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David M. Czarnecki II, Amanda J. Hershberger, Carol D. Robacker, David G. Clark, and Zhanao Deng

pollen that can be transferred onto native lantana’s flowers by pollinators. Dehgan (2006) indicated the existence of a wide range of pollen stainability (from less than 5% in Patriot™ ‘Sunburst’ to more than 80% in ‘Professor Raoux’) in L . camara

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Carolina A. Torres, Omar Hernandez, Maria A. Moya-León, Ivan Razmilic, and David R. Rudell

Schrader, 2012 ; Yuri et al., 2000b ). Climatic conditions in these regions can elevate photooxidative and heat stress throughout the growing season affecting the tree and fruit physiology. Skin browning or “stain” can develop on ‘Fuji’ apples during cold

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Henry R. Owen and A. Raymond Miller

A factorial combination of pretreatments, fixatives, and stains was examined to identify the best available method for staining the chromosomes of strawberry (Fragaria × ananassa Duch. `Chandler') root-tip cells. Three pretreatments (a -bromonaphthalene, p -dichlorobenzene, and 8-hydroxyquinoline), three fixatives (Farmer's fluid, Carnoy's fluid, and Newcomer's fluid), and five stains (acetocarmine, alcoholic hydrochloric-acid carmine, altered carbol fuchsin, lacto-propionic orcein, and leucobasic fuchsin) were tested. Pretreatment with either a -bromonaphthalene (saturated aqueous) or 8-hydroxyquinoline (2 mm) for 5 hours at 14C, overnight fixation in Farmer's fluid, hydrolysis in 1 n HCl (15 minutes at 60C), and staining with altered carbol fuchsin produced chromosome preparations superior to other treatment combinations. Treatment with a-bromonaphthalene, Farmer's fluid, and alcoholic hydrochloric-acid carmine (2 days at 25C) also produced acceptable chromosome preparations.

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Asma Ziauddin, Mingsheng Peng, and David J. Wolyn

Clear visualization of asparagus (Asparagus officinalis L.) microspore nuclei with common stains such as acetocarmine or DAPI is difficult, hindering cytological analyses. The addition of saturated aqueous ferric chloride solution to Carnoy's I fixative (30 μL·mL-1) resulted in clear visualization of nuclei. A distinct nucleus was observed in uninucleate cells and the vegetative and generative nuclei were clearly visible in binucleate microspores. This method can be used reliably for determination of asparagus microspore developmental stage. Chemical name used: 4′,6-diamidino-2-phenylindole-2HCL (DAPI).

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Brigitte D. Crawford, John M. Dole, and Ben A. Bergmann

been harvested) from the same stock plants, or stock plant age. This study had two main objectives. The first was to determine if cutting quality and rooting success of ‘Stained Glass’ coleus are influenced by season, cutting week within a propagation

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Katsumi Suzuki, Tadashi Tsukaguchi, Hiroyuki Takeda, and Yoshinobu Egawa

Pod yield of `Kentucky Wonder' green bean (Phaseolus vulgaris L.) decreased at high temperatures due to a reduction of pod set. A highly positive correlation was observed between pod set and pollen stainability in flowers that were affected by heat stress about 10 days before anthesis. Pollen stainability was decreased by heat stress applied 8 to 11 days before flowering under controlled environment conditions. When mean air temperature during this period exceeded 28 °C, pollen stainability decreased under field conditions. Low pollen stainability indicated sensitivity to high temperatures about 10 days before flowering. A heat-tolerant cultivar showed higher pollen stainability than did heat-sensitive cultivars under high temperatures. These results demonstrated that heat tolerance at an early reproductive stage could be evaluated by analyzing pollen stainability using flowers developed under high temperatures.

