bluuebunny/crossref_metadata_2025 huggingface dataset:
(34) Maintaining the Analytical and Microbial Quality of Fresh-cut Apple Slices using Hot Water Pretreatment and a Low pH Dip Treatment
Authors: Saftner Robert , Abbott Judith , Bhagwat Arvind
Published: February 2019

A calcium ascorbate processing formulation is commercially used to prevent browning on fresh-cut apple slices but has little to no antimicrobial activity. Intact apples were surface-sanitized with chlorine water at 20 °C or water at 60 °C, processed into fresh-cut slices, and the slices dipped in a calcium ascorbate formulation or a solution of isoascorbic acid, calcium, and N-acetylcysteine at pH 2.0. The commercial and experimental dip treatments similarly maintained cut surface color, Kramer firmness, and aromatic volatile concentrations during 3 weeks of storage at 5 °C in air. Freshly prepared experimental dip treatment reduced the native bacterial population of the apple slices prepared from sanitized apples better than the calcium ascorbate treatment. With repeated use, the experimental dip solution became adulterated with apple tissue and juice and rapidly lost its antibacterial activity. Concomitantly the pH of the dip solution increased to 2.6 or higher. The lost antibacterial activity could be restored in highly contaminated experimental dip solutions by back titrating to pH 2.0. The experimental dip treatment also reduced the overall yeast and mold population, but specifically enhanced growth of Penicilliumexpansum on slices prepared from chlorine-sanitized apples. A hot water pretreatment of intact apples at 60 °C for 3 min prior to fresh-cut processing essentially eliminated P. expansum contamination on the slices. The results indicate that the experimental dip treatment is a promising alternative to calcium ascorbate treatment for analytical and microbial quality retention of fresh-cut apple slices during storage, especially when the apple slices are processed from hot water-treated apples.
(35) The Influence of 1-MCP on Firmness, Soluble Sugar Levels, Chlorogenic Acid, and Total Phenolic Compounds in Ripening Banana Fruit
Authors: Stanley Daniel A. , Huber Donald J.
Published: February 2019

In previous studies, 1-methylcyclopropene (1-MCP) was shown to significantly suppress peel degreening and appearance of senescent spotting of banana fruit (Stanley and Huber, 2004). In the present study, the effect of the ethylene antagonist on banana pulp soluble sugar levels and on peel soluble and total phenolics was measured. One hundred and sixty hands (10 boxes) of banana fruit (Musaacuminata cv. Cavendish) were treated with ethylene (300 μL·L-1, 24 h, 15 °C, 90% RH) at a commercial ripening facility in Bradenton, Fla., and transported by truck (15 °C) to the University of Florida. Fruit were sorted and placed in 174-L ripening chambers, where 80 hands received 500 nL·L-1 1-MCP for two 12-h periods at 18 °C, while the other 80 hands (controls) were maintained in identical containers without 1-MCP for equal time periods at 18 °C. Mean whole fruit firmness in both treatment groups was 140 N and decreased to 15 N (controls) and 30 N (1-MCP) by day 12. Soluble sugars in the pulp of control fruit achieved levels between 160–180 mg·g-1 fresh weight by day 8, while 1-MCP treated fruit required about 12 days to achieve similar soluble sugar levels. Total phenolic compounds present in peel tissue of control and 1-MCP treated fruit required 10 and 14 days, respectively, to achieve levels of about 4000 μg·g-1 fresh weight. Chlorogenic acid levels, a subset of total peel phenolic compounds, peaked above 500 μg·g-1 by day 10 in control fruit and by day 12 in 1-MCP treated fruit. Maintenance of fruit firmness along with the achievement of acceptable sugar levels of 1-MCP treated fruit demonstrate possible benefits of suppression of ethylene action for retail and processing markets for banana fruit.
(36) The Influence of 1-Methylcyclopropene (1-MCP) on `Athena' Cantaloupe Fruit Harvested at the Pre-ripe, Half-slip, and Full-slip Development Stages
Authors: Jeong Jiwon , Huber Donald
Published: February 2019

The present study was performed to characterize the physiological responses of cantaloupe [Cucumismelo (L.) var. reticulates`Athena'] fruit harvested at preripe (1/4 slip), half-slip, and full-slip stages of development and treated with 1-methylcyclopropene (1-MCP) prior to storage at 13 or 15 °C. Cantaloupe fruit (1/4 to full-slip stage) were treated with 1-MCP (0.01 and 1 μL·L-1) for 18 hours at 20 °C and then stored at 15 °C (pre-ripe fruit) or 13 °C (half- and full-slip fruit). The firmness of pre-ripe `Athena' fruit was significantly retained in response to 1 μL·L-1 1-MCP, but did not differ greatly from control fruit in response to 0.01 μL·L-1 1-MCP. Control fruit reached an edible condition (≈70 N) after 6 days of storage at 15 °C and persisted until day 12 (50 N), whereas 1 μL·L-1 1-MCP-treated fruit reached an edible stage after 17 days and persisted through 21 days (over 60 N). Fruit treated with 1-MCP exhibited slightly (0.01 μL·L-1) or dramatically (1 μL·L-1) lower electrolyte leakage throughout storage. 1-MCP (1 μL·L-1) significantly suppressed ethylene production and respiratory rates of pre-ripe cantaloupe during storage at 15 °C. Firmness retention was also highly significant for cantaloupe harvested and treated with 1-MCP (1 μL·L-1) at the half-slip and full-slip stages of development. 1-MCP treatment had a significant effect at reducing decay incidence and the occurrence of depressed or sunken regions of the fruit surface.
(37) Metabolism of Apple Peel Constituents during Ripening is Differently Regulated by Ethylene
Authors: Mattheis James , Rudell David
Published: February 2019

