تأثیر سطوح آبیاری بر بهبود تحمل به تنش یخ‌زدگی در گیاه بنفشه در شرایط کنترل شده

نوع مقاله : مقالات پژوهشی

نویسندگان

فردوسی مشهد

چکیده

به منظور بررسی اثر تنش خشکی بر تحمل به یخ‌زدگی گیاهان بنفشه، آزمایشی به صورت فاکتوریل و در قالب طرح کاملأ تصادفی با سه تکرار در دانشکده کشاورزی دانشگاه فردوسی مشهد در سال 1394 انجام شد. عوامل آزمایش شامل سه سطوح آبیاری (80، 60 و 40 درصد ظرفیت زراعی) و 10 سطح دمایی (20، صفر، 3-، 6-، 9-، 12-، 15-، 18-، 21- و 24- درجه سانتی‌گراد) بود. گیاهان پس از گذراندن دوره خوسرمایی در معرض تیمارهای آبیاری قرار گرفتند و سپس برای تنش یخ‌زدگی به فریزر ترموگرادیان انتقال یافتند. نتایج نشان داد که هر چند با کاهش دما درصد نشت الکترولیت‌ها در گیاهان هر سه تیمار آبیاری افزایش یافت، اما میزان آن در تیمار 80 درصد ظرفیت زراعی نسبت به دو تیمار دیگر به ترتیب 32 و 10 درصد بیشتر بود. گیاهان تحت تیمار (به جز 80 درصد ظرفیت زراعی) توانستند کاهش دما تا 21- درجه سانتی‌گراد را تحمل کنند. تیمارهای80 و 40 درصد ظرفیت زراعی در دمای 18- درجه سانتی‌گراد بیشترین و کمترین (به ترتیب 74 و 42 درصد) کاهش سطح برگ را نسبت به تیمار شاهد داشتند. اجزاء زایشی به طور معنی‌داری تحت تأثیر تیمارهای دمایی و آبیاری قرار گرفتند. گیاهان تحت تیمار 60 درصد ظرفیت زراعی در دمای صفر درجه سانتی‌گراد بیشترین افزایش (به ترتیب 55، 62 و 64 درصد) وزن خشک اجزاء رویشی، زایشی و کل را نسبت به شاهد به خود اختصاص دادند. وجود همبستگی منفی و معنی‌داری بین درصد بقاء و دمای کشنده 50 درصد گیاهان بر‌اساس درصد بقاء (LT50su) مشاهده شد (**95/0=- r). نتایج همچنین نشان داد که در گیاهان، با کاهش درصد نشت الکترولیت‌ها، دمای کشنده 50 درصد نمونه‌ها بر اساس نشت الکترولیت‌ها (LT50el) و دمای کاهنده 50 درصد وزن خشک گیاه (RDMT50) به طور معنی‌داری کاهش یافته است. با توجه به نتایج، به نظر می‌رسد که با اعمال تیمار آبیاری 60 درصد ظرفیت زراعی مقاومت گیاهان بنفشه در برابر تنش یخ‌زدگی افزایش می‌یابد.

کلیدواژه‌ها


عنوان مقاله [English]

The Effect of Irrigation Levels on Improvement of Cold Tolerance in Viola Plants under Controlled Conditions

نویسندگان [English]

  • A. Oraee
  • .A Tehranifar
  • .A Nezami
  • .M Shoor
Ferdowsi University of Mashhad
چکیده [English]

