Differing In Vitro Rooting and Flowering Responses of the Persian Violet to Low and High UV-C Irradiation

Persian violet flowers are considered esthetically attractive, leading to the high economic value of this plant. Plant breeding is fundamental to crop improvement, and the induction of mutation by tissue culture technology in combination with irradiation has been beneficially applied to generate plants with novel desirable characteristics. In this research, single or double rounds of UV-C irradiations were carried out on plant tissue cultures to initiate the in vitro rooting and mutation of Persian violets. It was found that single low-intensity UV-C exposure, when applied to Persian violet microshoots for 4 h, could induce the maximum number of roots and the highest root length without the use of a plant growth regulator. Overall, the single and double UV-C irradiation of Persian violet microshoots led to 44 different types of Persian violet flower mutations. Under single high-intensity UV-C irradiation for 6 h, up to nine petals were initiated, whereas single low-intensity UV-C irradiation did not influence the morphological variation of Persian violet flowers. Thus, Persian violet microshoots respond differently in terms of in vitro rooting and flowering depending on the UV-C intensity and exposure duration. These outcomes may be applied to micropropagation and in vitro plant breeding.

Effect of Light on Rhizogenesis of Forest Berry Plants during Clonal Micropropagation

Introduction. Forest berry plants are popular on the food market and in pharmacy for their high nutritional and medicinal value. Plantations of forest berry plants can proliferate on unused lands, including depleted peatlands. Clonal micropropagation is the most effective method for obtaining large quantities of high quality planting material. Light-emitting diodes are highly effective for clonal micropropagation. The research objective was to study the effect of different spectral ranges on the process of root formation of forest berry plants in vitro. Study objects and methods. The research featured regenerant plants of half-highbush blueberry, arctic bramble, American cranberry, European cranberry, lingonberry, and Kamchatka bilberry of different cultivars. A set of experiments made it possible to study the effect of lighting type on the growth and development of the root system of forest berry plants in vitro using white fluorescent lamps, white spectrum LED lamps, and LED lamps with a combination of white, red, and blue spectra at the in vitro rooting stage of clonal micropropagation. Results and its discussion. The largest number (3.4–14.6 pcs.) and the maximum total length (10.0–156.9 cm) of roots were observed under LED lamps with a combination of white, red, and blue spectra. The effect was by 1.1–2.8 and 2.0–4.5 times higher than in the case of white-spectrum LED lamps, and by 2.3–7.0 and 3.3–14.9 times than in the case of fluorescent lamps. Variety and shape proved to have no significant effect on biometric indicators. Conclusion. LED lamps had a positive effect on the process of rhizogenesis of forest berry plants during clonal micropropagation. They appeared to be more effective than fluorescent lamps. The combination of white, blue, and red spectra increased the biometric parameters of plants at the stage of in vitro rooting.

In vitro rooting of promising Lonicera caeruleae L. cultivars

The work is devoted to the improvement of the in vitro rooting technique of valuable Lonicera caerulea L. cultivars. The influence of different types of auxins and iron sources was determined at the stage of rhizogenesis. The use of indolylbutyric acid at a concentration of 1.0 mg/l was effective for the rooting of the cultivars Solovey and Yugana: the rooting rate was 60% and 99%, respectively. When using indoleacetic and indolylbutyric acids no significant differences were found in the percentage of rooting rates in the cultivars Gzhelka, Dlinnoplodnaya, Knyaginya and Lenya. It was found that 200 mg/l of iron chelate (Fe(III)-EDDHA) and 0.5 mg/l of indoleacetic acid in the nutrient medium had a positive effect on the dynamics of root formation of most honeysuckle cultivars. It was preferable to use a nutrient medium with the addition of iron chelate Fe(III)-EDTA at a concentration of 73.4 mg / l for the cultivar Yugana (rooting rate was 76%). Keywords: LONICERA CAERULEA, CULTIVARS, IN VITRO, RHIZOGENESIS, AUXINS, SOURCES OF IRON

Improved in vitro rooting and acclimatization of “Violetta” Artichoke and “Green Globe” Artichoke

