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
J.C. Vlahos, M. Dragassaki, and I. Assargiotaki
Achimenes is a summer-flowering pot plant commonly propagated by shoot tip cuttings taken from rhizomes released from dormancy. Micropropagation was used in this study in order to establish a protocol for producing plants in winter when Achimenes are not usually available. Leaf segments, taken in August 1993, from hybrids `Flamenco', `Rosenelfe', `Bella', and `Sandra' grown in a greenhouse, were cultured on a modified Murashige and Skoog (MS) medium supplemented with 0.1 mg·liter–1 BA and 0.5 mg·liter–1; shoots proliferated without callus formation. Leaf explants taken from the proliferated shoots were placed on MS medium with 0.5 mg·liter–1 BA and 0.1 mg·liter–1 NAA for 8 weeks for further shoots proliferation. `Bella' showed vigorous growth and produced the most shoots (82) with no rhizomes, whereas `Flamenco' had the least shoots (28) along with rhizomes. Shoot tips were then transferred on MS medium supplemented with 0.5 mg·liter–1 NAA for 6 weeks where more vigorous shoots developed along with roots. Microcuttings were directly stuck ex vitro under moisture and rooted well in 4 weeks before planting in individual culture and flowered normally. These results provide the basis for a successful production of Achimenes hybrids for growth and flowering in winter months provided optimal temperature and irradiance levels are given.
Michael Marcotrigiano and Susan P. McGlew
In an effort to accelerate breeding programs and to study somaclonal variation, a micropropagation system was devised for cranberries (Vaccinium macrocarpon). Using a factorial design, explants taken from greenhouse grown plants were placed on Anderson's medium containing different concentrations of 2ip' GA3, and IBA, with 4 cultivars tested over 3 subcultures. In other experiments, explant source, macro and micro salt formulations, and rooting treatments, were studied. Optimal multiplication and shoot quality occurred when single node explants taken from greenhouse grown plants were placed on Anderson's media containing 150 uM 2iP, 1.0 uM IBA and no GA3. Histological examinations indicate that initial response is axillary bud proliferation but upon subculture adventitious shoot formation may be possible. Proliferated shoots could be rooted ex vitro in plug trays under plastic tents and without hormone treatments. Optimal rooting occurred under high light conditions in a 1:1 (v:v) peat:sand mix. Plants were easily transplanted into the field in spring and will be evaluated by comparison to conventionally propagated material.
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