Document Type : Research Paper


1 Assistant Professor, Seed and Plant Improvement Institute. Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran.

2 Assistant Professor, Department of Genetics and Plant Breeding, Faculty of Agriculture and Natural Resources, Imam Khomeini International University, Qazvin, Iran.


In dry regions, root systems play a major role in controlling plant growth and yield, thanks to their importance in water absorption. In order to investigate the effect of irrigation regimes on root and shoot traits of sesame (Sesamum indicum L.) genotypes, a field experiment has been conducted in Karaj, at Seed and Plant Improvement Institute, during 2017 and 2018. A factorial experiment has been laid out in a completely-randomized design with four replications. This study deals with five genotypes of sesame in two irrigation regimes, including full and low (drought stress) irrigation treatments in terms of root and shoot-related traits. Results show that there have been significant differences between genotypes and irrigation regimes for root and shoot traits. In all genotypes, root length density is higher in full irrigation treatment as well as the upper soil layer (0 to 30 cm deep), compared to stress treatment. In addition, under drought stress conditions root depth increases (by 30% in average) in all genotypes. In contrast, root dry weight has decreased in Dashtestan 2 (15 %), Darab 1 (16 %), and Naz (22 %), and increased in Oltan (1 %), USA-ns 96 (7 %), and Sodan 94 (10 ) genotypes. On the other hand, the highest amount of shoot dry weight belongs to the USA-ns 96 genotype (39 g), and the lowest to Naz cultivar (22 g). Finally, results show that USA-ns 96 genotype, being superior in terms of root characteristics such as root depth and root length density compared to other genotypes, in addition to having more shoot dry weight, show the least dry weight loss under stress conditions.


