bluuebunny/crossref_metadata_2025 huggingface dataset:
DORMANT PRUNING INFLUENCE ON PEACH PISTIL HARDINESS
Authors: Durner Edward F.
Published: February 2019

Ethephon (100 mg·liter-1) was applied to mature peach trees [Prunus persica (L.) Batsch. cv Redhaven] on 13 Oct. 1989. Ethephon-treated and non-treated trees were pruned on 12 Dec. 1989, or left not pruned. Flower bud hardiness was assessed via exotherm analysis from Dec. through Mar. on buds taken directly from the orchard and on buds deacclimated / reacclimated under controlled conditions. Buds from ethephon-treated trees were consistently hardier than buds from non-treated trees. After a warm spell in Jan., buds from pruned trees not previously treated with ethephon were less hardy than those from non-pruned trees. Hardiness of buds from ethephon-treated trees after the warm spell was not affected by pruning. All buds rehardened with the return of low temperatures. Under controlled conditions, buds from pruned trees were less hardy than those from non-pruned trees. Pruning resulted in a rapid loss of hardiness at warm temperatures (21C). If trees had been treated with ethephon the previous fall, significant rehardening of dehardened buds from pruned trees occurred at 5 or -1C. Buds from pruned, non-treated trees did not reharden.
EFFECTS OF APPLE TREE DENSITY AND ROOTSTOCK ON YIELD AND FRUIT CHARACTERISTICS OVER 13 YEARS
Authors: Jordan Jack , Gregory E.J. , Smith D. , Benally I.
Published: February 2019

A three density-three rootstock test was conducted on three spur-type apple cultivars grown in sandy loam soil. Trees of the three cultivars: `Redspuree' (RS), `Goldspuree' (GS), and `Spuree Rome' (SR) were trained to a central leader system in a 100% grass cover. All cultivars produced best in the high density planting (1344 trees/ha.). Most consistently and significantly affected were the SR. The least productive density, the low density, had 336 trees per ha. while the medium density had 672 trees/ha. Density had a more significant effect on SR culls and a slightly more significant effect on SR fruit soluble solids than it did on these variables of the other cultivars. Density had little effect on fruit firmness of all cultivars. Of these rootstocks: m7a, m26, and mml06, the mml06 rootstock usually produced the greatest yields, especially in the RS and SR cultivars. Results for the GS were more variable than they were for RS and SR with its production on the m7a rootstock occasionally exceeding that of the mml06 rootstock. The m26 rootstock produced the lowest yields. Rootstock had no significant effect on fruit firmness of all cultivars.
SHORT-LIFE AND NON-SHORT-LIFE SOIL RATIO AND ROOT TYPE AFFECT PEACH TREE SURVIVAL IN FIELD MICROPLOT
Authors: Yadava Umedi L.
Published: February 2019

A planting of 90 Redhaven peach (Prunus persica (L) Batsch) trees either budded to Lovell and Nemaguard rootstocks or on their own roots, was established in spring 1984 using in-ground 55-gallon microplots. Planting soils (top soil, not B and C layers) prepared in five ratios by mixing soils from peach tree short life (PTSL) and non-PTSL (NPSL) sites (100% PTSL, 75% PTSL + 25% NPSL, 50% of each, 25% PTSL + 75% NPSL, and 100% NPSL) as main plots, were replicated 3 times. Two trees per rootstock were randomized within main plots. The planting was maintained using conventional cultural practices. Observations for tree survival were recorded in December each year. During this investigation, both soil mix and root types significantly affected tree survival, which was consistently the highest in 100% NPSL and the lowest in 100% PTSL soil. Effects of other soil combinations were intermediate; however, greater tree mortality was associated with increased ratio of PTSL soil. Trees on Lovell roots invariably survived the best followed by those on Nemaguard roots and the lowest when on their own roots. As early as in fourth leaf, >55% of the own-rooted trees died compared to < 10% on either rootstock.
PRELIMINAR STUDIES ON `CIMARRON' WILD PLUM AS A NEW FRUIT CROP FOR ARID LANDS
Authors: León José Luis , Troyo-Diéguez Enrique
Published: February 2019

The high cost of inputs and water deficit in arid lands demand the use of more drought tolerant species into the agricultue. The flora of the deserts offer a variety of fruits and vegetables that may diversify horticulture. `Cimarrón' wild plum tree or “ciruelo cimarrón” (Cyrtocarpa edulis Brand.:Anacardiaceae) is one of the species with potential importance in arid lands. C. edulis is an endemic tree of the meridional portion of the Baja California peninsula, occurring along arroyos and on gentle slopes in sandy soils. The flesh of the fruits is edible, with a slight acid tang, and is used locally. Actual exploitation is based on the fruit harvest in natural dry forest and xerophilous shrubs, where average density is near 100 trees/Ha. There is a growing interest in marketing the dried fruits, especially for the snack industry, hence, the need to develop a breeding program in order to establish it as a reliable fruit crop.
IS ETHYLENE ASSOCIATED WITH THE RELEASE FROM DORMANCY DURING CHILLING STRATIFICATION IN EASTERN REDBUD SEED (CERCIS CANADENSIS)?
Authors: Geneve Robert L. , Kester Sharon T. , Woods Terriawkia A.
Published: February 2019

