Ethylene is essential for the senescence process in many fruit and flowers. In the last two steps in the biosynthesis of ethylene in plants ACC synthase converts S-adenosyl methionine to 1-aminocyclopropane-1-carboxylic acid(ACC). ACC oxidase (ACO) then degrades ACC to ethylene. Inhibitors of ethylene synthesis, such as amino-oxyacetic acid, and of the response to ethylene, such as silver thiosulphate, delay or prevent senescence. By expression of an antisense version of ACO RNA, we have generated two varieties of transgenic carnation which produce flowers with an extended vase life. These were produced using the cultivars Red Sim and White Sim. Flowers from these plants produce very little ethylene and normally fail to display the inrolling phenotype typical of senescence in this species. At the time after harvest when inrolling would normally lake place (5 days), the antisense ACO flowers produce only barely detectable levels of endogenous ACO mRNA or ACS (ACC Synthase) mRNA. Exposure to exogenous ethylene(100ppm) induces inrolling and production of ACS and ACO mRNA species. Such carnations will be valuable both as a commercial product and as a tool for further exploring the role of ethylene in carnation flower senescence and leaf wound response.
Keith W. Savin, Stanley C. Baudinette, Michael W. Graham, Ellen L-J. White, Michael Z. Michael, Ann Bayly, Chin-Yi Lu, Stephen F. Chandler, and Edwina C. Cornish
Geno A. Picchioni, Steven A. Weinbaum, and Patrick H. Brown
85 ORAL SESSION 23 (Abstr. 171–177) Temperate Fruit Crops: Nutrition
Kyung-Ku Shim, Yoo-Mi Ha, and Jae-Ho Ha
This cultivar originated from a grafting mutant in grafted plants of a selected 100-year-old seedling of Hibiscus syriacus L. for 5 years. In 1999, the plant is named H. syriacus `Andong'. Hibiscus syriacus `Andong' is a deciduous, erect-growing, multiple-stemmed, dwarf type that, in 7 years, has grown 120 cm high and 65 cm wide, with dense branching to the base. It has more than 200 flowers in a 7-year-old tree. The alternate, leathery, waxy, dark green leaves are 5.3 cm long, 3.8 cm wide. But it is 0.48 mm thick and 34.42 mg/cm2 of fresh weight and then is thickier and heavier than that of other cultivars. Therefore, the plant is rarely damaged by aphids and is reliably hardy to -20 °C. The flowers are white with a prominent dark red eye spot that radiates along the veins to midpetal, 5-7 cm in diameter, and blooms profusely from July to October. Total flowering time of `Andong' was 36 h in both 1998 and 1999. It sets very little fruit. AIt does not only germinate by pollen, but also by seeds. This cultivar can be readily propagated by softwood (on 24 July with 7000 ppm IBA in the mist) or hardwood cutting (1000 ppm IBA) and by grafting on seedling H. syriacus understock.
Andrew G. Reynolds, Margaret Cliff, Douglas A. Wardle, and Marjorie King
Eighty-five cultivars, selections and clones of winegrapes (Vitis) from European breeding and selection programs were evaluated between 1993–95 in a randomized completeblock experiment. These included selections from Alzey, Freiburg, Geilweilerhof, Geisenheim, Weinsberg, and Würzburg (Germany); Hungary; and the former USSR. Vines were grown under an organic management regime that included sodium silicate sprays for powdery mildew (Uncinula necator) control and oil + detergent for insect control but with little to no nitrogen or other nutritional inputs. The Weinsberg cultivars Heroldrebe and Helfensteiner showed promise viticulturally and sensorially as alternatives to `Pinot noir'. Cultivars from Geisenheim (`Gm 7117-10' and `Gm 7117-26') and Würzburg (`Cantaro' and `Fontanara') appeared promising as `Riesling' alternatives; many displayed similar sensory characteristics to `Riesling', along with reasonable viticultural performance. Cultivars selected at Alzey (`Faberrebe'), Freiburg (`Nobling'), and Weinsberg (`Holder') displayed sensory characteristics superior to the standard cultivar Müller-Thurgau, with very intense muscat, pear, fig, and spicy aromas and flavors. Several muscat-flavored Hungarian white wine cultivars appeared to be superior viticulturally and sensorially to the standard `Csabagyongye'; these included `Kozma Palne Muscotaly', `Zefir', and `Zengo'. Miscellaneous red wine cultivars that showed promise included Geilweilerhof cultivar Regent, and Hungarian selections Kozma 55 and Kozma 525. Vine yields decreased substantially in the 3-year evaluation period, primarily due to lack of nitrogen. Many of these cultivars appeared to be highly adaptable to viticultural regions where cold winters and low heat units during fruit maturation presently restrict cultivar choices.
Jose X. Chaparro, Patrick J. Conner, and Thomas G. Beckman
al., 1990 ) suggests that a 400 chill unit variety like ‘GulfAtlas’ would fruit well at a location where the coldest month averaged 12 to 14 °C ( Sharpe et al., 1990 ), i.e., in a band starting a little south of Attapulgus to around the latitude of
C.R. Unrath, J.D. Obermiller, A. Green, and S.J. McArtney
aminoethoxyvinlyglycine (AVG; Retain; Valent BioSciences, Libertyville, IL) to delay drop. Holding fruit on the tree beyond the normal harvest date may also increase crop value due to an increase in fruit size (yield) and improvement in red color development. Byers and
Soon-Il Kwon, Jeong-Hee Kim, Sun-Ae Kim, Young-Soon Kwon, and Jinwook Lee
storability and marketability. In addition, fruit are very attractive and flavorful. ‘RubyS’ cultivar is higher in fruit weight and yield than ‘Alpsotome’. Fruit shape and overall peel color coverage of ‘RubyS’ are ‘conic’ and ‘red’, respectively. Moreover
Brian Makeredza, Helen Marais, Michael Schmeisser, Elmi Lötze, and Willem J. Steyn
less severe the sunburn browning and bleaching on an affected fruit is likely to appear, irrespective of the underlying damage to the peel. Although red color development may mask underlying sunburn symptoms, some sources argue that the accumulation of
Hua Gao, Zheng-yang Zhao, Yu-miao Lu, Yi-zhen Wan, Lei-cun Wang, Jing-jun Yuan, and Peter M. Hirst
globose, and skin color is variable from red stripes to full red over a greenish yellow background. Fruit ripen 2 weeks earlier than ‘Gala’. Leaves and fruits have higher resistance to apple ring moth ( Lithocolletis ringoniella Mats.), apple leaf spot
A. Maaike Wubs, Ep Heuvelink, Leo F.M. Marcelis, Gerhard H. Buck-Sorlin, and Jan Vos
/730-nm Skye sensor, respectively, at three positions per plot. Weather was cloudy with little natural radiation and assimilation light was switched on. Expt. III: Manipulating light intensity and red:far-red ratio by application of neutral shading paper