EFFECT OF PLANT GROWTH REGULATORS ON IN VITRO AND EX VITRO CONDITIONS ON PROPAGATION OF DIANTHUS CARYOPHLLUS L

: This study was carried out in the tissue culture Laboratory at University of Baghdad during 2017-2018 in order to evaluate the effect of plant growth regulators on the propagation of two cultivars of Dianthus (Sun charm White and Master) under Ex vitro conditions by cultivating the single nodes using the MS medium which involved with different concentrations of growth regulators The interaction treatment 1.0 mg /L BA + 0.2 mg /L NAA gave the highest response percent of bloom reached 100% for the red cultivar, and the treatment 1.5 mg / L BA + 0.2 mg / L gave the highest response percent to the white cultivar bloom reached 90%.In the multiplication stage, the highest branches number was obtained at 4.5 branches by the application of 2.0 mg / L BA + 0.2 and 0.4 mg /L IAA for the red cultivar, while the white variety gave the highest branches number obtained at the treatment 2.0 mg /L BA + 0.1 mg /L IAA, which gave 4.8 branches. In the experiment of rooting under Ex Vitro conditions, the results revealed that the concentration of 2 mg / L IBA gave the highest rooting ratio, number, and length of roots reaching 50%, 1.40 and 1.23 cm respectively for the red cultivar, while the white cultivar was given, 70%, 1.60 and 1.20 cm respectively, and the plants were adapted under greenhouse conditions.


Introduction
Dianthus caryophyllus belongs to Caryophyllaceae family, which is a perennial herbaceous plant. It was found as wild growth in the Medi-terranean, with a branching height of 50-60 cm, with opposite thick waxy striped leaves, and flowers of many colors and aromatics, the diameter of flowers may reach more than 10 cm. It is one of the most important crops of cut flowers in the world due to the beauty of flowers; considered as the best in coordination for the available qualities and colors in all seasons of the year [1]. The technique of plant tissue culture has been used in Dianthus's propagation, but this technology is affected by several factors; including related to the nutrition medium and the physiological factor of the plant, and the success percent varies from season to another and according to the nature and age. The increment or decrement of the ideal limit affects the response of the plant organs while they are grown in tissue culture [2].
Several successful attempts were carried out to propagate Dianthus by planting different plant organs in tissue culture. [3] mentioned the use of single nodes of the Dianthus plant gave a successful plant. [4] recorded the highest propagation of the of branches apical of the Dianthus plant when planted on the medium of MS which equipped with 3 mg / L BA reached 7 branches / plant organs and in percent of rooting peaked at100% when planting on the medium of MS with a quarter of the strength of the concentration of minerals (0.1 mg / L IBA). [4] were recorded a number of branches of the white Dianthus plant Jeanne Dionis Blano reached 30 branch/ plant of the nodes cultivation. The research aims to propagate the Dianthus plant and evaluate the response of the branches that resulting from the propagation of roots in Vitro and under the conditions Ex Vitro in the field.

Materials and Methods
The study was carried out at University of Baghdad during 2017-2018. The plant parts with the same nodes number were taken from the two cultivars, the white Dianthus (Sun charm white) and the red Dianthus (Master) 3cm from growing parents in the lath house that be-longs to the Plant Protection Research Center, Abu Gharib.
The plant parts were transferred to the laboratory and kept under running water for 15 minutes, after washing with water and liquid soap to get rid of dust and suspended matter, then, all the leaves were re-moved and sterilized with a solution of Clorox 6% and a concentration of 3% (volume / volume) for 8 minutes with the addition of the diffuser, thereafter washed three times with sterile distilled water for 5 minutes each time after cutting the vegetable parts to a length of 1 cm and planted on the medium of MS equipped with concentrations of 0, 0.5, 1.0,1.5 mg/L BA and NAA for developmental phase, one branch was planted in each tube and there were 10 replications per treatment and measurements were taken 6 weeks after planting.
The concentrations BA and IAA were applied for doubling stage with one branch per tube in total of ten tubes. The data was recorded after 6 weeks of cultivation. The cultivated parts were incubated in all stages of propagation at a temperature of 25 ± 2 and under light intensity of 1000 lux for 16 hours of light. The branches resulting from the doubling phase were planted in two rooting experiments; the first was in vitro, the green branches resulting from the doubling were cultivated on the medium of MS with full strength and equipped with concentrations of 0.0, 0.5, 1.0, 1.5 mg/L IBA [5]. The second was ex vitro by rooting the branches resulting from the cultivation experiment by putting the ends of the branches in IBA for 5 minutes and then planted directly in the culture medium consisting of sand and peat moss in a 1: 1 ratio taking into account their coverage until completion Rooting after 7-10 days have passed [5].The plants were extracted from the pots and washed with water to get rid of the leftover nests sticking to their roots, after which the plants were immersed for 15 seconds with Beltanol (bacterial fungicide) at a concentration of 1 ml / L to prevent fungal infection.
The plants were planted in plastic pots with a diameter of 5 cm, filled with a medium consisting of peat moss and mixtures in a ratio of 1: 1 for10 replicates per treatment. The pots were covered with transparent plastic covers and incubated in the growth room under the same environmental conditions that the cultivated samples incubated. After two weeks of planting, the covers were gradually opened, taking into account watering with MS solution, a quarter of the salt strength, and the covers were lifted permanently after 4 weeks of planting and transferred to the greenhouse. The experiments were carried out using Complete Randomized Design and the results were analyzed using the SAS [6].

Results and Discussion
Establishment stage: There were significant differences in the percent of nodes for the red cultivar with different concentrations (Table1). The application of NAA at 0.2 mg/L gave the highest average response of (67.5%), which is significantly differed from the rest of treatments; and lowest response was  The application of BA at 1.5 mg/ L gave significantly high response (62.50%), which is differed significantly as compared with the treatments. The concentration of 1.5 mg / l BA + 0.2 mg / l NAA gave the highest percent (90%) compared to the rest of the treatments and may be due to the availability of the ideal ratio between auxin and cytokine to occur the response.   As for the effects of BA and IAA concentrations on the branches lengths of the white dianthus cultivar, the results of Table ( Table (  differences for the application of IBA in the number, length and percentage of rooting. The same table shows that the concentration of 1.0 mg / l IBA gave the highest percent of rooting and the highest root length of (80%) and (2.19 cm), respectively. Compared to the comparison treatment, while the treatment 1.5 mg / L IBA gave the highest number of roots (2.30). Experiment with Rooting EX Vitro: Results in Table ( Table ( [7]. Perhaps the reason of applying the IBA to the rooting medium is that the IBA is characterized by slow decomposition due to the effect of the Auxin-analyzing enzymes, which is a desirable feature in keeping the Auxin longer in the tissues. Therefore, IBA is the best in rooting branches, and these results were in agreement with [8] that confirmed that IBA is the best in rooting branches of Gardenia plants.