نقش ساختار ریشه و صفات فیزیولوژیک جو در پاسخ به تنش خشکی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری مهندسی ژنتیک، دانشگاه تهران

2 استادیار، مؤسسۀ بیوتکنولوژی کشاورزی سازمان آموزش، تحقیقات و ترویج کشاورزی

3 دانشیار، پردیس کشاورزی و منابع طبیعی دانشگاه تهران

4 دانشیار، مؤسسۀ بیوتکنولوژی کشاورزی سازمان آموزش، تحقیقات و ترویج کشاورزی

5 استاد، پردیس کشاورزی و منابع طبیعی دانشگاه تهران

6 دانشجوی دکتری، دانشکدۀ کشاورزی، دانشگاه فردوسی مشهد

چکیده

تنش خشکی در اکثر مناطق جهان مهم‌ترین عامل کاهش عملکرد گیاهان زراعی محسوب می­شود. تنظیم اسمزی و داشتن سیستم ریشه­ای قوی و عمیق از طریق افزایش جذب و بازده مصرف آب، سبب افزایش تحمل به خشکی در غلات می­شود. در این تحقیق، تأثیر ساختار ریشه و صفات فیزیولوژیک در پاسخ به تنش خشکی در سه رقم جو زراعی یوسف (متحمل)، موروکو (حساس) و فجر30 (نیمه‌متحمل) و یک اکوتیپ جو غیر‌زراعی اسپانتانئوم (متحمل) بررسی شد. بذور جو در لوله­های پی‌وی‌سی 1 متری با قطر 10 سانتی‌متر کشت شدند و تنش خشکی به میزان 20 درصد مقدار آب در دسترس اعمال شد و آبیاری در حد ظرفیت زراعی به‌عنوان شاهد در نظر گرفته شد. خصوصیات ریشه و صفات فیزیولوژیک در ابتدای مرحلة گلدهی اندازه‌گیری شد. نتایج حاکی از این بود که در اثر خشکی، میزان هدایت روزنه­ای، محتوای نسبی آب برگ، پتانسیل آب برگ و پتانسیل اسمزی در همة ارقام کاهش و دمای برگ افزایش یافت. ارقام متحمل دارای کمترین افت پتانسیل آب، پتانسیل اسمزی و محتوای نسبی آب برگ بودند. رقم حساس دارای کمترین و ارقام متحمل دارای بیشترین میزان تنظیم اسمزی بودند. تنش خشکی موجب کاهش وزن خشک و حجم ریشه نسبت به شرایط کنترل شد. عمق ریشه در تمام ارقام متحمل و نیمه‌متحمل در اثر تنش افزایش یافت، درحالی که در رقم حساس کاهش نشان داد. نتایج نشان داد ارقام مقاوم ارقامی‌اند که در شرایط تنش می­توانند با افزایش عمق ریشه، آب بیشتری جذب کنند و در نتیجه دارای تنظیم اسمزی و محتوای نسبی آب بیشتری باشند. این ارقام در شرایط تنش به‌دلیل محتوای نسبی آب بیشتر، هدایت روزنه­ای بیشتری دارند و ازاین‌رو دمای برگ را در سطح پایین­تری نگه می‌­دارند.

کلیدواژه‌ها


عنوان مقاله [English]

The impact of barley root structure and physiological traits on drought response

نویسندگان [English]

  • Reza Kesahvarznia 1
  • Maryam Shahbazi 2
  • Valiolah Mohammadi 3
  • Ghasem Hosseini Salekdeh 4
  • Ali Ahmadi 5
  • Ehsan Mohseni-Fard 6
1 Ph. D. Student, Genetics Engineering, University of Tehran
2 Assistant Professor, Biotechnology Institute of Agricultural Educate
3 Associate Professor , University College of Agriculture & Natural Resources, University of Tehran, Karaj
4 Associate Professor, Biotechnology Institute of Agricultural Educate,
5 Assistant Professor, University College of Agriculture & Natural Resources, University of Tehran, Karaj
6 Ph. D. Student, Faculty of Agriculture, Ferdowsi University of Mashhad
چکیده [English]