Metabolism of peel constituents was assessed during ripening of `Delicious' and `Golden Delicious' apples. The ethylene action inhibitor 1-methylcyclopropene (1-MCP) and/or controlled atmosphere storage (CA) were used to limit ethylene activity during and after storage at 1 °C. `Delicious' apples not exposed to 1-MCP developed a brownish discoloration (not superficial scald) during the initial 2 months of storage in air. LC/MS analyses of peel components indicated 1-MCP and/or CA inhibited the degradation of compounds responsible for red peel color (i.e., idaein) as well as other flavonoids. Ethylene regulation of metabolism of other phenolic and related constituents including (-)epicatechin and chlorogenic acid appears to be compound specific. The (-)epicatechin content is not impacted by 1-MCP or CA, while chlorogenic acid accumulation is reduced in fruit exposed to 1-MCP and/or stored in CA. β-carotene and lutein content in peel of `Delicious' fruit stored in air was lower compared with untreated controls. Chlorophyll degradation was enhanced in air-stored fruit previously exposed to 1-MCP; however, this result was not observed in 1-MCP exposed fruit from CA. Results for `Golden Delicious' apples also indicated that exposure to 1-MCP and CA, as well as storage duration, impacts metabolism of peel constituents. Chlorophyll degradation was delayed in fruit previously exposed to 1-MCP and then stored in CA. Impacts of 1-MCP and storage environment on concentrations of other `Golden Delicious' peel constituents increased with storage duration. The results indicate metabolism of apple fruit peel constituents during fruit ripening is differentially regulated by ethylene.
(162) Edible Fungal Growth and Fruiting on Composted Containerized Inedible Crop Biomass
Authors: Nyochembeng Leopold M. , Beyl Caula A. , Pacumbaba Rodulfo P.
Published: February 2019

Current goals for space exploration are predicated upon long-term manned space flights and colonization of planetary habitats. Long periods in space without payloads of necessary items from Earth require the development of a self-sustaining ecosystem that will allow astronauts to grow their own food and efficiently recycle the waste products. Crops suggested for growth in space include wheat, rice, carrots, soybean, mushrooms, etc. Optimal and rapid biodegradation of lignin and other cellulosic material of crop residues by candidate edible white rot fungal strains is paramount in the use of these organisms to achieve effective biomass recycling in an advanced life support system (ALS). The incorporation of organic N into the substrate and pairing crop residues may enhance growth and fruiting of the edible fungi, thus increasing the rate of biodegradation of the substrates and biomass recycling. We investigated the mycelial growth of two strains of Pleurotusostreatus (`Grey Dover' and `Blue Dolphin') on processed single vegetative residues of soybean, cowpea, tomato, sweetpotato, or their 1:1 combination with wheat or rice straw. Growth and fruiting of the two strains including another strain (`Pohu') on rice straw mixed with solid thermophilic aerobic reactor (STAR) effluent for degradation and recycling were also studied. Mycelial growth and fruiting in `Grey Dover' and `Blue Dolphin' were significantly repressed on sweetpotato and basil; however, growth of the two strains was improved when sweetpotato and basil substrates were paired with rice or wheat straw. Fruiting was prolific in paired combinations of soybean with wheat or rice straw. High concentration of STAR residue enhanced mycelial growth; however, a relatively lower concentration was required for abundant fruiting.
(229) `Lost Hills' Pistachio—A New and Improved Cultivar
Authors: Parfitt Dan E. , Kallsen Craig E. , Maranto Joe
Published: February 2019

`Lost Hills' is a new female pistachio cultivar that is being released as a potential replacement for `Kerman', the industry standard female cultivar. `Lost Hills' produced substantially higher percentages of split, edible nuts than `Kerman' in 2003 when split percentages for `Kerman' were very poor due to reduced winter chilling, a condition that is likely to be more frequent in the future. Nut size for `Lost Hills' is larger than for `Kerman'. Harvest date is 2–4 weeks earlier than `Kerman', which will permit growers to extend their harvest period and better utilize their harvesting equipment and personnel. Earlier harvest may reduce disease in the northern production areas of California by permitting an earlier harvest before fall rains, as well as reducing navel orangeworm infestations. The cultivar requires less chilling than `Kerman', which improves uniformity of foliation, bloom, nut set, nut fill, and uniformity of nut maturity at harvest in years with insufficient chilling for `Kerman'. This cultivar could increase grower profits by more than 20% above that received for `Kerman'.
(230) Genetic Differences in Sweet Cherry Fruit Size Are Determined by Cell Number and Not Cell Size
Authors: Olmstead James W. , Iezzoni Amy F. , Whiting Matthew D.
Published: February 2019

