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Xiao-min Liu, Xin-zhi Zhang, Yi-min Shi, and Dong-qin Tang

resources ( Franco et al., 2001 ; Zhang and Dai, 2010 ). The methods for analysis of genetic diversity in plants were well developed in the last decades, commonly based on the morphological characteristics, seed proteins, isozymes, and DNA markers ( Gepts

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Robert R. Shortell, William A. Meyer, and Stacy A. Bonos

characterize recently developed Kentucky bluegrass cultivars that are or will become commercially available. Morphological and agronomic characteristics are used by breeders in the development of improved cultivars and by managers for specific cultivar

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Kathryn Homa, William P. Barney, Daniel L. Ward, Christian A. Wyenandt, and James E. Simon

morphological characteristics such as stomata density and leaf curvature influence infection of P. belbahrii in different Ocimum species, and if so, could be effective visual markers for screening in plant breeding. The large morphological variations in the

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Ying Gao, Hao Liu, and Dong Pei

)], and hybrid poplar [ Populus alba × ( P. davidiana × P. simonii ) × P. tomentosa ( Dong et al., 2012 )]. Previous attempts have been made to establish the relationships among the morphological characteristics, physiology, and histogenesis of

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Sylvia J. Brooks and Paul M. Lyrene

Morphological characteristics of many derivatives from Vaccinium arboreum Marsh × Vaccinium section Cyanococcus crosses were studied. The purpose of the study was to determine if V. arboreum traits were being inherited and expressed in hybrid progeny and to identify characteristics that would enable hybrid field identification. This study focused on the F1 hybrids of V. darrowi Camp × V. arboreum (F1 hybrids) and the open-pollinated progeny of the F1 hybrids [mother is known (MIK)]. Also included in the study were the parents: V. darrowi, V. arboreum, and V. corymbosum L. (pollen parent of the MIKs). Many leaf, flower, and fruit characteristics were measured for all five taxa. Leaf characteristics included length, width, and presence or absence of stalked glands, pubescence, and marginal bump glands. The floral characteristics measured were corolla length and width, corolla aperture, pedicel length, peduncle length, bracteole length and width, and the presence or absence of anther awns and bracteoles. Berry and seed mass were the fruit characteristics investigated. Four unique V. arboreum traits were found to be expressed in the F1 and MIK hybrid populations. These were the presence of anther awns, large seed size, bracteole shape, and marginal glands. These traits should permit field identification of hybrid plants.

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Wol-Soo Kim* and Jin-Ho Choi

The stone cells events in the process of lignifications of plant tissues in flesh of Asian pear have been growing as a depressing factor of fruit quality. Therefore, these studies were carried out to search the effect of stone cells on fruit quality, to investigate the anatomical characteristics, such as formative period and distribution of stone cell, to seek forming causes, and to determine the effects of drought stress and calcium foliar application on the formation of stone cell. Fruit quality as contents of the stone cells, such as texture profile, reducing sugars, firmness, and fruit size, were determined. During the growing season of 2002 and 2003, samples for anatomical investigations were taken periodically in Pyrus pyriforia cv. Niitaka, Pyrus communis cv. Bartlett and Pyrus ussiriansis cv. Yari. The morphology of stone cell in the fruit flesh was observed by using optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM).

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I.E. Yates and Darrell Sparks

External “morphological characteristics of catkins from one protogynous (`Stuart') and one protandrous (`Desirable') cultivar of pecan [Carya illinoensis Wangenh.) C. Koch] were examined to define markers of cellular differentiation in the anthers. The angle between the catkin rachis and the bract, visibility of the bracteole, rachis, and anther, and anther color proved to be markers by which development could be categorized into five stages. `Stuart' catkins with bracts as the only externally visible portion of the floret (Stage I) commonly had two locules in each anther lobe. When bracteoles became externally visible (Stage II), cellular specialization had occurred to form a central core containing reproductive cells and tapetal cells differentiated and separated from the exterior layers of the anther wall. Disintegration of tapetal cells and thickening of endothecium eel! walls occurred as the angle between the rachis and bract increased to 45° (Stage III). The anther wall was reduced to only two cell layers, epidermis and endothecium, as the anthers became visible (Stage IV). The pollen grains were mature when the anthers developed a yellowish tinge (Stage V) just before anther dehiscence. Tapetal cells had developed distinguishing traits in anthers of Stage I `Desirable' catkins and endothecial cells of Stage II. Internal anther development was similar for both cultivars from Stages III-V. Trichomes, a common feature-on the surface of the staminate floral parts, became less dense with proximity of the floral parts to the interior of the floret and with catkin maturity.

