INFLUENCE OF TRIACONTANOL ON MORPHOMETRIC PARAMETERS AND NITRATE CONTENT IN HELIANTHUS ANNUS L. ..

© 2018 V. Baranov et al.; Published by the Ivan Franko National University of Lviv on behalf of Біологічні Cтудії / Studia Biologica. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://www.budapestopenaccessinitiative.org/ and Creative Commons Attribution 4.0 License), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. UDC 581.1 : 631.811 : 546.173

Studying of plant growth stimulants is an important task for scientists. Triacontanol Н 3 С(СН 2 ) 28 СН 2 ОН is a fatty alcohol, also known as melicylic alcohol or myricyl alcohol found in cuticular waxes of plants, and is a part of beeswax. Triacontanol was first dis covered as a component of alfalfa cuticular wax Medicago sativa L. Study of the bio logical activity of this alcohol began in the last century and continues in different coun tries. Industrial produced triacontinol sample obtained from the beeswax contains im purities of other fatty alcohols that can neutralize the effect of the triacontanol. Study of the industrial produced triacontanol sample from Huzhou Sifeng Biochem Co.Ltd, Chi na on growth and content of nitrates in sunflower and cucumber seedlings was con ducted. In the industrial produced triakontanol used in our experiments, the composi tion of alcohols was as follows: triacontanol 95.6%, dotirancontanol 1.9 %, octacosanol 1.3 %, nonaccosanol 0.38 %, and the rest (less than 0.5 %) belong to heptacosanol and hexacosanol. Our studies have shown that the preparation at a concentration of 1 mg/L increases morphometric indices of sunflower seedlings and cucumbers, while the con centration of 25 mg/L reduces them, and the concentration of 10 mg/L is almost unaf fected. With an increase of triacontanol concentration the content of nitrates decreased in both types of seedlings (however, within the statistical error), which may be explained by an increase in the intensity of the use of nitrates. Concomitant alcohols available in the industrial produced triacontanol sample, practically haven't any effect. In our opi nion, triacontanol can be applied in crop production to increase plant growth. Concentra tion of 1 mg/L is the most effective, and therefore, available for use in agriculture, as

INTRODUCTION
Triacontanol H 3 C(CH 2 ) 28 CH 2 OH is a fatty alcohol which contains 30 carbon atoms. Triacontanol was first discovered as a component of alfalfa cuticular wax Medicago sativa L. in 1983 [2], and nowadays is one of the methods of its extraction from bees wax [6]. Subsequently, it was found in other plants. In wheat, its contents is 3% of all free alcohols, among those found in leaf waxes [18]. It stimulates nitrogen fixation, en zyme activity, photosynthesis, absorption of mineral elements, the use of mineral ele ments, gene regulation, membrane stability and productivity of many crops [17,12,15]. There is evidence that exogenous triacontanol treatment increases the yield of such economically important plants as rice (Oryza sativa L.), wheat (Triticurn aesitivum L.), tomatoes (Lycopersicon esculentum Mill.), Common mushrooms [Vigna radiata (L.) Wil czek], corn (Zea mays L.) and hyacinth beans (Lablab purpureus L.) [8].
Also, triacontanol has a synergistic effect with the gibberellic acid shown to in crease in content of the essential oils, a mass of 1000 seeds, and the number of flowers in the coriander umbrella (Coriandrum sativum L.) and the number of umbrellas per plant [14]. The same effect of triacontanol was obtained in a study conducted in 2014 [13].
Information on the effect of the triacontanol on plant metabolism was actively inves tigated in the twentieth century. The effect of the triacontanol on dry weight of plants [10,3], the content of amino acids and proteins [9], CO 2 fixation activity [5] and an increase in the intensity of carbon dioxide fixation, reduction activity of photobreathing, increase of dry mass of plants. The influence on wheat, maize and rice was most actively inves tigated, but little is known about its impact on other important agricultural crops. Also, plant growth stimulators can improve stress resistance of plant [11]. Unfortunately, in Ukraine, and earlier in the former USSR, there aren't a lot of investigations related to the effects of the triacontanol on plants.
In addition, it is known that the concomitant alcohols can neutralize the action of the triacontanol [7]. In the industrial produced triacontanol sample used in our experiments, the composition of alcohol was as follows: triocontinol 95.6%, dotriancontanol 1.9 %, octacosanol 1.3 %, nonacosanol 0.38 %, and the rest belonged to heptacosanol and hexacosanol. Thus, the purpose of our work was to determine which changes occur after exogenous treating with this industrial produced triacontanol sample in the pre sence of the impurities of accompanying alcohols, in sunflower and cucumbers seed lings, and whether this industrial produced triacontanol sample will have a positive ef fect on growth and content of nitrates in seedlings.

