shoots of cascade huckleberry, mountain huckleberry, and oval-leaf bilberry using a low concentration nutrient medium containing zeatin. Multiple shoot regeneration can be obtained using leaf and stem explants from in vitro-grown shoots by incorporating 9
Yousef I. Dlaigen, A. E. Said, and M.A. El-Hamady
Several experiments were conducted in this investigation with the objective of determining the chemical components and the physical state of an optimal medium for the growth and elongation of excised date palm, cv Sukkari, roots. The chemical tests carried out included: Comparison of (MS)-salts with “White's”-salts mixture and different concentrations of (MS)-salts and its chelated iron; sugars; Modified White's Organics; inositol; adenine sulfate; growth regulators; and some antioxidants. The physical tests, on the other hand, included comparison of the growth and elongation of cultured roots in a liquid or on solidified nutrient media. The effects of various pH values were also tested. Roots were cultured in basal nutrient media composed of: (MS)-salts mixture, and (in mg·liter–1): NaH2PO4·H2O, 170; sucrose, 30,000; inositol, 200; Modified White's Organics; adenine sulfate, 120; activated charcoal, 1500; (2,4-D), 1; kinetin, 2. pH was adjusted at 5.7 ± 01. (MS)-salts mixture was found to be superior to “White's”-salts. No significant difference was observed between (1/2MS) and full-strength (MS)-salts. However, twice the concentration was found to be inhibitory. The normal concentration of (MS)-Fe was found to be optimum for root growth and elongation. The optimal concentration most suitable for the growth and elongation of excised date palm roots has been determined for each of: sugars; Modified White's Organics; inositol; and adenine sulfate. The only growth regulator that needs to be added to the nutrient medium is 2,4-D at 0.1–1.0 mg·liter–1. The study showed the importance of the inclusion of activated charcoal to the nutrient medium. The growth and elongation of roots were both stimulated at all concentrations tested. (PVP), on the other hand, was inhibitory at all concentrations tested. Shaken liquid media was recommended for better root growth and elongation at pH 7.0–8.0. Incidentally, the medium developed was found to support the growth and elongation of roots excised from two other cultivars, namely `Khudri' and `Khaias'.
Scott J. Nissen and Ellen G. Sutter
The relative stabilities of IAA and IBA under various tissue culture procedures were determined. IBA was significantly more stable than IAA to autoclaving. IBA was also found to be more stable than IAA in liquid Murashige and Skoog medium (MS) under growth chamber conditions. The stabilities of IBA and IAA were similar in agar-solidified MS. Light provided by cool-white fluorescent bulbs promoted degradation of IAA and IBA in both liquid and agar media. Activated charcoal in concentrations as high as 5% was found to adsorb more than 97% of IAA and IBA in liquid MS. These results have important implications for the preparation, storage, and handling of IBA and IAA in plant tissue culture. Chemical names used: indole-3-acetic acid (IAA); indole-3-butyric acid (IBA).
Brent Tisserat and Paul Galletta
Plans are presented for the construction of a three-channel reversible peristaltic pump that can operate at a rate of 45 ml/minute per channel. The cost of this peristaltic pump is about $84 compared to $620 for a commercially available peristaltic pump of similar design and capability. An electronic control scheme for pump operation is presented also.
Davut Keleş, Hasan Pınar, Atilla Ata, Hatıra Taşkın, Serhat Yıldız, and Saadet Büyükalaca
, and then rinsed four times in sterile distilled water. After sterilization, the flower buds were dissected, the filaments were removed, and the anthers were placed on nutrient medium in 6-cm-diameter glass petri dishes using sterile forceps and
Davut Keleş, Ceren Özcan, Hasan Pınar, Atilla Ata, Nihal Denli, Namık Kemal Yücel, Hatıra Taşkın, and Saadet Büyükalaca
rinsed five times with sterile water. After sterilization, anthers were removed from flower buds with sterile forceps and scalpels, and were placed into 6-cm diameter sterile glass petri dishes containing nutrient medium. For anther culture experiments
Saila T. Karhu
Microshoots of `McIntosh' apple (Malus domestica Borkh.) were grown on Murashige-Skoog (MS) nutrient medium supplemented with either sucrose or sorbitol or with sucrose and an elevated level of cytokinin. Shoot growth was recorded and concentrations of fructose, glucose, sorbitol, and sucrose were analyzed in nutrient media and shoots during a 6-week subculture period. Axillary branching was stimulated by high cytokinin and sorbitol media, with increased biomass production and carbohydrate use on the high-BA medium only. The sucrose in the nutrient medium was hydrolyzed to fructose and glucose, which were equally taken up by shoots. Sorbitol was taken up somewhat less effectively. The elevated level of BA decreased sucrose hydrolysis in the nutrient medium. There were high concentrations of sorbitol in shoots grown on the sorbitol medium, and sorbitol also accumulated at the end of the culture period in shoots grown on sucrose. The amount of sucrose was low, and glucose was more abundant than fructose in microshoots. The starch content of leaves was not affected by treatments or sampling time. Chemical names used: N6-benzyladenine (BA).
Samir C. Debnath
The growth and development of lingonberry (Vaccinium vitis-idaea L.) plants propagated either by conventional softwood cuttings or by in vitro shoot proliferation from nodal explants and by shoot regeneration from excised leaves of micropropagated shoots, were studied in cultivars `Regal', `Splendor', and `Erntedank'. Significant differences were observed between the treatments. After 3 years of growth, the in vitro-derived plants produced more stems, leaves, and rhizomes than the conventional cuttings which rarely produced rhizomes. In vitro culture on nutrient medium apparently induces the juvenile branching characteristics that favor rhizome production. This increase in vegetative growth and rhizome yield of in vitro-derived plants over stem cuttings varied among genotypes.
Brent Tisserat, Danny Jones, and Paul D. Galletta
Nutrient medium can be sterilized using a household-type microwave oven. The required microwave treatment time was influenced by the oven's microwave power intensity (70 to 700 W), vessel type, volume of medium employed, and the presence of energy sink water reservoirs (ESWR). Growth rates of strawberry (Fragaria vesca L.) shootlets, lemon [Citrus limon (L.) Burm. f.] fruit halves, or carrot (Daucus carota L.) callus cultured on either microwaved or autoclaved media were similar. Microwaving and autoclaving appeared to reduce GA3 activity compared with medium containing filter sterilized GA3. Chemical name used: gibberellic acid (GA3).
Mark P. Bridgen
Traditional and biotechnological breeding techniques are being united to develop exciting new plants and to improve existing cultivated plants by introducing natural variability from germplasm resources. Intervarietal, interspecific and intergeneric crosses can be accomplished by using plant embryo culture techniques, sometimes also referred to as embryo rescue. Embryo culture involves the isolation and growth of immature or mature zygotic embryos under sterile conditions on an aseptic nutrient medium with the goal of obtaining a viable plant. The technique depends on isolating the embryo without injury, formulating a suitable nutrient medium, and inducing continued embryogenic growth and seedling formation. The culture of immature embryos is used to rescue embryos from hybrid crosses that were once thought to be incompatible because they would normally abort or not undergo the progressive sequence of ontogeny. The culture of mature embryos from ripened seeds is used to eliminate seed germination inhibitors, to overcome dormancy restrictions, or to shorten the breeding cycle. New and exciting cultivars of Alstroemeria, also known as Lily-of-the-Incas, Inca Lily, or Peruvian Lily, have been bred by using zygotic embryo culture; these techniques and applications will be discussed.