Acessibilidade / Reportar erro

TDZ and 2,4-D on in vitro propagation of panda plant from leaf explants

TDZ e 2,4-D na propagação in vitro de planta de panda a partir de explantes de folhas

Abstract

The panda plant (Kalanchoe tomentosa Baker) is a popular ornamental succulent. The optimal method for in vitro plantlet propagation was investigated. Effects of plant growth regulator on growth and development of leaf explants were determined using various concentrations of Thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D) at 0, 0.01, 0.1, 0.2 and 0.5 mg L-1. A concentration of 0.01 mg L-1 2,4-D gave the highest plantlet quality derived from direct organogenesis. Higher concentrations of 2,4-D promoted callus proliferation. The lowest concentration of 0.01 mg L-1 TDZ induced shorter shoots, while higher concentrations resulted in greater callogenesis and inhibit root production. After in vitro culture, plantlets from the optimal treatment were acclimatized by exposure to growth in sand, sand with coconut husk (2:1), sand with potting soil (2:1) and sand with perlite (2:1). Highest survival percentage (100%) was found in plantlets grown in sandy soil, the most well-drained material of those selected materials. Results demonstrated an alternative production method for panda plantlets using plant tissue culture techniques.

Keywords:
Kalanchoe tomentosa; in vitro propagation; plant growth regulator; plantlet acclimatization; succulent plant

Resumo

A planta panda (Kalanchoe tomentosa Baker) é uma suculenta ornamental popular. O método para a propagação de plântulas in vitro foi investigado. Os efeitos do regulador de crescimento de plantas no crescimento e desenvolvimento de explantes de folhas foram determinados usando várias concentrações de Thidiazuron (TDZ) e ácido 2,4-diclorofenoxiacético (2,4-D) a 0; 0,01; 0,1; 0,2 e 0,5 mg L-1. A concentração de 0,01 mg L-1 de 2,4-D proporcionou a maior qualidade de mudas derivada da organogênese direta. Concentrações mais elevadas de 2,4-D promoveram a proliferação de calos. A menor concentração de 0,01 mg L-1 de TDZ induziu brotações mais curtas, enquanto concentrações maiores resultaram em maior calogênese e inibiram a produção de raízes. Após o cultivo in vitro, as plântulas do tratamento ótimo foram aclimatadas por exposição ao crescimento em areia, areia com casca de coco (2:1), areia com solo para envasamento (2:1) e areia com perlita (2:1). A maior porcentagem de sobrevivência (100%) foi encontrada em mudas cultivadas em solo arenoso, o material mais bem drenado dos materiais selecionados. Os resultados demonstraram um método alternativo de produção de mudas de panda usando técnicas de cultura de tecidos de plantas.

Palavras-chave:
Kalanchoe tomentosa; propagação in vitro; regulador de crescimento vegetal; aclimatação de plântulas; planta suculenta