Although maximizing fruit size is critical for profitable sweet cherry (Prunusavium L.) production, little is known about the cellular differences among and between cultivars that contribute to fruit size differences. A wide range of fruit size exists among sweet cherries, and, due to cultural and environmental differences, significant variation exists among genetically identical fruit from the same cultivar. To determine the relative contributions of flesh cell number and cell size to final fruit size in sweet cherry, equatorial sections of three cultivars with a wide range in final average fruit size [`New York 54' (NY54; 1.4 g fresh weight, 11.8 mm diameter), `Emperor Francis' (EF; 6.1 g, 21.0 mm), and `Selah' (12.8 g, 25.5 mm)] were created from mature fruit. Cells intersecting a transverse line were counted and average cell length was calculated. The average cell numbers were significantly different (P ≤ 0.05) between `NY54', `EF', and `Selah' (26.7, 47.4, and 83.2, respectively), indicating that flesh cell number is the major contributor to differences in fruit size between cultivars. Flesh cell numbers of `NY54', `EF', and `Selah' were similar at bloom and increased rapidly for a short duration after fertilization, suggesting a key developmental period for fruit size differences. To determine the contribution of cell number differences to variation in fruit size within a cultivar, fruit from `Bing' and `Regina' trees exhibiting a range of size due to cultural and environmental differences were measured. In both cases, average cell number was not significantly different (P = 0.9, P = 0.3, respectively), while average cell size was (P ≤ 0.05), further indicating fruit flesh cell number is a genetically controlled trait.
(231) Correlation of Cluster Number and Tendril Density in Grapevines
Authors: Cousins Peter
Published: February 2019

The grapevine shoot has a zone in which leaf-opposed clusters are found at the nodes. Beyond the cluster zone, leaf-opposed tendrils are borne at the nodes in a patterned distribution. Cluster number is a primary yield component and selection programs for increasing yield in grapevine frequently consider cluster number. However, selection for increased cluster number requires direct observation, which is only possible once the vine matures. Clusters and tendrils are developmentally related, so it may be that tendril density (tendrils per node) reflects cluster number. In contrast to cluster number, tendril density can be observed on plants of all ages. The hypothesis that tendril density is related to cluster number was tested here. Cluster numbers and tendril density were assessed on 10 primary shoots each of 180 grapevine (Vitis) accessions. The accessions analyzed are cultivars and wild species collections held in the United States National Plant Germplasm System. The correlation coefficient of the number of clusters and tendril density was calculated using the means of 10 observations per accession. Tendril density was determined by calculating the mean number of tendrils per node in the nodes beyond the cluster zone. Cluster number and tendril density were positively correlated; the correlation coefficient was 0.35. This implies that vines with more tendrils per node also tend to have more clusters. The positive correlation of cluster number and tendril density has implications for grapevine improvement, pointing to the possibility of indirect selection for higher cluster number through selection for higher tendril density. Correlation between juvenile tendril density and mature cluster number is yet to be tested.
(297) Continuous Fogging using a Nozzle with an Upward Air Stream Contributes to Steady Air Temperature during Greenhouse Cooling
Authors: Toida Hiromi , Kozai Toyoki , Handarto  , Ohyama Katsumi
Published: February 2019

Fogging systems are still not widely used for greenhouse cooling, primarily due to their low fog: evaporation ratio, resulting in a low cooling efficiency and a high risk of pathogen expansion caused by excess wetness of plant foliage. The fogging is operated intermittently because of these problems. Consequently, the air temperature and relative humidity fluctuates inside the greenhouse. If nozzles with a high fog: evaporation ratio are employed, the fogging can be operated continuously. By continuous fogging, steady air temperature and relative humidity can be achieved inside the greenhouse. In our previous study under indoor conditions, a high fog: evaporation ratio was achieved by installing two small fans close to a conventional upright nozzle in order to obtain an upward air stream. The objective of this study was to draw a comparison between the environmental conditions inside a greenhouse with the continuous fogging with small fans and that with the conventional intermittent fogging without fans. Reduced fluctuation of the air temperature and relative humidity inside the greenhouse were observed in the case of continuous fogging as compared with that observed in the case of intermittent fogging. The air temperature inside the greenhouse during cooling was lower than that before cooling in both methods. In the case of continuous fogging, the adjustment of the amount of fogged water will provide the desired environmental conditions inside the greenhouse.
(303) Challenges of Organic Hydroponic Production of Strawberries (Fragaria ×ananassa)
Authors: Jewell Brandon , Kubota Chieri
Published: February 2019

Feasible protocols for organic hydroponic production of strawberry are necessary and this study compares the yield and fruit quality of organic and conventional inorganic hydroponic production. Some issues identified with organic hydroponic strawberry production are: 1) dominant ammonium nitrogen form; 2) solution alkalinity; and 3) dissolved oxygen level of nutrient solution. Eighty bare-rooted `Diamante' plantlets were planted in coconut fiber pots with a mixture of coconut coir (30%) and perlite (70%) and grown in a modified nutrient film technique system inside a polycarbonate greenhouse. The organic nutrient solution contains mostly ammonium nitrogen and little nitrate nitrogen. To enhance colonization and activities of nitrifying bacteria, coconut fiber mats were placed in the organic nutrient solution reservoir. A similar system was also introduced for stock solution pre-conditioning where nitrification and pH stabilization were achieved before application to the strawberry plantlets. The organic nutrient solution prior to pre-conditioning had only 1.53 mg·L-1 nitrate nitrogen, although the nitrate nitrogen level increased to 63.2 mg·L-1 after pre-conditioning. The organic nutrient solution pH was 4.5 initially, 8.5 after 24 hours of pre-conditioning, and finally, shifted to and stabilized at 5.7–5.9 after 3 days. Dissolved oxygen level is critical for both nitrifying bacteria activities and plantlet root growth; therefore, oxygen enrichment was achieved by constantly aerating the nutrient solution in the reservoir, which raised the oxygen level from 2.5 to 7.4 mg·L-1. Comparisons of yield and quality of strawberry fruits between organic and inorganic nutrient solutions will be presented and further improvements of hydroponic systems will be discussed.
(64) Effect of Plug Flats on Posttransplant Growth and Prevention of Stunting
Authors: Donnell Aliya , Dole John
Published: February 2019

