The Role of Growth Regulators in The Multiplication of Stevia Rebaudiana Bertoni Shoot and Callus Induction in Vitro

The research was conducted to investigate the effect of plant growth regulators on the vegetative multiplication of the Stevia plant shoot and the induction of callus from it. The results indicated that the interaction between 2.0 mg. L-1 BA with 0.5 mg. L -1 Kin gave the highest rate number of shoot with 6.32 branches and the highest average of leaves number Were 9.60 leaves compared to the lowest average for the number of shoot and leaves Were 1.40 shoot and 3.80 leaves respectively. As for the length of the shoot, the interaction between (1.0 mg. L-1 BA and 0.5 mg. L-1 Kin) gave the highest average shoot length 4.31 cm compared to the control which gave 2.20 cm. in connection with the callus induction, the concentration 3 mg. L-1 of NAA gave the highest percentage of callus induction from leaves 100%, and the lowest mean of days that for callus initiation was 9 days compared to the control which reached to 20 days. As for the wet and dry weights of callus tissue, the interaction between 2.0 mg. L-1 NAA and 0.5 mg. L -1BA gave the highest wet weight rate 3.68 g and the average dry weight was 0.31 g compared to the control which gave the lowest rate 0.95 g, 0.08 g respectively.

EVALUATION OF BIOMASS AND VEGETATIVE PROPAGATION OF SPILANTHES OLERACEA JACQ. (Asteraceae)

Spilanthes oleracea Jacq. is an herbaceous plant whose scientific literature attributes among others, anti-malarial and anti-bilharzia properties. These virtues justify the placing on the market of drugs based on the plant.Our study consisted on the one hand to evaluate the biomass of the plant on a soil of dune amended and on soil of unamended dune and to test its vegetative multiplication by transplanting, cuttings and layering.The results show that the growth of the species is greater on dune soil amended with an average biomass of 106.06 g compared to 71.06 g for un-amended soil plants. The transplanting of the plants and the layering were techniques that made it possible to multiply the plants.Spilanthes oleracea Jacq. can be produced using this agronomic data.

Alternative biotechnological approaches for propagation of Helichrysum italicum (Roth) G. Don (Asteraceae)

Biotechnology uses diverse approaches for plant propagation, among them in vitro micropropagation and hydroponics, based on the plant's capacity for vegetative multiplication. Nowadays, the market demand of Helichrysum italicum is increasing for its valuable essential oils; however, seed quality and crops’ growth are variable. The aim of this study was to test different approaches for rapid multiplication of cultivars. Seeds and stem tips were used as initial material for in vitro cultivation (MS medium), and cuttings - for hydroponic propagation (Cutting board system, GHE) in culture rooms under 16/8 h photoperiod and 23±2°C temperature. In vitro cultures initiation was hampered by high microbial contamination: 55.8% of the seeds survived, and almost all leaf explants dropped out due to fungi or necrosis. Seed germination was stimulated with 0.1% GA3 and increased up to 24.4%, while a fungi-free stem-tips culture was obtained on medium containing antibiotic. Subcultivation was tested on media supplemented with different plant growth regulators, and 6.4 new shoots per explant were obtained on the best medium containing 2 mg/l BAP and 0.2 mg/l NAA, for 8 weeks. Plants cultivated on MS control medium rooted spontaneously and some of them were ex vitro adapted to phytotron and then to а greenhouse. On the hydroponic system, 77.8% of the cuttings rooted; 76.2% of which were transferred to soil mixture, and 81.3% of the potted plants successfully adapted to greenhouse conditions. Vegetative rapid propagation of valuable H. italicum cultivars was proved to be feasible by both in vitro and hydroponic multiplication for a 6-month period.

Establishment of Technological Stages for Obtaining Some Grafted Tomato Seedlings (Dutch Scion × Romanian Rootstocks)

The tomatoes are valuable vegetables, with highest share in Romanian crops from protected spaces. The grafting is a vegetative multiplication method that induces or improves some qualities of the plants (vigor, resistance to soil diseases and pests, resistance to abiotic factors, quantity and quality of fruit production). The research aim has been to establish the technological stages for producing of Dutch scion and Romanian rootstock seedlings from Solanum lycopersicum L. species, to obtain some compatible phenotypes for grafting. This research has been conducted in a greenhouse of the Horting Institute Bucharest. The experience was carried out on a tomato cultivar collection consisting from a Dutch scion (‘Abellus’ F1 hybrid) and three Romanian rootstocks (‘L542’, ‘L543’, ‘L544’). The scion and rootstock diameters have been correlated for manual grafting, cutting at 45 degrees and using the method of splice in silicone tube. The technological stages for obtaining grafted tomatoes have been established for the researched genotypes. These tomato combinations have been compatible for vegetable crops in protected spaces in the south area of Romania.