Introduction

The panda plant, Kalanchoe tomentosa Baker, belongs to the family Crassulaceae that comprises 35 genera and some 1400 species. This perennial succulent has distinct hairy velvet leaves and is found naturally in rocky areas of central and southern central Madagascar. The attractive characteristic of the leaves has promoted K. tomentosa as an indoor ornamental plant. This succulent is usually used as potting plant and container gardening (Smith et al., 2019SMITH, G.F.; FIGUEIREDO, E.; VAN WYK, A.E. Kalanchoe (Crassulaceae) in Southern Africa. Cambridge: Academic Press, 2019. p.338.). Alternatively, the panda plant has an important substance that can be applied for medicinal uses such as anticancer and antidiabetes (Aisyah et al., 2015AISYAH, L.S.; YUN, Y.F.; JULAEHA, E.; HERLINA, T.; ZAINUDDIN, A.; HERMAWAN, W.; SUPRATMAN, U.; HAYASHI, H. Flavonoids from the fresh leaves of Kalanchoe tomentosa (Crassulaceae). Open Chemistry Journal, v.2, p.36-39, 2015. DOI: https://doi.org/10.2174/1874842201502010036
https://doi.org/10.2174/1874842201502010...
; 2020AISYAH, L.S.; ILFANI, D.; LESTARI, F.P.; YUN, Y.F. α-amylase inhibition activities by flavonoid compounds from panda plants (Kalanchoe tomentosa). Jurnal Kimia Sains dan Aplikasi, v.23, n.3, p.96-101, 2020. DOI: https://doi.org/10.14710/jksa.23.3.96-101
https://doi.org/10.14710/jksa.23.3.96-10...
). propagation of K. tomentosa is usually handled by leaf and stem cutting, however, the donor plants can be deteriorated. With an increasing demand on ornamental succulents (Stead, 2016STEAD, J. The succulent garden story. Cactus and Succulent Journal, v.88, n.5, p.260-263, 2016.), the plantlet production may be inadequate. An alternative method that can produce numerous plantlets in short time is archived by plant tissue culture. In vitro propagation has been reported in several Kalanchoe species (Kulus, 2015KULUS, D. Micropropagation of Kalanchoe tubiflora (Harvey) Hamet. Nauka Przyroda Technologie, v.9, n.1, p.1-8, 2015. DOI: https://dx.doi.org/10.17306/J.NPT.2015.1.14
https://dx.doi.org/10.17306/J.NPT.2015.1...
; Kale et al., 2018KALE, M.S.; HAKE, A.A.; THAKUR, P.P. In vitro regeneration and rapid multiplication of Kalanchoe blossfeldiana: An important ornamental plant. International Journal of Chemistry, v.6, n.5, p.2509-2512, 2018. ; Cui et al., 2019CUI, J.; MACKENZIE, K.K.; EECKHAUT, T.; MULLER, R.; LUTEKEN, H. Protoplast isolation and culture from Kalanchoe species: optimization of plant growth regulator concentration for efficient callus production. Plant Cell Tissue and Organ Culture, v.138, p.287-297, 2019. DOI: https://doi.org/10.1007/s11240-007-9226-3
https://doi.org/10.1007/s11240-007-9226-...
) but there are few reports for panda plant (Frello et al., 2002FRELLO, S.; VENERUS, E.; SEREK, M. Regeneration of various species of Crassulaceae, with special reference to Kalanchoe. Journal of Horticultural Science and Biotechnology, v.77, n.2, p.204-208, 2002. DOI: https://doi.org/10.1080/14620316.2002.11511480
https://doi.org/10.1080/14620316.2002.11...
; Khan et al., 2006KHAN, S.; NAZ, S.; ALI, K.; ZAIDI, S. Direct organogenesis of Kalanchoe tomentosa (Crassulaceae) from shoot tip. Pakistan Journal of Botany, v.38, n.4, p.977-981, 2006.). For success in plant micropropagation in vitro, suitable techniques must be followed as many factors affect plant tissue culture including the effects of plant growth regulators (PGRs).

Thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D) as synthetic PGRs are widely used for tissue culture in many plant species. Optimal concentration of PGRs enhances high crop yield. In Kalanchoe species, TDZ applied to induce the production of numerous shoots depending on concentration and explant cultivar (Sanikhani et al., 2006SANIKHANI, M.; FRELLO, S.; SEREK, M. TDZ induces shoot regeneration in various Kalanchoe blossfeldiana Poelln. cultivars in the absence of auxin. Plant Cell Tissue and Organ Culture , v.85, p.75-82, 2006.). TDZ also induced explants of a Kalanchoe species to regenerate callus (Kertrung and Junkasiraporn, 2018KERTRUNG, T.; JUNKASIRAPORN, S. In vitro propagation of Kalanchoe rhombopilosa (Crassulaceae). NU International Journal of Science, v.15, n.1, p.37-48, 2018.); however, the effect of TDZ concentration on in vitro culture of K. tomentosa Baker has not yet been examined. Another synthetic PGR, 2,4-D is also used for callus induction in many plant species (Machakova et al., 2008MACHAKOVA, I.; ZAZIMALOVA, E.; GEORGE, E.F. Plant growth regulators: introduction; auxins, their analogues and inhibitors. In: GEORGE, E.F.; HALL, M.A.; KLERK, DE G-J. (Eds.), Plant propagation by tissue culture (3rd ed.). Netherlands: Springer, 2008. p.275-374.) and its effects have not been reported on in vitro culture of K. tomentosa. Understanding about the effects of those PGRs on explant responses may improve the plantlet production in vitro of the panda plant. One of the limitations on plant tissue culture is plantlet exposure ex vitro because high mortality may be occurred in this process. For the successfully propagation, the plantlet acclimatization ex vitro should be investigated (Vahdati et al., 2017VAHDATI, K.; ASAYESH, Z.M.; ALINIAEIFARD, S.; LESLIE, C. Improvement of ex vitro desiccation through elevation of CO2 concentration in the atmosphere of culture vessels during in vitro growth. HortScience, v.52, n.7, p.1006-1012, 2017. DOI: https://doi.org/10.21273/HORTSCI11922-17
https://doi.org/10.21273/HORTSCI11922-17...
).