abstract
Drought is the most important factor limiting crop yield word wide. Osmotic adjustment (OA) and strong and deep root system result in increased cereal drought tolerance through increasing water uptake and water use efficiency. The impact of root structure and physiological traits on drought stress response was studied in three barley cultivars including Yousof (drought tolerant), Morocco (susceptible), and Fajr30 (semi-tolerant) and an Iranian accession of wild species, Hordeom spontaneum (tolerant). Seeds were planted in PVC pipes 100 cm depth and 10 cm diameter. Two moisture regimes applied including a normal irrigation at field capacity (control), and drought stress at 20% available water. Root characteristics and physiological traits were measured ar flowering stage. Drought stress reduced stomatal conductivity, RWC, Leaf water potential, osmotic potential, OA and increased leaf temperature. Minimum decline in Leaf water potential, osmotic potential and RWC was observed in tolerant varieties (Yousof and H. spontaneum). The tolerant and susceptible varieties showed the highest and the lowest OA. Drought stress led to reduced root dry weight and volume in all varieties, susceptible variety showing the highest decline. Root depth increased under stress in all tolerant and semi-tolerant cultivars, while decreased in the susceptible one. The results showed that tolerant varieties are varieties which could uptake more water by increasing root depth leading to higher OA and higher RWC. Higher RWC results in more transpiration and lower leaf temperature under stress condition.

کلیدواژه‌ها [English]

