Thirteen characters were evaluated over four years in progenies from a diallel cross among the olive (Olea europaea L.) cultivars `Arbequina', `Frantoio', and `Picual' to determine if phenotypic correlations existed between these characters. Yield per tree, ripening date, oil yield components and fatty acid composition were recorded annually once seedlings began to flower and produce fruit. Significant correlations were found between several characters including oil yield components and fatty acids composition. Lower correlation coefficients were obtained between ripening date and oil and oleic acid content. Generally, yield was not correlated with the other characters evaluated. Principal components analysis confirmed the main correlations among characters and showed them to be independent of the parents used.
Lorenzo León, Luis M. Martín, and Luis Rallo
Ravindranath V. Kanamangala, Neils O. Maness, Michael W. Smith, Gerald H. Brusewitz, and Sue Knight
Shelf life is a major problem in the marketing of pecans, particularly at the retail level. A procedure to extend the shelf life of pecans was described. The full-oil and supercritical carbon dioxide extracted (22% and 27% reduced-oil) native pecan kernels packaged in standard air mixture (21% O2, 79% N2), stored for up to 37 weeks at 25 °C and 55% RH, were subjected to hexanal analysis, sensory analysis, and determination of lipid class changes, that occur as the pecans age. Hexanal concentration of reduced-oil pecans was negligible throughout the storage, while full-oil pecans reached excessive levels by 22 weeks. Hexanal analysis was in agreement with the sensory scores. Free fatty acid lipid class was selectively extracted during the partial oil extraction process. Reduction in free fatty acids, and an overall reduction in lipid content on a per kernel basis, decreased the sites for oxidative deterioration and contributed to enhanced shelf-life of pecans. Work was supported by OCAST grant AR4-044 and the Oklahoma Agricultural Experiment Station.
James D. Spiers, Fred T. Davies, Chuanjiu He, Carlos Bogran, Amanda Chau, Kevin M. Heinz, and Terri W. Starman
This research focused on the influence of insecticides on gas exchange, chlorophyll content, vegetative and floral development, and overall plant quality of gerbera (Gerbera jamesonii var. `Festival Salmon'). Insecticides from five chemical classes were applied weekly at 1× and 4× the recommended concentrations. Insecticides used were: abamectin (Avid® 0.15 EC), acephate (Orthene® Turf, Tree & Ornamental Spray 97), bifenthrin (Talstar® Nursery Flowable), clarified hydrophobic extract of neem oil (Triact® 70), and spinosad (Conserve® SC). Phytotoxicity occurred in the form of leaf chlorosis on all acephate treatments, with the greatest damage occurring at the 4× concentration. Photosynthesis and stomatal conductance were significantly reduced in plants treated with neem oil extract. Plants treated with the neem oil extract (1× and 4×) flowered later and had reduced growth [lower shoot dry mass (DM) and total DM]. Plants that received 4× the recommended concentration of neem oil extract had reduced leaf area, thicker leaves (lower specific leaf area), higher leaf chlorophyll content, and reduced flower production, as determined by flower number and flower DM. Plants treated with acephate 4× concentration were the lowest quality plants due to extensive phytotoxicity (leaf burn), which also reduced photosynthesis. The highest quality plants were treated with spinosad and abamectin due to zero phytotoxicity and/or no thrips damage (thrips naturally migrated into the greenhouse). The control plants and plants treated with bifenthrin 1× were not marketable due to thrips damage; however, plant growth characteristics and gas exchange were not statistically different.
Sandra A. Balch, Cynthia B. McKenney, and Dick L. Auld
Oenothera biennis, common evening primrose, produces seeds that have a high oil content containing gamma-linolenic acid (GLA), a fatty acid of medicinal, and dietary importance. These plants are commonly found in sandy or gravelly soils and have the ability to tolerate hot, dry conditions. Plants containing economically important oils such as GLA are potential crops for arid environments with minimal irrigation. Many native species of evening primrose have not yet been evaluated for oil content. In this project, a systematic survey of native Onagraceae species was conducted in the Texas Panhandle and the Texas South Plains. Six species of Oenothera and two species of Calylophus were found. Locations were recorded with a Global Positioning System (GPS) to facilitate relocation and collection. Distribution maps were made for each species. The occurrence of species varied greatly from north to south, with the exception of one species that occurred throughout the area surveyed. Seeds were collected from each species and from various locations within the range of each species. Germination percentages were determined for each species and had a wide variation. Evaluation of the oil content of this native germplasm could possibly lead to development of new commercial sources of GLA.
