta L. `Inca II Gold' in 288-cell plug trays were transplanted 2 days after arrival into 10-cm pots filled with a soilless medium containing no bark. Plants were placed in a greenhouse with a setpoint of 20 °C and under a 16-h photoperiod provided by high-pressure sodium lamps. A single drench application of 0, 0.04, 0.07, 0.15, or 0.30 mg active ingredient/pot was made 11 days after transplant. The uniconazole drench inhibited internode elongation in these species and higher rates provided a greater degree of response. At time of flowering, the 0.30-mg uniconazole drench inhibited shoot length in Celosia, Petunia, Salvia, and Tagetes by 36%, 23% 26%, and 13%, respectively. Drenches of 0.04 or 0.07 mg provided a desirable degree of height control for Celosia and Salvia. For vigorous species like Petunia or Tagetes, 0.15 to 0.30 mg may be more appropriate. We observed a 1- or 2-day delay in flowering of Salvia and Tagetes plants drenched with 0.30 mg, but no delays in Petunia flowering.
(121) `Rubaiyat': An Old Cultivar with New Potential
Authors: Stafne Eric T.
Published: February 2019

In 2005, 212 ha of grapes were grown in Oklahoma and more than 30 licensed wineries were in operation. With this increase in grape growing and wine making comes the necessity to evaluate commercially appropriate cultivars. `Rubaiyat' was a cross between Seibel 5437 and `Bailey' made at Oklahoma State University by Herman Hinrichs in 1952. The overall genetic constitution of `Rubaiyat' (based on disomic inheritance) is 37.5% V. lincecumii, 31.25% V. vinifera, 18.75% V. labrusca, 6.25% V. rupestris, and 6.25% V. riparia. `Rubaiyat' is a dark blue-black grape that ripens in mid-August. The berries are medium-sized and round. The clusters are medium in size with a long shoulder. The vine has medium vigor and good to very good disease resistance. The juice is very dark red with about 19% sugars and tartaric acid levels of 0.63%. The wine is fruity and has good balance. A slight “foxy” flavor from the V. labrusca is sometimes evident in wine made from `Rubaiyat'. Currently, other hybrid grape cultivars such as `Chambourcin' are more popular for use as red wine varietals than `Rubaiyat'. However, in observation trials in Oklahoma, `Rubaiyat' compares favorably to `Chambourcin' in quality and may outyield it. Perhaps the greatest potential for `Rubaiyat' is as a teinturier, since it has the attribute of red flesh derived from its progenitor `Alicante Bouschet', a parent of `Alicante Ganzin'. `Rubaiyat' is not widely grown, but the potential exists for it to become an important cultivar for Oklahoma and surrounding states.
(65) Jasmonate-induced Changes in Polyphenol Oxidase, Peroxidase, and Proteinase Inhibitors in Horticultural Species
Authors: Rohwer Charles L. , Erwin John E.
Published: February 2019

Jasmonates are a class of plant hormones involved in plant defense and stress responses. For example, jasmonate-induced defense responses in Lycopersicon esculentum include increases in activity of proteinase inhibitors, polyphenol oxidases, and peroxidases. As part of our efforts to reduce or control greenhouse pest infestations, we hypothesized that methyl jasmonate (MeJA) could induce these biochemical changes in common greenhouse crops. We studied Impatiens wallerana `Super Elfin Pink', L. esculentum `Big Boy', Petunia ×hybrida `Bravo Lavendar', Viola ×wittrockiana `Imperial Beaconsfield', Coleus ×hybridus `Wizard Jade', Nicotiana alata `Saratoga Lime', Pelargonium ×hortorum `Pinto Pink', and Tagetes erecta `Antigua Primrose'. Polyphenol oxidase and peroxidase activity was studied in the first four species, and proteinase inhibitors were studied in all eight. We sprayed plants with 0, 5 × 10-6, or 10-4 molar MeJA and made measurements after 24 hours. We detected a small increase in polyphenol oxidase activity of plants treated with 10-4 molar MeJA; 5 × 10-6 molar had no effect, and L. esculentum had the highest polyphenol oxidase activity. Peroxidase activity was not affected by MeJA. I. wallerana had the highest peroxidase activity, L. esculentum and V. ×wittrockiana had the lowest. 5 × 10-6 molar MeJA increased proteinase inhibitor activity in most species, and 10-4 molar increased activity in every species except P. ×hortorum.
(255) Growth and Salt Tolerance of Grafted Hot Pepper Seedlings
Authors: Lee Hee-Ju , Lee Sang-gyu , Chun Changhoo , Lee Jung-Myung
Published: February 2019

