During freezing studies of `Concord' grape (Vitis labrusca L.), bud viability significantly affected callus formation, adventitious root initiation, and root dry weight during regrowth assays conducted to assess freezing injury. Applying exogenous 1- H -indole-3-acetic acid (IAA) partially offset bud loss and stimulated root initiation. Further tests demonstrated that buds were less cold hardy than internode woody tissues in dormant `Concord' canes. Because of cold-hardiness differences between buds and wood and because bud viability affects callus formation, root initiation, and root dry weight, regrowth assays do not seem to be sensitive indicators of freezing injury in grape woody tissues. Regrowth assays, however, seem to be reliable indicators of overall viability for frozen `Concord' grape cuttings.
Danny L. Barney
Danny L. Barney
Seeds of V. membranaceum germinated in petri dishes fresh (undried), airdried for 7 days, or cold-stored for 1 or 6 years exhibited similar germination vs. time curves. Dry storage at 0–4°C for 1 or 6 years did not reduce the percentage of germination compared to fresh seeds. Cold stratification at 0–4°C slowed germination by extending the initial lag phase compared to unstratified seed. Stratification for 28 to 56 days delayed germination by ≈2 weeks. This pattern held true for fresh (undried) seed, seed air-dried for 7 days, and seed cold-stored for 6 years. Surface sterilization for 20 or 30 minutes with a 0.5% aqueous solution of sodium hypochlorite reduced fungal and bacterial contamination of germinating seeds without adversely impacting germination. Treatment of V. membranaceum seeds with captan or mancozeb fungicide inhibited germination by extending the lag phase and reducing the germination vs. time slope of the exponential phase. Mancozeb-treated seeds exhibited a lower percentage of germination than did controls, and often developed necrotic radical tips.
Danny L. Barney
During the 1800s and early 1900s, red and white currants (Ribes L. subgenus Ribes), black currants (Ribes subgenus Coreosma), and gooseberries (Ribes subgenus Grossularia) were grown commercially in the United States. Because Ribes serve as alternative hosts of white pine blister rust (Cronartium ribicola J. C. Fischer) (WPBR), which was introduced from Europe, the federal government and many states either banned or severely restricted currant and gooseberry production beginning about 1933. The development of WPBR resistant pines and black currants (the most susceptible cultivated Ribes) renewed interest in commercial Ribes production. Climatic and soil conditions in selected areas of the U.S. inland northwest and intermountain west (INIW) are favorable for commercial currant and gooseberry production. Challenges to the establishment of a Ribes industry are labor, marketing, diseases, and pests. Careful site and cultivar selection are critical for successful commercial production. This article describes Ribes opportunities and risks associated with currant and gooseberry production in the INIW. The region includes Idaho and surrounding areas in Montana, Nevada, Oregon, Utah, Washington, and Wyoming.
Bahman Shafii and Danny L. Barney
Trials were conducted to determine the effects of air drying and cold storage on black huckleberry (Vaccinium membranaceum Douglas ex Hooker) seeds. Treatments included fresh seeds, seeds air-dried for 7 days, and those air-dried and stored at 2 to 3 °C for either 1 or 7 years. Germination was measured every 7 days. The time course of germination was modeled using a logistic growth curve from which days to 50% germination (T50), germination rate index, and maximum germination percentages were estimated. Germination curves of dried and of dried and cold-stored seeds were significantly different from that of fresh seeds. Seeds stored for 1 or 7 years had germination percentages similar to those for the fresh, nondried seeds. Air drying for 7 days reduced the maximum germination percentage from 73% to 59% (fresh seeds). This induced dormancy was gradually lost during cold storage of dry seeds. Cold storage of air-dried seeds was an effective method for preserving V. membranaceum germplasm for at least 7 years.
