Watermelon (Citrullus vulgaris Schrad.) is a widely grown crop throughout the tropics and subtropics. In Mexico, it is an economically important crop. In vitro adventitious shoot regeneration of watermelon has been reported from shoot tip culture, leaf, hypocotyl, and cotyledons. Hence, the objective of this study was to evaluate in vitro plant regeneration from axillary buds of triploid watermelon. Axillary buds explants were prepared from shoot of commercial cultivar in field of 60 old day plants. Explants of 2 to 3 mm were incubated 2 weeks on Murashige and Skoog (MS) shoot regeneration medium containing 2.5 mg/L kinetin (KT) or indole-3-butyric acid (IBA), or gibberellic acid (GA3), followed by 3 weeks on shoot elongation medium supplemented with different combinations of the same phytohormones. The percentage of explants (83% to 90%) that produced shoots, expansion in size of explant (0.81–1 cm) and shoot length (6 mm) were highest in MS medium containing KT or IBA. In the shoot elongation step, shoot length (0.9–1 cm) and leaves number (6–7) were highest in MS medium supplemented with 2.5 mg/L of KT or GA3 and 0.2 mg/L IBA, but the better induction of roots in elongated shoot occurred on MS medium with 2.5 mg/L KT and 0.2 mg/L IBA. The results show that axillary buds from watermelon is an alternative for the micropropagation of this crop.
S. Guzman, H. Alejandro, J. Farias, A. Michel, and G. Lopez
M.W. George and R.R. Tripepi
Plant preservative mixture (PPM) is a new broad-spectrum biocide that may be useful for plant tissue culture. The objective of this study was to determine if PPM interfered with adventitious shoot regeneration on leaf explants from several plant species. Leaf explants from Dendranthema grandiflora `Iridon', Betula pendula, Rhododendron catawbiense var. album and R.c. `America' were made from the top two apical leaves on the microshoots. In the first experiment, 0, 0.5, 1, 2, or 4 mL·L-1 PPM were added to species-appropriate regeneration media. In the second experiment, only mum leaf explants were placed on regeneration media containing 0, 0.1, 0.2, 0.3, or 0.4 mL·L-1 PPM. The percentage of explants forming shoots and the number of shoots per regenerating explant were recorded after 4, 6, and 10 weeks, for mum, birch, and rhododendron leaves, respectively. The percentages of shoot regeneration from birch and rhododendron leaf explants were unaffected by up to 4 mL·L-1 PPM, and the number of shoots formed per R.c. album explant were also unaffected by the tested concentrations of PPM. In contrast, the numbers of shoots formed on birch and `America' explants were reduced 48% and 25%, respectively, when 4 mL·L-1 PPM was used in the media. The percentages of shoot regeneration and number of shoots per explant were drastically reduced on mum explants when only 0.5 mL·L-1 PPM was used in the medium. In fact, 0.3 mL·L-1 PPM or higher reduced shoot formation by more than 5-fold. This study demonstrates that the effects of PPM on shoot regeneration from leaf explants are species specific.
Mark H. Brand
To introduce desirable trait genes into Kalmia latifolia, efficient adventitious shoot regeneration methods are needed. Silver Dollar (S$) callus induction and growth in the dark was compared on Woody Plant (WP) medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) (1, 5, 10, 20 μM) or naphthaleneacetic acid (NAA) (1, 10, 20, 40 μM) with and without 5 μM isopentenyladenine (2iP). Both 2,4-D and NAA produced >450 mg of callus from leaf explants in 8 weeks. The addition of 2iP tripled growth for 2,4-D and doubled growth for NAA. Greatest callus growth was obtained on 20-40 μM NAA or 5-20 μM 2,4-D. Shoot regeneration on callus was achieved on WP medium containing 30 μM 2iP or 1 μM thidiazuron (TDZ), but a combination of the two was best, with 68% of dark-grown calli regenerating shoots in 4 weeks. 26% more dark-grown calli regenerated shoots than light-grown calli. The type of auxin (2,4-D or NAA) used to grow the calli did not affect shoot regeneration. For direct shoot regeneration, S$ leaf explants were tested on WP medium containing 5, 15, 30, 45 and 60 μM 2iP. The addition of 1 μM indole-3-butyric acid (IBA) doubled the percentage of leaves that regenerated shoots. 2iP concentrations between 15 and 45 μM supported excellent shoot regeneration, but optimal regeneration (95% of explants, 5.1 shoots/leaf) occurred on 30 μM 2iP+1 μM IBA. Leaf explants of six cultivars were grown on optimal medium with shoot regeneration ranging from 17% to 93% of leaves and 1.8 to 8.2 shoots per leaf, depending on the cultivar.
Areej A. Alosaimi, Robert R. Tripepi, and Stephen L. Love
reproduced by tissue culture. Most of these species have been micropropagated via adventitious shoot regeneration from excised seedling tissues (roots, stems, leaves, etc.), with the exception of L. repens and F. magellanica that can be reproduced by
Fatemeh Haddadi, Maheran Abd Aziz, Hossein Kamaladini, and Seyed Ali Ravanfar
157 Debnath, S.C. 2005 Strawberry sepal: Another explant for thidiazuron-induced adventitious shoot regeneration In Vitro Cell. Dev. Biol. Plant 41 671 676 Debnath, S.C. Teixeira da Silva, J.A. 2007 Strawberry culture in vitro: Applications in genetic
Qingrong Sun, Meijuan Sun, Hongyan Sun, Richard L. Bell, Linguang Li, Wei Zhang, and Jihan Tao
shoot formation from pear (Pyrus communis) leaf explants in vitro Plant Cell Tiss. Org. Cult. 27 315 319 Ancherani, M. Rosati, P. Predieri, S. 1990 Adventitious shoot regeneration formation from in vitro leaves of MM.106 apple clonal rootstock Acta
I-Ling Lai, Chih-Wan Lin, Tsai-Yu Chen, and Wei-Hsin Hu
vitro hybrid regeneration techniques should be investigated and the corresponding control mechanism determined before this hybrid is promoted for commercial use. Furthermore, light quality influences adventitious shoot regeneration ( Burritt and Leung
Nevena Mitić, Mariana Stanišić, Jelena Milojević, Ljiljana Tubić, Tatjana Ćosić, Radomirka Nikolić, Slavica Ninković, and Rade Miletić
in apple is the development of an efficient regeneration system that would increase adventitious shoot regeneration, because the regeneration ability of transformed tissues is much lower than that of non-transformed ones ( Pawlicki-Jullian et al
Dongliang Qiu, Xiangying Wei, Shufang Fan, Dawei Jian, and Jianjun Chen
that are equal to 1 cm. IBA = indole-3-butyric acid; WPM = woody plant medium; ZT = zeatin. Table 1. The number of adventitious shoots regenerated from leaf, stem, and callus explants of ‘Sunshine Blue’ cultured on woody plant medium supplemented with
Yi Tan, Baisha Li, Yi Wang, Ting Wu, Zhenhai Han, and Xinzhong Zhang
. 2012 Production of transgenic apple ( Malus domestica Borkh.) for improvement of fungal resistance Acta Hort. 961 195 203 Bell, R.L. Scorza, R. Lomberk, D. 2012 Adventitious shoot regeneration of pear ( Pyrus spp.) genotypes Plant Cell Tissue Organ