In Vitro Germination and Flowering of Dendrobium capra J.J. Smith, An Endemic Orchid of Java

Dendrobium capra is an Indonesian endemic orchid species that live in Java. It grows on low altitude with warm climate. D. capra has beautiful small yellow greenish flower that grow in raceme inflorescence. This orchid faces a threat in its natural habitat due to having a long life cycle and a forestry main commodity as a main host thus categorized as Appendix II on CITES list. To address that problem, ex situ conservation approach using in vitro culture method is necessary. Germination enhancement effort using complex organic substances found that 200 ml/l tomato extract gave best germination result. Analysis on D. capra plantlet growth also showed that MS medium produced better plantlet size than NP, VW and KC medium. Supplementing medium with a combination of NAA and TDZ has also successfully induced early flowering within 11 month of culture period. This information is important to achieve successful in vitro culture of D. capra for various purposes.

Plantlet Regeneration and Multiple Shoot Induction from Protocorm-Like Bodies (PLBs) of Medicinal Orchid Species, Dendrobium crumenatum Sw.

To investigate the suitable medium for in vitro shoot regeneration and plantlet growth of Dendrobium crumenatum Sw., individual protocorm-like bodies (PLBs) (about 4 - 5 mm in diameter) of Dendrobium crumenatum Sw. derived from MS medium supplemented with 0.5 mg/L TDZ for 60 days of culture were cultured on 6 culture media; Murashige and Skoog (MS) medium, MS medium supplemented with 15 % (v/v) CW, MS medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC, Vacin and Went (VW) medium, VW medium supplemented with 15 % (v/v) CW, VW medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC. After 4 months of culture, MS medium containing 15 % coconut water (CW) gave the highest percentage of shooting and number of shoots per explant of 96.0 and 9.5, respectively with a significant difference from other media. The addition of 0.2 % (w/v) activated charcoal (AC) significantly increased the number of leaves and roots. PLBs developed into complete plantlets. MS medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC and VW medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC gave the highest number of roots per plantlet and root length at 5.3 roots and 34.9 mm, respectively. After the transfer of rooted shoots to the greenhouse, 95 % of the regenerated plantlets survived and grew vigorously. Plantlets grown in vitro were successfully acclimatized in the greenhouse and showed normal development.

In Vitro Propagation of Resurrection Plant Selaginella pulvinata Using Frond Tips as Explants

The resurrection plant Selaginella pulvinata (Hook. & Grev.) Maxim is used as an ornamental and medicinal plant. It is also a good candidate for exploring the desiccation tolerance of resurrection plants. However, there is not an efficient propagation method for S. pulvinata. In the present study, we evaluated the establishment of in vitro propagation of S. pulvinata using frond tips as explants. The original shoot induction, adventitious shoot proliferation and plantlet growth media, and substrate type of plantlet acclimatization were investigated. The highest induction rate of original shoots (61.77 ± 5.17%) was obtained on half-strength (1/2) MS medium supplemented with 0.1 mg·L−1 N6-benzylaminopurine (BAP). The 1/2 MS with 1.0 mg·L−1 BAP was the most effective medium for the adventitious shoot proliferation. The quarter-strength (1/4) MS containing 0.1% (w/v) active charcoal (AC) was optimum for plantlets proliferated from adventitious shoots and plantlet growth. Approximately 98 plantlets could be obtained from one single original shoot via one-time shoot proliferation cultivation and plantlet cultivation. The acclimated plants on a 5:1 (v/v) mixture of peat and perlite had the highest survival rate (92.13 ± 1.67%). The acclimated plants maintained excellent resurrection ability.

Peach palm plantlet growth in different culture media in a temporary immersion system

ABSTRACT: Peach palm is a domesticated palm commercially important for the production of fruits and hearts of palm. Somatic embryogenesis, an effective technique for mass propagation, was successfully established for this species. Furthermore, a temporary immersion system improved plant regeneration. However, production can be further improved by understanding the peach palm’s growth dynamic and modifications of culture media. The aims of this study were to evaluate the growth of plantlets cultured in different culture media in a temporary immersion system and to correlate the results with nutrient uptake during the growth period. Somatic embryo-derived young plantlets approximately 1 cm in length were cultivated for 12 weeks in a twin flask system containing MS, Y3 or N6 salts, Morel and Wetmore vitamins and 3% sucrose, with a monthly medium refreshment. Growth was measured and mineral analysis of the plantlets was carried out after 12 weeks of culture. The Y3 and MS salts were the most appropriate for the plant growth. Number of roots was 52.52% higher and the root size was 40.42% between the N6 and MS medium and the root number in Y3 medium was 37.74% greater than in MS medium, which is important for post acclimatization survival. K and Na are important elements for peach palm. N is not required at such a high concentration as in Murashige and Skoog formulation. The Chu (N6) medium did not generate high quality plantlets, possibly due to the absence of some micronutrients, like Mo, Cu and Co.

