Bulgarian Chemical Communications, Volume 50, Issue 2, (pp. 315 –323) 2018

Effects of polyacrylate and on growth and physiological characteristics of different flue-cured tobaccos W.X. Huang*, Z.Z. Wei, G.Y. Niu, Y.J Zhang, H.F. Shao* College of Tobacco Science, Henan Agricultural University, Zhengzhou, Henan, 450002, China Received January 14, 2018; Accepted February 7, 2018 To investigate water retention effects and physiological regulation mechanism of water-retaining agents on the growth and development of different flue-cured tobacco varieties, a pot experiment was conducted using ‘Yuyan 6’ and ‘Yuyan 10’ to study the effects of sodium polyacrylate and potassium polymer on the agronomic characteristics, the root activity, the activity of antioxidant enzymes, the content of malondialdehyde (MDA) and proline in the leaves of flue-cured tobaccos. The results were as follows. (1) The application of water-retaining agents increased the plant height, the stem diameter, the number of effective leaves, the maximum leaf area and the root activity of flue-cured tobaccos and the effects were more significant for Yuyan 10 of relatively poor drought resistance. (2) The activity of SOD, POD and CAT of flue-cured tobaccos treated with water-retaining agents was reduced to different extents. (3) The application of water-retaining agents lowered the MDA content of flue-cured tobaccos but the effects were more significant for Yuyan 10 of relatively poor drought resistance. (4) The application of water-retaining agents decreased the proline content of flue-cured tobaccos under drought conditions, but the decrease of proline content in Yuyan 6 was larger than that in Yuyan 10. Yuyan 6 was highly drought-tolerant, so water-retaining agents could better promote the adaptability of Yuyan 10 to drought stress. Furthermore, water-retaining agent potassium polymer showed a stronger regulatory capability for the growth and physiological metabolism of flue-cured tobaccos than water-retaining agent sodium polyacrylate. Keywords: Water-retaining agents; Flue-cured tobaccos; Growth; Physiological characteristics INTRODUCTION surface runoff [7-9], thus playing a key role in the response to drought stress [10]. Y.H, Yang et al. Tobacco is one of the important economic crops found that the application of water-retaining agents in China [1]. Moisture is a major consistent of increased the soil moisture content in different tobacco plants, as well as an indispensable growth stages of winter wheat, as well as the environmental factor in the growth and metabolism accumulation of dry matter [11]. D.H. Liu et al. of tobacco [2]. At present, many soils of the world also proved that water-retaining agents significantly are rather short of water resources, especially in promoted the photosynthetic productivity and the agricultural production [3]. The shortage of water accumulation of biomass of potatoes [12]. Under resources in tobacco cultivation is intensified day drought conditions, the application of water- by day. Drought stress gives rise to serious retaining agents is of importance in the growth of abnormal physiological and biochemical changes of tobaccos [13-15]. In this paper, a pot experiment tobacco plants and further decreases the output and was conducted using ‘Yuyan 6’ of relatively good quality of tobacco leaves [4]. Therefore, it is of drought resistance and ‘Yuyan 10’ of relatively great significance to develop drought-resistant and poor drought resistance [16] to study the effects of water-saving tobacco cultivation and achieve sodium polyacrylate [(C3H3NaO2)n] and potassium superior quality and stable output of flue-cured polymer on the agronomic characteristics, the root tobaccos. activity, the activity of antioxidant enzymes, the In recent years, water-retaining agents, have contents of malondialdehyde (C3H4O2 ) (MDA) and been rapidly introduced in agricultural production proline (C5H9NO2) in tobacco leaves (see Fig. 1.), as anti-drought chemical agents which can soon aiming to figure out the physiological regulation absorb moisture hundreds of times as much as their mechanism of different water-retaining agents in mass [5]. The role of water retaining agents has the growth of flue-cured tobaccos and provide caught the attention of experts from the whole theoretical references for water-saving tobacco world [6]. Water-retaining agents can improve the cultivation. infiltration rate of soil moisture and reduce direct

* To whom all correspondence should be sent. © 2018 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria E-mail: : [email protected]; [email protected] 315 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological …

Fig. 1. a: Chemical structure of malondialdehyde; b: Chemical structure of proline.