Ethephon and ethylene gas applied to intact Eastern redbud seed induced germination in 44 or 53% of dormant seed. However, endogenous ethylene production was not found to be correlated with the release from dormancy during chilling stratification (5°C). Seeds stratified in the presence of 6000 ppm 2.5-norbomadicne germinated at the same percentage as control seeds. Isolated embryos treated with 100 to 500 μM AOA or 1000 μM silver thiosulfate germinated at a slower rate than control seeds, but the release from dormancy during stratification was unaffected by either ethylene inhibitor. Ethylene evolution, ACC and MACC content remained at a low level throughout stratification. EFE activity was not detectable in hydrated dormant or non-dormant seed. All ethylene parameters measured increased sharply during germination with peak activity correlated with radicle emergence. These data indicated that ethylene production was linked to germination, but unrelated to dormancy release in Eastern redbud seed.
EFFECT OF AN IRRIGATION SYSTEM CONTROLLED BY SOIL MOISTURE TENSION IN REDUCING WATER USAGE AND RUN-OFF IN POINSETTIA PRODUCTION
Authors: Newman Julie P. , Lieth J. Heinrich , Faher Ben
Published: February 2019

An irrigation system for monitoring and controlling soil moisture tension in the root zones of potted plants using computer and solid-state tensiometer technologies was evaluated in a commercial greenhouse on 'V-14 Glory' poinsettias over a 10 week period. Replicated benches with separate drip circuits controlled by the computer maintained the soil moisture tension of the potted poinsettia plants between 1 kPa and 5 kPa. The amount of water used by each bench and the amount leached was compared to benches with separate drip circuits that were manually operated by the grower according to standard commercial practice. There was a 65% savings in the total amount of water used for the computer-controlled system and an average weekly reduction of 98.6% in leachate. The differences were significant and there was no measurable reduction in plant quality, even though soil analyses showed slightly elevated EC levels.
THE INFLUENCE OF CONTINUOUS AND INTERMITTENT CO2 ENRICHMENT ON THE GROWTH, PRODUCTIVITY, AND PHYSIOLOGY OF GREENHOUSE TOMATO
Authors: Gagnon A. , Yelle S. , Gosselin A.
Published: February 2019

The objective of this experiment was to examine the influence of continuous and intermittent carbon dioxide enrichment on the growth of greenhouse tomato plants. Tomato plants were grown under four CO2 regimes: Control at 330 ppm, continuous supply at 1000 ppm, and intermittent supply (1h supply/2 hours) at 1000 ppm and 2000 ppm. Carbon enrichment produced an increase in photosynthetic rate and plant dry weight, a decrease in leaf nitrate level, and leaf accumulation of reducing sugars and starch. A loss in efficiency was observed over time in plants grown under high atmospheric C02 concentration. However, intermittent carbon enrichment reduced the plant acclimation. Even with 32% less C02, intermittent enrichment at 1000 ppm produced yields 6% greater than continuous enrichment. The superior yield may be explained by preferential allocation of photosynthates to the fruit under intermittent supply.
EFFECTS OF HIGH-PRESSURE SODIUM AND METAL HALIDE SUPPLEMENTAL LIGHTING ON GROWTH, YIELD AND GAS EXCHANGES OF VEGETABLE CROPS
Authors: Charbonneau J. , De Y. , Demers D.-A. , Dorais M. , Gosselin A.
Published: February 2019

The objective of the experiments was to compare the performance of metal halide (MH) and high-pressure sodium (HPS) lamps on growth and yield of vegetables. Four experiments with lettuce were carried out. The lettuce grown under HPS lamps had a head firmness higher than under MH lamps. The difference between the type of lamps on fresh weight was not very constant with the period of production. There was no interaction between lamp and cultivar. Two experiments were carried out with tomato in Spring and Fall 1991. For a tomato crop, the yield and quality of the fruit were not affected by the type of lamps. Photosynthesis and transpiration of tomato and pepper plants were measured under MH and HPS lamps. No significant differences were found between both lamps under two humidity conditions and four PPFs. Under high humidity conditions, transpiration under MH was higher than under HPS.
EFFECTS OF HYPOCOTYL MORPHOLOGY ON SURVIVAL RATIO AND GROWTH OF CUCUMBERS GRAFTED ON Cucurbita spp. AT HYPOCOTYL
Authors: ODA M. , Tsuji K. , Ichimura K. , Sasaki H.
Published: February 2019

Horizontal grafting, in which scion and rootstock are cut and grafted horizontally at the hypocotyls, is essential for mechanization of grafting. The present studies have been conducted to improve the survival ratio and the growth of cucumbers grafted on Cucurblta spp. through horizontal grafting at the hypocotyls. The survival ratio of `Nankyoku 2' (Cucumis sativus) which had six vascular bundles at the hypocotyl was different when it was grafted on `Unryuh' or 'Kongoh' (C. moschata), six vascular bundles. The survival ratio of the scion grafted on `Dairoku' (C. maxima) which had twelve vascular bundles was the lowest. It was found that the survival ratio inversely correlated with the difference in the diameters of the hypocotyls of the scion and the rootstock. Fresh and dry weights of survival scions on `Unryuh' and `Kongoh' were almost same and heavier than that on `Dairoku'. It is suggested that minimizing the differences in the diameters and the numbers of the vascular bundles of the hypocotyls between the scion and the rootstock promotes the survival ratio and the growth of cucumbers which are horizontally grafted on Cucurbita spp..
DIFFERENTIAL FEEDING PREFERENCE OF LEAFMINER ON FOUR COS LETTUCE CULTIVARS
Authors: Nagata Russell T. , Nuessly Gregg
Published: February 2019

Damage due to leaf mining by Liriomyza trifolii (Burgess) is a major problem in many leafy vegetables, especially lettuce. A hierarchy of feeding preference of leafminer on lettuce, Lactuca sativa L. cultivars 'Valmaine', `Parris Island Cos', `Floricos 83', and `Tall Guzmaine' was determined. Leafminers were given a choice of two plants. Observations on the number of times that leafminers probed the leaf surface to feed or oviposit in each plant was counted. `Tall Guzmaine' was significantly preferred in all combinations. Probe ratio of `Tall Guzmaine' verses the other cos lines ranged from 4:1 to 90:1. There were no significant difference between the other three lines, although `Valmaine' had the lowest count in most cases. Based on the pedigrees of the cultivars tested, the observed preferences appears to be under genetic control.
CHARACTERIZATION OF NEW SPECIALTY SOYBEAN GERMPLASM FROM CHINA.
Authors: Rangappa M. , Floyd McArthur , Sapra Val , Joshi Jagmohan , Carter Thomas , Reddy M. R.
Published: February 2019

