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M. A. L. Smith, S. L. Knight and M. J. Bass

A whole plant microculture (WPMC) screening system facilitated rapid, quantitative appraisal of salt stress effects on `Micro-Tom' miniature dwarf tomato. Axillary bud explants were micropropagated on a hormone-free control medium (conductivity = 3.3 dS m-1), gradually introduced to treatments with increasing NaCl or Na2SO4 concentrations via biweekly subculture to fresh media (7,6, 12.8, or 18 dS m-1), and monitored over a subsequent 5 week culture period. Non-intrusive video image analysis techniques were adapted to quantify morphometric (shoot growth rate, area, and length; root length and area) and photometric (ruler and tissue quality) plant responses. Shoot growth was only slightly inhibited at 7.6 and 12.8 dS m-1, but was severely stunted and distorted on high salt (18 dS m-1) media. Root growth inhibition (significantly shorter and thinner primary rants) was first evident at 12.8 dS m-1 after 3 weeks of treatment. At 18 dS m-1, conspicuous retardation of root growth relative to controls could be gauged after only one week. Shoot tip chlorosis was observed in the lowest salt-supplemented treatment after three to four weeks of culture, but overall shoot yellowing at the two highest conductivities was marked after only a few days. Chlorosis symptoms were not uniform within treatments. Cell osmotic concentration showed a linear increase with increasing medium salinity. The WPMC system expedited time course observations of stress symptom development, paralleled stress response trends observed in solution culture tests, and provided an excellent vehicle to investigate plant adaptation to saline conditions.

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Nirmal K. Hedau, Shri Dhar, Vinay Mahajan, Hari S. Gupta, Karambir S. Hooda and Vedprakash

al., 2004 ). Because of the dwarf plant habit, short duration, and quality pods, ‘Contender’ has been widely cultivated by the Indian farmers of northwestern Himalayan states (Uttarakhand, Himachal Pradesh, Jammu, and Kashmir). Hence, in this article

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Shahab Hanif-Khan, Robert C. Bullock, Peter J. Stoffella, Charles A. Powell, Jeffrey K. Brecht, Heather J. McAuslane and Raymond K. Yokomi

Silverleaf whitefly (SLW) (Bemisia argentifolii Bellows and Perring) feeding was associated with development of tomato irregular ripening (TIR) symptoms. `Micro-Tom', `Florida Basket', `Florida Lanai', and `Florida Petite' dwarf cherry tomatoes (Lycopersicon esculentum Mill.) were infested with adult SLW to observe oviposition preference, plant tolerance, and TIR symptom development in two experiments. There was no oviposition preference among the cultivars in either of the trials. TIR fruit symptoms were expressed as longitudinal red streaks with yellow, green, pink, or red blotches externally and white tissue internally. External TIR symptoms at the pink stage of ripening ranged from 32% (`Micro-Tom') to 82% (`Florida Basket') in Expt. 1 and 44% (`Micro-Tom') to 93% (`Florida Petite') in Expt. 2. In Expt. 1, external TIR symptoms disappeared from 18% (`Florida Lanai') to 37% (`Micro-Tom') and, in Expt. 2, 16% (`Micro-Tom') to 39% (`Florida Basket') of the fruit during ripening. SLW-infested plants exhibited 82% (`Florida Lanai') to 99% (`Florida Basket') and 76% (`Micro-Tom') to 90% (`Florida Petite') of fruit with internal white tissue regardless of external symptoms in Expts. 1 and 2, respectively. Tomatoes with severe TIR symptoms rarely ripened to full red. Postharvest characteristics of ripening SLW-infested and control fruit were evaluated (Expts. 3 and 4). Generally, the SLW-infested fruit were lighter in color than the control fruit. The control fruit developed normal red color while the SLW-infested fruit developed a blotchy, streaky color that was overall more of an orange-red. SLW-infested fruit were firmer than the control fruit in both experiments. Ethylene production was higher in SLW-infested fruit. While the total soluble solids contents were not significantly different between the treatments, the SLW-infested fruit were more acidic than the control fruit. Each cultivar was susceptible to oviposition by SLW and induction of TIR symptoms. However, TIR symptom expression differed among the cultivars. Despite higher ethylene levels, the ripening process in the SLW-infested fruit appeared slower or may have been inhibited by factors induced by the SLW compared with the control fruit, which ripened normally.

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Mikeal L. Roose, Frank Suozhan Cheng and Claire T. Federici

The `Flying Dragon' cultivar of Poncirus trifoliata L. Raf. is a strongly dwarfing rootstock for Citrus cultivars, reducing canopy volume of 9 year-old `Valencia' orange trees to 1/3 that of trees on standard rootstocks Open-pollinated seed of `Flying Dragon' was screened with isozyme markers to distinguish zygotic from nucellar (apomictic) seedlings. All zygotics had genotypes consistent with an origin by self-pollination. Zygotic seedlings were budded with `Valencia' orange scion and planted in the field. Of 46 progeny evaluated as rootstocks, 35 produced small trees similar to those on nucellar `Flying Dragon' and 11 produced large trees. This ratio is consistent with the 3:1 segregation expected for a single dominant gene. The dwarfing gene was closely linked, or pleiotropic with a gene causing curved thorns and stems. Several RAPD markers close to the dwarfing gene were identified with bulked segregant analysis. `Flying Dragon' apparently originated as a mutation because it had au identical genotype to non-dwarfing strains of trifoliate orange at all 38 isozyme and RFLP markers tested

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Darunee Thawornchareon, Unaroj Boonprakob and Kriengsak Thaipong

‘KU Garnet No.1’ is a maroon-leaved dwarf guava suitable as an ornamental plant that can be grown either directly in the landscape or for container production. In addition, ‘KU Garnet No.1’ produces year-round sweet, edible fruits containing high

