ECONOMICAL STUDY OF IN VIVO AND IN VITRO PROPAGATION OF RUSSELIA EQUISETIFORMIS

This experimental trial was performed throughout two successive seasons (2015-2016) and (2016-2017) at the nursery of Horticulture Research Institute, Agricultural Research Center, Giza, Egypt. Intended to find out the effect of the individual and combined effects of different growing media with different types of propagation on morphological traits and some chemical constituents of Russelia equisetiformis Schlecht. & Cham plant. Accordingly, on September 1^st, in the two seasons, different plant parts of the whole plant (tip and mid cutting of 10-12 cm length, besides divisions containing foliage and root parts were planted in 10 cm plastic pots (one plant/pot) for every growing media used. The plants were left to grow under open field conditions. The layout of the experiment was a factorial experiment in randomized complete block design (RCBD) with three replicates (2 growing media × 3 types of propagation). The results emphasized that the mixture of sand + 15% compost proved its mastery in improving vegetative growth parameters (plant height, number of branches/plant, fresh and dry weight of shoots). Besides, it was the best mixture used for raising fresh and dry weight of roots. Also, such mixture was superior in increasing survival rate %. Meantime, it raised pigments content in the leaves (chlorophyll a, b, total chlorophylls and carotenoids). Results showed also the prevalence of using division parts in propagation, which to improvise the above mentioned morphological traits studied in both seasons. Meanwhile, using tip cuttings in propagation proved its mastery in raising survival rate %, whereas using mid cuttings was the best in rising chlorophyll (b) in the leaves in both seasons. Also, using either mid cuttings or division parts was the best in raising total chlorophyll in the leaves. Using tip cuttings or division parts was the best in increasing carotenoids content in leaves in the first season, whereas using either mid cuttings or division plants was the best for raising the same content in the second one.
From the aforementioned results, it could be recommended to use division parts in propagation and using the mixture of sand + compost 15% in pots for obtaining the best characters of Russelia equisetiformis plant under local conditions. Moreover, a protocol of micropropagation of Russelia equisetiformis was established using nodal explants taken from the main shoot and lateral branches. Explants were sterilized using 0.1% (w/v) mercuric chloride for 7 and 10 min for the main shoot and lateral branches explants, respectively as 100% of explants were surface decontaminated, survived and stimulated to form shoots. Data of the multiplication stage showed that the highest survival percentages were recorded when explants were cultured on MS medium supplemented with BAP at 0.25 or 0.50 mg/l or kin at 0.25 mg/l which recorded 97.22, 93.06 and 94.44%, respectively. The significantly highest number of the formed shootlets/explant (3.05) was obtained when medium was supplemented with 0.75 mg/l BAP during the third subculture. The significantly highest value of shootlet length (4.72 cm) was recorded when 0.25 mg/l of kin was used during the second subculture. The most suitable treatment for rooting stage was ¾ MS strength which recorded 100% rooting, 8.86 roots/plantlet with 4.56 cm root length. The in vitro propagated plantlets (microshoots with well-developed roots) were hardened in greenhouse with 82% survival rate.
From the above mentioned results, it could be concluded that using tissue culture in propagation is considered the best economic way for the propagation of theRusselia equisetiformis plant comparing with that gained from the other propagation method used. Additionally, it could be mentioned that the profitability rate % of the production by the way of tissue culture method only 780.73% comparing with 338.2% terminal cutting.