Introduction: Climate change is expected to have impacts on ecosystems worldwide. During the last 50 years, the greatest warming trends have been observed in winter months and significant increases in both the occurrence and duration of winter warming have already been reported. In general, predicted future climate change scenarios will result in less than optimal cold acclimation conditions, leading to decreases in freezing tolerance and predisposition of plants to winter injury. Nonetheless, it is not clear whether water stress induced during cold hardening is of high importance in inducing freezing tolerance in plants or it is an integral part of typical cold hardening process. Since rapid and effective assessment of plant cold tolerance is important for researchers and also field trials have no regular process and have high error, different kinds of artificial freeze tests such as survival percentage test and regrowth after imposing stress have been developed.
Materials and Methods: In order to evaluate the effect of drought stress on plant freezing tolerance of viola, a factorial experiment was conducted based on completely randomized design with three replications in faculty of Agriculture, Ferdowsi University of Mashhad. Experimental factors include three water treatments (80% FC, 60 % FC and 40% FC) and 10 temperature levels (Control, from zero to -24 with 3 °C intervals). Pansy seeds sown in a nursery in the summer of 2015 and after reaching the five-leaf stage in the fall plants were transferred to the pots. After the potted plants spend cold acclimation in nature conditions, plants were subjected to water stress including control (80% FC), 60% and 40% FC for two weeks. After drought stress, whole plants were sampled for freezing tolerance assessment and they were transferred to the freezer thermos-gradient. After applying the stress, electrolyte leakage, lethal temperature 50 according to the electrolyte leakage percentage (LT50el) were measured. One months later, survival percentage, lethal temperature 50% of plant according to the survival percentage (LT50su), leaf area, number of flower and bud, dry weight (dry weight of vegetative, reproductive, root and total) and reduced dry matter temperature 50 (RDMT50) were evaluated.
Results and Discussion: Electrolyte leakage percentage (EL %) and survival (%) were significantly (p ≤ 0.01) affected by irrigation treatments in the freezing conditions. By lowering the temperature from 20 to -24 °C, the EL% significantly increased in three irrigation treatments and it increased in 80% FC compared to 60% (by 16%) at -24°C. plants under 60% FC treatment exhibited higher baseline freezing tolerance (LT50 of −18.4 °C) compared to 80% FC (LT50 of −11.8 °C).Treated plants (except 80% FC) were able to tolerate lowering the temperature to -21°C. Lowering the temperature to -24°C caused the total mortality. According to the LT50su index, 60% FC treatment was less than compared to other treatments. Leaf area significantly increased by 16%, respectively, when plants were under water deficit (60% FC) compared to 80% FC at 0 °C. The maximum number of flower were seen in 60% FC at – 3 °C and the maximum number of bud were observed at 0 °C. The results showed that dry weight was significantly (p ≤ 0.01) increased by drought stress in the freezing conditions. Plants under 60% FC at 0 °C had the highest increase (55, 62 and 64%, respectively) dry weight of vegetative, reproductive and total growth, respectively compared to control. By lowering the temperature to -18 °C in 80% FC vegetative, reproductive and root growth decreased (36, 38 and 42%, respectively) compared to control plants. RDMT50 significantly affected by drought stress. There were significantly correlation between EL with LT50el and RDMT50 (r =0.25* and r = 0.72**, respectively). In total, plants under 60% FC showed highest freezing tolerance compared to the other treatments.
Conclusions: In the current study, we found that the greatest gain in freezing tolerance was associated with cold and that the effect of drought stress on freezing tolerance varied with temperature. Drought stress resulted in an improvement in freezing tolerance of viola (lower LT50). Among the different parameters evaluated, 60% FC treatment at 0 °C most consistently induced increases in survival percentage, reproductive and vegetative growth which suggested a synergistic effect between drought exposure and low temperature. Higher dry weight of viola plants may contribute to better plant overwintering capacity. In addition, future research should explore the effect of repeated mild drought events on freezing tolerance of acclimated plants, by using strategies such as wilt-based irrigation scheduling, partial root zone drying, and deficit irrigation.