Plug production is an integral part of today's floriculture industry. However, if seedlings are held in plug flats for too long, they may not return to a normal growth rate after transplanting. Stunting may render plants unsuitable for sale. Common bedding plant and cut flower species were grown in 288-plug flats to determine how long plugs could be held in the flats and still regain a normal growth rate and desirable growth form after transplanting. Species surveyed included: Antirrhinum, Begonia, Brassica, Callistephus, Celosia, Consolida, Dianthus, Eustoma, Gazania, Helianthus, Impatiens, Lycopersicon, Matthiola, Tagetes, and Viola. Ten randomly selected plugs were transplanted to 15- or 17-cm pots every 1 or 2 weeks for 10 weeks, when root balls were sufficiently developed to hold together after removal from the flat. Overall plant height was recorded for all species every 1 or 2 weeks. Plant diameter was recorded every 2 weeks for Begonia, Celosia, Eustoma, Helianthus, Impatiens, Lycopersicon, and Tagetes. A plug was considered to be stunted if it died after transplanting or did not resume a normal growth rate. Species that exhibited stunting included Brassica, Callistephus, Celosia, Consolida, Dianthus, and Tagetes. For example, Consolida seedlings held in the plug flat for 7 weeks after optimal transplanting time were six times smaller than those that were transplanted at the optimal time. Several factors were investigated to determine how they affected the degree of stunting, including: light quality, root obstruction, nitrogen enrichment prior to transplanting, gibberellic acid addition prior to transplanting, teasing of the root ball prior to transplanting, and length of drainage column.
(69) Effects of Photoselective Shadecloths on Growth and Flowering of Potted Chrysanthemum
Authors: Kobayashi Kent D.
Published: February 2019

Controlling plant height is an important practice in the ornamental plant industry. Though commonly used, growth regulators are expensive, and there are concerns about environmental consequences and safety of workers. Alternative ways of controlling growth may be advantageous. The objective of this study was to determine the effects of photoselective shadecloths on the growth and flowering of `Arezzo' chrysanthemum. One-month-old potted `Arezzo' chrysanthemum plants were grown in a saranhouse in chambers built with PVC (polyvinyl chloride) pipe covered with 30% shadecloths—red, blue, gray, and black (control). The blue shadecloth was more effective in reducing plant height, with no differences among the other shadecloths. Plant canopy dimensions—greatest canopy width and average canopy width—did not show any differences among the shadecloths. The red shadecloth was more effective in hastening flowering, followed by the blue shadecloth. This was evident by flowering first occurring with the red shadecloth and initially the greatest number of buds showing color. Additionally, the red shadecloth had the highest proportion of the number of flowers to the combined number of flowers and buds showing color. Specifically, the total number of flowers was similar to the total number of buds showing color. In contrast with the other shadecloths, there was a greater number of buds showing color than the number of flowers. The most buds showing color occurred with the gray shadecloth. The three shadecloths resulted in a greater number of the combined buds showing color and flowers than the black shadecloth. In conclusion, photoselective shadecloths may provide an alternative to controlling plant height and altering the flowering pattern of potted chrysanthemums.
(65) Evaluation of Curcuma as Potted Plant and Cut Flower
Authors: Roh Mark , Lawson Roger , Lee Jong Suk , Suh Jeung Keun , Criley Richard A. , Apavatjrut Pimchai
Published: February 2019

Sixteen accessions of Curcuma germplasm and several selected accessions of Curcuma were evaluated for use as potted plants or as cut flowers. Curcuma alismatifolia Gagnep. and C. thorelii Gagnep. `Chiang Mai Snow' met standards for cut flower and pot plant use, respectively. Furthermore, C. parviflora Will. `White Angel' proved to be a good selection for potted plant production. Optimum storage temperatures of rhizomes were studied in relation to greenhouse forcing and carbohydrate changes. It is recommended to store rhizomes at 25 to 30 °C after harvest for 2 to 3 months to break dormancy. Plants of C. parviflora `White Angel' flowered in 50 to 89 days and C. `CMU Pride' flowered in 104 days after potting, and were acceptable as potted plants. Plants of C. alismatifolia flowered 96 to 133 days after potting with floral stem length suitable for use as a cut flower. A high level of boron or manganese may cause the burn at the margin of the leaves (marginal leaf burn) observed on old leaves of `CMU Pride' at flowering. The level of ethanol-soluble fructose, glucose, and sucrose in elongated rhizomes with emerged short shoots of Curcuma was higher than the level in rhizomes and increased as storage temperatures increased. Accelerated leaf emergence may be associated with the increase in the glucose and fructose content. Based on the similar morphological characters between C. thorelli `Chiang Mai Snow' and C. parviflora `White Angel', identification of Curcuma accessions is required in future studies.
(68) Ceratostigma plumbaginoides Is an Intermediate-day Plant
Authors: Kim Ki Sun , Cameron Arthur C. , Runkle Erik S.
Published: February 2019

