Search Results

You are looking at 1 - 10 of 501 items for :

  • Refine by Access: All x
Clear All
Free access

Madhulika Sagaram, Leonardo Lombardini, and L.J. Grauke

differences in the lengths of growing season at their origins ( Wood et al., 1998 ). Studies conducted on ponderosa pine ( Pinus ponderosa Dougl. ex Laws) reported intraspecific variation for anatomical and physiological traits such as stomatal density [SD

Free access

Tripti Vashisth, D. Scott NeSmith, and Anish Malladi

blueberry genotypes differ in the ease of fruit detachment, understanding the morphological, anatomical, physiological, and molecular bases of such differences in fruit detachment across blueberry genotypes can potentially aid in the development of cultivars

Free access

Ying Gao, Hao Liu, and Dong Pei

. 2012), we sampled 20 staminate flowers from the midpoint of catkin development for anatomical observation and IAA immunohistochemical study. Morphological observation of catkin differentiation. Branches with catkins were taken to the laboratory. We used

Free access

Carlos H. Crisosto, Juvenal G. Luza, David Garner, Guiwen Cheng, and Kevin Day

Peach and nectarine skin discoloration or inking (SD) has become a fruit industry problem in the last decade. Spots on the skin may be black, tan, purple or brown and vary in shape. SD was related with physical abuse of the fruit occurring during handling (harvest and transport operations) within the orchard.

An anatomical study comparing healthy and damaged (black and brown) tissue of different peach and nectarine varieties was done with the Scanning Electron Microscope (SEM) and Light Microscope (LM). This study indicated that only exocarp cell (epiderm and cuticle) damage was associated with SD. The internal compartmentation of the damaged cells was often disrupted with the contents of the cytoplasm and vacuole mixed and expelled. Mesocarp cells were always intact and turgid. The same anatomical and visible tissue injury symptoms were induced on fruit by abrasion treatments.

Free access

Madhulika Sagaram, Leonardo Lombardini, and Larry Grauke

An assessment of anatomical traits of pecan cultivars (`Pawnee', `Mohawk', and `Starking hardy giant') collected from three locations (Tifton, Ga.; Chetopa, Kans.; and Stillwater, Okla.) was conducted at Texas A&M University. The objective of the study was to provide an understanding of patterns of geographic variation within the natural range for anatomical (stomatal density, stomatal index, and epidermal cell density) traits. Microscopy using acetate casts was used as the means to investigate the patterns of variation in the epidermal characteristics of pecan leaf. `Starking hardy giant' had the greatest number of stomates/cm2 (46,229, 47,807, and 45,990 at Tifton, Chetopa, and Stillwater, respectively) while `Mohawk' had the least (37,397, 36,217, and 35,305). `Pawnee' had the greatest number of epidermal cells/cm2 (251,806, 250,098 and 254,883 at Tifton, Chetopa, and Stillwater, respectively) while `Starking hardy giant' had the least (141,699, 138,405, and 142,155). Differences in stomatal index were observed between the three cultivars at Tifton and Stillwater. No differences in stomatal index were observed between `Pawnee' and `Mohawk' at Chetopa. The study showed that stomatal density as well as epidermal cell density of all the tested cultivars were significantly different (P < 0.05) at a particular location but no differences were observed in a given cultivar grown at different locations.