کلیدواژه‌ها [English]

  • Winter survival
  • climate changing
  • lethal temperature
  • Hardening
  • Freezing
- Anderson J.A., Michael P., and Taliaferro C.M. 1988. Cold hardiness of midiron and Tifgreen. Horticultural Science 23: 748-750.
- Azizi H., Nezami A., Nassiri M., and Khazaie H.R. 2007. Evaluation of cold tolerance in wheat (Triticum aestivum L.) cultivars under controlled conditions. Iranian Journal of Field Crops Research 5: 109-121. (In Persian with English abstract)
- Bagheri a., Nezami A., and Soltani M. 2000. Cool season crops modified for tolerance to stress. Publication of Research, Education and Extension. Mashhad.(In Persian)
- Campbell G.S., and Mulla D.J. 1990. Measurement of soil water content and potential. Chapter 6 In Stewart B.A. and Nielsen D.R. (co-editors). Irrigation of Agricultural Crops. American Society of Agronomy. Madison, USA pp 127-142.
- Chinnusamy V., Schumaker K., and Zhu J.K. 2004. Molecular genetic perspectives on cross-talk and specificity in abiotic stress signaling in plants. Journal Experimental Botany 55: 225-236.
- Dole J.M., and Wilkins H.F. 2004. Floriculture (Principles and Species). Second edition. Pearson Prentice Hall. New Jersey.P.995.
- Ercoli L., Mariotti M., Masoni A., and Arduini I. 2004. Growth responses of sorghum plants to chilling temperature and duration of exposure. European Journal of Agronomy 21: 93-103.
- Gusta L.V., Fowler D.B., and Tyler N.J. 1982. Factors influencing hardening and survival in winter wheat. In: Li P.H., and Sakai A. (eds.). Plant Cold Hardiness and Freezing Stress.Academic press. New York.
- Gusta L.V., Wisniewski M., Nesbitt N., and Tanino K. 2003. Factors to consider in artificial freeze tests. Intl. Congress. Acta Hortic. 618:493-507.
- Hekneby M., Antolin M.C., and Sanchez-Diaz M. 2006. Frost resistance and biochemical changes during cold acclimation in different annual legumes. Environmental Experimental Botany 55: 305-314.
- Hoffman L., DaCosta M., Ebdon J.S., and Zhao J. 2012. Effects of drought preconditioning on freezing tolerance of perennial ryegrass. Environmental and Experimental Botany 79: 11-20.
- Iles J.K., and Howard Agnew N. 1993. Determining cold hardiness of Heuchera sanguine Engelm‘Chatterbox’ using dormant crowns. Horticultural Science 28: 1087-1088.
- Jiang Y., and Huang B. 2001. Osmotic adjustment and root growth associated with drought preconditioning enhanced heat tolerance in Kentucky bluegrass. Crop Science 41: 1168-1173.
- Khalighi A. 2000. Floriculture: Breeding of Ornamental Plants. Golshan Publications. Tehran, Iran. 392 pp. (In Persian)
- Khorsandi T. 2013. Evaluation of late spring cold tolerance in black cumin (Nigella sativa L.) ecotypes under controlled conditions. MSc Thesis. Faculty of Agriculture, Ferdowsi University of Mashhad. (In Persain with English abstract)
- Kim D.C., and Anderson N.O. 2006.Comparative analysis of laboratory freezing methods to establish cold tolerance of detached rhizomes and intact crowns in garden chrysanthemums (Dendranthema- grandiflora Tzvelv.). Scientia Horticulturae 109: 345-352.
- Lopez R., Rodriguez-Calcerrada J., and Gil L. 2009. Physiological and morphological responses to water deficit in seedlings of five provenances of Pinus canariensis: potential to detect variation indrought tolerance. Trees-Structure and Function 23: 509-519.
- Mahfoozi S., Limin A.E., and Fowler D.B. 2001. Influence of vernalization and photoperiod responses and cold hardiness in winter cereals. Crop Science 41: 1006-1011.
- Medeiros J.S., and Pockman W.T. 2011. Drought increases freezing tolerance of both leaves and xylem of Larrea tridentate. Plant, Cell and Environment 34: 43-51.
- Metwally A.S., Khalid A.K., and Abou-Leila B.H. 2013. Effect of water regime on the growth, flower yield, essential oil and proline contents of Calendula officinalis .Bioscience 5: 65-69.
