species is necessary. In this study, we describe a reliable and reproducible method to propagate I. dumosa through in vitro culture of cut pyrenes. Materials and Methods Plant material. Open-pollinated ripe drupes of I. dumosa ( Fig. 1A ) were
Natalia R. Dolce, Luis A. Mroginski, and Hebe Y. Rey
Juan Bernardo Pérez-Hernández and María José Grajal-Martín
less than 1% ( Usman et al., 2001 ); and 3) severe natural fruit drop that causes premature loss of many of the scarce fruits derived from putative successful hand crosses ( Bally et al., 2009 ). Therefore, in vitro culture of immature embryos has been
Hua Q. Zhao, Qing H. He, Li L. Song, Mei F. Hou, and Zhi G. Zhang
acclimatization in greenhouse. The protocol established in this investigation will facilitate future mass propagation of H. villosa ‘Caramel’. Literature Cited Barakat, M.N. El-Sammak, H. 2011 In vitro culture and plant regeneration from shoot tip and lateral
Guochen Yang and Marihelen Kamp-Glass
Exochorda racemosa is an ornamental shrub with white flowers that is spiraea-like, deciduous, and hardy. The buds resemble pearls. Normally it is propagated by seeds, layers, and cuttings of softwood. However, it is a slow process that takes a few years to produce a reasonable size plant for the demanding market. Our objective was to establish a successful in vitro culture and to rapidly multiply this ornamental species. Softwood explant materials were collected from a local nursery and were disinfested with 15% bleach solution and rinsed three times with sterile distilled and deionized water. In vitro cultures were established and maintained in woody plant medium (WPM) supplemented with BA at 0.1 mg·L-1, 3% sucrose, and 0.7% agar with the pH adjusted to 5.8. Then shoots were transferred to the multiplication medium containing BA, CPPU, or thidiazuron (TDZ) at various concentrations. Preliminary results show that explants cultured on medium containing TDZ produced the best shoot proliferation.
Farida Safadi, Harrison Hughes, and Giuseppe Zerbi
Research involving acclimatization of in vitro plantlets by reducing the relative humidity (RH) in vitro requires a suitable method for monitoring RH in the culture vessels. In this research we describe a method for measuring the RH dynamically in the culture vessels, based upon thermocouple psychrometry. Thermocouple junctions (.003 mm gauge) were used with a wet cotton thread on the wet bulb junction inserted from the side of the jar. Aspiration was provided by tiny fans run by miniature motors left outside the vessels. Pre-calibrated aspirated and non-aspirated experiments showed realistically reduced RH in the cultures covered with caps which allowed for gas exchange. The aspirated procedure resulted in greater precision. This procedure with some refinement could be a useful method for monitoring RH in in vitro cultures.
Arancha Arbeloa, Ma Elena Daorden, Elena García, Pilar Andreu, and Juan A. Marín
of ovule culture in breeding programs, primarily for early-maturing peaches and nectarines ( Emershad and Ramming, 1994 ; Pinto et al., 1994 ; Ramming, 1985 ; Ramming et al., 2003 ; Sinclair and Byrne, 2003 ). In addition, in vitro culturing of
Kaitlin J. Palla, Rochelle R. Beasley, and Paula M. Pijut
of common persimmon and one hybrid genotype. To the best of our knowledge this is the first report on in vitro culture of these cultivars of common persimmon and this hybrid. Fig. 1. Growth habit and fall color ( A ), fruit ( B ), and quarter-cut wood
Chockpisit Channuntapipat, Margaret Sedgley, and Graham Collins
Leaf explants were taken from mature leaves of two almond [Prunus dulcis (Miller) D.A. Webb] cultivars, Ne Plus Ultra and Nonpareil selection 15-1, and maintained in vitro to grow shoot tips. Shoot tips were grown also from a pre-existing in vitro culture of an almond-peach rootstock, P. dulcis `Titan' × P. persica `Nemaguard'. The shoot tips were harvested, cryopreserved, and tested for survival after 3 days and then at intervals of 3 months up to two years. The mean survival was 80% for `Ne Plus Ultra', 54% for `Nonpareil', and 78% for the hybrid rootstock, and there were no significant differences in survival between 3 days and 24 months. The effects of in vitro culture and cryopreservation on DNA integrity were examined by both RAPD-PCR, and restriction enzyme digestion followed by RAPD-PCR, using DNA from the original trees from which the explants were derived, from leaves regrown from cultures that had undergone several passages of in vitro culture, and from leaves regrown from cryopreserved shoot tips. No detectable differences were found between the DNA fingerprints of each DNA sample using RAPD-PCR with seven different 10-mer primers. However, differences were detected when the DNA was first digested with the isoschizomeric pairs, Hpa II/Msp I and Bsp 143 I/Mbo I and then subjected to RAPD-PCR with six different 10-mer primers. Changes in the structure and methylation of DNA were found that were probably related to the process of in vitro culture, and in addition, methylation changes were detected that were probably associated with the cryopreservation process. These changes did not appear to be caused by the vitrification solution used before immersion of shoot tips in liquid nitrogen. While cryopreservation appears to be an ideal method for the long-term storage of almond germplasm, the significance of the alterations to both methylation and structure of DNA needs to monitored in regenerated plants, especially as they relate to agronomic performance when the regenerants become reproductively mature.
Guillermo Pratta, Lilians N. Cánepa, Roxana Zorzoli, and Liliana A. Picardi
Estimates of genetic variability for in vitro culture traits among the genus Lycopersicon and evaluation of the gene effects involved in callus production and shoot formation were achieved. Five parents including wild and cultivated tomato genotypes and their nonreciprocal 10 possible hybrid combinations were assayed. The callus percentage (C = number of cultures that only produced callus× 100/total number of cultures), the regeneration percentage (R = number of cultures that differentiated into shoots or primordia × 100/total number of cultures) and the productivity rate (PR = total number of shoots/total number of cultures) of each genotype were calculated 45 days after culture initiation. Diallel analysis revealed genetic variability for in vitro culture response. Wild genotypes contributed to a reduction in callus production and an increase in shoot formation while the cultivated genotypes either had an opposite effect or did not modify the expression of culture traits. Hybrids had the lowest callus production and highest shoot formation percentage. Additive gene effects were mainly involved in the expression of C and R, while both additive and nonadditive gene effects were involved in expression of PR.
Antonio Figueira and Jules Janick
In vitro culture of axillary cotyledonary shoots of Theobroma cacao L. (cacao) under increasing CO2 concentration from ambient to 24,000 ppm (culture tube levels) significantly increased total shoot elongation, number of leaves, leaf area per explant, and shoot dry and fresh weight. Although light was necessary for the CO2 response, the effect of various photon fluxes was not significant for the measured growth parameters. Net photosynthesis estimated on the basis of CO2 depletion in culture tubes increased 3.5 times from 463 to 2639 ppm CO2, and increased 1.5 times from 2639 to 14,849 ppm CO2, but declined from 14,849 to 24,015 ppm CO2. Ethylene concentration in culture vessels increased under enriched CO2 conditions. Depletion of nutrients (fructose, K, Ca, Mg, and P) from the medium was increased under enriched CO2 conditions.