genetic similarity of the accessions through molecular characterization by target region amplified polymorphism (TRAP) markers ( Hu and Vick, 2003 ). TRAP is a technique that combines the AT- and GC-rich primers of SRAP (sequence-related amplification
Rose Palumbo, Wai-Foong Hong, Guo-Liang Wang, Jinguo Hu, Richard Craig, James Locke, Charles Krause and David Tay
Kristen R. Hladun and Lynn S. Adler
Perimeter trap cropping (PTC) is an effective method of integrated pest management to control herbivores in cucurbit crops ( Boucher and Durgy, 2004 ). Trap crops that are attractive to herbivores are planted around the main crop, concentrating
Tian-Ye Chen, Chang-chi Chu, Thomas J. Henneberry and Kai Umeda
Insects in a commercial poinsettia (Euphorbia pulcherrima) greenhouse were monitored with yellow sticky card (YC) traps and YC equipped with 530-nm lime green light-emitting diodes (LED-YC) traps from 3 June to 25 Nov. 2002. Pest insects were: dark-winged fungus gnat (Bradysia coprophila), sweet potato whitefly (Bemisia tabaci) biotype B (= B. argentifolii), western flower thrips (Frankliniella occidentalis) and leafhopper (Empoasca sp.). Natural enemies were: minute pirate bug (Orius tristicolor), parasitic wasps (Hymenoptera), and rove beetles (Staphylinidae). Over the 24 weeks of the experiment, LED-YC traps captured more dark-winged fungus gnats, sweet potato whiteflies, leafhoppers, and rove beetles compared with YC traps. Capture of western flower thrips, minute pirate bugs, and parasitic wasps were not significantly increased on the YC traps equipped with LEDs. The results indicate that the LED-YC traps attract three major pest insects in poinsettia greenhouses and do not catch more beneficial, minute pirate bugs and parasitic wasps, but may catch significant number of rove beetles. The results suggest that LED-YC traps may be useful to monitor and reduce pest populations in greenhouses.
Rose Palumbo, Wai-Foong Hong, Jinguo Hu, Charles Krause, David Tay and Guo-Liang Wang
The Ornamental Plant Germplasm Center (OPGC) maintains a collection of herbaceous ornamental plants in order to protect future breeders from a loss of genetic diversity. The current Pelargonium collection includes ≈870 accessions. Our preliminary studies showed that TRAP (Target Region Amplified Polymorphism) has promise for analyzing the variation in our collection, and so we have expanded the study to analyze the entire Pelargonium collection. We have used the same primers for this screening of the Pelargonium collection as were used on sunflowers, and TRAP results run on a sequencing gel showed 90–150 bands that segregate the population into groups of similar accessions. In order to facilitate analysis of OPGC's large population, we have converted the method to a high throughput technique that efficiently analyzed the entire population. We used a 96-well DNA extraction kit from Qiagen that produced high quality DNA in spite of the high phenol levels in some Pelargonium species. Also, the use of labeled primers allowed analysis of the gels to be aided by a computer. These results produce a categorization of the collection that, combined with morphology and taxonomy, will form the basis for future studies that will use target genes specific to Pelargonium.
Chang-chi Chu*, Kai Umeda, Tian-Ye Chen, Alvin M. Simmons and Thomas H. Henneberry
Insect traps are vital component of many entomological programs for detection and monitoring of insect populations. We equipped yellow (YC), blue (BC) sticky card (BC) with 530 nm lime green (LED-YC) and 470 nm blue (LED-BC) light-emitting diodes, respectively that increased trap catches of several insect pests. The LED-YC traps caught 1.3, 1.4, 1.8, and 4.8 times more adult greenhouse whitefly Trialeurodes vaporariorum (Westwood), sweetpotato whitefly Bemisia tabaci (Gennadius) biotype B, cotton aphids Gossypium hirsutum (L.), and fungus gnats Bradysia coprophila (Lintner), respectively, compared with standard YC traps. The LED-YC traps did not catch more Eretmocerus spp. than the standard YC traps. Eretmocerus spp. are important B. tabaci parasitoids used in greenhouse biological control programs. For whitefly control in greenhouse the 530 nm lime green LED equipped plastic cup trap designed by Chu et al. (2003) is the better choice than LED-YC trap because it catches few Eretmocerus spp. and Encarsia spp. whitefly parasitoids released for B. tabaci nymph control. The LED-BC traps caught 2.0-2.5 times more adult western flower thrips Franklinella occidentalis (Pergande) compared with the standard BC traps.
Arthur Villordon*, Craig Roussel and Tad Hardy
The Louisiana Dept. of Agriculture and Forestry (LDAF) conducts sweetpotato weevil [SPW, Cylas formicarius (Fabricius)] monitoring in support of the statewide SPW quarantine program. The monitoring activity primarily involves a statewide pheromone-based trapping process that generates trap data for sweetpotato beds and production fields. We conducted GIS analysis of SPW trap data, collected over three years, to assess the potential use of GIS tools in managing and interpreting the data. The LDAF has already generated shapefiles for all beds and fields in each of three years, facilitating GIS analysis. However, trap data was manually collected and statewide data was compiled and stored in spreadsheet files. Trap data was mapped to specific beds and fields in each of three years, generating layers that clearly showed fields and parishes that reported high trap counts. GIS analysis showed potential SPW “hotspots” in each year, indicating that certain beds or fields are more prone to SPW infestation than others. This information can be useful in planning SPW management strategies by growers and other stakeholders. The GIS database also provides the foundation for the development of descriptive and predictive models of SPW occurence in Louisiana. Compiling the SPW trap data into a GIS database allows the data to be distributed over the Internet, facilitating real-time access by stakeholders.
