In vitro propagation, ex vitro rooting and leaf micromorphology of Bauhinia racemosa Lam.: a leguminous tree with medicinal values

Control of media browning during micropropagation and assessment of biochemical and clonal fidelity of in vitro-derived and mother plants in Thottea siliquosa (Lamk.) Ding Hou., an important ethnomedicinal shrub

BACKGROUND

Thottea siliquosa (Lamk.) Ding Hou., an important medicinal shrub, is widely used in both ayurvedic and indigenous systems of medicine. Root being the most useful part, the plant is constantly uprooted and thus puts pressure on the natural population. Until date, no micropropagation study is available in this plant. The objective of the study is to develop an efficient in vitro propagation protocol and assessment of clonal fidelity of T. siliquosa.

RESULTS

Media browning was a serious issue during micropropagation, and the addition of 40.0 mg/L ascorbic acid reduced the media browning. For direct shoot regeneration, the optimum response (92% frequency with 20.9 shoots per explant) was obtained when 7-day-old cotyledons were cultured on WPM supplemented with 1.0 mg/L thidiazuron and 0.25 mg/L α-naphthalene acetic acid. The cultures were transferred to WPM augmented with 0.4 mg/L thidiazuron for shoot elongation and growth. On this medium, 100% of cultures responded with a mean number of 27.6 shoots. For callus induction, MS medium with 1.0 mg/L 2,4-dichlorophenoxyacetic acid and 0.5 mg/L N₆-benzylaminopurin was used. Shoot organogenesis was initiated on the same medium, and calli with minute shoots were transferred to MS medium fortified with 0.5 mg/L N₆-benzylaminopurin and 0.25 mg/L α-naphthalene acetic acid for highest shoot regeneration (100% cultures responded with a mean number of 26.5 shoots per explant). Maximum rooting frequency (82%) and number (20.8) were obtained on half-strength MS medium with 1.0 mg/L indole-3-butyric acid. The rooted plants were acclimatized and transferred to the field. The HPTLC and SCoT analysis revealed the phytochemical and clonal similarity between the in vitro propagated plants and mother plant.

CONCLUSIONS

In this study, it is confirmed that cotyledon is an excellent explant for direct and indirect shoot organogenesis in T. siliquosa. For direct shoot induction WPM and indirect organogenesis, MS medium was found to give better response. The true-to-type nature of in vitro-derived plants were confirmed by phytochemical and SCoT analysis. The protocol described here could be used for the large-scale propagation of elite clones of T. siliquosa.

Tissue Culture in Ornamentals: Cultivation Factors, Propagation Techniques, and Its Application

Ornamentals come in a variety of shapes, sizes, and colors to suit a wide range of climates, landscapes, and gardening needs. Compared to demand, a shortage of plant materials and diversity force the search for solutions for their constant acquisition and improvement to increase their commercial value, respectively. In vitro cultures are a suitable solution to meet expectations using callus culture, somatic embryogenesis, protoplast culture, and the organogenesis of protocorm-like bodies; many of these techniques are commercially practiced. Factors such as culture media, explants, carbohydrates, plant growth regulators, and light are associated with the success of in vitro propagation. Techniques, especially embryo rescue and somatic hybridization, are widely used to improve ornamentals. The development of synthetic seed allows season-independent seed production and preservation in the long term. Despite the advantages of propagation and the improvement of ornamentals, many barriers still need to be resolved. In contrast to propagation and crop developmental studies, there is also a high scope for molecular studies, especially epigenetic changes caused by plant tissue culture of ornamentals. In this review, we have accumulated and discussed an overall update on cultivation factors, propagation techniques in ornamental plant tissue culture, in vitro plant improvement techniques, and future perspectives.

In Vitro Culture of Eremurus spectabilis (Liliaceae), a Rare Ornamental and Medicinal Plant, through Root Explants

Eremurus spectabilis M. Bieb, a perennial herbaceous wild species, is commonly used in the horticultural, ornamental, and pharmaceutical markets. Studies on the tissue culture systems for this species would be beneficial for mass multiplication as well as for future breeding programs. An in vitro propagation technique was established here using tuberous root explants as unique and responsive starting materials for culture initiation. The proliferated calli were sub-cultured on shoot proliferation media and regenerated microshoots were assessed. The shoot proliferation rate, leaf number, leaf length, and chlorophyll and carotenoid contents were recorded. The highest callus induction per explant (76.67%), callus dry weight (10.25 mg), callus firmness ratio (3.97), and callus color intensity ratio (2.83) were observed in explants inoculated on Murashige and Skoog (MS) medium supplemented with 10.0 mgL−1 6-benzylaminopurine (BAP). The highest shoot proliferation rates were obtained when calli were sub-cultured on MS or Schenk and Hildebrandt (SH) basal media supplemented with 2.0 mgL−1 BAP. The half-strength MS medium fortified with 4.0% sucrose + 2.0 mgL−1 indole butyric acid (IBA) + 200 mgL−1 activated charcoal was a superior combination for root emergence and rooting parameters. Regenerated plantlets were then successfully adapted to ex vitro conditions. The reported protocol can be exploited at a commercial scale following minor modification, or could be beneficial in the production of secondary metabolites in bioreactors where callus is required as fresh plant material.

