scholarly journals Vegetative Propagation of Phytophthora cinnamomi-Tolerant Holm Oak Genotypes by Axillary Budding and Somatic Embryogenesis

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 841
Author(s):  
Maria Teresa Martínez ◽  
Francisco Javier Vieitez ◽  
Alejandro Solla ◽  
Raúl Tapias ◽  
Noelia Ramírez-Martín ◽  
...  

Holm oak (Quercus ilex) is one of the most widely distributed tree species in the Mediterranean basin. High mortality rates have been observed in holm oak populations in the southwest of the Iberian Peninsula as a result of oak decline syndrome. Selection and propagation of genotypes tolerant to this syndrome could aid the restoration of affected areas. In this article, we report micropropagation and conservation procedures based on axillary budding and somatic embryogenesis (SE) of holm oak plants, selected for their tolerance to Phytophthora cinnamomi—the main biotic factor responsible for oak decline. Forced shoots were obtained from potted plants of eight different genotypes, and used as stock material to establish in vitro shoot proliferation cultures. Reliable shoot proliferation was obtained in seven out the eight genotypes established in vitro, whereas multiplication rates were genotype-dependent. The highest rooting rates were obtained by culturing shoots for 24 h or 48 h on rooting induction medium containing 25 mg L−1 indole-3-butyric acid, followed by transfer to medium supplemented with 20 µM silver thiosulphate. Axillary shoot cultures can be successful conserved by cold storage for 12 months at 4 °C under dim lighting. Shoot tips, excised from axillary shoot cultures established from tolerant plants, were used as initial explants to induce SE. Somatic embryos and/or nodular embryogenic structures were obtained on induction medium with or without indole-acetic acid 4 mg L−1, in two out the three genotypes evaluated, and induction rates ranged between 2 and 4%. Plantlet recovery was 45% after two months cold stratification of somatic embryos and eight weeks of culture on germination medium. Vegetative propagation of P. cinnamomi-tolerant Q. ilex trees is a valuable milestone towards the restoration of disease-affected areas.

2012 ◽  
Vol 49 (No. 12) ◽  
pp. 537-543 ◽  
Author(s):  
V. Chalupa

In vitro propagation of Tilia platyphyllos Scop. has been achieved by axillary shoot proliferation and somatic embryo-<br />genesis. The influence of tree age, explant source, genotype, and phytohormones on micropropagation of juvenile and mature trees of Tilia platyphyllos has been investigated. Nodal segments and shoot tips were used as initial explants for axillary shoot proliferation. Low concentration of cytokinin (BA, BPA, TDZ) plus auxin (IBA) stimulated fast shoot multiplication. Microshoots<br />excised from proliferating cultures were rooted on low salt medium and produced trees were planted in the field. Embryo-<br />genic tissues were initiated from zygotic embryos cultured on MS medium supplemented with 2,4-D. After transfer of&nbsp; embryogenic tissues with developing embryoids on media lacking 2,4-D and supplemented with low concetration of IBA, the development of somatic embryos was enhanced. Secondary somatic embryogenesis led to the formation of new adventive somatic embryos. Trees produced from somatic embryos were planted in the field and exhibited normal growth and morphology.


Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 712
Author(s):  
Marzena Nowakowska ◽  
Žaklina Pavlović ◽  
Marcin Nowicki ◽  
Sarah L. Boggess ◽  
Robert N. Trigiano

Helianthus verticillatus (Asteraceae), whorled sunflower, is a perennial species restricted to a few locations in the Southeastern United States. Habitat loss has caused H. verticillatus to become rare, and since 2014, it has been federally listed as an endangered species. As a part of the recovery plan for the restoration and protection of H. verticillatus, an efficient micropropagation protocol based on axillary shoot proliferation was developed. Various concentrations of 6-benzylaminopurine (BAP; 0 to 4.44 µM) were examined for their morphogenetic potential in the regeneration of six genotypes of H. verticillatus from the nodal explants derived from greenhouse-grown plants. Both the BAP concentration and genotype had significant effects on the regeneration capacity of H. verticillatus. Although the induced buds were observed on ½-strength Murashige and Skoog medium without plant growth regulators, a higher rate of induction and bud development were achieved on media with either 0.88 or 2.22 µM BAP, regardless of the genotype. Successful rooting of the induced shoots was achieved within four weeks after the transfer from the induction medium to the fresh ½-strength MS medium, but the rooting efficiency was dependent on the plant’s genetic background. Regenerated plantlets, with well-developed shoots and roots, were acclimatized successfully to greenhouse conditions with a 97% survival rate. Simple sequence repeats (SSRs) markers were employed to assess the genetic uniformity of the micropropagated plants of H. verticillatus. No extraneous bands were detected between regenerants and their respective donor plants, confirming the genetic fidelity and stability of regenerated plants. To our knowledge, the protocol developed in this study is the first such report for this endangered species.


Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1634
Author(s):  
Mª Teresa Martínez ◽  
Isabel Arrillaga ◽  
Ester Sales ◽  
María Amparo Pérez-Oliver ◽  
Mª del Carmen González-Mas ◽  
...  

Holm oak populations have deteriorated drastically due to oak decline syndrome. The first objective of the present study was to investigate the use of axillary budding and somatic embryogenesis (SE) to propagate asymptomatic holm oak genotypes identified in disease hotspots in Spain. Axillary budding was achieved in two out of six tolerant genotypes from the south-western region and in two out of four genotypes from the Mediterranean region. Rooting of shoots cultured on medium supplemented with 3 mg L−1 of indole-3-acetic acid plus 0.1 mg L−1 α-naphthalene acetic acid was achieved, with rates ranging from 8 to 36%. Shoot cultures remained viable after cold storage for 9–12 months; this procedure is therefore suitable for medium-term conservation of holm oak germplasm. SE was induced in two out of the three genotypes tested, by using nodes and shoot tips cultured in medium without plant growth regulators. In vitro cloned progenies of the tolerant genotypes PL-T2 and VA5 inhibited growth of Phytophthora cinnamomi mycelia when exposed to the oomycete in vitro. Significant differences in total phenol contents and in the expression profiles of genes regulating phenylpropanoid biosynthesis were observed between in vitro cultured shoots derived from tolerant trees and cultures established from control genotypes.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 783E-783
Author(s):  
S.K. Dhir ◽  
U.L. Yadava

An efficient protocol has been developed for the in vitro multiplication of papaya (Carica papaya L.) through somatic embryogenesis utilizing immature zgotic embryos. Somatic embryos were initiated on MS basel media supplemented with 5 mg·liter–1 2,4-D, 400 mg·liter–1 glutamine, and 6% sucrose. After culturing for 2 months, 65% of the explants became highly embryogenic. Each explant produced 50 to 80 embryos in 4 months on culture induction medium. Frequency of embryogenesis was increased (75 to 150 somatic embryos on 80% explants) upon supplementing medium with 4% maltose as a carbon source and 100 mg·liter–1 L-asparagine. The embryogenic callus appeared yellow and embryos at different stages of development were well-organized. On regular subculturing, these cultures continued to produce secondary embryos. Following their transfer to the hormone-free medium supplemented with 4% maltose, these embryos germinated. The somatic embryogenesis system is rapid, repetitive, and highly proliferative. Thus, this system may have a potential use in the development of synthetic seed and transgenic papaya plants. Details of important factors affecting somatic embryogenesis will be discussed.


2017 ◽  
Vol 9 (4) ◽  
pp. 352-360
Author(s):  
SUPATMI SUPATMI ◽  
HANI FITRIANI ◽  
NURHAMIDARR RAHMAN ◽  
N. SRI HARTATI ◽  
ENNY SUDARMONOWATI

Supatmi, Fitriani H, Rahman N, Hartati NS, Sudarmonowati E. 2017. Robust in vitro propagation and regeneration of ubi kuning high beta carotene cassava genotype through somatic embryogenesis. Nusantara Bioscience 9: 352-360. Ubi kuning is a local genotype of cassava with high beta carotene content but the development of this genotype is still low because of plant disease susceptibility. Objectives of this study were to robust induce and regenerate somatic embryos of ubi kuning in vitro as well as to define a protocol of cyclic somatic embryogenesis of ubi kuning. Different size of leaf lobes, various concentration of picloram and different light conditions were tested to produce an effective and efficient somatic embryos (SEs).The best response of the induction of embryogenic callus was observed in leaf lobes explant with range size of 1-3 mm and >5mm cultured on induction medium (MS + 4% sucrose + 4 μM CuSO4 + 0.1 mM Glutamine + 0.8% Microagar) supplemented with either 10 or 18 mg/L picloram grown under dark light for 4 weeks. Retransferring embryogenic callus to the same medium supplemented with 16 mg/L picloram gave the advanced development of primary somatic embryos (PSEs) after 70 d grown under both dark and light condition treatments. A positive correlation between globular and cotyledon stages was obtained in all treatments (P≤ 0.01). The highest shoot and root growth (30% and 25%) was achieved in the regeneration of cotyledonary like-tissues cultured on callus embryogenic media (CEM) (MS basal+ 2.5 μM CuSO4 + 3% sucrose + 2.75 g/L phytagel) supplemented with 1.6 mg/L of BAP (6-Benzylaminopurine).