Fig. 2. Chemical structure of the effective components in two water retaining agents. A: Changhao anti-drought water-retaining agent; B: Shenghua water-retaining agent. EXPERIMENTAL DETAILS Luoyang’s Luoning tobacco workstation and cultivated in plastic pots with a row spacing of 100 The pot experiment was conducted under a cm×50 cm. Each plastic pot had a height of 35 cm, rainproof shelter in the agricultural experimental an inner diameter of 40 cm and was filled with 20.0 zone of the new campus of Henan University of kg of cinnamon sandy soil which passed through a Science & Technology in Luoyang in 2015. Two 0.5 cm×1 cm mesh sieve and contained organic water-retaining agents were applied (Fig. 2.): A. matter 19.8 g/kg, available nitrogen 67.6 mg/kg, Changhao anti-drought water-retaining agent, rapidly available phosphorous 14.5 mg/kg and which was mainly composed of sodium rapidly available potassium 147.5 mg/kg, with a pH polyacrylate [(C H NaO ) ], white, granulated, 3 3 2 n value of 7.45. In all treatments, NPK fertilizer and crystalline, with a water absorption rate of 150 5 g of pure nitrogen were applied to each pot. times, purchased from Changhao Environmental N:P O :K O=1:1.5:3. Where necessary, Science & Technology Co, Ltd; B. Shenghua water- 2 5 2 phosphate and potassium sulfate were used to retaining agent, which was a kind of potassium supplement inadequate phosphorus and potassium. polymer absorbent material prepared with modified The flue-cured tobacco plants were transplanted [(C H O ) ], acrylonitrile (C H N) and 6 10 5 n 3 3 on May 21, 2015. A total of six treatments were acrylamide (C H NO), white powdered, with a 3 5 designed (Table 1) and 50 flue-cured tobacco plants water absorption rate of 200 times, provided by were cultivated in 50 pots separately in each Changsha Shenghua Science & Technology treatment, totaling 300 flue-cured tobacco plants. Development Co., Ltd. Before transplanting, water-retaining agents, NPK The flue-cured tobaccos for the experiment were ‘Yuyan 6’ and ‘Yuyan 10’ provided by Table 1. Experimental treatments Treatments Water Retaining Agents Yuyan 10 CK Without water retaining agents Yuyan 10 T1 With water retaining agent A (sodium polyacrylate) Yuyan 10 T2 With water retaining agent B (potassium polymer) Yuyan 6 CK Without water retaining agents Yuyan 6 T1 With water retaining agent A (sodium polyacrylate) Yuyan 6 T2 With water retaining agent B (potassium polymer) 316 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological … fertilizer and soil were homogeneously blended and significantly above that in CK treatment by 31.9%, put into pots. Then, the flue-cured tobacco plants 25.2% and 18.4%, respectively; on the 30th d, 45th d were watered with 2 L to resume growth and the and 60th d after transplanting, the maximum leaf watering volumes were equal in all treatments. area of Yuyan 10 in T2 treatment increased by Afterwards, the maximum field capacity was 27.5%, 42.9% and 20.8% respectively in measured using the cutting-ring method [17], and comparison with CK treatment; on the 60th d and TDR-100 soil moisture content analyzer 75th d after transplanting, the number of effective (SPECTRUM, USA) was used to determine the soil leaves of Yuyan 10 in T2 treatment was moisture content. The flue-cured tobacco plants significantly higher than that in CK treatment by were subject to moderate water stress 10 d before 10.0% and 13.5%, respectively. The plant height, sampling and measurement based on relative soil the number of effective leaves and the maximum moisture contents at 50%, 70% and 60% of the leaf area of Yuyan 6 were T2＞T1＞CK in different maximum field capacity in the root extending stage, growth stages, but the differences were the vigorous growth stage and the maturity stage, insignificant. Thus, it can be inferred that the respectively. application of water-retaining agents could promote The plant height and the maximum leaf area of the growth of flue-cured tobaccos but the flue-cured tobaccos were measured using a tape of promotional effects on Yuyan 10 of relatively poor millimeter graduation, the stem diameter was drought resistance were more significant. measured with a vernier caliper and the number of The root system is an important organ for effective leaves was recorded at the time [17], in of nutrients and moisture in soil and the which the maximum leaf area = the maximum leaf root activity directly affects the drought resistance length × the maximum leaf width × 0.6345 (the leaf of crops [20-22]. As can be seen from Table 3, from area index of flue-cured tobacco). the 30th d to the 75th d after transplanting, the root The sampling began 30 d after transplanting and activity of flue-cured tobaccos increased at first, later was conducted at 9:00 a.m. every 15 d. The reached a maximum on the 60th d after top-down fifth fully-expanded leaves of three flue- transplanting and decreased from then on in cured tobacco plants were collected in each different treatments. The root activity of Yuyan 6 treatment each time. The fresh samples were placed was higher than that of Yuyan 10 in CK treatment in an ice tray and brought back to laboratory soon. and the application of water- retaining agents The measurement of different indicators was improved the root activities of both Yuyan 10 and repeated three times. The root activity was Yuyan 6. On the 30th d after transplanting, the root measured using the TTC method [18]; superoxide activity of Yuan 10 in T1 and T2 treatments dismutase (SOD) activity was determined using the displayed significant differences from that in CK nitroblue tetrazolium reduction method [19]; treatment; 45 d, 60 d and 75 d after transplanting, peroxidase (POD) activity was measured with the the root activity of Yuan 10 in T2 treatment was guaiacol method [18]; catalase (CAT) activity was significantly different from those in T1 and CK determined using the absorption method treatments; what’s more, on the 60th d after [19]; malonaldehyde (MDA) content was measured transplanting, the root activity of Yuyan 10 in T2 by the thiobarbituric method [18]; proline treatment was higher than those in T1 and CK content was determined by the ninhydrin method. treatments by 29.4 RESULTS AND DISCUSSION % and 25.0%, respectively. From 30 d to 60 d after transplanting, the root activity of Yuyan 6 had no It can be seen from Table 2 that the plant height, significant differences; 75 d after transplanting, the the stem diameter, the number of effective leaves root activity of Yuyan 6 in T2 and T1 treatments and the maximum leaf area of Yuyan 6 were larger significantly differed from that in CK treatment and than those of Yuyan 10 in CK treatment and that the increased by 138.33 µg/(g·h) and 249.44 µg/(g·h), application of water- retaining agents increased the respectively. Therefore, it can be concluded that the plant height, the stem diameter, the number of application of water- retaining agents could effective leaves and the maximum leaf area of both enhance the root activity of flue-cured tobaccos and Yuyan 6 and Yuyan 10 under drought stress. On the was favorable to the growth of the root system 30th d, 45th d and 75th d after transplanting, the plant under drought conditions. height of Yuyan 10 in T2 treatment was