Thus, here, the effects of different concentrations of TDZ and 2,4-D were examined on in vitro propagation of K. tomentosa leaf explants to optimize plantlet production. Also, the optimal planting materials for plantlet acclimatization were investigated. The improvement of K. tomentosa plantlets by plant tissue culture techniques was reported here.

Material and Methods

Plant materials and media preparation

Plant materials were purchased from a local market and grown in a greenhouse for one week. Four leaves were collected from each plant as the fourth to the seventh leaves from the shoot apex. The leaves were washed in tap water with 1% (v v-1) commercial surfactant (Sunlight®) and rinsed in running tap water for 30 min. Then, the cleaned leaves were surface-disinfected by a series of 70% (v v-1) ethanol for 1 min, 0.01% (w v-1) mercuric chloride solution with 1% (v v-1) Tween 20 for 5 min, and 10% commercial hypochlorite solution (Clorox®) for 10 min. disinfected leaves were washed aseptically three times in distilled water. Ventral sides of the leaves were placed on the surface of semi-solid MS (Murashige and Skoog, 1962MURASHIGE, T.; SKOOG, F. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiologia Plantarum, v.15, p.473-497, 1962. DOI: https://doi.org/10.1111/j.1399-3054.1962.tb08052.x
https://doi.org/10.1111/j.1399-3054.1962...
) basal medium supplemented with 0.5 ml L-1 plant preservative mixture (PPMTM; Plant Cell Technology). The explants were then incubated at 25 ± 2 °C under 40 μmol m-2 s-1 light intensity (provided by cool white LED tubes) and 12 h light photoperiod. Regenerated shoots were subcultured on MS basal medium and aseptic plants were used as explant material in further experiments.

The widely used MS basal medium was applied containing 30 g L-1 sucrose (MitrPhol®), 0.1 g L-1 myo-inositol (Phytotechnology Laboratory®) and 7 g L-1 agar (AA, Pearl Mermaid®). The pH of the medium was adjusted to 5.8 before autoclaving (121 °C, 15 psi and 20 min).

Effects of plant growth regulator on growth and development of leaf explants

Leaf explants at about 5×5 mm2 from aseptic culture were randomly applied in the experiment, and cultured on MS media supplemented with different concentrations (0, 0.01, 0.1, 0.2 and 0.5 mg L-1) of TDZ and 2,4-D. Each treatment was applied to one explant per bottle. All treatments were incubated at 25 ± 2 °C at 40 μmol m-2 s-1 light intensity and 12-h light photoperiod. Growth and development parameters of the explants were observed after culture for 4, 8 and 12 weeks.

Plantlet acclimatization ex vitro

Healthy plantlets (new shoots with active root), induced by MS with 0.01 mg L-1 2,4-D, about 2 cm high from the previous experiment were applied in this experiment (Figure 4a). Each plantlet individuals were separated carefully from each other by scalpel. The plantlets were rinsed in running tap water and then submerged in 0.5% (w v-1) fungicide solution for 15 min. Disinfected plantlets were transplanted into four different planting materials including sand, sand with coconut husk (2:1), sand with potting soil (2:1) and sand with perlite (2:1). A total of 25 plantlets were randomly assigned for each treatment. After transplantation, the plantlets were grown in a greenhouse (27 to 30 °C ambient temperature, 50% to 60% relative humidity and 50% (sunlight) transparency). The plantlets were watered by a spray pump for 1-h twice a day. Survival rate and plantlet quality were recorded weekly for 10 weeks.