A USDA/OICD sponsored agricultural research team visited the Republic of China (Taiwan) and the People's Republic of China (PRC) in 1990 to gather information regarding soybean utilization and to increase genetic diversity of the soybean crop through new germplasm collections. A total of 25 new soybean accessions were collected and brought to the Virginia State University, Petersburg, VA, one of the OICD sponsored team participants. In accordance with the U.S. policy on the New Germplasm Collection, part of the seed of each accession was sent in original packs to USDA Soybean Germplasm Collections, University of Illinois, Urbana, Ill. Limited seed increase was done in the greenhouse and one 10m long observational row of each accession was grown at VSU Research Station in 1991. Seed traits, plant agronomic characteristics, insect pest, and disease pathogen reactions were observed and documented. Chemical analysis for nutritional quality, antinutritional factors, and biochemical components of green seeds and pods at R-7 stage and mature seeds of each accession are underway and those values will be compared with existing commercial cultivars, advanced breeding lines, and plant introductions.
TAXONOMIC STUDIES ON CULTIVATED AND KOREAN NATIVE GENUS PYRUS PLANTS BY MULTIVARIATE AND ISOZYME ANALYSIS
Authors: Ko Kwang-Chool
Published: February 2019

Fifty nine morphological characters and isozyme band patterns of glutamate oxaloacetate transminase, peroxidase, glucose phosphate isomerase from fully expanded leaves were used for taxonomic study on 51 taxa consisted of Korean native and principal cultivars of the genus Pyrus. Taxonomic relationships were analyzed by complete cluster analysis method based on Euclidean taxonomic distance of IBM PC SPSS/PC+(ver. 3.0). Among the 39 qualitative morphological characters, a great deal of variations among 51 taxa were observed in immature fruit shape, skin lusterness, hair density on pedicel, anther color, shape of leaf apex and base, hair density on leaf surface, and leaf margin. Considerable variations were found in most tested quantitative characters except in the number of petals and styles. More reliable taxonomic results could be obtained by comparing morphological characters rather than examining isozyme band patterns. Even though there were considerable differences depending upon the methods of investigation, classification of the genus Pyrus by using isozyme band patterns was proved to be a good tool for rapid taxonomic studies.
SOIL pH AND MOISTURE EFFECTS ON VEGETABLE AMARANTH PRODUCTION
Authors: Singh Bharat P. , Whitehead Wayne F.
Published: February 2019

The effect of soil moisture and pH levels on the vegetative growth of amaranth were studied in the greenhouse during 1990-91. Three soil pH levels: 4.5, 5.3, and 6.4 and four soil water levels: 3, 6, 12 and 18% (w/w) comprised the treatments of the two studies. The plants grown in pH 6.4 were significantly taller and had greater leaf area than plants grown in pH 5.3 or 4.7 soil. There was a significant decrease in all above ground plant parts with each increase in soil acidity. The top fresh weight of plants grown in 5.6 and 4.7 pH soil were 27% and 73% lower, respectively, than plant grown in 6.4 pH soil. Plant grown in 3% soil water had significantly lower leaf, stem and root fresh weights than other soil water levels. There was no significant difference in the performance of plants grown in 6, 12 or 18% soil water, suggesting that amaranth plant is adapted to a wide range of soil moisture conditions.
ACCUMULATION AND METABOLISM OF CARBOHYDRATES IN MARIGOLD SEEDLINGS
Authors: Buxton Jack W. , Switzer Donna , Hou Guoqiang
Published: February 2019

Marigold seedlings, 3 weeks old, were grown in natural light growth chambers at 3 day/night temperature regimes, 8°N/16°D, 13°N/20°D and 18°N/24°D, in a factorial combination with ambient and 1000-1500 ppm CO2. Seedlings were harvested at regular intervals during a 24 hr period and were analyzed for soluble sugars (reducing sugars and sucrose) and starch. Neither temperature nor CO2 concentration affected the accumulation of soluble sugars or starch during the day or night. The soluble sugar concentration ranged from 3% of dry weight at sunrise to 6% at mid-day; the concentration changed little during the night. Light intensity was different during replications of the experiment. Increased light intensity appeared to cause a slight increase in the soluble sugars maintained by the seedling during the day. Accumulated starch increased 6% to 8% from sunrise to late afternoon. Preliminary results indicate that light intensity greatly affected the concentration of starch. On the higher light intensity day, starch accumulated to a maximum of 18% of dry weight; whereas on the lower light intensity day the maximum concentration was 10%. During the night following the lower light intensity day, the starch concentration decreased to approximately 3% by the end of the night; following a brighter day the starch content was 13% at the end of the night.
INFLUENCE OF SPECTRAL FILTERS ON LEAF PIGMENTS AND ANATOMY OF `SPEARS' CHRYSANTHEMUM
Authors: McMahon Margaret J. , Kelly John W.
Published: February 2019

`Spears' chrysanthemums were grown in chambers fitted with double-walled exolite filled with spectral filtering solutions: a blue textile dye that absorbed red light, CuSO4·5H2O that absorbed far-red light, and H2O that was spectrally non-selective (control).

Leaves of `Spears' grown under CuSO4-filters had increased chlorophyll a (23%), chlorophyll b (26%), xanthophyll (22%), and β-carotene (24%) compared to plants grown under H2O or blue-dye filters. Ratios of total carotenoid: chlorophyll and chlorophyll a: chlorophyll b were not affected by filter.