317 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological … Table 2. Comparison of agronomic characteristics of flue-cured tobacco plants in different treatments Flue-cured Days after transplanting (d) Indicators Treatments Tobaccos 30 45 60 75 CK 15.67±1.53 b 47.67±7.02 b 70.00±3.46 ab 100.50±0.71 b Yuyan 10 T1 17.33±1.53 ab 53.67±1.53 ab 72.00±10.15 a 109.00±1.41 ab Plant T2 20.67±2.08 a 59.67±4.04 a 78.67±6.66 a 119.00±9.90 a height/cm CK 20.33±2.31 a 55.33±1.53 a 76.00±5.57 a 117.50±10.61 a Yuyan 6 T1 22.33±1.53 a 54.33±6.03 a 79.67±11.93 a 120.00±19.80 a T2 24.33±2.31 a 58.67±0.58 a 87.67±14.64 a 127.50±3.54 a CK 3.80±0.17 a 7.13±0.61 a 7.50±0.87 a 7.25±0.35 a Yuyan 10 T1 3.83±0.29 a 7.33±0.29 a 7.60±0.36 a 7.50±0.71 a Stem T2 4.00±0.50 a 7.83±0.76 a 8.17±0.29 a 8.00±0.00 a diameter/cm CK 3.83±0.29 a 7.83±0.29 b 7.83±0.29 a 8.00±0.00 a Yuyan 6 T1 3.93±0.06 a 8.33±0.58 ab 8.00±0.00 a 8.25±1.06 a T2 4.00±0.00 a 9.00±0.50 a 8.17±0.76 a 8.25±0.35 a CK 9.33±1.15 a 13.00±0.00 a 16.67±0.58 b 18.50±0.71 b Yuyan 10 T1 9.67±0.58 a 13.33±0.58 a 18.00±0.00 a 20.50±0.71 a Number of T2 10.00±1.00 a 13.33±1.15 a 18.33±0.58 a 21.00±0.00 a effective CK 10.00±1.00 a 14.67±0.58 a 17.00±1.00 a 19.00±1.41 a leaves Yuyan 6 T1 11.00±1.73 a 15.00±1.00 a 17.33±1.53 a 20.00±1.41 a T2 10.67±0.58 a 15.33±0.58 a 19.00±1.00 a 21.50±0.71 a CK 386.83±28.18 b 692.66±58.28 b 928.92±26.23 b 1054.68±134.80 a Yuyan 10 T1 432.94±32.50 b 870. 27±51.76 ab 956.00±122.59 ab 1206.26±102.19 a Maximum T2 493.34±9.03 a 990.10±155.69 a 1122.43±101.14 a 1249.68±410.57 a leaf CK 447.96±71.40 a 755.00±86.26 a 938.64±112.61 a 1355.50±68.59 a area/cm2 Yuyan 6 T1 499.25±32.10 a 913.77±215.12 a 1144.50±180.36 a 1452.00±69.30 a T2 526.00±42.99 a 941.15±114.95 a 1147.86±107.37 a 1472.25±113.49 a Note: The data followed by different letters in each column are not significantly different at 0.05 level from each other according to Tukey Test. The same as below. Table 3. Comparison of root activities of flue-cured tobaccos in different treatments, unit: µg/(g·h) Flue-cured Days after transplanting (d) Treatments Tobaccos 30 45 60 75 CK 218.89±21.21b 458.89±19.64b 585.00±28.28b 130.00±30.64b Yuyan 10 T1 338.89±46.35a 514.72±57.75b 605.56±25.93b 239.44±25.14b T2 445.56±35.36a 650.00±25.93a 757.22±40.86a 387.22±45.57a CK 290.56±7.86a 538.33±153.99a 646.11±50.28a 235.00±42.43b Yuyan 6 T1 377.22±66.00a 637.78±71.50a 701.11±62.07a 373.33±7.07a T2 375.56±76.21a 707.78±54.21a 704.44±40.07a 484.44±43.21a

