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Joseph Postman, Gayle Volk, and Herb Aldwinckle

Gene discovery and marker development using DNA-based tools require plant populations with well-documented phenotypes. If dissimilar phenotype evaluation methods or data scoring techniques are used with different crops, or at different laboratories for the same crops, then data mining for genetic marker correlations is challenging. For example, apples and pears may share many of the same disease resistance genes. Fire blight resistance evaluations for apples often use a scale of 1 to 5 and pear evaluations use a scale of 1 to 9. In some reports, a low number means low susceptibility and in other reports, a low number means low resistance. Other disease evaluations rate resistance as greater than or less than a well-documented standard cultivar. Environment, pathogen isolate, and whether disease ratings are the result of natural infection or artificial inoculation also have a strong impact on disease resistance ratings. Before a wider set of disease resistance phenotype data can be correlated with genetic data, rating scales must be standardized and the evaluation environment must be taken into account. Standardizing the recording of disease resistance data in plant phenotype databases will improve the ability to correlate these data with genomic data.

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John L. Norelli and Herb S. Aldwinckle

Regeneration from apple (Malus × domestica Borkh.) M.26 leaf tissue was completely inhibited by (μg·ml-1) 1 geneticin, 5 kanamycin, 10 to 25 paromomycin, and 100 neomycin. nptII-transgenic M.26 had an increased tolerance to all four of the antibiotics tested, with inhibition of regeneration occurring at (μg·ml-l) 2.5 geneticin, 100 kanamycin, 375 paromomycin, and 375 neomycin. Paromomycin (100 to 250 μg·ml-l) and neomycin (250 μg·ml-1) significantly increased the amount of regeneration from nptII-transgenic M.26 apple leaf tissue. p35SGUS-INT, a plasmid with a chimeric b -glucuronidase gene containing a plant intron, was useful for studying the early events of apple transformation by eliminating GUS expression from Agrobacterium tumefaciens. It was used to determine that the optimal aminoglycoside concentrations for the selection of nptII-transgenic M.26 cells were (μg·ml-1) 2.5 to 16 kanamycin, 63 to 100 neomycin, and 25 to 63 paromomycin. Geneticin was unsuitable as a selective agent.

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Winthrop B. Phippen and James E. Simon

102 POSTER SESSION 4D (Abstr. 211–217) Growth & Development–Vegetables/Herbs

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B.H. Alkire and J.E. Simon

An experimental steam distillation unit has been designed, built, and tested for the extraction of essential oils from peppermint and spearmint. The unit, using a 130-gal (510-liter) distillation tank, is intermediate in size between laboratory-scale extractors and commercial-sized distilleries, yet provides oil in sufficient quantity for industrial evaluation. The entire apparatus-a diesel-fuel-fired boiler, extraction vessel, condenser, and oil collector-is trailer-mounted, making it transportable to commercial farms or research stations. Percentage yields of oil per dry weight from the unit were slightly less than from laboratory hydrodistillations, but oil quality and terpene composition were similar.

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James Luby, Philip Forsline, Herb Aldwinckle, Vincent Bus, and Martin Geibel

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Gennaro Fazio, Herb S. Aldwinckle, Terence L. Robinson, and James Cummins

The Geneva® Apple Rootstock Breeding program initiated in 1968 by Cummins and Aldwinckle of Cornell University and continued as a joint breeding program with the USDA-ARS since 1998, has released a new dwarf apple rootstock named Geneva® 41 or G.41. G.41 (a progeny from a 1975 cross of `Malling 27' × `Robusta 5') is a selection that has been tested at the N.Y. State Agricultural Experiment Station, in commercial orchards in the United States, and at research stations across the United States, Canada, and France. G.41 is a fully dwarfing rootstock with vigor similar to M.9 T337, but with less vigor than M.9 Pajam2. It is highly resistant to fire blight and Phytophthora with no tree death from these diseases in field trials or inoculated experiments. G.41 has also shown tolerance to replant disease. Its precocity and productivity have been exceptional, equaling M.9 in all trials and surpassing M.9 in some trials. It also confers excellent fruit size and induces wide crotch angles in the scion. It appears to be very winter hardy and showed no damage following the test winter of 1994 in New York. Propagation by layering in the stool bed G.41 is not consistent and may require higher layering planting densities or tissue culture mother plants to improve its rooting. G.41 also produces some side shoots in the stool bed. The nursery liners of G.41 produce a smaller tree than G.16 liners, but similar to M.9, which is very acceptable. Unlike G.16, G.41 is not sensitive to latent viruses. G.41 has similar graft union strength to M.9 and requires a trellis or individual tree stake when planted in the orchard. Suggested orchards planting densities with this rootstock are 2,000-4,000 trees/ha. This rootstock has been released for propagation and commercial sale by licensed nurseries.

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Hany M. El Naggar, Paul E. Read, and Susan L. Cuppett

Poster Session 39—Herbs, Spices, and Medicinals 2 20 July 2005, 1:15–2:00 p.m. Poster Hall–Ballroom E/F

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Fredy R. Romero, Kathleen Delate, and David J. Hannapel

Poster Session 39—Herbs, Spices, and Medicinals 2 20 July 2005, 1:15–2:00 p.m. Poster Hall–Ballroom E/F

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Bennett J. Sondeno and Karen L. Panter

Oral Session 19—Herbs, Spices, and Medicinal Plants Moderator: Karen L. Panter 19 July 2005, 4:00–6:00 p.m. Room 101

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Rao Mentreddy, Cedric Sims, Usha Devagiri, and Ernst Cebert

Oral Session 19—Herbs, Spices, and Medicinal Plants Moderator: Karen L. Panter 19 July 2005, 4:00–6:00 p.m. Room 101