Individual leaf area was reduced 25% under CuSO4 filters compared to other filters. Stomates per unit area were not affected by filters, however stomates per leaf were reduced 25% under CuSO4 filters because of leaf size reduction. Stomate length and width were not affected by filter. Leaves from plants grown under CuSO4-filters had an internal structure resembling that of sun-type leaves. Other filters induced a shade-type leaf.
EFFECT OF PLANTING DATE, PINCHING, AND PLANT DENSITY ON QUALITY AND YIELD OF FIELD-GROWN GODETIA
Authors: Anderson Robert G. , Geneve Robert L.
Published: February 2019

Different planting dates, plant densities and pinching practices were used to determine the production practices that produced the best quality cut stems from field grown godetia under Kentucky conditions. Godetia `Grace Salmon' transplants were planted at a plant density of 40 plants m-2 on Mar 23, Apr 8 and Apr 23, 1991 in ground beds with black plastic mulch. All plants flowered in early to mid June, but plants from the Mar 23 planting date had the highest yields of commercial quality stems (387 stems m-2) and over 80% of the stems were longer than 55 cm. In a separate experiment, transplants of `Grace Red' and `Grace Rose Pink' were planted on April 5 at plant densities of 4.5 m-2 (unpinched), 10 m-2 (soft pinch on May 1) and 23 m-2 (hard pinch on May 1). Pinching treatments were used to increase the number of secondary and tertiary branches on each plant. Although the pinching treatments produced more branches, a low percentage of the branches were commercial quality cut stems.
THE EFFECT OF TEMPERATURE ON CARBON GAIN IN ALSTROEMERIA
Authors: Leonardos E.D. , Tsujita M.J. , Grodzinski B. , Blom T.J.
Published: February 2019

Leaf and whole plant gas exchange (net photosynthesis Pn, dark respiration Dr, transpiration Tr, and resistance R) of `Jacqueline' Alstroemeria, grown in pots inside a greenhouse, were measured under lab conditions using an openflow and a semi-closed system respectively.

Temperature responses of apical fully expanded leaves, on flowering and non-flowering shoots, showed an optimum range for net photosynthesis (Pn) from 15 to 20 °C. Above 25 °C Pn dropped considerably as temperature increased. Leaf transpiration rates over the same range of temperature showed a similar decrease, indicating that low leaf Pn rates at higher temperatures were due in part to increased stomatal resistance.

Whole plant photosynthetic response to temperature was similar to that of leaf gas exchange. The optimum temperature range for whole plant Pn was from 12 to 17 °C. These results show that moderately low temperatures are essential for carbon assimilation and efficient water use in Alstroemeria. Temperature interactions with other environmental factors will also be presented in models describing Pn rates as a function of irradiance, CO2 concentration, and temperature.
THE MICROCLIMATE IN A HAWAIIAN ANTHURIUM SHADE HOUSE
Authors: Graser Elizabeth A. , Xia Haifeng
Published: February 2019

The microclimate in anthurium shade houses, which has not been previously studied, has been hypothesized to contribute to the development of anthurium blight and is important for flower production. The magnitude and spatial and temporal distribution of temperature and other conditions were measured at eight locations inside and upwind of a 3.5 ha, uniform, level, commercial shade house near Pahoa, Hawaii for two months. The energy balance was measured occasionally during this time by eddy correlation to allow explanation of the prevailing conditions. Daytime temperatures in the shade house are elevated over outside temperatures with the greatest magnitudes of about 2 to 4°C being associated with high solar radiation and low winds; nighttime temperatures are lower in the house. Conditions at the upwind edge of the house resemble outside conditions less than 40 m into the house. A temperature inversion inhibits convective exchange in the house.
WALLA WALLA SWEET ONION STORAGE AND SHELF LIFE
Authors: Mikitzel Loretta J. , Patterson Max E , Fellman John K.
Published: February 2019

Walla Walla Sweet onions (Allium cepa L.) have a short storage and marketing season. Studies to determine viable shelf life and to extend post-harvest life with controlled atmosphere (CA) storage were conducted. Onions were exposed to various CA gas mixtures in combination with heat curing (35°C) and/or chlorine dioxide (ClO2) fumigation, to control disease. Preliminary results indicated Botrytis was the primary cause of post-harvest losses. A 1% O2, 5% CO2 atmosphere appeared to maintain onion quality better than other gas mixtures tested during 15 weeks of CA storage (0°C). Carbon dioxide series above 5% show promise in reducing the 35% storage loss that occurred with the 5% CO2 treatment. Curing for at least 72 hours followed by a 1-hour ClO2 fumigation resulted in the least bulb decay and after 15 weeks of storage (1% O2, 5% CO2), 75% of the bulbs were in marketable condition. Onions stored 15 weeks in air (0°C, 70% RH) were unmarketable. Shelf life of freshly harvested onions was 18 days, after which the onions rapidly decayed. After CA storage, shelf life was reduced to 10-14 days due to rapid sprouting. To enjoy a 30-day market window, disease control is necessary for freshly harvested onions and sprouting must be controlled in post-storage onions.
LIMITATION TO THE USE OF ELECTRICAL CONDUCTIVITY FOR THE MEASUREMENT OF CHILLING INJURY IN TOMATO FRUIT
Authors: Côté France , Willemot Claude
Published: February 2019

Five tomato cultivars were tested for tolerance to chilling. After exposure of varying times to chilling at 3 °C, the fruits were returned to ambient temperature for development of chilling injury (CI) symptoms (uneven ripening and pitting). Ripening was assessed by measuring carotenoids. Electrical conductivity (EC) of leachate from pericarp discs, an indirect measure of membrane damage, was used to determine CI. During chilling EC greatly increased in the three sensitive cultivars, but hardly in the tolerant ones, in good correlation with the development of CI symptoms after rewarming. However, this correlation broke down after returning the fruit to 20 °C. While slightly injured fruit showed a large increase in EC, surprisingly EC was drastically reduced in the extensively injured fruit. Calcium pectate production due to cell wall degradation may explain the lack of correlation between EC and CI after rewarming. We conclude that EC is not always a reliable measure of membrane damage.
WATER JET TECHNOLOGY AND SALT TREATMENT USED FOR CARROT STICKS.
Authors: Tatsumi Yasuo , Watada Alley E. , Ling Peter P.
Published: February 2019

