gamma rays, ultraviolet irradiation and X-rays have also been used for in situ haploid induction. X-rays have proved to be efficient in melon ( Katoh et al., 1993 ), carnation [ Dianthus caryophyllus ( Sato et al., 2000 )], and pummelo [ Citrus maxima
Kristina Košmrlj, Jana Murovec, and Borut Bohanec
Marisa M. Wall and Shakil A. Khan
Pride LLC, Keaau, HI). The facility uses an electron linear accelerator (5 MeV, model TB-5/15; L-3 Communication Titan Corp., San Diego, CA) and converts the electron beam into x-rays for treatment of produce. Dragon fruit were treated with target
Marisa M. Wall
Diego) and converts the e-beam into x-rays for treatment of produce. Six dosimeters (Opti-chromic detectors, FWT-70-83M; Far West Technology, Goleta, Calif.) were placed inside each box. The dosimeters were read at 600 nm with a FWT-200 reader (Far West
Joongmin Shin, Bruce Harte, Janice Harte, and Kirk Dolan
. Farkas (2006) showed that 1.0 kGy irradiation significantly reduced food spoilage bacteria and extended the sensorial quality of fresh-cut peppers and carrots. Hagenmaier and Baker (1997) found that chlorine sanitization in combination with x-ray
W.J. van der Burg, J.W. Aartse, R.A van Zwol, H. Jalink, and R.J. Bino
Studies based on X-ray photographs were conducted to predict the morphology of tomato (Lycopersicon esculentum Mill.) seedlings at transplanting stage. Currently, seed-lot quality of tomato seeds for growing commercial transplants is determined with grow-out tests in the greenhouse because the standard germination test fails to predict the percentage of normal or usable transplants (UTs). These grow-out tests, however, are difficult to standardize. An X-ray evaluation procedure is presented as an alternative. X-ray images nondestructively provide information on embryo size and morphology and the amount of endosperm and the area of free space. These parameters correlate well with the morphology of 14-day old seedlings. Cotyledon morphology has the highest correlation with the percentage of UTs. A test based on the evaluation of X-ray images, classifying the cotyledon morphology and seed free space, predicts the percentage of UTs more accurately than the currently used germination test. A second method based on an equation that uses the probabilities of all X-ray categories proportionally predicts the percentage of UTs of primed seeds more accurately than the first method. Selecting individual seeds based on X-ray images has the potential to raise the percentage of UTs of seed lots. On the average, the percentage of UTs of control seeds was 22% higher after hand selection based on X-ray evaluation. Primed seeds gave 12% higher results. Hence, X-ray analysis can predict seedling performance and enable the selection of high-quality seeds.
Taryn L. Bauerle and Michela Centinari
(see Fang et al., 2012 for a comprehensive review). High-resolution X-ray CT scanning offers spatiotemporal imaging of root development ( Lontoc-Roy et al., 2006 ; Tracy et al., 2010 ). Primary complexities with this method include root organ (root
Sokrith Sea, Cyril Rakovski, and Anuradha Prakash
(width) × 0.22 m (height). The cartons of pears were then forced-air cooled to 1 to 2 °C and stored for 1 to 3 weeks until shipment in a refrigerated truck to Nutek Corporation (Hayward, CA), a distance of 362 km for X-ray radiation treatment. X-ray
Tao Yuan, Qiuying Wei, Pablo Jourdan, and Yong Kwon Yoo
full, viable seeds with developed vegetative organs (full seed) from empty, nonviable seeds, as demonstrated in Corylopsis coreana Uyeki seeds ( Kim et al., 2017 , 2018 ), could not be evaluated. X-ray imaging may be useful to distinguish full seeds
David Tay, Joseph Tychonievich, and Stephanie Burns
The Association of Official Seed Analysts adopted X-ray technology for testing agricultural and forest tree seeds in 1979. It has not been applied on flower seeds. To date, its use is still lacking, despite the relatively simple and nondestructive nature of the test. One of the reasons for the slow adoption is the lack of a simple X-ray unit that gives instant high resolution digital images. The Faxitron MX-20, a cabinet X-ray unit designed for high detail radiographic imaging of medical specimens, fulfills this need. The high magnification capacity of 1×, 1.5×, 2×, 3×, 4×, and 5×, and the low kilovoltage (kV) provide enhanced image performance with good quality contrast. The exposure time and X-ray tube kV can be selected to produce the best images. Its laser locator eases the positioning of a sample under examination accurately and the 2-× 4-inch field of view digital camera with 10 lp/mm resolution provides the instant high quality on-screen viewing of seed sample images. The most useful application at the Ornamental Plant Germplasm Center is not in seed testing as recommended for agricultural and tree seeds, but as a tool during seed cleaning to see in a matter of seconds whether empty, immature, insect-damaged, and broken seed have been removed. It has proven useful in Achillea, Alstroemeria, Aquilegia, Aruncus, Aster, Baptisia, Begonia, Campanula, Chrysanthemum, Coreopsis, Dianthus, Euphorbia, Geranium, Hemerocallis, Impatiens, Iris, Lilium, Lupin, Lysimachia, Narcissus, Pelargonium, Penstemon, Petunia, Phlox, Platycodon, Ranunculus, Rudbeckia, Salvia, Silene, Stokesia, Tagetes, Talinum, Verbena, Veronica, and Viola.
Susan M. Stieve and David Tay
Storage of quality herbaceous ornamental seeds is a primary concern of the Ornamental Plant Germplasm Center, a USDA National Plant Germplasm System genebank. In Autumn 2005, 30 accessions, including 10 genera of herbaceous ornamentals, were evaluated for initial seed weight and viability using four replications of 50 seeds except for Begonia, which consisted of two replications of 500 seeds due to extremely small seed size. Seed lots were then recleaned using an Oregon Seed Blower; Begonia were cleaned using the rolling paper method where good, round seeds roll off vibrating paper held at an angle and shrunken seed do not. Heavy and light fractions of all seeds were saved, 50-seed weight calculated, and viability tested. Seed cleaning was assisted by Faxitron X-ray technology to identify the quantity of seeds with embryos in each treatment. Seed cleaning statistically increased the weight for 19 accessions including Actea, Antirrhinum, Oenothera, Penstemon, Ranunculus, Rudbeckia, and Talinum, where the heaviest seed were in the heavy fraction of recleaned seed. Seed weight for some Begonia and Tagetes accessions was statistically increased, while weight of no Petunia accessions was increased. Viability was calculated as the percentage of normal and dormant seeds. Seed cleaning statistically increased the viability of 10 accessions including Actea, Oenothera, Petunia, Ranunculus, and Talinum; seed lot viability was statistically increased for some accessions of Antirrhinum, Penstemon, Rudbeckia; no accessions of Begonia or Tagetes had improved viability. Results suggest that recleaning seed lots to improve seed weight and viability may be effective, but differences between genera as well as species within genera exist.