Artichoke (Cynara scolymus L.), a medicinal plant with high economic value, contains high levels of phenolic compounds; especially cynarine, which plays an important role in preventing cancer, cardiovascular disease, osteoporosis, diabetes and neurodegeneration, etc. Currently, Artichoke micropropagation has achieved some success; however, the rooting efficiency and plantlet quality are still limited. In this study, improving the quality of Artichoke plantlet related to the shoot quality and suitable substrates in in vitro rooting stage was studied on “Violetta” Artichoke (VA) and “Green Globe” Artichoke (GA). The results showed that shoots (1.5 cm) cultured on MS medium supplemented 0.5 mg/L KIN were most suitable to shoot multiplication of VA with the number of shoots/explant (3.67 shoots), number of shoots ≥ 2 cm (3 shoots); while, 1.0 mg/L BA was suitable to shoot multiplication of GA (5.33 shoots; 5.00 shoots; respectively) after 4 weeks of culture. Besides, the in vitro rooting was improved using 8 g/L commercial agar for VA; meanwwhile, 3 g/L gelrite for GA. In addition, the nylon bag culture system (120 mm × 250 mm) has potential in plantlet production (15 plants/bag) and can be applied for large scale micropropagation. In addition, VA and GA plantlets derived from in vitro culture gave the good acclimatization, growth and development after 8, 12 and 20 weeks cultivating at the green house conditions.

Micropropagation of Paphiopedilum x Dalatense

Paphiopedilum x dalatense is a beautiful orchid species with large flowers in variable colors and leaves covered with stripes and beautiful unseen mosaic spots. Recently, many people exploit this species, causing it becomes very rare. In this study, we studied the effects of various organic matter: potato, banana and tryptone, yeast powder, peptone on the growth and development of P. dalatense shoots as well as the effects of NAA and humic acid on in vitro rooting of this orchid were investigated. The research results showed that MS medium supplemented with 100 g/L banana in combination with 100 g/L potato (5,4 shoots/sample, 18,8 mm/shoot, 4,5 leaves/shoot, and shoots survival rate of 100%) or MS medium supplemented with 1 g/L peptone (4,19 shoots/sample, 15 mm/shoot, 4 leaves/bud, and 92% of shoots survival rate) were the best response for the shoot formation and development. In addition, the half strength MS culture medium supplemented with 1 mg/L NAA (5,2 leaves/sample, 4,6 roots/buds, 3,56 cm/root, and 100% rate for rooting) was the suitable medium for the in vitro rooting of P. dalatense. Being cultured on half strength MS medium supplemented with 2 mg/L humic acid, the rooting rate reached 100% with the greatest root number and the longest root (5 roots/shoots, 5,5 cm/root). The obtained results on the in vitro propagation on this orchid helps contribute to the conservation and increases the genotic pool of this precious wild orchid species, as well as the rapid multiplication of healthy plantlets serving the commercialization of precious orchid species.

Effect of pH, Sucrose Concentrations and Medium States on in vitro Root-ing of Pineapple (Ananas comosus (L) Merr) cv Queen

The effect of medium states (liquid, semi solid, solid), pH (5.0, 5.5, 6.0, 6.5) and sucrose concentrations (10, 20, 30, 40 g/l) on in vitro rooting of pineapple cultured in full strength MS enriched with IBA at 0.5 mg/l were investigated. According to average overall sucrose concentrations, overall pH adjustments, and at each combination of equal sucrose and pH, liquid medium was always super than solid and semisolid. The tallest plantlets (66 to 71 mm) obtained in liquid medium enriched with sucrose at 10 and 20 g/l both adjusted to pH 6.0; sucrose at 20 g/l and adjusted to pH 6.5 and sucrose at 30 g/l and adjusted to pH 5.0. All of the above combinations except sucrose at 20 and pH 6.0 resulted in 100% rooting. Sucrose at 30 g/l and pH 5.0 resulted in two times more (11 roots per shoot) and three times longer roots (39 mm) than the other treatments (5 roots each about 14 mm long). Each rooting parameter had different optimum combinations of medium state, sucrose and pH adjustment. For any parameter, proper pH adjustment could reduce the optimal sucrose enrichment from 30 to 20 and even to 10 g/l. Hence, pH adjustment is suggested as an important approach for reduction of in vitro rooting medium cost.

Effect of Explants Length and Density on in Vitro Rooting of Pineapple Ananas Comosus L Merr

Pineapple explants of different length (5, 10, 15, and 20 mm long) were cultured at different densities (one, two, three, four, and five explants per culture) on full strength, agar solidified MS medium supplemented with sucrose at 30 g/l and IBA at 2.0 mg/l for 60 days. The rooting ability (rooting %, root number, and length) of the explants were not affected by the explants' length and explants' densities per culture. Irrespective of length and densities, 82 % of the explants rooted and produced 4.1 roots each 17.7 mm long. Moreover, overall explants lengths, plantlet height was not affected by explants density and were about 50.5 mm tall. On contrary, overall density, explant of different lengths developed into plantlets of significantly different height. Plantlets' height increased from 39.2 to 49.6; 55.9 and 57.4 mm as the explants length increased from 5 to 10; 15 and 20 mm respectively. Keywords: Pineapple; Ananas comosus; Explants length; Explants density