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Xue-Min Hou, Zi-Hua Wang, Xi-Min Deng, and Guo-Hui Li

centrifugal force to apple cortex samples to obtain a P-V curve of cortex tissue by calculating rotation-created water potential corresponding to the measured volume of extracted water. Determining the water relation parameters of fruit by the centrifuge

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Sin-Ae Park, Chorong Song, Ji-Young Choi, Ki-Cheol Son, and Yoshifumi Miyazaki

prefrontal cortex of the brain ( Jöbsis, 1977 ; Perrey, 2008 ). The biological effects of viewing foliage plants on the wellbeing of individuals are not well understood. Because of the advantages of using NIRS to assess brain activity, the objective of this

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Mingbo Qin, Shanqiang Ke, Abbas Lafta, Murray E. Duysen, and Chiwon W. Lee

The relative concentrations of sucrose, glucose, and starch in the xylem and cortex tissues of carrot (Daucus carota) roots were evaluated after harvest and during storage. For the three cultivars (Apache, Bolero, Danvers 126) tested, the cortex tissue contained 76.6, 49.1, and 33.6 mg·g–1 dry weight of sucrose, glucose, and starch, respectively. In comparison, the average contents of sucrose, glucose, and starch in xylem tissues were 57.4, 52.4, and 11.6 mg·g–1 dry weight, respectively. In general, cortex tissue contained higher concentrations of sucrose and starch than the xylem tissues. The glucose concentrations in cortex and xylem were similar. In `Apache', for example, the cortex tissue contained 40% and 57% higher concentrations of sucrose and starch, respectively, than the xylem tissues, whereas glucose content of the cortex was only 7.5% higher than that of the xylem. Since sweetness is largely influenced by sucrose, the relative volume of cortex to xylem must be considered in evaluating carrot cultivars for sweet taste.

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Rachel S. Leisso, Ines Hanrahan, James P. Mattheis, and David R. Rudell

CI of ‘Honeycrisp’ apple fruit is often manifested as either soft scald, which is characterized by sunken, ribbon-like brown regions of the peel ( Barker, 1938 ; Snowdon, 1990 ), or soggy breakdown, a cortex disorder characterized by similarly

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Joseph K. Peterson, Howard F. Harrison, and Maurice E. Snook

After removal of the periderm, cortex tissue of the sweetpotato cultivar Regal was collected. Polar extracts of this tissue strongly inhibited germination of proso-millet seed. C18 preparative, step-gradient chromatography (H2O → 100% methanol) gave some 50+ fractions, all of which were assayed for inhibitory properties. Analytical HPLC, using diode array detection and signal processing, showed the presence of chlorogenic, p-coumaric and caffeic acid, scopolin and some unknown phenolic acids. Most fractions were inhibitory to some degree; however, the least polar ones (in 90% and 100% methanol), containing unknown compounds, were most inhibitory. Semi-prep HPLC of these fractions produced eight major peaks (λmax at 210–213 nm, λ2 at 281–284 nm). In our bioassays, the compounds produced 50% inhibition of proso-millet seed germination at ≈60 ppm. It is likely that these compounds contribute significantly to the allelopathic properties of sweetpotato.

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Bingru Huang and David M. Eissenstat

In Citrus L. sp., specific root length of whole root systems has been correlated positively with root hydraulic conductivity, but there is little mechanistic understanding of the causes for this association. The hydraulic conductivity of individual roots in relation to root anatomical characteristics in seedlings of three citrus rootstocks [sour orange (SO) (Citrus aurantium L.), trifoliate orange (TO) (Poncirus trifoliate (L.) Raf.), and Swingle citrumelo (SC) (C. paradisi Macf. × P. trifoliata)] that vary widely in specific root length (SRL) was measured. Among fibrous roots, first-order and secondorder laterals were examined. Relative differences among rootstocks in the overall hydraulic conductivity (LP) and radial conductivity (LR) for individual 1-month-old and 6-month-old second- and first-order roots generally were consistent with hydraulic conductivity determined previously for entire root systems. There were no significant differences in axial conductance per unit pressure (Kh) in either first- or second-order roots among the rootstocks. This was consistent with the similarity in number and diameter of xylem vessels. One-month-old second-order roots had no suberized exodermis but varied in cortical radius. Six-month-old second-order roots of TO, however, had more nonsuberized cells (passage cells) in the exodermis than roots of SC and SO, although the cortical radius of SC and SO roots were not different. Compared to 6-month-old second-order roots, 1-month-old second-order roots had much higher LP and LR but lower Kh. Differences in overall root hydraulic conductivity among the citrus rootstocks were mainly related to structural differences in the radial pathway for water movement, suggesting that radial hydraulic conductivity was the primary determining factor of water uptake in citrus rootstocks.

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Thomas E. Marler, Anders Lindström, and Jack B. Fisher

stems have concentric cylinders of vascular tissue that contain soft, parenchymatous xylem tissue and little lignified tissue with each new additional cylinder differentiating at the base of the stem between the cortex and the youngest pre

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Jinwook Lee, James P. Mattheis, and David R. Rudell

inconsistently associated with fruit size ( Lee et al., 2013 ). Symptoms in untreated fruit can appear first as diffuse browning in the stem-end cortex tissue, and symptoms can progress through the equator and into the calyx-end cortex tissue ( Lee et al., 2013

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Jianguo Li, Hong Zhu, and Rongcai Yuan

was to examine the expression of genes involved in ethylene biosynthesis, ethylene perception, and cell wall degradation in the fruit abscission zone and fruit cortex of ‘Golden Delicious’ and ‘Fuji’ apples during PFA and fruit ripening and to

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Jack B. Fisher, Anders Lindström, and Thomas E. Marler

differentiating at the base of the stem between the cortex and the peripheral youngest existing cylinder ( Bork, 1990 ; Chamberlain, 1935 ; Terrazas, 1991 ). A persistent parenchymatous cortex is present in old, thickened stems and is not replaced by phloem or