Fig. 3 shows that the SOD activity declined in treatments. The increase in the POD activity in the the whole growth stage in the different treatments. late growth stage was probably the result of From 30 d to 75 d after transplanting, the SOD physiological and biochemical reactions of flue- activities of Yuyan 10 in different treatments were cured tobacco plants in the maturity and senescence T2

318 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological … 400 a ） a 350 b U/g.FW a Yuyan 10 in CK treatment （ 300 a a a a a Yuyan 10 in T1 treatment 250 a ab a a c b a Yuyan 10 in T2 treatment

cured cured tobacco 200 - b Yuyan 6 in CK treatment 150 c Yuyan 6 in T1 treatment 100 a a b c b b Yuyan 6 in T2 treatment 50

The content of SOD in flue in of SOD The content 0 30 45 60 75 Days after transplanting (d) Fig. 3. Comparison of SOD activities of flue-cured tobacco leaves in different treatments

Fig. 4. Comparison of POD activities of flue-cured tobacco leaves in different treatments

Fig. 5. Comparison of CAT activities of flue-cured tobacco leaves in different treatments It can be seen from Fig. 5 that the CAT activity transplanting, the CAT activities of Yuyan 10 in T1 gradually decreased in the whole growth stage in and T2 treatments dropped by 44.3% and 46.8 % in the different treatments. 60 d and 75 d after comparison with CK treatment; on the 75th d after transplanting, the CAT activities of Yuyan 10 transplanting, the CAT activities of Yuyan 10 in T1, treated with water retaining agents had significant T2 and CK treatments showed significant differences from those in CK treatment; 60 d after differences. The CAT activities of Yuyan 6 were 319 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological … T2

1000

a

）

g/g

µ （ 800 a

a Yuyan 10 in CK treatment a ab Yuyan 10 in T1 treatment

cured tobacco cured 600 - ab b Yuyan 10 in T2 treatment b aa a Yuyan 6 in CK treatment 400 a b b b ab Yuyan 6 in T1 treatment b bb b Yuyan 6 in T2 treatment 200 b

b Thecontent ofinprolineflue 0 30 45 60 75 Days after transplanting (d) Fig. 6. Proline contents of flue-cured tobacco leaves in different treatments