  • Drought stress
  • relative water content
  • Osmotic adjustment
  • root volume
  • Root depth
Altinkut, A.K.K., Ipekci, Z. & Gozukirmizi, N. (2001). Tolerance to paraquat is correlated with the traits associated with water stress tolerance in segregating F2 populations of barley and wheat. Euphytica, 121, 81-86.
Asseng, A., Ritchia, J.T. & Smuchker, A.J.M. (1998). Root growth and water uptake during water deficit and recovering in wheat. Plant and Soil, 201, 265-273.
Atteya, A. (2003). Alteration of water relations and yield of corn genotypes in response to drought stress. Bulgarian Journal Plant physiology, 29, 63-76.
Blum, A. (1989). Osmotic Adjustment and Growth of Barley Genotypes under Drought Stress. Crop Science Journal, 29, 230-233.
Chaves, M.M., Junica, M. & Pereira, J.S. (2003). Understanding plant responses to drought-from genes to the whole plant. Functional Plant Biology, 30, 239-264.
Chimenti, C.A., Ppearson, J. & Hall, A.J. (2002). Osmotic adjustment and yield maintenance under drought in sunflower. Field Crop Research, 10, 235-246.
Demirevska, K., Samina, L., Vassileva, V., Vaseva, I., Grigorova, B. & Feller, U. (2008). Drought-induced leaf protein alterations in sensitive and tolerant wheat varieties. Gen App Plant Physiol, 34, 79-102.
Farooq, M., Wahid, A., Kobayashi, N., Fujita, D. & Basra, S.M. (2009). Plant drought stress: effects, mechanisms and management. Agronomy for Sustainable Development, 29, 185-212.
Garg, A.K., Owens, T.G., Ranwala, A.P., Choi, Y.D., Kochian, L.V. & Wue, R.J. (2002). Trehalose accumulation in rice plants confers high tolerance levels to different abiotic stresses. Proceedings of the National Academy of Sciences, 99, 15898-15907.
Ghamarnia. H., & Gorge, J. (2005). Effect of water stress on three wheat cultivars. Proceedings of the National Academy of Sciences, 99, 15-19.
Gonzalez, A., Morgan, I. & Ayerbe, L. (1999). Barley yield in water-stress conditions the influence of precocity, osmotic adjustment and stomatal conductance. Field crops research, 62, 23-34.
Gregory, P., Baum, A. & Yambao, J. (1991). The fate of carbon in pulse-labelled crops of barley and wheat. Plant& Soil Science, 136, 205-213.
Guo, P., Grando, S., Ceccarelli, S., Bai, G., Li, R., Von korff, M., Varshney, R.K., Graner, A. & Valkoun, J. (2009). Differentially expressed genes between drought-tolerant and drought-sensitive barley genotypes in response to drought stress during the reproductive stage. Journal of Experimental Botany, 60, 3531-3544.
Hosseini Salekdeh, G.R., John, R., Boyer, E. & John, M. (2009). Conceptual framework for drought phenotyping during molecular breeding. Trends in Plant Science, 14, 1360-1385.
Hsiao, T.C., Yambao, E.B. & Turner, N.C. (1984). Influence of osmotic adjustment on leaf rolling and tissue death in rice (Oryza sativa L.). Plant physiology Journal, 75, 338-341.
Khakwani, A.A., Dearin, M. & Munir, M. (2011). Drought tolerance screening of wheat varieties by inducing water stress conditions. Songklanakarin Journal of Science & Technology, 33, 135-142.
Khan, S. (2010). Resistance mechanisma in plants under stress conditions. Journal if American Science, 6, 34-41.
Kocheva, K. & Gorgek, G. (2003). Evaluation of the reaction of two contrasting barley (Hordeum vulgare L.) cultivars in response to osmotic stress with PEG 6000. Bulgarian Journal of Plant Physiology, 49, 290-294.
Kramer, P.J. & Benjamin, J. (1995). Water relations of plants and soils. Academic Press, San Diego, 69, 489-500.
Kumar, A. & Samjen, D. (1998). Use of Physiological Indices as a Screening Technique for Drought Tolerance in Oilseed Brassica Species." Annals of Botany, 81, 413-420.
Li, R., Baum, M., Grando, M. & Ceccarelli, S. (2008). Evaluation of Chlorophyll Content and Fluorescence Parameters as Indicators of Drought Tolerance in Barley. Agricalture Science in China, 5, 751-757.
Mahajan, S. & Amania, T. (2005). Cold, sallinity and drought stresses: An overview. Arch. of biochem. Biophysical Journal, 444, 139-158.
Morgan, J.M., Antonia, C. & Arevana, G. (1989). Water-use, grain yield and osmoregulation in wheat. Australian Journal Plant Physiology, 13, 523-532.
Nevo, E. & Comar, G. (2010). Drought and salt tolerances in wild relatives for wheat and barley improvement. Plant, Cell & Environment, 33, 670-685.
Niknam, S.R., Morgan, Q. & Turner, D.W. (2003). Osmotic adjustment and seed yield of Brassica napus and B. juncea genotypes in a water-limited environment in south-western Australia. Australian journal of experimental agriculture, 43, 1127-1135.
Nik khah, A.R. (2007). The final report of the project terminal drought tolerance in barley cultivars and advanced lines. Page 72. Registration number: 86/1495. (In Farsi)
Olivares-Villegas, J. M., Reynolds, M. & Mcdonald, R. (2007). Drought-adaptive attributes in the Seri/Babax hexaploid. Australian journal of experimental agriculture, 43, 1127-1135.
Passioura, J.B. (1988). Root signals control leaf expansion in wheat seedlings growing in drying soils. Austrlian Journal Plant Physiology, 15, 687-693.
Reynolds, T.L. & Jordan, D. (2009). Abscisic acid enhances the ability of the dessication -tolerant fern Polypodium virginianum to withstand drying. Journal of Experimental Botany, 269, 1771-1779.
Richards, R. A. (2004). Physiological traits used in the breeding of new cultivars for water scarce environments. In New directions for a diverse planet. Proceedings of the 4th International Crop Sciences Congress. Brisbane, Australia, 26 September - 1 October 2004.
Siva, M.A., Da Silva, J.A. & Sharma, S. (2007). Use of physiology parameters as fast tools to screen for drought tolerance in sugarcane. Brazilian Journal of Plant Physiology, 19, 193-201.
Taiz, L. & Zeiger, E. (2002). Plant physiology. (3rd edn). Sunderland, MA. Sinauer Associates Publishers.
Tuberosa, R. (2011). Phenotyping for drought tolerance of cropin the genomics era: Key concepts, issues and approaches. University of Bolongna, Italy.Frontiers in Physiology Journal, 3, 1-26
Turner, N. (1986). Crop water deficits: a decade of progres. Advances in Agronomy, 39, 1-15.
Vaezi, B., Borman, V. & Shiran, B. (2010). Screening of barley genotypes for drought tolerance by agro-physiological traits in field condition. African Journal of Agricultural Research, 5, 881-892.
Wright, P.R., Morgan, J. & Jessop, R.S. (1996). Comparative adaptation of canola (Brassica napus) and Indian mustard (B. juncea) to soil water deficits. Plant water relations and growth Field crops research, 49, 51-64.
Zahravi, M. (2009). Evaluation of Genotypes of Wild Barley (Hordeum spontaneum) Based on Drought Tolerance Indices. Seed and PlantJournal, 25, No. 4-Volume 1. (In Farsi)