Statistical analysis

All growth and development parameters of the in vitro experiment were analyzed by one-way ANOVA and post-hoc using Duncan’s new multiple range test (DMRT) with SPSS version 22. To normalize the data distribution, the percentage data were arcsine transformed before analysis.

Results

Effects of plant growth regulator on growth and development of leaf explants

After culture for 4 weeks, direct organogenesis was observed in most explants except those cultured on MS medium supplemented with 0.2 and 0.5 mg L-1 TDZ. Direct organogenesis was displayed as the occurrence of root(s) from the cut end of the explants (Figure 1).

Figure 1
Growth and development of Kalanchoe tomentosa explants cultured on different PGR treatments after 4, 8 and 12 weeks (bar = 1 cm)

After culture for 8 weeks, shoot regeneration ranging from 53.3 to 83.3% was found in 0.01 mg L-1 TDZ, 0.01, 0.1, 0.2 and 0.5 mg L-1 2,4-D and the control treatments (Figures. 1 and 2).

Figure 2
Growth and development of Kalanchoe tomentosa explants; percentage of shoot regeneration (top) and percentage of callus formation (bottom), cultured on different PGR treatments after 8 weeks (left) and 12 weeks (right). Bars and error bars show mean ± SE of three replications (ten explants per replication at week 8 and nine explants per replication at week 12). Different letters above the bar indicate significant differences by DMRT at p ≤ 0.05.

Highest shoot number (1.9 shoots) was observed in the 0.01 mg L-1 2,4-D treatment; however, there were no significant differences between 0.01 mg L-1 TDZ, 0.1 and 0.2 mg L-1 2,4-D and the control treatments (data not shown).

Shoots emerged from the cut scars of the explants (Figure 3a). The remaining treatments (0.1, 0.2 and 0.5 mg L-1 TDZ) had no shoot production and showed callus formation (Figures 1 and 2). Highest percentage (83.3%) of callus formation was found in 0.2 and 0.5 mg L-1 TDZ treatments followed by 0.1 and 0.5 mg L-1 TDZ (Figure 2). All calluses were friable and emerged from cut scars of the explants and did not differentiate (Figure 3b).

Figure 3
Shoot regeneration (a; bar = 5 mm), callus formation (b; bar = 5 mm), and healthy plantlet (c; bar = 1 cm) of Kalanchoe tomentosa

At week 12 of culture, shoot regeneration was observed on MS medium supplemented with 0.01 mg L-1 TDZ, 0.01, 0.1, 0.2, 0.5 mg L-1 2,4-D and the control except for 0.1, 0.2 and 0.5 mg L-1 TDZ (Figure 1). Shoot regeneration ranged from 66.3 to 100% (Figure 2). Highest shoot number (4 shoots) was found in 0.01 mg L-1 TDZ; however, no significant differences were found among shoot regeneration treatments (Table 1).

Table 1
Growth and development of Kalanchoe tomentosa explants cultured on different PGR treatments after 12 weeks.

Callus formation was observed in all treatments, except for 0.01 and 0.1 mg L-1 2,4-D and the control. The percentage of callus formation varied from 4.2 to 100% (Figure 2). The root regeneration without shooting was found on explants treated by MS medium with 0.1 mg L-1 TDZ. The three treatments that induced the highest plant height, leaf number and rooting percentage were 0.01 and 0.1 mg L-1 2,4-D and the control but with no significant differences. MS medium supplemented with 0.01 mg L-1 2,4-D (Figure 3a and Table 1) induced the healthiest plantlets of K. tomentosa with a significant difference in root numbers per explant.

Plantlet acclimatization ex vitro

Ten weeks after the acclimatization of healthy plantlets of K. tomentosa, survival percentage varied from 50% to 100%. Highest survival percentage (100%) was found for plantlets grown in sand, while survival percentages of plantlets grown in sand with coconut husk, sand with potting soil and sand with perlite were 88, 76 and 56%, respectively. Plantlet quality in different planting materials is depicted in Figure 4b-e.