320 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological … Thus, it can be inferred that the application of The dynamic balance between production and water-retaining agents reduced the proline contents scavenging of active oxygen in plants is broken of both Yuyan 6 and Yuyan 10 under drought stress under drought conditions so that a great deal of but the reduction effects on the former were larger active oxygen is accumulated in plants, which leads than those on the latter. to cellular membrane lipid peroxidation. MDA is the final product of the cellular membrane lipid CONCLUSIONS peroxidation and the higher the MDA content, the The root system is the main organ for absorption greater damages plants suffer from [28]. Our of water and nutrients for tobacco plants and experimental results showed that the application of directly affects the growth of flue-cured tobaccos water retaining agents reduced the MDA contents [24]. Apart from the genetic factors, the growth of of flue-cured tobaccos and the reduction effects on the root system is mainly affected by the Yuyan 10 of relatively poor drought resistance were environmental factors like moisture content, more significant. nutrients in soil, etc. Therefore, the root activity is The MDA content in leaves of Yuyan 6 was closely related to the soil moisture content. J. Zhang significantly lower than that of Yuyan 10, which et al. [25] proved that the root activity of flue-cured indicated that Yuyan 6 was able to reduce the tobaccos declined under drought stress. Our cellular membrane lipid peroxidation under drought experimental results showed that the root activity of stress and the tissue membrane system of Yuyan 6 Yuyan 6 was higher than that of Yuyan 10 under had a stronger drought-resistant ability. In drought conditions without applying water- comparison with Yuyan 10, Yuyan 6 could better retaining agents, so it can be inferred that the adapt to the drought stress. When plants suffer from physiological metabolism of the root system of a drought, a great deal of osmotic regulation Yuyan 6 was more active. The application of water- substances is accumulated within plants and the retaining agent B (potassium polymer) enhanced osmotic potential is reduced so as to adjust the cell the root activity of flue-cured tobaccos in the turgor and maintain normal life activities [29]. In different growth stages. This is probably due to the general, proline exists in plants in the free state and application of a water-retaining agent which is an important osmotic regulation substance within improves the soil aeration or a soil moisture sub- plants. The proline content can reflect the stress environment is formed around the root system and degree for plants to some extent [30]. The proline both water and nutrients are effectively conserved. content in plants is rather small (0.20~0.69 mg/g) The production and scavenging of active oxygen under normal conditions but a great deal of proline in plants are in dynamic balance under normal is accumulated under drought conditions [31]. H.Y. conditions but a great deal of active oxygen will be Lu et al. [31] came to the conclusion that the accumulated under adverse stress, so the anti- application of water-retaining agents could decrease oxidant enzymes like SOD, POD and CAT are of the contents of MDA and proline in leaves. Our great importance to maintain the physiological experiment showed that the application of water- functions of cells. According to relevant studies, the retaining agents reduced the proline content of activity of anti-oxidant enzymes in plants generally tobacco leaves but water- retaining agent B shows an increasing tendency under drought (potassium polymer) had more significant reduction conditions [26]. B.L. Xiao et al. [27] found that effects. Under drought conditions, the proline drought increased the SOD activity of flue-cured content of Yuyan 6 was largely increased, which tobacco. In our experiment, it was found that the was favorable to osmotic regulation, reduction of SOD and CAT activities of Yuyan 6 were higher osmotic potential and improvement of drought- than those of Yuyan 10 but the POD activity of resistant ability, while the proline content of Yuyan Yuyan 10 was higher than that of Yuyan 6 under 10 was slightly increased and the drought resistance drought stress without applying water retaining of Yuyan 10 was poor. agents. This was probably because the POD activity It is reported that the constituents of water- reflected the extent of stress damages and the retaining agents, the soil conditions of experimental higher the POD activity, the weaker was the fields, the crop species for experiment, as well as drought resistance of flue-cured tobaccos. The the experimental conditions like local climate may application of water-retaining agents reduced the lead to differences in experimental results [32]. X.J. SOD, POD and CAT activities of flue-cured Guan et al. [33] showed that more than 90% of tobaccos but the reduction effects were diversified. water conserved by high-quality water-retaining It can be inferred that flue-cured tobaccos differed agents of good performance could be taken in by in their responses of anti-oxidant enzymes to plants but about 1/3 of water conserved by water- drought. retaining agents of poor performance could not be