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Robert M. Frymire and Janet C. Henderson

Uniform liners of pyracantha (Pyracantha coccinea Roem `Lalandei'), photinia (Photinia × fraseri Dress) and dwarf Burford holly (Ilex cornuta Lindl. and Paxt. `Burfordii Nana') were potted into 3.8 liter containers in a pine bark:sand medium. Ten weeks later, plants received uniconazole treatments as a media drench or foliar spray. The uniconazole drench rates were 0, 0.5, 1.0, and 3.0 mg ai per container for all three plant species. The foliar application rates were 0, 50, 100 and 150 ppm for pyracantha, 0, 25, 50 and 100 ppm for photinia, and 0, 10, 25, and 50 ppm for dwarf Burford belly. Plant heights and widths were recorded at 3 week intervals, and leaf chlorophyll content was determined by calorimeter at the same time as height and weight measurements. At harvest, leaf counts, leaf areas, and shoot, leaf and root dry weights were determined. Initial results indicate that both foliar and media drench treatments of uniconazole reduced growth of pyracantha and photinia at all rates. Only the two highest rates decreased growth of dwarf Burford holly when applied as either a media drench or a foliar spray.

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Zhanao Deng, Brent K. Harbaugh and Natalia A. Peres

encouraged to prolong their life. Availability The caladium cultivars UF-331 and UF-340 will be sold and marketed under the trade name Angel Wing Dwarf Tricolor and Angel Wing Dwarf White. A plant patent application will be submitted to the U

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Yong-Koo Kim

As Korea is located 33-38° latitude in north hemisphere, her capacity availing deciduous fruit growing is enough in allowing successful production of persimmon, oriental pear, jujube and dwarf apple. There are two kind of persimmons, sweet and astringent, and the majority of persimmon production is the sweet one owing to the higher price and consumer preferences. Astringent persimmons are dried after peeling and served as a traditional, popular fruit punch in Korea. The most popular oriental pear cultivar in Korea is Shinko (`Niitaka'), occupying 38% of the total pear growing area. This cultivar is extending its popularity in world trade with 4,361 tons of fruits exported to Taiwan, Singapore, USA, Netherlands, etc. The future of oriental pear is quite promising along with the increasing acknowledgement of its crispness among westerners as well as oriental people living abroad. Production status of jujube and dwarf apple, mostly `Fuji' and `Tsugaru' on M.26 rootstock, will be presented with describing merits and problems of their production.

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Wesley Autio*, LaMar Anderson, Bruce Barritt, Robert Crass-weller, David Ferree, George Greene, Scott Johnson, Joseph Masabni, Michael Parker and Gregory Reighard

`Fuji' apple trees [Malus ×sylvestris (L.) Mill. Var domestica (Borkh.)] on nine dwarfing rootstocks (CG.4013, CG.5179, G.16N, G.16T, M.9 NAKBT337, M.26 EMLA, Supporter 1, Supporter 2, and Supporter 3) were planted at 10 locations (CA, KY MO NC OH 2 in PA SC UT and WA) under the direction of the NC-140 Multistate Research Project. After four growing seasons (through 2002), largest trees were on CG.4013. Smallest trees were on M.9 NAKBT337, Supporter 1, Supporter 2, and Supporter 3. Trees on CG.5179, G.16 N, G.16T, and M.26 EMLA were intermediate. Cumulative root suckering was greatest from trees on CG.4013 and similar from the other rootstocks. CG.4013, CG.5179, and G.16T resulted in the greatest yields per tree in 2002, and M.26 EMLA, M.9 NAKBT337, Supporter 2, and Supporter 1 resulted in the lowest. Cumulatively, CG.4013 resulted in the greatest yields per tree, and M.26 EMLA resulted in the lowest. Rootstock did not affect yield efficiency in 2002, but cumulatively, Supporter 1, Supporter 2, and Supporter 3 resulted in the most efficient trees, and M.26 EMLA the least. Fruit weight in 2002 or on average was not affected by rootstock. Limited data will be presented on CG.3041, CG.5202, and CG.5935, which are planted only at some locations. Data for the fifth season (2003) will be presented.

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Wesley Autio*, John Cline, Robert Crassweller, Charles Embree, Elena Garcia, Emily Hoover, Kevin Kosola, Ronald Perry and Terence Robinson

`McIntosh' apple trees [Malus ×sylvestris (L.) Mill. Var domestica (Borkh.)] on 10 dwarfing rootstocks (CG.3041, CG.4013, CG.5179, CG.5202, G.16N, G.16T, M.9 NAKBT337, Supporter 1, Supporter 2, and Supporter 3) were planted at 10 locations (MA, MI MN NS 2 in NY ON PA VT and WI) under the direction of the NC-140 Multistate Research Project. After four growing seasons (through 2002), trees on CG.5202 and CG.4013 were significantly larger than those on all other rootstocks. Smallest trees were on M.9 NAKBT337. Trees on other rootstocks were intermediate. Rootstock did not influence cumulative root suckering. Yield per tree in 2002 was greatest from trees on CG.4013 and lowest from trees on M.9 NAKBT337; however, cumulatively, trees on M.9 NAKBT337 and CG.4013 yielded the most. Yield efficiency in 2002 was not affected by rootstock. Cumulatively, rootstock had very little effect, but trees on CG.5202 were the least efficient. In 2002, M.9 NAKBT337, CG.3041, and Supporter 2 resulted in the largest fruit, and CG.5179 resulted in the smallest. On average, M.9 NAKBT337 resulted in the largest fruit, and G.16T resulted in the smallest. Limited data will be presented on CG.5935 and M.26 EMLA, which are planted only at some locations. Data for the fifth season (2003) will be presented.