Figure 4
Kalanchoe tomentosa plantlets before transplantation (a) and after transplantation in different planting materials; sand (b), 2:1 sand with fine coconut husk (c), 2:1 sand with perlite (d), and 2:1 sand with potting soil (e) for 10 weeks (bar = 1 cm).

Throughout the acclimatization, survival percentages in each treatment were decreased except plantlets grown in sand. On 2:1 ratio of sand per perlite, the survival percentage dramatically decreased in week 5 after acclimatization while other treatments the percentage slightly decreased to stable (Table 2).

Table 2
Weekly survival pecentage of Kalanchoe tomentosa on different planting materials in the acclimatization for 10 weeks (n = 25).

Discussion

Low concentration (0.01 mg L-1) of TDZ induced new shoot regeneration, however, using TDZ resulted in shorter plantlets than MS without PGR treatment (Table 1). Higher concentrations of TDZ gave increased callus formation with faster callogenesis (Fig. 2). The same result was found in other ornamental succulents, where TDZ promoted callus formation (Liu et al., 2016LIU, B.; ZHANG, Y.; ZHANG, K.; FANG, H.; ZHANG, X.; FU, R.; QIU, X.; XU, R. The efficient tissue culture system of Orostachys fimbriata. Agricultural Sciences, v.7, p.175-180, 2016. DOI: https://dx.doi.org/10.4236/as.2016.73017
https://dx.doi.org/10.4236/as.2016.73017...
; 2017LIU, B.; FANG, H.; MENG, C.; CHEN, M.; CHAI, Q.; ZHANG, K.; LIU, S. Establishment of a Rapid and Efficient micropropagation system for succulent plant Haworthia turgida Haw. HortScience, v.52, n.9, p.1278-1282, 2017. DOI: https://dx.doi.org/10.21273/HORTSCI12056-17
https://dx.doi.org/10.21273/HORTSCI12056...
). In K. rhombopilosa Mannoni & Boiteau, higher TDZ concentration increased the callogenesis rate and decreased the differentiation rate (Kertrung and Junkasiraporn, 2018KERTRUNG, T.; JUNKASIRAPORN, S. In vitro propagation of Kalanchoe rhombopilosa (Crassulaceae). NU International Journal of Science, v.15, n.1, p.37-48, 2018.). Callus induction might be due to that TDZ stimulated cell division in plant cell more than other PGRs. TDZ also increase the level of endogenous cytokinin by reducing catabolism, increasing synthesis, and conversing inactive cytokinin to active forms (Dinani et al. 2018DINANI, E.T.; SHUKLA, M.R.; TURI, C.E.; SULIVAN, J.A.; SAXENA, P.K. Thidiazuron: modulator of morphogenesis in vitro. In: AHMAD, N.; FAISAL, M. (Eds.). Thidiazuron: from urea derivative to plant growth regulator. Singapore: Springer, 2018. p.1-36.). By contrast, TDZ induced shoots regeneration in Kalanchoe blossfeldiana Poelln. and Sedum sarmentosum Bunge, while callus formation was not recorded (Sanikhani et al., 2006SANIKHANI, M.; FRELLO, S.; SEREK, M. TDZ induces shoot regeneration in various Kalanchoe blossfeldiana Poelln. cultivars in the absence of auxin. Plant Cell Tissue and Organ Culture , v.85, p.75-82, 2006.; Kim and Sivanessan, 2016KIM, D.H.; SIVANESSAN, I. Influence of benzyladenine and thidiazuron on shoot regeneration from leaf and shoot tip explants of Sedum sarmentosum Bunge. Brazilian Archives of Biology and Technology, v.59, artigo e16150717, 2016. DOI: https://dx.doi.org/10.1590/1678-4324-2016150717
https://dx.doi.org/10.1590/1678-4324-201...
). In K. tomentosa Baker, MS medium supplemented with 0.25 mg L-1 TDZ and 0.4 mg L-1 indole-3-acetic acid (IAA) induced new shoot regeneration at only 30% (Frello et al., 2002FRELLO, S.; VENERUS, E.; SEREK, M. Regeneration of various species of Crassulaceae, with special reference to Kalanchoe. Journal of Horticultural Science and Biotechnology, v.77, n.2, p.204-208, 2002. DOI: https://doi.org/10.1080/14620316.2002.11511480
https://doi.org/10.1080/14620316.2002.11...
). Responses of Kalanchoe species varied with TDZ and the optimal quantity should be examined in each application. In our study, the present of root without shoot regeneration found on MS medium supplemented with 0.1 mg L-1 TDZ might be due to the consequence of explants development. An evidence was supported by the organogenesis at week 4 that root was the first occurrence organ in most explants of this study. From our result also revealed that higher TDZ concentration reduced root development.