321 W.X. Huang et al.: Effects of sodium polyacrylate and potassium polymer on growth and physiological … absorbed by plants. Some relevant studies suggest Hemantarajan, editor), Springer Netherlands.Vol. 15, , that an overdose of sodium which 274, p. 251 (2005) participates in cross-linking may 11. Y.H, Yang, P.T. Wu, J.C. Wu, S.W. Zhao, X.N. Zhao, result in an impairment of plants and soil structure Z.B. Huang, Trans. CSAE , 26, 19 (2010) but the water retention performance and stability 12. D.H. Liu, Z.B. Huang, L.J. Cai, Z.X. Wei, Acta Agriculturae Boreali-occidentalis Sinica. 17, 266 will be improved and water retaining agents will be (2008) conducive to the growth of plants and soil 13. Q.D. Han, Y. Liu, Y.T. Han, L.X. Liu, M.J. Yang, B.D. amelioration after degradation if potassium acrylate Xie, Chinese Tobacco Sci., 36, 68 (2015) is put into use [34]. In our experiment, water 14. Y. Li, H. Shen, Z.H. Jia, W.X. Pu, Z.J. Sun, Y.F. retaining agent B (potassium polymer) is mainly Wang, Chinese Tobacco Sc., 3, 10 (2013) composed of potassium acrylate and has a moderate 15. Z. Chen, J.Y. Xu, Y.K. Fan, W.X. Huang, P.W. Wang, water absorption rate, so its water retention ability X.Y. Wen, Chinese J. Eco-Agric., 24, 1508 (2016) and stability are better and promotional effects for 16. L. Wang, J.C. Zhang, X.Q. Zhang, L. Meng, L. Zhai, the growth and physiological regulation capability J. Southwest Forestry Univ., 30,6 (2010) of flue-cured tobaccos are more significant than 17. X.H. Chen, S. Guo, G.S. Liu, L.Y. Qiu, M.D. Wang, J. Xinyang Normal Univ.y, 1, 47 (2014) those of water- retaining agent A (sodium 18. L.M. Lu, Beijing Sci., 1, 197 (2013) polyacrylate). Instead, water-retaining agent A 19. Q. Sun, J.J. Hu. Northwest Agric. Fores. Univ. Sci. (sodium polyacrylate) is mainly composed of Technol., 66, 165 (2006) sodium acrylate and its effects on the growth of 20. S. Asseng, J.T. Ritchie, A.J.M. Smucker, Plant and flue-cured tobaccos in different growth stages are Soil, 201, 265 (1998) weaker. Above all, the growth and physiological 21. R. Motzo, G. Attene, M. Deidda, Euphytica, 66,197 metabolism of flue-cured tobaccos can be improved (1992) as long as proper water-retaining agents are applied. 22. Y.X. Xu, L.X. Bei, H. Zhang, G.B. Yu, K.J. Yang, C.J. Zhao, Plant Physiol. J., 52, 101 (2016) Acknowledgements: This work was supported 23. L.B. Yang, H.F. Shao, X.J. Zhang, J.J. Yu, X.M. Ma, by the program of the Education Department of Tobacco Science &Technology, 10, 45 (2002) Henan Province (17A210020). 24. X.Y. Shang, H.B. Liu, X.Q. Zhang, J. Lin, W.J. Duan, Acta Botanica Boreali-Occidentalia Sinica, 30, REFERENCES 357 .(2010) 1. H.W. Niu, Z.C. Xu, H.F. Shao, L. Luo, R.R. Zhao, Y.X. 25. J. Zhang, H. Liu, X.P. Li, M. Lu, S.G. Sun, J.N. Su, Xiao, W.L. Yang, K.G. Wang, Acta Tabacaria Sinica, Agric. Res. Arid Areas, 3, 1 (2014) 5, 39 (2012). 26. Y.B. Yun, J.X. Li, F.Z. Ding, X.K. Su. Chinese 2. G.S. Liu, J.H. Chen, Beijing, Science, 3, 1, 2012. Tobacco Sci., 30, 10 (2009) 3. M.R. Islam, A.E. Eneji, C.Z. Ren, Y.G. Hu, G. Chen, 27. B.L. Xiao, D.M. ,Li, L.X. Liu. J..Henan Agric. Sci., X. Z. Xue, J. Agric. Biotechnol.Ecol., 3, 1 (2010). 11, 36 (2010) 4. B.W, Cui, Y.G, Lu, Z.Z. Zhang, K. Ren, Chinese 28. H.L. Hu, J. Zhang, T.X. Hu, L.H. Tu, Y.X. Pan, F.M. Tobacco Sci., 30, 19 (2009) Zeng, Acta Botanica Boreali-Occidentalia Sinica, 34, 5. Y. Shi, J. Li, J. Shao, S. Deng, R. Wang, N. Li, Scientia 118 (2014) Horticulturae, 124, 268 (2010) 29. J.Y. He, Y.F. Ren, Y.Y. Wang, Z.J. Li, Acta Ecologica 6. M. Sadeghi, H. Hosseinzadeh, Asian J. Chem., 22, Sinica, 31, 522 (2011) 6743 (2010) 30. P. Qin, Y.J. Liu, F.H. Liu, Chinese Tobacco Sci., 26, 7. A.R. Sepaskhah, A.R. Bazrafshan-Jahromi, Biosys. 28 (2005) Eng., 93, 469 (2006) 31. H.Y. Lu, Y.Y. Liu, F.W. Gao, S.G. Luo, J. Northeast 8. W.J. Busscher, D.L. Bjorneberg, R.E. Sojka, Soil Agric. Univ., 37, 299 (2006) Tillage Res., 104, 215 (2009) 32. Z.B. Huang, G.Z. Zhang, Y.Y. Li, M.D. Hao ,Meni 9. J. Akhter,K. .Mahmood,.K.A. Malik, A. Mardan, M. Ben-Hur, Trans. CSAE, 18, 22 (2002) Ahmad, M.M. Iqbal, Plant Soil & Environ., 50, 463 33. X.J. Guan, J.C. Wu, J. Henan Agri. Sci., 7, 13 (2007) (2004) 34. W. Huang. J.H. Zhang, L.F. Zhang, Y.H. Liu, Y.H. 10. I.C. Dodd, in: Advances in Plant Physiololgy (A. Wang, Chinese J. Ecol., 34, 1910 (2015)