Water jet technology to slice carrots or salt treatment prior to slicing was studied to minimize the unappealing whitish tissue noted with carrot sticks. The water jet was a fine stream with 378,950 kPa force. Salt treatment consisted of immersing carrots in NaCl solution ranging from 0.0 to 1.0 M concentration for 3 to 20 hours. Subsequently, the carrots were sliced, stored at 5 C, and analyzed. Carrot sticks sliced with the water jet had a greater amount of white tissue than those sliced with a knife. Scanning electron microscopy showed that the water jet caused grooves on the cut surface, which exposed many layers of cells to dehydrate rapidly. The grooves probably can be minimized by increasing the speed of slicing. Salt treatments of 0.5 to 1.0 M concentration caused 3 to 10 percent weight loss when treated for 20 hours at 5 C or 3 hours at 20 C. Carrot sticks with increased weight loss had less whitish tissue and had an appearance of freshly cut sticks; however, the textural quality decreased.
UNICONAZOLE AND REDUCED IRRIGATION AFFECT POSTHARVEST PERFORMANCE OF CHRYSANTHEMUM
Authors: Schuch Ursula K.
Published: February 2019

Eight-week-old potted chrysanthemum (Dendranthema grandiflora Tzvelev. c. Ovaro) plants were treated with a soil drench of 0 or 2.5 mg uniconazole per liter and irrigated daily with 350 or 250 ml of nutrient solution. Plants were frequently water-stressed during their development. At the beginning of anthesis treatments were split and transferred to chambers with 20C/24 hr photoperiod or 25C/dark conditions. Anthesis progressed at the same rate in the two postharvest storage conditions, regardless of previous treatments. Plants were not watered until wilting, which was observed first in control plants under continuous photoperiod (8 days) and last in uniconazole-treated plants in dark storage (12 days). During the first 6 days in storage, evapotranspiration (ET) was lower for plants grown with 250 ml daily irrigation. From day 8 to day 12, when most plants were irrigated after they had wilted, ET was affected by uniconazole and an interaction of uniconazole and storage conditions.
STUDIES ON RHAMNOGALACTURONASE IN FRUIT
Authors: Kim Jongkee , Gross Kenneth C.
Published: February 2019

Rhamnogalacturonase (RGase) is a new fungal enzyme which degrades the highly branched regions of apple fruit cell wall pectin by cleaving the glycosyl linkage between rhamnosyl and galacturonosyl residues (Schols et al., 1990. Carhohydr. Res. 206:105.). This enzyme, if present in fruit, could play a significant role in fruit softening. Partial purification of RGase was accomplished from a fungal enzyme preparation (Pectinex Ultra SP-L, NOVO Ferment) produced from Aspergillus niger. The crude enzyme hydrolyzed chelator-soluble pectin from red ripe tomato fruit. Methylation linkage analysis of the product suggested that an increase in terminal-rhamnosyl residues accompanied pectin hydrolysis, indicative of RGase activity. Cross-linked alginate, hydroxyapatite, and DEAE-Sephadex chromatography were used to partially purify RGase. Polygalacturonase was efficiently removed using the alginate column. Crude pectin obtained from mature-green tomato fruit cell wall by extracting with 0.5 M imidazole buffer (pH 7) and 50 mM Na-carbonate was incubated with pure polygalacturonase and the residue hydrolyzed with 0.1 N trifluoroacetic acid. This modified pectin was used as a substrate to investigate the presence of RGase in tomato and other fruit.
PECTIN OLIGOMERS - POTENTIAL ENDOGENOUS REGULATORS OF RIPENING?
Authors: Melotto Eunice , Greve L. Carl , Labavitch John M.
Published: February 2019

Acid hydrolysis-generated pectic oligomers have been shown to affect ripening of tomato fruit by inducing both acceleration of reddening and increased ethylene biosynthesis (Campbell & Labavitch, 1991 Plant Physiol 97:706-713). In the present work, homogeneous size classes of these oligomers were demonstrated to have different impacts on ethylene production of tomato fruit pericarp discs. Endogenous oligomeric material of the same size classes was isolated from ripening tomato tissues and also tested for biological activity. They promoted some aspects of ripening as shown by increased ACC and ethylene production, which suggests that pectic oligomers are potential regulators of the ripening process in tomatoes. A metabolic origin for these oligomers is suggested by the fact that they are produced by in vitro polygalacturonase I treatment of polygalacturonic acid or tomato pectin.
DIURNAL PHOTOSYNTHESIS AND STARCH DEPOSITION IN LEAVES OF FRUITING AND DEFLOWERED RED RASPBERRY CANES
Authors: Klauer Stephen F. , Chen Chuhe , Foote Paul W. , Cameron J. Scott
Published: February 2019

On four dates during the 1991 growing season, gas exchange rates were measured on the same middle leaflets every 3 h from 7am-10pm from deflowered (DF) and fruiting (F) red raspberry (Rubus idaeus L. cv. “Meeker”) canes. Concurrently, the adjacent side leaflets were sampled for anatomical starch determination. The dates corresponded to the late anthesis/early green fruit, early red fruit, late red fruit, and post fruit maturity stages of the growing season. For all dates, CO2 assimilation (A) was highest from 7-10am, lowest at 4pm, and increased at 7pm. Overall A peaked during fruit development. Leaves of F canes had greater A than leaves of DF canes during fruit development, but rates were similar after fruit maturity.