Microbulb and plantlet formation of a native bulbous flower, Lilium monodelphum M. Bieb, var. Armenum, through tissue culture propagation

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To prevent the loss of some natural species by the balance deteriorating due to environmental problems has come into prominence in recent years.

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While, The Life animated by plants that each of the unique whose power is contains many species with beautiful appearance and nice smells, also, because some species contain aromatic and other useful substances, they are of interest in the perfume and medicine industries.

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There are present studies that make a point of protection and commercially multiplicate of natural plant species that is belonging to Liliaceae. In the formation of in vitro microbulbs and adventitious buds from Lilium species, it is important to determine the optimum paclobutrazol and thidiazuron amount to be added to the medium.

The plant Lilium monadelphum M. Bieb. var. armenum (Mıscz. Ex Grossh) Davis et Henderson recognized as the caucasian lily grows in the Eastern Black Sea Region and is a perennial bulbous species belonging to the Liliaceae family. Its flowers, bulbs, and volatile oils are used in the perfume industry, as a folk medicine to treat eczema and abscess therapy, and as a tranquilizer among regional people respectively. Hence, it is commonly collected from the wild and could become endangered. In this study, we explored the optimal hormone treatment for efficient and rapid induction and production of this species in tissue culture. Explants taken from bulbs were cultured in Murashige and Skoog medium (MS medium, 1962) and modified with TDZ (thidiazuran) (0.5; 1.0; 2.0; 3.0; 5.0 mg/L), after which adventitious buds used for explants during the second stage were subcultured 4 different media supplemented with different concentrations of PAC (paclobutrazol) (0.1; 0.5; 1.0; 2.0 mg/L) to induce microbulbs formation. Microbulbs were cultured in a rooting medium containing IBA (0.5;1.0 mg/L). The highest bud regeneration was observed in medium containing 3.0 mg/L TDZ, 0.25 mg/L NAA and 0.1 mg/L GA3; the highest microbulb formation was observed in medium containing 2.0 mg/L PAC, 0.2 mg/L NAA, and 0.1 mg/L GA3. Besides, plant development from the microbulb was successful for roots in a medium containing 0.5 mg/I IBA and all of the plantlets obtained in tissue culture survived when transferred to the soil.

Genetic homogeneity revealed in micropropagated Bauhinia racemosa Lam. using gene targeted markers CBDP and SCoT

Two gene targeted markers i.e. CAAT box-derived polymorphism (CBDP) and start codon targeted (SCoT) polymorphism were applied to analyze the genetic stability of in vitro propagated plants of Bauhinia racemosa Lam. multiplied by enhanced axillary shoot proliferation of mature tree derived nodal explant. Nine randomly selected micropropagated plants of 1 year age were subjected to molecular analysis. The isolated genomic DNA samples were subjected to PCR amplification with a total of 61 primers (25 CBDP and 36 SCoT) out of which 39 primers (21 CBDP and 18 SCoT) produced scorable amplicons. A total of 97 and 88 clear, distinct and reproducible amplicons were produced by CBDP and SCoT primers, respectively. The monomorphic banding pattern obtained through all the tested primers corroborated the true to type nature of in vitro propagated plants of B. racemosa.

Effects of Growth Regulators and Gelling Agents on Ex Vitro Rooting of Raspberry

Successful acclimatization and ex vitro rooting are among the key factors reducing the cost of micropropagated plants. We compared the survival of seven Russian cultivars of raspberry (Rubus idaeus) after rooting in vitro and ex vitro. Rooted shoots adapted to nonsterile conditions much better than nonrooted ones, with survival rates of 81%–98% versus 43%–76%, respectively. We studied the effects of different combinations of plant-growth regulators and gelling agents added to a proliferation medium on ex vitro rooting of primocane-fruiting raspberry cultivar “Atlant”. Reducing the agar concentration from 8 to 6.5 g/L increased the multiplication rate, but caused shoot hyperhydricity. The highest survival rate (97.2%) was observed for shoots grown in a medium containing 0.2 and 0.1 mg/L IBA, and gelled with 5 g/L agar and 0.2 g/L Phytagel. The microshoot height at the multiplication stage did not correlate with the plant growth during acclimatization. The obtained results can be used in the commercial micropropagation of the raspberry.