Use of grafted seedlings is a practical method to overcome salt accumulation, deterioration of physicochemical properties of soil, and accumulation of soil-borne pathogen that farmers, as well as commercial plug seedling producers, in Korea mainly adapted. Graft-take, subsequent growth, and quality characteristics of grafted hot pepper (Capsicum annuum L.) seedlings composed of three scions and 10 rootstocks were investigated. `Manita', `Chungyang', and `Nokkwang' were cultivars of scions used—they are the major hot pepper cultivars in Korea. The ten rootstock cultivars can be categorized into three groups: cultivars specially bred for rootstocks (`Konesian Hot', `PR-380', `R-Safe', and `Tantan'); cultivars recently bred in NHRI, Korea with the potential to be rootstocks (`Wonkwang1' and `Wonkwang2'); and cultivars originally bred for fruit harvest, but used as rootstocks due to their tolerance to soil-borne pathogens (`Kataguruma', `PR-Data', `PR-Gangza', and `PR-Power'). All the plants were treated with 5 mg·L-1 diniconazole solution 2 weeks after grafting and were soaked into 1.4% salt solution for 48 hours about 5 weeks after grafting. All the grafted seedlings showed feasible growth, including normal flowering and fruit set, and any symptoms of phytophthora blight and anthracnose were not found during 17-day-long experiment. Seedlings grafted onto `Tantan' rootstock showed stronger tolerance to high salt concentration than those grafted onto other rootstocks. Use of some, such as `Wongang 1', `PR-Data' and `Kataguruma', was alleviated the salt-induced growth inhibition.
(29) Effects of Colored Plastic Mulches on Bell Pepper Yield and Fruit Characteristics
Authors: Ogutu Maurice
Published: February 2019

A study was carried out to compare the effects of different colored plastic mulches (black smooth, red, black embossed, blue, olive, yellow, clear, white, and reflective) and bare ground on bell peppers (Capsicum annum) yield and fruit characteristics. Pepper varieties `Crusader' (2004 trial) and `Boynton Bell F1' (2005 trial) seeds were planted in flats filled with Jiffy Mix in a greenhouse in late Apr. 2004 and 2005, and the seedlings transplanted in early June 2004 and 2005, respectively. In 2004, pepper fruits were harvested once in early September, and reflective and black embossed plastic mulch treatments had higher U.S. No. 1 fruit weight than other treatments. Pepper fruits harvested from reflective plastic mulch treatment were longer and larger than fruits in other treatments. In 2005, pepper fruits were harvested three times in late September to early October, and plants grown in reflective and red plastic mulch treatments had higher Fancy fruit weights while olive and white plastic mulch treatments had higher U.S. No. 1 fruit weights than other treatments. Fruits from reflective and red plastic mulch treatments were longer and larger than fruits from other treatments. The total marketable yield (Fancy and U.S. No. 1 fruit weight combined) was higher in olive, reflective, white, and red plastic mulch treatments. In comparison with black embossed plastic mulch, plants grown in reflective and olive plastic mulches had higher yield in 2004. However, in 2005, yield followed the same trend, with plants grown in olive, white, and reflective plastic mulches having higher yield than other treatments.
(168) Phospholipase Dα and Lipoxygenase Gene Expression in Fruit, Floral, and Vegetative Tissues of `Honey Brew' Hybrid Honeydew Melon
Authors: Whitaker Bruce D. , Lester Gene E.
Published: February 2019