Induction of Indirect Somatic Embryogenesis on Embryonic Axis of TRI2025 Tea Clone

Tea (Camellia sinensis L.) is classified as cross-pollinated crop and vegetative multiplication becomes commercially the main method of propagation with some limitations such as high heterogeneity and poor in survival rate and also in rooting. A proven tissue culture method, somatic embryogenesis, is the only challenging way to meet the needs of tea seedlings in large quantities. The study was conducted with TRI2025 tea clone selected from Polyclonal garden of PT. Pagilaran (Batang, Central Java). The explants were cultured on MS media supplemented with four concentrations of 2,4-D (0, 1, 2, and 5 mg L-1) in two incubation conditions; dark and light. The results showed the only concentration of 2,4-D that can induce somatic embryo was 2 mg L-1 2,4-D in light condition and its percentage was about 5%. Other concentrations of 2,4-D that given for treatments both in two conditions will not induce somatic embryo. This study needs more improvements for getting powerful and efficient of method to get somatic embryo-derived plant and also for futher successful genetic engineering of tea biotechnology.

Siddhast Technique: a new vegetative multiplication and water conservative technique for Jatropha curcas

Energy security is one of the prime concerns of any developing/developed nation and India ranks sixth in the world in terms of energy demand. The Indian economy is expected to grow at a rate of over 6 per cent per annum. The petroleum imports are expected to rise to 166 MT by 2019 and 622 MT by 2047, hence there is a growing need for energy security. Jatropha curcas has the potential to become a significant source of renewable energy if improved varieties are developed which can achieve its potential in terms of oil yield per hectare in marginal land. For vegetative multiplication, we have successfully carried out air layering in Jatropha curcas through siddhast technique, where a stem is induced to form roots using Rooter Strand while branch is still intact on the parent plant. Virtually no extra water is required to be given to the parent tree to produce a rooted plant. Here, we examined the competency of eight Rooter Strands vis-à-vis two conventional techniques of air layering i.e. tourniquet and gootee. Results showed that time for root initiation did not vary with treatments. In branches tied with Rooter Strand rooting started in minimum 3 weeks; the average root initiation period with Rooter strand was 4.56-6.66 weeks of installation. However, both conventional techniques T9 and T10 required 8.05 weeks and 6.40 weeks, respectively, to start root initiation. Significantly better rooting observed as compared with tourniquet technique and highest 100 per cent rooting was recorded in Rooter Strand-2, 31 and 41 along with control. Significant difference also observed among all the treatments representing Rooter Strand showed usually 83 per cent or higher for survival percent. This technique is very easy and does not require much skill. This technique has the advantages of air layering i.e. less need for physical inputs (water, electricity, infrastructure, etc). It reduces water consumption up to 90 per cent and electricity 100 per cent as compared to tissue culture. Thus, this technique is very conservative from cuttings and much faster than normal procedure of air layering for producing true-to-type plant material and can be adopted for multiplication of superior varieties of this species for their large-scale deployment for biodiesel production to ensure sustainable development with least water requirement.

Evaluation of the Efficiency of Opuntia ficus-indica Cladode Cuttings for Vegetative Multiplication

In Tunisia, Opuntia ficus-indica (L.) Mill., occupying many hundreds of thousand hectares, constitutes a future plant as a fruit tree, mainly due to its edible fruit and vegetal mass used as food. The continuously increasing demand for young plants for the extension of its cultivation requires the research of rapid, efficiency and economic methods ensuring conformity multiplication. With aim to a large production of plant material, a rapid in situ propagation method of the prickly pear cactus was developed. Varied portions of Opuntia ficus-indica cladodes harvested in spring or in autumn, planted horizontally or vertically were used in order to optimize rhizogenesis and secondary cladode initiation rates. Half, quarter and the tenth of cladode cuttings harvested and planted in spring vertically and in normal polarity show very interesting results concerning rhizogenesis and caulogenesis. Those portions of cladodes demonstrated the best results, vertically planted in normal polarity and 100% of rooting was observed on right ones. The number of roots was the highest on basal right tenth cuttings (80). Contrariwise, the percentage of secondary cladodes initiated was the highest on apical right cuttings (70 and 74%) and the longest roots were initiated on the two basal tenth cuttings, left and right ones (13 and 14 cm). This fragmentation represents a substantially gain of material and time especially for large cultivated surfaces of Opuntia ficus-indica. Reducing the cladode cutting size, do not reduce its rhizogenesis and caulogenesis potentialities.