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Steven J. Damon, Russell L. Groves and Michael J. Havey

replication as random. Plant weight was used as a covariate to account for a possible attraction of onion thrips to larger plants. Results and Discussion Epicuticular wax morphology. SEM micrographs ( Fig. 1 ) revealed no obvious wax crystals on glossy leaves

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Frank G. Bethea Jr., Dara Park, Andrew Mount, Nick Menchyk and Haibo Liu

scanning electron microscopy (SEM) (Hitachi SU6600 Field Emission SEM) at the Clemson Electron Microscopy Laboratory in Pendleton, SC. Leaves were harvested and fixed with carbon tape on aluminum stubs with adaxial side up. Leaves were allowed to air

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Chalita Sriladda, Heidi A. Kratsch, Steven R. Larson, Thomas A. Monaco, FenAnn Shen and Roger K. Kjelgren

plants grown from cuttings. Additionally, fine-scale morphological differences were compared through scanning electron microscopic (SEM) images. Three leaf punches per plant were collected from three plants of each species and the hybrid, and directly

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Yahya K. Al-Hinai and Teryl R. Roper

The effects of rootstock on growth of fruit cell number and size of `Gala' apple trees (Malus domestica Borkh) were investigated over three consecutive seasons (2000-02) growing on Malling 26 (M.26), Ottawa-3, Pajam-1, and Vineland (V)-605 rootstocks at the Peninsular Agricultural Research Station near Sturgeon Bay, WI. Fruit growth as a function of cell division and expansion was monitored from full bloom until harvest using scanning electron microscopy (SEM). Cell count and cell size measurements showed that rootstock had no affect on fruit growth and final size even when crop load effects were removed. Cell division ceased about 5 to 6 weeks after full bloom (WAFB) followed by cell expansion. Fruit size was positively correlated (r 2 = 0.85) with cell size, suggesting that differences in fruit size were primarily a result of changes in cell size rather than cell number or intercellular space (IS).

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X. Zhang, J.W. White and D.J. Beattie

Abbreviations: 18 SH, 18 h of high light treatment; 18 SL, 18 h of low light treatment; HPS, high pressure sodium; Nat, natural daylight; SEM, scanning electron microscope; VB, visible bud. 1 Graduate Assistant. 2 Professor. 3 Assistant Professor

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Hirofumi Terai, Alley E. Watada, Charles A. Murphy and William P. Wergin

Structural changes in chloroplasts of broccoli (Brassica oleracea L., Italica group) florets during senescence were examined using light microscopy, scanning electron microscopy (SEM) with freeze-fracture technique, and transmission electron microscopy (TEM) to better understand the process of chloroplast degradation, particularly at the advanced stage of senescence. Light microscopy revealed that chloroplasts, which initially were intact and green, became obscure in shape, and their color faded during senescence. Small, colored particles appeared in cells as the florets approached the final stage of senescence and became full- to dark-yellow in color. Scanning electron microscopy showed that stroma thylakoids in the chloroplast initially were parallel to each other and grana thylakoids were tightly stacked. As senescence advanced, the grana thylakoids degenerated and formed globules. The globules became larger by aggregation as senescence progressed, and the large globules, called “thylakoid plexus,” formed numerous vesicles. The vesicles ultimately were expelled into the cytosol, and the light microscope revealed many colored particles in the senescent cells. These results indicate that the degradation of chloroplasts in broccoli florets progresses systematically, with the final product being colored particles, which are visible in yellow broccoli sepal cells.

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P. Allan-Wojtas, K.A. Sanford, K.B. McRae and S. Carbyn

The apple industry worldwide would benefit from an improved and standardized description of fresh-apple textural quality. The description proposed here is unique in that it integrates structural, sensory, and consumer information. To demonstrate its benefits, 24 apple cultivars [Malus ×sylvestris (L.) Mill. var. domestica (Borkh..) Mansf.] were sampled over two harvest seasons and analyzed using microstructural and sensory techniques. Cultivars were selected to cover a range of known sensory textures, and microstructural profiles were compiled in parallel with sensory and instrumental studies. Each cultivar was pre pared for conventional scanning electron microscopy (SEM) observation using standard methods. Representative fruit from each cultivar were photographed at three magnifications to visualize fruit architecture, tissue relationships, and size, shape, and arrangement of cells within layers to compile the microstructural profile. A trained sensory panel evaluated the cultivars for crispness, surface coarseness, sponginess, hardness, juiciness, degree of melting, mealiness, and skin toughness while a consumer panel rated liking. This information was compiled into a texture profile. The microstructural and texture profiles were then combined into a cultivar profile for each sample. Cultivar profiles were collected to form a database; subtle similarities and differences among the 28 market-quality samples were interpreted and noted. With this technique, those structures with similar sensory properties can be identified with some form of microscopy. Clarifying and predicting the parameters that are related to textural quality in new cultivars will streamline the introduction process.

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F. Takeda, M. Wisniewski and D. M. Glenn

In previous work no difference was found in leaf water potential or solute potential between young guttating leaves and older non-guttating leaves of the same plant. This suggested that the absence of guttation in older leaves was associated with a plant resistance component in the hydathodes. Hydathodes of young, folded leaves contained water pores with various apertures and no signs of occlusion.. In expanded, young leaves, production of epicuticular waxes and excretion of some substance through the pores was observed in the hydathode region. By the time leaves had fully expanded the hydathodes had become brownish. The combination of wax deposition and excreted substance had formed plates of solid material covering water pores. These observations suggest that deposition of substances on top of pores contribute to occlusion of water pores in old leaves.

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Cevriye Mert

10 pollen grains at three different regions each. Scanning electron microscopy. After dehydration on a silica gel drier, small quantities of pollen grains were mounted on scanning electron microscopy (SEM) stubs and coated with gold–palladium (Polaron

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Cevriye Mert

regions for each grain. Scanning electron microscopy. After dehydration, the anthers and pollen grains were mounted on scanning electron microscopy (SEM) stubs, coated with gold–palladium (Polaron SC7620; VG Microtech, Uckfield, UK), and examined