baby food jars (5 × 9 cm) (Cosmo ® ) containing half strength MS basal medium without PGR. For all experiments, 8 g·L −1 agar and 25 g·L −1 sucrose were supplemented in the MS medium, and the pH was adjusted to 5.8 with 0.5 n NaOH or HCl before
Muhammad Irshad, Hafiz Muhammad Rizwan, Biswojit Debnath, Muhammad Anwar, Min Li, Shuang Liu, Bizhu He, and Dongliang Qiu
Melek Ekinci, Ertan Yildirim, Atilla Dursun, and Metin Turan
treatment were sprayed with 100 mL of each solution. Salt treatments. Salt treatments were established by adding 0, 50, and 100 m m of NaCl to a base complete nutrient solution (SoFertig) when the plants were transplanted. The composition of the SoFertig
Erin J. Yafuso and Paul R. Fisher
saturation and provide air-filled porosity for oxygen supply to roots, even when irrigated to CC ( Argo et al., 1996 ; DeBoodt and Verdonck, 1971 ). In a typical peat-based substrate, air porosity can be up to 32% by volume at CC in a 1-L container, but this
Thomas H. Yeager, Joseph K. von Merveldt, and Claudia A. Larsen
nutrient concentrations (NO 3 -N, P, and K) were determined according to standard procedures ( Analytical Research Laboratory, 2008 ) for Blocks 1 to 4. At experiment termination, visual appearances were observed and roots were washed of substrate and stems
Maria Luiza De Oliveira, James G. Thomson, and Ed Stover
were used in all rooting media. Root formation and root growth in ‘Carrizo’ citrange and ‘Washington Navel’ orange were significantly affected by basal salt formulation and the ionic strength of the medium ( Table 6 ). Roots induced on all strengths of
Horseradish (Armoracia rusticana) has one of the highest rates of postharvest weight loss among all vegetable crops. Postharvest studies were conducted to identify improved methods of extending the market life of fresh horseradish roots. Postharvest treatments included submerging or coating thoroughly washed and dried roots in chlorine (150 ppm), hydrogen dioxide (Storox), 2,6-dichloro-4-nitroaniline (Botran), carnauba-based wax, shellac-based wax, paraffin wax, and polyolefin shrink film (75–100 micron thickness). Two treatments, shrink wrapping and paraffin waxing, were superior in reducing postharvest weight loss and extending horseradish root market life. Roots from the non-paraffin waxed and nonshrink-wrapped treatments lost an average of 20% weight after only 4 days of ambient temperature storage. This resulted in significant root shriveling and unacceptable market appearance. Roots from the shrink wrapped treatments lost an average of 1% weight after 4 days of ambient temperature storage, while paraffin waxed roots lost about 3% weight. It is important to thoroughly dry the roots before shrink wrapping, to avoid moisture condensation on the inner surface of the film and subsequent microbial growth. All of the shrink-wrapped roots and paraffin waxed roots were marketable after 14 days of ambient storage, and no surface mold was detected. Less than 3% weight loss occurred after 14 days of ambient storage in all shrink-wrapped roots, while paraffin-waxed roots lost about 9% weight. Weight loss in the unwrapped roots from the other postharvest treatments ranged from an unacceptably high 44% to 48% after 14 days.
Richard Smith, Michael Cahn, Timothy Hartz, Patricia Love, and Barry Farrara
width of one bed and 1 m deep. A smooth face was prepared on the excavated area and a hand-pressurized sprayer was used to wash soil from exposed roots. The number of roots in each 20-cm depth increment was determined. Irrigation monitoring. To evaluate
Enaksha R. Wickremesinhe and Richard N. Arteca
Cephalotaxus harringtonia plants produce alkaloid compounds possessing antitumor properties, the major one being homoharringtonine. The purpose of this study was to produce roots from callus cultures developed earlier. Fast growing callus cultures were placed on MS basal salt medium with B-5 vitamins, 2% sucrose, 10 μM kinetin, 0.45 μM 2,4-D and 0.2% Gelrite. Upon subculture onto basal medium without hormones, we observed organogenesis of both shoots and roots. Roots were excised and established on basal medium without hormones. By subculturing two 2-inch root tips containing numerous visible laterals in liquid medium we were able to harvest 30 g of roots/250 ml flask after 3 weeks and 50 g/250 ml flask after 6 weeks. A 20-fold increase in fresh weight was achieved within 3 weeks when 15 grams of roots were initially seeded into a 3 liter air-sparged bioreactor. However, most of these roots appeared to be fleshy/swollen while root cultures established from half inch root tips grew slower but were normal in appearance. We arc currently in the process of establishing growth characteristics for these roots and assaying roots for the presence of these alkaloids.
A study was conducted to investigate the presence of ericoid mycorrhizal fungi in select peat and peat-based products. Vaccinium corymbosum, a known host of ericoid fungi, was used as a model plant. Peat and peat-based products were obtained from all major sources that supply the northeastern United States. Seedling roots were examined and average percent colonization was determined for each sample. Results indicate that these fungi are present in the majority of peat and peat-based media tested. Seedlings grown in some of the selected media exhibited an increased percentage of colonized root cells. Mycorrhizal fungi colonizing roots of test plants were isolated. These fungi exhibited typical ericoid fungal growth characteristics.
Karim H. Al-Juboory and David J. Williams
Shoot tip explants of Algerian Ivy Heder a canariensis were cultured on MS basal medium supplemented with a combination of salt strength and NAA and IBA. More roots per explant developed on full salt strength medium combined with NAA. The most roots per explant were obtained with a combination of IBA and 1/4 MS salt. There was an inverse relationship between an increase in IBA or NAA concentration and root length and number. Shoots proliferated better on full MS salt combined with NAA and IBA. The highest level of NAA (40 uM) and 0.1 uM TDZ produced the most shoots and roots, the longest roots, the highest rooting percentage, the largest plants with the most leaves and the best callus quality per explant. The leaves from in vitro were cultured on MS medium with varying levels of Thidiazuron (TDZ) and NAA in the presence of light produced the highest number of roots.