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Connie L. Fisk, Yanyun Zhao, and Bernadine C. Strik

Iodine staining of starch was explored as a harvest index for hardy kiwifruit (Actinidia arguta). Weekly from 2 Sept. to 14 Oct. 2005, the cut surfaces of 20 halved fruit were dipped in an iodine solution and the staining intensity was measured using digital photography and color analysis. Harvest date had a significant effect on percent soluble solids and each of the color readings (L*, a*, b*, and chroma) before and after staining. Fruit harvested later in the season had less starch and thus were lighter in color. However, an observable color difference was only visually apparent weeks after commercial harvest is recommended based on percent soluble solids. Therefore, while the technique can distinguish the conversion of starch to sugar in hardy kiwifruit berries, it cannot be used as a harvest index.

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Henry R. Owen and A. Raymond Miller

A comparison of pretreatment, fixing, and staining methods for root tips of Fragaria × ananassa (2n=8x=56), a polyploid species with small chromosomes, was made to facilitate chromosome counting. Three pretreatments (8-hydroxyquinoline, α-bromonaphthalene, and p-dichlorobenzene), three fixatives (Farmer's, Carnoy's, and Newcomer's), and five stains (acetocarmine, lacto-propionic orcein, leucobasic fuchsin, altered carbol fuchsin, and alcoholic hydrochloric-acid carmine) were examined in a factorial design to determine which treatment combination produced the best chromosome preparation. Field propagated runners were grown in sand under greenhouse conditions with supplemental lighting to produce root tips for late morning collection. The treatment combinations of α-bromonaphthalene or 8-hydroxyquinoline, Farmer's fixative, and altered carbol fuchsin, or the combination of α-bromonaphthalene, Farmer's fixative, and alcoholic hydrochloric-acid carmine produced the most intensely-stained and well-defined preparations.

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Richard G. Novy and Nicholi Vorsa

Cranberry (Vaccinium macrocarpon Ait.) has few qualitative, morphological characteristics that can be used to reliably distinguish among cultivars. Fifty-two silver-stained random amplified polymorphic DNAs (ssRAPDs) were used to assess genetic heterogeneity and relatedness within accessions of four major cranberry cultivars (`Early Black', `Howes', `McFarlin', and `Searles'). Rather than being represented by one genotype, as might be expected in an asexually propagated crop, each cultivar was represented by multiple genotypes, which in many cases did not appear to be closely related to one another. The intracultivar heterogeneity was often so extreme that clonal representatives of a cultivar would group with representatives of other cultivars following cluster analysis. Of the total ssRAPD variation, 9.7% could be attributed to variation among the four cultivar groups and 90.3% to variation within the cultivars. `Howes' was the only cultivar in which a consensus DNA fingerprint among regional representatives could be identified.

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Jose Lopez-Medina, B.J. Murphy, and J.N. Moore

Isozyme staining and SDS-PAGE of soluble proteins were performed using leaf homogenates from 6- to 8-month-old field-grown seedlings resulting from the cross of either `Heritage' or `Nova' raspberry with ARK-577 diploid blackberry, the latter used as the pollen-donor parent. Four enzyme systems were tested: ADH, PGM, MDH, and PGI. Of these, ADH and PGM did not show any activity; MDH was monomorphic in both raspberry and blackberry parents, with activity at the same migration distance. PGI was polymorphic in the two raspberry cultivars, showing three dimeric bands, but monomorphic in blackberry; the allele for PGI in blackberry being common to that allele coding for the most cathodal band in raspberry. This phenomenon, in addition to poor resolution of bands (due, perhaps to low enzyme activity) and evidence of accidental self-pollination in our populations, prevented us from positively identifying the hybrid offspring using isozymes. By SDS-PAGE of soluble proteins, two bands were detected that seemed to be unique to ARK-577 blackberry and were also expressed in some of the offspring, suggesting a hybrid origin of these seedlings. Morphological comparisons indicated that those seedlings possessing the two unique bands highly resemble the blackberry male parent, greatly supporting their hybrid origin. Unless additional analysis shows otherwise, SDS-PAGE can be used to identify Raspberry–Blackberry hybrids during their vegetative stage of development, and might prove applicable to other interspecific hybrids of Rubus.