Document Type : Original Article

Authors

Department of Agronomy, Ramhormoz Branch, Islamic Azad University, Ramhhormoz, Iran

Abstract

Introduction
Rice (Oryza sativa.L) is one of the most important grains in the world, which as one of the major food sources, provides food to more than three billion people in the world. In the near future, there are several challenges to achieve higher yields in rice plants, and one of the most basic of these challenges is increasing the average temperature of the earth's surface. Increasing the temperature indirectly reduces production by increasing water demand in areas with limited water and reducing the area under cultivation. Therefore, plant physiologists' understanding of plant physiological responses to high temperatures, as well as the selection of adaptation strategies, is an effective and very important role in rice research. In line with international research, research on introducing a diverse range of heat-tolerant rice cultivars on the one hand and finding effective physiological traits and mechanisms in tolerance or resistance of common rice cultivars in the province to this stress can play a valuable role in inactivation, modulation of negative effects or greater efficiency of the heat and light stress situation arising in the coming years. In other words, making management decisions regarding the production and use of improved cultivars, introducing native tolerant or heat-resistant cultivars and possible required changes in the temporal and spatial patterns of cultivation of cultivars, can be a significant help in combating heat stress. Therefore, this experiment was conducted to evaluate heat stress on grain yield and to study stress tolerance indices in studied cultivars in the Khuzestan region.
Materials and methods
In order to evaluate the stress tolerance and susceptibility indices of rice plant (Oryza sativa L.) in response to heat stress, an experiment with two factors of planting date and cultivar on the basis of split plots in a randomized complete blocks design with three replications in two years 2017 and 2018 were carried out in the south of Khuzestan province. In order to apply high temperature stress (heat stress) in field conditions, three planting dates of May 15, June 5 and June 25 were selected as the main plots. At each planting date, seven rice cultivars including Anbouri, Champa, Daniel, Pollen, Hamr, and Hoveyzeh (native cultivars) and N22 (International cultivar) were cultivated as sub-plots. Stress tolerance indices included GWHSI SSI, STI, TOL.
 Results and discussion
The results showed that at the level of planting date, the highest grain yield was on 5 June with a yield of 5737 kg.ha-1, which was 41.7 more than the first planting date. The highest grain yield was obtained among the cultivars related to Hoveyzeh with an average of 5606 kg.ha-1, which was 34.3% and 29.6% higher than Champa and Anbori, respectively. In evaluating stress tolerance indices, N22 and Hoveyzeh cultivars had the highest SSI and STI, Hammer and Hoveyzeh cultivars showed the highest STI and N22 and Hammer cultivars showed the lowest TOL. The lowest (SSI) was obtained in Hoveyzeh cultivar and then in Hamr and N22 cultivars. The lowest heat stress tolerance was also observed in Champa cultivar. Also, the highest STI index and the lowest TOL index were obtained in Hamr, N22 and Hoveyzeh cultivars. The lowest GDD in all three planting dates was in Hoveyzeh cultivar and the highest one was in sensitive cultivars to heat stress (Anburi and Champa).
Conclusions
In general, heat-tolerant cultivar N22, Daniel and local cultivars Hoveyzeh and Hamr were heat-tolerant cultivar and Geredeh Ramhormoz cultivar and Anbouri and Champa (native cultivars) were identified as heat-sensitive.
 