MATERIALS AND METHODS
95% Triacontonol was provided by Huzhou Sifeng Biochem Co.Ltd, China to which we express our sincere gratitude. Since the triacontanol is insoluble in water, it was dissolved in a concentration of 25 mg/L with 0.5 ml of Tween20 in 100 ml of distilled water and heated to dissolve. After that, they were poured into a flask for 1 L and filled with a distillate. Other concentrations were prepared by dilution with water. To determine the effect of the triacontanol on the morphometric parameters of seedlings of plants, seeds were sprouted in Petri dishes on solutions of triacontanol in concentrations of 1, 10 and 25 mg/L for 7 days, in a dark thermostat with a temperature of 22 °C. 10 seeds were placed in each Petri dish, the experiment was carried out in triple repetition [4]. The determination of the content of nitrates was carried out in plants grown in pots on the garden soil, and sprayed with the triacontanol solution. Control was sprayed by the distillate, the spraying was carried out from 7 days after the day landing the seeds in the soil and spraying was repeated every three days for 4 weeks. The content of nitrates was determined using a technique with the Griss reagent [16]. The results were calcu lated in "Statist" software.

RESULTS AND DISCUSSION
The first stage of the research was to determine the effect of triacontanol on mor phometric parameters of sunflower and cucumbers seedlings ( Fig.1-4). As shown in Fig. 1, triacontanol at a concentration of 1 mg/L increased the length of the shoots and sunflower roots, and the concentration of 25 mg/L reduced both parameters. At the same time, the concentration of 10 mg/L did not cause any changes.
The use of triacontanol at concentrations of 1 and 10 mg/L increased the weight of the root and shoot of sunflower, and the concentration of 25 mg/L reduced these parameters, similar to the effect of this concentration on the length of the roots and shoots.
In the seedlings of cucumber, the same trend as in the seedlings of sunflower -the concentration of 1 mg/L increased the length of the shoots and slightly increased the length of the root, the concentration of 10 mg/L almost did not affect these indicators, and the concentration of 25 mg/L reduced them.
The triacontanol had a similar effect on the mass of roots and shoots of cucumber as on the length of shoots and roots. A use of triacontanol at the concentration of 1 mg/L  It is known that in early stages of development, when young plants are poor in carbohydrates, it is better to absorb the nitrates, because for the assimilation of ammonia it is needed organic acids, which are formed from carbohydrates which are needed to normal growth of seedling. So, the next stage of our study was to evaluate in the content of nitrates.
Spraying with a solution of triacontanol at first glance reduced the content of nitrates in all variants and in all plants, although the statistical error overrides this decrease, possibly due to a small number of repetitions that will be retested in field conditions.

CONCLUSIONS
Low concentrations of triacontanol in seedlings treatment of sunflower and cucum ber stimulated the utilization of nitrates, and high concentrations inhibited that process which will be retested in field conditions. The effect of optimal concentrations of tria contanol which stimulate growth of sunflower seedlings and cucumbers were accom panied by changes in the content of nitrates. Consequently, it can be assumed that treating with triacontanol can enhance growth by accelerating the utilization of nitrates and possibly by increasing a productivity of plants, as shown in iterature [1]. Since most effective dose of the triacontanol for sunflowers and cucumbers is 1 mg/L, its use will not be vere expensive, that will stimulate its use. Concomitant alcohols available in the industrial produced triacontanol, practically have no effect on studied parameters.