Low concentration (0.01 mg L-1) of 2,4-D promoted the highest quality plantlets, while higher concentrations increased the callogenesis rate (Figure 2). 2,4-D is usually used with cytokinins for callus induction. The induction of callogenesis was also confirmed in K. blossfeldiana Poelln. and Digitalis lanata Ehrh. (Kale et al., 2018KALE, M.S.; HAKE, A.A.; THAKUR, P.P. In vitro regeneration and rapid multiplication of Kalanchoe blossfeldiana: An important ornamental plant. International Journal of Chemistry, v.6, n.5, p.2509-2512, 2018. ; Bhusare et al., 2020BHUSARE, B.P.; JOHN, C.K.; BHATT, V.P.; NIKAM, T.D. Induction of somatic embryogenesis in leaf and root explants of Digitalis lanata Ehrh.: Direct and indirect method. South African Journal of Botany, v.130, p.356-365, 2020. DOI: https://doi.org/10.1016/j.sajb.2020.01.012.
https://doi.org/10.1016/j.sajb.2020.01.0...
). However, our results suggest that 2,4-D at low concentration may induce plantlet formation. 2,4-D is an auxin and plays a primary role in cell elongation and root initiation (Machakova et al., 2008MACHAKOVA, I.; ZAZIMALOVA, E.; GEORGE, E.F. Plant growth regulators: introduction; auxins, their analogues and inhibitors. In: GEORGE, E.F.; HALL, M.A.; KLERK, DE G-J. (Eds.), Plant propagation by tissue culture (3rd ed.). Netherlands: Springer, 2008. p.275-374.). The response of explants in this study might be due to the auxin-cytokinin balance derived from exogenous auxin (2,4-D) and endogenous auxin cytokinin in plant cells.

Plantlet acclimatization ex vitro results indicated that planting material affected survival rate. Proper planting material should be a major concern for each application. Many reports of Kalanchoe species on plantlet acclimatization ex vitro from in vitro culture have indicated over 90% survival rate (Khan et al., 2006KHAN, S.; NAZ, S.; ALI, K.; ZAIDI, S. Direct organogenesis of Kalanchoe tomentosa (Crassulaceae) from shoot tip. Pakistan Journal of Botany, v.38, n.4, p.977-981, 2006.; Sanikhani et al., 2006SANIKHANI, M.; FRELLO, S.; SEREK, M. TDZ induces shoot regeneration in various Kalanchoe blossfeldiana Poelln. cultivars in the absence of auxin. Plant Cell Tissue and Organ Culture , v.85, p.75-82, 2006.). Our results indicated that the best planting material for K. tomentosa was sandy soil. High plantlet quality observed in sand insists that well-drained planting material is appropriate for growing panda plant (Smith et al., 2019SMITH, G.F.; FIGUEIREDO, E.; VAN WYK, A.E. Kalanchoe (Crassulaceae) in Southern Africa. Cambridge: Academic Press, 2019. p.338.) while higher water absorbed materials reduce survival rate.