Starch accumulation in leaf cross-sections generally followed the diurnal pattern observed for A. Starch appeared heaviest from 7am-lpm and often showed an increase from 7-10pm. Leaves from DF canes generally had a greater accumulation of starch. Seasonally, leaf starch from F canes appeared greatest at late anthesis, decreased during fruit development and was very low post fruit maturity. Leaf starch in DF canes appeared greatest at the late anthesis and late red fruit stages.

DF leaves had greater dry weight accumulation than F leaves during the red fruit stages. A Western blot showed that Rubisco levels as a percentage of total soluble protein were higher during fruit development and decreased after fruit maturity.
PHOTOSYNTHESIS AND CARBOHYDRATE PARTITIONING IN CRANBERRY.
Authors: Hagidimitriou Marianna , Roper Teryl R.
Published: February 2019

Fruit set has been shown to be a major limiting factor in cranberry (Vaccinium macrocarpon Ait.) productivity. Total nonstructural carbohydrate (TNC) content is lowest during the flowering and fruit set period. This research was undertaken to determine the potential sources of carbohydrates which are important to support fruit set and fruit growth in cranberry. Fruiting uprights had lower TNC content than vegetative uprights beginning at early bloom and continuing through harvest, largely due to lower starch content. Starch from fruiting uprights is apparently remobilized to support flowering and fruit set. This also suggests that uprights on which the fruit are borne are the primary source for carbohydrates for fruit set and fruit growth throughout the season. Net CO2 assimilation rates (NAR) were measured in the field on current season and one year old leaves on cranberry uprights. New leaves had higher NAR than one year old leaves throughout the season. Thus, newly formed leaves on uprights, appear to be an important source for carbohydrates for fruit set and fruit growth. On a diurnal basis NAR peaked at approximately 9:00 a.m. and gradually declined through the day.
SEASONAL CHANGE IN COLD HARDINESS AND DAYS TO BUDBREAK OF RUBUS IDAEUS L. `CHILCOTIN', `CHILLIWACK', `MEEKER', AND `WILLAMETTE'
Authors: Moore Patrick P. , Hummel Rita L.
Published: February 2019

Days to bud break and freezing tolerance of `Chilcotin', `Chilliwack', `Meeker' and `Willamette' red raspberry were measured during the 1990-1991 winter and at monthly intervals from mid-September 1991 through mid-March 1992. Canes were harvested from the field and cut into two-bud samples which were either frozen in laboratory tests or held with cut stem ends in water in a controlled environment chamber and monitored daily until bud growth was observed. Viability was estimated by visual browning after exposure to controlled laboratory freezing treatments. In general, freeze test results indicated `Meeker' and `Willamette' were not as hardy as `Chilliwack' and `Chilcotin' in late fall and midwinter but retained their hardiness longer in spring. Results for 1990-1991 indicated the greatest delay in days to bud break occurred in midwinter.
DROUGHT STRESS ALTERS BIOGENESIS OF APPLE LEAF VOLATILES
Authors: Ebel Robert C. , Mattheis James P. , Buchanan David A.
Published: February 2019

Potted apple trees were severely (S) or moderately (M) droughted and compared to a well-watered control (C) to determine changes in biogenesis of leaf volatile compounds. Total available water (TAW) of the soil was allowed to decline to near 0% TAW, 20% TAW, and 100% TAW, for S, M and C, respectively, by the end of a two-week drying period. Twenty-nine volatile compounds were identified by GC-MS using headspace sampling of detached leaves. Concentrations of (E)-2-hexenal, (E)-2-hexenyl acetate, l-hexanol, (E)-2-hexen-1-ol and hexyl acetate were 5 to 310 times higher for S than C. It is suggested that the large drought induced increase in C-6 compounds was related to enhanced lipoxygenase activity.
SEEDLING EMERGENCE AND GROWTH OF THREE CITRUS ROOTSTOCKS UNDER SALT STRESS
Authors: Zekri Mongi
Published: February 2019

Salt tolerance of Carrizo citrange (CC), sour orange (SO), and Cleopatra mandarin (CM) rootstocks during seedling emergence (SE) and early seedling growth (SG) was studied under greenhouse conditions. Increasing salt (NaCl + CaSO4) concentration delayed and emergence, reduced SG, but did not affect emergence spread. At the first salinity level (5 mmol), emergence of the first seedling (EFS) was delayed by 2 to 3 days in CC and one day in SO but was not affected in CM. At the highest salt level (80 mmol), EFS was delayed by up to 6, 7, and 5 days for CC, SO, and CM, respectively. At the two lowest salinity levels (5 and 10 mmol), final percent emergence (FPE) was not affected in CC but was reduced in SO and CM while shoot biomass was reduced in CC but was not affected in SO and CM. At the 80 mmol salt level, FPE was reduced by 23% in CC and by 33% in SO and CM while SG was reduced by 70% in CC and by 60% in SO and CM. Among the rootstocks studied, the delay in emergence was not necessarily more salt sensitive than FPE. However, SG was generally more affected by salinity than SE, particularly at high salinity levels (20, 40, and 80 mmol).
LETTUCE SEEDLING RESPONSE TO DETERGENTS RECOMMENDED FOR SPACE TRAVEL
Authors: Greene Catherine , Bubenheim David , Berry Wade
Published: February 2019

