Butternut (Juglans cinerea L.), a native hardwood to the northeastern United States, is a valuable species for its wood and edible nuts. Butternut is becoming endangered in its native range as a result of a virulent fungal (perennial canker) pathogen, Sirococcus clavigignenti - juglandacearum. Micropropagation techniques are being developed to clone disease-resistant specimens. Axillary buds, obtained from 2-3-month old seedlings, were induced to break buds in vitro and form a single shoot when cultured on Murashige and Skoog (MS) medium supplemented with 200 mg/l casein hydrolysate, 3% sucrose, and 2 mg/l 6-benzylaminopurine. Roots were initiated on microshoots when cultured on half-strength MS medium containing 100 mg/l casein hydrolysate, 1.5% sucrose, and 0.5 mg/l indole-3-butyric acid for seven days in the dark. Adventitious roots elongated when shoots were placed in the light on the same medium, but with 2% sucrose, and no growth regulators. Rooted plantlets were successfully acclimated ex vitro. These results provide a basis for the development of techniques to micropropagate selected, mature, disease-resistant butternut germ plasm.
Paula M. Pijut
Michael Marcotrigiano and Susan P. McGlew
A two-stage micropropagation system was devised for cranberries (Vaccinium macrocarpon Ait.). Shoot-tip explants taken from four cultivars of greenhouse-grown plants were placed on media composed of Anderson's major salts, Murashige and Skoog's (MS) minor salts and organics, plus various concentrations of 2iP, IBA, and GA3. In other experiments, explant source, salt formulations for media, and rooting treatments were studied. Optimal multiplication and shoot quality occurred when nodal explants taken from greenhouse-grown or micropropagated plants were placed on medium containing 150 μm 2iP, 1.0 μm IBA, and no GA3. Histological examination revealed that the initial response of nodes to culture is axillary bud proliferation, but adventitious shoot formation occurred after 4 to 6 weeks. Cultures that contained only axillary shoots were not evident unless low levels of 2iP were used, at which point only axillary buds present on the explants were released. Proliferated shoots could be rooted ex vitro without auxin treatment. Optimal rooting occurred under high-light conditions. Plants were transplanted to the field for comparison to conventionally propagated material. Chemical names used: gibberellic acid (GA3), N-(3-methyl-2-butenyl)-1H-purin-6-amine (2iP), 1H-indole-3-butanoic acid (IBA).
Mónica Moura, Maria Irene Candeias, and Luís Silva
process. Micropropagation has great potential for the protection of endangered endemic taxa ( Bramwell, 1990 ; Osorio-Rosales and Mata-Rosas, 2005 ) by allowing genotype maintenance and resolution of problems related to self-incompatibility, fertility
Michael E. Compton, Brenda L. Fuchs, and Jack E. Staub
Cucumis hystrix Chakr. is a rare cucurbit species native to Asia. The species is valued by breeders because of its multiple branching habit and has been used in interspecific crosses with Cucumis sativus. However, individual C. hystrix plants have not been identified in the wild since 1990. Therefore, it was our objective to develop a micropropagation protocol that would allow us to clonally propagate plants in cultivation. Shoots tips (2 cm) were excised from a single C. hystrix plant grown in the greenhouse. All tendrils and leaves were removed before surface-sterilization in 1.25% NaOCl for 5 or 10 min and rinsed six times with sterile distilled water. Shoot tips were trimmed to 1 cm (meristem with two to three young leaf primordia) and placed into 25 × 125-mm test tubes containing 25 ml of initiation medium [MS plus (per liter) 100 mg inositol, 30 g sucrose and 5 g Agargel; pH 5.7-5.8]. PGR combinations tested were initiation medium with 1 μM BA, and initiation medium with 1.7 μM IBA, 0.5 μM kinetin and 0.3 μM GA3 (IKG). Explant survival was greater when shoot tips were surface-sterilized for 5 min (75%) compared to 10 min (33%). More axillary shoots formed when shoot tips were cultured in IKG medium (10.8) than in medium with BA (5.5). Shoots were considerably longer (10 mm) when cultured in medium with IKG compared to BA (1.5 mm). About 64% of shoots place in medium containing 8 μM NAA formed roots and were acclimatized to greenhouse conditions.
Fatemeh Haddadi, Maheran Abd Aziz, Ghizan Saleh, Azmi Abd Rashid, and Hossein Kamaladini
, Malaysia. The availability of an efficient micropropagation protocol for ‘Camarosa’ strawberry developed in this study may assist in overcoming the shortage of runners as planting materials often faced by farmers in Cameron Highlands. Materials and
Ilse-Yazmín Arciniega-Carreón, Carmen Oliver-Salvador, María-Guadalupe Ramírez-Sotelo, and Carlos Edmundo Salas
of seasonal factors. A standardized protocol for in vitro micropropagation represents a suitable option for the conservation of endangered species or propagation of variants with a desired phenotype ( Elias et al., 2015 ). Many of these protocols have
Inmaculada Vila, Ester Sales, Javier Ollero, Jesús Muñoz-Bertomeu, Juan Segura, and Isabel Arrillaga
wastewater purification and for restoration of riparian woodlands ( Adrover et al., 2008 ). Besides the interest of oleander micropropagation for commercial-scale plant production, adventitious regeneration would allow the genetic engineering of this plant
Beatrice Nesi, Debora Trinchello, Sara Lazzereschi, Antonio Grassotti, and Barbara Ruffoni
-free plants must be developed to produce quality plants and avoid developmental abnormalities. Micropropagation protocols in vitro have been developed to produce virus-free lily propagules ( Spiegel, 2006 ). In many lilies, lily symptomless virus (LSV) has
Loren D. Gautz and Charles W. Wong
A device is described that can be used to open and close Magenta vessels used for micropropagation. Performance of the device is reported and compared favorably to unassisted manual opening and closing of vessels. Benefits include elimination of a potentially physically damaging (e.g., carpal tunnel syndrome) manual operation.
Piyada A. Tantasawat, Apinya Khairum, Kitiya Arsakit, Oythip Poolsawat, Paniti Pornbungkerd, and Chitpan Kativat
.g., division of clumps, cutting, separating of offshoots, and micropropagation). At present, micropropagation is often used commercially because it allows multiplication in large quantities ( Puchooa, 2004 ). Dendrobium can be micropropagated via protocorms