Free access

Tekalign Tsegaw, S. Hammes, and J. Robbertse

Potato (Solanum tuberosum L.) treatment with paclobutrazol resulted in short and compact plants having dark green and thicker leaves, and wider stem and root diameters. Investigating the underlying anatomical modifications in response to the treatment was the objective of the study. Plants of potato cultivar BP 1 were treated with 0, 45.0, 67.5, and 90.0 mg paclobutrazol per plant as a foliar spray. A month after treatment leaf, stem and root materials were taken from the control and plants treated with 67.5 mg paclobutrazol, and histological observations were made using light microscope. Leaves of treated plants showed an increased chlorophyll a and b contents, thicker epicuticular wax layer, elongated and thicker epidermal, palisade and spongy mesophyll cells. paclobutrazol increased stem diameter by about 58% due to induction of thicker cortex, larger vascular bundles, and wider pith diameter associated with larger pith cells. Widening the cortex and the induction of more secondary xylem vessels in response to paclobutrazol treatment increased the root diameter by about 52%. Paclobutrazol treatment remarkably increased the accumulation of starch granules in the stem pith cells and cortical cells of the stem and root. This study is similar to the other relevant studies in reporting an increased leaf thickness, and stem and root diameters; however, most of the underlying anatomical modifications described above have not been reported previously.

Free access

Ro-Na Bae, Ki-Woo Kim, Tae-Choon Kim, and Seung-Koo Lee

Anatomical observations of anthocyanin rich cells in `Fuji' apple skins were carried out by light microscopy and electron microscopy. Apple skins with fully developed red color had more layers of anthocyanin-containing epidermal cells than those of green skins. The density of anthocyanin was high in cells of the outer layer of the fruit skins and gradually decreased inward to the flesh. Anthocyanins were frequently found in clusters or in agglomerations that were round in the epidermal cells of the red skins. They accumulated in the inner side of developed vacuoles. Transmission and scanning electron microscopy revealed that the shapes of anthocyanins were cluster style, indeterminable forms, or complete spheres. Anthocyanin seemed to be synthesized around the tonoplast and condensed on the inward side of the vacuole. There was no distinct envelope membrane on the anthocyanin granule in the vacuoles of apple skin cells.

Free access

Ehiorobo Izekor and James O. Garner Jr.

Selected physiological and anatomical characteristics of four chilling-tolerant sweetpotato genotypes were evaluated. Although the genotypes were considered highly tolerant to chilling, it was proposed that differences in their mechanism for tolerance existed. A genotype temperature interaction for chlorophyll fluorescence ratio was observed when the plants were exposed to 5 °C. Genotype differences were found for electrolyte leakage and peroxidase activity. There were no differences found for fatty acid percentage composition of the glycolipid or the phospholipid fraction from leaf samples. There were no differences in diffusive resistance and transpiration rate among the genotypes; however, stomata density, leaf shrinkage, and specific leaf weight differed among the genotypes. Differences were also found among the genotypes for percent leaf dry weight, leaf thickness, and cellular structure of the leaf. It was concluded that the basis or mechanism for chilling tolerance was not the same for the four genotypes tested; therefore, combining traits for tolerance could lead to higher tolerance levels.

Free access

Naveen Kumar, Fnu Kiran, and Ed Etxeberria

aimed at defining the dynamic changes in fibrous root anatomy and consequent collapse of phloem in HLB-infected citrus. To accomplish our goals, we sampled different root orders and evaluated the C Las-induced anatomical changes to further understand

Free access

Carlos H. Crisosto, R. Scott Johnson, Juvenal Luza, and Kevin Day

Skin discoloration (SD) formation in peach [Prunus persica (L.) Batsch] and nectarine [Prunus persica (L.) Batsch, var. nectarine] was related to physical damage (abrasion) to the fruit during fruit handling (harvest and hauling operations) within the orchard and during transport to the packinghouse. Vibration and rubbing treatments increased SD formation indicating that tissue damage is involved in SD formation. Anatomical studies comparing sound and SD-injured tissues done by scanning electron and light microscopy indicated that very-low-intensity physical damage could induce brown and/or black spots because of cell disruption in the epidermal and hypodermal layers. The fact that injury was specific to the exocarp tissues (cuticle, epidermis, and hypodermis), and that mesocarp tissue located below the exocarp cells remained sound and turgid, indicated that abrasion injury is associated with SD. Similar types of visible and anatomical injury characteristics were induced by a rubbing treatment, demonstrating that physical abrasion damage affecting just exocarp cells was enough to induce SD: