significance was determined at 5% using the SPSS 20.0 program (IBM Corporation, Armonk, NY). Results Adventitious shoot regeneration. To evaluate the effects of exogenous hormones on adventitious shoot regeneration, 10 regeneration media (WPRM1–WPRM10) were
Xiaojuan Zong, Brandon J. Denler, Gharbia H. Danial, Yongjian Chang, and Guo-qing Song
Takahiro Tezuka, Masashi Harada, Masahumi Johkan, Satoshi Yamasaki, Hideyuki Tanaka, and Masayuki Oda
). This method enables in vivo adventitious shoot regeneration from stumps after decapitation of the primary shoot and all lateral branches. Harada et al. (2005) reported that 79 shoots were regenerated from the cut surface of primary shoots and lateral
Charleson R Poovaiah, Stephen C Weller, and Matthew A Jenks
An in vitro shoot regeneration procedure was developed for native spearmint (Mentha spicata L.) using internodal explants. Shoot regeneration from internodes was evaluated on Murashige and Skoog (MS) media supplemented with individual cytokinins thidiazuron (TDZ), benzylaminopurine (BA), kinetin (KT), or zeatin (ZT) or various pair wise combinations of these. The highest regeneration was achieved by the second internode on a medium containing MS basal salts, B5 vitamins, 10% coconut water, 1.0 mg·L–1 TDZ, 2.5 mg·L–1 ZT, and solidified with 0.2% phytagel. Unlike previous protocols this medium does not need sub culturing and produces elongated shoots in 4 weeks, rather than 6 weeks. Maximum number of shoots (36 per explant after 4 weeks) was observed when internodes from 2-week-old stock plants were used as explant source. The shoots were removed and roots were initiated on medium containing MS basal salts, 0.4 mg·L–1 thiamine-HCL, 100 mg·L–1 myo-inositol, 7.5 g·L–1 agar and 0.01 mg·L–1 ∝-napthaleneacetic acid (NAA) and then plants were transferred to the greenhouse 2 weeks after root initiation, where 100% of the plantlets developed into healthy plants.
James F. Harbage and Dennis P. Stimart
Callus culture establishment and adventitious shoot development from callus of Rhododendron × ‘Gibraltar’ (G) and R. × ‘Old Gold’ (OG) after serial subculture were determined. Callus grew on Anderson's Rhododendron medium containing 2,4- D at 0.0045, 0.009, or 0.018 mm, but was optimum at 0.018 mm, since shoot organogenesis was suppressed at that level. After two callus subcultures, adventitious shoot development from callus on media containing 0, 0.017, 0.034, 0.068, or 0.136 mm zeatin (mixed isomers) was optimum at 0.034 and 0.068 mm zeatin for G and OG, respectively. After 17 weeks (five subcultures), 70- to 75-mg pieces of G and OG callus regenerated ≈20 shoots each. Adventitious shoot regeneration from callus declined with prolonged callus subculture. Regenerated plants are currently being evaluated for somaclonal variation. Chemical names used: (2,4-dichlorophenoxy)acetic acid (2,4-D); (E)-2-methyl-4-(1H-purin-6-ylamino)-2-buren-1-ol (zeatin).
L. Xu, G.F. Liu, and M.Z. Bao
(photosynthetic photon flux) provided by 40-W cool-white fluorescent tubes. The expanding leaves (8 mm in length) were used for adventitious shoot regeneration. Shoot regeneration. P6 was used in the primary experiment. Expanded leaves were wounded by
Samir C. Debnath
The effects of TDZ (0, 0.1, 1, 5 and 10 μm) and explant orientation on adventitious shoot regeneration of `Erntedank' lingonberry were studied. Moderate concentration (1 to 5 μm) of TDZ supported bud and shoot regeneration, but strongly inhibited shoot elongation. TDZ initiated cultures were transferred to medium containing 1-2 μm zeatin and produced usable shoots after one additional subculture. Adventitious bud and shoot regeneration was greatly influenced by explant orientation. Elongated shoots were rooted on a 2 peat: 1 perlite (v/v) medium, and the plantlets were acclimatized and eventually established in the greenhouse with 80% to 90% survival rate.
Mohsen Hesami and Mohammad Hosein Daneshvar
organogenesis method via adventitious shoot regeneration are not sufficient for conservation purposes. To conserve these ornamental and medicinal plants, it is necessary to establish multiple plant organogenesis pathways. In addition, indirect organogenesis is
E.R.M. Wickremesinhe, W.J. Blackmon, and B.D. Reynolds
Shoots were regenerated from callus of Apios americana Medikus (apios, groundnut) using internodal explants from in vitro-germinated seedlings and from sprouted tubers on a modified Murashige and Skoog (MS) basal medium. Shoot regeneration was observed over a range of 2iP and IBA combinations. GA3 increased the number of shoots regenerated per epicotyl explant. The most efficient regeneration (≈90%) was with internodal epicotyl explants on 100 μm 2iP, 0.5 μm IBA, and 1.5 μm GA3. Regenerated shoots were rooted on liquid and solid MS medium with 0.5 μm IBA; however, rooting was more successful on the liquid medium. About 60% of rooted plants were successfully established in pots. Chemical names used: N-(3-methyl2-butenyl)-1 H-purin-6-amine (2iP), 1 H-indole-3-butanoic acid (IBA), gibberellic acid (G A3).
Ana Carolina Espinosa, Paula M. Pijut, and Charles H. Michler
A complete regeneration protocol was developed for Prunus serotina Ehrh., an important hardwood species for timber and sawlog production in the central and eastern United States. Nodal sections were cultured on Murashige and Skoog (MS) medium supplemented with 4.44 μm 6-benzylaminopurine (BA), 0.49 μm indole-3-butyric acid (IBA), and 0.29 μm gibberellic acid (GA3). In vitro leaf explants of three genotypes were placed on woody plant medium (WPM) supplemented with 0, 2.27, 4.54, or 6.81 μm thidiazuron (TDZ) in combination with 0, 0.54, 1.07, or 5.37 μm naphthaleneacetic acid (NAA), and on WPM supplemented with 0, 4.44, 8.88, or 13.32 μm BA in combination with 0, 0.54, 1.07, or 5.37 μm NAA. Cultures were maintained either in continuous darkness for 5 weeks, or in the dark for 3 weeks and then transferred to a 16-hour photoperiod. TDZ and the genotype had a significant effect on the number of shoots regenerated. The maximum mean number of shoots regenerated per explant (5.05 ± 1.14) was obtained with 2.27 μm TDZ plus 0.54 μm NAA with the 3-week dark period then light treatment. The highest percent shoot regeneration (38.3) and mean number of shoots (4.13 ± 0.97) was obtained with 6.81 μm TDZ plus 1.07 μm NAA. The highest rooting (27%) of adventitious shoots and number of roots per shoot (2.3 ± 0.2) was obtained with 2.5 μm IBA when shoots were maintained for 7 days in the dark on rooting medium before transfer to a 16-hour photoperiod. The highest rooting (70%) of nodal explant-derived stock cultures and number of roots per shoot (2.7 ± 0.9) was also obtained with 2.5 μm IBA, but when shoots were maintained for 4 days in the dark before transfer to a 16-hour photoperiod. In total, 86% of the plantlets survived acclimatization to the greenhouse and 100% survival after overwintering in cold-storage.
Fabiola Domínguez, Xavier Lozoya, and James Simon
An efficient whole plant regeneration method from callus cultures of Piper auritum was achieved through organogenesis derived from leaf tissue. Proliferating callus and shoot cultures derived from leaf tissue explants placed on Murashige and Skoog (MS) medium supplemented with 2.0 mg·L–1 2, 4-dichlorophenoxyacetic acid (2,4-D) plus 1.5 mg·L–1 kinetin. Optimum combination of hormones (mg·L–1) for shoot induction was 0.5 2,4-D: 1.5 mg·L–1 kinetin (by volume), that resulted in a high rooting rate (49.6 shoots per explant). All of the plants elongated when using a medium consisting of 0.1 mg·L–1 2,4-D plus 1 mg·L–1 kinetin. Elongated shoots were successfully rooted (100%) on half-strength MS medium supplemented with 2.0 mg·L–1 indole-3-acetic acid. All plantlets survived to the growing conditions of a greenhouse. This study demonstrates that leaf tissue of P. auritum is competent for adventitious shoot regeneration and establishes an efficient and useful protocol for the multiplication and conservation of P. autirum for further investigation of its medicinally active constituents.