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ВЛИЯНИЕ НА НАТРИЕВ ПОЛИАКРИЛАТ И КАЛИЕВ ПОЛИМЕР ВЪРХУ РАСТЕЖА И ФИЗИОЛОГИЧНИТЕ ПАРАМЕТРИ НА РАЗЛИЧНИ ОПУШЕНИ ТЮТЮНИ У.Кс. Хуан*, З.З. Уей, Г.И. Ниу, И.Дж. Джан, Х.Ф. Шао* Колеж по изучаване на тютюна, Хенански селскостопански университет, Женкжоу, Хенан, 450002, Китай Постъпила на 14 януари, 2018 г.; коригирана на 7 февруари, 2018 г. (Резюме) За изучаване на задържането на водата и механизма на физиологичното регулиране на водозадържащи агенти върху растежа и развитието на различни сортове опушени тютюни е проведен експеримент в саксии със сортовете ‘Yuyan 6’ и ‘Yuyan 10’. Изследвано е влиянието на натриев полиакрилат и калиев полимер върху агрономичните характеристики, кореновата активност, активността на антиоксидантните ензими, съдържанието на малонов дианхидрид (MDA) и пролин в листата на опушени тютюни. Установено е следното: (1) Използването на водозадържащи агенти води до повишаване на височината на растението, диаметъра на стъблото, броя на ефективните листа, максималната площ на листата и кореновата активност на опушените тютюни и влиянието е по-силно изразено при сорта Yuyan 10, характеризиращ се с по-малка издържливост на суша. (2) Активността на SOD, POD и CAT на опушените тютюни, третирани с водозадържащи агенти намалява в различна степен. (3) Прилагането на водозадържащи агенти понижава съдържанието на MDA, но ефектът е по-силно изразен при Yuyan 10. (4) Прилагането на водозадържащи агенти понижава съдържанието на пролин по-съществено при Yuyan 6, отколкото при Yuyan 10. Yuyan 6 е по-толерантен към суша, така че водозадържащите агенти стимулират по-добре адаптирането на Yuyan 10 към стрес от суша. Калиевият полимер демонстрира по-силен регулаторен капацитет върху растежа и физиологичния метаболизъм на опушени тютюни от натриевия полиакрилат.

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