Increases in phospholipase D (PLD) and lipoxygenase (LOX) activities are thought to play a key role in senescence of mesocarp tissues in muskmelon fruit. We have cloned and characterized two full-length cDNAs, CmPLDα and CmLOX1, encoding PLDα and LOX proteins in honeydew melon (Cucumis melo L. Inodorus Group). Levels of expression of the corresponding genes were determined by semi-quantitative RT-PCR in developing and mature fruit mesocarp tissues (20–60 d after pollination; DAP), and in roots, leaves, and stems from 4-week-old and flowers from 6-week-old plants. The coding regions of CmPLDα1 and CmLOX1 cDNAs are, respectively, 2427 and 2634 nucleotides long, encoding proteins 808 and 877 amino acids in length. CmPLDα1 is most similar to PLDα genes in castor bean, cowpea, strawberry, and tomato (77% nucleotide identity), and is the first cucurbit PLD gene cloned. CmLOX1 has 94% nucleotide identity to a cucumber LOX gene expressed in roots and 80% identity to cucumber cotyledon lipid body LOX. Transcript of CmPLDα1 was much more abundant than that of CmLOX1, but relative levels of transcript in the various organs and tissues were similar for the two genes. Expression was highest in roots, flowers, and fruit mesocarp tissues. CmPLDα1 expression in fruit was high throughout development, although maximum levels occurred at 50 and 55 DAP, respectively, in middle and hypodermal mesocarp. CmLOX1 expression was generally higher in middle than in hypodermal mesocarp with maximum transcript levels at 55 and 50 DAP, respectively. Overall, the patterns of expression of CmPLDα1 and CmLOX1 are consistent with a model in which their encoded enzymes act in tandem to promote or accelerate senescence in fruit mesocarp tissues.
Domestication of Vegetables as Illustrated in Renaissance Art
Authors: Nienhuis James
Published: February 2019

An enigma in the process of domestication of many of our common vegetables is what they looked like and the speed of the process at which they were transformed from the wild progenitors to the modern cultivars. Many vegetables were either domesticated in antiquity or introduced into Europe, often by trade with Africa, the Middle East, or the Americas. Based on genetic information, we often know or can deduce center of origin and the progenitor species of our common vegetables, but we do not have a record of their early history once introduced into Europe. One window to the process of domestication of vegetables is still life art from the Renaissance period. The emphasis of the art form “natura morta” emphasized realism, which allows us to, in some cases, identify species and market classes based on accurate morphological details.
Using Prevosti's Distance Coefficient for Direct Statistical Analysis of Population Differences
Authors: Kisha Theodore , Johnson Richard , Skinner Dan , Greene Stephanie
Published: February 2019

Three alfalfa populations were compared using four molecular marker systems. Population differences were analyzed using Prevosti's distance coefficient, which is a measurement over all loci of the proportion of unshared alleles. The variance of this sample distance is related to the genetic diversities used in calculating F-statistics and can be easily generated using a spreadsheet. The simplicity of statistical testing using Prevosti's distance, and its accuracy at small distances compared with other coefficients, are unique and useful characteristics of this measurement.
Early Season Broadleaf Weed Control in Onion
Authors: Hatterman-Valenti Harlene M. , Schumacher Carrie E. , Auwarter Collin P. , Hendrickson Paul E.
Published: February 2019