Conclusions

Our result demonstrated an alternative production method for panda plantlets using plant tissue culture techniques. Experimental results identified 2,4-D as a candidate plant growth regulator (PGR) for leaf explant culture in vitro of panda plant. 2,4-D gave a highly quality plantlet with increased plant height, leaves and root numbers per explant than TDZ. The suggested medium was MS medium supplemented with 0.01 mg L-1 2,4-D. Our protocol produced 2-4 shoots per explant but might be compensated by lower disturbance on plant individuals when leaf explants were deployed. To produce calluses of panda plants, MS medium supplemented with 0.2 mg L-1 TDZ is recommended. For ex vitro acclimatization, sand is suitable for promoting more survival rate.

Acknowledgements

This research was supported by the Faculty of Science, Srinakharinwirot University, Thailand (Grant number 469/2562). The first author is indebted to the Plant Tissue Culture Research Unit, Faculty of Science, Naresuan University for assistance with the laboratory work. Thanks are also due to Miss B. Rakchart and Miss A. Somanachangphueak for their help in conducting the preliminary experiments.

References

  • AISYAH, L.S.; YUN, Y.F.; JULAEHA, E.; HERLINA, T.; ZAINUDDIN, A.; HERMAWAN, W.; SUPRATMAN, U.; HAYASHI, H. Flavonoids from the fresh leaves of Kalanchoe tomentosa (Crassulaceae). Open Chemistry Journal, v.2, p.36-39, 2015. DOI: https://doi.org/10.2174/1874842201502010036
    » https://doi.org/10.2174/1874842201502010036
  • AISYAH, L.S.; ILFANI, D.; LESTARI, F.P.; YUN, Y.F. α-amylase inhibition activities by flavonoid compounds from panda plants (Kalanchoe tomentosa). Jurnal Kimia Sains dan Aplikasi, v.23, n.3, p.96-101, 2020. DOI: https://doi.org/10.14710/jksa.23.3.96-101
    » https://doi.org/10.14710/jksa.23.3.96-101
  • BHUSARE, B.P.; JOHN, C.K.; BHATT, V.P.; NIKAM, T.D. Induction of somatic embryogenesis in leaf and root explants of Digitalis lanata Ehrh.: Direct and indirect method. South African Journal of Botany, v.130, p.356-365, 2020. DOI: https://doi.org/10.1016/j.sajb.2020.01.012
    » https://doi.org/10.1016/j.sajb.2020.01.012
  • CUI, J.; MACKENZIE, K.K.; EECKHAUT, T.; MULLER, R.; LUTEKEN, H. Protoplast isolation and culture from Kalanchoe species: optimization of plant growth regulator concentration for efficient callus production. Plant Cell Tissue and Organ Culture, v.138, p.287-297, 2019. DOI: https://doi.org/10.1007/s11240-007-9226-3
    » https://doi.org/10.1007/s11240-007-9226-3
  • DINANI, E.T.; SHUKLA, M.R.; TURI, C.E.; SULIVAN, J.A.; SAXENA, P.K. Thidiazuron: modulator of morphogenesis in vitro In: AHMAD, N.; FAISAL, M. (Eds.). Thidiazuron: from urea derivative to plant growth regulator. Singapore: Springer, 2018. p.1-36.
  • FRELLO, S.; VENERUS, E.; SEREK, M. Regeneration of various species of Crassulaceae, with special reference to Kalanchoe Journal of Horticultural Science and Biotechnology, v.77, n.2, p.204-208, 2002. DOI: https://doi.org/10.1080/14620316.2002.11511480
    » https://doi.org/10.1080/14620316.2002.11511480
  • KALE, M.S.; HAKE, A.A.; THAKUR, P.P. In vitro regeneration and rapid multiplication of Kalanchoe blossfeldiana: An important ornamental plant. International Journal of Chemistry, v.6, n.5, p.2509-2512, 2018.
  • KERTRUNG, T.; JUNKASIRAPORN, S. In vitro propagation of Kalanchoe rhombopilosa (Crassulaceae). NU International Journal of Science, v.15, n.1, p.37-48, 2018.