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Main Subjects

Agricultural Statistic of Jihad. 2020. Agricultural Organization of the Iran. www.maj.ir/ Dorsapax/userfiles/Sub65/Amarnamehj1-97-98-site.pdf.
Amiri, A., Bahrani, A., Khorsand, A., Hagh Joo M., 2016. Evaluating AquaCrop model performance to predict grain yield and wheat biomass, under water stress. Water and Soil Science. 25, 217-229. [In Persian with English Summary].
Bahrani, A., Haghjo M., 2016. Effect of planting date on grain yield and yield components of three winter oilseed rape (Brassica napus L.) cultivars in Fars province. Journal of Plant Ecophysiology. 8, 182-192. [In Persian with English Summary].
Blum, A., 1988. Plant Breeding for stress Environments. CRC Press Inc., Boca Raton, Florida, P. 223.
Bose, A., Ghosh, B., 1995. Effect of heat stress on ribulose 1,5-biphosphate carboxylase in rice. Phytochemistry. 38, 1115–1118.
Cheng, F., Zhong, L., Zhao, N., Liu, Y., Zhang, G., 2005. Temperature induced changes in the starch components and biosynthetic enzymes of two rice varieties. Plant Growth Regulation. 46, 87–95.
Cerioli, T.,  Gentimis, T.,  Linscombe, S.D., Famoso A.N., 2017. Effect of rice planting date and optimal planting window for Southwest Louisiana. Agronomy Journal. 113, 1248-1257.
Fernandez, G.C.J., 1992. Effective selection criteria for assessing plant stress tolerance. In: C.G., Kuo (Ed.), Adaptation of vegetables and other food crops in temperature and water stress. AVRDC Staff Publication, Shanhua. pp: 257-270.
Fischer, R.A., Maurer, R., 1978. Drought resistance in spring wheat cultivars. I. Grain yield responses. Australian Journal of Agricultural Research. 29, 897-912.
Gesch, R.W., Kang, I.H., Gallo-Meagher, M., Vu, J.C.V., Boote, K.J., Allen, L.H.J., Bowes, G., 2003. Rubisco expression in rice leaves is related to genotypic variation of photosynthesis under elevated growth CO2 and temperature. Plant Cell Environment. 26, 1941–1950.
Ghosh, B., Chakma, N., 2015. Impacts of rice intensification system on two C.D. blocks of Barddhaman district. West Bengal. Current Science. 109, 342-346.
Gilani, A.A., Siadat, S.A., Alemi Saeed, KH., Bakhshandeh, A.M., Moradi, F., Seyednejad, M., 2008. Determining the mechanisms of tolerance and physiological effects of heat stress in Khuzestan rice cultivars. PhD thesis in agriculture. Ahvaz Ramin University of Agriculture and Natural Resources. 185 pages. [In Persian].
Gilani, A.A., Siadat, S.A., Alami-Saeed, KH., Bakhshandeh, A.M., Moradi, F., Seidnejad M., 2009. Effect of heat stress on grain yield stability, chlorophyll content and cell membrane stability of flag leaf in commercial rice cultivars in Khuzestan. Iranian Journal of Crop Science. 11, 82-100. [In Persian with English Summary].
Hagh Joo, M, Bahrani A. 2014. Effect of irrigation and nitrogen fertilizer on grain yield, yield components and dry matter remobilization of maize cv. SC260. Iranian Journal  Crop Science. 16, 278-292. [In Persian with English Summary].
Jagadish, S.V.K., Craufurd, P.Q., Wheeler, T.R., 2008. Phenotyping parents of mapping populations of rice for heat tolerance during anthesis. Crop Science. 48, 1140–1146.
Lafitte, H.R., Yongsheng, G., Yan, S., Li, Z.K., 2007. Whole plant responses, key processes, and adaptation to drought stress: the case of rice. Journal of Experimental Botany. 58, 169-175.
Mackill, D.J., Coffman, W.R., Rutger, N.J., 1982. Pollen shedding and combining ability for high temperature tolerance in rice. Crop Science. 22, 730–733.
Moradi, F., 1996. Investigation of physiological effect of heat stress on 6 rice cultivars in Khuzestan. Master Thesis, Ramin Agricultural Higher Education and Research Complex, Shahid Chamran University of Ahvaz. [In Persian].
Prasad P.V.V., Bootem K.J., Allen, L.H., Sheehy, J.E., Thomas J.M.G., 2006. Species, ecotype and cultivar differences in spikelet fertility and harvest index of rice in response to high temperature stress. Field Crops Research. 95, 398–411.
Roy, M., and Ghosh, B., 1996. Polyamines, both common and uncommon, under heat stress in rice (Oryza sativa) callus. Plant Physiology. 98, 196–200.
Sedaghat, N., Pirdashti, H., Rahemi Karizaki, A., Safikhani S., 2017. Evaluation growth indices of two native and improved rice (Oryza sativa L.) cultivars in different irrigation managements. Journal of Plant Ecophysiology. 9, 40-52. [In Persian with English Summary].
Wassmann, R., Jagadish, S.V.K., Heuer, S., Ismail, A., Redona, E., Serraj, R., Singh, R.K., Howell, G., Pathak, H., Sumfleth, K., 2009. Climate change affecting rice production: The physiological and agronomic basis for possible adaptation strategies. Advances in Agronomy. 101, 59–122.
Welch, J.R., Vincent, J.R., Auffthammer, M., Moya, P.F., Dobermann, A., 2010. Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures. Proceedings of the National Academy of Sciences (PNAS). 107(33):14562-7. https://doi.org/10.1073/pnas.1001222107
Yoshida, S., Satake, T., Mackill, D.J., 1981. High-temperature stress in rice (Review). IRRI Resarch Paper Series 67, 5pp