Water contributes approximately 90% of the life support consumables in a closed space environment, therefore, regeneration of pure water from waste streams is important for long term space travel. Controlled Ecological Life Support Systems (CELSS) will rely on plants to produce food, oxygen, consume CO2 and purify water. Igepon TC42, Amide coco N-methyl N-2-sulphoethyl sodium salt, is the main ingredient of the soap recommended for showering and hand washing aboard Space Station Freedom. To determine the soap concentration which causes plant toxicity, lettuce seeds were germinated in 0.1 strength modified Hoagland's nutrient solution and a series of increasing concentrations of Igepon. After 5 days, the seedlings were examined and primary root length measured. The dose response curve indicates an Igepon acute toxicity threshold of 0.2 g l-1 Below the threshold concentration the curve is similar to that of the control, but drops linearly upon reaching the toxic threshold. Seedlings exposed to concentrations of soap greater than the toxic threshold exhibited root damage characterized by the browning of cells in bands above the root cap resulting in reduced growth rates. The damaged cells enlarged becoming round in appearance prior to departing from adjacent cells. The underlying cells appeared clear and uniform making up a thinner, more fragile root mass when compared to undamaged root regions.
LOCALIZATION OF PECTINS IN XYLEM RAY CELLS OF WOODY PLANTS.
Authors: Wisniewski Michael , Davis Glen , Bowers Katherine
Published: February 2019

Our previous research has indicated that the pit membrane regulates deep supercooling of xylem parenchyma in woody plants. This area of the cell wall is composed of three layers that may be rich in pectins. Since pectins may define the porosity of the cell wall they may also regulate deep supercooling. The present study examined pectin distribution in ray cells using monoclonal antibodies, that recognize un-esterified (JIM5) and methyl-esterified (JIM7) epitopes of pectin, in conjuction with immunogold electron microscopy. Antibodies were obtained courtesy of J. Paul Knox, John Innes Inst., U.K. Dormant and non-dormant tissues of Prunus persica, Cornus florida and Salix babylonica were utilized. Labelling with JIM7 revealed that methyl-esterified pectins were abundant and evenly distributed within the primary cell wall and amorphous layer. Labelling with JIM5 revealed that un-esterified pectins were located specifically within the pit membrane, in the outer region of the primary cell wall. No differences were observed between species, however, preliminary data indicated that JIM5 labelling was greater in dormant than in non-dormant tissues.
EFFECTS OF SULFATE SALINITY AND SELENIUM TOLERANCE OF PLANTS ON SELENIUM ASSIMILATION IN WHITE CLOVER AND TALL FESCUE.
Authors: Wu Lin , Huang Zhang Z.
Published: February 2019

Substantial difference of selenium tolerance was found between the tall fescue (Festuca arundinacea Schreb.) and white clover (Trifolium rapens L.) An inverse relationship between Se accumulation and Se tolerance suggests an exclusion mechanism that restricts Se uptake by the plant with greater Se tolerance. A positive relationship between the increase of protein Se concentration and growth inhibition in the plants suggests that assimilation of Se into protein is responsible for the reducing Se toxicity at the protein level. No evidence of a Se exclusion mechanism which exclude Se from incorporating into protein plays any major role of Se tolerance in this two species.
AMELIORATION OF CHILLING INJURY IN PHASEOLUS VULGARIS BY GLK-8903.
Authors: Flores-Nimedez Agnes A. , Li Paul H. , Shin Charles C.
Published: February 2019

Protection mechanism of a new compound, coded as GLK-8903, from chilling injury in bean plants was assessed by measuring several physiological parameters. The decline in leaf water potential caused by the chilling exposure to 4°C (day/night) was minimized when GLK-8903 was applied to the plants as compared to the non-treated control. Chilling causes an increase in electrolyte leakage, an indication of chilling injury that occurs at the site of plasma membrane. An increased electrolyte leakage was reduced in the GLK-8903-treated plants during chilling. Data from plasmolysis and deplasmolysis studies of epidermal cells suggest that GLK-8903 is able to stabilize the plasma membrane under stress condition by determining the permeability coefficients plasmometrically (1.96 cm s-1 × 10-4 for GLK-8903-treated plants vs. 4.00 for the controls 3 d at 4°C) with less decreased activity of the plasma membrane ATPase (9.36 μmol ATP.mg chl-1·h-1 for GLK-8903-treated plants vs. 5.04 for the controls 3 d at 4°C). GLK-8903 appears to have high application potential in protecting bean plants from chilling injury with improved yield.
TETRASOMIC INHERITANCE OF ISOZYME AND PHENOTYPIC MARKERS IN ALLOTETRAPLOID BLUEBERRIES
Authors: Wenslaff Timothy F. , Lyrene Paul M.
Published: February 2019

A study was done to test whether inheritance is tetrasomic or disomic in tetraploid Fl hybrids between 2x Vaccinium elliottii Chapm. and 4x V. corymbosum L. Seventeen Fl hybrids derived from V. elliottii homozygous for recessive anthocyanin deficiency (AD) were confirmed by isozyme analysis and, where V. elliottii was the seed parent, by the presence of anthocyanin. Fertile hybrids with high pollen stainability were assumed to be 4x and duplex for the AD allele, having arisen from 2n gametes in V. elliottii. In nine Fl × Fl crosses, all progeny populations segregated for AD phenotype at or above the expected tetrasomic ratio of 1 AD:35 normal; no AD would be expected with disomic inheritance. Tetraploid AD progeny were used in testcrosses on sixteen Fl hybrids in 1991. Progeny segregated tetrasomically, 1 AD:5 normal. Isozyme loci PGD-2 and PGI-2 also segregated tetrasomically.
GENETIC TRANSFORMATION OF ROSE (ROSA SPP) USING THE BIOLISTIC PROCESS.
Authors: Strefeler M. S.
Published: February 2019

Genetic transformation of cut roses may greatly facilitate cultivar improvement programs by shortening the time required to introduce new genes into elite germplasm. The biolistic process offers a very promising method for the genetic transformation of roses.

The biolistic process uses high velocity mircoprojectiles (gold or tungsten) to carry foreign DNA into cells. This process has been shown to be useful for genetic transformation of many organisms. The first step in taking advantage of this process is to optimize the factors which affect transformation efficiency.