Berntson, G.M. (1994). Modelling root architecture: are there tradeoffs between efficiency and potential of resource acquisition? New Phytologist, 127, 483-493.
Bengough, A.G., McKenzie, B.M., Hallett, P.D., & Valentine, T.A. (2011). Root elongation, water stress, and mechanical impedance: A review of limiting stresses and beneficial root tip traits.  Journal of Experimental Botany, 62, 59-68.
Brück, H., Sattelmacher, B., & Payne, W.A. (2003). Varietal differences in shoot and rooting parameters of pearl millet on sandy soils in Niger. Plant and Soil, 251, 175-185.
Costa, C., Dwyer, L.M., Zhou, X., Dutilleul, P., Hamel, C., Reid, L.M., & Smith, D.L. (2002). Root morphology of contrasting maize genotypes. Agronomy Journal, 94, 96-101.
Ebrahimian, E., Seyyedi, S.M., Bybordi, A., & Damalas, C. A. (2019). Seed yield and oil quality of sunflower, safflower, and sesame under different levels of irrigation water availability. Agricultural Water Management, 218, 149-157
Fageria, N. K. (2004). Influence of dry matter and length of roots on growth of five field crops at varying soil zinc and copper levels. Journal of Plant Nutrition, 27, 1517-1523.
Fang, Y., Du, Y., Wang, J., Wu, A., Qiao, S., Xu, B., Zhang, S., Siddique, K.H.M., & Chen, Y. (2017). Moderate drought stress affected root growth and grain yield in old, modern and newly released cultivars of Winter Wheat.  Frontiers in Plant Science, 8, 1-14.
Farre, L., & Faci, J. M. (2009). Deficit irrigation in maze for reducing agricultural water use in a mediterranean enviroment. Agricultural Water Management, 96, 383-394.
Figueroa-Bustos, V., Palta, J.A., Chen, Y., & Siddique, K.H.M. (2018). Characterization of Root and Shoot Traits in Wheat Cultivars with Putative Differences in Root System Size. Agronomy, 8, 109-123.
Fritschi, F.B., Roberts, B.A., Travis, R.L., Rains, D.W., & Hutmacher, R.B. (2003). Response of irrigated acala and pima cotton to nitrogen fertilizations: growth, dry matter partitioning, and yield. Agronomy Journal, 95, 133-146.
Ganapathy, S., Ganesh, S.K., Shanmugasundaram, P., & Chandra Babu, R. (2010). Studies on root traits for drought tolerance in rice (Oryza sativa L.) under controlled (PVC pipes) condition. Electronic Journal of Plant Breeding, 1(4), 1016-1020.
Gholamhoseini, M., Ghalavand, A., Khodaei-Joghan, A., Dolatabadian, A., Zakikhani, H., & Farmanbar, E. (2013). Zeolite-amended cattle manure effects on sunflower yield, seed quality, water use efficiency and nutrient leaching. Soil & Tillage Research, 126, 193-202.
Gregory, P.J. (2006). Plant Roots: Growth, activity and interaction with soils. Blackwell Publishing Ltd. UK.
Jongrungklang, N., Toomsan, B., Vorasoot, N., Jogloy, S., Boote, K.J., Hoogenboom, G., & Patanothai, A. (2012). Classification of root distribution patterns and their contributions to yield in peanut genotypes under midseason drought stress. Field Crops Research, 127, 181-190.
Jouyban, Z., & Moosavi, S.G.  (2012). Seed yield and some yield components of sesame as affected by irrigation interval and different levels of n fertilization and superabsorbent. African Journal of Biotechnical, 11(49), 10944-48.
Kenan, U., Kill, F., Gencoglan, C., & Merdan, H. (2007). Effect of irrigation frequency and amount on water use efficiency and yield of sesame under field condition. Field Crops Research, 101, 249-254.
Khan, M.A., Gemenet, D.C., & Villordon, A. (2016). Root system architecture and abiotic stress tolerance: Current knowledge in root and tuber crops. Frontiers in Plant Science, 7, 1-13.
Lafitte, H.R., Champoux, M.C., McLaren, G.. & O’Toole, J.C. (2001). Rice root morphological traits are related to isozyme group and adaptation. Field Crops Research, 71, 57-70.
Lynch, J.P., & Wojciechowski, T. (2015). Opportunities and challenges in the subsoil: pathways to deeper rooted crops. Journal of Experimental Botany, 66, 2199-2210.
Narayanan, S., Mohan, A., Gill, K.S., & Vara Prasad, P.V. (2014). Variability of root traits in spring wheat germplasm. PLOS ONE, 9(6), 1-15.
Palta, J.A., & Yang, J. (2014). Crop root system behaviour and yield. Field Crops Research, 165, 1-4.
Palta, J.A., Chen, X., Milroy, S.P., Rebetzke, G.J., Dreccer, M.F., & Watt, M. (2011). Large root systems: Are they useful in adapting wheat to dry environments? Functional Plant Biology, 38, 347-354.
Pardo, A., Amato, M., & Chiaranda, F.Q. (2000). Relationships between soil structure, root distribution and water uptake of chickpea (Cicer arietinum L.). Plant growth and water distribution. European Journal of Agronomy, 13, 39-45.
Purushothaman, R., Krishnamurthy, L., Upadhyaya, H.D., Vadez, V., & Varshney, R.K. (2017). Root traits confer grain yield advantages under terminal drought in chickpea (Cicer arietinum L.). Field Crops Research, 201, 146-161.
Sponchiado, B.N., White, J.W., Castillo, J.A., & Jones, P.G. (1989). Root growth of four common bean cultivars in relation to drought tolerance in environments with contrasting soil types. Experimental Agriculture, 25, 249-257.
Strock, C.F., Burridge, J., Massas, A.S.F., Beaver, J., Beebe, S., Camilo, S.A., Fourie, D., Jochua, C., Miguel, M., Miklas P.N., Mndolwa E., Nchimbi-Msolla, S., Polania, J., Porch, T.G., Rosas, J.C., Trapp, J.J., & Lynch J.P. (2019).  Seedling root  architecture  and  its  relationship  with  seed  yield  across  diverse environments  in  Phaseolus  vulgaris.  Field  Crops  Research,  237, 53-64.
Uga, Y., Sugimoto, K., Ogawa, S., Rane, J., Ishitani, M., Hara, N., Kitomi, Y., Inukai, Y., Ono, K., Kanno, N., Inoue, H., Takehisa, H., Motoyama, R., Nagamura, Y., Wu, J., Matsumoto, T., Takai, T., Okuno, K., & Yano, M. (2013). Control of root system architecture by DEEPER ROOTING 1 increases rice yield under drought conditions. Nature Genetics, 45, 1097-1102
Vadez, V. (2014). Root hydraulic: The forgotten side of roots in drought adaptation. Field Crops Research, 165, 15-24.
Waines, J.G., & Ehdaie, B. (2005). Optimizing root characters and grain yield in wheat. Czech Journal of Genetics and Plant Breeding, 41, 1-5.
Wasaya, A., Zhang, X., Fang, Q., & Yan, Z. (2018). Root Phenotyping for Drought Tolerance: A Review. Agronomy, 8(11), 241-261.
Zhang, X., Chen, S., Sun, H., Wang, Y., & Shao, L. (2009). Root size, distribution and soil water depletion as affected by cultivars and environmental factors. Field Crops Research, 114, 75-83.