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1078A-1078
Author(s):  
Qian Zhang ◽  
Jianjun Chen ◽  
Richard J. Henny

Homalomena `Emerald Gem' is an important ornamental foliage plant and widely used for interior plantscaping. Current propagation of this cultivar has been primarily carried out through in vitro culture by organogenesis; regeneration through somatic embryogenesis has not been documented. This report describes successful plant regeneration via direct somatic embryogenesis from explants of different organs. Somatic embryos formed at and around the cut surface of petiole, spathe, and peduncle explants. Embryos also appeared at the base between expanded ovaries of the spadix segment, and around midrib of leaf explants. The optimal treatments for somatic embryo occurrence from petiole, spathe, and peduncle explants were MS medium containing 0.2 mg/L NAA or 0.5 mg/L 2, 4-D with 2.0 mg/L CPPU, and for spadix explants were MS medium with 0.5 mg/L PAA and 2.5 mg/L TDZ. Somatic embryos appeared 6 to 8 weeks after culture and formed large embryo clumps in 3 to 4 months. Somatic embryos produced more secondary embryos and geminated on induction medium. Multiple shoot development and plant regeneration occurred from somatic embryo clusters on MS medium without hormone or with 2 mg/L BA and 0.2 mg/L NAA. The regenerated plants grew vigorously after transplanting to a soilless container substrate in a shaded greenhouse.


2017 ◽  
Vol 27 (1) ◽  
pp. 21-31 ◽  
Author(s):  
Mustafa Abul Kalam Azad ◽  
Muhammad Nurul Amin

A plant regeneration system was established from hypocotyl explants of in vitro grown seedlings of A. officinalis and in vitro proliferated shoots, respectively through somatic embryogenesis and embryogenic calli. Somatic embryogenesis was significantly influenced by the types of plant growth regulators. Embryogenic calli with somatic embryos developed well in MS supplemented with 2.0 ‐ 4.0 μM BAP and 1.0 ‐ 4.0 μM 22,4‐D, NAA or IBA. The highest frequency (95.3%) of embryogenic calli and 55.2 somatic embryos formation were obtained when the MS was amended with 4.0 μM BAP and 2.0 μM 2,4‐D. The best embryo germination occurred in 1.0 μM BAP supplemented MMS. The highest 97.2% of shoot proliferation was observed in embryogenic calli in MS medium containing 2.0 μM BAP and 1.0 μM IBA. In vitro grown shoots were rooted in MMS with 1.0 ‐ 2.0 μM IBA. Regenerants were transferred to vermicompost and successfully established under an ex vitro environment in garden soil with 80% survival rate.Plant Tissue Cult. & Biotech. 27(1): 21-31, 2017 (June)


2007 ◽  
Vol 50 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Terezinha Feitosa ◽  
João Luíz Pinheiro Bastos ◽  
Luíz Ferreira Aguiar Ponte ◽  
Thiago Lustosa Jucá ◽  
Francisco de Assis de Paiva Campos

A method for the induction of somatic embryogenesis in eight cassava genotypes from northeastern Brazil is described. The explants used were shoot apexes isolated both from in vitro grown plants and from shoots that sprouted from stem cuttings. Somatic embryogenesis was achieved in high frequencies by the addition in the induction medium of the auxin picloram over a wide range of concentrations. Green cotyledons of primary somatic embryos were used as explants to induce somatic (cyclic) secondary embryogenesis in an inducing medium supplemented with picloram at 12 mg/L. The method could be used not only for the mass production of plants of the cassava genotypes, but also to generate explants (green cotyledons of somatic embryos) as themselves excellent targets for genetic transformation.


HortScience ◽  
2010 ◽  
Vol 45 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Inmaculada Vila ◽  
Ester Sales ◽  
Javier Ollero ◽  
Jesús Muñoz-Bertomeu ◽  
Juan Segura ◽  
...  

Successful propagation of Nerium oleander L. (oleander) was achieved by in vitro methods. Shoot cultures were initiated from seedlings of wild-growing plants and from shoot apices of adult plants belonging to the commercial cultivars Splendens Giganteum, Revanche, and Alsace. Axillary shoot breaking from shoot tips excised from these cultures required the presence of either 6-benzylaminopurine (BA) or thidiazuron (TDZ). The higher number of axillary shoots from juvenile material was obtained by culturing shoot tips from BA-pretreated material derived from seedlings on a modified Schenk and Hildebrandt medium (SHM) supplemented with BA or TDZ (average of 3.9 shoots per explant with a mean length of 10.4 mm) and when the media were supplemented with 8.8 μM TDZ (average of 3.5 shoots per explant with a mean length of 7.3 mm) or 4.4 μM BA (average of 3.3 shoots per explant with a mean length of 12.3 mm). Among cultivars, cv. Revanche showed best shoot proliferation rates, especially when explants were cultured on Woody Plant Medium (average of 3.2 shoots per explant with a mean length of 10.2 mm). Adventitious bud differentiation from oleander leaves is also reported. Leaves excised from seedling-derived shoot cultures responded better than those from adult plant-derived shoot cultures (40% versus 5%, respectively). Bud differentiation required the presence of TDZ in the SHM medium, although shoot development was only achieved on transference of explants to media without TDZ but supplemented with BA and indoleacetic acid (IAA) or BA, kinetin, and IAA. Axillary and adventitious shoots were easily rooted (99%) and successfully (95% to 100%) transferred to soil.


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