Jinguo Hu, Beiquan Mou and Brady A. Vick
Target region amplified polymorphism (TRAP) markers were used to evaluate genetic variability among 48 accessions of spinach (Spinacia oleracea L.), an economically important leafy vegetable crop in many countries. Thirty-eight accessions collected and preserved by the USDA National Plant Germplasm System (NPGS) and 10 commercial hybrids were used in the current study. For assessing genetic diversity within accessions, DNA samples were prepared from nine to 12 individual seedlings from six germplasm accessions and two hybrids. Relatively high levels of polymorphism was found within accessions based on 61 polymorphic TRAP markers generated with two fixed primers derived from the Arabidopsis-type telomere repeat sequence and two arbitrary primers. For evaluating inter-accession variability, DNA was extracted from a bulk of six to 10 seedlings of each accession. Of the 1092 fragments amplified by 14 primer combinations, 96 (8.8%) were polymorphic and discriminated the 48 accessions from each other. The average pair-wise genetic similarity coefficient (Dice, Nei) was 57.5% with a range from 23.2 to 85.3%. A dendrogram was constructed based on the similarity matrix. It was found that the genetic relationships were not highly correlated with the geographic locations in which the accessions were collected. However, seven commercial hybrids were grouped in three separate clusters, suggesting that the phenotype-based breeding activities have effect on the genetic variability. This study demonstrated that TRAP markers are effective for fingerprinting and evaluating genetic variability of spinach germplasm.
Rose E. Palumbo, Wai-Foong Hong, Jinguo Hu, Charles Krause, James Locke, Richard Craig, David Tay and Guo-Liang Wang
Pelargonium is one of the priority genera collected by the Ornamental Plant Germplasm Center (OPGC). In order to protect future breeders from a loss of genetic diversity, the OPGC collects heirloom cultivars, breeding lines, and wild species. The current Pelargonium collection consists primarily of cultivars originating from P. ×hortorum and P. ×domesticum. Our project was designed to analyze the current collection in order to facilitate the maintenance of a more-diverse core collection. We have expanded our TRAP (Target Region Amplified Polymorphism) analysis from 120 plants with one primer set to include 780 plants with four primer sets. Each primer set consists of a labeled arbitrary primer paired with a gene-specific primer, and two different fluorescent labels were used to allow multiplexed PCR reactions. We scored about 90 markers in each of the first two primer sets and about 60 markers in each of the second two. In comparisons between the phylogeny and the morphology and taxonomy of these plants, we show some matching clusters that may be explained by the breeding history of the plants.
Kai Umeda, C. Fredman, R. Fredman, C.C. Chu and T.J. Henneberry
A whitefly trap recently developed by Chu and Henneberry was tested in a cantaloupe field at the University of Arizona Maricopa Agricultural Center in 1995. The trap was compared with a 3 × 5-inch yellow sticky card trap, a commercial dome trap, and the leaf-turn sampling method. Results showed that the new whitefly trap effectively caught adults in cantaloupes. Numbers of adults increased as whitefly adult population densities increased during the season. Numbers of adults caught by the new whitefly trap were comparable to numbers of adults caught with the commercial dome trap and to a lesser extent the counts of adults determined by leaf-turn sampling method. Results with the new trap were not comparable to adults caught with yellow sticky card traps.
Arthur Villordon, Craig Roussel and Tad Hardy
The Louisiana Department of Agriculture and Forestry (LDAF) conducts sweetpotato weevil (SPW) (Cylas formicarius Fabricius) monitoring as part of the statewide SPW quarantine program. This activity involves a statewide pheromone-based trapping program that monitors sweetpotato beds and production fields. We conducted GIS analysis of SPW trap data, collected over three years, to assess the potential use of publicly available GIS tools in managing and interpreting the data. Trap data was mapped to specific beds and fields in each of three years, generating layers that clearly showed fields and parishes that reported high trap counts. GIS analysis showed potential SPW hotspots in each year, indicating that certain beds or fields are predisposed to SPW infestation than others. This information can be useful in planning SPW management strategies by growers and other stakeholders. The GIS database also provides the foundation for the development of descriptive and predictive models of SPW occurence not only in Louisiana, but in other states where SPW is a potential pest. For example, using presence data for Louisiana and Genetic Algorithm for Rule Set Prediction (GARP), a GIS-based ecological niche modelling tool, we were able to generate predicted distribution using mean minimum temperature for January as the predictor variable. Although additional work is needed to identify other predictor variables and verify the models, the results demonstrate the potential use of GIS-based tools for generating warnings or advisories related to SPW.