Two cultivars of tulip (Tulipa gesneriana L.) were used to check the effect of trehalose-feeding on longevity of vase life. `Oxford' plants were grown from bulbs, and trehalose-fed cut flowers were compared with the intact plants grown in pots. `Pink Diamond' flowers were obtained commercially as cut flowers from the market, and trehalose-feeding was examined by using only flower parts. In both cultivars of plants, it was confirmed that trehalose-feeding enhanced longevity of the vase life significantly at room temperature. Additionally, mechanisms of prolonging the vase life with trehalose-fed flowers were studied by comparing the water status in the zone of elongation of tulip tepals when their growth rates were modified with different treatments. In the elongating region of tulip tepals, cell elongation rates were linearly correlated to sizes of the growth-induced water potential regardless of treatments. It was found that trehalose-feeding reduced the hydraulic conductance, resulting in a decrease in cell elongation rates. Also, trehalose helped to maintain turgor of tepal cells for longer periods. Furthermore, trehalose enhanced pigmentation in tepals, and thus, trehalose is believed to have had a role in altering the metabolism in elongating cells and in reducing hydraulic conductivity in membranes.
Hiroshi Wada, Mari Iwaya-Inoue, Mitsuru Akita, and Hiroshi Nonami
Melanie F. Haber, Eric Young, and M. Faust
Polyethylene glycol (PEG-4000)-induced water stress (—0.5 to —7.5 bars) reduced shoot and root growth, water use, and stem 45Ca in seedlings of peach (Prunus persica (L.) Batsch). Sucrose feeding through a leaf did not affect stem 45Ca with or without osmotic stress. 45Calcium uptake per milligram water used was not different at different solution osmotic potentials. A split-root study, with half the root system receiving 45Ca and/or PEG, showed that if 45Ca was supplied only to the water-stressed root half, 45Ca uptake into stems was low regardless of whether the other root half was stressed or not. Results indicate that reduced stem Ca during water stress is probably not a direct result of decreased root energy needed for active uptake or reduced translocation out of the root. Calcium absorption appeared to be related to the amount of unsuberized root surface available for Ca uptake.
C. I. Lee and W. P. Hackett
The root-regenera ting potential (RRP) of one-year-old Pistacia chinensis seedlings at different growth stages was determined by recording the number of newly initiated roots during the period of 4 weeks after bare-root transplanting into a bottom misting chamber. RRP of intact pistacias was greatest when leaves were fully expanded and the terminal bud was forming (stage III) and lowest when seedlings were in a dormant condition (stages V and VI). However, seedlings disbudded before transplanting and also root cuttings showed two peaks in RRP; one at spring bud break (stage I) and the other at stage III. Removal of buds resulted in decreased RRP at stage I, but had little effect when plants were dormant. Treatments such as thiourea sprays of growing seedlings and chilling of dormant seedlings enhanced bud break and RRP. Potassium indolebutyrate applied to the root system promoted RRP of pistacia seedlings but did not eliminate the seasonal variation of RRP. Potassium indolebutyrate could replace the influence of buds only when seedlings were not in a dormant condition. Sucrose feeding via the stem substantially increased RRP at spring bud break. The results indicate that the dormant condition of buds and the availability of carbohydrates are the factors controlling the RRP of bare root transplanted pistacias.
L. Zhang, J.R. Livingstone, Y. Tarui, and E. Hirasawa
postproduction Postharvest Biol. Technol. 26 221 229 10.1016/S0925-5214(02)00010-8 Morcuende, R. Krapp, A. Hurry, V. Stitt, M. 1998 Sucrose-feeding leads to increased rates of nitrate assimilation, increased rates of α-oxoglutarate synthesis, and increased
William Sciarappa, Sridhar Polavarapu, James Barry, Peter Oudemans, Mark Ehlenfeldt, Gary Pavlis, Dean Polk, and Robert Holdcraft
commercially available as GF-120 NF Naturalyte Fruit Fly Bait, has ammonia-based attractants, a sucrose feeding stimulant, and a toxicant (spinosad). GF-120 also shows promise as a perimeter spray when pest populations invade from adjacent fields or forests
Shilun Gao, Yuan Gao, Ying Yang, Liming Jia, and Xuehuang Weng
.2.335 Mitra, S. Pereira, L.S. Pathak, P. Majumdar, D. 2005 Fruit abscission pattern of lychee cultivars Acta Hort. 665 215 218 https://doi.org/10.17660/ActaHortic.2005.665.24 Morcuende, R. Krapp, A. Hurry, V. Stitt, M. 1998 Sucrose-feeding