Growth of pineapple plantlets during acclimatisation can be monitored through automated image analysis of the canopy

Pineapple is an economically important tropical fruit crop, but the lack of adequate planting material limits its productivity. A range of micropropagation protocols has been developed over the years to address this shortfall. Still, the final stage of micropropagation, i.e. acclimatisation, remains a challenge as pineapple plantlets grow very slowly. Several studies have been conducted focusing on this phase and attempting to improve plantlet growth and establishment, which requires tools for the non-destructive evaluation of growth during acclimatisation. This report describes the use of semi-automated and automated image analysis to quantify canopy growth of pineapple plantlets, during five months of acclimatisation. The canopy area progressively increased during acclimatisation, particularly after 90 days. Regression analyses were performed to determine the relationships between the automated image analysis and morphological indicators of growth. The mathematical relationships between estimations of the canopy area and the fresh and dry weights of intact plantlets, middle-aged leaves (D leaves) and roots showed determination coefficients (R2) between 0.84 and 0.92. We propose an appropriate tool for the simple, objective and non-destructive evaluation of pineapple plantlets growth, which can be generally applied for plant phenotyping, to reduce costs and develop streamlined pipelines for the assessment of plant growth.

Growth Evaluation of Banana cv. Barangan as the Effect of Trichoderma sp. and Covering Types during Acclimatization Process

<p>Acclimatization is one of the important processes in banana micro propagation before plantlets/planting materials are ready to be cultivated in the field. <em>Trichoderma </em>sp. are well known as plant promoter fungi that can promote plant growth and increase survival rate of plantlets. The study was arranged in a Completely Randomized Factorial Design with two factors and four replications. The first factors was covering type i.e. 1) individual covering and 2) mass covering. The second factor was the proportion of <em>Trichoderma</em> addition into manure, namely A) manure without the addition of <em>Trichoderma </em>sp<em>.</em> (control), B) <em>Trichoderma</em> sp<em>.</em> : manure =<em> </em>1 : 400 (w/w), C) <em>Trichoderma </em>sp<em>.</em> : manure = 1 : 800 (w/w) and D) <em>Trichoderma </em>sp<em>.</em> : manure = 1 : 1,200 (w/w). The purpose of this study was to investigate the effect of <em>Trichoderma</em> sp<em>. </em>applications and covering types in the growth of banana plantlets cv. Barangan during the acclimatization process. The results showed that the best treatment to induce plantlet growth during the acclimatization process was the addition of <em>Trichoderma </em>sp.: manure with 1 : 400 (w/w) proportion and individual covering. The combination of <em>Trichoderma </em>sp<em>.</em> : manure with 1 : 400 (w/w) proportion and individual covering produced plant height and leaf length 8.5 cm and 4.4 cm, respectively, compared to the treatment without <em>Trichoderma </em>sp<em>. </em>addition that produced plantlets with 6.6 cm height and 3.4 cm leaf length. No significant interaction was shown between <em>Trichoderma </em>sp. proportions and covering types on leaf width, the number of leaves and root length parameters.</p>

Pennisetum sinese: A Potential Phytoremediation Plant for Chromium Deletion from Soil

Chromium is one of the major pollutants in water and soil. Thus, it is urgent to develop a new method for chromium removal from the environment. Phytoremediation is a promising approach for heavy metal pollution recovery. As a perennial giant grass with a fast growth rate, Pennisetum sinese has been widely used as livestock feed, mushroom culture medium and biomass energy raw material. Interestingly, we have found a high adsorption capacity of P. sinese for chromium. P. sinese was treated with different concentrations of chromium for 15 days. Results showed that P. sinese plantlets grew well under low concentrations (less than 500 μM) of chromium (VI). The plantlet growth was inhibited when treated with high concentrations of chromium (more than 1000 μM). Up to 150.99 and 979.03 mg·kg−1 DW of chromium accumulated in the aerial part and root, respectively, under a treatment of 2000 μM Cr. The bioaccumulation factor (BCF) of P. sinese varied from 10.87 to 17.56, and reached a maximum value at the concentration of 500 μM. The results indicated that P. sinese showed strong tolerance and high accumulation capability under Cr stress. Therefore, the chromium removal potential of P. sinese has a great application prospect in phytoremediation.

Control of Erigeron bonariensis with Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus Essential Oils

In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs against the noxious weed Erigeron bonariensis were evaluated in pre- and post-emergence assays in greenhouse conditions. The EOs were applied at 2, 4, and 8 µL/mL, with Fitoil used as emulsifier. In post-emergence, two ways of application were tested, irrigation and spraying. Several germination parameters (germination %, mean germination time, and synchrony of the germination process) were evaluated in pre-emergence tests, and the phytotoxicity level was assessed in post-emergence. In pre-emergence, all EOs significantly reduced seed germination as compared to the controls, ranking: T. capitata > E. camaldulensis > S. chamaecyparissus > M. piperita. The effectiveness of all EOs varied with the tested dose, always following the rank 2 μL < 4 μL < 8 μL, with T. capitata EO showing full effectiveness even at the lowest dose. In post-emergence, T. capitata was the most effective EO, inducing a rather complete inhibition of plantlet growth at the highest two doses. These EOs demonstrated to have good potential for the formulation of natural herbicides.