We performed experiments to determine the photoperiodic response of Ceratostigma plumbaginoides Bunge., or leadwort, which is a low-growing hardy herbaceous perennial native to China with deep gentian-blue flowers. Tip cuttings were rooted in 72-cell trays and grown under a 24-hour photoperiod for 2 weeks and then transplanted into 11.4-cm pots and grown for one more week. Plants were then placed under different primary photoperiods (10, 16, or 24 hours) for 4, 6, or 8 weeks, then transferred to secondary photoperiods (10, 14, 16, or 24 hours) at a constant 20 °C. Pots were also placed under continuous 10, 14, 16, or 24 hours. Nearly all plants flowered under all treatments except under continuous 10- or 24-hour photoperiods, in which no plants flowered. Plants grown under 14 hours flowered earliest (50 days), followed by plants under the 16-hour primary treatment. The 10-hour primary treatment delayed flowering for as long as its duration, whereas the 16-hour primary photoperiod initiated rapid flowering, regardless of duration and subsequent secondary photoperiod. Flowering was also delayed when the primary photoperiod was 24 hours. Collectively, these responses indicate that Ceratostigma is an intermediate-day plant.
(70) Hydroponic Sunflower Production as Influenced by Cultivar, Nitrogen Fertilization, and Root-knot Nematode Infestation
Authors: Chen Yan , Merhaut Donald , Becker J. Ole
Published: February 2019

Nitrogen (N) fertilization is critical for successful production of cut flowers in a hydroponic system. In this study, two sunflower cultivars: single-stand `Mezzulah' and multi-stand `Golden Cheer' were grown under two N fertilization rates: 50 mg·L-1 and 100 mg·L-1 in a recirculating hydroponic system. At the same time, `Mezzulah' sunflowers were biologically stressed by exposing each plant to 2000 second-stage juveniles of the plant parasitic nematode Meloidogyne incognita, race 1. The experiment was conducted in May and repeated in Sept. 2004, and plant growth and flower quality between control and nematode-infested plants were compared at the two N rates. The two cultivars responded differently to fertilization treatments. With increasing N rate, the dry weight of `Mezzulah' increased, while that of `Golden Cheer' decreased. Flower size and harvest time were significantly different between the two cultivars. However, N had no effect on flower quality and harvest time. Flower quality rating suggests that quality cut stems can be obtained with 50 mg·L-1 N nutrient solution. Nematode egg count suggests that plants in the nematode treatment were successfully infested with Meloidogyne incognita, however, no significant root galling was observed, and plant growth and flower quality were not affected by nematode infestation.
(74) Effect of Temperature on Axillary Bud Formation and Polyamine Contents of Nonbranching Chrysanthemum
Authors: Huh Yeun Joo , Choi Seoung Youl , Shin Hak Ki , Pak Chun Ho
Published: February 2019

Nonbranching chrysanthemums [Dendranthema × grandiflorum (Ramat.) Kitamura] are preferred because they require less labor in disbudding. High temperature is responsible for this phenotype of not having axillary buds or poor lateral shoot development. This study attempted to find out the effect of temperature and identify the involvement of endogenous polyamine contents in axillary bud formation of nonbranching chrysanthemum cv. Iwanohakusen. Plants were treated at 22, 26, 30, 34, and 38 °C for 9 hours midday for 2 months. Polyamine content [putrescine (Put), spermidine (Spd), spermine (Spm)] was analyzed 1 month after treatment and axillary buds were counted when the flowers opened. Results revealed that viable axillary buds decreased remarkably at 30 and 34°C. It was also found out that not only low temperature, but also the excessively high temperature of 38 °C induced axillary bud formation. Exposure to 38 °C increased the Put contents and resulted in high Put/(Spd + Spm) ratio as 22 °C, 26 °C. Temperature of 30, 34 °C lowered Put/(Spd + Spm) ratio. Results further showed that not polyamine contents, but polyamine ratio (Put/Spd + Spm) or transformation of Put to Spd and Spm may be involved in the axillary bud formation in nonbranching chrysanthemum.
(77) Toleranceto Rhizoctonia solani and Garden Performance of Wax Begonia Cultivars
Authors: Bogran Carlos E. , Pemberton H. Brent , Isakeit Thomas , Roberson William R.
Published: February 2019

A strain of Rhizoctonia solani was isolated from wax begonia (Begonia Semperflorens-Cultorum hybrids) plants in garden evaluation trial plots. This strain was then used to test for disease tolerance in a controlled environment experiment. Inoculated plants of 12 cultivars were evaluated for disease development and the area under the disease progress curve was calculated. No plants were disease free, but `Stara White', `Stara Pink', and three colors from the Party series exhibited greater disease tolerance than `Ambassador Coral', `Ambassador Deep Rose', and two experimental varieties. `Stara White', `Party Pink Bronze Leaf', and `Party White Bronze Leaf' were more tolerant than `Cocktail Vodka', an industry standard. When the same cultivars were grown in field garden evaluation plots, `Cocktail Vodka', four colors from the Stara series, and three colors from the Party series exhibited superior garden performance and flowering ratings to `Ambassador Coral' and an experimental `Rose' cultivar. For most cultivars, garden performance was correlated to disease tolerance. However, `Cocktail Vodka' exhibited good garden performance despite having a high level of disease in the inoculation experiment, indicating that other factors may be involved in determining garden performance.
(263) Temperature Effects on Meristem Identity Genes Controlling the Reproductive Development of Cauliflower (Brassica oleracea var. botrytis) and Broccoli (Brassica oleracea var. italica)
Authors: Duclos Denise V. , Björkman Thomas N.
Published: February 2019