- Mirmohamadi Meibodi A., and Tarkeshe Esfahani C. 2004. Aspects of Physiology and breeding for cold and freezing in crops. Golbon Publication, Isfahan, Iran 223 pp. (In Persian)
- Mousavi J.M., Nezami S., Izadi E., Nezami A., Yousef Sani M., Keykha Akhar F. 2011. Evaluation of freezing tolerance of English daisy (Bellis perennis) under controlled conditions. J. Water and Soil 25: 380-388. (In Persian with English abstract)
- Nezami A., and Naghedinia N. 2010. Effects of freezing stress on electrolyte leakage of sufflower genotypes. Journal of Iranian Field Crop Research 7: 891-896.
- Nezami A., Bagheri A., Rahimian H., Kafi M., and Nasiri Mahallati M. 2006. Evaluation of freezing tolerance in chickpea (Cicer aritinum) genotypes in controlled condition. Journal of Sciences and Technology of Agriculture and Natural Resources 4: 257-268.
- Nezami A., Hajmohammadnia- Ghalibaf K., and Kamandi A. 2010. Evaluation of freeze tolerance of sugarbeet cultivars (Beta vulgaris L.) in controlled conditions. Environmental Stress in Crop Sciences 3: 177-187. (In Persian with English abstract)
- Nezami A., Javad Mousavi M., Nezami S., Izadi Darbandi E., Yousef Sani M., and Keykha Akhar F. 2014. Study on freezing tolerance of calendula (Calendula officinalis L.) in vegetative and reproductive stages. Journal of Horticultural Science 28: 378-369. (In Persian with English abstract)
- Nezami A., Keykhah F., Javad Mousavi M., Izadi Darbandi A., Nezami S., and Yousef Sani M. 2012. Effect of freezing stress on viola (Viola gracilis L.) in controlled condition. Journal of Agroecology 3: 430-438. (In Persian with English abstract)
- Nezami A., Manjula S.B., and Gusta L.V. 2012. An evaluation of freezing tolerance of winter chickpea (Cicer arientinum L.) using controlled freeze tests. Canadian Journal of Plant Science 92: 155-161.
- Nezami, A., 2002. Evaluation of cold tolerance of chickpea (Cicer arietinum L.) for fall planting in the highlands. Ph.D. Thesis. Faculty of Agriculture, Ferdowsi University of Mashhad, Iran. (In Persian with English abstract)
- Pearce R.S. 2001. Plant freezing and damage. Annals of Botany 87: 417-424.
- Pietsch G.M., Anderson N.O., and Li P.H. 2009.Cold tolerance and short day acclimation in perennial Gaura coccinea and G. drummondii. Scientia Horticulturae 120: 418–425.
- Rajashekar C.B., and Panda M. 2014. Water stress is a component of cold acclimation process essential for inducing full freezing tolerance in strawberry. Scientia Horticulturae 174: 54-59.
- Rashed Mohassel M.H., Nezami A., Bagheri A.R., Hajmohammadnia K., and Bannayan M. 2009. Evaluation of freezing tolerance of two fennel (Foeniculum vulgar L.) ecotypes under controlled conditions. Journal of Herbs Species and Medicinal Plants 15: 131–140.
- Serrano L., Peñuelas J., Ogaya R., and Save R. 2005. Tissue–water relations of two co-occurring evergreen Mediterranean species in response to seasonal and experimental drought conditions. Journal of Plant Research 118: 263-269.
- Singh K.B., Malhotra R.S., Saxena M.C., and Bejia G.1997. Superiority of winter sowing over traditional spring sowing of chickpea in the Mediterranean region. Agronomy Journal 89: 112-118.
- Thapa B., Arora R., Knapp A., and Brummer E.C. 2008. Applying Freezing Test to Quantify Cold Acclimation in Medicago truncatula. Journal of American. Society. Horticultural Science 133:684–686.
- Xuan J., Liu J., Gao H., Huaguabghu H., and Cheng X. 2009. Evaluation of low-temperature tolerance of Zoysia grass. Tropical Grasslands 43: 118-124.
- Zhang Q., Fry J., Rajashekar C., Bremer D., and Engelke M. 2009. Membrane polar lipid changes in Zoysiagrass rhizomes and their potential role in freezing tolerance. Journal of American Society in Horticultural Science 134:322-328.