  • KHAN, S.; NAZ, S.; ALI, K.; ZAIDI, S. Direct organogenesis of Kalanchoe tomentosa (Crassulaceae) from shoot tip. Pakistan Journal of Botany, v.38, n.4, p.977-981, 2006.
  • KIM, D.H.; SIVANESSAN, I. Influence of benzyladenine and thidiazuron on shoot regeneration from leaf and shoot tip explants of Sedum sarmentosum Bunge. Brazilian Archives of Biology and Technology, v.59, artigo e16150717, 2016. DOI: https://dx.doi.org/10.1590/1678-4324-2016150717
    » https://dx.doi.org/10.1590/1678-4324-2016150717
  • KULUS, D. Micropropagation of Kalanchoe tubiflora (Harvey) Hamet. Nauka Przyroda Technologie, v.9, n.1, p.1-8, 2015. DOI: https://dx.doi.org/10.17306/J.NPT.2015.1.14
    » https://dx.doi.org/10.17306/J.NPT.2015.1.14
  • LIU, B.; ZHANG, Y.; ZHANG, K.; FANG, H.; ZHANG, X.; FU, R.; QIU, X.; XU, R. The efficient tissue culture system of Orostachys fimbriata Agricultural Sciences, v.7, p.175-180, 2016. DOI: https://dx.doi.org/10.4236/as.2016.73017
    » https://dx.doi.org/10.4236/as.2016.73017
  • LIU, B.; FANG, H.; MENG, C.; CHEN, M.; CHAI, Q.; ZHANG, K.; LIU, S. Establishment of a Rapid and Efficient micropropagation system for succulent plant Haworthia turgida Haw. HortScience, v.52, n.9, p.1278-1282, 2017. DOI: https://dx.doi.org/10.21273/HORTSCI12056-17
    » https://dx.doi.org/10.21273/HORTSCI12056-17
  • MACHAKOVA, I.; ZAZIMALOVA, E.; GEORGE, E.F. Plant growth regulators: introduction; auxins, their analogues and inhibitors. In: GEORGE, E.F.; HALL, M.A.; KLERK, DE G-J. (Eds.), Plant propagation by tissue culture (3rd ed.). Netherlands: Springer, 2008. p.275-374.
  • MURASHIGE, T.; SKOOG, F. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiologia Plantarum, v.15, p.473-497, 1962. DOI: https://doi.org/10.1111/j.1399-3054.1962.tb08052.x
    » https://doi.org/10.1111/j.1399-3054.1962.tb08052.x
  • SANIKHANI, M.; FRELLO, S.; SEREK, M. TDZ induces shoot regeneration in various Kalanchoe blossfeldiana Poelln. cultivars in the absence of auxin. Plant Cell Tissue and Organ Culture , v.85, p.75-82, 2006.
  • SMITH, G.F.; FIGUEIREDO, E.; VAN WYK, A.E. Kalanchoe (Crassulaceae) in Southern Africa. Cambridge: Academic Press, 2019. p.338.
  • STEAD, J. The succulent garden story. Cactus and Succulent Journal, v.88, n.5, p.260-263, 2016.
  • VAHDATI, K.; ASAYESH, Z.M.; ALINIAEIFARD, S.; LESLIE, C. Improvement of ex vitro desiccation through elevation of CO2 concentration in the atmosphere of culture vessels during in vitro growth. HortScience, v.52, n.7, p.1006-1012, 2017. DOI: https://doi.org/10.21273/HORTSCI11922-17
    » https://doi.org/10.21273/HORTSCI11922-17
  • Area Editor: Fernanda Carlota Nery

Author Contribution

  • WP: conceptualization, experiment development, data analysis and interpretation, manuscript writing and corrections, ON: data collection, preliminary analysis and interpretation, AK: review and editing.

Publication Dates

  • Publication in this collection
    23 Nov 2020
  • Date of issue
    Jan-Mar 2021

History

  • Received
    30 Aug 2020
  • Accepted
    07 Oct 2020
  • Published
    04 Nov 2020
Sociedade Brasileira de Floricultura e Plantas Ornamentais Av. Av. Peter Henry Rolfs, s/n, 36570-000 - Viçosa, Minas Gerais - Brasil, (32) 3379-4983, Tel: (32) 3379-4983 - Viçosa - MG - Brazil
E-mail: editor.ornamentalhorticulture@gmail.com