M. Rawgappa, H.L. Bhardwaj, A.I. Mohamed, M.E. Showhda, and M.E. Kraemer
Thirty-five mint accessions were evaluated during 1993 for agronomic characteristics (leaf texture, color, and pubescence), plant vigor, cold hardiness, insect population interactions, and contents of essential oils, ash, and total protein. These accessions were obtained from National Clonal Germplasm Repository, Corvallis, Oregon during 1992. The rhizomes were planted in the greenhouse on April 2, 1992 and transplanted to the field on May 29, 1992 as a randomized complete block design with three replications. The chemical composition data from whole plants indicated that ash content was dependent upon location from which an accession was collected, ploidy level (diploid vs. polyploid), type of mint (peppermint vs. spearmint), and genetics (hybrid vs. non-hybrid). Diploid accessions had significantly higher essential oil content. The protein content was higher in peppermint types than spearmint types. The hybrid accessions had lower protein content in comparison to non-hybrids.
James D. Spiers, Fred T. Davies Jr., Chuanjiu He, Carlos E. Bográn, Kevin M. Heinz, Terri W. Starman, and Amanda Chau
This study evaluated the influence of insecticides on gas exchange, chlorophyll content, vegetative and floral development, and plant quality of gerbera (Gerbera jamesonii Bolus `Festival Salmon'). Insecticides from five chemical classes were applied weekly at 1× or 4× their respective recommended concentration. The insecticides used were abamectin (Avid), acephate (Orthene), bifenthrin (Talstar), clarified hydrophobic extract of neem oil (Triact), and spinosad (Conserve). Photosynthesis and stomatal conductance were reduced in plants treated with neem oil. Plants treated with neem oil flowered later—and at 4× the recommended label concentration had reduced growth, based on lower vegetative dry mass (DM) and total aboveground DM, reduced leaf area, thicker leaves (lower specific leaf area), higher chlorophyll content (basal leaves), and reduced flower production. Plants treated with acephate at 4× the recommended label concentration were of the lowest quality due to extensive phytotoxicity (leaf chlorosis). Plants treated with 1× or 4× abamectin or spinosad were of the highest quality due to no phytotoxicity and no thrips damage (thrips naturally migrated into the greenhouse). The control plants and plants treated with 1× bifenthrin had reduced quality because of thrips feeding damage; however gas exchange was not negatively affected.
David A. Dierig, Anson E. Thompson, Earl R. Johnson, and Gail H. Dahlquist
Vernonia galamensis is a potential new crop for production of epoxidized oil with many industrial applications. This plant is native to equatorial Africa, and not adapted for culture in temperate zones since it requires a short daylength to initiate flowering and subsequent seed development. One collection of V. galamensis ssp. galamensis var. petitiana, flowered freely and produced seeds during long-day conditions throughout the United States. This variety lacks important plant characters for successful commercialization. The favorable genetic recombination of day-neutral response with more desirable plant growth characteristics, desirable seed oil and fatty acid content from other accessions of V. galamensis has been accomplished in hybrids and segregating populations, and selections are being widely evaluated throughout the U.S..
Haiying Liang, Bing-Qing Hao, Guo-Chen Chen, Hang Ye, and Jinlin Ma
. Depending on the species, cultivar, and environmental conditions, oil content in seeds of traditional camellia varieties can range between 24% and 50% with an average of ≈30% ( Huang et al., 2013 ). Some of the new Camellia oleifera cultivars can reach 53
Diego Barranco, Isabel Trujillo, and Pilar Rallo
The cultivar Oblonga may have originated from a volunteer seedling at an orchard near Corning, Calif., about 1940. Its main virtue is its high degree of resistance to Verticillium dahliae. `Frantoio' is the main variety in Italy and has been planted worldwide because of its high content of top-quality oil. In the present study, we show that both cultivars have the same fifteen morphological and eight agronomical traits and both have amplified the same patterns for 22 RAPD primers and five SSRs. This indicates that `Oblonga' and `Frantoio' are probably the same cultivar.
Laurence Sistrunk, Dan Chapman, and J. Benton Storey
Four cultivars of pecan [Carya illinoinensis (Wangenh.) K. Koch] were selected for the study (`Cheyenne', `Mohawk', `Pawnee', and `Osage'). The influence of total climatic heat units, during nut filling, on nut quality was compared from 14 geographic locations over a 3-year study. Nut quality parameters included nut size by weight, kernel percentage by weight, kernel color by Hunter Color Difference Meter, fatty acid profile by GC, and total oil by NMR. Nuts were harvested at shuck split, dried to 3% moisture, and stored at –20C prior to analysis. Monounsaturated fatty acids (MUFA) and total oil increased, and polyunsaturated fatty acids (PUFA) decreased in `Mohawk' 2 out of 3 years with increased heat units. Fatty acids in `Pawnee' responded the same as in `Mohawk' in 1992, but were variable in 1991. In 1993, `Pawnee' kernel whiteness and total oil decreased with increased heat units. Higher heat units caused the testas of `Cheyenne' to be darker in all 3 years. MUFA of `Cheyenne' increased with increased heat units 1 out of 3 years. The PUFA content of `Cheyenne' decreased with increased heat units in 1993. `Osage' showed a reversal of MUFA and PUFA with increased heat units. High negative correlation between oleic and linoleic acid were obtained for all cultivars.