Several factors that have a significant affect on transformation efficiency were examined in an effort to optimize the biolistic process for gene transfer in roses. The factors examined were type of tissue (leaf segments, petioles, callus, etc), bombardment distance, the number of bombardments, DNA construct and microcarrier velocity.

The reporter gene, GUS, was used for determining transformation efficiency in this study. GUS was carried on several plasmid constructs which also contained antibiotic resistance (kanamycin or streptomycin. Efficiency of gene transfer was determined by calculating the number of transiently expressing GUS cells for each combination of factors.

Results of this study will be discussed and summarized.
RANDOM AMPLIFIED POLYMORPHIC DNA (RAPDs) DETECTS PATTERNS OF GENETIC DIVERSITY IN DIPLOID MUSA ACUMINATA COLLA
Authors: Jarret Robert L.
Published: February 2019

Patterns of diversity among thirty diploid clones of banana (Musa acuminata Colla.), collected in Papua New Guinea and the surrounding islands between 1987 and 1989, were examined genetically using the polymerase chain reaction (PCR) and random primers, to detect random amplified polymorphic DNA (RAPDs). PCR products were visualized on ethidium bromide stained agarose gels. Twenty of 60 random primers examined detected RAPDS in CTAB-extracted genomic DNA. Banding patterns ranged from very simple (1 or 2 bands/gel) to very complex (more than 20 bands/gel). All 30 Musa clones were distinguishable from each other based on their unique RAPD banding pattern. Principal component analysis (PCA) revealed several clusters of closely related clones within the materials examined. However, these clusterings were not correlated with either the geographic origin or the morphological characteristics of the clones. A role of the use of RAPDs in germplasm characterization is discussed.
EFFECT OF VIR GENE INDUCERS ON GENETIC TRANSFORMATION FREQUENCIES OF SWEET POTATO AND GARDEN EGG PLANT
Authors: Blay Essie T. , Porobo-Dessai Anant , Prakash C. S.
Published: February 2019

Explants of sweet potato (Ipomoea batatas) and garden egg plant (Solanum integrifolium) were cocultivated with disarmed strains of Agrobacterium tumefaciens containing binary vectors with gusA, gusA-nptll fusion or gusA-intron genes. We examined whether the addition of vir gene inducers during cocultivation would improve the transformation in both crops. Acetosyringone and galacturonic acid were tested individually and in combination. A very high GUS expression was detected histochemically in both plant species. The frequency and extent of transformation varied with the type of explant, petioles being the most responsive. The presence of the vir inducing substances in the medium influenced the percent explant area transformed but did not appreciably affect the frequency of transformation. The selective proliferation of the transformed tissue and organogenesis was achieved by the culture of explants on MS medium supplemented with antibiotics.
POLYMORPHISMS OF RAPD MARKERS IN CELERY CULTIVARS
Authors: Yang Xiaofeng , Quiros Carlos F.
Published: February 2019

Celery cultivars (Apium graveolens var. dulce) in North America have a narrow genetic base. Twenty-two celery, one celeriac and one annual cultivar were screened for polymorphic RAPD (Random Amplified Polymorphic DNA) markers with 28 arbitrary 10-mer primers. Among the total 231 bands obtained, 28 (12%) of the bands were polymorphic among the 24 accessions screened, but only 18 (7.8%) were polymorphic within the 22 celery cultivars. These markers are sufficient to distinguish each of the cultivars used. The average number of marker differences is 6.2 between two celery cultivars, 13.5 between the celeriac and the remaining cultivars, and 16.5 between the annual and the other cultivars. The relationship among the celery cultivars disclosed from this study is basically consistent with that observed using total protein and isozyme markers. RAPD technology provides a new alternative for cultivar identification in celery.
INCREASED SHOOT PROLIFERATION OF APPLES CO-CULTIVATED WITH AGROBACTERIUM TUMEFACIENS
Authors: Hammerschlag F.A. , Zimmerman R.H. , Smigocki A.C.
Published: February 2019

`McIntosh' apple shoots were inoculated in vitro with Agrobacterium tumefaciens strain tms328::Tn5 (tms) carrying a functional cytokinin gene. Callus tissue, removed from the infected stems, produced shoots on shoot proliferation medium. After three subcultures, axillary shoot production from a tms-infected putative transformant was eight times that of controls. Subsequent shoot production on three different levels of BA (3, 6 and 10 uM) was significantly greater than from controls on all levels of BA. PCR analysis of putative transformants revealed an expected 503 bp DNA fragment corresponding to the amplified portion of the cytokinin gene. After 6 months of in vitro propagation, proliferation rates of shoots obtained from the original transformants were similar to the controls and the expected PCR fragment of 503 bp could only be detected by Southern analysis. Even though the T-DNA appears to be lost from the apple genome, the data suggest that the tms strain may be useful in co-infection experiments to induce shoot formation, thus avoiding difficult regeneration procedures.
CYTOKININ EFFECTS ON TOMATO SEED QUALITY, FRUIT YIELD, AND RIPENING IN TRANSGENIC PLANTS CARRYING THE ipt GENE
Authors: Smigocki Ann C. , Honeczy Iris J.
Published: February 2019

Lycopersicon esculentum cv. UC82b cotyledons were co-cultivated with A. tumefaciens carrying vectors with modified isopentenyl transferase (ipt) genes. The ipt gene was placed under the control of the RUBISCO promoter in both the sense and antisense orientation. Over 50 transformants were recovered on kanamycin-containing media. Seeds from RO plants were germinated on selective media and R1 plants transformed with the ipt gene identified by PCR and Southern blot hybridization. Phenotypes of the R1 plants, whether transformed with the ipt gene in the sense or antisense orientation, were comparable to the control plants transformed with an inactive cytokinin gene. Fruit weights from both were similar to those from control plants, however, yields were reduced and ripening delayed. Most fruit had no seeds or very few small seeds. Cytokinin levels are being determined in order to correlate them to the observed phenotypes.