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Natasha Kovacheva, Krasimir Rusanov, Valtcho Jeliazkov (Zheljazkov), and Nedko Nedkov

Bulgaria is famous for its 330-year-old-tradition in rose oil production, which is based on the Kazanluk rose (Rosa damascena Mill. f. trigintipetala Dieck.). The Bulgarian rose oil (otto) is recognized as the ultimate rose oil. For successful selection and breeding work of oil-bearing roses, information is needed on the variation of morphological and phenological characteristics and essential oil composition of locally available genotypes. We estimated the correlation coefficients between yields and morphological characteristics of 15 genotypes of Bulgarian oil-bearing rose. It was found that rose yields depended mostly on the number of flowers, the number of flower branches per bush, and the weight of individual flowers (r = 0.99, 0.88, and 0.84, respectively). Also, we established correlations between the concentrations of various essential oil constituents of the Bulgarian rose oil. Generally, higher concentration of citronellol + nerol was associated with lower concentration of geraniol and stereo-terpens (r = –0.76 and –0.59, respectively). Also, higher concentration of citronellol + nerol was positively correlated to increased concentration of terpene aldehydes (r = 0.63) and esters (r = 0.48). The geraniol concentration was positively correlated to stearoptenes (r = 0.57). Both morphological characteristics and essential oil constituents should be used for further selection of high-yielding cultivars with desirable essential oil composition.

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Susan H. Gordon and Richard J. Hull

Frequent winter injury to flower buds is a major deterrent to the widespread landscape use of evergreen azaleas in the northern United States and southern Canada. Field observations indicate that azalea cultivars differ greatly in their capacity for cold acclimation during the fall. Azaleas also express wide variation in morphological features, such as Ieaf number, density, percent abscission, twig Iength, flower bud development rate, number or bud scales, and petal color. We attempted to correlate these characteristics with the establishment of flower bud cold tolerance during the fall season. Young (3-year-old) plants of more than 60 azalea cultivars were investigated under nursery conditions. Twigs were subjected to controlled freezing to quantify frost tolerance of flower buds. Percent live florets per bud and number of dead florets per bud were correlated with morphological characters. Floret development (floret Iength and style Iength) correlated positively with cold acclimation. Stem and Ieaf characters showed no consistent correlation with bud cold tolerance. Petal coloration, although not expressed at time of study, also correlated with cold acclimation. The extent of flower bud development proved to be the best indicator of fall and early winter frost tolerance.

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Wol-Soo Kim* and Jin-Ho Choi

The stone cells are observed in the process of lignifications of tissues in flesh of pear as a depressing factor of fruit quality. These studies were carried out to search the effect of stone cells on fruit quality, to investigate the anatomical characteristics, such as formative period and distribution of stone cell, to seek forming causes. During the growing seasons of 2002 and 2003, samples for anatomical investigations were taken periodically in Pyrus pyriforia cv. Niitaka, P. communis cv. Bartlett and P. ussiriansis cv. Yari. The morphology of stone cell in the fruit flesh was observed by using optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). By optical microscope, stone cell observed first from 14 days after full bloom. The adjacent cells to stone cell was first showed spherical type on initial forming stage but showed radial form at 90 days after full bloom. The shape of stone cell inspected by SEM was like a cluster and its size was various. By using TEM, components of stone cell, such as nucleus and vacuole, and secondary cell wall thickening were observed, so it could consider that the stone cell is living thing. The largest amount of stone cell clusters existed beneath fruit skin.