Brassica oleracea species differ in the developmental stage of their reproductive meristems at harvest. The stage that characterizes each variety depends on its genetic makeup, environment and the interaction between them. We tested a model of arrest in B. oleracea to determine functional redundancy among the paralogous genes CAL, AP1a, AP1c, FULa, FULb, FULc, and FULd; and to resolve the immediate effect of temperature on gene expression in meristems whose developmental fate is temperature regulated. By varying temperature during reproductive development, three stages of arrest were obtained: inflorescence meristem (cauliflower), floral meristem (intermediate) and floral bud (broccoli), the latter initiated by low temperature. Gene expression was measured by quantitative real time PCR (qRT-PCR). The LFY/TFL1 ratio increased as the reproductive development advanced, mainly due to decreased TFL1 expression; influenced by a dramatic increase in AP1c toward floral bud formation. The expression patterns of the FUL paralogs indicate different roles in reproductive development. FULa was more abundant in the floral primordia, while FULb, FULc, and FULd were associated with earlier arrest at the inflorescence meristem stage. The high expression of FULc and FULd at all stages of arrest differs from their homolog in Arabidopsis. High temperature reduced AP1 and LFY expression but the meristem did not revert from reproductive to vegetative. Floral bud formation in plants recessive for AP1a and CAL reaffirm that functional redundancy among some of these genes can complement the mutations. Varying temperature alone, at a fixed developmental stage, caused little variation in the expression of genes studied, causing small significant differences in TFL1 and AP1c.
(268) Nonspecific Fusarium Wilt Resistance in Watermelon Using Copper Inducible IPT Gene
Authors: Goktepe Fahrettin , Hughes Harrison
Published: February 2019

`Crimson Sweet' watermelon was transformed with a copper inducible ipt gene. Clonally propagated transformed and non-transformed plants were sprayed with three different concentrations (0, 50, 100 mm) of CuSO4 at the 2–3 leaf stage twice in a 24-hour period prior to their inoculation with fusarium wilt organisms. Plants were inoculated via root dip with two different isolates of Fusariumoxysporum sp. niveum Race 2. The pathogenic strains of Fusariumoxysporum sp. niveum Race 2, Fl 99-1, and Calg 15-19, were cultured on PDA solid medium and then transferred to a sterile flask filled with 50 mL of potato dextrose broth (PDB) liquid medium. These flasks were placed on a shaker at 100 rpm for 4–5 days before the inoculation date and the final concentration of 106 spores/mL was adjusted for inoculation. Roots of the experimental units were gently washed and were then infected by dipping them in to the beaker containing the isolates for 1 min. Inoculated plants were transferred to planting trays and maintained under growth chamber conditions. Plants then were watered as needed. Fusarium wilt symptoms initially appeared approximately 7–10 days after the infection. The Cu-ipt transformants exhibited a clear and significant resistance over non-transformed plants. The severity of disease development was relatively higher in the control Cu-ipt and non-transformed plants when compared to the plants treated with CuSO4. The control Cu-ipt plants were comparatively healthier than the control non-transformed plants. Infected plants were removed from soil 2 weeks after inoculation, washed and the stems were cut vertically for rating of browning of the vascular system.
(353) University of California Water Quality Program for Floriculture and Nursery Growers in Ventura and Los Angeles Counties
Authors: Newman Julie , Gilbert Kristine , Faber Ben , Merhaut Donald , Wu Laosheng , Gan Jay , Evans Richard
Published: February 2019

Nursery growers must implement “Best Management Practices” (BMPs) to mitigate runoff and leaching of pollutants. However, there is little data on the effectiveness of BMPs, and further research is needed. Growers require training to minimize runoff and capital to comply with evolving regulations. We collected irrigation efficiency data at 26 nursery sites using catch cans. Uniformity value was calculated as: DU = 100 × (Average of the “Low Quarter”/Average of All Measurements). Results showed that one-third of the nurseries had irrigation uniformities below 67%, and only one nursery exceeded 82%. Continuous flow monitoring at 10-minute intervals was conducted at three nursery sites to determine daily and monthly variation. One hundred samples of the runoff were taken four times at each nursery and analyzed for nitrate, chloride, and sulfate. We developed a 29-page checklist of BMPs to reduce runoff, which we used to survey 53 growers in Ventura County. After completing the survey, 20 growers applied for funds from a 1.2 million dollar cost-share program that we initiated. This program provides funds to implement improved technologies to reduce runoff and/or conserve water; funds were awarded to 18 nurseries. We are collecting monitoring data from each cooperating nursery implementing improvements. These data measure the number of BMPs used by growers, provide a current “snapshot” of the industry, and document the effectiveness of future BMP implementation. We offer on-farm consulting, and conducted eight water quality/irrigation educational programs—four in Spanish. We elevated grower awareness concerning regulations and options for reducing runoff, and the data will be useful in evaluating future improvements.
(354) A Novel Automated System for Irrigation and Simulating Drought Stress in Potted Plants
Authors: Nemali Krishna S. , van Iersel Marc W.
Published: February 2019

We have developed a completely automated irrigation system that measures and maintains substrate volumetric water content (θ) at a target level for any length of time. Advantages of this system include complete automation of irrigation and simulation of precise levels of drought stress for potted plants. This system uses ECH2O moisture sensors interfaced with a CR10X datalogger and solenoid valves connected to the datalogger by a SDM CD16 AC/DC controller. The datalogger measures the θ of the substrate hourly. When the θ of the substrate drops below the set point, the datalogger opens the solenoid valves, which results in irrigation. Substrate θ is maintained at a constant level as the datalogger is programmed to increase θ by 2% to 3% during each irrigation. When the system was validated for its accuracy, we determined that the θ measured in the substrate within the range of 0.15 to 0.35 m3·m-3 was close (2% to 3%) to the θ determined by the conventional volumetric analysis. The daily average θ maintained in the substrate was slightly higher (within 3%) than the target level. Using this system, we were able to maintain four distinct levels of substrate θ for a prolonged period (40 days), regardless of differences in plant size and environmental conditions. Significant increases in number of irrigations, total water-use, and transpiration rate of impatiens, salvia, vinca, and petunia were noticed with increasing target θ of the substrate. For all species, highest and lowest water-use efficiency (WUE) were seen at 0.09 and 0.32 m3·m-3, respectively, while WUE was not different between 0.15 and 0.22 m3·m-3.
(356) Adaptation of Makkink Model to Obtain Potential Evapotranspiration under Sonoran Desert Conditions
Authors: Robles-Contreras Fabián , Grijalva-Contreras Raul Leonel , Valenzuela-Ruiz Manuel de Jesus , Macias-Duarte Rubén
Published: February 2019

Water is a very limited resource in the Sonoran Desert region of Caborca, Sonora, Mexico. For an efficient use of irrigation water, a method of calculating water requirements of the crops is needed. Potential evapotranspiration (Eto) value obtained with the Penman-Monteith model from a regional weather station was not dependable, since some parameters, such as sensible heat flux in the soil, are estimated from a fixed rate with net radiation (Rn), also an estimated value. The weather station did not have a sensor for heat flux in its network. Studies in northwestern Mexico have indicated that it is feasible to adapt the use of the Makkink model, because a single measurement of solar radiation and temperature would be required. We compared the daily Makkink Eto against the Class A pan method (control) Eto during 75 days and found a value of 0.81 mm/day less with the Makkink model. To fit the Makkink model to regional conditions, we ran the Makkink model varying the value of C constant (from 0.5 to 0.95), and found that a value of C = 0.87 substituted for C = 0.65 (original value) has an daily average difference of 0.09 mm/day less with respect to the control. This could be because there are few clouds in the region, and a greater proportion of global radiation arrives at the surface from the earth or the crops in form of net radiation.
(248) New Four Genes Related to Seed Characteristics, Flower Appearance, and Red Color
Authors: Kim Zhoo-Hyeon
Published: February 2019

New four traits not yet reported were founded. One mutant plant was from a population of 81-1251-D-20M treated with EMS (ethylmethane sulfonate), which had tubular petals. This tubular petal plant had normal pollens in anthers, but could almost not produce its seeds without artificial pollination. It was controlled by one single recessive gene. One new spontaneous dwarf mutant line, R3-10, which bore seedcoatless-like seeds with short pappus, was crossed with normal breeding lines GL5 and 87-25M-2M. From F2 and F3 results, it was found that the two traits (seedcoatless-like and short pappus) were governed by each one single recessive gene. A stem lettuce type cultivar, `Baimach', seemed to be almost green, but was really tinged red, which was extremely suppressed in red color expression. Its tinged red color could not be seen, except on only very limited base parts of the stem and dorsal petal. In two F2 population experiments of the crosses of `Baimach' with `Oakleaf' and 98-43-3, it was found that the suppression of red color expression in `Baimach' was caused by a single recessive gene. It looked different from that of gene “v” (vanishing) by Lindqvist, because the red color of plants with “v” gene of Lindqvist were typically tinged and could be identified easily at a young plant stage, but not that of `Baimach'. I designated these new four genes as Tu-tu (Tu = normal, tu = tubular petal), Pp-pp (Pp = normal, pp = short pappus), Scl-scl (Scl = normal, scl = seedcoatless-like), and In-in (In = normal, in = inhibiting red color expression extremely).
(251)`Evergreen' and F415: Two New Spinach Varieties for the Mid-South
Authors: Morelock Teddy E. , Correll J. C. , Dainello Frank J. , Motes D. R.
Published: February 2019

Spinach, Spinacia oleracea, is a highly nutritious vegetable that is increasing in popularity more rapidly than any other salad crop. In the eastern United States spinach production is severely impacted by white rust, Albugo occidentalis. For many years, the University of Arkansas has bred spinach to cope with this endemic problem. While fungicides can provide a degree of control, the combination of genetic resistance and fungicides is the most effective method to insure production stability. `Evergreen' and F415 are the latest developments of this breeding program. `Evergreen', widely tested as Ark 88-212, is a slow growing, dark green, semi-savoy spinach that exhibits a good level of white rust resistance. It is not long-standing and should not be used for spring production in Arkansas and Oklahoma. It has been widely tested in Arkansas and Texas. F415, widely tested as Ark 91-415, is an upright, dark green, flat leaf spinach that has a good level of white rust resistance. It is is well suited to the Arkansas, Oklahoma and Texas production area and, because of its better color and more upright growth habit, it should replace Ark F380.
(252) Correlation of Pungency, Thiosulfinates, Antiplatelet Activity, and Total Soluble Solids in Two Garlic Families
Authors: Cavagnaro Pablo , Senalik Douglas , Galmarini Claudio , Simon Philipp
Published: February 2019

Allium plants possess organosulfur compounds and carbohydrates that provide unique flavor and health-enhancing properties. In previous studies of onion F3 families, significant phenotypic and genetic correlations have been reported between pungency, in vitro antiplatelet activity (IVAA), and soluble solids content (SSC); although in other studies SSC and pungency have not always been correlated. In this study we analyzed SSC, pungency, garlic-induced in vitro antiplatelet activity and the content of three predominant thiosulfinates in bulbs from two garlic families obtained from unrelated self-pollinated plants. A strong positive correlation was observed between pungency and IVAA for both sample sets, indicating that it will be difficult to develop garlic populations with low pungency and high IVAA. Allicin was the most abundant thiosulfinate and its content was positively correlated with pungency and IVAA (r= 0.70 and 0.74, respectively). The thiosulfinates AllS(O)SPropenyl and AllS(O)SMe were also positively correlated with pungency and IVAA. When compared with IVAA, AllS(O)SMe had higher r values than AllS(O)SPropenyl (0.88 and 0.50, respectively). These differences could reflect differential platelet anti-aggregatory properties of different thiosulfinates. SSC was not correlated with IVAA, pungency, or thiosulfinates content, suggesting that soluble solids in garlic can be independently selected.
(253) TAM `Dulcito' and `Tropic Bell'—Two New Sweet Peppers with Enhanced Beneficial Phytochemical Levels
Authors: Crosby Kevin M. , Leskovar Daniel I. , Yoo Kil Sun
Published: February 2019

At the Vegetable and Fruit Improvement Center, plant breeding has produced pepper lines with enhanced beneficial phytochemical levels. TAM `Dulcito' is a new jalapeño cultivar with no detectable levels of capsaicin, but increased levels of lutein. In greenhouse cultivation, it contained 122 ppm of this important human health-related compound, which aids in prevention of macular degeneration. This is a significant improvement over popular cultivars, such as `Grande', which contained 25 ppm or less. In addition to improved lutein levels, `Dulcito' also possesses resistance to three important potyviruses: TEV, PepMoV, and PVY. In field trials at Weslaco, Texas, `Dulcito' outyielded both TAM `Mild Jalapeño 2', and `Mitla'. This new cultivar produces a concentrated set of large, thick-fleshed fruit with few cuticular cracks. Because of its lack of pungency, it should be useful for the processing industry. TAM `Tropic Bell' is a medium-sized, blocky bell with enhanced levels of both ascorbic acid and lutein compared to other cultivars. Grown under greenhouse conditions, it contained 100 ppm lutein compared to 6 ppm in `Jupiter'. It also contained 660 ppm ascorbic acid at the green stage, compared to less than 100 ppm for three commercial bell cultivars tested. `Tropic Bell' produced yields equal to both `Valiant' and `Summer Sweet' commercial hybrids at Weslaco. Fruit of `Tropic Bell' were slightly smaller than the hybrid cultivars. TAM `Tropic Bell' possesses resistance to the same three potyviruses as `Dulcito' and demonstrated excellent tolerance to Phytophthora capsici in a controlled inoculation. These two new cultivars will be useful for production in locations with high potyvirus pressure or as specialty market items for health-conscious consumers.
(274) Inter- and Intra-specific Variation in Yield and Quality Traits of Chile Pepper Breeding Lines
Authors: Chinthakuntla Reddy R. , Matta Frank , Mentreddy Rao S. , Reddy Umesh , Nimmakayala Padmavathi , Peterson Daniel , Vadhwa Om Prakash
Published: February 2019

Chilepepper (Capsicum spp.) is the third most important vegetable crop in the United States. The market value of chile peppers for spices and condiments exceeds $650 million per year. With a growing Hispanic population across the United States, the demand for high yielding, good quality cayenne pepper continues to increase. In order to fulfill this niche market, a study has been initiated to develop pepper varieties that combine high yield potential with superior agronomic traits, including insect and disease resistance, and fruit characteristics, using molecular marker assisted breeding/selection. In preliminary trials, several F1 generations were created through inter- and intra-specific crosses among 220 germplasm lines belonging to six Capsicumsp. in the greenhouse. Selected F1 progeny, parent lines, and selected accessions were planted in single-row field plots the following summer. The crossing success was higher within species than between. The genotypic variation was significant for all parameters examined. The average percent germination (81.1) of F1 progeny was 32% and 45% higher than that of the parent lines and selected accessions, respectively. The F1 progeny were shorter in height; more vigorous in growth, flowered early, and with fewer, but heavier, fruits per plant out-yielded the parent lines and accessions by 50% and 120%, respectively. The study showed a marked heterosis in F1 progeny compared to the parent lines and accessions. Microsatellite genotyping to estimate genetic diversity and validation of markers that are linked to various traits is in progress and will be discussed in the presentation.
(277) Behavior of Glomus intraradices in Agave Roots Transformed with Agrobacterium rhizogenes
Authors: Rodríguez Guillermo , Aguilar-Espinosa Sergio , Balch Eugenio Perez-Molphe , Flores-Bello María del Rocío , Farias-Larios Javier , López-Aguirre José Gerardo
Published: February 2019

The present work is the first report in vitro on root induction of Agave salmiana Otto, using Agrobacterium rhizogenes. Several concentrations of bacteria and acetosyringone were used, and different inoculation sites were tested, such as leaves, shaft, and root. Incubation time in darkness was 6 days. The transformed adventitious roots appeared 25 days after inoculation. The best treatment was when the shaft was inoculated with: 1 × 108 bacteria/mL and 100 μm acetosyringone; in this treatment, induction of transformed roots was 57.5% in the inoculated sites. The activity and presence of the foreign genes in the transformed roots of A. salmianawere verified as follows: 1) histochemical staining for GUS activity was determined in 80% of the tested root; and 2) molecular analysis via PCR was made to verify the presence of nptII gene and rol B gene (both were present in 60% of the tested root). This is the first report of the arbuscular mycorrhizal colonization on wild roots and transformed roots of Agavewith Glomus intraradicesSchenck and Smith. The result of the monoxenic culture was as follows: mother spore germinated 5 days; the colonization of the transformed roots was 70%. Then we proceeded to the recovery of daughter spores, in which we obtained an average 300 daughter spores per petri dish, 6 months after inoculation.