Samir C. Debnath and Danny L. Barney
A plant regeneration protocol was developed for cascade huckleberry (Vaccinium deliciosum), mountain huckleberry (V. membranaceum), and oval-leaf bilberry (V. ovalifolium) clones. The effects of zeatin concentrations (0, 4.6, 9.1, and 13.7 μM) and explant type (leaf or stem segment) on adventitious shoot regeneration were studied on a nutrient medium of low ionic concentration. Adventitious bud and shoot regeneration was greatly influenced by clone, explant type, and zeatin concentration. Zeatin at 9.1 to 13.7 μM supported the best bud and shoot regeneration. At low concentrations (2.3 to 4.6 μM), zeatin enhanced shoot elongation and produced usable shoots after one additional subculture. The three clones differed significantly with respect to multiplication rate of adventitious shoots. Oval-leaf bilberry and mountain huckleberry clones produced six to seven 5-cm-long shoots per explant and cascade huckleberry clone produced five 3-cm-long shoots per explant, when 2.3 μM zeatin was used in the medium. Increasing the concentration of zeatin in the culture medium increased shoot number per explant, but decreased shoot height, leaf number per shoot, and shoot vigor. Proliferated shoots were rooted on the same medium but without any plant growth regulators (PGRs). Rooted plantlets were transferred to a 2 peat:1 perlite (v/v) medium for acclimatization and eventually established in the greenhouse with 75% to 90% survival rate. This in vitro protocol will be useful for micropropagation, in vitro selection, and genetic manipulation of Vaccinium species.
Kim E. Hummer and Danny L. Barney
Danny L. Barney, Michael Bauer, and Jennifer Jensen
Trees from six corkbark fir (Abies lasiocarpa var. arizonica) and 10 subalpine fir (A. lasiocarpa var. lasiocarpa) seed sources were grown at the University of Idaho Sandpoint Research and Extension Center (SREC), Sandpoint, ID, and two commercial nurseries in Idaho and Oregon. Posttransplant mortality was highest during the first two years. After six growing seasons, survival averaged 76% and 80% for corkbark and subalpine fir, respectively. In SREC irrigated plots, survival averaged 96% and 99% for corkbark and subalpine fir, respectively. Spring frost damage occurred annually on 66% to 100% of trees during 2002–06. In SREC plots, damage was minor and did not adversely affect appearance. Tree heights and growth rates varied significantly between seed sources. In general, corkbark fir grew faster than subalpine fir. After nine years in the field, mean heights of SREC-grown corkbark trees ranged from 2.1 to 2.9 m and that of subalpine trees ranged from 1.3 to 2.3 m, depending on seed source. Corkbark fir proved moderately resistant to resistant to a phoma-type fungal blight. Three corkbark seed sources appeared suitable for Christmas tree production. Subalpine trees were more susceptible to the blight. Some trees within both botanical varieties proved resistant to or highly tolerant of the blight, but the use of seedlings for landscapes may be unacceptably risky because of disease potential. Two fungicide programs (three applications of pyraclostrobin plus boscalid or one application of pyraclostrobin plus boscalid followed by one application of chlorothalonil) controlled the blight. Eight subalpine fir and 23 corkbark fir at SREC were selected for further testing as possible cultivars. Neither crop is recommended for sites with frequent or severe spring frosts.
Danny L. Barney, Omar A. Lopez, and Elizabeth King
Two concentrations of two in vitro media formulations were evaluated for their effects on survival, shoot growth, and percentage rooting of cascade huckleberry (Vaccinium deliciosum), mountain huckleberry (V. membranaceum), and oval-leaf bilberry (V. ovalifolium). Two-node stem sections from established microshoots were cultured on full- or half-strength modified Murashige and Skoog medium (FSMS and HSMS) or full- or half-strength modified woody plant medium (FSWPM and HSWPM) unamended with plant growth regulators. Cultures were maintained at 21 °C with a 16-hour photoperiod for 98 days. Survival on FSMS was reduced by ≈44% for cascade huckleberry, 63% for mountain huckleberry, and 18% for oval-leaf bilberry compared with average survival on HSMS, HSWPM, and FSWPM. Explants on FSMS also produced new shoot growth having the lowest dry weights, fewest shoots, and shortest shoots of the four media. Explant rooting percentages were also least on FSMS. For cascade huckleberry and oval-leaf bilberry, HSMS, HSWPM, and FSWPM all appeared suitable for general culture. For mountain huckleberry, both woody plant medium formulations produced greater microshoot dry weights, average shoot lengths, and explant rooting percentages compared with HSMS. These results are the first published on micropropagation for cascade huckleberry and oval-leaf bilberry, and provide starting protocols for commercial propagation and further research on micropropagation of these species.