Field studies were conducted at Absaraka, Carrington, and Oakes, N.D., in 2005 to evaluate early season broadleaf weed control and onion (Allium cepa L.) injury with herbicides applied preemergence to the crop. DCPA is a common preemergence herbicide used in onion. However, DCPA can be uneconomical in most high-weed situations, or the usage may be restricted due to possible groundwater contamination. Potential substitutes evaluated were bromoxynil, dimethenamid-P, and pendimethalin. Main broadleaf weeds were redroot pigweed (Amaranthus retroflexus L.) and common lambsquarters (Chenopodium album L.). In general, all herbicides, except bromoxynil, provided acceptable broadleaf weed control 4 weeks after treatment. The highest herbicide rate provided greater weed control compared with the lowest rate for each herbicide. However, onion height was also reduced with the highest herbicide rate. In addition, the two highest rates of dimethenamid-P reduced the onion stand compared with the untreated. A postemergence application of bromoxynil + oxyfluorfen + pendimethalin to onion at the four- to five-leaf stage controlled the few broadleaf weeds that escaped the preemergence treatments and provided residual control of mid- and late-season germinating broadleaf weeds at two of the three locations. Intense germination of redroot pigweed during July at the Oakes location reduced onion yield with all treatments compared with the hand-weeded check. In contrast, total onion yields with all herbicide treatments except the high rate of dimethenamid-P were similar to the hand-weeded check at Absaraka and Carrington.
Water Potential Characteristics of Transgenic Petunias Over-expressing Two Arabidopsis C-repeat Binding Factor cDNAs
Authors: Boldt Jessica L. , Barrett James E. , Clark David G.
Published: February 2019

Petunia × hybrida `Electric Purple' plants, genetically transformed (Selecta Klemm Co.) via Agrobacterium tumefaciens to constitutively express the Cauliflower Mosaic Virus 35S promoter (CaMV35S) fused to two separate Arabidopsis c-repeat binding factor cDNAs (CBF3 & CBF4), were utilized to evaluate water relations. Non-stressed plants followed a classical stomatal conductance pattern, with maximum conductance between 1000 hr and 1400 hr. CBF3 and CBF4 plants showed an increase in transpiration rates and a decrease in stomatal resistance at 1230 hr, compared to `Electric Purple'. Transpiration rates (per unit leaf area) were similar in CBF3 and `Electric Purple' plants, but CBF4 plants were 12% less than `Electric Purple'. Xylem water potentials at visible wilt were between –1.4 and –1.5 MPa and there were no significant differences between line or irrigation treatment. A fourth experiment observed differential plant responses to stress cycles. Under non-stress irrigation conditions, CBF4 plants showed an increase in stomatal resistance and a decrease in transpiration rate compared to `Electric Purple' plants. There were no differences in the xylem water potential at visible wilt for the first and third stress cycles, but, for the second cycle, xylem water potentials at wilt were –1.9, –1.7 and –1.4 Mpa for CBF4, `Electric Purple' and CBF3 plants, respectively. CBF3 and CBF4 plants showed small differences in performance as compared to `Electric Purple' and under mild stress conditions as imposed in these experiments apparent heterologous overexpression of the Arabidopsis CBF3 & 4 transgenes may not be sufficient for conferring drought tolerance in petunia.
An Interactive Online Case Study to Improve Problem-solving Skills of Landscape Horticulture Students
Authors: VanDerZanden Ann Marie , Sandrock David R.
Published: February 2019

Horticulture graduates entering the landscape industry will be faced with a multitude of complicated management decisions where they will need to integrate their understanding of plant science, site constraints, state and federal environmental regulations, and the human impact on the built landscape. To help students develop and refine their problem-solving skills, an interactive online case study was created. The case study was used in two different landscape horticulture courses at Iowa State University and Oregon State University. The case study centers on a residential backyard with eight landscape problem scenarios. Each scenario is identified on the clickable landscape map of the area and contains links to audio files, PDF documents, images, and Internet links. After investigating each scenario, students submit an analysis, diagnosis, and recommendation about the landscape problem via WebCT or Blackboard, depending on the institution. Student evaluation of the case study as a teaching tool was positive (3.5, where 1 = poor; 5 = excellent). Students answered additional questions using a scale where 1 = strongly disagree and 5 = strongly agree. As a result of using this teaching tool, students felt that they were able to summarize the data (3.9), diagnose the landscape problem (3.9), and make a recommendation to the homeowner (3.6). Further, they felt this teaching tool was an effective way to deliver information (3.9); the interactive format aided their learning (3.7); that they were comfortable using a web-based format (4.2); and they liked learning using case studies (4.1). Our goal is to make the case-study framework available to other teaching colleagues who can then add their own data.